PIC18F85J90 Family Data Sheet 64/80-Pin, High-Performance Microcontrollers with LCD Driver and nanoWatt Technology 2010 Microchip Technology Inc. DS39770C Note the following details of the code protection feature on Microchip devices: * Microchip products meet the specification contained in their particular Microchip Data Sheet. * Microchip believes that its family of products is one of the most secure families of its kind on the market today, when used in the intended manner and under normal conditions. * There are dishonest and possibly illegal methods used to breach the code protection feature. All of these methods, to our knowledge, require using the Microchip products in a manner outside the operating specifications contained in Microchip's Data Sheets. Most likely, the person doing so is engaged in theft of intellectual property. * Microchip is willing to work with the customer who is concerned about the integrity of their code. * Neither Microchip nor any other semiconductor manufacturer can guarantee the security of their code. Code protection does not mean that we are guaranteeing the product as "unbreakable." Code protection is constantly evolving. We at Microchip are committed to continuously improving the code protection features of our products. Attempts to break Microchip's code protection feature may be a violation of the Digital Millennium Copyright Act. If such acts allow unauthorized access to your software or other copyrighted work, you may have a right to sue for relief under that Act. Information contained in this publication regarding device applications and the like is provided only for your convenience and may be superseded by updates. It is your responsibility to ensure that your application meets with your specifications. MICROCHIP MAKES NO REPRESENTATIONS OR WARRANTIES OF ANY KIND WHETHER EXPRESS OR IMPLIED, WRITTEN OR ORAL, STATUTORY OR OTHERWISE, RELATED TO THE INFORMATION, INCLUDING BUT NOT LIMITED TO ITS CONDITION, QUALITY, PERFORMANCE, MERCHANTABILITY OR FITNESS FOR PURPOSE. Microchip disclaims all liability arising from this information and its use. Use of Microchip devices in life support and/or safety applications is entirely at the buyer's risk, and the buyer agrees to defend, indemnify and hold harmless Microchip from any and all damages, claims, suits, or expenses resulting from such use. No licenses are conveyed, implicitly or otherwise, under any Microchip intellectual property rights. Trademarks The Microchip name and logo, the Microchip logo, dsPIC, KEELOQ, KEELOQ logo, MPLAB, PIC, PICmicro, PICSTART, rfPIC and UNI/O are registered trademarks of Microchip Technology Incorporated in the U.S.A. and other countries. FilterLab, Hampshire, HI-TECH C, Linear Active Thermistor, MXDEV, MXLAB, SEEVAL and The Embedded Control Solutions Company are registered trademarks of Microchip Technology Incorporated in the U.S.A. Analog-for-the-Digital Age, Application Maestro, CodeGuard, dsPICDEM, dsPICDEM.net, dsPICworks, dsSPEAK, ECAN, ECONOMONITOR, FanSense, HI-TIDE, In-Circuit Serial Programming, ICSP, Mindi, MiWi, MPASM, MPLAB Certified logo, MPLIB, MPLINK, mTouch, Octopus, Omniscient Code Generation, PICC, PICC-18, PICDEM, PICDEM.net, PICkit, PICtail, PIC32 logo, REAL ICE, rfLAB, Select Mode, Total Endurance, TSHARC, UniWinDriver, WiperLock and ZENA are trademarks of Microchip Technology Incorporated in the U.S.A. and other countries. SQTP is a service mark of Microchip Technology Incorporated in the U.S.A. All other trademarks mentioned herein are property of their respective companies. (c) 2010, Microchip Technology Incorporated, Printed in the U.S.A., All Rights Reserved. Printed on recycled paper. Microchip received ISO/TS-16949:2002 certification for its worldwide headquarters, design and wafer fabrication facilities in Chandler and Tempe, Arizona; Gresham, Oregon and design centers in California and India. The Company's quality system processes and procedures are for its PIC(R) MCUs and dsPIC(R) DSCs, KEELOQ(R) code hopping devices, Serial EEPROMs, microperipherals, nonvolatile memory and analog products. In addition, Microchip's quality system for the design and manufacture of development systems is ISO 9001:2000 certified. DS39770C-page 2 2010 Microchip Technology Inc. PIC18F85J90 FAMILY 64/80-Pin, High-Performance Microcontrollers with LCD Driver and nanoWatt Technology Low-Power Features: Flexible Oscillator Structure: * * * * * * * Two Crystal modes, 4-25 MHz * Two External Clock modes, up to 40 MHz * Internal Oscillator Block: - 8 user-selectable frequencies from 31.25 kHz to 8 MHz * Secondary Oscillator using Timer1 @ 32 kHz * Fail-Safe Clock Monitor: - Allows for safe shutdown if peripheral clock fails Power-Managed modes: Run, Idle, Sleep Run current down to 7 A, typical Idle current down to 2.5 A, typical Sleep current down to 100 nA, typical Fast INTOSC start-up from Sleep, 1 s typical Two-Speed Oscillator Start-up reduces crystal stabilization wait time LCD Driver Module Features: Peripheral Highlights: * Direct LCD Panel Drive Capability: - Can drive LCD panel while in Sleep mode * Up to 48 Segments and 192 Pixels; Software Selectable * Programmable LCD Timing module: - Multiple LCD timing sources available - Up to 4 commons: static, 1/2, 1/3 or 1/4 multiplex - Static, 1/2 or 1/3 Bias configuration * Integrated Charge Pump Module with Voltage Boost * 1000 Erase/Write Cycle Flash Program Memory, Typical * Flash Retention: 20 Years Minimum * Self-Programmable under Software Control * Priority Levels for Interrupts * 8 x 8 Single-Cycle Hardware Multiplier * Extended Watchdog Timer (WDT): - Programmable period from 4 ms to 131s * In-Circuit Serial ProgrammingTM (ICSPTM) via Two Pins * In-Circuit Debug with 3 Breakpoints via Two Pins * Operating Voltage Range: 2.0V to 3.6V * On-Chip 2.5V Regulator Device Flash # Single-Word (bytes) Instructions SRAM Data Memory (bytes) MSSP I/O LCD (Pixels) Timers 8/16-Bit Program Memory CCP SPI Master I2CTM 10-Bit A/D (ch) Comparators Special Microcontroller Features: EUSART/ AUSART * High-Current Sink/Source: 25 mA/25 mA (PORTB and PORTC) * Sleep Current as Low as 100 nA * Up to Four External Interrupts * Four 8-Bit/16-Bit Timer/Counter modules: - Uses Timer1 * Two Capture/Compare/PWM (CCP) modules: - Capture is 16-bit, max. resolution 6.25 ns (TCY/16) - Compare is 16-bit, max. resolution 100 ns (TCY) - PWM output: PWM resolution is up to 10-bit * Master Synchronous Serial Port (MSSP) module with Two Modes of Operation: - 3-wire/4-wire SPI (supports all 4 SPI modes) - I2CTM Master and Slave modes * One Addressable USART module * One Enhanced USART module: - Supports LIN/J2602 - Auto-wake-up on Start bit and Break character - Auto-Baud Detect * 10-Bit, up to 12-Channel A/D Converter: - Auto-acquisition - Conversion available during Sleep * Two Analog Comparators * Programmable Reference Voltage for Comparators BOR/ LVD PIC18F63J90 8K 4096 1024 51 132 1/3 2 Y Y 1/1 12 2 Y PIC18F64J90 16K 8192 1024 51 132 1/3 2 Y Y 1/1 12 2 Y PIC18F65J90 32K 16384 2048 51 132 1/3 2 Y Y 1/1 12 2 Y PIC18F83J90 8K 4096 1024 67 192 1/3 2 Y Y 1/1 12 2 Y PIC18F84J90 16K 8192 1024 67 192 1/3 2 Y Y 1/1 12 2 Y PIC18F85J90 32K 16384 2048 67 192 1/3 2 Y Y 1/1 12 2 Y 2010 Microchip Technology Inc. DS39770C-page 3 PIC18F85J90 FAMILY Pin Diagrams 64-Pin TQFP RD7/SEG7 RD6/SEG6 RD5/SEG5 RD4/SEG4 RD3/SEG3 RD2/SEG2 RD1/SEG1 VSS VDD RD0/SEG0 RE7/CCP2(1)/SEG31 RE6/COM3 RE5/COM2 RE4/COM1 RE3/COM0 LCDBIAS3 Pins are up to 5.5V tolerant 64 63 62 61 60 59 58 57 56 55 54 53 52 51 50 49 RE1/LCDBIAS2 RE0/LCDBIAS1 RG0/LCDBIAS0 RG1/TX2/CK2 RF7/AN5/SS/SEG25 RF6/AN11/SEG24 RF5/AN10/CVREF/SEG23 RF4/AN9/SEG22 1 2 3 4 5 6 7 8 9 10 11 12 13 14 RF3/AN8/SEG21 RF2/AN7/C1OUT/SEG20 15 16 RG2/RX2/DT2/VLCAP1 RG3/VLCAP2 MCLR RG4/SEG26 VSS VDDCORE/VCAP 48 47 46 45 44 43 42 41 40 PIC18F63J90 PIC18F64J90 PIC18F65J90 39 38 37 36 35 34 33 RB0/INT0/SEG30 RB1/INT1/SEG8 RB2/INT2/SEG9 RB3/INT3/SEG10 RB4/KBI0/SEG11 RB5/KBI1/SEG29 RB6/KBI2/PGC VSS OSC2/CLKO/RA6 OSC1/CLKI/RA7 VDD RB7/KBI3/PGD RC5/SDO/SEG12 RC4/SDI/SDA/SEG16 RC3/SCK/SCL/SEG17 RC2/CCP1/SEG13 Note 1: RC7/RX1/DT1/SEG28 RC6/TX1/CK1/SEG27 RC0/T1OSO/T13CKI RA4/T0CKI/SEG14 RC1/T1OSI/CCP2(1)/SEG32 RA5/AN4/SEG15 VDD VSS RA0/AN0 RA1/AN1/SEG18 RA2/AN2/VREF- AVSS RA3/AN3/VREF+ AVDD ENVREG RF1/AN6/C2OUT/SEG19 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 The CCP2 pin placement depends on the CCP2MX bit setting. DS39770C-page 4 2010 Microchip Technology Inc. PIC18F85J90 FAMILY Pin Diagrams (Continued) 80-Pin TQFP RJ1/SEG33 RJ0 RD7/SEG7 RD6/SEG6 RD5/SEG5 RD4/SEG4 RD3/SEG3 RD2/SEG2 RD1/SEG1 VDD VSS RE7/CCP2(1)/SEG31 RD0/SEG0 RE6/COM3 RE5/COM2 RE4/COM1 RE3/COM0 LCDBIAS3 RH0/SEG47 RH1/SEG46 Pins are up to 5.5V tolerant 80 79 78 77 76 75 74 73 72 71 70 69 68 67 66 65 64 63 62 61 RH2/SEG45 RH3/SEG44 RE1/LCDBIAS2 RE0/LCDBIAS1 RG0/LCDBIAS0 RG1/TX2/CK2 RG2/RX2/DT2/VLCAP1 RG3/VLCAP2 MCLR RG4/SEG26 VSS VDDCORE/VCAP 1 60 59 2 3 58 57 4 5 6 7 8 9 56 55 54 53 52 PIC18F83J90 PIC18F84J90 PIC18F85J90 10 11 12 51 50 49 RF7/AN5/SS/SEG25 RF6/AN11/SEG24 RF5/AN10/CVREF/SEG23 RF4/AN9/SEG22 13 14 15 48 47 46 16 RF3/AN8/SEG21 RF2/AN7/C1OUT/SEG20 RH7/SEG43 17 18 45 44 RH6/SEG42 19 20 RJ2/SEG34 RJ3/SEG35 RB0/INT0/SEG30 RB1/INT1/SEG8 RB2/INT2/SEG9 RB3/INT3/SEG10 RB4/KBI0/SEG11 RB5/KBI1/SEG29 RB6/KBI2/PGC VSS OSC2/CLKO/RA6 OSC1/CLKI/RA7 VDD RB7/KBI3/PGD RC5/SDO/SEG12 43 42 RC4/SDI/SDA/SEG16 RC3/SCK/SCL/SEG17 RC2/CCP1/SEG13 RJ7/SEG36 41 RJ6/SEG37 Note 1: RJ5/SEG38 RJ4/SEG39 RC7/RX1/DT1/SEG28 RC6/TX1/CK1/SEG27 RC0/T1OSO/T13CKI RA4/T0CKI/SEG14 RC1/T1OSI/CCP2(1)I/SEG32 VDD RA5/AN4/SEG15 VSS RA0/AN0 RA1/AN1/SEG18 RA2/AN2/VREF- AVSS RA3/AN3/VREF+ AVDD ENVREG RF1/AN6/C2OUT/SEG19 RH4/SEG40 RH5/SEG41 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 The CCP2 pin placement depends on the CCP2MX bit setting. 2010 Microchip Technology Inc. DS39770C-page 5 PIC18F85J90 FAMILY Table of Contents 1.0 Device Overview .......................................................................................................................................................................... 9 2.0 Guidelines for Getting Started with PIC18FJ Microcontrollers ................................................................................................... 31 3.0 Oscillator Configurations ............................................................................................................................................................ 35 4.0 Power-Managed Modes ............................................................................................................................................................. 43 5.0 Reset .......................................................................................................................................................................................... 51 6.0 Memory Organization ................................................................................................................................................................. 63 7.0 Flash Program Memory .............................................................................................................................................................. 87 8.0 8 x 8 Hardware Multiplier............................................................................................................................................................ 97 9.0 Interrupts .................................................................................................................................................................................... 99 10.0 I/O Ports ................................................................................................................................................................................... 115 11.0 Timer0 Module ......................................................................................................................................................................... 137 12.0 Timer1 Module ......................................................................................................................................................................... 141 13.0 Timer2 Module ......................................................................................................................................................................... 147 14.0 Timer3 Module ......................................................................................................................................................................... 149 15.0 Capture/Compare/PWM (CCP) Modules ................................................................................................................................. 153 16.0 Liquid Crystal Display (LCD) Driver Module ............................................................................................................................. 163 17.0 Master Synchronous Serial Port (MSSP) Module .................................................................................................................... 191 18.0 Enhanced Universal Synchronous Asynchronous Receiver Transmitter (EUSART) ............................................................... 235 19.0 Addressable Universal Synchronous Asynchronous Receiver Transmitter (AUSART) ........................................................... 257 20.0 10-bit Analog-to-Digital Converter (A/D) Module ...................................................................................................................... 271 21.0 Comparator Module.................................................................................................................................................................. 281 22.0 Comparator Voltage Reference Module ................................................................................................................................... 287 23.0 Special Features of the CPU .................................................................................................................................................... 291 24.0 Instruction Set Summary .......................................................................................................................................................... 305 25.0 Development Support............................................................................................................................................................... 355 26.0 Electrical Characteristics .......................................................................................................................................................... 359 27.0 Packaging Information.............................................................................................................................................................. 393 Appendix A: Revision History............................................................................................................................................................. 399 Appendix B: Migration Between High-End Device Families............................................................................................................... 400 Index .................................................................................................................................................................................................. 403 The Microchip Web Site ..................................................................................................................................................................... 413 Customer Change Notification Service .............................................................................................................................................. 413 Customer Support .............................................................................................................................................................................. 413 Reader Response .............................................................................................................................................................................. 414 Product Identification System............................................................................................................................................................. 415 DS39770C-page 6 2010 Microchip Technology Inc. PIC18F85J90 FAMILY TO OUR VALUED CUSTOMERS It is our intention to provide our valued customers with the best documentation possible to ensure successful use of your Microchip products. To this end, we will continue to improve our publications to better suit your needs. Our publications will be refined and enhanced as new volumes and updates are introduced. If you have any questions or comments regarding this publication, please contact the Marketing Communications Department via E-mail at docerrors@microchip.com or fax the Reader Response Form in the back of this data sheet to (480) 792-4150. We welcome your feedback. Most Current Data Sheet To obtain the most up-to-date version of this data sheet, please register at our Worldwide Web site at: http://www.microchip.com You can determine the version of a data sheet by examining its literature number found on the bottom outside corner of any page. The last character of the literature number is the version number, (e.g., DS30000A is version A of document DS30000). Errata An errata sheet, describing minor operational differences from the data sheet and recommended workarounds, may exist for current devices. As device/documentation issues become known to us, we will publish an errata sheet. The errata will specify the revision of silicon and revision of document to which it applies. To determine if an errata sheet exists for a particular device, please check with one of the following: * Microchip's Worldwide Web site; http://www.microchip.com * Your local Microchip sales office (see last page) When contacting a sales office, please specify which device, revision of silicon and data sheet (include literature number) you are using. Customer Notification System Register on our web site at www.microchip.com to receive the most current information on all of our products. 2010 Microchip Technology Inc. DS39770C-page 7 PIC18F85J90 FAMILY NOTES: DS39770C-page 8 2010 Microchip Technology Inc. PIC18F85J90 FAMILY 1.0 DEVICE OVERVIEW This document contains device-specific information for the following devices: * PIC18F63J90 * PIC18F64J90 * PIC18F65J90 * PIC18F83J90 * PIC18F84J90 * PIC18F85J90 This family combines the traditional advantages of all PIC18 microcontrollers - namely, high computational performance and a rich feature set - with a versatile on-chip LCD driver, while maintaining an extremely competitive price point. These features make the PIC18F85J90 family a logical choice for many high-performance applications where price is a primary consideration. 1.1 1.1.1 Core Features nanoWatt TECHNOLOGY All of the devices in the PIC18F85J90 family incorporate a range of features that can significantly reduce power consumption during operation. Key items include: * Alternate Run Modes: By clocking the controller from the Timer1 source or the internal RC oscillator, power consumption during code execution can be reduced by as much as 90%. * Multiple Idle Modes: The controller can also run with its CPU core disabled but the peripherals still active. In these states, power consumption can be reduced even further, to as little as 4% of normal operation requirements. * On-the-Fly Mode Switching: The power-managed modes are invoked by user code during operation, allowing the user to incorporate power-saving ideas into their application's software design. 1.1.2 OSCILLATOR OPTIONS AND FEATURES All of the devices in the PIC18F85J90 family offer six different oscillator options, allowing users a range of choices in developing application hardware. These include: * Two Crystal modes, using crystals or ceramic resonators. * Two External Clock modes, offering the option of a divide-by-4 clock output. * A Phase Lock Loop (PLL) frequency multiplier, available to the External Oscillator modes which allows clock speeds of up to 40 MHz. * An internal oscillator block which provides an 8 MHz clock (2% accuracy) and an INTRC source (approximately 31 kHz, stable over temperature and VDD), as well as a range of six user-selectable clock frequencies, between 125 kHz to 4 MHz, for a total of eight clock frequencies. This option frees the two oscillator pins for use as additional general purpose I/O. 2010 Microchip Technology Inc. The internal oscillator block provides a stable reference source that gives the family additional features for robust operation: * Fail-Safe Clock Monitor: This option constantly monitors the main clock source against a reference signal provided by the internal oscillator. If a clock failure occurs, the controller is switched to the internal oscillator, allowing for continued low-speed operation or a safe application shutdown. * Two-Speed Start-up: This option allows the internal oscillator to serve as the clock source from Power-on Reset, or wake-up from Sleep mode, until the primary clock source is available. 1.1.3 MEMORY OPTIONS The PIC18F85J90 family provides a range of program memory options, from 8 Kbytes to 32 Kbytes of code space. The Flash cells for program memory are rated to last up to 1000 erase/write cycles. Data retention without refresh is conservatively estimated to be greater than 20 years. The PIC18F85J90 family also provides plenty of room for dynamic application data, with up to 2048 bytes of data RAM. 1.1.4 EXTENDED INSTRUCTION SET The PIC18F85J90 family implements the optional extension to the PIC18 instruction set, adding 8 new instructions and an Indexed Addressing mode. Enabled as a device configuration option, the extension has been specifically designed to optimize re-entrant application code originally developed in high-level languages, such as `C'. 1.1.5 EASY MIGRATION Regardless of the memory size, all devices share the same rich set of peripherals, allowing for a smooth migration path as applications grow and evolve. The consistent pinout scheme used throughout the entire family also aids in migrating to the next larger device. This is true when moving between the 64-pin members, between the 80-pin members, or even jumping from 64-pin to 80-pin devices. The PIC18F85J90 family is also largely pin compatible with other PIC18 families, such as the PIC18F8720 and PIC18F8722, as well as the PIC18F8490 family of microcontrollers with LCD drivers. This allows a new dimension to the evolution of applications, allowing developers to select different price points within Microchip's PIC18 portfolio, while maintaining a similar feature set. DS39770C-page 9 PIC18F85J90 FAMILY 1.2 LCD Driver 1.4 Details on Individual Family Members The on-chip LCD driver includes many features that make the integration of displays in low-power applications easier. These include an integrated voltage regulator with charge pump that allows contrast control in software and display operation above device VDD. Devices in the PIC18F85J90 family are available in 64-pin and 80-pin packages. Block diagrams for the two groups are shown in Figure 1-1 and Figure 1-2. 1.3 1. Other Special Features * Communications: The PIC18F85J90 family incorporates a range of serial communication peripherals, including an Addressable USART, a separate Enhanced USART that supports LIN/J2602 Specification 1.2, and one Master SSP module capable of both SPI and I2CTM (Master and Slave) modes of operation. * CCP Modules: All devices in the family incorporate two Capture/Compare/PWM (CCP) modules. Up to four different time bases may be used to perform several different operations at once. * 10-Bit A/D Converter: This module incorporates programmable acquisition time, allowing for a channel to be selected and a conversion to be initiated without waiting for a sampling period and thus, reducing code overhead. * Extended Watchdog Timer (WDT): This enhanced version incorporates a 16-bit prescaler, allowing an extended time-out range that is stable across operating voltage and temperature. See Section 26.0 "Electrical Characteristics" for time-out periods. DS39770C-page 10 The devices are differentiated from each other in four ways: 2. 3. 4. Flash program memory (three sizes, ranging from 8 Kbytes for PIC18FX3J90 devices to 32 Kbytes for PIC18FX5J90 devices). Data RAM (1024 bytes for PIC18FX3J90 and PIC18FX4J90 devices, 2048 bytes for PIC18FX5J90 devices). I/O ports (7 bidirectional ports on 64-pin devices, 9 bidirectional ports on 80-pin devices). LCD Pixels: 132 pixels (33 SEGs x 4 COMs) can be driven by 64-pin devices; 192 pixels (48 SEGs x 4 COMs) can be driven by 80-pin devices. All other features for devices in this family are identical. These are summarized in Table 1-1 and Table 1-2. The pinouts for all devices are listed in Table 1-3 and Table 1-4. 2010 Microchip Technology Inc. PIC18F85J90 FAMILY TABLE 1-1: DEVICE FEATURES FOR THE PIC18F85J90 FAMILY (64-PIN DEVICES) Features PIC18F63J90 Operating Frequency Program Memory (Bytes) PIC18F64J90 PIC18F65J90 DC - 40 MHz 8K 16K 32K Program Memory (Instructions) 4096 8192 16384 Data Memory (Bytes) 1024 1024 2048 Interrupt Sources 27 I/O Ports Ports A, B, C, D, E, F, G LCD Driver (available pixels to drive) 132 (33 SEGs x 4 COMs) Timers 4 Capture/Compare/PWM Modules 2 Serial Communications MSSP, Addressable USART, Enhanced USART 10-Bit Analog-to-Digital Module Resets (and Delays) Instruction Set 12 Input Channels POR, BOR, RESET Instruction, Stack Full, Stack Underflow, MCLR, WDT (PWRT, OST) 75 Instructions, 83 with Extended Instruction Set enabled Packages 64-pin TQFP TABLE 1-2: DEVICE FEATURES FOR THE PIC18F85J90 FAMILY (80-PIN DEVICES) Features PIC18F83J90 Operating Frequency Program Memory (Bytes) PIC18F84J90 PIC18F85J90 DC - 40 MHz 8K 16K 32K Program Memory (Instructions) 4096 8192 16384 Data Memory (Bytes) 1024 1024 2048 Interrupt Sources I/O Ports LCD Driver (available pixels to drive) 27 Ports A, B, C, D, E, F, G, H, J 192 (48 SEGs x 4 COMs) Timers 4 Capture/Compare/PWM Modules 2 Serial Communications 10-Bit Analog-to-Digital Module Resets (and Delays) Instruction Set Packages 2010 Microchip Technology Inc. MSSP, Addressable USART, Enhanced USART 12 Input Channels POR, BOR, RESET Instruction, Stack Full, Stack Underflow, MCLR, WDT (PWRT, OST) 75 Instructions, 83 with Extended Instruction Set enabled 80-pin TQFP DS39770C-page 11 PIC18F85J90 FAMILY FIGURE 1-1: PIC18F6XJ90 (64-PIN) BLOCK DIAGRAM Data Bus<8> Table Pointer<21> Address Latch 20 PCU PCH PCL Program Counter 12 Data Address<12> 31 Level Stack 4 BSR Address Latch Program Memory (96 Kbytes) STKPTR 12 PORTC RC0:RC7(1) inc/dec logic Table Latch Instruction Bus <16> PORTB RB0:RB7(1) 4 Access Bank 12 FSR0 FSR1 FSR2 Data Latch 8 RA0:RA7(1,2) Data Memory (2.0, 3.9 Kbytes) PCLATU PCLATH 21 PORTA Data Latch 8 8 inc/dec logic Address Decode ROM Latch PORTD RD0:RD7(1) IR Instruction Decode and Control OSC2/CLKO OSC1/CLKI Power-up Timer INTRC Oscillator 8 MHz Oscillator Oscillator Start-up Timer ENVREG Voltage Regulator PORTE RE0:RE1, RE3:RE7(1) PRODH PRODL 3 Timing Generation Precision Band Gap Reference 8 State Machine Control Signals 8 x 8 Multiply 8 BITOP W 8 8 8 8 Power-on Reset PORTF 8 RF1:RF7(1) ALU<8> Watchdog Timer 8 BOR and LVD(3) PORTG RG0:RG4(1) VDDCORE/VCAP Note 1: VDD, VSS MCLR Timer0 Timer1 Timer2 Timer3 ADC 10-Bit Comparators CCP1 CCP2 AUSART EUSART MSSP LCD Driver See Table 1-3 for I/O port pin descriptions. 2: RA6 and RA7 are only available as digital I/O in select oscillator modes. See Section 3.0 "Oscillator Configurations" for more information 3: Brown-out Reset and Low-Voltage Detect functions are provided when the on-board voltage regulator is enabled. DS39770C-page 12 2010 Microchip Technology Inc. PIC18F85J90 FAMILY FIGURE 1-2: PIC18F8XJ90 (80-PIN) BLOCK DIAGRAM Data Bus<8> Table Pointer<21> 20 Address Latch PCU PCH PCL Program Counter 31 Level Stack 4 BSR STKPTR PORTC RC0:RC7(1) 12 inc/dec logic Table Latch Instruction Bus <16> RB0:RB7(1) 4 Access Bank 12 FSR0 FSR1 FSR2 Data Latch 8 PORTB 12 Data Address<12> Address Latch Program Memory (96 Kbytes) RA0:RA7(1,2) Data Memory (2.0, 3.9 Kbytes) PCLATU PCLATH 21 PORTA Data Latch 8 8 inc/dec logic PORTD RD0:RD7(1) Address Decode ROM Latch PORTE RE0:RE1, RE3:RE7(1) IR Instruction Decode and Control OSC2/CLKO OSC1/CLKI ENVREG Power-up Timer INTRC Oscillator 8 MHz Oscillator Oscillator Start-up Timer Voltage Regulator BOR and LVD(3) RF1:RF7(1) 8 x 8 Multiply 8 BITOP W 8 8 8 8 Power-on Reset Watchdog Timer PORTF PRODH PRODL 3 Timing Generation Precision Band Gap Reference 8 State Machine Control Signals PORTG RG0:RG4(1) 8 ALU<8> PORTH RH0:RH7(1) 8 PORTJ VDDCORE/VCAP Note 1: VDD,VSS RJ0:RJ7(1) MCLR Timer0 Timer1 Timer2 Timer3 ADC 10-Bit Comparators CCP1 CCP2 AUSART EUSART MSSP LCD Driver See Table 1-3 for I/O port pin descriptions. 2: RA6 and RA7 are only available as digital I/O in select oscillator modes. See Section 3.0 "Oscillator Configurations" for more information. 3: Brown-out Reset and Low-Voltage Detect functions are provided when the on-board voltage regulator is enabled. 2010 Microchip Technology Inc. DS39770C-page 13 PIC18F85J90 FAMILY TABLE 1-3: PIC18F6XJ90 PINOUT I/O DESCRIPTIONS Pin Name Pin Number TQFP MCLR 7 OSC1/CLKI/RA7 OSC1 CLKI 39 Pin Buffer Type Type I ST I I CMOS CMOS I/O TTL O -- CLKO O -- RA6 I/O TTL RA7 OSC2/CLKO/RA6 OSC2 40 Description Master Clear (input) or programming voltage (input). This pin is an active-low Reset to the device. Oscillator crystal or external clock input. Oscillator crystal input. External clock source input. Always associated with pin function OSC1. (See related OSC1/CLKI, OSC2/CLKO pins.) General purpose I/O pin. Oscillator crystal or clock output. Oscillator crystal output. Connects to crystal or resonator in Crystal Oscillator mode. In EC modes, OSC2 pin outputs CLKO, which has 1/4 the frequency of OSC1 and denotes the instruction cycle rate. General purpose I/O pin. PORTA is a bidirectional I/O port. RA0/AN0 RA0 AN0 24 RA1/AN1/SEG18 RA1 AN1 SEG18 23 RA2/AN2/VREFRA2 AN2 VREF- 22 RA3/AN3/VREF+ RA3 AN3 VREF+ 21 RA4/T0CKI/SEG14 RA4 T0CKI SEG14 28 RA5/AN4/SEG15 RA5 AN4 SEG15 27 I/O I TTL Analog Digital I/O. Analog Input 0. I/O I O TTL Analog Analog Digital I/O. Analog Input 1. SEG18 output for LCD. I/O I I TTL Analog Analog Digital I/O. Analog Input 2. A/D reference voltage (low) input. I/O I I TTL Analog Analog Digital I/O. Analog Input 3. A/D reference voltage (high) input. I/O I O ST/OD ST Analog Digital I/O. Open-drain when configured as output. Timer0 external clock input. SEG14 output for LCD. I/O I O TTL Analog Analog Digital I/O. Analog Input 4. SEG15 output for LCD. RA6 See the OSC2/CLKO/RA6 pin. RA7 See the OSC1/CLKI/RA7 pin. Legend: TTL = TTL compatible input CMOS = CMOS compatible input or output ST = Schmitt Trigger input with CMOS levels Analog = Analog input I = Input O = Output P = Power OD = Open-Drain (no P diode to VDD) I2CTM = I2C/SMBus Note 1: Default assignment for CCP2 when the CCP2MX Configuration bit is set. 2: Alternate assignment for CCP2 when the CCP2MX Configuration bit is cleared. DS39770C-page 14 2010 Microchip Technology Inc. PIC18F85J90 FAMILY TABLE 1-3: PIC18F6XJ90 PINOUT I/O DESCRIPTIONS (CONTINUED) Pin Name Pin Number TQFP Pin Buffer Type Type Description PORTB is a bidirectional I/O port. PORTB can be software programmed for internal weak pull-ups on all inputs. RB0/INT0/SEG30 RB0 INT0 SEG30 48 RB1/INT1/SEG8 RB1 INT1 SEG8 47 RB2/INT2/SEG9 RB2 INT2 SEG9 46 RB3/INT3/SEG10 RB3 INT3 SEG10 45 RB4/KBI0/SEG11 RB4 KBI0 SEG11 44 RB5/KBI1/SEG29 RB5 KBI1 SEG29 43 RB6/KBI2/PGC RB6 KBI2 PGC 42 RB7/KBI3/PGD RB7 KBI3 PGD 37 I/O I O TTL ST Analog Digital I/O. External Interrupt 0. SEG30 output for LCD. I/O I O TTL ST Analog Digital I/O. External Interrupt 1. SEG8 output for LCD. I/O I O TTL ST Analog Digital I/O. External Interrupt 2. SEG9 output for LCD. I/O I O TTL ST Analog Digital I/O. External Interrupt 3. SEG10 output for LCD. I/O I O TTL TTL Analog Digital I/O. Interrupt-on-change pin. SEG11 output for LCD. I/O I O TTL TTL Analog Digital I/O. Interrupt-on-change pin. SEG29 output for LCD. I/O I I/O TTL TTL ST Digital I/O. Interrupt-on-change pin. In-Circuit Debugger and ICSPTM programming clock pin. I/O I I/O TTL TTL ST Digital I/O. Interrupt-on-change pin. In-Circuit Debugger and ICSP programming data pin. Legend: TTL = TTL compatible input CMOS = CMOS compatible input or output ST = Schmitt Trigger input with CMOS levels Analog = Analog input I = Input O = Output P = Power OD = Open-Drain (no P diode to VDD) I2CTM = I2C/SMBus Note 1: Default assignment for CCP2 when the CCP2MX Configuration bit is set. 2: Alternate assignment for CCP2 when the CCP2MX Configuration bit is cleared. 2010 Microchip Technology Inc. DS39770C-page 15 PIC18F85J90 FAMILY TABLE 1-3: PIC18F6XJ90 PINOUT I/O DESCRIPTIONS (CONTINUED) Pin Name Pin Number TQFP Pin Buffer Type Type Description PORTC is a bidirectional I/O port. RC0/T1OSO/T13CKI RC0 T1OSO T13CKI 30 RC1/T1OSI/CCP2/SEG32 RC1 T1OSI CCP2(1) SEG32 29 RC2/CCP1/SEG13 RC2 CCP1 SEG13 33 RC3/SCK/SCL/SEG17 RC3 SCK SCL SEG17 34 RC4/SDI/SDA/SEG16 RC4 SDI SDA SEG16 35 RC5/SDO/SEG12 RC5 SDO SEG12 36 RC6/TX1/CK1/SEG27 RC6 TX1 CK1 SEG27 31 RC7/RX1/DT1/SEG28 RC7 RX1 DT1 SEG28 32 I/O O I ST -- ST I/O I I/O O ST CMOS ST Analog Digital I/O. Timer1 oscillator input. Capture 2 input/Compare 2 output/PWM2 output. SEG32 output for LCD. I/O I/O O ST ST Analog Digital I/O. Capture 1 input/Compare 1 output/PWM1 output. SEG13 output for LCD. I/O I/O I/O O ST ST I2C Analog Digital I/O. Synchronous serial clock input/output for SPI mode. Synchronous serial clock input/output for I2CTM mode. SEG17 output for LCD. I/O I I/O O ST ST I2C Analog Digital I/O. SPI data in. I2C data I/O. SEG16 output for LCD. I/O O O ST -- Analog Digital I/O. SPI data out. SEG12 output for LCD. I/O O I/O O ST -- ST Analog Digital I/O. EUSART asynchronous transmit. EUSART synchronous clock (see related RX1/DT1). SEG27 output for LCD. I/O I I/O O ST ST ST Analog Digital I/O. EUSART asynchronous receive. EUSART synchronous data (see related TX1/CK1). SEG28 output for LCD. Digital I/O. Timer1 oscillator output. Timer1/Timer3 external clock input. Legend: TTL = TTL compatible input CMOS = CMOS compatible input or output ST = Schmitt Trigger input with CMOS levels Analog = Analog input I = Input O = Output P = Power OD = Open-Drain (no P diode to VDD) I2CTM = I2C/SMBus Note 1: Default assignment for CCP2 when the CCP2MX Configuration bit is set. 2: Alternate assignment for CCP2 when the CCP2MX Configuration bit is cleared. DS39770C-page 16 2010 Microchip Technology Inc. PIC18F85J90 FAMILY TABLE 1-3: PIC18F6XJ90 PINOUT I/O DESCRIPTIONS (CONTINUED) Pin Name Pin Number TQFP Pin Buffer Type Type Description PORTD is a bidirectional I/O port. RD0/SEG0 RD0 SEG0 58 RD1/SEG1 RD1 SEG1 55 RD2/SEG2 RD2 SEG2 54 RD3/SEG3 RD3 SEG3 53 RD4/SEG4 RD4 SEG4 52 RD5/SEG5 RD5 SEG5 51 RD6/SEG6 RD6 SEG6 50 RD7/SEG7 RD7 SEG7 49 I/O O ST Analog Digital I/O. SEG0 output for LCD. I/O O ST Analog Digital I/O. SEG1 output for LCD. I/O O ST Analog Digital I/O. SEG2 output for LCD. I/O O ST Analog Digital I/O. SEG3 output for LCD. I/O O ST Analog Digital I/O. SEG4 output for LCD. I/O O ST Analog Digital I/O. SEG5 output for LCD. I/O O ST Analog Digital I/O. SEG6 output for LCD. I/O O ST Analog Digital I/O. SEG7 output for LCD. Legend: TTL = TTL compatible input CMOS = CMOS compatible input or output ST = Schmitt Trigger input with CMOS levels Analog = Analog input I = Input O = Output P = Power OD = Open-Drain (no P diode to VDD) I2CTM = I2C/SMBus Note 1: Default assignment for CCP2 when the CCP2MX Configuration bit is set. 2: Alternate assignment for CCP2 when the CCP2MX Configuration bit is cleared. 2010 Microchip Technology Inc. DS39770C-page 17 PIC18F85J90 FAMILY TABLE 1-3: PIC18F6XJ90 PINOUT I/O DESCRIPTIONS (CONTINUED) Pin Name Pin Number TQFP Pin Buffer Type Type Description PORTE is a bidirectional I/O port. RE0/LCDBIAS1 RE0 LCDBIAS1 2 RE1/LCDBIAS2 RE1 LCDBIAS2 1 LCDBIAS3 64 RE3/COM0 RE3 COM0 63 RE4/COM1 RE4 COM1 62 RE5/COM2 RE5 COM2 61 RE6/COM3 RE6 COM3 60 RE7/CCP2/SEG31 RE7 CCP2(2) SEG31 59 I/O I ST Analog Digital I/O. BIAS1 input for LCD. I/O I ST Analog Digital I/O. BIAS2 input for LCD. I Analog BIAS3 input for LCD. I/O O ST Analog Digital I/O. COM0 output for LCD. I/O O ST Analog Digital I/O. COM1 output for LCD. I/O O ST Analog Digital I/O. COM2 output for LCD. I/O O ST Analog Digital I/O. COM3 output for LCD. I/O I/O O ST ST Analog Digital I/O. Capture 2 input/Compare 2 output/PWM2 output. SEG31 output for LCD. Legend: TTL = TTL compatible input CMOS = CMOS compatible input or output ST = Schmitt Trigger input with CMOS levels Analog = Analog input I = Input O = Output P = Power OD = Open-Drain (no P diode to VDD) I2CTM = I2C/SMBus Note 1: Default assignment for CCP2 when the CCP2MX Configuration bit is set. 2: Alternate assignment for CCP2 when the CCP2MX Configuration bit is cleared. DS39770C-page 18 2010 Microchip Technology Inc. PIC18F85J90 FAMILY TABLE 1-3: PIC18F6XJ90 PINOUT I/O DESCRIPTIONS (CONTINUED) Pin Name Pin Number TQFP Pin Buffer Type Type Description PORTF is a bidirectional I/O port. RF1/AN6/C2OUT/SEG19 RF1 AN6 C2OUT SEG19 17 RF2/AN7/C1OUT/SEG20 RF2 AN7 C1OUT SEG20 16 RF3/AN8/SEG21 RF3 AN8 SEG21 15 RF4/AN9/SEG22 RF4 AN9 SEG22 14 RF5/AN10/CVREF/SEG23 RF5 AN10 CVREF SEG23 13 RF6/AN11/SEG24 RF6 AN11 SEG24 12 RF7/AN5/SS/SEG25 RF7 AN5 SS SEG25 11 I/O I O O ST Analog -- Analog Digital I/O. Analog Input 6. Comparator 2 output. SEG19 output for LCD. I/O I O O ST Analog -- Analog Digital I/O. Analog Input 7. Comparator 1 output. SEG20 output for LCD. I/O I O ST Analog Analog Digital I/O. Analog input 8. SEG21 output for LCD. I/O I O ST Analog Analog Digital I/O. Analog Input 9. SEG22 output for LCD. I/O I O O ST Analog Analog Analog Digital I/O. Analog Input 10. Comparator reference voltage output. SEG23 output for LCD. I/O I O ST Analog Analog Digital I/O. Analog Input 11. SEG24 output for LCD. I/O O I O ST Analog TTL Analog Digital I/O. Analog Input 5. SPI slave select input. SEG25 output for LCD. Legend: TTL = TTL compatible input CMOS = CMOS compatible input or output ST = Schmitt Trigger input with CMOS levels Analog = Analog input I = Input O = Output P = Power OD = Open-Drain (no P diode to VDD) I2CTM = I2C/SMBus Note 1: Default assignment for CCP2 when the CCP2MX Configuration bit is set. 2: Alternate assignment for CCP2 when the CCP2MX Configuration bit is cleared. 2010 Microchip Technology Inc. DS39770C-page 19 PIC18F85J90 FAMILY TABLE 1-3: PIC18F6XJ90 PINOUT I/O DESCRIPTIONS (CONTINUED) Pin Name Pin Number TQFP Pin Buffer Type Type Description PORTG is a bidirectional I/O port. RG0/LCDBIAS0 RG0 LCDBIAS0 3 RG1/TX2/CK2 RG1 TX2 CK2 4 RG2/RX2/DT2/VLCAP1 RG2 RX2 DT2 VLCAP1 5 RG3/VLCAP2 RG3 VLCAP2 6 RG4/SEG26 RG4 SEG26 8 I/O I ST Analog Digital I/O. BIAS0 input for LCD. I/O O I/O ST -- ST Digital I/O. AUSART asynchronous transmit. AUSART synchronous clock (see related RX2/DT2). I/O I I/O I ST ST ST Analog Digital I/O. AUSART asynchronous receive. AUSART synchronous data (see related TX2/CK2). LCD charge pump capacitor input. I/O I ST Analog Digital I/O. LCD charge pump capacitor input. I/O O ST Analog Digital I/O. SEG26 output for LCD. VSS 9, 25, 41, 56 P -- Ground reference for logic and I/O pins. VDD 26, 38, 57 P -- Positive supply for logic and I/O pins. AVSS 20 P -- Ground reference for analog modules. AVDD 19 P -- Positive supply for analog modules. ENVREG 18 I ST Enable for on-chip voltage regulator. VDDCORE/VCAP VDDCORE 10 P -- P -- VCAP Core logic power or external filter capacitor connection. Positive supply for microcontroller core logic (regulator disabled). External filter capacitor connection (regulator enabled). Legend: TTL = TTL compatible input CMOS = CMOS compatible input or output ST = Schmitt Trigger input with CMOS levels Analog = Analog input I = Input O = Output P = Power OD = Open-Drain (no P diode to VDD) I2CTM = I2C/SMBus Note 1: Default assignment for CCP2 when the CCP2MX Configuration bit is set. 2: Alternate assignment for CCP2 when the CCP2MX Configuration bit is cleared. DS39770C-page 20 2010 Microchip Technology Inc. PIC18F85J90 FAMILY TABLE 1-4: PIC18F8XJ90 PINOUT I/O DESCRIPTIONS Pin Name Pin Number TQFP MCLR 9 OSC1/CLKI/RA7 OSC1 CLKI 49 Pin Buffer Type Type I ST I I CMOS CMOS I/O TTL O -- CLKO O -- RA6 I/O TTL RA7 OSC2/CLKO/RA6 OSC2 50 Description Master Clear (input) or programming voltage (input). This pin is an active-low Reset to the device. Oscillator crystal or external clock input. Oscillator crystal input. External clock source input. Always associated with pin function OSC1. (See related OSC1/CLKI, OSC2/CLKO pins.) General purpose I/O pin. Oscillator crystal or clock output. Oscillator crystal output. Connects to crystal or resonator in Crystal Oscillator mode. In EC modes, OSC2 pin outputs CLKO, which has 1/4 the frequency of OSC1 and denotes the instruction cycle rate. General purpose I/O pin. PORTA is a bidirectional I/O port. RA0/AN0 RA0 AN0 30 RA1/AN1/SEG18 RA1 AN1 SEG18 29 RA2/AN2/VREFRA2 AN2 VREF- 28 RA3/AN3/VREF+ RA3 AN3 VREF+ 27 RA4/T0CKI/SEG14 RA4 T0CKI SEG14 34 RA5/AN4/SEG15 RA5 AN4 SEG15 33 I/O I TTL Analog Digital I/O. Analog Input 0. I/O I O TTL Analog Analog Digital I/O. Analog Input 1. SEG18 output for LCD. I/O I I TTL Analog Analog Digital I/O. Analog Input 2. A/D reference voltage (low) input. I/O I I TTL Analog Analog Digital I/O. Analog Input 3. A/D reference voltage (high) input. I/O I O ST/OD ST Analog Digital I/O. Open-drain when configured as output. Timer0 external clock input. SEG14 output for LCD. I/O I O TTL Analog Analog Digital I/O. Analog Input 4. SEG15 output for LCD. RA6 See the OSC2/CLKO/RA6 pin. RA7 See the OSC1/CLKI/RA7 pin. Legend: TTL = TTL compatible input CMOS = CMOS compatible input or output ST = Schmitt Trigger input with CMOS levels Analog = Analog input I = Input O = Output P = Power OD = Open-Drain (no P diode to VDD) I2CTM = I2C/SMBus Note 1: Default assignment for CCP2 when the CCP2MX Configuration bit is set. 2: Alternate assignment for CCP2 when the CCP2MX Configuration bit is cleared. 2010 Microchip Technology Inc. DS39770C-page 21 PIC18F85J90 FAMILY TABLE 1-4: PIC18F8XJ90 PINOUT I/O DESCRIPTIONS (CONTINUED) Pin Name Pin Number TQFP Pin Buffer Type Type Description PORTB is a bidirectional I/O port. PORTB can be software programmed for internal weak pull-ups on all inputs. RB0/INT0/SEG30 RB0 INT0 SEG30 58 RB1/INT1/SEG8 RB1 INT1 SEG8 57 RB2/INT2/SEG9 RB2 INT2 SEG9 56 RB3/INT3/SEG10 RB3 INT3 SEG10 55 RB4/KBI0/SEG11 RB4 KBI0 SEG11 54 RB5/KBI1/SEG29 RB5 KBI1 SEG29 53 RB6/KBI2/PGC RB6 KBI2 PGC 52 RB7/KBI3/PGD RB7 KBI3 PGD 47 I/O I O TTL ST Analog Digital I/O. External Interrupt 0. SEG30 output for LCD. I/O I O TTL ST Analog Digital I/O. External Interrupt 1. SEG8 output for LCD. I/O I O TTL ST Analog Digital I/O. External Interrupt 2. SEG9 output for LCD. I/O I O TTL ST Analog Digital I/O. External Interrupt 3. SEG10 output for LCD. I/O I O TTL TTL Analog Digital I/O. Interrupt-on-change pin. SEG11 output for LCD. I/O I O TTL TTL Analog Digital I/O. Interrupt-on-change pin. SEG29 output for LCD. I/O I I/O TTL TTL ST Digital I/O. Interrupt-on-change pin. In-Circuit Debugger and ICSPTM programming clock pin. I/O I I/O TTL TTL ST Digital I/O. Interrupt-on-change pin. In-Circuit Debugger and ICSP programming data pin. Legend: TTL = TTL compatible input CMOS = CMOS compatible input or output ST = Schmitt Trigger input with CMOS levels Analog = Analog input I = Input O = Output P = Power OD = Open-Drain (no P diode to VDD) I2CTM = I2C/SMBus Note 1: Default assignment for CCP2 when the CCP2MX Configuration bit is set. 2: Alternate assignment for CCP2 when the CCP2MX Configuration bit is cleared. DS39770C-page 22 2010 Microchip Technology Inc. PIC18F85J90 FAMILY TABLE 1-4: PIC18F8XJ90 PINOUT I/O DESCRIPTIONS (CONTINUED) Pin Name Pin Number TQFP Pin Buffer Type Type Description PORTC is a bidirectional I/O port. RC0/T1OSO/T13CKI RC0 T1OSO T13CKI 36 RC1/T1OSI/CCP2/SEG32 RC1 T1OSI CCP2(1) SEG32 35 RC2/CCP1/SEG13 RC2 CCP1 SEG13 43 RC3/SCK/SCL/SEG17 RC3 SCK SCL SEG17 44 RC4/SDI/SDA/SEG16 RC4 SDI SDA SEG16 45 RC5/SDO/SEG12 RC5 SDO SEG12 46 RC6/TX1/CK1/SEG27 RC6 TX1 CK1 SEG27 37 RC7/RX1/DT1/SEG28 RC7 RX1 DT1 SEG28 38 I/O O I ST -- ST I/O I I/O O ST CMOS ST Analog Digital I/O. Timer1 oscillator input. Capture 2 input/Compare 2 output/PWM2 output. SEG32 output for LCD. I/O I/O O ST ST Analog Digital I/O. Capture 1 input/Compare 1 output/PWM1 output. SEG13 output for LCD. I/O I/O I/O O ST ST I2C Analog Digital I/O. Synchronous serial clock input/output for SPI mode. Synchronous serial clock input/output for I2CTM mode. SEG17 output for LCD. I/O I I/O O ST ST I2C Analog Digital I/O. SPI data in. I2C data I/O. SEG16 output for LCD. I/O O O ST -- Analog Digital I/O. SPI data out. SEG12 output for LCD. I/O O I/O O ST -- ST Analog Digital I/O. EUSART asynchronous transmit. EUSART synchronous clock (see related RX1/DT1). SEG27 output for LCD. I/O I I/O O ST ST ST Analog Digital I/O. EUSART asynchronous receive. EUSART synchronous data (see related TX1/CK1). SEG28 output for LCD. Digital I/O. Timer1 oscillator output. Timer1/Timer3 external clock input. Legend: TTL = TTL compatible input CMOS = CMOS compatible input or output ST = Schmitt Trigger input with CMOS levels Analog = Analog input I = Input O = Output P = Power OD = Open-Drain (no P diode to VDD) I2CTM = I2C/SMBus Note 1: Default assignment for CCP2 when the CCP2MX Configuration bit is set. 2: Alternate assignment for CCP2 when the CCP2MX Configuration bit is cleared. 2010 Microchip Technology Inc. DS39770C-page 23 PIC18F85J90 FAMILY TABLE 1-4: PIC18F8XJ90 PINOUT I/O DESCRIPTIONS (CONTINUED) Pin Name Pin Number TQFP Pin Buffer Type Type Description PORTD is a bidirectional I/O port. RD0/SEG0 RD0 SEG0 72 RD1/SEG1 RD1 SEG1 69 RD2/SEG2 RD2 SEG2 68 RD3/SEG3 RD3 SEG3 67 RD4/SEG4 RD4 SEG4 66 RD5/SEG5 RD5 SEG5 65 RD6/SEG6 RD6 SEG6 64 RD7/SEG7 RD7 SEG7 63 I/O O ST Analog Digital I/O. SEG0 output for LCD. I/O O ST Analog Digital I/O. SEG1 output for LCD. I/O O ST Analog Digital I/O. SEG2 output for LCD. I/O O ST Analog Digital I/O. SEG3 output for LCD. I/O O ST Analog Digital I/O. SEG4 output for LCD. I/O O ST Analog Digital I/O. SEG5 output for LCD. I/O O ST Analog Digital I/O. SEG6 output for LCD. I/O O ST Analog Digital I/O. SEG7 output for LCD. Legend: TTL = TTL compatible input CMOS = CMOS compatible input or output ST = Schmitt Trigger input with CMOS levels Analog = Analog input I = Input O = Output P = Power OD = Open-Drain (no P diode to VDD) I2CTM = I2C/SMBus Note 1: Default assignment for CCP2 when the CCP2MX Configuration bit is set. 2: Alternate assignment for CCP2 when the CCP2MX Configuration bit is cleared. DS39770C-page 24 2010 Microchip Technology Inc. PIC18F85J90 FAMILY TABLE 1-4: PIC18F8XJ90 PINOUT I/O DESCRIPTIONS (CONTINUED) Pin Name Pin Number TQFP Pin Buffer Type Type Description PORTE is a bidirectional I/O port. RE0/LCDBIAS1 RE0 LCDBIAS1 4 RE1/LCDBIAS2 RE1 LCDBIAS2 3 LCDBIAS3 78 RE3/COM0 RE3 COM0 77 RE4/COM1 RE4 COM1 76 RE5/COM2 RE5 COM2 75 RE6/COM3 RE6 COM3 74 RE7/CCP2/SEG31 RE7 CCP2(2) SEG31 73 I/O I ST Analog Digital I/O. BIAS1 input for LCD. I/O I ST Analog Digital I/O. BIAS2 input for LCD. I Analog BIAS3 input for LCD. I/O O ST Analog Digital I/O. COM0 output for LCD. I/O O ST Analog Digital I/O. COM1 output for LCD. I/O O ST Analog Digital I/O. COM2 output for LCD. I/O O ST Analog Digital I/O. COM3 output for LCD. I/O I/O O ST ST Analog Digital I/O. Capture 2 input/Compare 2 output/PWM2 output. SEG31 output for LCD. Legend: TTL = TTL compatible input CMOS = CMOS compatible input or output ST = Schmitt Trigger input with CMOS levels Analog = Analog input I = Input O = Output P = Power OD = Open-Drain (no P diode to VDD) I2CTM = I2C/SMBus Note 1: Default assignment for CCP2 when the CCP2MX Configuration bit is set. 2: Alternate assignment for CCP2 when the CCP2MX Configuration bit is cleared. 2010 Microchip Technology Inc. DS39770C-page 25 PIC18F85J90 FAMILY TABLE 1-4: PIC18F8XJ90 PINOUT I/O DESCRIPTIONS (CONTINUED) Pin Name Pin Number TQFP Pin Buffer Type Type Description PORTF is a bidirectional I/O port. RF1/AN6/C2OUT/SEG19 RF1 AN6 C2OUT SEG19 23 RF2/AN7/C1OUT/SEG20 RF2 AN7 C1OUT SEG20 18 RF3/AN8/SEG21 RF3 AN8 SEG21 17 RF4/AN9/SEG22 RF4 AN9 SEG22 16 RF5/AN10/CVREF/SEG23 RF5 AN10 CVREF SEG23 15 RF6/AN11/SEG24 RF6 AN11 SEG24 14 RF7/AN5/SS/SEG25 RF7 AN5 SS SEG25 13 I/O I O O ST Analog -- Analog Digital I/O. Analog Input 6. Comparator 2 output. SEG19 output for LCD. I/O I O O ST Analog -- Analog Digital I/O. Analog Input 7. Comparator 1 output. SEG20 output for LCD. I/O I O ST Analog Analog Digital I/O. Analog Input 8. SEG21 output for LCD. I/O I O ST Analog Analog Digital I/O. Analog Input 9. SEG22 output for LCD. I/O I O O ST Analog Analog Analog Digital I/O. Analog Input 10. Comparator reference voltage output. SEG23 output for LCD. I/O I O ST Analog Analog Digital I/O. Analog Input 11. SEG24 output for LCD. I/O O I O ST Analog TTL Analog Digital I/O. Analog Input 5. SPI slave select input. SEG25 output for LCD. Legend: TTL = TTL compatible input CMOS = CMOS compatible input or output ST = Schmitt Trigger input with CMOS levels Analog = Analog input I = Input O = Output P = Power OD = Open-Drain (no P diode to VDD) I2CTM = I2C/SMBus Note 1: Default assignment for CCP2 when the CCP2MX Configuration bit is set. 2: Alternate assignment for CCP2 when the CCP2MX Configuration bit is cleared. DS39770C-page 26 2010 Microchip Technology Inc. PIC18F85J90 FAMILY TABLE 1-4: PIC18F8XJ90 PINOUT I/O DESCRIPTIONS (CONTINUED) Pin Name Pin Number TQFP Pin Buffer Type Type Description PORTG is a bidirectional I/O port. RG0/LCDBIAS0 RG0 LCDBIAS0 5 RG1/TX2/CK2 RG1 TX2 CK2 6 RG2/RX2/DT2/VLCAP1 RG2 RX2 DT2 VLCAP1 7 RG3/VLCAP2 RG3 VLCAP2 8 RG4/SEG26 RG4 SEG26 10 I/O I ST Analog Digital I/O. BIAS0 input for LCD. I/O O I/O ST -- ST Digital I/O. AUSART asynchronous transmit. AUSART synchronous clock (see related RX2/DT2). I/O I I/O I ST ST ST Analog Digital I/O. AUSART asynchronous receive. AUSART synchronous data (see related TX2/CK2). LCD charge pump capacitor input. I/O I ST Analog Digital I/O. LCD charge pump capacitor input. I/O O ST Analog Digital I/O. SEG26 output for LCD. Legend: TTL = TTL compatible input CMOS = CMOS compatible input or output ST = Schmitt Trigger input with CMOS levels Analog = Analog input I = Input O = Output P = Power OD = Open-Drain (no P diode to VDD) I2CTM = I2C/SMBus Note 1: Default assignment for CCP2 when the CCP2MX Configuration bit is set. 2: Alternate assignment for CCP2 when the CCP2MX Configuration bit is cleared. 2010 Microchip Technology Inc. DS39770C-page 27 PIC18F85J90 FAMILY TABLE 1-4: PIC18F8XJ90 PINOUT I/O DESCRIPTIONS (CONTINUED) Pin Name Pin Number TQFP Pin Buffer Type Type Description PORTH is a bidirectional I/O port. RH0/SEG47 RH0 SEG47 79 RH1/SEG46 RH1 SEG46 80 RH2/SEG45 RH2 SEG45 1 RH3/SEG44 RH3 SEG44 2 RH4/SEG40 RH4 SEG40 22 RH5/SEG41 RH5 SEG41 21 RH6/SEG42 RH6 SEG42 20 RH7/SEG43 RH7 SEG43 19 I/O O ST Analog Digital I/O. SEG47 output for LCD. I/O O ST Analog Digital I/O. SEG46 output for LCD. I/O O ST Analog Digital I/O. SEG45 output for LCD. I/O O ST Analog Digital I/O. SEG44 output for LCD. I/O O ST Analog Digital I/O. SEG40 output for LCD. I/O O ST Analog Digital I/O. SEG41 output for LCD. I/O O ST Analog Digital I/O. SEG42 output for LCD. I/O O ST Analog Digital I/O. SEG43 output for LCD. Legend: TTL = TTL compatible input CMOS = CMOS compatible input or output ST = Schmitt Trigger input with CMOS levels Analog = Analog input I = Input O = Output P = Power OD = Open-Drain (no P diode to VDD) I2CTM = I2C/SMBus Note 1: Default assignment for CCP2 when the CCP2MX Configuration bit is set. 2: Alternate assignment for CCP2 when the CCP2MX Configuration bit is cleared. DS39770C-page 28 2010 Microchip Technology Inc. PIC18F85J90 FAMILY TABLE 1-4: PIC18F8XJ90 PINOUT I/O DESCRIPTIONS (CONTINUED) Pin Name Pin Number TQFP Pin Buffer Type Type Description PORTJ is a bidirectional I/O port. RJ0 62 RJ1/SEG33 RJ1 SEG33 61 RJ2/SEG34 RJ2 SEG34 60 RJ3/SEG35 RJ3 SEG35 59 RJ4/SEG39 RJ4 SEG39 39 RJ5/SEG38 RJ5 SEG38 40 RJ6/SEG37 RJ6 SEG37 41 RJ7/SEG36 RJ7 SEG36 42 I/O ST Digital I/O. I/O O ST Analog Digital I/O. SEG33 output for LCD. I/O O ST Analog Digital I/O. SEG34 output for LCD. I/O O ST Analog Digital I/O. SEG35 output for LCD. I/O O ST Analog Digital I/O. SEG39 output for LCD. I/O O ST Analog Digital I/O SEG38 output for LCD. I/O O ST Analog Digital I/O. SEG37 output for LCD. I/O O ST Analog Digital I/O. SEG36 output for LCD. VSS 11, 31, 51, 70 P -- Ground reference for logic and I/O pins. VDD 32, 48, 71 P -- Positive supply for logic and I/O pins. AVSS 26 P -- Ground reference for analog modules. AVDD 25 P -- Positive supply for analog modules. ENVREG 24 I ST VDDCORE/VCAP VDDCORE 12 VCAP P -- P -- Enable for on-chip voltage regulator. Core logic power or external filter capacitor connection. Positive supply for microcontroller core logic (regulator disabled). External filter capacitor connection (regulator enabled). Legend: TTL = TTL compatible input CMOS = CMOS compatible input or output ST = Schmitt Trigger input with CMOS levels Analog = Analog input I = Input O = Output P = Power OD = Open-Drain (no P diode to VDD) I2CTM = I2C/SMBus Note 1: Default assignment for CCP2 when the CCP2MX Configuration bit is set. 2: Alternate assignment for CCP2 when the CCP2MX Configuration bit is cleared. 2010 Microchip Technology Inc. DS39770C-page 29 PIC18F85J90 FAMILY NOTES: DS39770C-page 30 2010 Microchip Technology Inc. PIC18F85J90 FAMILY * All VDD and VSS pins (see Section 2.2 "Power Supply Pins") * All AVDD and AVSS pins, regardless of whether or not the analog device features are used (see Section 2.2 "Power Supply Pins") * MCLR pin (see Section 2.3 "Master Clear (MCLR) Pin") * ENVREG (if implemented) and VCAP/VDDCORE pins (see Section 2.4 "Voltage Regulator Pins (ENVREG and VCAP/VDDCORE)") VDD R2 VCAP/VDDCORE C1 C6(2) VSS VDD VDD VSS C3(2) C5(2) C4(2) Key (all values are recommendations): * PGC/PGD pins used for In-Circuit Serial ProgrammingTM (ICSPTM) and debugging purposes (see Section 2.5 "ICSP Pins") * OSCI and OSCO pins when an external oscillator source is used (see Section 2.6 "External Oscillator Pins") R1: 10 k Note: C7 PIC18FXXJXX C1 through C6: 0.1 F, 20V ceramic * VREF+/VREF- pins are used when external voltage reference for analog modules is implemented (1) (1) ENVREG MCLR These pins must also be connected if they are being used in the end application: Additionally, the following pins may be required: VSS R1 VSS The following pins must always be connected: C2(2) VDD Getting started with the PIC18F85J90 family family of 8-bit microcontrollers requires attention to a minimal set of device pin connections before proceeding with development. RECOMMENDED MINIMUM CONNECTIONS VDD Basic Connection Requirements FIGURE 2-1: AVSS 2.1 GUIDELINES FOR GETTING STARTED WITH PIC18FJ MICROCONTROLLERS AVDD 2.0 C7: 10 F, 6.3V or greater, tantalum or ceramic R2: 100 to 470 Note 1: 2: See Section 2.4 "Voltage Regulator Pins (ENVREG and VCAP/VDDCORE)" for explanation of ENVREG pin connections. The example shown is for a PIC18F device with five VDD/VSS and AVDD/AVSS pairs. Other devices may have more or less pairs; adjust the number of decoupling capacitors appropriately. The AVDD and AVSS pins must always be connected, regardless of whether any of the analog modules are being used. The minimum mandatory connections are shown in Figure 2-1. 2010 Microchip Technology Inc. DS39770C-page 31 PIC18F85J90 FAMILY 2.2 2.2.1 Power Supply Pins DECOUPLING CAPACITORS The use of decoupling capacitors on every pair of power supply pins, such as VDD, VSS, AVDD and AVSS, is required. Consider the following criteria when using decoupling capacitors: * Value and type of capacitor: A 0.1 F (100 nF), 10-20V capacitor is recommended. The capacitor should be a low-ESR device, with a resonance frequency in the range of 200 MHz and higher. Ceramic capacitors are recommended. * Placement on the printed circuit board: The decoupling capacitors should be placed as close to the pins as possible. It is recommended to place the capacitors on the same side of the board as the device. If space is constricted, the capacitor can be placed on another layer on the PCB using a via; however, ensure that the trace length from the pin to the capacitor is no greater than 0.25 inch (6 mm). * Handling high-frequency noise: If the board is experiencing high-frequency noise (upward of tens of MHz), add a second ceramic type capacitor in parallel to the above described decoupling capacitor. The value of the second capacitor can be in the range of 0.01 F to 0.001 F. Place this second capacitor next to each primary decoupling capacitor. In high-speed circuit designs, consider implementing a decade pair of capacitances as close to the power and ground pins as possible (e.g., 0.1 F in parallel with 0.001 F). * Maximizing performance: On the board layout from the power supply circuit, run the power and return traces to the decoupling capacitors first, and then to the device pins. This ensures that the decoupling capacitors are first in the power chain. Equally important is to keep the trace length between the capacitor and the power pins to a minimum, thereby reducing PCB trace inductance. 2.2.2 TANK CAPACITORS On boards with power traces running longer than six inches in length, it is suggested to use a tank capacitor for integrated circuits, including microcontrollers, to supply a local power source. The value of the tank capacitor should be determined based on the trace resistance that connects the power supply source to the device, and the maximum current drawn by the device in the application. In other words, select the tank capacitor so that it meets the acceptable voltage sag at the device. Typical values range from 4.7 F to 47 F. DS39770C-page 32 2.3 Master Clear (MCLR) Pin The MCLR pin provides two specific device functions: Device Reset, and Device Programming and Debugging. If programming and debugging are not required in the end application, a direct connection to VDD may be all that is required. The addition of other components, to help increase the application's resistance to spurious Resets from voltage sags, may be beneficial. A typical configuration is shown in Figure 2-1. Other circuit designs may be implemented, depending on the application's requirements. During programming and debugging, the resistance and capacitance that can be added to the pin must be considered. Device programmers and debuggers drive the MCLR pin. Consequently, specific voltage levels (VIH and VIL) and fast signal transitions must not be adversely affected. Therefore, specific values of R1 and C1 will need to be adjusted based on the application and PCB requirements. For example, it is recommended that the capacitor, C1, be isolated from the MCLR pin during programming and debugging operations by using a jumper (Figure 2-2). The jumper is replaced for normal run-time operations. Any components associated with the MCLR pin should be placed within 0.25 inch (6 mm) of the pin. FIGURE 2-2: EXAMPLE OF MCLR PIN CONNECTIONS VDD R1 R2 JP MCLR PIC18FXXJXX C1 Note 1: R1 10 k is recommended. A suggested starting value is 10 k. Ensure that the MCLR pin VIH and VIL specifications are met. 2: R2 470 will limit any current flowing into MCLR from the external capacitor, C, in the event of MCLR pin breakdown, due to Electrostatic Discharge (ESD) or Electrical Overstress (EOS). Ensure that the MCLR pin VIH and VIL specifications are met. 2010 Microchip Technology Inc. PIC18F85J90 FAMILY 2.4 Voltage Regulator Pins (ENVREG and VCAP/VDDCORE) The on-chip voltage regulator enable pin, ENVREG, must always be connected directly to either a supply voltage or to ground. Tying ENVREG to VDD enables the regulator, while tying it to ground disables the regulator. Refer to Section 23.3 "On-Chip Voltage Regulator" for details on connecting and using the on-chip regulator. When the regulator is enabled, a low-ESR (< 5) capacitor is required on the VCAP/VDDCORE pin to stabilize the voltage regulator output voltage. The VCAP/VDDCORE pin must not be connected to VDD and must use a capacitor of 10 F connected to ground. The type can be ceramic or tantalum. A suitable example is the Murata GRM21BF50J106ZE01 (10 F, 6.3V) or equivalent. Designers may use Figure 2-3 to evaluate ESR equivalence of candidate devices. It is recommended that the trace length not exceed 0.25 inch (6 mm). Refer to Section 26.0 "Electrical Characteristics" for additional information. When the regulator is disabled, the VCAP/VDDCORE pin must be tied to a voltage supply at the VDDCORE level. Refer to Section 26.0 "Electrical Characteristics" for information on VDD and VDDCORE. Note that the "LF" versions of some low pin count PIC18FJ parts (e.g., the PIC18LF45J10) do not have the ENVREG pin. These devices are provided with the voltage regulator permanently disabled; they must always be provided with a supply voltage on the VDDCORE pin. FIGURE 2-3: 2.5 ICSP Pins The PGC and PGD pins are used for In-Circuit Serial ProgrammingTM (ICSPTM) and debugging purposes. It is recommended to keep the trace length between the ICSP connector and the ICSP pins on the device as short as possible. If the ICSP connector is expected to experience an ESD event, a series resistor is recommended, with the value in the range of a few tens of ohms, not to exceed 100. Pull-up resistors, series diodes, and capacitors on the PGC and PGD pins are not recommended as they will interfere with the programmer/debugger communications to the device. If such discrete components are an application requirement, they should be removed from the circuit during programming and debugging. Alternatively, refer to the AC/DC characteristics and timing requirements information in the respective device Flash programming specification for information on capacitive loading limits, and pin input voltage high (VIH) and input low (VIL) requirements. For device emulation, ensure that the "Communication Channel Select" (i.e., PGCx/PGDx pins) programmed into the device matches the physical connections for the ICSP to the Microchip debugger/emulator tool. For more information on available Microchip development tools connection requirements, refer toSection 24.0 "Development Support". FREQUENCY vs. ESR PERFORMANCE FOR SUGGESTED VCAP 10 ESR () 1 0.1 0.01 0.001 0.01 Note: 0.1 1 10 100 Frequency (MHz) 1000 10,000 Data for Murata GRM21BF50J106ZE01 shown. Measurements at 25C, 0V DC bias. 2010 Microchip Technology Inc. DS39770C-page 33 PIC18F85J90 FAMILY 2.6 External Oscillator Pins FIGURE 2-4: Many microcontrollers have options for at least two oscillators: a high-frequency primary oscillator and a low-frequency secondary oscillator (refer to Section 3.0 "Oscillator Configurations" for details). The oscillator circuit should be placed on the same side of the board as the device. Place the oscillator circuit close to the respective oscillator pins with no more than 0.5 inch (12 mm) between the circuit components and the pins. The load capacitors should be placed next to the oscillator itself, on the same side of the board. Use a grounded copper pour around the oscillator circuit to isolate it from surrounding circuits. The grounded copper pour should be routed directly to the MCU ground. Do not run any signal traces or power traces inside the ground pour. Also, if using a two-sided board, avoid any traces on the other side of the board where the crystal is placed. Single-Sided and In-Line Layouts: Copper Pour (tied to ground) For additional information and design guidance on oscillator circuits, please refer to these Microchip Application Notes, available at the corporate web site (www.microchip.com): * AN826, "Crystal Oscillator Basics and Crystal Selection for rfPICTM and PICmicro(R) Devices" * AN849, "Basic PICmicro(R) Oscillator Design" * AN943, "Practical PICmicro(R) Oscillator Analysis and Design" * AN949, "Making Your Oscillator Work" 2.7 Unused I/Os Primary Oscillator Crystal DEVICE PINS Primary Oscillator OSC1 C1 OSC2 GND C2 T1OSO T1OS I Timer1 Oscillator Crystal Layout suggestions are shown in Figure 2-4. In-line packages may be handled with a single-sided layout that completely encompasses the oscillator pins. With fine-pitch packages, it is not always possible to completely surround the pins and components. A suitable solution is to tie the broken guard sections to a mirrored ground layer. In all cases, the guard trace(s) must be returned to ground. In planning the application's routing and I/O assignments, ensure that adjacent port pins and other signals in close proximity to the oscillator are benign (i.e., free of high frequencies, short rise and fall times, and other similar noise). SUGGESTED PLACEMENT OF THE OSCILLATOR CIRCUIT T1 Oscillator: C1 T1 Oscillator: C2 Fine-Pitch (Dual-Sided) Layouts: Top Layer Copper Pour (tied to ground) Bottom Layer Copper Pour (tied to ground) OSCO C2 Oscillator Crystal GND C1 OSCI DEVICE PINS Unused I/O pins should be configured as outputs and driven to a logic low state. Alternatively, connect a 1 k to 10 k resistor to VSS on unused pins and drive the output to logic low. DS39770C-page 34 2010 Microchip Technology Inc. PIC18F85J90 FAMILY 3.0 OSCILLATOR CONFIGURATIONS 3.1 Oscillator Types Five of these are selected by the user by programming the FOSC<2:0> Configuration bits. The sixth mode (INTRC) may be invoked under software control; it can also be configured as the default mode on device Resets. The PIC18F85J90 family of devices can be operated in six different oscillator modes: 1. 2. 3. 4. 5. 6. HS High-Speed Crystal/Resonator HSPLL High-Speed Crystal/Resonator with Software PLL Control EC External Clock with FOSC/4 Output ECPLL External Clock with Software PLL Control INTOSC Internal Fast RC (8 MHz) oscillator INTRC Internal 31 kHz Oscillator FIGURE 3-1: In addition, PIC18F85J90 family devices can switch between different clock sources, either under software control, or automatically under certain conditions. This allows for additional power savings by managing device clock speed in real time without resetting the application. The clock sources for the PIC18F85J90 family of devices are shown in Figure 3-1. PIC18F85J90 FAMILY CLOCK DIAGRAM PIC18F85J90 Family Primary Oscillator HS, EC OSC2 Sleep 4 x PLL OSC1 Secondary Oscillator T1OSCEN Enable Oscillator OSCCON<6:4> 8 MHz 4 MHz Internal Oscillator Block 8 MHz (INTOSC) Postscaler 8 MHz Source 2 MHz 1 MHz 500 kHz 250 kHz 125 kHz 1 31 kHz 0 INTRC Source 2010 Microchip Technology Inc. 31 kHz (INTRC) Internal Oscillator CPU 111 110 IDLEN 101 100 011 MUX OSCCON<6:4> Peripherals MUX T1OSC T1OSO T1OSI HSPLL, ECPLL 010 001 000 Clock Control FOSC<2:0> OSCCON<1:0> Clock Source Option for other modules OSCTUNE<7> WDT, PWRT, FSCM and Two-Speed Start-up DS39770C-page 35 PIC18F85J90 FAMILY 3.2 Control Registers The OSCTUNE register (Register 3-2) controls the tuning and operation of the internal oscillator block. It also implements the PLLEN bits, which control the operation of the Phase Locked Loop (PLL) in Internal Oscillator modes (see Section 3.4.3 "PLL Frequency Multiplier"). The OSCCON register (Register 3-1) controls the main aspects of the device clock's operation. It selects the oscillator type to be used, which of the power-managed modes to invoke and the output frequency of the INTOSC source. It also provides status on the oscillators. REGISTER 3-1: R/W-0 OSCCON: OSCILLATOR CONTROL REGISTER R/W-1 IDLEN IRCF2 (2) R/W-0 (2) IRCF1 R(1) R/W-0 IRCF0 (2) OSTS R-0 IOFS R/W-0 SCS1 (4) R/W-0 SCS0(4) bit 7 bit 0 Legend: R = Readable bit W = Writable bit U = Unimplemented bit, read as `0' -n = Value at POR `1' = Bit is set `0' = Bit is cleared x = Bit is unknown bit 7 IDLEN: Idle Enable bit 1 = Device enters an Idle mode when a SLEEP instruction is executed 0 = Device enters Sleep mode when a SLEEP instruction is executed bit 6-4 IRCF<2:0>: INTOSC Source Frequency Select bits(2) 111 = 8 MHz (INTOSC drives clock directly) 110 = 4 MHz 101 = 2 MHz 100 = 1 MHz (default) 011 = 500 kHz 010 = 250 kHz 001 = 125 kHz 000 = 31 kHz (from either INTOSC/256 or INTRC)(3) bit 3 OSTS: Oscillator Start-up Time-out Status bit(1) 1 = Oscillator Start-up Timer (OST) time-out has expired; primary oscillator is running 0 = Oscillator Start-up Timer (OST) time-out is running; primary oscillator is not ready bit 2 IOFS: INTOSC Frequency Stable bit 1 = Fast RC oscillator frequency is stable 0 = Fast RC oscillator frequency is not stable bit 1-0 SCS<1:0:> System Clock Select bits(4) 11 = Internal oscillator block 10 = Primary oscillator 01 = Timer1 oscillator When FOSC2 = 1: 00 = Primary oscillator When FOSC2 = 0: 00 = Internal oscillator Note 1: 2: 3: 4: Reset state depends on state of the IESO Configuration bit. Modifying these bits will cause an immediate clock frequency switch if the internal oscillator is providing the device clocks. Source selected by the INTSRC bit (OSCTUNE<7>), see text. Modifying these bits will cause an immediate clock source switch. DS39770C-page 36 2010 Microchip Technology Inc. PIC18F85J90 FAMILY REGISTER 3-2: R/W-0 INTSRC OSCTUNE: OSCILLATOR TUNING REGISTER R/W-0 PLLEN (1) R/W-0 R/W-0 R/W-0 R/W-0 R/W-0 R/W-0 TUN5 TUN4 TUN3 TUN2 TUN1 TUN0 bit 7 bit 0 Legend: R = Readable bit W = Writable bit U = Unimplemented bit, read as `0' -n = Value at POR `1' = Bit is set `0' = Bit is cleared x = Bit is unknown bit 7 INTSRC: Internal Oscillator Low-Frequency Source Select bit 1 = 31.25 kHz device clock derived from 8 MHz INTOSC source (divide-by-256 enabled) 0 = 31 kHz device clock derived from INTRC 31 kHz oscillator bit 6 PLLEN: Frequency Multiplier PLL Enable bit(1) 1 = PLL enabled 0 = PLL disabled bit 5-0 TUN<5:0>: Fast RC Oscillator (INTOSC) Frequency Tuning bits 011111 = Maximum frequency * * * * 000001 000000 = Center frequency. Fast RC oscillator is running at the calibrated frequency. 111111 * * * * 100000 = Minimum frequency Note 1: 3.3 Available only for ECPLL and HSPLL oscillator configurations; otherwise, this bit is unavailable and reads as `0'. Clock Sources and Oscillator Switching Essentially, PIC18F85J90 family devices have three independent clock sources: * Primary oscillators * Secondary oscillators * Internal oscillator The primary oscillators can be thought of as the main device oscillators. These are any external oscillators connected to the OSC1 and OSC2 pins, and include the External Crystal and Resonator modes and the External Clock modes. In some circumstances, the internal oscillator block may be considered a primary oscillator. The particular mode is defined by the FOSC Configuration bits. The details of these modes are covered in Section 3.4 "External Oscillator Modes". The secondary oscillators are external clock sources that are not connected to the OSC1 or OSC2 pins. These sources may continue to operate even after the controller is placed in a power-managed mode. 2010 Microchip Technology Inc. PIC18F85J90 family devices offer the Timer1 oscillator as a secondary oscillator source. This oscillator, in all power-managed modes, is often the time base for functions such as a Real-Time Clock. The Timer1 oscillator is discussed in greater detail in Section 12.3 "Timer1 Oscillator" In addition to being a primary clock source in some circumstances, the internal oscillator is available as a power-managed mode clock source. The INTRC source is also used as the clock source for several special features, such as the WDT and Fail-Safe Clock Monitor. The internal oscillator block is discussed in more detail in Section 3.5 "Internal Oscillator Block". The PIC18F85J90 family includes features that allow the device clock source to be switched from the main oscillator, chosen by device configuration, to one of the alternate clock sources. When an alternate clock source is enabled, various power-managed operating modes are available. DS39770C-page 37 PIC18F85J90 FAMILY 3.3.1 CLOCK SOURCE SELECTION The System Clock Select bits, SCS<1:0> (OSCCON<1:0>), select the clock source. The available clock sources are the primary clock defined by the FOSC<1:0> Configuration bits, the secondary clock (Timer1 oscillator) and the internal oscillator. The clock source changes after one or more of the bits are written to, following a brief clock transition interval. The OSTS (OSCCON<3>) and T1RUN (T1CON<6>) bits indicate which clock source is currently providing the device clock. The OSTS bit indicates that the Oscillator Start-up Timer (OST) has timed out and the primary clock is providing the device clock in primary clock modes. The T1RUN bit indicates when the Timer1 oscillator is providing the device clock in secondary clock modes. In power-managed modes, only one of these bits will be set at any time. If neither of these bits are set, the INTRC is providing the clock, or the internal oscillator has just started and is not yet stable. The IDLEN bit determines if the device goes into Sleep mode or one of the Idle modes when the SLEEP instruction is executed. The use of the flag and control bits in the OSCCON register is discussed in more detail in Section 4.0 "Power-Managed Modes". Note 1: The Timer1 oscillator must be enabled to select the secondary clock source. The Timer1 oscillator is enabled by setting the T1OSCEN bit in the Timer1 Control register (T1CON<3>). If the Timer1 oscillator is not enabled, then any attempt to select a secondary clock source when executing a SLEEP instruction will be ignored. 2: It is recommended that the Timer1 oscillator be operating and stable before executing the SLEEP instruction or a very long delay may occur while the Timer1 oscillator starts. 3.3.1.1 System Clock Selection and the FOSC2 Configuration Bit The SCS bits are cleared on all forms of Reset. In the device's default configuration, this means the primary oscillator defined by FOSC<1:0> (that is, one of the HS or EC modes) is used as the primary clock source on device Resets. The default clock configuration on Reset can be changed with the FOSC2 Configuration bit. This bit determines whether the external or internal oscillator will be the default clock source on subsequent device Resets. By extension, it also has the effect of determining the clock source selected when SCS<1:0> are in their Reset state (= 00). When FOSC2 = 1 (default), the oscillator source defined by FOSC<1:0> is selected whenever SCS<1:0> = 00. When FOSC2 = 0, the internal oscillator block is selected whenever SCS<1:2> = 00. In those cases when the internal oscillator block is the default clock on Reset, the Fast RC oscillator (INTOSC) will be used as the device clock source. It will initially start at 1 MHz, the postscaler selection that corresponds to the Reset value of the IRCF<2:0> bits (`100'). Regardless of the setting of FOSC2, INTRC will always be enabled on device power-up. It serves as the clock source until the device has loaded its configuration values from memory. It is at this point that the FOSC Configuration bits are read and the oscillator selection of the operational mode is made. Note that either the primary clock or the internal oscillator will have two bit setting options for the possible values of SCS<1:0>, at any given time, depending on the setting of FOSC2. 3.3.2 OSCILLATOR TRANSITIONS PIC18F85J90 family devices contain circuitry to prevent clock "glitches" when switching between clock sources. A short pause in the device clock occurs during the clock switch. The length of this pause is the sum of two cycles of the old clock source and three to four cycles of the new clock source. This formula assumes that the new clock source is stable. Clock transitions are discussed in greater detail in Section 4.1.2 "Entering Power-Managed Modes". DS39770C-page 38 2010 Microchip Technology Inc. PIC18F85J90 FAMILY 3.4 External Oscillator Modes 3.4.1 TABLE 3-2: CRYSTAL OSCILLATOR/CERAMIC RESONATORS (HS MODES) In HS or HSPLL Oscillator modes, a crystal or ceramic resonator is connected to the OSC1 and OSC2 pins to establish oscillation. Figure 3-2 shows the pin connections. The oscillator design requires the use of a parallel resonant crystal. Note: Use of a series resonant crystal may give a frequency out of the crystal manufacturer's specifications. TABLE 3-1: CAPACITOR SELECTION FOR CERAMIC RESONATORS Typical Capacitor Values Used: Mode Freq. OSC1 OSC2 HS 8.0 MHz 16.0 MHz 27 pF 22 pF 27 pF 22 pF Capacitor values are for design guidance only. Different capacitor values may be required to produce acceptable oscillator operation. The user should test the performance of the oscillator over the expected VDD and temperature range for the application. Refer to the following application notes for oscillator-specific information: * AN588, "PIC(R) Microcontroller Oscillator Design Guide" * AN826, "Crystal Oscillator Basics and Crystal Selection for rfPIC(R) and PIC(R) Devices" * AN849, "Basic PIC(R) Oscillator Design" * AN943, "Practical PIC(R) Oscillator Analysis and Design" * AN949, "Making Your Oscillator Work" See the notes following Table 3-2 for additional information. CAPACITOR SELECTION FOR CRYSTAL OSCILLATOR Typical Capacitor Values Tested: Crystal Freq. Osc Type HS C1 C2 4 MHz 27 pF 27 pF 8 MHz 22 pF 22 pF 20 MHz 15 pF 15 pF Capacitor values are for design guidance only. Different capacitor values may be required to produce acceptable oscillator operation. The user should test the performance of the oscillator over the expected VDD and temperature range for the application. Refer to the Microchip application notes cited in Table 3-1 for oscillator-specific information. Also see the notes following this table for additional information. Note 1: Higher capacitance increases the stability of oscillator but also increases the start-up time. 2: Since each resonator/crystal has its own characteristics, the user should consult the resonator/crystal manufacturer for appropriate values of external components. 3: Rs may be required to avoid overdriving crystals with low drive level specification. 4: Always verify oscillator performance over the VDD and temperature range that is expected for the application. FIGURE 3-2: CRYSTAL/CERAMIC RESONATOR OPERATION (HS OR HSPLL CONFIGURATION) C1(1) OSC1 XTAL RF(3) OSC2 C2(1) 2010 Microchip Technology Inc. To Internal Logic RS(2) Sleep PIC18F85J90 Note 1: See Table 3-1 and Table 3-2 for initial values of C1 and C2. 2: A series resistor (RS) may be required for AT strip cut crystals. 3: RF varies with the oscillator mode chosen. DS39770C-page 39 PIC18F85J90 FAMILY EXTERNAL CLOCK INPUT (EC MODES) The EC and ECPLL Oscillator modes require an external clock source to be connected to the OSC1 pin. There is no oscillator start-up time required after a Power-on Reset or after an exit from Sleep mode. In the EC Oscillator mode, the oscillator frequency divided by 4 is available on the OSC2 pin. This signal may be used for test purposes or to synchronize other logic. Figure 3-3 shows the pin connections for the EC Oscillator mode. FIGURE 3-3: EXTERNAL CLOCK INPUT OPERATION (EC CONFIGURATION) OSC1/CLKI Clock from Ext. System PIC18F85J90 FOSC/4 or RA6 OSC2/CLKO 3.4.3 PLL FREQUENCY MULTIPLIER A Phase Locked Loop (PLL) circuit is provided as an option for users who want to use a lower frequency oscillator circuit, or to clock the device up to its highest rated frequency from a crystal oscillator. This may be useful for customers who are concerned with EMI due to high-frequency crystals, or users who require higher clock speeds from an internal oscillator. For these reasons, the HSPLL and ECPLL modes are available. The HSPLL and ECPLL modes provide the ability to selectively run the device at 4 times the external oscillating source to produce frequencies up to 40 MHz. The PLL is enabled by programming the FOSC<2:0> Configuration bits (CONFIG2L<2:0>) to either `110' (for ECPLL) or `100' (for HSPLL). In addition, the PLLEN bit (OSCTUNE<6>) must also be set. Clearing PLLEN disables the PLL, regardless of the chosen oscillator configuration. It also allows additional flexibility for controlling the application's clock speed in software. FIGURE 3-5: HSPLL or ECPLL (CONFIG2L) PLL Enable (OSCTUNE) An external clock source may also be connected to the OSC1 pin in the HS mode, as shown in Figure 3-4. In this configuration, the divide-by-4 output on OSC2 is not available. OSC2 FIGURE 3-4: HS or EC OSC1 Mode EXTERNAL CLOCK INPUT OPERATION (HS OSC CONFIGURATION) PLL BLOCK DIAGRAM FIN FOUT Phase Comparator Loop Filter OSC1 Clock from Ext. System PIC18F85J90 Open DS39770C-page 40 OSC2 (HS Mode) 4 VCO MUX 3.4.2 SYSCLK 2010 Microchip Technology Inc. PIC18F85J90 FAMILY 3.5 Internal Oscillator Block The PIC18F85J90 family of devices includes an internal oscillator block which generates two different clock signals; either can be used as the microcontroller's clock source. This may eliminate the need for an external oscillator circuit on the OSC1 and/or OSC2 pins. The main output is the Fast RC oscillator, or INTOSC, an 8 MHz clock source which can be used to directly drive the device clock. It also drives a postscaler, which can provide a range of clock frequencies from 31 kHz to 4 MHz. INTOSC is enabled when a clock frequency from 125 kHz to 8 MHz is selected. The INTOSC output can also be enabled when 31 kHz is selected, depending on the INTSRC bit (OSCTUNE<7>). The other clock source is the Internal RC oscillator (INTRC), which provides a nominal 31 kHz output. INTRC is enabled if it is selected as the device clock source. It is also enabled automatically when any of the following are enabled: * Power-up Timer * Fail-Safe Clock Monitor * Watchdog Timer * Two-Speed Start-up These features are discussed in greater detail in Section 23.0 "Special Features of the CPU". The clock source frequency (INTOSC direct, INTOSC with postscaler or INTRC direct) is selected by configuring the IRCF bits of the OSCCON register. The default frequency on device Resets is 1 MHz. 3.5.1 OSC1 AND OSC2 PIN CONFIGURATION Whenever the internal oscillator is configured as the default clock source (FOSC2 = 0), the OSC1 and OSC2 pins are reconfigured automatically as port pins, RA6 and RA7. In this mode, they function as general digital I/O. All oscillator functions on the pins are disabled. 3.5.2 INTERNAL OSCILLATOR OUTPUT FREQUENCY AND TUNING The internal oscillator block is calibrated at the factory to produce an INTOSC output frequency of 8 MHz. It can be adjusted in the user's application by writing to TUN<5:0> (OSCTUNE<5:0>) in the OSCTUNE register (Register 3-2). When the OSCTUNE register is modified, the INTOSC frequency will begin shifting to the new frequency. The oscillator will stabilize within 1 ms. Code execution continues during this shift. There is no indication that the shift has occurred. The INTRC oscillator operates independently of the INTOSC source. Any changes in INTOSC across voltage and temperature are not necessarily reflected by changes in INTRC or vice versa. The frequency of INTRC is not affected by OSCTUNE. 2010 Microchip Technology Inc. 3.5.3 INTOSC FREQUENCY DRIFT The INTOSC frequency may drift as VDD or temperature changes, and can affect the controller operation in a variety of ways. It is possible to adjust the INTOSC frequency by modifying the value in the OSCTUNE register. This will have no effect on the INTRC clock source frequency. Tuning INTOSC requires knowing when to make the adjustment, in which direction it should be made and in some cases, how large a change is needed. Three compensation techniques are shown here. 3.5.3.1 Compensating with the EUSART An adjustment may be required when the EUSART begins to generate framing errors or receives data with errors while in Asynchronous mode. Framing errors indicate that the device clock frequency is too high. To adjust for this, decrement the value in OSCTUNE to reduce the clock frequency. On the other hand, errors in data may suggest that the clock speed is too low. To compensate, increment OSCTUNE to increase the clock frequency. 3.5.3.2 Compensating with the Timers This technique compares device clock speed to some reference clock. Two timers may be used; one timer is clocked by the peripheral clock, while the other is clocked by a fixed reference source, such as the Timer1 oscillator. Both timers are cleared, but the timer clocked by the reference generates interrupts. When an interrupt occurs, the internally clocked timer is read and both timers are cleared. If the internally clocked timer value is much greater than expected, then the internal oscillator block is running too fast. To adjust for this, decrement the OSCTUNE register. 3.5.3.3 Compensating with the CCP Module in Capture Mode A CCP module can use free-running Timer1 (or Timer3), clocked by the internal oscillator block and an external event with a known period (i.e., AC power frequency). The time of the first event is captured in the CCPRxH:CCPRxL registers and is recorded for use later. When the second event causes a capture, the time of the first event is subtracted from the time of the second event. Since the period of the external event is known, the time difference between events can be calculated. If the measured time is much greater than the calculated time, the internal oscillator block is running too fast. To compensate, decrement the OSCTUNE register. If the measured time is much less than the calculated time, the internal oscillator block is running too slow. To compensate, increment the OSCTUNE register. DS39770C-page 41 PIC18F85J90 FAMILY 3.6 Effects of Power-Managed Modes on the Various Clock Sources When PRI_IDLE mode is selected, the designated primary oscillator continues to run without interruption. For all other power-managed modes, the oscillator using the OSC1 pin is disabled. The OSC1 pin (and OSC2 pin if used by the oscillator) will stop oscillating. In secondary clock modes (SEC_RUN and SEC_IDLE), the Timer1 oscillator is operating and providing the device clock. The Timer1 oscillator may also run in all power-managed modes if required to clock Timer1 or Timer3. In RC_RUN and RC_IDLE modes, the internal oscillator provides the device clock source. The 31 kHz INTRC output can be used directly to provide the clock and may be enabled to support various special features, regardless of the power-managed mode (see Section 23.2 "Watchdog Timer (WDT)" through Section 23.5 "Fail-Safe Clock Monitor" for more information on WDT, Fail-Safe Clock Monitor and Two-Speed Start-up). If the Sleep mode is selected, all clock sources are stopped. Since all the transistor switching currents have been stopped, Sleep mode achieves the lowest current consumption of the device (only leakage currents). Enabling any on-chip feature that will operate during Sleep will increase the current consumed during Sleep. The INTRC is required to support WDT operation. The TABLE 3-3: Timer1 oscillator may be operating to support a RealTime Clock. Other features may be operating that do not require a device clock source (i.e., MSSP slave, PSP, INTx pins and others). Peripherals that may add significant current consumption are listed in Section 26.2 "DC Characteristics: Power-Down and Supply Current". 3.7 Power-up Delays Power-up delays are controlled by two timers, so that no external Reset circuitry is required for most applications. The delays ensure that the device is kept in Reset until the device power supply is stable under normal circumstances and the primary clock is operating and stable. For additional information on power-up delays, see Section 5.6 "Power-up Timer (PWRT)". The first timer is the Power-up Timer (PWRT), which provides a fixed delay on power-up (parameter 33, Table 26-11). It is always enabled. The second timer is the Oscillator Start-up Timer (OST), intended to keep the chip in Reset until the crystal oscillator is stable (HS modes). The OST does this by counting 1024 oscillator cycles before allowing the oscillator to clock the device. There is a delay of interval TCSD (parameter 38, Table 26-11), following POR, while the controller becomes ready to execute instructions. OSC1 AND OSC2 PIN STATES IN SLEEP MODE Oscillator Mode OSC1 Pin OSC2 Pin EC, ECPLL Floating, pulled by external clock At logic low (clock/4 output) HS, HSPLL Feedback inverter disabled at quiescent voltage level Feedback inverter disabled at quiescent voltage level INTOSC I/O pin, RA6, direction controlled by TRISA<6> I/O pin, RA7, direction controlled by TRISA<7> Note: See Table 5-2 in Section 5.0 "Reset" for time-outs due to Sleep and MCLR Reset. DS39770C-page 42 2010 Microchip Technology Inc. PIC18F85J90 FAMILY 4.0 POWER-MANAGED MODES 4.1.1 CLOCK SOURCES The PIC18F85J90 family devices provide the ability to manage power consumption by simply managing clocking to the CPU and the peripherals. In general, a lower clock frequency and a reduction in the number of circuits being clocked constitutes lower consumed power. For the sake of managing power in an application, there are three primary modes of operation: The SCS<1:0> bits allow the selection of one of three clock sources for power-managed modes. They are: * Run mode * Idle mode * Sleep mode 4.1.2 These modes define which portions of the device are clocked and at what speed. The Run and Idle modes may use any of the three available clock sources (primary, secondary or internal oscillator block); the Sleep mode does not use a clock source. The power-managed modes include several power-saving features offered on previous PIC(R) devices. One is the clock switching feature, offered in other PIC18 devices, allowing the controller to use the Timer1 oscillator in place of the primary oscillator. Also included is the Sleep mode, offered by all PIC devices, where all device clocks are stopped. 4.1 Selecting Power-Managed Modes Selecting a power-managed mode requires two decisions: if the CPU is to be clocked or not and which clock source is to be used. The IDLEN bit (OSCCON<7>) controls CPU clocking, while the SCS<1:0> bits (OSCCON<1:0>) select the clock source. The individual modes, bit settings, clock sources and affected modules are summarized in Table 4-1. TABLE 4-1: ENTERING POWER-MANAGED MODES Switching from one power-managed mode to another begins by loading the OSCCON register. The SCS<1:0> bits select the clock source and determine which Run or Idle mode is to be used. Changing these bits causes an immediate switch to the new clock source, assuming that it is running. The switch may also be subject to clock transition delays. These are discussed in Section 4.1.3 "Clock Transitions and Status Indicators" and subsequent sections. Entry to the power-managed Idle or Sleep modes is triggered by the execution of a SLEEP instruction. The actual mode that results depends on the status of the IDLEN bit. Depending on the current mode and the mode being switched to, a change to a power-managed mode does not always require setting all of these bits. Many transitions may be done by changing the oscillator select bits, or changing the IDLEN bit, prior to issuing a SLEEP instruction. If the IDLEN bit is already configured correctly, it may only be necessary to perform a SLEEP instruction to switch to the desired mode. POWER-MANAGED MODES OSCCON bits Mode * the primary clock, as defined by the FOSC<2:0> Configuration bits * the secondary clock (Timer1 oscillator) * the internal oscillator (1) IDLEN<7> Module Clocking Available Clock and Oscillator Source SCS<1:0> CPU Peripherals 0 N/A Off Off PRI_RUN N/A 10 Clocked Clocked Primary - HS, EC, HSPLL, ECPLL; this is the normal full-power execution mode SEC_RUN N/A 01 Clocked Clocked Secondary - Timer1 Oscillator RC_RUN N/A 11 Clocked Clocked Internal Oscillator PRI_IDLE 1 10 Off Clocked Primary - HS, EC, HSPLL, ECPLL SEC_IDLE 1 01 Off Clocked Secondary - Timer1 Oscillator RC_IDLE 1 11 Off Clocked Internal Oscillator Sleep Note 1: None - All clocks are disabled IDLEN reflects its value when the SLEEP instruction is executed. 2010 Microchip Technology Inc. DS39770C-page 43 PIC18F85J90 FAMILY 4.1.3 CLOCK TRANSITIONS AND STATUS INDICATORS The length of the transition between clock sources is the sum of two cycles of the old clock source and three to four cycles of the new clock source. This formula assumes that the new clock source is stable. Two bits indicate the current clock source and its status: OSTS (OSCCON<3>) and T1RUN (T1CON<6>). In general, only one of these bits will be set while in a given power-managed mode. When the OSTS bit is set, the primary clock is providing the device clock. When the T1RUN bit is set, the Timer1 oscillator is providing the clock. If neither of these bits is set, INTRC is clocking the device. Note: 4.1.4 Executing a SLEEP instruction does not necessarily place the device into Sleep mode. It acts as the trigger to place the controller into either the Sleep mode, or one of the Idle modes, depending on the setting of the IDLEN bit. MULTIPLE SLEEP COMMANDS The power-managed mode that is invoked with the SLEEP instruction is determined by the setting of the IDLEN bit at the time the instruction is executed. If another SLEEP instruction is executed, the device will enter the power-managed mode specified by IDLEN at that time. If IDLEN has changed, the device will enter the new power-managed mode specified by the new setting. DS39770C-page 44 4.2 Run Modes In the Run modes, clocks to both the core and peripherals are active. The difference between these modes is the clock source. 4.2.1 PRI_RUN MODE The PRI_RUN mode is the normal, full-power execution mode of the microcontroller. This is also the default mode upon a device Reset unless Two-Speed Start-up is enabled (see Section 23.4 "Two-Speed Start-up" for details). In this mode, the OSTS bit is set (see Section 3.2 "Control Registers"). 4.2.2 SEC_RUN MODE The SEC_RUN mode is the compatible mode to the "clock switching" feature offered in other PIC18 devices. In this mode, the CPU and peripherals are clocked from the Timer1 oscillator. This gives users the option of lower power consumption while still using a high-accuracy clock source. SEC_RUN mode is entered by setting the SCS<1:0> bits to `01'. The device clock source is switched to the Timer1 oscillator (see Figure 4-1), the primary oscillator is shut down, the T1RUN bit (T1CON<6>) is set and the OSTS bit is cleared. 2010 Microchip Technology Inc. PIC18F85J90 FAMILY Note: On transitions from SEC_RUN mode to PRI_RUN mode, the peripherals and CPU continue to be clocked from the Timer1 oscillator while the primary clock is started. When the primary clock becomes ready, a clock switch back to the primary clock occurs (see Figure 4-2). When the clock switch is complete, the T1RUN bit is cleared, the OSTS bit is set and the primary clock is providing the clock. The IDLEN and SCS bits are not affected by the wake-up; the Timer1 oscillator continues to run. The Timer1 oscillator should already be running prior to entering SEC_RUN mode. If the T1OSCEN bit is not set when the SCS<1:0> bits are set to `01', entry to SEC_RUN mode will not occur. If the Timer1 oscillator is enabled, but not yet running, device clocks will be delayed until the oscillator has started. In such situations, initial oscillator operation is far from stable and unpredictable operation may result. FIGURE 4-1: TRANSITION TIMING FOR ENTRY TO SEC_RUN MODE Q1 Q2 Q3 Q4 Q1 Q2 1 T1OSI 2 3 n-1 Q3 Q4 Q1 Q2 Q3 n Clock Transition OSC1 CPU Clock Peripheral Clock Program Counter FIGURE 4-2: PC PC + 2 PC + 4 TRANSITION TIMING FROM SEC_RUN MODE TO PRI_RUN MODE (HSPLL) Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 T1OSI OSC1 TOST(1) TPLL(1) 1 PLL Clock Output 2 n-1 n Clock Transition CPU Clock Peripheral Clock Program Counter PC + 2 PC SCS<1:0> bits Changed PC + 4 OSTS bit Set Note 1: TOST = 1024 TOSC; TPLL = 2 ms (approx). These intervals are not shown to scale. 2010 Microchip Technology Inc. DS39770C-page 45 PIC18F85J90 FAMILY 4.2.3 RC_RUN MODE On transitions from RC_RUN mode to PRI_RUN mode, the device continues to be clocked from the INTRC while the primary clock is started. When the primary clock becomes ready, a clock switch to the primary clock occurs (see Figure 4-4). When the clock switch is complete, the OSTS bit is set and the primary clock is providing the device clock. The IDLEN and SCS bits are not affected by the switch. The INTRC source will continue to run if either the WDT or the Fail-Safe Clock Monitor is enabled. In RC_RUN mode, the CPU and peripherals are clocked from the internal oscillator; the primary clock is shut down. This mode provides the best power conservation of all the Run modes while still executing code. It works well for user applications which are not highly timing-sensitive or do not require high-speed clocks at all times. This mode is entered by setting the SCS bits to `11'. When the clock source is switched to the INTRC (see Figure 4-3), the primary oscillator is shut down and the OSTS bit is cleared. FIGURE 4-3: TRANSITION TIMING TO RC_RUN MODE Q1 Q2 Q3 Q4 Q1 Q2 1 INTRC 2 3 n-1 Q3 Q4 Q1 Q2 Q3 n Clock Transition OSC1 CPU Clock Peripheral Clock Program Counter FIGURE 4-4: PC PC + 2 PC + 4 TRANSITION TIMING FROM RC_RUN MODE TO PRI_RUN MODE Q1 Q2 Q3 Q4 Q2 Q3 Q4 Q1 Q2 Q3 Q1 INTRC OSC1 TOST(1) TPLL(1) 1 PLL Clock Output 2 n-1 n Clock Transition CPU Clock Peripheral Clock Program Counter PC + 2 PC SCS<1:0> bits Changed PC + 4 OSTS bit Set Note 1: TOST = 1024 TOSC; TPLL = 2 ms (approx). These intervals are not shown to scale. DS39770C-page 46 2010 Microchip Technology Inc. PIC18F85J90 FAMILY 4.3 Sleep Mode 4.4 The power-managed Sleep mode is identical to the legacy Sleep mode offered in all other PIC devices. It is entered by clearing the IDLEN bit (the default state on device Reset) and executing the SLEEP instruction. This shuts down the selected oscillator (Figure 4-5). All clock source status bits are cleared. Idle Modes The Idle modes allow the controller's CPU to be selectively shut down while the peripherals continue to operate. Selecting a particular Idle mode allows users to further manage power consumption. If the IDLEN bit is set to a `1' when a SLEEP instruction is executed, the peripherals will be clocked from the clock source selected using the SCS<1:0> bits; however, the CPU will not be clocked. The clock source status bits are not affected. Setting IDLEN and executing a SLEEP instruction provides a quick method of switching from a given Run mode to its corresponding Idle mode. Entering the Sleep mode from any other mode does not require a clock switch. This is because no clocks are needed once the controller has entered Sleep. If the WDT is selected, the INTRC source will continue to operate. If the Timer1 oscillator is enabled, it will also continue to run. If the WDT is selected, the INTRC source will continue to operate. If the Timer1 oscillator is enabled, it will also continue to run. When a wake event occurs in Sleep mode (by interrupt, Reset or WDT time-out), the device will not be clocked until the clock source selected by the SCS<1:0> bits becomes ready (see Figure 4-6), or it will be clocked from the internal oscillator if either the Two-Speed Start-up or the Fail-Safe Clock Monitor are enabled (see Section 23.0 "Special Features of the CPU"). In either case, the OSTS bit is set when the primary clock is providing the device clocks. The IDLEN and SCS bits are not affected by the wake-up. Since the CPU is not executing instructions, the only exits from any of the Idle modes are by interrupt, WDT time-out or a Reset. When a wake event occurs, CPU execution is delayed by an interval of TCSD (parameter 38, Table 26-11) while it becomes ready to execute code. When the CPU begins executing code, it resumes with the same clock source for the current Idle mode. For example, when waking from RC_IDLE mode, the internal oscillator block will clock the CPU and peripherals (in other words, RC_RUN mode). The IDLEN and SCS bits are not affected by the wake-up. While in any Idle mode or the Sleep mode, a WDT time-out will result in a WDT wake-up to the Run mode currently specified by the SCS<1:0> bits. FIGURE 4-5: TRANSITION TIMING FOR ENTRY TO SLEEP MODE Q1 Q2 Q3 Q4 Q1 OSC1 CPU Clock Peripheral Clock Sleep Program Counter PC FIGURE 4-6: PC + 2 TRANSITION TIMING FOR WAKE FROM SLEEP (HSPLL) Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 OSC1 TOST(1) PLL Clock Output TPLL(1) CPU Clock Peripheral Clock Program Counter PC Wake Event PC + 2 PC + 4 PC + 6 OSTS bit Set Note 1: TOST = 1024 TOSC; TPLL = 2 ms (approx). These intervals are not shown to scale. 2010 Microchip Technology Inc. DS39770C-page 47 PIC18F85J90 FAMILY 4.4.1 PRI_IDLE MODE 4.4.2 This mode is unique among the three low-power Idle modes, in that it does not disable the primary device clock. For timing-sensitive applications, this allows for the fastest resumption of device operation with its more accurate primary clock source, since the clock source does not have to "warm up" or transition from another oscillator. PRI_IDLE mode is entered from PRI_RUN mode by setting the IDLEN bit and executing a SLEEP instruction. If the device is in another Run mode, set IDLEN first, then set the SCS bits to `10' and execute SLEEP. Although the CPU is disabled, the peripherals continue to be clocked from the primary clock source specified by the FOSC<1:0> Configuration bits. The OSTS bit remains set (see Figure 4-7). In SEC_IDLE mode, the CPU is disabled but the peripherals continue to be clocked from the Timer1 oscillator. This mode is entered from SEC_RUN by setting the IDLEN bit and executing a SLEEP instruction. If the device is in another Run mode, set IDLEN first, then set SCS<1:0> to `01' and execute SLEEP. When the clock source is switched to the Timer1 oscillator, the primary oscillator is shut down, the OSTS bit is cleared and the T1RUN bit is set. When a wake event occurs, the peripherals continue to be clocked from the Timer1 oscillator. After an interval of TCSD following the wake event, the CPU begins executing code being clocked by the Timer1 oscillator. The IDLEN and SCS bits are not affected by the wake-up; the Timer1 oscillator continues to run (see Figure 4-8). When a wake event occurs, the CPU is clocked from the primary clock source. A delay of interval TCSD is required between the wake event and when code execution starts. This is required to allow the CPU to become ready to execute instructions. After the wake-up, the OSTS bit remains set. The IDLEN and SCS bits are not affected by the wake-up (see Figure 4-8). FIGURE 4-7: SEC_IDLE MODE Note: The Timer1 oscillator should already be running prior to entering SEC_IDLE mode. If the T1OSCEN bit is not set when the SLEEP instruction is executed, the SLEEP instruction will be ignored and entry to SEC_IDLE mode will not occur. If the Timer1 oscillator is enabled, but not yet running, peripheral clocks will be delayed until the oscillator has started. In such situations, initial oscillator operation is far from stable and unpredictable operation may result. TRANSITION TIMING FOR ENTRY TO IDLE MODE Q1 Q4 Q3 Q2 Q1 OSC1 CPU Clock Peripheral Clock Program Counter FIGURE 4-8: PC PC + 2 TRANSITION TIMING FOR WAKE FROM IDLE TO RUN MODE Q1 Q2 Q3 Q4 OSC1 TCSD CPU Clock Peripheral Clock Program Counter PC Wake Event DS39770C-page 48 2010 Microchip Technology Inc. PIC18F85J90 FAMILY 4.4.3 RC_IDLE MODE In RC_IDLE mode, the CPU is disabled but the peripherals continue to be clocked from the internal oscillator. This mode allows for controllable power conservation during Idle periods. From RC_RUN, this mode is entered by setting the IDLEN bit and executing a SLEEP instruction. If the device is in another Run mode, first set IDLEN, then clear the SCS bits and execute SLEEP. When the clock source is switched to the INTRC, the primary oscillator is shut down and the OSTS bit is cleared. When a wake event occurs, the peripherals continue to be clocked from the INTOSC. After a delay of TCSD, following the wake event, the CPU begins executing code being clocked by the INTOSC. The IDLEN and SCS bits are not affected by the wake-up. The INTOSC source will continue to run if either the WDT or the Fail-Safe Clock Monitor is enabled. 4.5 Exiting Idle and Sleep Modes An exit from Sleep mode, or any of the Idle modes, is triggered by an interrupt, a Reset or a WDT time-out. This section discusses the triggers that cause exits from power-managed modes. The clocking subsystem actions are discussed in each of the power-managed mode sections (see Section 4.2 "Run Modes", Section 4.3 "Sleep Mode" and Section 4.4 "Idle Modes"). 4.5.1 EXIT BY INTERRUPT Any of the available interrupt sources can cause the device to exit from an Idle mode, or the Sleep mode, to a Run mode. To enable this functionality, an interrupt source must be enabled by setting its enable bit in one of the INTCON or PIE registers. The exit sequence is initiated when the corresponding interrupt flag bit is set. On all exits from Idle or Sleep modes by interrupt, code execution branches to the interrupt vector if the GIE/GIEH bit (INTCON<7>) is set. Otherwise, code execution continues or resumes without branching (see Section 9.0 "Interrupts"). 4.5.2 EXIT BY WDT TIME-OUT A WDT time-out will cause different actions depending on which power-managed mode the device is in when the time-out occurs. If the device is not executing code (all Idle modes and Sleep mode), the time-out will result in an exit from the power-managed mode (see Section 4.2 "Run Modes" and Section 4.3 "Sleep Mode"). If the device is executing code (all Run modes), the time-out will result in a WDT Reset (see Section 23.2 "Watchdog Timer (WDT)"). The Watchdog Timer and postscaler are cleared by one of the following events: * executing a SLEEP or CLRWDT instruction * the loss of a currently selected clock source (if the Fail-Safe Clock Monitor is enabled) 4.5.3 EXIT BY RESET Exiting an Idle or Sleep mode by Reset automatically forces the device to run from the INTRC. 4.5.4 EXIT WITHOUT AN OSCILLATOR START-UP DELAY Certain exits from power-managed modes do not invoke the OST at all. There are two cases: * PRI_IDLE mode, where the primary clock source is not stopped; and * the primary clock source is either the EC or ECPLL mode. In these instances, the primary clock source either does not require an oscillator start-up delay, since it is already running (PRI_IDLE), or normally does not require an oscillator start-up delay (EC). However, a fixed delay of interval TCSD, following the wake event, is still required when leaving Sleep and Idle modes to allow the CPU to prepare for execution. Instruction execution resumes on the first clock cycle following this delay. A fixed delay of interval TCSD, following the wake event, is required when leaving Sleep and Idle modes. This delay is required for the CPU to prepare for execution. Instruction execution resumes on the first clock cycle following this delay. 2010 Microchip Technology Inc. DS39770C-page 49 PIC18F85J90 FAMILY NOTES: DS39770C-page 50 2010 Microchip Technology Inc. PIC18F85J90 FAMILY 5.0 RESET 5.1 The PIC18F85J90 family of devices differentiate between various kinds of Reset: a) b) c) d) e) f) g) h) Power-on Reset (POR) MCLR Reset during normal operation MCLR Reset during power-managed modes Watchdog Timer (WDT) Reset (during execution) Brown-out Reset (BOR) RESET Instruction Stack Full Reset Stack Underflow Reset RCON Register Device Reset events are tracked through the RCON register (Register 5-1). The lower five bits of the register indicate that a specific Reset event has occurred. In most cases, these bits can only be set by the event and must be cleared by the application after the event. The state of these flag bits, taken together, can be read to indicate the type of Reset that just occurred. This is described in more detail in Section 5.7 "Reset State of Registers". The RCON register also has a control bit for setting interrupt priority (IPEN). Interrupt priority is discussed in Section 9.0 "Interrupts". This section discusses Resets generated by MCLR, POR and BOR, and covers the operation of the various start-up timers. Stack Reset events are covered in Section 6.1.4.4 "Stack Full and Underflow Resets". WDT Resets are covered in Section 23.2 "Watchdog Timer (WDT)". A simplified block diagram of the on-chip Reset circuit is shown in Figure 5-1. FIGURE 5-1: SIMPLIFIED BLOCK DIAGRAM OF ON-CHIP RESET CIRCUIT RESET Instruction Stack Pointer Stack Full/Underflow Reset External Reset MCLR ( )_IDLE Sleep WDT Time-out VDD Rise Detect VDD POR Pulse Brown-out Reset(1) S PWRT 32 s PWRT INTRC Note 1: 65.5 ms 11-Bit Ripple Counter Chip_Reset R Q The ENVREG pin must be tied high to enable Brown-out Reset. The Brown-out Reset is provided by the on-chip voltage regulator when there is insufficient source voltage to maintain regulation. 2010 Microchip Technology Inc. DS39770C-page 51 PIC18F85J90 FAMILY REGISTER 5-1: RCON: RESET CONTROL REGISTER R/W-0 U-0 R/W-1 R/W-1 R-1 R-1 R/W-0 R/W-0 IPEN -- CM RI TO PD POR BOR bit 7 bit 0 Legend: R = Readable bit W = Writable bit U = Unimplemented bit, read as `0' -n = Value at POR `1' = Bit is set `0' = Bit is cleared x = Bit is unknown bit 7 IPEN: Interrupt Priority Enable bit 1 = Enable priority levels on interrupts 0 = Disable priority levels on interrupts (PIC16XXXX Compatibility mode) bit 6 Unimplemented: Read as `0' bit 5 CM: Configuration Mismatch Flag bit 1 = A Configuration Mismatch Reset has not occurred 0 = A Configuration Mismatch Reset occurred. Must be set in software once the Reset occurs. bit 4 RI: RESET Instruction Flag bit 1 = The RESET instruction was not executed (set by firmware only) 0 = The RESET instruction was executed causing a device Reset (must be set in software after a Brown-out Reset occurs) bit 3 TO: Watchdog Time-out Flag bit 1 = Set by power-up, CLRWDT instruction or SLEEP instruction 0 = A WDT time-out occurred bit 2 PD: Power-Down Detection Flag bit 1 = Set by power-up or by the CLRWDT instruction 0 = Set by execution of the SLEEP instruction bit 1 POR: Power-on Reset Status bit 1 = A Power-on Reset has not occurred (set by firmware only) 0 = A Power-on Reset occurred (must be set in software after a Power-on Reset occurs) bit 0 BOR: Brown-out Reset Status bit 1 = A Brown-out Reset has not occurred (set by firmware only) 0 = A Brown-out Reset occurred (must be set in software after a Brown-out Reset occurs) Note 1: It is recommended that the POR bit be set after a Power-on Reset has been detected, so that subsequent Power-on Resets may be detected. 2: If the on-chip voltage regulator is disabled, BOR remains `0' at all times. See Section 5.4.1 "Detecting BOR" for more information. 3: Brown-out Reset is said to have occurred when BOR is `0' and POR is `1' (assuming that POR was set to `1' by software immediately after a Power-on Reset). DS39770C-page 52 2010 Microchip Technology Inc. PIC18F85J90 FAMILY 5.2 Master Clear (MCLR) FIGURE 5-2: The MCLR pin provides a method for triggering a hard external Reset of the device. A Reset is generated by holding the pin low. PIC18 extended microcontroller devices have a noise filter in the MCLR Reset path which detects and ignores small pulses. 5.3 D C Power-on Reset events are captured by the POR bit (RCON<1>). The state of the bit is set to `0' whenever a Power-on Reset occurs; it does not change for any other Reset event. POR is not reset to `1' by any hardware event. To capture multiple events, the user manually resets the bit to `1' in software following any Power-on Reset. 5.4 Brown-out Reset (BOR) The PIC18F85J90 family of devices incorporates a simple BOR function when the internal regulator is enabled (ENVREG pin is tied to VDD). The voltage regulator will trigger a Brown-out Reset when output of the regulator to the device core approaches the voltage at which the device is unable to run at full speed. The BOR circuit also keeps the device in Reset as VDD rises, until the regulator's output level is sufficient for full-speed operation. Once a BOR has occurred, the Power-up Timer will keep the chip in Reset for TPWRT (parameter 33). If VDD drops below the threshold for full-speed operation while the Power-up Timer is running, the chip will go back into a Brown-out Reset and the Power-up Timer will be initialized. Once VDD rises to the point where regulator output is sufficient, the Power-up Timer will execute the additional time delay. 2010 Microchip Technology Inc. MCLR PIC18F85J90 Note 1: External Power-on Reset circuit is required only if the VDD power-up slope is too slow. The diode D helps discharge the capacitor quickly when VDD powers down. 2: R < 40 k is recommended to make sure that the voltage drop across R does not violate the device's electrical specification. 3: R1 1 k will limit any current flowing into MCLR from external capacitor C, in the event of MCLR/VPP pin breakdown, due to Electrostatic Discharge (ESD) or Electrical Overstress (EOS). To take advantage of the POR circuitry, tie the MCLR pin through a resistor (1 k to 10 k) to VDD. This will eliminate external RC components usually needed to create a Power-on Reset delay. A minimum rise rate for VDD is specified (parameter D004). For a slow rise time, see Figure 5-2. When the device starts normal operation (i.e., exits the Reset condition), device operating parameters (voltage, frequency, temperature, etc.) must be met to ensure operation. If these conditions are not met, the device must be held in Reset until the operating conditions are met. R R1 Power-on Reset (POR) A Power-on Reset condition is generated on-chip whenever VDD rises above a certain threshold. This allows the device to start in the initialized state when VDD is adequate for operation. VDD VDD The MCLR pin is not driven low by any internal Resets, including the WDT. EXTERNAL POWER-ON RESET CIRCUIT (FOR SLOW VDD POWER-UP) 5.4.1 DETECTING BOR The BOR bit always resets to `0' on any Brown-out Reset or Power-on Reset event. This makes it difficult to determine if a Brown-out Reset event has occurred just by reading the state of BOR alone. A more reliable method is to simultaneously check the state of both POR and BOR. This assumes that the POR bit is reset to `1' in software immediately after any Power-on Reset event. If BOR is `0' while POR is `1', it can be reliably assumed that a Brown-out Reset event has occurred. If the voltage regulator is disabled, Brown-out Reset functionality is disabled. In this case, the BOR bit cannot be used to determine a Brown-out Reset event. The BOR bit is still cleared by a Power-on Reset event. 5.5 Configuration Mismatch (CM) The Configuration Mismatch (CM) Reset register is designed to detect and attempt to recover from random, memory corrupting events. This includes Electrostatic Discharge (ESD) events which can cause widespread, single bit changes throughout the device and result in catastrophic failure. In PIC18FXXXX Flash devices, the device Configuration registers (located in the configuration memory space) are continuously monitored during operation by comparing their values to complimentary shadow registers. If a mismatch is detected between the two sets of registers, a CM Reset automatically occurs. These events are captured by the CM bit (RCON<5>). Whenever a CM event occurs, this bit is set to `0'. For any other Reset event, this bit does not change. DS39770C-page 53 PIC18F85J90 FAMILY A CM Reset behaves similarly to a Master Clear Reset, RESET instruction, WDT time-out or Stack Event Resets. As with all hard and power Reset events, the device Configuration Words are reloaded from the Flash Configuration Words in program memory as the device restarts. 5.6 Power-up Timer (PWRT) PIC18F85J90 family devices incorporate an on-chip Power-up Timer (PWRT) to help regulate the Power-on Reset process. The PWRT is always enabled. The main function is to ensure that the device voltage is stable before code is executed. The Power-up Timer (PWRT) of the PIC18F85J90 family devices is an 11-bit counter which uses the INTRC source as the clock input. This yields an approximate time interval of 2048 x 32 s = 65.6 ms. While the PWRT is counting, the device is held in Reset. FIGURE 5-3: The power-up time delay depends on the INTRC clock and will vary from chip-to-chip due to temperature and process variation. See DC parameter 33 for details. 5.6.1 TIME-OUT SEQUENCE If enabled, the PWRT time-out is invoked after the POR pulse has cleared. The total time-out will vary based on the status of the PWRT. Figure 5-3, Figure 5-4, Figure 5-5 and Figure 5-6 all depict time-out sequences on power-up with the Power-up Timer enabled. Since the time-outs occur from the POR pulse, if MCLR is kept low long enough, the PWRT will expire. Bringing MCLR high will begin execution immediately (Figure 5-5). This is useful for testing purposes, or to synchronize more than one PIC18FXXXX device operating in parallel. TIME-OUT SEQUENCE ON POWER-UP (MCLR TIED TO VDD, VDD RISE < TPWRT) VDD MCLR INTERNAL POR TPWRT PWRT TIME-OUT INTERNAL RESET FIGURE 5-4: TIME-OUT SEQUENCE ON POWER-UP (MCLR NOT TIED TO VDD): CASE 1 VDD MCLR INTERNAL POR TPWRT PWRT TIME-OUT INTERNAL RESET DS39770C-page 54 2010 Microchip Technology Inc. PIC18F85J90 FAMILY FIGURE 5-5: TIME-OUT SEQUENCE ON POWER-UP (MCLR NOT TIED TO VDD): CASE 2 VDD MCLR INTERNAL POR TPWRT PWRT TIME-OUT INTERNAL RESET FIGURE 5-6: SLOW RISE TIME (MCLR TIED TO VDD, VDD RISE > TPWRT) 3.3V VDD 0V 1V MCLR INTERNAL POR TPWRT PWRT TIME-OUT INTERNAL RESET 2010 Microchip Technology Inc. DS39770C-page 55 PIC18F85J90 FAMILY 5.7 Reset State of Registers Table 5-2 describes the Reset states for all of the Special Function Registers. These are categorized by Power-on and Brown-out Resets, Master Clear and WDT Resets and WDT wake-ups. Most registers are unaffected by a Reset. Their status is unknown on POR and unchanged by all other Resets. The other registers are forced to a "Reset state" depending on the type of Reset that occurred. Most registers are not affected by a WDT wake-up, since this is viewed as the resumption of normal operation. Status bits from the RCON register, CM, RI, TO, PD, POR and BOR, are set or cleared differently in different Reset situations, as indicated in Table 5-1. These bits are used in software to determine the nature of the Reset. TABLE 5-1: STATUS BITS, THEIR SIGNIFICANCE AND THE INITIALIZATION CONDITION FOR RCON REGISTER RCON Register STKPTR Register Program Counter(1) CM RI TO PD POR BOR Power-on Reset 0000h 1 1 1 1 0 0 0 0 RESET Instruction 0000h u 0 u u u u u u Brown-out Reset 0000h 1 1 1 1 u 0 u u MCLR during power-managed Run modes 0000h u u 1 u u u u u MCLR during powermanaged Idle modes and Sleep mode 0000h u u 1 0 u u u u WDT time-out during full power or power-managed Run modes 0000h u u 0 u u u u u MCLR during full-power execution 0000h u u u u u u u u Stack Full Reset (STVREN = 1) 0000h u u u u u u 1 u Stack Underflow Reset (STVREN = 1) 0000h u u u u u u u 1 Stack Underflow Error (not an actual Reset, STVREN = 0) 0000h u u u u u u u 1 WDT time-out during power-managed Idle or Sleep modes PC + 2 u u 0 0 u u u u Interrupt exit from power-managed modes PC + 2 u u u 0 u u u u Condition STKFUL STKUNF Legend: u = unchanged Note 1: When the wake-up is due to an interrupt and the GIEH or GIEL bit is set, the PC is loaded with the interrupt vector (0008h or 0018h). DS39770C-page 56 2010 Microchip Technology Inc. PIC18F85J90 FAMILY TABLE 5-2: INITIALIZATION CONDITIONS FOR ALL REGISTERS Applicable Devices Power-on Reset, Brown-out Reset MCLR Resets WDT Reset RESET Instruction Stack Resets CM Resets TOSU PIC18F6XJ90 PIC18F8XJ90 ---0 0000 ---0 0000 ---0 uuuu(1) TOSH PIC18F6XJ90 PIC18F8XJ90 0000 0000 0000 0000 uuuu uuuu(1) TOSL PIC18F6XJ90 PIC18F8XJ90 0000 0000 0000 0000 uuuu uuuu(1) STKPTR PIC18F6XJ90 PIC18F8XJ90 uu-0 0000 00-0 0000 uu-u uuuu(1) PCLATU PIC18F6XJ90 PIC18F8XJ90 ---0 0000 ---0 0000 ---u uuuu PCLATH PIC18F6XJ90 PIC18F8XJ90 0000 0000 0000 0000 uuuu uuuu PCL PIC18F6XJ90 PIC18F8XJ90 0000 0000 0000 0000 PC + 2(2) TBLPTRU PIC18F6XJ90 PIC18F8XJ90 --00 0000 --00 0000 --uu uuuu TBLPTRH PIC18F6XJ90 PIC18F8XJ90 0000 0000 0000 0000 uuuu uuuu TBLPTRL PIC18F6XJ90 PIC18F8XJ90 0000 0000 0000 0000 uuuu uuuu TABLAT PIC18F6XJ90 PIC18F8XJ90 0000 0000 0000 0000 uuuu uuuu PRODH PIC18F6XJ90 PIC18F8XJ90 xxxx xxxx uuuu uuuu uuuu uuuu PRODL PIC18F6XJ90 PIC18F8XJ90 xxxx xxxx uuuu uuuu uuuu uuuu INTCON PIC18F6XJ90 PIC18F8XJ90 0000 000x 0000 000u uuuu uuuu(3) INTCON2 PIC18F6XJ90 PIC18F8XJ90 1111 1111 1111 1111 uuuu uuuu(3) INTCON3 PIC18F6XJ90 PIC18F8XJ90 1100 0000 1100 0000 uuuu uuuu(3) INDF0 PIC18F6XJ90 PIC18F8XJ90 N/A N/A N/A Register Wake-up via WDT or Interrupt POSTINC0 PIC18F6XJ90 PIC18F8XJ90 N/A N/A N/A POSTDEC0 PIC18F6XJ90 PIC18F8XJ90 N/A N/A N/A PREINC0 PIC18F6XJ90 PIC18F8XJ90 N/A N/A N/A PLUSW0 PIC18F6XJ90 PIC18F8XJ90 N/A N/A N/A FSR0H PIC18F6XJ90 PIC18F8XJ90 ---- xxxx ---- uuuu ---- uuuu FSR0L PIC18F6XJ90 PIC18F8XJ90 xxxx xxxx uuuu uuuu uuuu uuuu WREG PIC18F6XJ90 PIC18F8XJ90 xxxx xxxx uuuu uuuu uuuu uuuu INDF1 PIC18F6XJ90 PIC18F8XJ90 N/A N/A N/A POSTINC1 PIC18F6XJ90 PIC18F8XJ90 N/A N/A N/A POSTDEC1 PIC18F6XJ90 PIC18F8XJ90 N/A N/A N/A PREINC1 PIC18F6XJ90 PIC18F8XJ90 N/A N/A N/A PLUSW1 PIC18F6XJ90 PIC18F8XJ90 N/A N/A N/A Legend: u = unchanged, x = unknown, - = unimplemented bit, read as `0', q = value depends on condition. Shaded cells indicate conditions do not apply for the designated device. Note 1: When the wake-up is due to an interrupt and the GIEL or GIEH bit is set, the TOSU, TOSH and TOSL are updated with the current value of the PC. The STKPTR is modified to point to the next location in the hardware stack. 2: When the wake-up is due to an interrupt and the GIEL or GIEH bit is set, the PC is loaded with the interrupt vector (0008h or 0018h). 3: One or more bits in the INTCONx or PIRx registers will be affected (to cause wake-up). 4: See Table 5-1 for Reset value for specific condition. 5: Bits 6 and 7 of PORTA, LATA and TRISA are enabled depending on the oscillator mode selected. When not enabled as PORTA pins, they are disabled and read as `0'. 2010 Microchip Technology Inc. DS39770C-page 57 PIC18F85J90 FAMILY TABLE 5-2: INITIALIZATION CONDITIONS FOR ALL REGISTERS (CONTINUED) Applicable Devices Power-on Reset, Brown-out Reset MCLR Resets WDT Reset RESET Instruction Stack Resets CM Resets FSR1H PIC18F6XJ90 PIC18F8XJ90 ---- xxxx ---- uuuu ---- uuuu FSR1L PIC18F6XJ90 PIC18F8XJ90 xxxx xxxx uuuu uuuu uuuu uuuu BSR PIC18F6XJ90 PIC18F8XJ90 ---- 0000 ---- 0000 ---- uuuu INDF2 PIC18F6XJ90 PIC18F8XJ90 N/A N/A N/A POSTINC2 PIC18F6XJ90 PIC18F8XJ90 N/A N/A N/A Register Wake-up via WDT or Interrupt POSTDEC2 PIC18F6XJ90 PIC18F8XJ90 N/A N/A N/A PREINC2 PIC18F6XJ90 PIC18F8XJ90 N/A N/A N/A PLUSW2 PIC18F6XJ90 PIC18F8XJ90 N/A N/A N/A FSR2H PIC18F6XJ90 PIC18F8XJ90 ---- xxxx ---- uuuu ---- uuuu FSR2L PIC18F6XJ90 PIC18F8XJ90 xxxx xxxx uuuu uuuu uuuu uuuu STATUS PIC18F6XJ90 PIC18F8XJ90 ---x xxxx ---u uuuu ---u uuuu TMR0H PIC18F6XJ90 PIC18F8XJ90 0000 0000 0000 0000 uuuu uuuu TMR0L PIC18F6XJ90 PIC18F8XJ90 xxxx xxxx uuuu uuuu uuuu uuuu T0CON PIC18F6XJ90 PIC18F8XJ90 1111 1111 1111 1111 uuuu uuuu OSCCON PIC18F6XJ90 PIC18F8XJ90 0100 q000 0100 q000 uuuu quuu LCDREG PIC18F6XJ90 PIC18F8XJ90 -011 1100 -011 1000 -uuu uuuu WDTCON PIC18F6XJ90 PIC18F8XJ90 0--- ---0 0--- ---0 u--- ---u RCON PIC18F6XJ90 PIC18F8XJ90 0-11 11q0 0-qq qquu u-uu qquu TMR1H PIC18F6XJ90 PIC18F8XJ90 xxxx xxxx uuuu uuuu uuuu uuuu TMR1L PIC18F6XJ90 PIC18F8XJ90 xxxx xxxx uuuu uuuu uuuu uuuu T1CON PIC18F6XJ90 PIC18F8XJ90 0000 0000 u0uu uuuu uuuu uuuu TMR2 PIC18F6XJ90 PIC18F8XJ90 0000 0000 0000 0000 uuuu uuuu PR2 PIC18F6XJ90 PIC18F8XJ90 1111 1111 1111 1111 1111 1111 T2CON PIC18F6XJ90 PIC18F8XJ90 -000 0000 -000 0000 -uuu uuuu SSPBUF PIC18F6XJ90 PIC18F8XJ90 xxxx xxxx uuuu uuuu uuuu uuuu SSPADD PIC18F6XJ90 PIC18F8XJ90 0000 0000 0000 0000 uuuu uuuu SSPSTAT PIC18F6XJ90 PIC18F8XJ90 0000 0000 0000 0000 uuuu uuuu SSPCON1 PIC18F6XJ90 PIC18F8XJ90 0000 0000 0000 0000 uuuu uuuu SSPCON2 PIC18F6XJ90 PIC18F8XJ90 0000 0000 0000 0000 uuuu uuuu (4) Legend: u = unchanged, x = unknown, - = unimplemented bit, read as `0', q = value depends on condition. Shaded cells indicate conditions do not apply for the designated device. Note 1: When the wake-up is due to an interrupt and the GIEL or GIEH bit is set, the TOSU, TOSH and TOSL are updated with the current value of the PC. The STKPTR is modified to point to the next location in the hardware stack. 2: When the wake-up is due to an interrupt and the GIEL or GIEH bit is set, the PC is loaded with the interrupt vector (0008h or 0018h). 3: One or more bits in the INTCONx or PIRx registers will be affected (to cause wake-up). 4: See Table 5-1 for Reset value for specific condition. 5: Bits 6 and 7 of PORTA, LATA and TRISA are enabled depending on the oscillator mode selected. When not enabled as PORTA pins, they are disabled and read as `0'. DS39770C-page 58 2010 Microchip Technology Inc. PIC18F85J90 FAMILY TABLE 5-2: INITIALIZATION CONDITIONS FOR ALL REGISTERS (CONTINUED) Applicable Devices Power-on Reset, Brown-out Reset MCLR Resets WDT Reset RESET Instruction Stack Resets CM Resets PIC18F6XJ90 PIC18F8XJ90 xxxx xxxx uuuu uuuu uuuu uuuu ADRESL PIC18F6XJ90 PIC18F8XJ90 xxxx xxxx uuuu uuuu uuuu uuuu ADCON0 PIC18F6XJ90 PIC18F8XJ90 0-00 0000 0-00 0000 u-uu uuuu ADCON1 PIC18F6XJ90 PIC18F8XJ90 --00 0000 --00 0000 --uu uuuu ADCON2 PIC18F6XJ90 PIC18F8XJ90 0-00 0000 0-00 0000 u-uu uuuu LCDDATA4 PIC18F6XJ90 PIC18F8XJ90 ---- ---x ---- ---u ---- ---u LCDDATA4 PIC18F6XJ90 PIC18F8XJ90 xxxx xxxx uuuu uuuu uuuu uuuu LCDDATA3 PIC18F6XJ90 PIC18F8XJ90 xxxx xxxx uuuu uuuu uuuu uuuu LCDDATA2 PIC18F6XJ90 PIC18F8XJ90 xxxx xxxx uuuu uuuu uuuu uuuu LCDDATA1 PIC18F6XJ90 PIC18F8XJ90 xxxx xxxx uuuu uuuu uuuu uuuu LCDDATA0 PIC18F6XJ90 PIC18F8XJ90 xxxx xxxx uuuu uuuu uuuu uuuu LCDSE5 PIC18F6XJ90 PIC18F8XJ90 0000 0000 uuuu uuuu uuuu uuuu LCDSE4 PIC18F6XJ90 PIC18F8XJ90 ---- ---0 ---- ---u ---- ---u Register ADRESH Wake-up via WDT or Interrupt LCDSE4 PIC18F6XJ90 PIC18F8XJ90 0000 0000 uuuu uuuu uuuu uuuu LCDSE3 PIC18F6XJ90 PIC18F8XJ90 0000 0000 uuuu uuuu uuuu uuuu LCDSE2 PIC18F6XJ90 PIC18F8XJ90 0000 0000 uuuu uuuu uuuu uuuu LCDSE1 PIC18F6XJ90 PIC18F8XJ90 0000 0000 uuuu uuuu uuuu uuuu CVRCON PIC18F6XJ90 PIC18F8XJ90 0000 0000 0000 0000 uuuu uuuu CMCON PIC18F6XJ90 PIC18F8XJ90 0000 0111 0000 0111 uuuu uuuu TMR3H PIC18F6XJ90 PIC18F8XJ90 xxxx xxxx uuuu uuuu uuuu uuuu TMR3L PIC18F6XJ90 PIC18F8XJ90 xxxx xxxx uuuu uuuu uuuu uuuu T3CON PIC18F6XJ90 PIC18F8XJ90 0000 0000 uuuu uuuu uuuu uuuu SPBRG1 PIC18F6XJ90 PIC18F8XJ90 0000 0000 0000 0000 uuuu uuuu RCREG1 PIC18F6XJ90 PIC18F8XJ90 0000 0000 0000 0000 uuuu uuuu TXREG1 PIC18F6XJ90 PIC18F8XJ90 0000 0000 0000 0000 uuuu uuuu TXSTA1 PIC18F6XJ90 PIC18F8XJ90 0000 0010 0000 0010 uuuu uuuu RCSTA1 PIC18F6XJ90 PIC18F8XJ90 0000 000x 0000 000x uuuu uuuu LCDPS PIC18F6XJ90 PIC18F8XJ90 0000 0000 0000 0000 uuuu uuuu LCDSE0 PIC18F6XJ90 PIC18F8XJ90 0000 0000 uuuu uuuu uuuu uuuu LCDCON PIC18F6XJ90 PIC18F8XJ90 000- 0000 000- 0000 uuu- uuuu EECON2 PIC18F6XJ90 PIC18F8XJ90 ---- ---- ---- ---- ---- ---- EECON1 PIC18F6XJ90 PIC18F8XJ90 ---0 x00- ---0 u00- ---0 u00- Legend: u = unchanged, x = unknown, - = unimplemented bit, read as `0', q = value depends on condition. Shaded cells indicate conditions do not apply for the designated device. Note 1: When the wake-up is due to an interrupt and the GIEL or GIEH bit is set, the TOSU, TOSH and TOSL are updated with the current value of the PC. The STKPTR is modified to point to the next location in the hardware stack. 2: When the wake-up is due to an interrupt and the GIEL or GIEH bit is set, the PC is loaded with the interrupt vector (0008h or 0018h). 3: One or more bits in the INTCONx or PIRx registers will be affected (to cause wake-up). 4: See Table 5-1 for Reset value for specific condition. 5: Bits 6 and 7 of PORTA, LATA and TRISA are enabled depending on the oscillator mode selected. When not enabled as PORTA pins, they are disabled and read as `0'. 2010 Microchip Technology Inc. DS39770C-page 59 PIC18F85J90 FAMILY TABLE 5-2: INITIALIZATION CONDITIONS FOR ALL REGISTERS (CONTINUED) Register Applicable Devices Power-on Reset, Brown-out Reset MCLR Resets WDT Reset RESET Instruction Stack Resets CM Resets Wake-up via WDT or Interrupt IPR3 PIC18F6XJ90 PIC18F8XJ90 -111 -11- -111 -11- -uuu -uu- PIR3 PIC18F6XJ90 PIC18F8XJ90 -000 -00- -000 -00- -uuu -00-(3) PIE3 PIC18F6XJ90 PIC18F8XJ90 -000 -00- -000 -00- -uuu -00- IPR2 PIC18F6XJ90 PIC18F8XJ90 11-- 111- 11-- 111- uu-- uuu- PIR2 PIC18F6XJ90 PIC18F8XJ90 00-- 000- 00-- 000- uu-- uuu-(3) PIE2 PIC18F6XJ90 PIC18F8XJ90 00-- 000- 00-- 000- uu-- uuu- IPR1 PIC18F6XJ90 PIC18F8XJ90 -111 1-11 -111 1-11 -uuu u-uu PIR1 PIC18F6XJ90 PIC18F8XJ90 -000 0-00 -000 0-00 -uuu u-uu(3) PIE1 PIC18F6XJ90 PIC18F8XJ90 -000 0-00 -000 0-00 -uuu u-uu OSCTUNE PIC18F6XJ90 PIC18F8XJ90 0000 0000 0000 0000 uuuu uuuu TRISJ PIC18F6XJ90 PIC18F8XJ90 1111 1111 1111 1111 uuuu uuuu TRISH PIC18F6XJ90 PIC18F8XJ90 1111 1111 1111 1111 uuuu uuuu TRISG PIC18F6XJ90 PIC18F8XJ90 0001 1111 0001 1111 uuuu uuuu TRISF PIC18F6XJ90 PIC18F8XJ90 1111 111- 1111 111- uuuu uuu- TRISE PIC18F6XJ90 PIC18F8XJ90 1111 1-11 1111 1-11 uuuu u-uu TRISD PIC18F6XJ90 PIC18F8XJ90 1111 1111 1111 1111 uuuu uuuu TRISC PIC18F6XJ90 PIC18F8XJ90 1111 1111 1111 1111 uuuu uuuu TRISB PIC18F6XJ90 PIC18F8XJ90 1111 1111 1111 1111 uuuu uuuu TRISA(5) PIC18F6XJ90 PIC18F8XJ90 1111 1111(5) 1111 1111(5) uuuu uuuu(5) LATJ PIC18F6XJ90 PIC18F8XJ90 xxxx xxxx uuuu uuuu uuuu uuuu LATH PIC18F6XJ90 PIC18F8XJ90 xxxx xxxx uuuu uuuu uuuu uuuu LATG PIC18F6XJ90 PIC18F8XJ90 00-x xxxx 00-u uuuu uu-u uuuu LATF PIC18F6XJ90 PIC18F8XJ90 xxxx xxx- uuuu uuu- uuuu uuu- LATE PIC18F6XJ90 PIC18F8XJ90 xxxx xxxx uuuu uuuu uuuu uuuu LATD PIC18F6XJ90 PIC18F8XJ90 xxxx xxxx uuuu uuuu uuuu uuuu LATC PIC18F6XJ90 PIC18F8XJ90 xxxx xxxx uuuu uuuu uuuu uuuu LATB PIC18F6XJ90 PIC18F8XJ90 xxxx xxxx uuuu uuuu (5) uuuu uuuu (5) LATA PIC18F6XJ90 PIC18F8XJ90 xxxx xxxx PORTJ PIC18F6XJ90 PIC18F8XJ90 xxxx xxxx uuuu uuuu uuuu uuuu PORTH PIC18F6XJ90 PIC18F8XJ90 xxxx xxxx uuuu uuuu uuuu uuuu PORTG PIC18F6XJ90 PIC18F8XJ90 000x xxxx 000u uuuu 000u uuuu PORTF PIC18F6XJ90 PIC18F8XJ90 xxxx xxx- uuuu uuu- uuuu uuu- uuuu uuuu (5) uuuu uuuu(5) Legend: u = unchanged, x = unknown, - = unimplemented bit, read as `0', q = value depends on condition. Shaded cells indicate conditions do not apply for the designated device. Note 1: When the wake-up is due to an interrupt and the GIEL or GIEH bit is set, the TOSU, TOSH and TOSL are updated with the current value of the PC. The STKPTR is modified to point to the next location in the hardware stack. 2: When the wake-up is due to an interrupt and the GIEL or GIEH bit is set, the PC is loaded with the interrupt vector (0008h or 0018h). 3: One or more bits in the INTCONx or PIRx registers will be affected (to cause wake-up). 4: See Table 5-1 for Reset value for specific condition. 5: Bits 6 and 7 of PORTA, LATA and TRISA are enabled depending on the oscillator mode selected. When not enabled as PORTA pins, they are disabled and read as `0'. DS39770C-page 60 2010 Microchip Technology Inc. PIC18F85J90 FAMILY TABLE 5-2: Register INITIALIZATION CONDITIONS FOR ALL REGISTERS (CONTINUED) Applicable Devices Power-on Reset, Brown-out Reset MCLR Resets WDT Reset RESET Instruction Stack Resets CM Resets Wake-up via WDT or Interrupt PORTE PIC18F6XJ90 PIC18F8XJ90 xxxx x-xx uuuu u-uu uuuu u-uu PORTD PIC18F6XJ90 PIC18F8XJ90 xxxx xxxx uuuu uuuu uuuu uuuu PORTC PIC18F6XJ90 PIC18F8XJ90 xxxx xxxx uuuu uuuu uuuu uuuu PORTB PIC18F6XJ90 PIC18F8XJ90 xxxx xxxx uuuu uuuu uuuu uuuu PORTA(5) PIC18F6XJ90 PIC18F8XJ90 xx0x 0000(5) uu0u 0000(5) uuuu uuuu(5) SPBRGH1 PIC18F6XJ90 PIC18F8XJ90 0000 0000 0000 0000 uuuu uuuu BAUDCON1 PIC18F6XJ90 PIC18F8XJ90 0100 0-00 0100 0-00 uuuu u-uu LCDDATA23 PIC18F6XJ90 PIC18F8XJ90 xxxx xxxx uuuu uuuu uuuu uuuu LCDDATA22 PIC18F6XJ90 PIC18F8XJ90 ---- ---x ---- ---u ---- ---u LCDDATA22 PIC18F6XJ90 PIC18F8XJ90 xxxx xxxx uuuu uuuu uuuu uuuu LCDDATA21 PIC18F6XJ90 PIC18F8XJ90 xxxx xxxx uuuu uuuu uuuu uuuu LCDDATA20 PIC18F6XJ90 PIC18F8XJ90 xxxx xxxx uuuu uuuu uuuu uuuu LCDDATA19 PIC18F6XJ90 PIC18F8XJ90 xxxx xxxx uuuu uuuu uuuu uuuu LCDDATA18 PIC18F6XJ90 PIC18F8XJ90 xxxx xxxx uuuu uuuu uuuu uuuu LCDDATA17 PIC18F6XJ90 PIC18F8XJ90 xxxx xxxx uuuu uuuu uuuu uuuu LCDDATA16 PIC18F6XJ90 PIC18F8XJ90 ---- ---x ---- ---u ---- ---u LCDDATA16 PIC18F6XJ90 PIC18F8XJ90 xxxx xxxx uuuu uuuu uuuu uuuu LCDDATA15 PIC18F6XJ90 PIC18F8XJ90 xxxx xxxx uuuu uuuu uuuu uuuu LCDDATA14 PIC18F6XJ90 PIC18F8XJ90 xxxx xxxx uuuu uuuu uuuu uuuu LCDDATA13 PIC18F6XJ90 PIC18F8XJ90 xxxx xxxx uuuu uuuu uuuu uuuu LCDDATA12 PIC18F6XJ90 PIC18F8XJ90 xxxx xxxx uuuu uuuu uuuu uuuu LCDDATA11 PIC18F6XJ90 PIC18F8XJ90 xxxx xxxx uuuu uuuu uuuu uuuu LCDDATA10 PIC18F6XJ90 PIC18F8XJ90 ---- ---x ---- ---u ---- ---u LCDDATA10 PIC18F6XJ90 PIC18F8XJ90 xxxx xxxx uuuu uuuu uuuu uuuu LCDDATA9 PIC18F6XJ90 PIC18F8XJ90 xxxx xxxx uuuu uuuu uuuu uuuu LCDDATA8 PIC18F6XJ90 PIC18F8XJ90 xxxx xxxx uuuu uuuu uuuu uuuu LCDDATA7 PIC18F6XJ90 PIC18F8XJ90 xxxx xxxx uuuu uuuu uuuu uuuu LCDDATA6 PIC18F6XJ90 PIC18F8XJ90 xxxx xxxx uuuu uuuu uuuu uuuu LCDDATA5 PIC18F6XJ90 PIC18F8XJ90 xxxx xxxx uuuu uuuu uuuu uuuu CCPR1H PIC18F6XJ90 PIC18F8XJ90 xxxx xxxx uuuu uuuu uuuu uuuu CCPR1L PIC18F6XJ90 PIC18F8XJ90 xxxx xxxx uuuu uuuu uuuu uuuu CCP1CON PIC18F6XJ90 PIC18F8XJ90 --00 0000 --00 0000 --uu uuuu CCPR2H PIC18F6XJ90 PIC18F8XJ90 xxxx xxxx uuuu uuuu uuuu uuuu Legend: u = unchanged, x = unknown, - = unimplemented bit, read as `0', q = value depends on condition. Shaded cells indicate conditions do not apply for the designated device. Note 1: When the wake-up is due to an interrupt and the GIEL or GIEH bit is set, the TOSU, TOSH and TOSL are updated with the current value of the PC. The STKPTR is modified to point to the next location in the hardware stack. 2: When the wake-up is due to an interrupt and the GIEL or GIEH bit is set, the PC is loaded with the interrupt vector (0008h or 0018h). 3: One or more bits in the INTCONx or PIRx registers will be affected (to cause wake-up). 4: See Table 5-1 for Reset value for specific condition. 5: Bits 6 and 7 of PORTA, LATA and TRISA are enabled depending on the oscillator mode selected. When not enabled as PORTA pins, they are disabled and read as `0'. 2010 Microchip Technology Inc. DS39770C-page 61 PIC18F85J90 FAMILY TABLE 5-2: INITIALIZATION CONDITIONS FOR ALL REGISTERS (CONTINUED) Applicable Devices Power-on Reset, Brown-out Reset MCLR Resets WDT Reset RESET Instruction Stack Resets CM Resets CCPR2L PIC18F6XJ90 PIC18F8XJ90 xxxx xxxx uuuu uuuu uuuu uuuu CCP2CON PIC18F6XJ90 PIC18F8XJ90 --00 0000 --00 0000 --uu uuuu SPBRG2 PIC18F6XJ90 PIC18F8XJ90 0000 0000 0000 0000 uuuu uuuu RCREG2 PIC18F6XJ90 PIC18F8XJ90 0000 0000 0000 0000 uuuu uuuu TXREG2 PIC18F6XJ90 PIC18F8XJ90 0000 0000 0000 0000 uuuu uuuu TXSTA2 PIC18F6XJ90 PIC18F8XJ90 0000 -010 0000 -010 uuuu -uuu RCSTA2 PIC18F6XJ90 PIC18F8XJ90 0000 000x 0000 000x uuuu uuuu Register Wake-up via WDT or Interrupt Legend: u = unchanged, x = unknown, - = unimplemented bit, read as `0', q = value depends on condition. Shaded cells indicate conditions do not apply for the designated device. Note 1: When the wake-up is due to an interrupt and the GIEL or GIEH bit is set, the TOSU, TOSH and TOSL are updated with the current value of the PC. The STKPTR is modified to point to the next location in the hardware stack. 2: When the wake-up is due to an interrupt and the GIEL or GIEH bit is set, the PC is loaded with the interrupt vector (0008h or 0018h). 3: One or more bits in the INTCONx or PIRx registers will be affected (to cause wake-up). 4: See Table 5-1 for Reset value for specific condition. 5: Bits 6 and 7 of PORTA, LATA and TRISA are enabled depending on the oscillator mode selected. When not enabled as PORTA pins, they are disabled and read as `0'. DS39770C-page 62 2010 Microchip Technology Inc. PIC18F85J90 FAMILY 6.0 MEMORY ORGANIZATION There are two types of memory in PIC18 Flash microcontroller devices: * Program Memory * Data RAM As Harvard architecture devices, the data and program memories use separate busses; this allows for concurrent access of the two memory spaces. Additional detailed information on the operation of the Flash program memory is provided in Section 7.0 "Flash Program Memory". FIGURE 6-1: 6.1 Program Memory Organization PIC18 microcontrollers implement a 21-bit program counter which is capable of addressing a 2-Mbyte program memory space. Accessing a location between the upper boundary of the physically implemented memory and the 2-Mbyte address will return all `0's (a NOP instruction). The entire PIC18F85J90 family offers a range of on-chip Flash program memory sizes, from 8 Kbytes (up to 4,096 single-word instructions) to 32 Kbytes (32,768 single-word instructions). The program memory maps for individual family members are shown in Figure 6-1. MEMORY MAPS FOR PIC18F85J90 FAMILY DEVICES PC<20:0> CALL, CALLW, RCALL, RETURN, RETFIE, RETLW, ADDULNK, SUBULNK 21 Stack Level 1 Stack Level 31 PIC18FX4J90 On-Chip Memory PIC18FX5J90 On-Chip Memory Config. Words 000000h 001FFFh Config. Words 003FFFh Config. Words Unimplemented Unimplemented Unimplemented Read as `0' Read as `0' Read as `0' 007FFFh User Memory Space PIC18FX3J90 On-Chip Memory 1FFFFFh Note: Sizes of memory areas are not to scale. Sizes of program memory areas are enhanced to show detail. 2010 Microchip Technology Inc. DS39770C-page 63 PIC18F85J90 FAMILY 6.1.1 HARD MEMORY VECTORS 6.1.2 FLASH CONFIGURATION WORDS All PIC18 devices have a total of three hard-coded return vectors in their program memory space. The Reset vector address is the default value to which the program counter returns on all device Resets; it is located at 0000h. Because PIC18F85J90 family devices do not have persistent configuration memory, the top four words of on-chip program memory are reserved for configuration information. On Reset, the configuration information is copied into the Configuration registers. PIC18 devices also have two interrupt vector addresses for the handling of high-priority and low-priority interrupts. The high-priority interrupt vector is located at 0008h and the low-priority interrupt vector is at 0018h. Their locations in relation to the program memory map are shown in Figure 6-2. The Configuration Words are stored in their program memory location in numerical order, starting with the lower byte of CONFIG1 at the lowest address and ending with the upper byte of CONFIG4. For these devices, only Configuration Words, CONFIG1 through CONFIG3, are used; CONFIG4 is reserved. The actual addresses of the Flash Configuration Word for devices in the PIC18F85J90 family are shown in Table 6-1. Their location in the memory map is shown with the other memory vectors in Figure 6-2. FIGURE 6-2: HARD VECTOR AND CONFIGURATION WORD LOCATIONS FOR PIC18F85J90 FAMILY FAMILY DEVICES Reset Vector 0000h High-Priority Interrupt Vector 0008h Low-Priority Interrupt Vector 0018h Additional details on the device Configuration Words are provided in Section 23.1 "Configuration Bits". TABLE 6-1: Device PIC18F63J90 On-Chip Program Memory PIC18F83J90 PIC18F64J90 PIC18F84J90 PIC18F65J90 PIC18F85J90 Flash Configuration Words FLASH CONFIGURATION WORD FOR PIC18F85J90 FAMILY DEVICES Program Memory (Kbytes) Configuration Word Addresses 8 1FF8h to 1FFFh 16 3FF8h to 3FFFh 32 7FF8h to 7FFFh (Top of Memory-7) (Top of Memory) Read `0' 1FFFFFh Legend: (Top of Memory) represents upper boundary of on-chip program memory space (see Figure 6-1 for device-specific values). Shaded area represents unimplemented memory. Areas are not shown to scale. DS39770C-page 64 2010 Microchip Technology Inc. PIC18F85J90 FAMILY 6.1.3 PROGRAM COUNTER The Program Counter (PC) specifies the address of the instruction to fetch for execution. The PC is 21 bits wide and is contained in three separate 8-bit registers. The low byte, known as the PCL register, is both readable and writable. The high byte, or PCH register, contains the PC<15:8> bits; it is not directly readable or writable. Updates to the PCH register are performed through the PCLATH register. The upper byte is called PCU. This register contains the PC<20:16> bits; it is also not directly readable or writable. Updates to the PCU register are performed through the PCLATU register. The contents of PCLATH and PCLATU are transferred to the program counter by any operation that writes PCL. Similarly, the upper two bytes of the program counter are transferred to PCLATH and PCLATU by an operation that reads PCL. This is useful for computed offsets to the PC (see Section 6.1.6.1 "Computed GOTO"). The PC addresses bytes in the program memory. To prevent the PC from becoming misaligned with word instructions, the Least Significant bit of PCL is fixed to a value of `0'. The PC increments by 2 to address sequential instructions in the program memory. The CALL, RCALL, GOTO and program branch instructions write to the program counter directly. For these instructions, the contents of PCLATH and PCLATU are not transferred to the program counter. 6.1.4 RETURN ADDRESS STACK The return address stack allows any combination of up to 31 program calls and interrupts to occur. The PC is pushed onto the stack when a CALL or RCALL instruction is executed, or an interrupt is Acknowledged. The PC value is pulled off the stack on a RETURN, RETLW or a RETFIE instruction (and on ADDULNK and SUBULNK instructions if the extended instruction set is enabled). PCLATU and PCLATH are not affected by any of the RETURN or CALL instructions. FIGURE 6-3: The stack operates as a 31-word by 21-bit RAM and a 5-bit Stack Pointer, STKPTR. The stack space is not part of either program or data space. The Stack Pointer is readable and writable and the address on the top of the stack is readable and writable through the Top-of-Stack Special Function Registers. Data can also be pushed to, or popped from, the stack using these registers. A CALL type instruction causes a push onto the stack. The Stack Pointer is first incremented and the location pointed to by the Stack Pointer is written with the contents of the PC (already pointing to the instruction following the CALL). A RETURN type instruction causes a pop from the stack. The contents of the location pointed to by the STKPTR are transferred to the PC and then the Stack Pointer is decremented. The Stack Pointer is initialized to `00000' after all Resets. There is no RAM associated with the location corresponding to a Stack Pointer value of `00000'; this is only a Reset value. Status bits indicate if the stack is full, has overflowed or has underflowed. 6.1.4.1 Top-of-Stack Access Only the top of the return address stack (TOS) is readable and writable. A set of three registers, TOSU:TOSH:TOSL, holds the contents of the stack location pointed to by the STKPTR register (Figure 6-3). This allows users to implement a software stack if necessary. After a CALL, RCALL or interrupt (and ADDULNK and SUBULNK instructions if the extended instruction set is enabled), the software can read the pushed value by reading the TOSU:TOSH:TOSL registers. These values can be placed on a user-defined software stack. At return time, the software can return these values to TOSU:TOSH:TOSL and do a return. The user must disable the global interrupt enable bits while accessing the stack to prevent inadvertent stack corruption. RETURN ADDRESS STACK AND ASSOCIATED REGISTERS Return Address Stack <20:0> Top-of-Stack Registers TOSU 00h TOSH 1Ah TOSL 34h Top-of-Stack 2010 Microchip Technology Inc. 11111 11110 11101 001A34h 000D58h Stack Pointer STKPTR<4:0> 00010 00011 00010 00001 00000 DS39770C-page 65 PIC18F85J90 FAMILY 6.1.4.2 Return Stack Pointer (STKPTR) The STKPTR register (Register 6-1) contains the Stack Pointer value, the STKFUL (Stack Full) status bit and the STKUNF (Stack Underflow) status bits. The value of the Stack Pointer can be 0 through 31. The Stack Pointer increments before values are pushed onto the stack and decrements after values are popped off the stack. On Reset, the Stack Pointer value will be zero. The user may read and write the Stack Pointer value. This feature can be used by a Real-Time Operating System (RTOS) for return stack maintenance. After the PC is pushed onto the stack 31 times (without popping any values off the stack), the STKFUL bit is set. The STKFUL bit is cleared by software or by a POR. The action that takes place when the stack becomes full depends on the state of the STVREN (Stack Overflow Reset Enable) Configuration bit. (Refer to Section 23.1 "Configuration Bits" for a description of the device Configuration bits.) If STVREN is set (default), the 31st push will push the (PC + 2) value onto the stack, set the STKFUL bit and reset the device. The STKFUL bit will remain set and the Stack Pointer will be set to zero. If STVREN is cleared, the STKFUL bit will be set on the 31st push and the Stack Pointer will increment to 31. Any additional pushes will not overwrite the 31st push and the STKPTR will remain at 31. REGISTER 6-1: When the stack has been popped enough times to unload the stack, the next pop will return a value of zero to the PC and set the STKUNF bit, while the Stack Pointer remains at zero. The STKUNF bit will remain set until cleared by software or until a POR occurs. Note: 6.1.4.3 Returning a value of zero to the PC on an underflow has the effect of vectoring the program to the Reset vector, where the stack conditions can be verified and appropriate actions can be taken. This is not the same as a Reset, as the contents of the SFRs are not affected. PUSH and POP Instructions Since the Top-of-Stack is readable and writable, the ability to push values onto the stack and pull values off the stack, without disturbing normal program execution, is a desirable feature. The PIC18 instruction set includes two instructions, PUSH and POP, that permit the TOS to be manipulated under software control. TOSU, TOSH and TOSL can be modified to place data or a return address on the stack. The PUSH instruction places the current PC value onto the stack. This increments the Stack Pointer and loads the current PC value onto the stack. The POP instruction discards the current TOS by decrementing the Stack Pointer. The previous value pushed onto the stack then becomes the TOS value. STKPTR: STACK POINTER REGISTER R/C-0 R/C-0 U-0 R/W-0 R/W-0 R/W-0 R/W-0 R/W-0 STKFUL(1) STKUNF(1) -- SP4 SP3 SP2 SP1 SP0 bit 7 bit 0 Legend: C = Clearable-only bit R = Readable bit W = Writable bit U = Unimplemented bit, read as `0' -n = Value at POR `1' = Bit is set `0' = Bit is cleared bit 7 STKFUL: Stack Full Flag bit(1) 1 = Stack has become full or overflowed 0 = Stack has not become full or overflowed bit 6 STKUNF: Stack Underflow Flag bit(1) 1 = Stack underflow occurred 0 = Stack underflow did not occur bit 5 Unimplemented: Read as `0' bit 4-0 SP<4:0>: Stack Pointer Location bits Note 1: x = Bit is unknown Bit 7 and bit 6 are cleared by user software or by a POR. DS39770C-page 66 2010 Microchip Technology Inc. PIC18F85J90 FAMILY 6.1.4.4 Stack Full and Underflow Resets Device Resets on stack overflow and stack underflow conditions are enabled by setting the STVREN bit in Configuration Register 1L. When STVREN is set, a full or underflow condition will set the appropriate STKFUL or STKUNF bit and then cause a device Reset. When STVREN is cleared, a full or underflow condition will set the appropriate STKFUL or STKUNF bit, but not cause a device Reset. The STKFUL or STKUNF bits are cleared by the user software or a Power-on Reset. 6.1.5 FAST REGISTER STACK A Fast Register Stack is provided for the STATUS, WREG and BSR registers to provide a "fast return" option for interrupts. This stack is only one level deep and is neither readable nor writable. It is loaded with the current value of the corresponding register when the processor vectors for an interrupt. All interrupt sources will push values into the Stack registers. The values in the registers are then loaded back into the working registers if the RETFIE, FAST instruction is used to return from the interrupt. 6.1.6 LOOK-UP TABLES IN PROGRAM MEMORY There may be programming situations that require the creation of data structures, or look-up tables, in program memory. For PIC18 devices, look-up tables can be implemented in two ways: * Computed GOTO * Table Reads 6.1.6.1 Computed GOTO A computed GOTO is accomplished by adding an offset to the program counter. An example is shown in Example 6-2. A look-up table can be formed with an ADDWF PCL instruction and a group of RETLW nn instructions. The W register is loaded with an offset into the table before executing a call to that table. The first instruction of the called routine is the ADDWF PCL instruction. The next instruction executed will be one of the RETLW nn instructions that returns the value `nn' to the calling function. If both low and high-priority interrupts are enabled, the Stack registers cannot be used reliably to return from low-priority interrupts. If a high-priority interrupt occurs while servicing a low-priority interrupt, the Stack register values stored by the low-priority interrupt will be overwritten. In these cases, users must save the key registers in software during a low-priority interrupt. The offset value (in WREG) specifies the number of bytes that the program counter should advance and should be multiples of 2 (LSb = 0). If interrupt priority is not used, all interrupts may use the Fast Register Stack for returns from interrupt. If no interrupts are used, the Fast Register Stack can be used to restore the STATUS, WREG and BSR registers at the end of a subroutine call. To use the Fast Register Stack for a subroutine call, a CALL label, FAST instruction must be executed to save the STATUS, WREG and BSR registers to the Fast Register Stack. A RETURN, FAST instruction is then executed to restore these registers from the Fast Register Stack. EXAMPLE 6-2: Example 6-1 shows a source code example that uses the Fast Register Stack during a subroutine call and return. EXAMPLE 6-1: CALL SUB1, FAST FAST REGISTER STACK CODE EXAMPLE ;STATUS, WREG, BSR ;SAVED IN FAST REGISTER ;STACK RETURN FAST SUB1 ;RESTORE VALUES SAVED ;IN FAST REGISTER STACK 2010 Microchip Technology Inc. In this method, only one data byte may be stored in each instruction location and room on the return address stack is required. ORG TABLE 6.1.6.2 MOVF CALL nn00h ADDWF RETLW RETLW RETLW . . . COMPUTED GOTO USING AN OFFSET VALUE OFFSET, W TABLE PCL nnh nnh nnh Table Reads A better method of storing data in program memory allows two bytes of data to be stored in each instruction location. Look-up table data may be stored two bytes per program word while programming. The Table Pointer (TBLPTR) specifies the byte address and the Table Latch (TABLAT) contains the data that is read from the program memory. Data is transferred from program memory one byte at a time. Table read operation is discussed further Section 7.1 "Table Reads and Table Writes". in DS39770C-page 67 PIC18F85J90 FAMILY 6.2 PIC18 Instruction Cycle 6.2.1 6.2.2 An "Instruction Cycle" consists of four Q cycles, Q1 through Q4. The instruction fetch and execute are pipelined in such a manner that a fetch takes one instruction cycle, while the decode and execute take another instruction cycle. However, due to the pipelining, each instruction effectively executes in one cycle. If an instruction causes the program counter to change (e.g., GOTO), then two cycles are required to complete the instruction (Example 6-3). CLOCKING SCHEME The microcontroller clock input, whether from an internal or external source, is internally divided by four to generate four non-overlapping quadrature clocks (Q1, Q2, Q3 and Q4). Internally, the program counter is incremented on every Q1; the instruction is fetched from the program memory and latched into the Instruction Register (IR) during Q4. The instruction is decoded and executed during the following Q1 through Q4. The clocks and instruction execution flow are shown in Figure 6-4. FIGURE 6-4: INSTRUCTION FLOW/PIPELINING A fetch cycle begins with the Program Counter (PC) incrementing in Q1. In the execution cycle, the fetched instruction is latched into the Instruction Register (IR) in cycle Q1. This instruction is then decoded and executed during the Q2, Q3 and Q4 cycles. Data memory is read during Q2 (operand read) and written during Q4 (destination write). CLOCK/INSTRUCTION CYCLE Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 OSC1 Q1 Q2 Internal Phase Clock Q3 Q4 PC PC PC + 2 PC + 4 OSC2/CLKO (RC mode) Execute INST (PC - 2) Fetch INST (PC) EXAMPLE 6-3: 1. MOVLW 55h 4. BSF Execute INST (PC + 2) Fetch INST (PC + 4) INSTRUCTION PIPELINE FLOW TCY 0 TCY 1 Fetch 1 Execute 1 2. MOVWF PORTB 3. BRA Execute INST (PC) Fetch INST (PC + 2) SUB_1 PORTA, BIT3 (Forced NOP) 5. Instruction @ address SUB_1 Fetch 2 TCY 2 TCY 3 TCY 4 TCY 5 Execute 2 Fetch 3 Execute 3 Fetch 4 Flush (NOP) Fetch SUB_1 Execute SUB_1 All instructions are single cycle, except for any program branches. These take two cycles since the fetch instruction is "flushed" from the pipeline while the new instruction is being fetched and then executed. DS39770C-page 68 2010 Microchip Technology Inc. PIC18F85J90 FAMILY 6.2.3 INSTRUCTIONS IN PROGRAM MEMORY The program memory is addressed in bytes. Instructions are stored as two bytes or four bytes in program memory. The Least Significant Byte of an instruction word is always stored in a program memory location with an even address (LSB = 0). To maintain alignment with instruction boundaries, the PC increments in steps of 2 and the LSB will always read `0' (see Section 6.1.3 "Program Counter"). Figure 6-5 shows an example of how instruction words are stored in the program memory. FIGURE 6-5: The CALL and GOTO instructions have the absolute program memory address embedded into the instruction. Since instructions are always stored on word boundaries, the data contained in the instruction is a word address. The word address is written to PC<20:1> which accesses the desired byte address in program memory. Instruction #2 in Figure 6-5 shows how the instruction, GOTO 0006h, is encoded in the program memory. Program branch instructions, which encode a relative address offset, operate in the same manner. The offset value stored in a branch instruction represents the number of single-word instructions that the PC will be offset by. Section 24.0 "Instruction Set Summary" provides further details of the instruction set. INSTRUCTIONS IN PROGRAM MEMORY LSB = 1 LSB = 0 0Fh EFh F0h C1h F4h 55h 03h 00h 23h 56h Program Memory Byte Locations 6.2.4 Instruction 1: Instruction 2: MOVLW GOTO 055h 0006h Instruction 3: MOVFF 123h, 456h TWO-WORD INSTRUCTIONS The standard PIC18 instruction set has four, two-word instructions: CALL, MOVFF, GOTO and LSFR. In all cases, the second word of the instructions always has `1111' as its four Most Significant bits; the other 12 bits are literal data, usually a data memory address. The use of `1111' in the 4 MSbs of an instruction specifies a special form of NOP. If the instruction is executed in proper sequence - immediately after the first word - the data in the second word is accessed EXAMPLE 6-4: Word Address 000000h 000002h 000004h 000006h 000008h 00000Ah 00000Ch 00000Eh 000010h 000012h 000014h and used by the instruction sequence. If the first word is skipped for some reason and the second word is executed by itself, a NOP is executed instead. This is necessary for cases when the two-word instruction is preceded by a conditional instruction that changes the PC. Example 6-4 shows how this works. Note: See Section 6.5 "Program Memory and the Extended Instruction Set" for information on two-word instructions in the extended instruction set. TWO-WORD INSTRUCTIONS CASE 1: Object Code Source Code 0110 0110 0000 0000 TSTFSZ REG1 ; is RAM location 0? 1100 0001 0010 0011 MOVFF REG1, REG2 ; No, skip this word ADDWF REG3 ; continue code 1111 0100 0101 0110 0010 0100 0000 0000 ; Execute this word as a NOP CASE 2: Object Code Source Code 0110 0110 0000 0000 TSTFSZ REG1 ; is RAM location 0? 1100 0001 0010 0011 MOVFF REG1, REG2 ; Yes, execute this word ADDWF REG3 ; continue code 1111 0100 0101 0110 0010 0100 0000 0000 2010 Microchip Technology Inc. ; 2nd word of instruction DS39770C-page 69 PIC18F85J90 FAMILY 6.3 Note: Data Memory Organization The operation of some aspects of data memory are changed when the PIC18 extended instruction set is enabled. See Section 6.6 "Data Memory and the Extended Instruction Set" for more information. The data memory in PIC18 devices is implemented as static RAM. Each register in the data memory has a 12-bit address, allowing up to 4096 bytes of data memory. The memory space is divided into as many as 16 banks that contain 256 bytes each. The PIC18FX3J90/X4J90 devices, with up to 16 Kbytes of program memory, implement 4 complete banks for a total of 1024 bytes. PIC18FX5J90 devices, with 32 Kbytes of program memory, implement 8 complete banks for a total of 2048 bytes. Figure 6-6 and Figure 6-7 show the data memory organization for the devices. The data memory contains Special Function Registers (SFRs) and General Purpose Registers (GPRs). The SFRs are used for control and status of the controller and peripheral functions, while GPRs are used for data storage and scratchpad operations in the user's application. Any read of an unimplemented location will read as `0's. 6.3.1 BANK SELECT REGISTER Large areas of data memory require an efficient addressing scheme to make rapid access to any address possible. Ideally, this means that an entire address does not need to be provided for each read or write operation. For PIC18 devices, this is accomplished with a RAM banking scheme. This divides the memory space into 16 contiguous banks of 256 bytes. Depending on the instruction, each location can be addressed directly by its full 12-bit address, or an 8-bit low-order address and a 4-bit Bank Pointer. Most instructions in the PIC18 instruction set make use of the Bank Pointer, known as the Bank Select Register (BSR). This SFR holds the 4 Most Significant bits (MSbs) of a location's address; the instruction itself includes the 8 Least Significant bits (LSbs). Only the four lower bits of the BSR are implemented (BSR<3:0>). The upper four bits are unused; they will always read `0' and cannot be written to. The BSR can be loaded directly by using the MOVLB instruction. The value of the BSR indicates the bank in data memory. The 8 bits in the instruction show the location in the bank and can be thought of as an offset from the bank's lower boundary. The relationship between the BSR's value and the bank division in data memory is shown in Figure 6-8. The instruction set and architecture allow operations across all banks. The entire data memory may be accessed by Direct, Indirect or Indexed Addressing modes. Addressing modes are discussed later in this section. Since up to 16 registers may share the same low-order address, the user must always be careful to ensure that the proper bank is selected before performing a data read or write. For example, writing what should be program data to an 8-bit address of F9h while the BSR is 0Fh, will end up resetting the program counter. To ensure that commonly used registers (select SFRs and select GPRs) can be accessed in a single cycle, PIC18 devices implement an Access Bank. This is a 256-byte memory space that provides fast access to select SFRs and the lower portion of GPR Bank 0 without using the BSR. Section 6.3.2 "Access Bank" provides a detailed description of the Access RAM. While any bank can be selected, only those banks that are actually implemented can be read or written to. Writes to unimplemented banks are ignored, while reads from unimplemented banks will return `0's. Even so, the STATUS register will still be affected as if the operation was successful. The data memory map in Figure 6-6 indicates which banks are implemented. In the core PIC18 instruction set, only the MOVFF instruction fully specifies the 12-bit address of the source and target registers. This instruction ignores the BSR completely when it executes. All other instructions include only the low-order address as an operand and must use either the BSR or the Access Bank to locate their target registers. DS39770C-page 70 2010 Microchip Technology Inc. PIC18F85J90 FAMILY FIGURE 6-6: DATA MEMORY MAP FOR PIC18FX3J90/X4J90 DEVICES When a = 0: BSR<3:0> Data Memory Map 00h = 0000 = 0001 = 0010 = 0011 Bank 0 FFh 00h Bank 1 Access RAM GPR GPR 1FFh 200h FFh 00h Bank 2 GPR FFh 00h Bank 3 2FFh 300h GPR FFh 00h = 0100 000h 05Fh 060h 0FFh 100h The BSR is ignored and the Access Bank is used. The first 96 bytes are general purpose RAM (from Bank 0). The second 160 bytes are Special Function Registers (from Bank 15). When a = 1: The BSR specifies the bank used by the instruction. 3FFh 400h Bank 4 Access Bank Access RAM Low = 1110 = 1111 5Fh Access RAM High 60h (SFRs) FFh Unused Read as `0' to 00h Bank 14 FFh 00h Unused FFh SFR Bank 15 2010 Microchip Technology Inc. EFFh F00h F5Fh F60h FFFh DS39770C-page 71 PIC18F85J90 FAMILY FIGURE 6-7: DATA MEMORY MAP FOR PIC18FX5J90 DEVICES When a = 0: BSR<3:0> Data Memory Map 00h = 0000 = 0001 = 0010 = 0011 = 0100 = 0101 = 0110 = 0111 Bank 0 FFh 00h Bank 1 Access RAM GPR GPR 1FFh 200h FFh 00h Bank 2 GPR FFh 00h Bank 3 2FFh 300h GPR FFh 00h Bank 4 = 1111 DS39770C-page 72 The second 160 bytes are Special Function Registers (from Bank 15). When a = 1: The BSR specifies the bank used by the instruction. 3FFh 400h 4FFh 500h GPR Bank 5 FFh 00h 5FFh 600h GPR Bank 6 FFh 00h 6FFh 700h GPR Bank 7 7FFh 800h Access Bank Access RAM Low 00h 5Fh Access RAM High 60h (SFRs) FFh Bank 8 Unused Read as `0' to = 1110 The first 96 bytes are general purpose RAM (from Bank 0). GPR FFh 00h FFh 00h = 1000 000h 05Fh 060h 0FFh 100h The BSR is ignored and the Access Bank is used. Bank 14 FFh 00h Unused FFh SFR Bank 15 EFFh F00h F5Fh F60h FFFh 2010 Microchip Technology Inc. PIC18F85J90 FAMILY FIGURE 6-8: USE OF THE BANK SELECT REGISTER (DIRECT ADDRESSING) BSR(1) 7 0 0 0 0 0 0 0 Bank Select(2) 1 0 000h Data Memory Bank 0 100h Bank 1 200h 300h Bank 2 00h 7 FFh 00h 1 From Opcode(2) 1 11 1 11 1 0 11 11 FFh 00h FFh 00h Bank 3 through Bank 13 E00h Bank 14 F00h FFFh Note 1: 2: 6.3.2 Bank 15 FFh 00h FFh 00h FFh The Access RAM bit of the instruction can be used to force an override of the selected bank (BSR<3:0>) to the registers of the Access Bank. The MOVFF instruction embeds the entire 12-bit address in the instruction. ACCESS BANK While the use of the BSR with an embedded 8-bit address allows users to address the entire range of data memory, it also means that the user must always ensure that the correct bank is selected. Otherwise, data may be read from, or written to, the wrong location. This can be disastrous if a GPR is the intended target of an operation, but an SFR is written to instead. Verifying and/or changing the BSR for each read or write to data memory can become very inefficient. To streamline access for the most commonly used data memory locations, the data memory is configured with an Access Bank, which allows users to access a mapped block of memory without specifying a BSR. The Access Bank consists of the first 96 bytes of memory (00h-5Fh) in Bank 0 and the last 160 bytes of memory (60h-FFh) in Bank 15. The lower half is known as the "Access RAM" and is composed of GPRs. The upper half is where the device's SFRs are mapped. These two areas are mapped contiguously in the Access Bank and can be addressed in a linear fashion by an 8-bit address (Figure 6-6). The Access Bank is used by core PIC18 instructions that include the Access RAM bit (the `a' parameter in the instruction). When `a' is equal to `1', the instruction uses the BSR and the 8-bit address included in the opcode for the data memory address. When `a' is `0', 2010 Microchip Technology Inc. however, the instruction is forced to use the Access Bank address map; the current value of the BSR is ignored entirely. Using this "forced" addressing allows the instruction to operate on a data address in a single cycle without updating the BSR first. For 8-bit addresses of 60h and above, this means that users can evaluate and operate on SFRs more efficiently. The Access RAM below 60h is a good place for data values that the user might need to access rapidly, such as immediate computational results or common program variables. Access RAM also allows for faster and more code efficient context saving and switching of variables. The mapping of the Access Bank is slightly different when the extended instruction set is enabled (XINST Configuration bit = 1). This is discussed in more detail in Section 6.6.3 "Mapping the Access Bank in Indexed Literal Offset Mode". 6.3.3 GENERAL PURPOSE REGISTER FILE PIC18 devices may have banked memory in the GPR area. This is data RAM which is available for use by all instructions. GPRs start at the bottom of Bank 0 (address 000h) and grow upwards towards the bottom of the SFR area. GPRs are not initialized by a Power-on Reset and are unchanged on all other Resets. DS39770C-page 73 PIC18F85J90 FAMILY 6.3.4 SPECIAL FUNCTION REGISTERS The Special Function Registers (SFRs) are registers used by the CPU and peripheral modules for controlling the desired operation of the device. These registers are implemented as static RAM. SFRs start at the top of data memory (FFFh) and extend downward to occupy more than the top half of Bank 15 (F60h to FFFh). A list of these registers is given in Table 6-2 and Table 6-3. TABLE 6-2: Address The SFRs can be classified into two sets: those associated with the "core" device functionality (ALU, Resets and interrupts) and those related to the peripheral functions. The Reset and Interrupt registers are described in their respective chapters, while the ALU's STATUS register is described later in this section. Registers related to the operation of the peripheral features are described in the chapter for that peripheral. The SFRs are typically distributed among the peripherals whose functions they control. Unused SFR locations are unimplemented and read as `0's. SPECIAL FUNCTION REGISTER MAP FOR PIC18F85J90 FAMILY DEVICES Name Address Name Name Address (3) Name Address Name FFFh TOSU FDFh F9Fh IPR1 F7Fh SPBRGH1 FFEh TOSH FDEh POSTINC2(1) FBEh LCDDATA3 F9Eh PIR1 F7Eh BAUDCON1 FFDh TOSL FDDh POSTDEC2(1) FBDh LCDDATA2 F9Dh PIE1 F7Dh LCDDATA23(3) (2) F7Ch LCDDATA22(3) FFCh STKPTR INDF2 Address (1) (1) FBFh LCDDATA4 FDCh PREINC2 FBCh LCDDATA1 F9Ch -- FFBh PCLATU FDBh PLUSW2(1) FBBh LCDDATA0 F9Bh OSCTUNE F7Bh LCDDATA21 FFAh PCLATH FDAh FSR2H FBAh LCDSE5(3) F9Ah TRISJ(3) F7Ah LCDDATA20 FF9h PCL FD9h FSR2L FB9h LCDSE4(3) F99h TRISH(3) F79h LCDDATA19 FF8h TBLPTRU FD8h STATUS FB8h LCDSE3 F98h TRISG F78h LCDDATA18 FF7h TBLPTRH FD7h TMR0H FB7h LCDSE2 F97h TRISF F77h LCDDATA17(3) FF6h TBLPTRL FD6h TMR0L FB6h LCDSE1 F96h TRISE F76h LCDDATA16(3) FF5h TABLAT FD5h T0CON FB5h CVRCON F95h TRISD F75h LCDDATA15 -- (2) FF4h PRODH FD4h FB4h CMCON F94h TRISC F74h LCDDATA14 FF3h PRODL FD3h OSCCON FB3h TMR3H F93h TRISB F73h LCDDATA13 FF2h INTCON FD2h LCDREG FB2h TMR3L F92h TRISA F72h LCDDATA12 FF1h INTCON2 FD1h WDTCON FB1h T3CON F91h LATJ(3) F71h LCDDATA11(3) FF0h INTCON3 FD0h RCON FB0h --(2) F90h LATH(3) F70h LCDDATA10(3) FEFh INDF0(1) FCFh TMR1H FAFh SPBRG1 F8Fh LATG F6Fh LCDDATA9 FEEh POSTINC0(1) FCEh TMR1L FAEh RCREG1 F8Eh LATF F6Eh LCDDATA8 FEDh POSTDEC0(1) TXREG1 F8Dh LATE F6Dh LCDDATA7 FCDh T1CON FADh FECh PREINC0(1) FCCh TMR2 FACh TXSTA1 F8Ch LATD F6Ch LCDDATA6 FEBh PLUSW0(1) FCBh PR2 FABh RCSTA1 F8Bh LATC F6Bh LCDDATA5(3) FEAh FSR0H FCAh T2CON FAAh LCDPS F8Ah LATB F6Ah CCPR1H FE9h FSR0L FC9h SSPBUF FA9h LCDSE0 F89h LATA F69h CCPR1L (3) FE8h WREG FC8h SSPADD FA8h LCDCON F88h PORTJ F68h CCP1CON FE7h INDF1(1) FC7h SSPSTAT FA7h EECON2 F87h PORTH(3) F67h CCPR2H FE6h POSTINC1(1) FC6h SSPCON1 FA6h EECON1 F86h PORTG F66h CCPR2L FE5h POSTDEC1(1) FC5h SSPCON2 FA5h IPR3 F85h PORTF F65h CCP2CON FE4h PREINC1(1) FC4h ADRESH FA4h PIR3 F84h PORTE F64h SPBRG2 FE3h PLUSW1(1) FC3h ADRESL FA3h PIE3 F83h PORTD F63h RCREG2 FE2h FSR1H FC2h ADCON0 FA2h IPR2 F82h PORTC F62h TXREG2 FE1h FSR1L FC1h ADCON1 FA1h PIR2 F81h PORTB F61h TXSTA2 FE0h BSR FC0h ADCON2 FA0h PIE2 F80h PORTA F60h RCSTA2 Note 1: 2: 3: This is not a physical register. Unimplemented registers are read as `0'. This register is not available on 64-pin devices. DS39770C-page 74 2010 Microchip Technology Inc. PIC18F85J90 FAMILY TABLE 6-3: File Name PIC18F85J90 FAMILY REGISTER FILE SUMMARY Bit 7 Bit 6 Bit 5 -- -- -- Bit 4 Bit 3 Bit 2 Bit 1 Bit 0 Details on page ---0 0000 57, 65 TOSH Top-of-Stack High Byte (TOS<15:8>) 0000 0000 57, 65 TOSL Top-of-Stack Low Byte (TOS<7:0>) 0000 0000 57, 65 Return Stack Pointer uu-0 0000 57, 66 Holding Register for PC<20:16> TOSU STKPTR STKFUL STKUNF -- PCLATU -- -- bit 21(1) Top-of-Stack Upper Byte (TOS<20:16>) Value on POR, BOR ---0 0000 57, 65 PCLATH Holding Register for PC<15:8> 0000 0000 57, 65 PCL PC Low Byte (PC<7:0>) 0000 0000 57, 65 --00 0000 57, 90 TBLPTRU -- -- bit 21 Program Memory Table Pointer Upper Byte (TBLPTR<20:16>) TBLPTRH Program Memory Table Pointer High Byte (TBLPTR<15:8>) 0000 0000 57, 90 TBLPTRL Program Memory Table Pointer Low Byte (TBLPTR<7:0>) 0000 0000 57, 90 TABLAT Program Memory Table Latch 0000 0000 57, 90 PRODH Product Register High Byte xxxx xxxx 57, 97 PRODL Product Register Low Byte xxxx xxxx 57, 97 RBIF 0000 000x 57, 101 INTCON GIE/GIEH PEIE/GIEL TMR0IE INT0IE RBIE TMR0IF INT0IF INTCON2 RBPU INTEDG0 INTEDG1 INTEDG2 INTEDG3 TMR0IP INT3IP RBIP 1111 1111 57, 102 INTCON3 INT2IP INT1IP INT3IE INT2IE INT1IE INT3IF INT2IF INT1IF 1100 0000 57, 103 INDF0 Uses contents of FSR0 to address data memory - value of FSR0 not changed (not a physical register) N/A 57, 81 POSTINC0 Uses contents of FSR0 to address data memory - value of FSR0 post-incremented (not a physical register) N/A 57, 82 POSTDEC0 Uses contents of FSR0 to address data memory - value of FSR0 post-decremented (not a physical register) N/A 57, 82 PREINC0 Uses contents of FSR0 to address data memory - value of FSR0 pre-incremented (not a physical register) N/A 57, 82 PLUSW0 Uses contents of FSR0 to address data memory - value of FSR0 pre-incremented (not a physical register) - value of FSR0 offset by W N/A 57, 82 FSR0H ---- xxxx 57, 81 FSR0L Indirect Data Memory Address Pointer 0 Low Byte -- xxxx xxxx 57, 81 WREG Working Register xxxx xxxx 57 INDF1 Uses contents of FSR1 to address data memory - value of FSR1 not changed (not a physical register) N/A 57, 81 POSTINC1 Uses contents of FSR1 to address data memory - value of FSR1 post-incremented (not a physical register) N/A 57, 82 POSTDEC1 Uses contents of FSR1 to address data memory - value of FSR1 post-decremented (not a physical register) N/A 57, 82 PREINC1 Uses contents of FSR1 to address data memory - value of FSR1 pre-incremented (not a physical register) N/A 57, 82 PLUSW1 Uses contents of FSR1 to address data memory - value of FSR1 pre-incremented (not a physical register) - value of FSR1 offset by W N/A 57, 82 ---- xxxx 58, 81 xxxx xxxx 58, 81 ---- 0000 58, 70 FSR1H -- FSR1L -- -- -- -- -- -- Indirect Data Memory Address Pointer 0 High Indirect Data Memory Address Pointer 1 High Byte Indirect Data Memory Address Pointer 1 Low Byte BSR -- -- -- -- Bank Select Register INDF2 Uses contents of FSR2 to address data memory - value of FSR2 not changed (not a physical register) N/A 58, 81 POSTINC2 Uses contents of FSR2 to address data memory - value of FSR2 post-incremented (not a physical register) N/A 58, 82 POSTDEC2 Uses contents of FSR2 to address data memory - value of FSR2 post-decremented (not a physical register) N/A 58, 82 PREINC2 Uses contents of FSR2 to address data memory - value of FSR2 pre-incremented (not a physical register) N/A 58, 82 PLUSW2 Uses contents of FSR2 to address data memory - value of FSR2 pre-incremented (not a physical register) - value of FSR2 offset by W N/A 58, 82 ---- xxxx 58, 81 xxxx xxxx 58, 81 ---x xxxx 58, 79 FSR2H FSR2L STATUS Legend: Note 1: 2: 3: 4: 5: -- -- -- -- Indirect Data Memory Address Pointer 2 High Byte Indirect Data Memory Address Pointer 2 Low Byte -- -- -- N OV Z DC C x = unknown, u = unchanged, - = unimplemented, q = value depends on condition, r = reserved, do not modify Bit 21 of the PC is only available in Test mode and Serial Programming modes. These registers and/or bits are available only on 80-pin devices; otherwise, they are unimplemented and read as `0'. Reset states shown are for 80-pin devices. Alternate names and definitions for these bits when the MSSP module is operating in I2CTM Slave mode. See Section 17.4.3.2 "Address Masking" for details. The PLLEN bit is only available in specific oscillator configurations; otherwise, it is disabled and reads as `0'. See Section 3.4.3 "PLL Frequency Multiplier" for details. RA6/RA7 and their associated latch and direction bits are configured as port pins only when the internal oscillator is selected as the default clock source (FOSC2 Configuration bit = 0); otherwise, they are disabled and these bits read as `0'. 2010 Microchip Technology Inc. DS39770C-page 75 PIC18F85J90 FAMILY TABLE 6-3: File Name PIC18F85J90 FAMILY REGISTER FILE SUMMARY (CONTINUED) Bit 7 Bit 6 Bit 5 Bit 4 Bit 3 Bit 2 Bit 1 Bit 0 Value on POR, BOR Details on page TMR0H Timer0 Register High Byte 0000 0000 58, 139 TMR0L Timer0 Register Low Byte xxxx xxxx 58, 139 58, 137 TMR0ON T08BIT T0CS T0SE PSA T0PS2 T0PS1 T0PS0 1111 1111 OSCCON T0CON IDLEN IRCF2 IRCF1 IRCF0 OSTS IOFS SCS1 SCS0 0100 q000 36, 58 LCDREG -- CPEN BIAS2 BIAS1 BIAS0 MODE13 CKSEL1 CKSEL0 -011 1100 58, 169 WDTCON REGSLP -- -- -- -- -- -- SWDTEN 0--- ---0 58, 298 IPEN -- CM RI TO PD POR BOR 0-11 11q0 52, 58 xxxx xxxx 58, 145 xxxx xxxx 58, 145 RCON TMR1H Timer1 Register High Byte TMR1L Timer1 Register Low Byte T1CON RD16 T1RUN TMR2 Timer2 Register PR2 Timer2 Period Register T2CON -- T1CKPS1 T1CKPS0 T1OSCEN T2OUTPS3 T2OUTPS2 T2OUTPS1 T2OUTPS0 T1SYNC TMR2ON TMR1CS T2CKPS1 TMR1ON T2CKPS0 SSPBUF MSSP Receive Buffer/Transmit Register SSPADD MSSP Address Register in I2CTM Slave mode. MSSP1 Baud Rate Reload Register in I2C Master mode. 0000 0000 58, 141 0000 0000 58, 148 1111 1111 58, 148 -000 0000 58, 147 xxxx xxxx 58, 199, 234 0000 0000 58, 234 SSPSTAT SMP CKE D/A P S R/W UA BF 0000 0000 58, 192, 201 SSPCON1 WCOL SSPOV SSPEN CKP SSPM3 SSPM2 SSPM1 SSPM0 0000 0000 58, 193, 202 SSPCON2 GCEN ACKSTAT ACKDT ACKEN RCEN PEN RSEN SEN 0000 0000 GCEN ACKSTAT 58, 203, 204 ADMSK5(3) ADMSK4(3) ADMSK3(3) ADMSK2(3) ADMSK1(3) SEN ADRESH A/D Result Register High Byte xxxx xxxx 59, 279 ADRESL A/D Result Register Low Byte xxxx xxxx 59, 279 ADCON0 ADCAL -- CHS3 CHS2 CHS1 CHS0 GO/DONE ADON 0-00 0000 59, 271 ADCON1 -- -- VCFG1 VCFG0 PCFG3 PCFG2 PCFG1 PCFG0 --00 0000 59, 272 59, 273 ADCON2 ADFM -- ACQT2 ACQT1 ACQT0 ADCS2 ADCS1 ADCS0 0-00 0000 LCDDATA4 S39C0(2) S38C0(2) S37C0(2) S36C0(2) S35C0(2) S34C0(2) S33C0(2) S32C0 xxxx xxxx 59, 167 LCDDATA3 S31C0 S30C0 S29C0 S28C0 S27C0 S26C0 S25C0 S24C0 xxxx xxxx 59, 167 LCDDATA2 S23C0 S22C0 S21C0 S20C0 S19C0 S18C0 S17C0 S16C0 xxxx xxxx 59, 167 LCDDATA1 S15C0 S14C0 S13C0 S12C0 S11C0 S10C0 S09C0 S08C0 xxxx xxxx 59, 167 LCDDATA0 S07C0 S06C0 S05C0 S04C0 S03C0 S02C0 S01C0 S00C0 xxxx xxxx 59, 167 LCDSE5(2) SE47 SE46 SE45 SE44 SE43 SE42 SE41 SE40 0000 0000 59, 166 LCDSE4 SE39(2) SE38(2) S37(2) SE36(2) SE35(2) SE34(2) SE33(2) SE32 0000 0000 59, 166 LCDSE3 SE31 SE30 SE29 SE28 SE27 SE26 SE25 SE24 0000 0000 59, 166 LCDSE2 SE23 SE22 SE21 SE20 SE19 SE18 SE17 SE16 0000 0000 59, 166 LCDSE1 SE15 SE14 SE13 SE12 SE11 SE10 SE09 SE08 0000 0000 59, 166 CVRCON CVREN CVROE CVRR CVRSS CVR3 CVR2 CVR1 CVR0 0000 0000 59, 287 CMCON C2OUT C1OUT C2INV C1INV CIS CM2 CM1 CM0 0000 0111 59, 281 TMR3H Timer3 Register High Byte xxxx xxxx 59, 151 TMR3L Timer3 Register Low Byte xxxx xxxx 59, 151 0000 0000 59, 149 T3CON Legend: Note 1: 2: 3: 4: 5: RD16 T3CCP2 T3CKPS1 T3CKPS0 T3CCP1 T3SYNC TMR3CS TMR3ON x = unknown, u = unchanged, - = unimplemented, q = value depends on condition, r = reserved, do not modify Bit 21 of the PC is only available in Test mode and Serial Programming modes. These registers and/or bits are available only on 80-pin devices; otherwise, they are unimplemented and read as `0'. Reset states shown are for 80-pin devices. Alternate names and definitions for these bits when the MSSP module is operating in I2CTM Slave mode. See Section 17.4.3.2 "Address Masking" for details. The PLLEN bit is only available in specific oscillator configurations; otherwise, it is disabled and reads as `0'. See Section 3.4.3 "PLL Frequency Multiplier" for details. RA6/RA7 and their associated latch and direction bits are configured as port pins only when the internal oscillator is selected as the default clock source (FOSC2 Configuration bit = 0); otherwise, they are disabled and these bits read as `0'. DS39770C-page 76 2010 Microchip Technology Inc. PIC18F85J90 FAMILY TABLE 6-3: File Name PIC18F85J90 FAMILY REGISTER FILE SUMMARY (CONTINUED) Bit 7 Bit 6 Bit 5 Bit 4 Bit 3 Bit 2 Bit 1 Bit 0 Value on POR, BOR Details on page SPBRG1 EUSART Baud Rate Generator 0000 0000 59, 240 RCREG1 EUSART Receive Register 0000 0000 59, 248 TXREG1 EUSART Transmit Register 0000 0000 59, 246 TXSTA1 CSRC TX9 TXEN SYNC SENDB BRGH TRMT TX9D 0000 0010 59, 236 RCSTA1 SPEN RX9 SREN CREN ADDEN FERR OERR RX9D 0000 000x 59, 237 LCDPS WFT BIASMD LCDA WA LP3 LP2 LP1 LP0 0000 0000 59, 165 LCDSE0 SE07 SE06 SE05 SE04 SE03 SE02 SE01 SE00 0000 0000 59, 166 LCDCON LCDEN SLPEN WERR -- CS1 CS0 LMUX1 LMUX0 000- 0000 59, 164 ---- ---- 59, 88 EECON2 EEPROM Control Register 2 (not a physical register) EECON1 -- -- -- FREE WRERR WREN WR -- ---0 x00- 59, 89 IPR3 -- LCDIP RC2IP TX2IP -- CCP2IP CCP1IP -- -111 -11- 60, 112 PIR3 -- LCDIF RC2IF TX2IF -- CCP2IF CCP1IF -- -000 -00- 60, 106 PIE3 -- LCDIE RC2IE TX2IE -- CCP2IE CCP1IE -- -000 -00- 60, 109 IPR2 OSCFIP CMIP -- -- BCLIP LVDIP TMR3IP -- 11-- 111- 60, 111 PIR2 OSCFIF CMIF -- -- BCLIF LVDIF TMR3IF -- 00-- 000- 60, 105 PIE2 OSCFIE CMIE -- -- BCLIE LVDIE TMR3IE -- 00-- 000- 60, 108 IPR1 -- ADIP RC1IP TX1IP SSPIP -- TMR2IP TMR1IP -111 1-11 60, 110 PIR1 -- ADIF RC1IF TX1IF SSPIF -- TMR2IF TMR1IF -000 0-00 60, 104 60, 107 PIE1 -- ADIE RC1IE TX1IE SSPIE -- TMR2IE TMR1IE -000 0-00 OSCTUNE INTSRC PLLEN(4) TUN5 TUN4 TUN3 TUN2 TUN1 TUN0 0000 0000 37, 60 TRISJ(2) TRISJ7 TRISJ6 TRISJ5 TRISJ4 TRISJ3 TRISJ2 TRISJ1 TRISJ0 1111 1111 60, 136 TRISH(2) TRISH7 TRISH6 TRISH5 TRISH4 TRISH3 TRISH2 TRISH1 TRISH0 1111 1111 60, 134 TRISG SPIOD CCP2OD CCP1OD TRISG4 TRISG3 TRISG2 TRISG1 TRISG0 0001 1111 60, 132 TRISF TRISF7 TRISF6 TRISF5 TRISF4 TRISF3 TRISF2 TRISF1 -- 1111 111- 60, 130 TRISE TRISE7 TRISE6 TRISE5 TRISE4 TRISE3 -- TRISE1 TRISE0 1111 1-11 60, 127 TRISD TRISD7 TRISD6 TRISD5 TRISD4 TRISD3 TRISD2 TRISD1 TRISD0 1111 1111 60, 125 TRISC TRISC7 TRISC6 TRISC5 TRISC4 TRISC3 TRISC2 TRISC1 TRISC0 1111 1111 60, 123 TRISB TRISB7 TRISB6 TRISB5 TRISB4 TRISB3 TRISB2 TRISB1 TRISB0 1111 1111 60, 120 TRISA TRISA7(5) TRISA6(5) TRISA5 TRISA4 TRISA3 TRISA2 TRISA1 TRISA0 1111 1111 60, 117 LATJ(2) LATJ7 LATJ6 LATJ5 LATJ4 LATJ3 LATJ2 LATJ1 LATJ0 xxxx xxxx 60, 136 LATH(2) LATH7 LATH6 LATH5 LATH4 LATH3 LATH2 LATH1 LATH0 xxxx xxxx 60, 134 LATG U2OD U1OD -- LATG4 LATG3 LATG2 LATG1 LATG0 00-x xxxx 60, 132 LATF LATF7 LATF6 LATF5 LATF4 LATF3 LATF2 LATF1 -- xxxx xxx- 60, 130 LATE LATE7 LATE6 LATE5 LATE4 LATE3 -- LATE1 LATE0 xxxx x-xx 60, 127 LATD LATD7 LATD6 LATD5 LATD4 LATD3 LATD2 LATD1 LATD0 xxxx xxxx 60, 125 LATC LATC7 LATC6 LATC5 LATC4 LATC3 LATC2 LATC1 LATC0 xxxx xxxx 60, 123 LATB LATB7 LATB6 LATB5 LATB4 LATB3 LATB2 LATB1 LATB0 xxxx xxxx 60, 120 LATA LATA7(5) LATA6(5) LATA5 LATA4 LATA3 LATA2 LATA1 LATA0 xxxx xxxx 60, 117 Legend: Note 1: 2: 3: 4: 5: x = unknown, u = unchanged, - = unimplemented, q = value depends on condition, r = reserved, do not modify Bit 21 of the PC is only available in Test mode and Serial Programming modes. These registers and/or bits are available only on 80-pin devices; otherwise, they are unimplemented and read as `0'. Reset states shown are for 80-pin devices. Alternate names and definitions for these bits when the MSSP module is operating in I2CTM Slave mode. See Section 17.4.3.2 "Address Masking" for details. The PLLEN bit is only available in specific oscillator configurations; otherwise, it is disabled and reads as `0'. See Section 3.4.3 "PLL Frequency Multiplier" for details. RA6/RA7 and their associated latch and direction bits are configured as port pins only when the internal oscillator is selected as the default clock source (FOSC2 Configuration bit = 0); otherwise, they are disabled and these bits read as `0'. 2010 Microchip Technology Inc. DS39770C-page 77 PIC18F85J90 FAMILY TABLE 6-3: File Name PIC18F85J90 FAMILY REGISTER FILE SUMMARY (CONTINUED) Bit 7 Bit 6 Bit 5 Bit 4 Bit 3 Bit 2 Bit 1 Bit 0 Value on POR, BOR Details on page 60, 136 PORTJ(2) RJ7 RJ6 RJ5 RJ4 RJ3 RJ2 RJ1 RJ0 xxxx xxxx PORTH(2) RH7 RH6 RH5 RH4 RH3 RH2 RH1 RH0 xxxx xxxx 60, 134 RDPU REPU RJPU(2) RG4 RG3 RG2 RG1 RG0 000x xxxx 60, 132 60, 130 PORTG PORTF RF7 RF6 RF5 RF4 RF3 RF2 RF1 -- xxxx xxx- PORTE RE7 RE6 RE5 RE4 RE3 -- RE1 RE0 xxxx x-xx 61, 127 PORTD RD7 RD6 RD5 RD4 RD3 RD2 RD1 RD0 xxxx xxxx 61, 125 PORTC RC7 RC6 RC5 RC4 RC3 RC2 RC1 RC0 xxxx xxxx 61, 123 PORTB RB7 RB6 RB5 RB4 RB3 RB2 RB1 RB0 xxxx xxxx 61, 120 PORTA RA7(5) RA6(5) RA5 RA4 RA3 RA2 RA1 RA0 xx0x 0000 61, 117 0000 0000 61, 240 SPBRGH1 EUSART Baud Rate Generator High Byte BAUDCON1 ABDOVF RCIDL RXDTP TXCKP BRG16 -- WUE ABDEN 0100 0-00 61, 238 S47C3 S46C3 S45C3 S44C3 S43C3 S42C3 S41C3 S40C3 xxxx xxxx 61, 167 LCDDATA22 S39C3(2) S38C3(2) S37C3(2) S36C3(2) S35C3(2) S34C3(2) S33C3(2) S32C3 xxxx xxxx 61, 167 LCDDATA21 S31C3 S30C3 S29C3 S28C3 S27C3 S26C3 S25C3 S24C3 xxxx xxxx 61, 167 LCDDATA23(2) LCDDATA20 S23C3 S22C3 S21C3 S20C3 S19C3 S18C3 S17C3 S16C3 xxxx xxxx 61, 167 LCDDATA19 S15C3 S14C3 S13C3 S12C3 S11C3 S10C3 S09C3 S08C3 xxxx xxxx 61, 167 LCDDATA18 S07C3 S06C3 S05C3 S04C3 S03C3 S02C3 S01C3 S00C3 xxxx xxxx 61, 167 LCDDATA17(2) S47C2 S46C2 S45C2 S44C2 S43C2 S42C2 S41C2 S40C2 xxxx xxxx 61, 167 LCDDATA16 S39C2(2) S38C2(2) S37C2(2) S36C2(2) S35C2(2) S34C2(2) S33C2(2) S32C2 xxxx xxxx 61, 167 LCDDATA15 S31C2 S30C2 S29C2 S28C2 S27C2 S26C2 S25C2 S24C2 xxxx xxxx 61, 167 LCDDATA14 S23C2 S22C2 S21C2 S20C2 S19C2 S18C2 S17C2 S16C2 xxxx xxxx 61, 167 LCDDATA13 S15C2 S14C2 S13C2 S12C2 S11C2 S10C2 S09C2 S08C2 xxxx xxxx 61, 167 LCDDATA12 S07C2 S06C2 S05C2 S04C2 S03C2 S02C2 S01C2 S00C2 xxxx xxxx 61, 167 LCDDATA11(2) S47C1 S46C1 S45C1 S44C1 S43C1 S42C1 S41C1 S40C1 xxxx xxxx 61, 167 LCDDATA10 S39C1(2) S38C1(2) S37C1(2) S36C1(2) S35C1(2) S34C1(2) S33C1(2) S32C1 xxxx xxxx 61, 167 LCDDATA9 S31C1 S30C1 S29C1 S28C1 S27C1 S26C1 S25C1 S24C1 xxxx xxxx 61, 167 LCDDATA8 S23C1 S22C1 S21C1 S20C1 S19C1 S18C1 S17C1 S16C1 xxxx xxxx 61, 167 LCDDATA7 S15C1 S14C1 S13C1 S12C1 S11C1 S10C1 S09C1 S08C1 xxxx xxxx 61, 167 61, 167 LCDDATA6 S07C1 S06C1 S05C1 S04C1 S03C1 S02C1 S01C1 S00C1 xxxx xxxx LCDDATA5(2) S47C0 S46C0 S45C0 S44C0 S43C0 S42C0 S41C0 S40C0 xxxx xxxx 61, 167 xxxx xxxx 61, 154 xxxx xxxx 61, 154 CCPR1H Capture/Compare/PWM Register 1 High Byte CCPR1L Capture/Compare/PWM Register 1 Low Byte CCP1CON -- -- DC1B1 DC1B0 CCPR2H Capture/Compare/PWM Register 2 High Byte CCPR2L Capture/Compare/PWM Register 2 Low Byte CCP2CON SPBRG2 -- -- DC2B1 DC2B0 CCP1M3 CCP2M3 CCP1M2 CCP2M2 CCP1M1 CCP2M1 CCP1M0 CCP2M0 AUSART Baud Rate Generator Register --00 0000 61, 153 xxxx xxxx 61, 154 xxxx xxxx 62, 154 --00 0000 62, 153 0000 0000 62, 260 RCREG2 AUSART Receive Register 0000 0000 62, 265 TXREG2 AUSART Transmit Register 0000 0000 62, 263 TXSTA2 CSRC TX9 TXEN SYNC -- BRGH TRMT TX9D 0000 -010 62, 258 RCSTA2 SPEN RX9 SREN CREN ADDEN FERR OERR RX9D 0000 000x 62, 259 Legend: Note 1: 2: 3: 4: 5: x = unknown, u = unchanged, - = unimplemented, q = value depends on condition, r = reserved, do not modify Bit 21 of the PC is only available in Test mode and Serial Programming modes. These registers and/or bits are available only on 80-pin devices; otherwise, they are unimplemented and read as `0'. Reset states shown are for 80-pin devices. Alternate names and definitions for these bits when the MSSP module is operating in I2CTM Slave mode. See Section 17.4.3.2 "Address Masking" for details. The PLLEN bit is only available in specific oscillator configurations; otherwise, it is disabled and reads as `0'. See Section 3.4.3 "PLL Frequency Multiplier" for details. RA6/RA7 and their associated latch and direction bits are configured as port pins only when the internal oscillator is selected as the default clock source (FOSC2 Configuration bit = 0); otherwise, they are disabled and these bits read as `0'. DS39770C-page 78 2010 Microchip Technology Inc. PIC18F85J90 FAMILY 6.3.5 STATUS REGISTER The STATUS register, shown in Register 6-2, contains the arithmetic status of the ALU. The STATUS register can be the operand for any instruction, as with any other register. If the STATUS register is the destination for an instruction that affects the Z, DC, C, OV or N bits, then the write to these five bits is disabled. These bits are set or cleared according to the device logic. Therefore, the result of an instruction with the STATUS register as destination may be different than intended. For example, CLRF STATUS will set the Z bit but leave the other bits unchanged. The STATUS REGISTER 6-2: U-0 For other instructions not affecting any Status bits, see the instruction set summaries in Table 24-2 and Table 24-3. Note: The C and DC bits operate as a borrow and digit borrow bit respectively, in subtraction. STATUS REGISTER U-0 -- register then reads back as `000u u1uu'. It is recommended, therefore, that only BCF, BSF, SWAPF, MOVFF and MOVWF instructions are used to alter the STATUS register because these instructions do not affect the Z, C, DC, OV or N bits in the STATUS register. U-0 -- -- R/W-x N R/W-x R/W-x R/W-x R/W-x Z DC(1) C(2) OV bit 7 bit 0 Legend: R = Readable bit W = Writable bit U = Unimplemented bit, read as `0' -n = Value at POR `1' = Bit is set `0' = Bit is cleared x = Bit is unknown bit 7-5 Unimplemented: Read as `0' bit 4 N: Negative bit This bit is used for signed arithmetic (2's complement). It indicates whether the result was negative (ALU MSB = 1). 1 = Result was negative 0 = Result was positive bit 3 OV: Overflow bit This bit is used for signed arithmetic (2's complement). It indicates an overflow of the 7-bit magnitude which causes the sign bit (bit 7) to change state. 1 = Overflow occurred for signed arithmetic (in this arithmetic operation) 0 = No overflow occurred bit 2 Z: Zero bit 1 = The result of an arithmetic or logic operation is zero 0 = The result of an arithmetic or logic operation is not zero bit 1 DC: Digit Carry/Borrow bit(1) For ADDWF, ADDLW, SUBLW and SUBWF instructions: 1 = A carry-out from the 4th low-order bit of the result occurred 0 = No carry-out from the 4th low-order bit of the result bit 0 C: Carry/Borrow bit(2) For ADDWF, ADDLW, SUBLW and SUBWF instructions: 1 = A carry-out from the Most Significant bit of the result occurred 0 = No carry-out from the Most Significant bit of the result occurred Note 1: 2: For borrow, the polarity is reversed. A subtraction is executed by adding the 2's complement of the second operand. For rotate (RRF, RLF) instructions, this bit is loaded with either bit 4 or bit 3 of the source register. For borrow, the polarity is reversed. A subtraction is executed by adding the 2's complement of the second operand. For rotate (RRF, RLF) instructions, this bit is loaded with either the high or low-order bit of the source register. 2010 Microchip Technology Inc. DS39770C-page 79 PIC18F85J90 FAMILY 6.4 Data Addressing Modes Note: The execution of some instructions in the core PIC18 instruction set are changed when the PIC18 extended instruction set is enabled. See Section 6.6 "Data Memory and the Extended Instruction Set" for more information. While the program memory can be addressed in only one way - through the program counter - information in the data memory space can be addressed in several ways. For most instructions, the addressing mode is fixed. Other instructions may use up to three modes, depending on which operands are used and whether or not the extended instruction set is enabled. The addressing modes are: * * * * Inherent Literal Direct Indirect INHERENT AND LITERAL ADDRESSING Many PIC18 control instructions do not need any argument at all; they either perform an operation that globally affects the device, or they operate implicitly on one register. This addressing mode is known as Inherent Addressing. Examples include SLEEP, RESET and DAW. Other instructions work in a similar way, but require an additional explicit argument in the opcode. This is known as Literal Addressing mode, because they require some literal value as an argument. Examples include ADDLW and MOVLW, which, respectively, add or move a literal value to the W register. Other examples include CALL and GOTO, which include a 20-bit program memory address. 6.4.2 A few instructions, such as MOVFF, include the entire 12-bit address (either source or destination) in their opcodes. In these cases, the BSR is ignored entirely. The destination of the operation's results is determined by the destination bit `d'. When `d' is `1', the results are stored back in the source register, overwriting its original contents. When `d' is `0', the results are stored in the W register. Instructions without the `d' argument have a destination that is implicit in the instruction; their destination is either the target register being operated on or the W register. 6.4.3 An additional addressing mode, Indexed Literal Offset, is available when the extended instruction set is enabled (XINST Configuration bit = 1). Its operation is discussed in greater detail in Section 6.6.1 "Indexed Addressing with Literal Offset". 6.4.1 The Access RAM bit `a' determines how the address is interpreted. When `a' is `1', the contents of the BSR (Section 6.3.1 "Bank Select Register") are used with the address to determine the complete 12-bit address of the register. When `a' is `0', the address is interpreted as being a register in the Access Bank. Addressing that uses the Access RAM is sometimes also known as Direct Forced Addressing mode. INDIRECT ADDRESSING Indirect Addressing allows the user to access a location in data memory without giving a fixed address in the instruction. This is done by using File Select Registers (FSRs) as pointers to the locations to be read or written to. Since the FSRs are themselves located in RAM as Special Function Registers, they can also be directly manipulated under program control. This makes FSRs very useful in implementing data structures such as tables and arrays in data memory. The registers for Indirect Addressing are also implemented with Indirect File Operands (INDFs) that permit automatic manipulation of the pointer value with auto-incrementing, auto-decrementing or offsetting with another value. This allows for efficient code using loops, such as the example of clearing an entire RAM bank in Example 6-5. It also enables users to perform Indexed Addressing and other Stack Pointer operations for program memory in data memory. EXAMPLE 6-5: DIRECT ADDRESSING LFSR CLRF Direct Addressing specifies all or part of the source and/or destination address of the operation within the opcode itself. The options are specified by the arguments accompanying the instruction. NEXT In the core PIC18 instruction set, bit-oriented and byte-oriented instructions use some version of Direct Addressing by default. All of these instructions include some 8-bit literal address as their Least Significant Byte. This address specifies either a register address in one of the banks of data RAM (Section 6.3.3 "General Purpose Register File"), or a location in the Access Bank (Section 6.3.2 "Access Bank") as the data source for the instruction. BRA CONTINUE DS39770C-page 80 BTFSS HOW TO CLEAR RAM (BANK 1) USING INDIRECT ADDRESSING FSR0, 100h ; POSTINC0 ; Clear INDF ; register then ; inc pointer FSR0H, 1 ; All done with ; Bank1? NEXT ; NO, clear next ; YES, continue 2010 Microchip Technology Inc. PIC18F85J90 FAMILY 6.4.3.1 FSR Registers and the INDF Operand the SFR space but are not physically implemented. Reading or writing to a particular INDF register actually accesses its corresponding FSR register pair. A read from INDF1, for example, reads the data at the address indicated by FSR1H:FSR1L. Instructions that use the INDF registers as operands actually use the contents of their corresponding FSR as a pointer to the instruction's target. The INDF operand is just a convenient way of using the pointer. At the core of Indirect Addressing are three sets of registers: FSR0, FSR1 and FSR2. Each represents a pair of 8-bit registers, FSRnH and FSRnL. The four upper bits of the FSRnH register are not used, so each FSR pair holds a 12-bit value. This represents a value that can address the entire range of the data memory in a linear fashion. The FSR register pairs, then, serve as pointers to data memory locations. Because Indirect Addressing uses a full 12-bit address, data RAM banking is not necessary. Thus, the current contents of the BSR and the Access RAM bit have no effect on determining the target address. Indirect Addressing is accomplished with a set of Indirect File Operands, INDF0 through INDF2. These can be thought of as "virtual" registers; they are mapped in FIGURE 6-9: INDIRECT ADDRESSING 000h Using an instruction with one of the Indirect Addressing registers as the operand.... Bank 0 ADDWF, INDF1, 1 100h Bank 1 200h ...uses the 12-bit address stored in the FSR pair associated with that register.... 300h FSR1H:FSR1L 7 0 x x x x 1 1 1 1 7 Bank 2 0 1 1 0 0 1 1 0 0 Bank 3 through Bank 13 ...to determine the data memory location to be used in that operation. In this case, the FSR1 pair contains FCCh. This means the contents of location FCCh will be added to that of the W register and stored back in FCCh. E00h Bank 14 F00h FFFh Bank 15 Data Memory 2010 Microchip Technology Inc. DS39770C-page 81 PIC18F85J90 FAMILY 6.4.3.2 FSR Registers and POSTINC, POSTDEC, PREINC and PLUSW In addition to the INDF operand, each FSR register pair also has four additional indirect operands. Like INDF, these are "virtual" registers that cannot be indirectly read or written to. Accessing these registers actually accesses the associated FSR register pair, but also performs a specific action on its stored value. They are: * POSTDEC: accesses the FSR value, then automatically decrements it by `1' afterwards * POSTINC: accesses the FSR value, then automatically increments it by `1' afterwards * PREINC: increments the FSR value by `1', then uses it in the operation * PLUSW: adds the signed value of the W register (range of -127 to 128) to that of the FSR and uses the new value in the operation In this context, accessing an INDF register uses the value in the FSR registers without changing them. Similarly, accessing a PLUSW register gives the FSR value offset by the value in the W register; neither value is actually changed in the operation. Accessing the other virtual registers changes the value of the FSR registers. Operations on the FSRs with POSTDEC, POSTINC and PREINC affect the entire register pair; that is, rollovers of the FSRnL register from FFh to 00h carry over to the FSRnH register. On the other hand, results of these operations do not change the value of any flags in the STATUS register (e.g., Z, N, OV, etc.). The PLUSW register can be used to implement a form of Indexed Addressing in the data memory space. By manipulating the value in the W register, users can reach addresses that are fixed offsets from pointer addresses. In some applications, this can be used to implement some powerful program control structure, such as software stacks, inside of data memory. DS39770C-page 82 6.4.3.3 Operations by FSRs on FSRs Indirect Addressing operations that target other FSRs or virtual registers represent special cases. For example, using an FSR to point to one of the virtual registers will not result in successful operations. As a specific case, assume that FSR0H:FSR0L contains FE7h, the address of INDF1. Attempts to read the value of the INDF1, using INDF0 as an operand, will return 00h. Attempts to write to INDF1, using INDF0 as the operand, will result in a NOP. On the other hand, using the virtual registers to write to an FSR pair may not occur as planned. In these cases, the value will be written to the FSR pair but without any incrementing or decrementing. Thus, writing to INDF2 or POSTDEC2 will write the same value to the FSR2H:FSR2L. Since the FSRs are physical registers mapped in the SFR space, they can be manipulated through all direct operations. Users should proceed cautiously when working on these registers, particularly if their code uses Indirect Addressing. Similarly, operations by Indirect Addressing are generally permitted on all other SFRs. Users should exercise the appropriate caution that they do not inadvertently change settings that might affect the operation of the device. 6.5 Program Memory and the Extended Instruction Set The operation of program memory is unaffected by the use of the extended instruction set. Enabling the extended instruction set adds five additional two-word commands to the existing PIC18 instruction set: ADDFSR, CALLW, MOVSF, MOVSS and SUBFSR. These instructions are executed as described in Section 6.2.4 "Two-Word Instructions". 2010 Microchip Technology Inc. PIC18F85J90 FAMILY 6.6 Data Memory and the Extended Instruction Set Enabling the PIC18 extended instruction set (XINST Configuration bit = 1) significantly changes certain aspects of data memory and its addressing. Specifically, the use of the Access Bank for many of the core PIC18 instructions is different; this is due to the introduction of a new addressing mode for the data memory space. This mode also alters the behavior of Indirect Addressing using FSR2 and its associated operands. What does not change is just as important. The size of the data memory space is unchanged, as well as its linear addressing. The SFR map remains the same. Core PIC18 instructions can still operate in both Direct and Indirect Addressing mode; inherent and literal instructions do not change at all. Indirect Addressing with FSR0 and FSR1 also remains unchanged. 6.6.1 INDEXED ADDRESSING WITH LITERAL OFFSET Enabling the PIC18 extended instruction set changes the behavior of Indirect Addressing using the FSR2 register pair and its associated file operands. Under the proper conditions, instructions that use the Access Bank - that is, most bit-oriented and byte-oriented instructions - can invoke a form of Indexed Addressing using an offset specified in the instruction. This special addressing mode is known as Indexed Addressing with Literal Offset, or Indexed Literal Offset mode. 6.6.2 INSTRUCTIONS AFFECTED BY INDEXED LITERAL OFFSET MODE Any of the core PIC18 instructions that can use Direct Addressing are potentially affected by the Indexed Literal Offset Addressing mode. This includes all byte-oriented and bit-oriented instructions, or almost one-half of the standard PIC18 instruction set. Instructions that only use Inherent or Literal Addressing modes are unaffected. Additionally, byte-oriented and bit-oriented instructions are not affected if they do not use the Access Bank (Access RAM bit is `1') or include a file address of 60h or above. Instructions meeting these criteria will continue to execute as before. A comparison of the different possible addressing modes when the extended instruction set is enabled is shown in Figure 6-10. Those who desire to use byte-oriented or bit-oriented instructions in the Indexed Literal Offset mode should note the changes to assembler syntax for this mode. This is described in more detail in Section 24.2.1 "Extended Instruction Syntax". When using the extended instruction set, this addressing mode requires the following: * The use of the Access Bank is forced (`a' = 0); and * The file address argument is less than or equal to 5Fh. Under these conditions, the file address of the instruction is not interpreted as the lower byte of an address (used with the BSR in Direct Addressing) or as an 8-bit address in the Access Bank. Instead, the value is interpreted as an offset value to an Address Pointer specified by FSR2. The offset and the contents of FSR2 are added to obtain the target address of the operation. 2010 Microchip Technology Inc. DS39770C-page 83 PIC18F85J90 FAMILY FIGURE 6-10: COMPARING ADDRESSING OPTIONS FOR BIT-ORIENTED AND BYTE-ORIENTED INSTRUCTIONS (EXTENDED INSTRUCTION SET ENABLED) EXAMPLE INSTRUCTION: ADDWF, f, d, a (Opcode: 0010 01da ffff ffff) When a = 0 and f 60h: The instruction executes in Direct Forced mode. `f' is interpreted as a location in the Access RAM between 060h and FFFh. This is the same as locations F60h to FFFh (Bank 15) of data memory. Locations below 060h are not available in this addressing mode. 000h 060h Bank 0 100h 00h Bank 1 through Bank 14 F00h 60h Valid range for `f' Access RAM FFh Bank 15 F40h SFRs FFFh When a = 0 and f5Fh: The instruction executes in Indexed Literal Offset mode. `f' is interpreted as an offset to the address value in FSR2. The two are added together to obtain the address of the target register for the instruction. The address can be anywhere in the data memory space. Note that in this mode, the correct syntax is now: ADDWF [k], d where `k' is the same as `f'. When a = 1 (all values of f): The instruction executes in Direct mode (also known as Direct Long mode). `f' is interpreted as a location in one of the 16 banks of the data memory space. The bank is designated by the Bank Select Register (BSR). The address can be in any implemented bank in the data memory space. Data Memory 000h Bank 0 060h 100h 001001da ffffffff Bank 1 through Bank 14 FSR2H FSR2L F00h Bank 15 F40h SFRs FFFh Data Memory BSR 00000000 000h Bank 0 060h 100h Bank 1 through Bank 14 001001da ffffffff F00h Bank 15 F40h SFRs FFFh DS39770C-page 84 Data Memory 2010 Microchip Technology Inc. PIC18F85J90 FAMILY 6.6.3 MAPPING THE ACCESS BANK IN INDEXED LITERAL OFFSET MODE The use of Indexed Literal Offset Addressing mode effectively changes how the lower part of Access RAM (00h to 5Fh) is mapped. Rather than containing just the contents of the bottom part of Bank 0, this mode maps the contents from Bank 0 and a user-defined "window" that can be located anywhere in the data memory space. The value of FSR2 establishes the lower boundary of the addresses mapped into the window, while the upper boundary is defined by FSR2 plus 95 (5Fh). Addresses in the Access RAM above 5Fh are mapped as previously described (see Section 6.3.2 "Access Bank"). An example of Access Bank remapping in this addressing mode is shown in Figure 6-11. FIGURE 6-11: Remapping of the Access Bank applies only to operations using the Indexed Literal Offset mode. Operations that use the BSR (Access RAM bit is `1') will continue to use Direct Addressing as before. Any Indirect or Indexed Addressing operation that explicitly uses any of the indirect file operands (including FSR2) will continue to operate as standard Indirect Addressing. Any instruction that uses the Access Bank, but includes a register address of greater than 05Fh, will use Direct Addressing and the normal Access Bank map. 6.6.4 BSR IN INDEXED LITERAL OFFSET MODE Although the Access Bank is remapped when the extended instruction set is enabled, the operation of the BSR remains unchanged. Direct Addressing, using the BSR to select the data memory bank, operates in the same manner as previously described. REMAPPING THE ACCESS BANK WITH INDEXED LITERAL OFFSET ADDRESSING Example Situation: ADDWF f, d, a FSR2H:FSR2L = 120h Locations in the region from the FSR2 Pointer (120h) to the pointer plus 05Fh (17Fh) are mapped to the bottom of the Access RAM (000h-05Fh). 000h 05Fh Bank 0 100h 120h 17Fh 200h Window Bank 1 00h Bank 1 "Window" 5Fh 60h Special Function Registers at F60h through FFFh are mapped to 60h through FFh, as usual. Bank 0 addresses below 5Fh are not available in this mode. They can still be addressed by using the BSR. Not Accessible Bank 2 through Bank 14 SFRs FFh Access Bank F00h Bank 15 F60h FFFh SFRs Data Memory 2010 Microchip Technology Inc. DS39770C-page 85 PIC18F85J90 FAMILY NOTES: DS39770C-page 86 2010 Microchip Technology Inc. PIC18F85J90 FAMILY 7.0 FLASH PROGRAM MEMORY 7.1 Table Reads and Table Writes The Flash program memory is readable, writable and erasable during normal operation over the entire VDD range. In order to read and write program memory, there are two operations that allow the processor to move bytes between the program memory space and the data RAM: A read from program memory is executed on one byte at a time. A write to program memory is executed on blocks of 64 bytes at a time. Program memory is erased in blocks of 1024 bytes at a time. A bulk erase operation may not be issued from user code. * Table Read (TBLRD) * Table Write (TBLWT) Writing or erasing program memory will cease instruction fetches until the operation is complete. The program memory cannot be accessed during the write or erase, therefore, code cannot execute. An internal programming timer terminates program memory writes and erases. A value written to program memory does not need to be a valid instruction. Executing a program memory location that forms an invalid instruction results in a NOP. The program memory space is 16 bits wide, while the data RAM space is 8 bits wide. Table reads and table writes move data between these two memory spaces through an 8-bit register (TABLAT). Table read operations retrieve data from program memory and place it into the data RAM space. Figure 7-1 shows the operation of a table read with program memory and data RAM. Table write operations store data from the data memory space into holding registers in program memory. The procedure to write the contents of the holding registers into program memory is detailed in Section 7.5 "Writing to Flash Program Memory". Figure 7-2 shows the operation of a table write with program memory and data RAM. Table operations work with byte entities. A table block containing data, rather than program instructions, is not required to be word-aligned. Therefore, a table block can start and end at any byte address. If a table write is being used to write executable code into program memory, program instructions will need to be word-aligned. FIGURE 7-1: TABLE READ OPERATION Instruction: TBLRD* Program Memory Table Pointer(1) TBLPTRU TBLPTRH TBLPTRL Table Latch (8-bit) TABLAT Program Memory (TBLPTR) Note 1: The Table Pointer register points to a byte in program memory. 2010 Microchip Technology Inc. DS39770C-page 87 PIC18F85J90 FAMILY FIGURE 7-2: TABLE WRITE OPERATION Instruction: TBLWT* Program Memory Holding Registers Table Pointer(1) TBLPTRU TBLPTRH Table Latch (8-bit) TBLPTRL TABLAT Program Memory (TBLPTR) Note 1: 7.2 The Table Pointer actually points to one of 64 holding registers, the address of which is determined by TBLPTRL<5:0>. The process for physically writing data to the program memory array is discussed in Section 7.5 "Writing to Flash Program Memory". Control Registers Several control registers are used in conjunction with the TBLRD and TBLWT instructions. These include the: * * * * EECON1 register EECON2 register TABLAT register TBLPTR registers 7.2.1 EECON1 AND EECON2 REGISTERS The EECON1 register (Register 7-1) is the control register for memory accesses. The EECON2 register is not a physical register; it is used exclusively in the memory write and erase sequences. Reading EECON2 will read all `0's. The WREN bit, when set, will allow a write operation. On power-up, the WREN bit is clear. The WRERR bit is set in hardware when the WR bit is set and cleared when the internal programming timer expires and the write operation is complete. Note: During normal operation, the WRERR is read as `1'. This can indicate that a write operation was prematurely terminated by a Reset, or a write operation was attempted improperly. The WR control bit initiates write operations. The bit cannot be cleared, only set, in software. It is cleared in hardware at the completion of the write operation. The FREE bit, when set, will allow a program memory erase operation. When FREE is set, the erase operation is initiated on the next WR command. When FREE is clear, only writes are enabled. DS39770C-page 88 2010 Microchip Technology Inc. PIC18F85J90 FAMILY REGISTER 7-1: EECON1: EEPROM CONTROL REGISTER 1 U-0 U-0 U-0 R/W-0 R/W-x R/W-0 R/S-0 U-0 -- -- -- FREE WRERR WREN WR -- bit 7 bit 0 Legend: U = Unimplemented bit, read as `0' R = Readable bit W = Writable bit S = Settable bit (cannot be cleared in software) -n = Value at POR `1' = Bit is set `0' = Bit is cleared x = Bit is unknown bit 7-5 Unimplemented: Read as `0' bit 4 FREE: Flash Erase Enable bit 1 = Erase the program memory block addressed by TBLPTR on the next WR command (cleared by completion of erase operation) 0 = Perform write only bit 3 WRERR: Flash Program Error Flag bit 1 = A write operation is prematurely terminated (any Reset during self-timed programming in normal operation, or an improper write attempt) 0 = The write operation completed bit 2 WREN: Flash Program Write Enable bit 1 = Allows write cycles to Flash program memory 0 = Inhibits write cycles to Flash program memory bit 1 WR: Write Control bit 1 = Initiates a program memory erase cycle or write cycle (The operation is self-timed and the bit is cleared by hardware once the write is complete. The WR bit can only be set (not cleared) in software.) 0 = Write cycle is complete bit 0 Unimplemented: Read as `0' 2010 Microchip Technology Inc. DS39770C-page 89 PIC18F85J90 FAMILY 7.2.2 TABLE LATCH REGISTER (TABLAT) 7.2.4 The Table Latch (TABLAT) is an 8-bit register mapped into the SFR space. The Table Latch register is used to hold 8-bit data during data transfers between program memory and data RAM. 7.2.3 TBLPTR is used in reads, writes and erases of the Flash program memory. When a TBLRD is executed, all 22 bits of the TBLPTR determine which byte is read from program memory into TABLAT. TABLE POINTER REGISTER (TBLPTR) When a TBLWT is executed, the seven LSbs of the Table Pointer register (TBLPTR<6:0>) determine which of the 64 program memory holding registers is written to. When the timed write to program memory begins (via the WR bit), the 12 MSbs of the TBLPTR (TBLPTR<21:10>) determine which program memory block of 1024 bytes is written to. For more detail, see Section 7.5 "Writing to Flash Program Memory". The Table Pointer (TBLPTR) register addresses a byte within the program memory. The TBLPTR is comprised of three SFR registers: Table Pointer Upper Byte, Table Pointer High Byte and Table Pointer Low Byte (TBLPTRU:TBLPTRH:TBLPTRL). These three registers join to form a 22-bit wide pointer. The low-order 21 bits allow the device to address up to 2 Mbytes of program memory space. The 22nd bit allows access to the device ID, the user ID and the Configuration bits. When an erase of program memory is executed, the 12 MSbs of the Table Pointer register point to the 1024-byte block that will be erased. The Least Significant bits are ignored. The Table Pointer register, TBLPTR, is used by the TBLRD and TBLWT instructions. These instructions can update the TBLPTR in one of four ways based on the table operation. These operations are shown in Table 7-1. These operations on the TBLPTR only affect the low-order 21 bits. TABLE 7-1: TABLE POINTER BOUNDARIES Figure 7-3 describes the relevant boundaries of the TBLPTR based on Flash program memory operations. TABLE POINTER OPERATIONS WITH TBLRD AND TBLWT INSTRUCTIONS Example Operation on Table Pointer TBLRD* TBLWT* TBLPTR is not modified TBLRD*+ TBLWT*+ TBLPTR is incremented after the read/write TBLRD*TBLWT*- TBLPTR is decremented after the read/write TBLRD+* TBLWT+* TBLPTR is incremented before the read/write FIGURE 7-3: 21 TABLE POINTER BOUNDARIES BASED ON OPERATION TBLPTRU 16 15 TBLPTRH 8 7 TBLPTRL 0 ERASE: TBLPTR<21:10> TABLE WRITE: TBLPTR<21:6> TABLE READ: TBLPTR<21:0> DS39770C-page 90 2010 Microchip Technology Inc. PIC18F85J90 FAMILY 7.3 Reading the Flash Program Memory The internal program memory is typically organized by words. The Least Significant bit of the address selects between the high and low bytes of the word. Figure 7-4 shows the interface between the internal program memory and the TABLAT. The TBLRD instruction is used to retrieve data from program memory and places it into data RAM. Table reads from program memory are performed one byte at a time. The TBLPTR points to a byte address in program space. Executing TBLRD places the byte pointed to into TABLAT. In addition, the TBLPTR can be modified automatically for the next table read operation. FIGURE 7-4: READS FROM FLASH PROGRAM MEMORY Program Memory (Even Byte Address) (Odd Byte Address) TBLPTR = xxxxx1 Instruction Register (IR) EXAMPLE 7-1: FETCH TBLRD TBLPTR = xxxxx0 TABLAT Read Register READING A FLASH PROGRAM MEMORY WORD MOVLW MOVWF MOVLW MOVWF MOVLW MOVWF CODE_ADDR_UPPER TBLPTRU CODE_ADDR_HIGH TBLPTRH CODE_ADDR_LOW TBLPTRL ; Load TBLPTR with the base ; address of the word READ_WORD TBLRD*+ MOVF MOVWF TBLRD*+ MOVF MOVWF TABLAT, W WORD_EVEN TABLAT, W WORD_ODD 2010 Microchip Technology Inc. ; read into TABLAT and increment ; get data ; read into TABLAT and increment ; get data DS39770C-page 91 PIC18F85J90 FAMILY 7.4 Erasing Flash Program Memory The minimum erase block is 512 words or 1024 bytes. Only through the use of an external programmer, or through ICSP control, can larger blocks of program memory be Bulk Erased. Word erase in the Flash array is not supported. When initiating an erase sequence from the microcontroller itself, a block of 1024 bytes of program memory is erased. The Most Significant 12 bits of the TBLPTR<21:10> point to the block being erased; TBLPTR<9:0> are ignored. The EECON1 register commands the erase operation. The WREN bit must be set to enable write operations. The FREE bit is set to select an erase operation. For protection, the write initiate sequence for EECON2 must be used. 7.4.1 FLASH PROGRAM MEMORY ERASE SEQUENCE The sequence of events for erasing a block of internal program memory location is: 1. 2. 3. 4. 5. 6. 7. 8. Load the Table Pointer register with the address of the block being erased. Set the WREN and FREE bits (EECON1<2,4>) to enable the erase operation. Disable interrupts. Write 55h to EECON2. Write 0AAh to EECON2. Set the WR bit; this will begin the erase cycle. The CPU will stall for the duration of the erase for TIE (see parameter D133B). Re-enable interrupts. A long write is necessary for erasing the internal Flash. Instruction execution is halted while in a long write cycle. The long write will be terminated by the internal programming timer. EXAMPLE 7-2: ERASING A FLASH PROGRAM MEMORY BLOCK MOVLW MOVWF MOVLW MOVWF MOVLW MOVWF CODE_ADDR_UPPER TBLPTRU CODE_ADDR_HIGH TBLPTRH CODE_ADDR_LOW TBLPTRL ; load TBLPTR with the base ; address of the memory block BSF BSF BCF MOVLW MOVWF MOVLW MOVWF BSF BSF EECON1, EECON1, INTCON, 55h EECON2 0AAh EECON2 EECON1, INTCON, ; enable write to memory ; enable Erase operation ; disable interrupts ERASE_BLOCK Required Sequence DS39770C-page 92 WREN FREE GIE ; write 55h WR GIE ; write 0AAh ; start erase (CPU stall) ; re-enable interrupts 2010 Microchip Technology Inc. PIC18F85J90 FAMILY 7.5 Writing to Flash Program Memory The on-chip timer controls the write time. The write/erase voltages are generated by an on-chip charge pump, rated to operate over the voltage range of the device. The minimum programming block is 32 words or 64 bytes. Word or byte programming is not supported. Table writes are used internally to load the holding registers needed to program the Flash memory. There are 64 holding registers used by the table writes for programming. Note 1: Unlike previous PIC(R) devices, members of the PIC18F85J90 family do not reset the holding registers after a write occurs. The holding registers must be cleared or overwritten before a programming sequence. Since the Table Latch (TABLAT) is only a single byte, the TBLWT instruction may need to be executed 64 times for each programming operation. All of the table write operations will essentially be short writes because only the holding registers are written. At the end of updating the 64 holding registers, the EECON1 register must be written to in order to start the programming operation with a long write. 2: To maintain the endurance of the program memory cells, each Flash byte should not be programmed more than one time between erase operations. Before attempting to modify the contents of the target cell a second time, a block erase of the target block, or a bulk erase of the entire memory, must be performed. The long write is necessary for programming the internal Flash. Instruction execution is halted while in a long write cycle. The long write will be terminated by the internal programming timer. FIGURE 7-5: TABLE WRITES TO FLASH PROGRAM MEMORY TABLAT Write Register 8 8 TBLPTR = xxxxx0 8 TBLPTR = xxxxx1 Holding Register TBLPTR = xxxx3F TBLPTR = xxxxx2 Holding Register 8 Holding Register Holding Register Program Memory 7.5.1 FLASH PROGRAM MEMORY WRITE SEQUENCE The sequence of events for programming an internal program memory location should be: 1. 2. 3. 4. 5. 6. 7. Read 1024 bytes into RAM. Update data values in RAM as necessary. Load the Table Pointer register with the address being erased. Execute the block erase procedure. Load the Table Pointer register with the address of the first byte being written, minus 1. Write the 64 bytes into the holding registers with auto-increment. Set the WREN bit (EECON1<2>) to enable byte writes. 2010 Microchip Technology Inc. 8. 9. 10. 11. 12. Disable interrupts. Write 55h to EECON2. Write 0AAh to EECON2. Set the WR bit; this will begin the write cycle. The CPU will stall for the duration of the write for TIW (see parameter D133A). 13. Re-enable interrupts. 14. Repeat steps 6 through 13 until all 1024 bytes are written to program memory. 15. Verify the memory (table read). An example of the required code is shown in Example 7-3 on the following page. Note: Before setting the WR bit, the Table Pointer address needs to be within the intended address range of the 64 bytes in the holding register. DS39770C-page 93 PIC18F85J90 FAMILY EXAMPLE 7-3: WRITING TO FLASH PROGRAM MEMORY MOVLW MOVWF MOVLW MOVWF MOVLW MOVWF CODE_ADDR_UPPER TBLPTRU CODE_ADDR_HIGH TBLPTRH CODE_ADDR_LOW TBLPTRL ; Load TBLPTR with the base address ; of the memory block, minus 1 BSF BSF BCF MOVLW MOVWF MOVLW MOVWF BSF BSF MOVLW MOVWF EECON1, WREN EECON1, FREE INTCON, GIE 55h EECON2 0AAh EECON2 EECON1, WR INTCON, GIE D'16' WRITE_COUNTER ; enable write to memory ; enable Erase operation ; disable interrupts MOVLW MOVWF MOVLW MOVWF MOVLW MOVWF D'64' COUNTER BUFFER_ADDR_HIGH FSR0H BUFFER_ADDR_LOW FSR0L ERASE_BLOCK ; write 55h ; write 0AAh ; start erase (CPU stall) ; re-enable interrupts ; Need to write 16 blocks of 64 to write ; one erase block of 1024 RESTART_BUFFER ; point to buffer FILL_BUFFER ... ; read the new data from I2C, SPI, ; PSP, USART, etc. WRITE_BUFFER MOVLW MOVWF WRITE_BYTE_TO_HREGS MOVFF MOVWF TBLWT+* D'64 COUNTER ; number of bytes in holding register POSTINC0, WREG TABLAT ; ; ; ; ; DECFSZ COUNTER BRA WRITE_BYTE_TO_HREGS get low byte of buffer data present data to table latch write data, perform a short write to internal TBLWT holding register. loop until buffers are full PROGRAM_MEMORY Required Sequence BSF BCF MOVLW MOVWF MOVLW MOVWF BSF BSF BCF EECON1, INTCON, 55h EECON2 0AAh EECON2 EECON1, INTCON, EECON1, WREN GIE ; write 55h WR GIE WREN DECFSZ WRITE_COUNTER BRA RESTART_BUFFER DS39770C-page 94 ; enable write to memory ; disable interrupts ; ; ; ; write 0AAh start program (CPU stall) re-enable interrupts disable write to memory ; done with one write cycle ; if not done replacing the erase block 2010 Microchip Technology Inc. PIC18F85J90 FAMILY 7.5.2 7.6 WRITE VERIFY Depending on the application, good programming practice may dictate that the value written to the memory should be verified against the original value. This should be used in applications where excessive writes can stress bits near the specification limit. 7.5.3 Flash Program Operation During Code Protection See Section 23.6 "Program Verification and Code Protection" for details on code protection of Flash program memory. UNEXPECTED TERMINATION OF WRITE OPERATION If a write is terminated by an unplanned event, such as loss of power or an unexpected Reset, the memory location just programmed should be verified and reprogrammed if needed. If the write operation is interrupted by a MCLR Reset or a WDT Time-out Reset during normal operation, the user can check the WRERR bit and rewrite the location(s) as needed. TABLE 7-2: REGISTERS ASSOCIATED WITH PROGRAM FLASH MEMORY Name Bit 7 Bit 6 Bit 5 TBLPTRU -- -- bit 21 Bit 4 Bit 3 Bit 2 Bit 1 Bit 0 Program Memory Table Pointer Upper Byte (TBLPTR<20:16>) Reset Values on page 57 TBPLTRH Program Memory Table Pointer High Byte (TBLPTR<15:8>) 57 TBLPTRL Program Memory Table Pointer Low Byte (TBLPTR<7:0>) 57 TABLAT 57 Program Memory Table Latch INTCON GIE/GIEH PEIE/GIEL TMR0IE EECON2 EEPROM Control Register 2 (not a physical register) EECON1 -- -- -- INT0IE FREE RBIE WRERR TMR0IF INT0IF RBIF 57 59 WREN WR -- 59 Legend: -- = unimplemented, read as `0'. Shaded cells are not used during program memory access. 2010 Microchip Technology Inc. DS39770C-page 95 PIC18F85J90 FAMILY NOTES: DS39770C-page 96 2010 Microchip Technology Inc. PIC18F85J90 FAMILY 8.0 8 x 8 HARDWARE MULTIPLIER 8.1 Introduction EXAMPLE 8-1: MOVF MULWF All PIC18 devices include an 8 x 8 hardware multiplier as part of the ALU. The multiplier performs an unsigned operation and yields a 16-bit result that is stored in the Product register pair, PRODH:PRODL. The multiplier's operation does not affect any flags in the STATUS register. ARG1, W ARG2 EXAMPLE 8-2: Making multiplication a hardware operation allows it to be completed in a single instruction cycle. This has the advantages of higher computational throughput and reduced code size for multiplication algorithms and allows the PIC18 devices to be used in many applications previously reserved for digital signal processors. A comparison of various hardware and software multiply operations, along with the savings in memory and execution time, is shown in Table 8-1. 8.2 8 x 8 UNSIGNED MULTIPLY ROUTINE ; ; ARG1 * ARG2 -> ; PRODH:PRODL 8 x 8 SIGNED MULTIPLY ROUTINE MOVF MULWF ARG1, W ARG2 BTFSC SUBWF ARG2, SB PRODH, F MOVF BTFSC SUBWF ARG2, W ARG1, SB PRODH, F ; ; ; ; ; ARG1 * ARG2 -> PRODH:PRODL Test Sign Bit PRODH = PRODH - ARG1 ; Test Sign Bit ; PRODH = PRODH ; - ARG2 Operation Example 8-1 shows the instruction sequence for an 8 x 8 unsigned multiplication. Only one instruction is required when one of the arguments is already loaded in the WREG register. Example 8-2 shows the sequence to do an 8 x 8 signed multiplication. To account for the sign bits of the arguments, each argument's Most Significant bit (MSb) is tested and the appropriate subtractions are done. TABLE 8-1: PERFORMANCE COMPARISON FOR VARIOUS MULTIPLY OPERATIONS Routine 8 x 8 unsigned 8 x 8 signed 16 x 16 unsigned 16 x 16 signed Multiply Method Program Memory (Words) Cycles (Max) @ 40 MHz @ 10 MHz @ 4 MHz Without hardware multiply 13 69 6.9 s 27.6 s 69 s Time Hardware multiply 1 1 100 ns 400 ns 1 s Without hardware multiply 33 91 9.1 s 36.4 s 91 s Hardware multiply 6 6 600 ns 2.4 s 6 s Without hardware multiply 21 242 24.2 s 96.8 s 242 s Hardware multiply 28 28 2.8 s 11.2 s 28 s Without hardware multiply 52 254 25.4 s 102.6 s 254 s Hardware multiply 35 40 4.0 s 16.0 s 40 s 2010 Microchip Technology Inc. DS39770C-page 97 PIC18F85J90 FAMILY Example 8-3 shows the sequence to do a 16 x 16 unsigned multiplication. Equation 8-1 shows the algorithm that is used. The 32-bit result is stored in four registers (RES3:RES0). EQUATION 8-1: RES3:RES0 = = EXAMPLE 8-3: 16 x 16 UNSIGNED MULTIPLICATION ALGORITHM ARG1H:ARG1L ARG2H:ARG2L (ARG1H ARG2H 216) + (ARG1H ARG2L 28) + (ARG1L ARG2H 28) + (ARG1L ARG2L) EQUATION 8-2: RES3:RES0 = ARG1H:ARG1L ARG2H:ARG2L = (ARG1H ARG2H 216) + (ARG1H ARG2L 28) + (ARG1L ARG2H 28) + (ARG1L ARG2L) + (-1 ARG2H<7> ARG1H:ARG1L 216) + (-1 ARG1H<7> ARG2H:ARG2L 216) EXAMPLE 8-4: 16 x 16 UNSIGNED MULTIPLY ROUTINE MOVF MULWF ARG1L, W ARG2L MOVFF MOVFF PRODH, RES1 PRODL, RES0 MOVF MULWF ARG1H, W ARG2H MOVFF MOVFF PRODH, RES3 PRODL, RES2 MOVF MULWF ARG1L, W ARG2H MOVF ADDWF MOVF ADDWFC CLRF ADDWFC PRODL, W RES1, F PRODH, W RES2, F WREG RES3, F MOVF MULWF ARG1H, W ARG2L MOVF ADDWF MOVF ADDWFC CLRF ADDWFC PRODL, W RES1, F PRODH, W RES2, F WREG RES3, F ; ARG1L * ARG2L-> ; PRODH:PRODL ; ; ARG1L * ARG2H-> PRODH:PRODL Add cross products ARG1H * ARG2L-> PRODH:PRODL Add cross products Example 8-4 shows the sequence to do a 16 x 16 signed multiply. Equation 8-2 shows the algorithm used. The 32-bit result is stored in four registers (RES3:RES0). To account for the sign bits of the arguments, the MSb for each argument pair is tested and the appropriate subtractions are done. DS39770C-page 98 ARG1L, W ARG2L MOVFF MOVFF PRODH, RES1 PRODL, RES0 MOVF MULWF ARG1H, W ARG2H MOVFF MOVFF PRODH, RES3 PRODL, RES2 MOVF MULWF ARG1L, W ARG2H MOVF ADDWF MOVF ADDWFC CLRF ADDWFC PRODL, W RES1, F PRODH, W RES2, F WREG RES3, F MOVF MULWF ARG1H, W ARG2L MOVF ADDWF MOVF ADDWFC CLRF ADDWFC PRODL, W RES1, F PRODH, W RES2, F WREG RES3, F BTFSS BRA MOVF SUBWF MOVF SUBWFB ARG2H, 7 SIGN_ARG1 ARG1L, W RES2 ARG1H, W RES3 ; ARG2H:ARG2L neg? ; no, check ARG1 ; ; ; ARG1H, 7 CONT_CODE ARG2L, W RES2 ARG2H, W RES3 ; ARG1H:ARG1L neg? ; no, done ; ; ; ; ARG1L * ARG2L -> ; PRODH:PRODL ; ; ; ARG1H * ARG2H -> ; PRODH:PRODL ; ; ; ; ; ; ; ; ; ; ARG1L * ARG2H -> PRODH:PRODL Add cross products ; ; ; ; ; ; ; ; ; ; ; MOVF MULWF ; ; ; ; ; ; ; ; ; ; 16 x 16 SIGNED MULTIPLY ROUTINE ; ; ; ARG1H * ARG2H-> ; PRODH:PRODL ; ; 16 x 16 SIGNED MULTIPLICATION ALGORITHM ; ; ; ; ; ; ; ; ; ARG1H * ARG2L -> PRODH:PRODL Add cross products ; ; SIGN_ARG1 BTFSS BRA MOVF SUBWF MOVF SUBWFB ; CONT_CODE : 2010 Microchip Technology Inc. PIC18F85J90 FAMILY 9.0 INTERRUPTS Members of the PIC18F85J90 family of devices have multiple interrupt sources and an interrupt priority feature that allows most interrupt sources to be assigned a high-priority level or a low-priority level. The high-priority interrupt vector is at 0008h and the low-priority interrupt vector is at 0018h. High-priority interrupt events will interrupt any low-priority interrupts that may be in progress. There are thirteen registers which are used to control interrupt operation. These registers are: * * * * * * * RCON INTCON INTCON2 INTCON3 PIR1, PIR2, PIR3 PIE1, PIE2, PIE3 IPR1, IPR2, IPR3 It is recommended that the Microchip header files supplied with MPLAB(R) IDE be used for the symbolic bit names in these registers. This allows the assembler/compiler to automatically take care of the placement of these bits within the specified register. In general, interrupt sources have three bits to control their operation. They are: * Flag bit to indicate that an interrupt event occurred * Enable bit that allows program execution to branch to the interrupt vector address when the flag bit is set * Priority bit to select high priority or low priority The interrupt priority feature is enabled by setting the IPEN bit (RCON<7>). When interrupt priority is enabled, there are two bits which enable interrupts globally. Setting the GIEH bit (INTCON<7>) enables all interrupts that have the priority bit set (high priority). Setting the GIEL bit (INTCON<6>) enables all interrupts that have the priority bit cleared (low priority). When the interrupt flag, enable bit and appropriate global interrupt enable bit are set, the interrupt will vector immediately to address 0008h or 0018h, depending on the priority bit setting. Individual interrupts can be disabled through their corresponding enable bits. 2010 Microchip Technology Inc. When the IPEN bit is cleared (default state), the interrupt priority feature is disabled and interrupts are compatible with PIC(R) mid-range devices. In Compatibility mode, the interrupt priority bits for each source have no effect. INTCON<6> is the PEIE bit which enables/disables all peripheral interrupt sources. INTCON<7> is the GIE bit which enables/disables all interrupt sources. All interrupts branch to address 0008h in Compatibility mode. When an interrupt is responded to, the global interrupt enable bit is cleared to disable further interrupts. If the IPEN bit is cleared, this is the GIE bit. If interrupt priority levels are used, this will be either the GIEH or GIEL bit. High-priority interrupt sources can interrupt a low-priority interrupt. Low-priority interrupts are not processed while high-priority interrupts are in progress. The return address is pushed onto the stack and the PC is loaded with the interrupt vector address (0008h or 0018h). Once in the Interrupt Service Routine, the source(s) of the interrupt can be determined by polling the interrupt flag bits. The interrupt flag bits must be cleared in software before re-enabling interrupts to avoid recursive interrupts. The "return from interrupt" instruction, RETFIE, exits the interrupt routine and sets the GIE bit (GIEH or GIEL if priority levels are used) which re-enables interrupts. For external interrupt events, such as the INT pins or the PORTB input change interrupt, the interrupt latency will be three to four instruction cycles. The exact latency is the same for one or two-cycle instructions. Individual interrupt flag bits are set regardless of the status of their corresponding enable bit or the GIE bit. Note: Do not use the MOVFF instruction to modify any of the Interrupt Control registers while any interrupt is enabled. Doing so may cause erratic microcontroller behavior. DS39770C-page 99 PIC18F85J90 FAMILY FIGURE 9-1: PIC18F85J90 FAMILY INTERRUPT LOGIC PIR1<6:3,1:0> PIE1<6:3,1:0> IPR1<6:3,1:0> PIR2<7:6,3:1> PIE2<7:6 3:1> IPR2<7:6,3:1> Wake-up if in Idle or Sleep modes TMR0IF TMR0IE TMR0IP RBIF RBIE RBIP INT0IF INT0IE INT1IF INT1IE INT1IP INT2IF INT2IE INT2IP INT3IF INT3IE INT3IP Interrupt to CPU Vector to Location 0008h GIE/GIEH IPEN PIR3<6:4,2:1> PIE3<6:4,2:1> IPR3<6:4,2:1> IPEN PEIE/GIEL IPEN High-Priority Interrupt Generation Low-Priority Interrupt Generation PIR1<6:3,1:0> PIE1<6:3,1:0> IPR1<6:3,1:0> PIR2<7:6,3:1> PIE2<7:6,3:1> IPR2<7:6,3:1> PIR3<6:4,2:1> PIE3<6:4,2:1> IPR3<6:4,2:1> TMR0IF TMR0IE TMR0IP RBIF RBIE RBIP INT1IF INT1IE INT1IP INT2IF INT2IE INT2IP INT3IF INT3IE INT3IP DS39770C-page 100 Interrupt to CPU Vector to Location 0018h IPEN GIE/GIEH PEIE/GIEL 2010 Microchip Technology Inc. PIC18F85J90 FAMILY 9.1 INTCON Registers Note: The INTCON registers are readable and writable registers which contain various enable, priority and flag bits. REGISTER 9-1: Interrupt flag bits are set when an interrupt condition occurs regardless of the state of its corresponding enable bit or the global interrupt enable bit. User software should ensure the appropriate interrupt flag bits are clear prior to enabling an interrupt. This feature allows for software polling. INTCON: INTERRUPT CONTROL REGISTER R/W-0 R/W-0 R/W-0 R/W-0 R/W-0 R/W-0 R/W-0 R/W-x GIE/GIEH PEIE/GIEL TMR0IE INT0IE RBIE TMR0IF INT0IF RBIF(1) bit 7 bit 0 Legend: R = Readable bit W = Writable bit U = Unimplemented bit, read as `0' -n = Value at POR `1' = Bit is set `0' = Bit is cleared x = Bit is unknown bit 7 GIE/GIEH: Global Interrupt Enable bit When IPEN = 0: 1 = Enables all unmasked interrupts 0 = Disables all interrupts When IPEN = 1: 1 = Enables all high-priority interrupts 0 = Disables all interrupts bit 6 PEIE/GIEL: Peripheral Interrupt Enable bit When IPEN = 0: 1 = Enables all unmasked peripheral interrupts 0 = Disables all peripheral interrupts When IPEN = 1: 1 = Enables all low-priority peripheral interrupts 0 = Disables all low-priority peripheral interrupts bit 5 TMR0IE: TMR0 Overflow Interrupt Enable bit 1 = Enables the TMR0 overflow interrupt 0 = Disables the TMR0 overflow interrupt bit 4 INT0IE: INT0 External Interrupt Enable bit 1 = Enables the INT0 external interrupt 0 = Disables the INT0 external interrupt bit 3 RBIE: RB Port Change Interrupt Enable bit 1 = Enables the RB port change interrupt 0 = Disables the RB port change interrupt bit 2 TMR0IF: TMR0 Overflow Interrupt Flag bit 1 = TMR0 register has overflowed (must be cleared in software) 0 = TMR0 register did not overflow bit 1 INT0IF: INT0 External Interrupt Flag bit 1 = The INT0 external interrupt occurred (must be cleared in software) 0 = The INT0 external interrupt did not occur bit 0 RBIF: RB Port Change Interrupt Flag bit(1) 1 = At least one of the RB<7:4> pins changed state (must be cleared in software) 0 = None of the RB<7:4> pins have changed state Note 1: A mismatch condition will continue to set this bit. Reading PORTB, and then waiting one additional instruction cycle, will end the mismatch condition and allow the bit to be cleared. 2010 Microchip Technology Inc. DS39770C-page 101 PIC18F85J90 FAMILY REGISTER 9-2: INTCON2: INTERRUPT CONTROL REGISTER 2 R/W-1 R/W-1 R/W-1 R/W-1 R/W-1 R/W-1 R/W-1 R/W-1 RBPU INTEDG0 INTEDG1 INTEDG2 INTEDG3 TMR0IP INT3IP RBIP bit 7 bit 0 Legend: R = Readable bit W = Writable bit U = Unimplemented bit, read as `0' -n = Value at POR `1' = Bit is set `0' = Bit is cleared bit 7 RBPU: PORTB Pull-up Enable bit 1 = All PORTB pull-ups are disabled 0 = PORTB pull-ups are enabled by individual port latch values bit 6 INTEDG0: External Interrupt 0 Edge Select bit 1 = Interrupt on rising edge 0 = Interrupt on falling edge bit 5 INTEDG1: External Interrupt 1 Edge Select bit 1 = Interrupt on rising edge 0 = Interrupt on falling edge bit 4 INTEDG2: External Interrupt 2 Edge Select bit 1 = Interrupt on rising edge 0 = Interrupt on falling edge bit 3 INTEDG3: External Interrupt 3 Edge Select bit 1 = Interrupt on rising edge 0 = Interrupt on falling edge bit 2 TMR0IP: TMR0 Overflow Interrupt Priority bit 1 = High priority 0 = Low priority bit 1 INT3IP: INT3 External Interrupt Priority bit 1 = High priority 0 = Low priority bit 0 RBIP: RB Port Change Interrupt Priority bit 1 = High priority 0 = Low priority Note: x = Bit is unknown Interrupt flag bits are set when an interrupt condition occurs regardless of the state of its corresponding enable bit or the global interrupt enable bit. User software should ensure the appropriate interrupt flag bits are clear prior to enabling an interrupt. This feature allows for software polling. DS39770C-page 102 2010 Microchip Technology Inc. PIC18F85J90 FAMILY REGISTER 9-3: INTCON3: INTERRUPT CONTROL REGISTER 3 R/W-1 R/W-1 R/W-0 R/W-0 R/W-0 R/W-0 R/W-0 R/W-0 INT2IP INT1IP INT3IE INT2IE INT1IE INT3IF INT2IF INT1IF bit 7 bit 0 Legend: R = Readable bit W = Writable bit U = Unimplemented bit, read as `0' -n = Value at POR `1' = Bit is set `0' = Bit is cleared bit 7 INT2IP: INT2 External Interrupt Priority bit 1 = High priority 0 = Low priority bit 6 INT1IP: INT1 External Interrupt Priority bit 1 = High priority 0 = Low priority bit 5 INT3IE: INT3 External Interrupt Enable bit 1 = Enables the INT3 external interrupt 0 = Disables the INT3 external interrupt bit 4 INT2IE: INT2 External Interrupt Enable bit 1 = Enables the INT2 external interrupt 0 = Disables the INT2 external interrupt bit 3 INT1IE: INT1 External Interrupt Enable bit 1 = Enables the INT1 external interrupt 0 = Disables the INT1 external interrupt bit 2 INT3IF: INT3 External Interrupt Flag bit 1 = The INT3 external interrupt occurred (must be cleared in software) 0 = The INT3 external interrupt did not occur bit 1 INT2IF: INT2 External Interrupt Flag bit 1 = The INT2 external interrupt occurred (must be cleared in software) 0 = The INT2 external interrupt did not occur bit 0 INT1IF: INT1 External Interrupt Flag bit 1 = The INT1 external interrupt occurred (must be cleared in software) 0 = The INT1 external interrupt did not occur Note: x = Bit is unknown Interrupt flag bits are set when an interrupt condition occurs regardless of the state of its corresponding enable bit or the global interrupt enable bit. User software should ensure the appropriate interrupt flag bits are clear prior to enabling an interrupt. This feature allows for software polling. 2010 Microchip Technology Inc. DS39770C-page 103 PIC18F85J90 FAMILY 9.2 PIR Registers The PIR registers contain the individual flag bits for the peripheral interrupts. Due to the number of peripheral interrupt sources, there are three Peripheral Interrupt Request (Flag) registers (PIR1, PIR2, PIR3). REGISTER 9-4: Note 1: Interrupt flag bits are set when an interrupt condition occurs regardless of the state of its corresponding enable bit or the Global Interrupt Enable bit, GIE (INTCON<7>). 2: User software should ensure the appropriate interrupt flag bits are cleared prior to enabling an interrupt and after servicing that interrupt. PIR1: PERIPHERAL INTERRUPT REQUEST (FLAG) REGISTER 1 U-0 R/W-0 R-0 R-0 R/W-0 U-0 R/W-0 R/W-0 -- ADIF RC1IF TX1IF SSPIF -- TMR2IF TMR1IF bit 7 bit 0 Legend: R = Readable bit W = Writable bit U = Unimplemented bit, read as `0' -n = Value at POR `1' = Bit is set `0' = Bit is cleared x = Bit is unknown bit 7 Unimplemented: Read as `0' bit 6 ADIF: A/D Converter Interrupt Flag bit 1 = An A/D conversion completed (must be cleared in software) 0 = The A/D conversion is not complete bit 5 RC1IF: EUSART Receive Interrupt Flag bit 1 = The EUSART receive buffer, RCREG1, is full (cleared when RCREG1 is read) 0 = The EUSART receive buffer is empty bit 4 TX1IF: EUSART Transmit Interrupt Flag bit 1 = The EUSART transmit buffer, TXREG1, is empty (cleared when TXREG1 is written) 0 = The EUSART transmit buffer is full bit 3 SSPIF: Master Synchronous Serial Port Interrupt Flag bit 1 = The transmission/reception is complete (must be cleared in software) 0 = Waiting to transmit/receive bit 2 Unimplemented: Read as `0' bit 1 TMR2IF: TMR2 to PR2 Match Interrupt Flag bit 1 = TMR2 to PR2 match occurred (must be cleared in software) 0 = No TMR2 to PR2 match occurred bit 0 TMR1IF: TMR1 Overflow Interrupt Flag bit 1 = TMR1 register overflowed (must be cleared in software) 0 = TMR1 register did not overflow DS39770C-page 104 2010 Microchip Technology Inc. PIC18F85J90 FAMILY REGISTER 9-5: PIR2: PERIPHERAL INTERRUPT REQUEST (FLAG) REGISTER 2 R/W-0 R/W-0 U-0 U-0 R/W-0 R/W-0 R/W-0 U-0 OSCFIF CMIF -- -- BCLIF LVDIF TMR3IF -- bit 7 bit 0 Legend: R = Readable bit W = Writable bit U = Unimplemented bit, read as `0' -n = Value at POR `1' = Bit is set `0' = Bit is cleared x = Bit is unknown bit 7 OSCFIF: Oscillator Fail Interrupt Flag bit 1 = Device oscillator failed, clock input has changed to INTOSC (must be cleared in software) 0 = Device clock operating bit 6 CMIF: Comparator Interrupt Flag bit 1 = Comparator input has changed (must be cleared in software) 0 = Comparator input has not changed bit 5-4 Unimplemented: Read as `0' bit 3 BCLIF: Bus Collision Interrupt Flag bit 1 = A bus collision occurred (must be cleared in software) 0 = No bus collision occurred bit 2 LVDIF: Low-Voltage Detect Interrupt Flag bit 1 = A low-voltage condition occurred (must be cleared in software) 0 = The device voltage is above the regulator's low-voltage trip point bit 1 TMR3IF: TMR3 Overflow Interrupt Flag bit 1 = TMR3 register overflowed (must be cleared in software) 0 = TMR3 register did not overflow bit 0 Unimplemented: Read as `0' 2010 Microchip Technology Inc. DS39770C-page 105 PIC18F85J90 FAMILY REGISTER 9-6: PIR3: PERIPHERAL INTERRUPT REQUEST (FLAG) REGISTER 3 U-0 R/W-0 R-0 R-0 U-0 R/W-0 R/W-0 U-0 -- LCDIF RC2IF TX2IF -- CCP2IF CCP1IF -- bit 7 bit 0 Legend: R = Readable bit W = Writable bit U = Unimplemented bit, read as `0' -n = Value at POR `1' = Bit is set `0' = Bit is cleared x = Bit is unknown bit 7 Unimplemented: Read as `0' bit 6 LCDIF: LCD Interrupt Flag bit (valid when Type-B waveform with Non-Static mode is selected) 1 = LCD data of all COMs is output (must be cleared in software) 0 = LCD data of all COMs is not yet output bit 5 RC2IF: AUSART Receive Interrupt Flag bit 1 = The AUSART receive buffer, RCREG2, is full (cleared when RCREG2 is read) 0 = The AUSART receive buffer is empty bit 4 TX2IF: AUSART Transmit Interrupt Flag bit 1 = The AUSART transmit buffer, TXREG2, is empty (cleared when TXREG2 is written) 0 = The AUSART transmit buffer is full bit 3 Unimplemented: Read as `0' bit 2 CCP2IF: CCP2 Interrupt Flag bit Capture mode: 1 = A TMR1/TMR3 register capture occurred (must be cleared in software) 0 = No TMR1/TMR3 register capture occurred Compare mode: 1 = A TMR1/TMR3 register compare match occurred (must be cleared in software) 0 = No TMR1/TMR3 register compare match occurred PWM mode: Unused in this mode. bit 1 CCP1IF: CCP1 Interrupt Flag bit Capture mode: 1 = A TMR1/TMR3 register capture occurred (must be cleared in software) 0 = No TMR1/TMR3 register capture occurred Compare mode: 1 = A TMR1/TMR3 register compare match occurred (must be cleared in software) 0 = No TMR1/TMR3 register compare match occurred PWM mode: Unused in this mode. bit 0 Unimplemented: Read as `0' DS39770C-page 106 2010 Microchip Technology Inc. PIC18F85J90 FAMILY 9.3 PIE Registers The PIE registers contain the individual enable bits for the peripheral interrupts. Due to the number of peripheral interrupt sources, there are three Peripheral Interrupt Enable registers (PIE1, PIE2, PIE3). When IPEN = 0, the PEIE bit must be set to enable any of these peripheral interrupts. REGISTER 9-7: PIE1: PERIPHERAL INTERRUPT ENABLE REGISTER 1 U-0 R/W-0 R/W-0 R/W-0 R/W-0 U-0 R/W-0 R/W-0 -- ADIE RC1IE TX1IE SSPIE -- TMR2IE TMR1IE bit 7 bit 0 Legend: R = Readable bit W = Writable bit U = Unimplemented bit, read as `0' -n = Value at POR `1' = Bit is set `0' = Bit is cleared bit 7 Unimplemented: Read as `0' bit 6 ADIE: A/D Converter Interrupt Enable bit 1 = Enables the A/D interrupt 0 = Disables the A/D interrupt bit 5 RC1IE: EUSART Receive Interrupt Enable bit 1 = Enables the EUSART receive interrupt 0 = Disables the EUSART receive interrupt bit 4 TX1IE: EUSART Transmit Interrupt Enable bit 1 = Enables the EUSART transmit interrupt 0 = Disables the EUSART transmit interrupt bit 3 SSPIE: Master Synchronous Serial Port Interrupt Enable bit 1 = Enables the MSSP interrupt 0 = Disables the MSSP interrupt bit 2 Unimplemented: Read as `0' bit 1 TMR2IE: TMR2 to PR2 Match Interrupt Enable bit 1 = Enables the TMR2 to PR2 match interrupt 0 = Disables the TMR2 to PR2 match interrupt bit 0 TMR1IE: TMR1 Overflow Interrupt Enable bit 1 = Enables the TMR1 overflow interrupt 0 = Disables the TMR1 overflow interrupt 2010 Microchip Technology Inc. x = Bit is unknown DS39770C-page 107 PIC18F85J90 FAMILY REGISTER 9-8: PIE2: PERIPHERAL INTERRUPT ENABLE REGISTER 2 R/W-0 R/W-0 U-0 U-0 R/W-0 R/W-0 R/W-0 U-0 OSCFIE CMIE -- -- BCLIE LVDIE TMR3IE -- bit 7 bit 0 Legend: R = Readable bit W = Writable bit U = Unimplemented bit, read as `0' -n = Value at POR `1' = Bit is set `0' = Bit is cleared bit 7 OSCFIE: Oscillator Fail Interrupt Enable bit 1 = Enabled 0 = Disabled bit 6 CMIE: Comparator Interrupt Enable bit 1 = Enabled 0 = Disabled bit 5-4 Unimplemented: Read as `0' bit 3 BCLIE: Bus Collision Interrupt Enable bit 1 = Enabled 0 = Disabled bit 2 LVDIE: Low-Voltage Detect Interrupt Enable bit 1 = Enabled 0 = Disabled bit 1 TMR3IE: TMR3 Overflow Interrupt Enable bit 1 = Enabled 0 = Disabled bit 0 Unimplemented: Read as `0' DS39770C-page 108 x = Bit is unknown 2010 Microchip Technology Inc. PIC18F85J90 FAMILY REGISTER 9-9: PIE3: PERIPHERAL INTERRUPT ENABLE REGISTER 3 U-0 R/W-0 R-0 R-0 U-0 R/W-0 R/W-0 U-0 -- LCDIE RC2IE TX2IE -- CCP2IE CCP1IE -- bit 7 bit 0 Legend: R = Readable bit W = Writable bit U = Unimplemented bit, read as `0' -n = Value at POR `1' = Bit is set `0' = Bit is cleared x = Bit is unknown bit 7 Unimplemented: Read as `0' bit 6 LCDIE: LCD Interrupt Enable bit (valid when Type-B waveform with Non-Static mode is selected) 1 = Enabled 0 = Disabled bit 5 RC2IE: AUSART Receive Interrupt Enable bit 1 = Enabled 0 = Disabled bit 4 TX2IE: AUSART Transmit Interrupt Enable bit 1 = Enabled 0 = Disabled bit 3 Unimplemented: Read as `0' bit 2 CCP2IE: CCP2 Interrupt Enable bit 1 = Enabled 0 = Disabled bit 1 CCP1IE: CCP1 Interrupt Enable bit 1 = Enables the CCP1 interrupt 0 = Disables the CCP1 interrupt bit 0 Unimplemented: Read as `0' 2010 Microchip Technology Inc. DS39770C-page 109 PIC18F85J90 FAMILY 9.4 IPR Registers The IPR registers contain the individual priority bits for the peripheral interrupts. Due to the number of peripheral interrupt sources, there are three Peripheral Interrupt Priority registers (IPR1, IPR2, IPR3). Using the priority bits requires that the Interrupt Priority Enable (IPEN) bit be set. REGISTER 9-10: IPR1: PERIPHERAL INTERRUPT PRIORITY REGISTER 1 U-0 R/W-1 R/W-1 R/W-1 R/W-1 U-0 R/W-1 R/W-1 -- ADIP RC1IP TX1IP SSPIP -- TMR2IP TMR1IP bit 7 bit 0 Legend: R = Readable bit W = Writable bit U = Unimplemented bit, read as `0' -n = Value at POR `1' = Bit is set `0' = Bit is cleared bit 7 Unimplemented: Read as `0' bit 6 ADIP: A/D Converter Interrupt Priority bit 1 = High priority 0 = Low priority bit 5 RC1IP: EUSART Receive Interrupt Priority bit 1 = High priority 0 = Low priority bit 4 TX1IP: EUSART Transmit Interrupt Priority bit x = Bit is unknown 1 = High priority 0 = Low priority bit 3 SSPIP: Master Synchronous Serial Port Interrupt Priority bit 1 = High priority 0 = Low priority bit 2 Unimplemented: Read as `0' bit 1 TMR2IP: TMR2 to PR2 Match Interrupt Priority bit 1 = High priority 0 = Low priority bit 0 TMR1IP: TMR1 Overflow Interrupt Priority bit 1 = High priority 0 = Low priority DS39770C-page 110 2010 Microchip Technology Inc. PIC18F85J90 FAMILY REGISTER 9-11: IPR2: PERIPHERAL INTERRUPT PRIORITY REGISTER 2 R/W-1 R/W-1 U-0 U-0 R/W-1 R/W-1 R/W-1 U-0 OSCFIP CMIP -- -- BCLIP LVDIP TMR3IP -- bit 7 bit 0 Legend: R = Readable bit W = Writable bit U = Unimplemented bit, read as `0' -n = Value at POR `1' = Bit is set `0' = Bit is cleared bit 7 OSCFIP: Oscillator Fail Interrupt Priority bit 1 = High priority 0 = Low priority bit 6 CMIP: Comparator Interrupt Priority bit 1 = High priority 0 = Low priority bit 5-4 Unimplemented: Read as `0' bit 3 BCLIP: Bus Collision Interrupt Priority bit 1 = High priority 0 = Low priority bit 2 LVDIP: Low-Voltage Detect Interrupt Priority bit 1 = High priority 0 = Low priority bit 1 TMR3IP: TMR3 Overflow Interrupt Priority bit 1 = High priority 0 = Low priority bit 0 Unimplemented: Read as `0' 2010 Microchip Technology Inc. x = Bit is unknown DS39770C-page 111 PIC18F85J90 FAMILY REGISTER 9-12: IPR3: PERIPHERAL INTERRUPT PRIORITY REGISTER 3 U-0 R/W-1 R-1 R-1 U-0 R/W-1 R/W-1 U-0 -- LCDIP RC2IP TX2IP -- CCP2IP CCP1IP -- bit 7 bit 0 Legend: R = Readable bit W = Writable bit U = Unimplemented bit, read as `0' -n = Value at POR `1' = Bit is set `0' = Bit is cleared x = Bit is unknown bit 7 Unimplemented: Read as `0' bit 6 LCDIP: LCD Interrupt Priority bit (valid when Type-B waveform with Non-Static mode is selected) 1 = High priority 0 = Low priority bit 5 RC2IP: AUSART Receive Priority Flag bit 1 = High priority 0 = Low priority bit 4 TX2IP: AUSART Transmit Interrupt Priority bit 1 = High priority 0 = Low priority bit 3 Unimplemented: Read as `0' bit CCP2IP: CCP2 Interrupt Priority bit 1 = High priority 0 = Low priority bit CCP1IP: CCP1 Interrupt Priority bit 1 = High priority 0 = Low priority bit 0 Unimplemented: Read as `0' DS39770C-page 112 2010 Microchip Technology Inc. PIC18F85J90 FAMILY 9.5 RCON Register The RCON register contains bits used to determine the cause of the last Reset or wake-up from Idle or Sleep modes. RCON also contains the bit that enables interrupt priorities (IPEN). REGISTER 9-13: RCON: RESET CONTROL REGISTER R/W-0 U-0 R/W-1 R/W-1 R-1 R-1 R/W-0 R/W-0 IPEN -- CM RI TO PD POR BOR bit 7 bit 0 Legend: R = Readable bit W = Writable bit U = Unimplemented bit, read as `0' -n = Value at POR `1' = Bit is set `0' = Bit is cleared bit 7 IPEN: Interrupt Priority Enable bit 1 = Enable priority levels on interrupts 0 = Disable priority levels on interrupts (PIC16CXXX Compatibility mode) bit 6 Unimplemented: Read as `0' bit 5 CM: Configuration Mismatch Flag bit For details of bit operation, see Register 5-1. bit 4 RI: RESET Instruction Flag bit For details of bit operation, see Register 5-1. bit 3 TO: Watchdog Timer Time-out Flag bit For details of bit operation, see Register 5-1. bit 2 PD: Power-Down Detection Flag bit For details of bit operation, see Register 5-1. bit 1 POR: Power-on Reset Status bit For details of bit operation, see Register 5-1. bit 0 BOR: Brown-out Reset Status bit For details of bit operation, see Register 5-1. 2010 Microchip Technology Inc. x = Bit is unknown DS39770C-page 113 PIC18F85J90 FAMILY 9.6 INTx Pin Interrupts 9.7 External interrupts on the RB0/INT0, RB1/INT1, RB2/INT2 and RB3/INT3 pins are edge-triggered. If the corresponding INTEDGx bit in the INTCON2 register is set (= 1), the interrupt is triggered by a rising edge; if the bit is clear, the trigger is on the falling edge. When a valid edge appears on the RBx/INTx pin, the corresponding flag bit, INTxIF, is set. This interrupt can be disabled by clearing the corresponding enable bit, INTxIE. Flag bit, INTxIF, must be cleared in software in the Interrupt Service Routine before re-enabling the interrupt. All external interrupts (INT0, INT1, INT2 and INT3) can wake-up the processor from the power-managed modes if bit, INTxIE, was set prior to going into the power-managed modes. If the Global Interrupt Enable bit, GIE, is set, the processor will branch to the interrupt vector following wake-up. Interrupt priority for INT1, INT2 and INT3 is determined by the value contained in the interrupt priority bits, INT1IP (INTCON3<6>), INT2IP (INTCON3<7>) and INT3IP (INTCON2<1>). There is no priority bit associated with INT0. It is always a high-priority interrupt source. EXAMPLE 9-1: MOVWF MOVFF MOVFF ; ; USER ; MOVFF MOVF MOVFF TMR0 Interrupt In 8-bit mode (which is the default), an overflow in the TMR0 register (FFh 00h) will set flag bit, TMR0IF. In 16-bit mode, an overflow in the TMR0H:TMR0L register pair (FFFFh 0000h) will set TMR0IF. The interrupt can be enabled/disabled by setting/clearing enable bit, TMR0IE (INTCON<5>). Interrupt priority for Timer0 is determined by the value contained in the interrupt priority bit, TMR0IP (INTCON2<2>). See Section 11.0 "Timer0 Module" for further details on the Timer0 module. 9.8 PORTB Interrupt-on-Change An input change on PORTB<7:4> sets flag bit, RBIF (INTCON<0>). The interrupt can be enabled/disabled by setting/clearing enable bit, RBIE (INTCON<3>). Interrupt priority for the PORTB interrupt-on-change is determined by the value contained in the interrupt priority bit, RBIP (INTCON2<0>). 9.9 Context Saving During Interrupts During interrupts, the return PC address is saved on the stack. Additionally, the WREG, STATUS and BSR registers are saved on the Fast Return Stack. If a fast return from interrupt is not used (see Section 6.3 "Data Memory Organization"), the user may need to save the WREG, STATUS and BSR registers on entry to the Interrupt Service Routine. Depending on the user's application, other registers may also need to be saved. Example 9-1 saves and restores the WREG, STATUS and BSR registers during an Interrupt Service Routine. SAVING STATUS, WREG AND BSR REGISTERS IN RAM W_TEMP STATUS, STATUS_TEMP BSR, BSR_TEMP ; W_TEMP is in virtual bank ; STATUS_TEMP located anywhere ; BSR_TMEP located anywhere ISR CODE BSR_TEMP, BSR W_TEMP, W STATUS_TEMP, STATUS DS39770C-page 114 ; Restore BSR ; Restore WREG ; Restore STATUS 2010 Microchip Technology Inc. PIC18F85J90 FAMILY 10.0 I/O PORTS 10.1 Depending on the device selected and features enabled, there are up to nine ports available. Some pins of the I/O ports are multiplexed with an alternate function from the peripheral features on the device. In general, when a peripheral is enabled, that pin may not be used as a general purpose I/O pin. Each port has three memory mapped registers for its operation: I/O Port Pin Capabilities When developing an application, the capabilities of the port pins must be considered. Outputs on some pins have higher output drive strength than others. Similarly, some pins can tolerate higher than VDD input levels. 10.1.1 INPUT PINS AND VOLTAGE CONSIDERATIONS * TRIS register (Data Direction register) * PORT register (reads the levels on the pins of the device) * LAT register (Data Latch register) The voltage tolerance of pins used as device inputs is dependent on the pin's input function. Most pins that are used as digital only inputs are able to handle DC volta ges up to 5.5V, a level typical for digital logic circuits. The digital pins that cannot exceed VDD are RE0, RE1, RE2, RG0, RG2 and RG3. Reading the PORT register reads the current status of the pins, whereas writing to the PORT register writes to the Data Latch (LAT) register. In contrast, pins that also have analog input functions of any kind can only tolerate voltages up to VDD. Voltage excursions beyond VDD on these pins should be avoided. Setting a TRIS bit (= 1) makes the corresponding port pin an input (i.e., puts the corresponding output driver in a High-Impedance mode). Clearing a TRIS bit (= 0) makes the corresponding port pin an output (i.e., puts the contents of the corresponding LAT bit on the selected pin). Table 10-1 summarizes the input voltage capabilities. Refer to Section 26.0 "Electrical Characteristics" for more details. The Data Latch (LAT register) is useful for read-modify-write operations on the value that the I/O pins are driving. Read-modify-write operations on the LAT register read and write the latched output value for the PORT register. A simplified model of a generic I/O port, without the interfaces to other peripherals, is shown in Figure 10-1. FIGURE 10-1: GENERIC I/O PORT OPERATION RD LAT Data Bus D CKx WR TRIS Q CKx TRIS Latch Input Buffer RD TRIS Q D ENEN RD PORT Note 1: Tolerated Input Description Only VDD input levels PORTA<7:0> VDD are tolerated. PORTC<1:0> PORTF<7:1> PORTB<7:0> 5.5V Tolerates input levels above VDD; useful for PORTC<7:2> most standard logic. PORTD<7:0> PORTE<7:3> PORTG<4,1> PORTH<7:0>(1) PORTJ<7:0>(1) Note 1: Not available on 64-pin devices. 10.1.2 PIN OUTPUT DRIVE When used as digital I/O, the output pin drive strengths vary for groups of pins intended to meet the needs for a variety of applications. In general, there are three classes of output pins in terms of drive capability. Data Latch D PORT or Pin INPUT VOLTAGE TOLERANCE Q I/O pin(1) WR LAT or PORT TABLE 10-1: I/O pins have diode protection to VDD and VSS. 2010 Microchip Technology Inc. PORTB and PORTC, as well as PORTA<7:6>, are designed to drive higher current loads, such as LEDs. PORTD, PORTE and PORTJ can also drive LEDs but only those with smaller current requirements. PORTF, PORTG and PORTH, along with PORTA<5:0>, have the lowest drive level but are capable of driving normal digital circuit loads with a high input impedance. Regardless of which port it is located on, all output pins in LCD Segment or Common mode have sufficient output to directly drive a display. Table 10-2 summarizes the output capabilities of the ports. Refer to the "Absolute Maximum Ratings" in Section 26.0 "Electrical Characteristics" for more details. DS39770C-page 115 PIC18F85J90 FAMILY TABLE 10-2: OUTPUT DRIVE LEVELS FOR VARIOUS PORTS Low Medium High PORTA<5:0> PORTD PORTA<7:6> PORTF PORTE PORTB PORTG PORTJ (1) 10.1.3 Not available on 64-pin devices. PULL-UP CONFIGURATION Four of the I/O ports (PORTB, PORTD, PORTE and PORTJ) implement configurable weak pull-ups on all pins. These are internal pull-ups that allow floating digital input signals to be pulled to a consistent level without the use of external resistors. The pull-ups are enabled with a single bit for each of the ports: RBPU (INTCON2<7>) for PORTB, and RDPU, REPU and PJPU (PORTG<7:5>) for the other ports. 10.1.4 The output pins for several peripherals are also equipped with a configurable, open-drain output option. This allows the peripherals to communicate with external digital logic, operating at a higher voltage level, without the use of level translators. The open-drain option is implemented on port pins specifically associated with the data and clock outputs of the USARTs, the MSSP module (in SPI mode) and the CCP modules. This option is selectively enabled by setting the open-drain control bit for the corresponding module in TRISG and LATG. Their configuration is discussed in more detail in Section 10.4 "PORTC, TRISC and LATC Registers", Section 10.6 "PORTE, TRISE and LATE Registers" and Section 10.8 "PORTG, TRISG and LATG Registers". When the open-drain option is required, the output pin must also be tied through an external pull-up resistor provided by the user to a higher voltage level, up to 5V (Figure 10-2). When a digital logic high signal is output, it is pulled up to the higher voltage level. USING THE OPEN-DRAIN OUTPUT (USART SHOWN AS EXAMPLE) 3.3V PORTA is an 8-bit wide, bidirectional port. The corresponding Data Direction and Data Latch registers are TRISA and LATA. The RA4 pin is multiplexed with the Timer0 clock input and one of the LCD segment drives. RA5 and RA<3:0> are multiplexed with analog inputs for the A/D Converter. The operation of the analog inputs as A/D Converter inputs is selected by clearing or setting the PCFG<3:0> control bits in the ADCON1 register. The corresponding TRISA bits control the direction of these pins, even when they are being used as analog inputs. The user must ensure the bits in the TRISA register are maintained set when using them as analog inputs. Note: OPEN-DRAIN OUTPUTS FIGURE 10-2: RA1, RA4 and RA5 are multiplexed with LCD segment drives, controlled by bits in the LCDSE1 and LCDSE2 registers. I/O port functionality is only available when the LCD segments are disabled. EXAMPLE 10-1: CLRF CLRF MOVLW MOVWF MOVLW MOVWF PIC18F85J90 TXX (at logic `1') DS39770C-page 116 3.3V RA5 and RA<3:0> are configured as analog inputs on any Reset and are read as `0'. RA4 is configured as a digital input. OSC2/CLKO/RA6 and OSC1/CLKI/RA7 normally serve as the external circuit connections for the external (primary) oscillator circuit (HS Oscillator modes), or the external clock input and output (EC Oscillator modes). In these cases, RA6 and RA7 are not available as digital I/O and their corresponding TRIS and LAT bits are read as `0'. When the device is configured to use INTOSC or INTRC as the default oscillator mode (FOSC2 Configuration bit is `0'), RA6 and RA7 are automatically configured as digital I/O; the oscillator and clock in/clock out functions are disabled. +5V VDD PORTA, TRISA and LATA Registers RA4/T0CKI is a Schmitt Trigger input. All other PORTA pins have TTL input levels and full CMOS output drivers. PORTC PORTH(1) Note 1: 10.2 PORTA ; ; LATA ; ; 07h ; ADCON1 ; 0BFh ; ; TRISA ; ; INITIALIZING PORTA Initialize PORTA by clearing output latches Alternate method to clear output data latches Configure A/D for digital inputs Value used to initialize data direction Set RA<7, 5:0> as inputs, RA<6> as output 5V 2010 Microchip Technology Inc. PIC18F85J90 FAMILY TABLE 10-3: PORTA FUNCTIONS Pin Name Function TRIS Setting I/O I/O Type RA0 0 O DIG 1 I TTL PORTA<0> data input; disabled when analog input is enabled. AN0 1 I ANA A/D Input Channel 0. Default input configuration on POR; does not affect digital output. RA1 0 O DIG LATA<1> data output; not affected by analog input. 1 I TTL PORTA<1> data input; disabled when analog input enabled. AN1 1 I ANA A/D Input Channel 1. Default input configuration on POR; does not affect digital output. SEG18 x O ANA LCD Segment 18 output; disables all other pin functions. RA2 0 O DIG LATA<2> data output; not affected by analog input. 1 I TTL PORTA<2> data input; disabled when analog functions are enabled. RA0/AN0 RA1/AN1/SEG18 RA2/AN2/VREF- RA3/AN3/VREF+ RA4/T0CKI/ SEG14 I ANA A/D Input Channel 2. Default input configuration on POR. I ANA A/D and comparator low reference voltage input. RA3 0 O DIG LATA<3> data output; not affected by analog input. 1 I TTL PORTA<3> data input; disabled when analog input is enabled. AN3 1 I ANA A/D Input Channel 3. Default input configuration on POR. VREF+ 1 I ANA A/D and comparator high reference voltage input. RA4 0 O DIG LATA<4> data output. 1 I ST PORTA<4> data input. Default configuration on POR. I ST x O ANA Timer0 clock input. RA5 0 O DIG LATA<5> data output; not affected by analog input. 1 I TTL PORTA<5> data input; disabled when analog input is enabled. LCD Segment 14 output; disables all other pin functions. AN4 1 I ANA A/D Input Channel 4. Default configuration on POR. SEG15 x O ANA LCD Segment 15 output; disables all other pin functions. OSC2 x O ANA Main oscillator feedback output connection (HS and HSPLL modes). CLKO x O DIG System cycle clock output (FOSC/4) (EC and ECPLL modes). RA6 0 O DIG LATA<6> data output; disabled when FOSC2 Configuration bit is set. 1 I TTL PORTA<6> data input; disabled when FOSC2 Configuration bit is set. OSC1 x I ANA Main oscillator input connection (HS and HSPLL modes). CLKI x I ANA Main external clock source input (EC and ECPLL modes). RA7 0 O DIG LATA<7> data output; disabled when FOSC2 Configuration bit is set. 1 I TTL PORTA<7> data input; disabled when FOSC2 Configuration bit is set. O = Output, I = Input, ANA = Analog Signal, DIG = Digital Output, ST = Schmitt Trigger Buffer Input, TTL = TTL Buffer Input, x = Don't care (TRIS bit does not affect port direction or is overridden for this option). TABLE 10-4: LATA 1 1 x OSC1/CLKI/RA7 PORTA AN2 VREF- T0CKI OSC2/CLKO/RA6 Name LATA<0> data output; not affected by analog input. SEG14 RA5/AN4/SEG15 Legend: Description SUMMARY OF REGISTERS ASSOCIATED WITH PORTA Bit 7 Bit 6 RA7(1) RA6(1) RA5 RA4 RA3 RA2 LATA7(1) LATA6(1) LATA5 LATA4 LATA3 LATA2 (1) (1) Bit 4 Bit 3 Bit 2 Bit 0 Reset Values on page RA1 RA0 61 LATA1 LATA0 60 Bit 1 TRISA5 TRISA4 TRISA3 TRISA2 TRISA1 TRISA0 60 ADCON1 -- -- VCFG1 VCFG0 PCFG3 PCFG2 PCFG1 PCFG0 59 LCDSE1 SE15 SE14 SE13 SE12 SE11 SE10 SE09 SE08 59 LCDSE2 SE23 SE22 SE21 SE20 SE19 SE18 SE17 SE16 59 TRISA Legend: Note 1: TRISA7 TRISA6 Bit 5 -- = unimplemented, read as `0', x = don't care. Shaded cells are not used by PORTA. These bits are enabled depending on the oscillator mode selected. When not enabled as PORTA pins, they are disabled and read as `x'. 2010 Microchip Technology Inc. DS39770C-page 117 PIC18F85J90 FAMILY 10.3 PORTB, TRISB and LATB Registers PORTB is an 8-bit wide, bidirectional port. The corresponding Data Direction and Data Latch registers are TRISB and LATB. All pins on PORTB are digital only and tolerate voltages up to 5.5V. EXAMPLE 10-2: CLRF PORTB CLRF LATB MOVLW 0CFh MOVWF TRISB INITIALIZING PORTB ; ; ; ; ; ; ; ; ; ; ; ; Initialize PORTB by clearing output data latches Alternate method to clear output data latches Value used to initialize data direction Set RB<3:0> as inputs RB<5:4> as outputs RB<7:6> as inputs Each of the PORTB pins has a weak internal pull-up. A single control bit can turn on all the pull-ups. This is performed by clearing bit, RBPU (INTCON2<7>). The weak pull-up is automatically turned off when the port pin is configured as an output. The pull-ups are disabled on a Power-on Reset. Four of the PORTB pins (RB<7:4>) have an interrupt-on-change feature. Only pins configured as inputs can cause this interrupt to occur (i.e., any RB<7:4> pin configured as an output is excluded from the interrupt-on-change comparison). The input pins (of RB<7:4>) are compared with the old value latched on the last read of PORTB. The "mismatch" outputs of RB<7:4> are ORed together to generate the RB Port Change Interrupt with Flag bit, RBIF (INTCON<0>). This interrupt can wake the device from power-managed modes. The user, in the Interrupt Service Routine, can clear the interrupt in the following manner: a) b) c) Any read or write of PORTB (except with the MOVFF (ANY), PORTB instruction). This will end the mismatch condition. Wait one instruction cycle (such as executing a NOP instruction). Clear flag bit, RBIF. A mismatch condition will continue to set flag bit, RBIF. Reading PORTB will end the mismatch condition and allow flag bit, RBIF, to be cleared after one TCY delay. The interrupt-on-change feature is recommended for wake-up on key depression operation and operations where PORTB is only used for the interrupt-on-change feature. Polling of PORTB is not recommended while using the interrupt-on-change feature. RB<5:0> are also multiplexed with LCD segment drives, controlled by bits in the LCDSE1 and LCDSE3 registers. I/O port functionality is only available when the LCD segments are disabled. DS39770C-page 118 2010 Microchip Technology Inc. PIC18F85J90 FAMILY TABLE 10-5: Pin Name RB0/INT0/SEG30 RB1/INT1/SEG8 PORTB FUNCTIONS Function TRIS Setting I/O I/O Type RB0 0 O DIG 1 I TTL PORTB<0> data input; weak pull-up when RBPU bit is cleared. INT0 1 I ST External Interrupt 0 input. SEG30 x O ANA LCD Segment 30 output; disables all other pin functions. RB1 0 O DIG LATB<1> data output. 1 I TTL PORTB<1> data input; weak pull-up when RBPU bit is cleared. 1 I ST External Interrupt 1 input. INT1 RB2/INT2/SEG9 RB3/INT3/SEG10 RB4/KBI0/SEG11 RB5/KBI1/SEG29 RB7/KBI3/PGD Legend: LATB<0> data output. SEG8 x O ANA LCD Segment 8 output; disables all other pin functions. RB2 0 O DIG LATB<2> data output. 1 I TTL PORTB<2> data input; weak pull-up when RBPU bit is cleared. INT2 1 I ST SEG9 x O ANA LCD Segment 9 output; disables all other pin functions. RB3 0 O DIG LATB<3> data output. 1 I TTL PORTB<3> data input; weak pull-up when RBPU bit is cleared. INT3 1 I ST External Interrupt 3 input. SEG10 x O ANA LCD Segment 10 output; disables all other pin functions. RB4 0 O DIG LATB<4> data output. External Interrupt 2 input. PORTB<4> data input; weak pull-up when RBPU bit is cleared. 1 I TTL KBI0 1 I TTL Interrupt-on-pin change. SEG11 x O ANA LCD Segment 11 output; disables all other pin functions. RB5 0 O DIG LATB<5> data output. 1 I TTL PORTB<5> data input; weak pull-up when RBPU bit is cleared. 1 I TTL Interrupt-on-pin change. SEG29 x O ANA LCD Segment 29 output; disables all other pin functions. RB6 0 O DIG LATB<6> data output. 1 I TTL PORTB<6> data input; weak pull-up when RBPU bit is cleared. KBI2 1 I TTL Interrupt-on-pin change. PGC x I ST Serial execution (ICSPTM) clock input for ICSP and ICD operation. RB7 0 O DIG LATB<7> data output. PORTB<7> data input; weak pull-up when RBPU bit is cleared. KBI1 RB6/KBI2/PGC Description 1 I TTL KBI3 1 I TTL Interrupt-on-pin change. PGD x O DIG Serial execution data output for ICSP and ICD operation. x I ST Serial execution data input for ICSP and ICD operation. O = Output, I = Input, ANA = Analog Signal, DIG = Digital Output, ST = Schmitt Trigger Buffer Input, TTL = TTL Buffer Input, x = Don't care (TRIS bit does not affect port direction or is overridden for this option). 2010 Microchip Technology Inc. DS39770C-page 119 PIC18F85J90 FAMILY TABLE 10-6: Name PORTB LATB TRISB SUMMARY OF REGISTERS ASSOCIATED WITH PORTB Bit 7 Bit 6 Bit 5 Bit 4 Bit 3 Bit 2 Bit 1 Bit 0 Reset Values on page RB7 RB6 RB5 RB4 RB3 RB2 RB1 RB0 61 LATB7 LATB6 LATB5 LATB4 LATB3 LATB2 LATB1 LATB0 60 TRISB7 TRISB6 TRISB5 TRISB4 TRISB3 TRISB2 TRISB1 TRISB0 60 INTCON GIE/GIEH PEIE/GIEL TMR0IE INT0IE RBIE TMR0IF INT0IF RBIF 57 INTCON2 RBPU INTEDG0 INTEDG1 INTEDG2 INTEDG3 TMR0IP INT3IP RBIP 57 INTCON3 INT2IP INT1IP INT3IE INT2IE INT1IE INT3IF INT2IF INT1IF 57 LCDSE1 SE15 SE14 SE13 SE12 SE11 SE10 SE09 SE08 59 LCDSE3 SE31 SE30 SE29 SE28 SE27 SE26 SE25 SE24 59 Legend: Shaded cells are not used by PORTB. DS39770C-page 120 2010 Microchip Technology Inc. PIC18F85J90 FAMILY 10.4 PORTC, TRISC and LATC Registers PORTC is an 8-bit wide, bidirectional port. The corresponding Data Direction and Data Latch registers are TRISC and LATC. Only PORTC pins, RC2 through RC7, are digital only pins and can tolerate input voltages up to 5.5V. PORTC is multiplexed with CCP, MSSP and EUSART peripheral functions (Table 10-7). The pins have Schmitt Trigger input buffers. The pins for CCP, SPI and EUSART are also configurable for open-drain output whenever these functions are active. Open-drain configuration is selected by setting the SPIOD, CCPxOD, and U1OD control bits (TRISG<7:5> and LATG<6>, respectively). RC1 is normally configured as the default peripheral pin for the CCP2 module. Assignment of CCP2 is controlled by Configuration bit, CCP2MX (default state, CCP2MX = 1). When enabling peripheral functions, care should be taken in defining TRIS bits for each PORTC pin. Some peripherals override the TRIS bit to make a pin an output, while other peripherals override the TRIS bit to make a pin an input. The user should refer to the corresponding peripheral section for the correct TRIS bit settings. Note: The contents of the TRISC register are affected by peripheral overrides. Reading TRISC always returns the current contents, even though a peripheral device may be overriding one or more of the pins. RC<7:1> pins are multiplexed with LCD segment drives, controlled by bits in the LCDSE1, LCDSE2, LCDSE3 and LCDSE4 registers. I/O port functionality is only available when the LCD segments are disabled. EXAMPLE 10-3: CLRF PORTC CLRF LATC MOVLW 0CFh MOVWF TRISC INITIALIZING PORTC ; ; ; ; ; ; ; ; ; ; ; ; Initialize PORTC by clearing output data latches Alternate method to clear output data latches Value used to initialize data direction Set RC<3:0> as inputs RC<5:4> as outputs RC<7:6> as inputs These pins are configured as digital inputs on any device Reset. 2010 Microchip Technology Inc. DS39770C-page 121 PIC18F85J90 FAMILY TABLE 10-7: Pin Name RC0/T1OSO/ T13CKI RC1/T1OSI/ CCP2/SEG32 RC2/CCP1/ SEG13 PORTC FUNCTIONS Function TRIS Setting I/O I/O Type RC0 0 O DIG LATC<0> data output. 1 I ST PORTC<0> data input. T1OSO x O ANA T13CKI 1 I ST Timer1/Timer3 counter input. RC1 0 O DIG LATC<1> data output. 1 I ST PORTC<1> data input. T1OSI x I ANA Timer1 oscillator input. CCP2(1) 0 O DIG CCP2 compare/PWM output. 1 I ST SEG32 x O ANA LCD Segment 32 output; disables all other pin functions. RC2 0 O DIG LATC<2> data output. 1 I ST PORTC<2> data input. 0 O DIG CCP1 compare/PWM output; takes priority over port data. 1 I ST CCP1 capture input. SEG13 x O ANA LCD Segment 13 output; disables all other pin functions. RC3 0 O DIG LATC<3> data output. 1 I ST PORTC<3> data input. SCK 0 O DIG SPI clock output (MSSP module); takes priority over port data. 1 I ST SPI clock input (MSSP module). 0 O DIG I2CTM clock output (MSSP module); takes priority over port data. 1 I I2C I2C clock input (MSSP module); input type depends on module setting. CCP1 RC3/SCK/SCL/ SEG17 SCL RC4/SDI/SDA/ SEG16 RC7/RX1/DT1/ SEG28 x O ANA LCD Segment 17 output; disables all other pin functions. 0 O DIG LATC<4> data output. 1 I ST PORTC<4> data input. I ST SPI data input (MSSP module). 1 O DIG I2C data output (MSSP module); takes priority over port data. 1 I I2C I2C data input (MSSP module); input type depends on module setting. SEG16 x O ANA LCD Segment 16 output; disables all other pin functions. RC5 0 O DIG LATC<5> data output. 1 I ST PORTC<5> data input. SDO 0 O DIG SPI data output (MSSP module). SEG12 x O ANA LCD Segment 12 output; disables all other pin functions. RC6 0 O DIG LATC<6> data output. 1 I ST PORTC<6> data input. TX1 1 O DIG Synchronous serial data output (EUSART module); takes priority over port data. CK1 1 O DIG Synchronous serial data input (EUSART module); user must configure as an input. 1 I ST SEG27 x O ANA LCD Segment 27 output; disables all other pin functions. RC7 0 O DIG LATC<7> data output. 1 I ST PORTC<7> data input. Note 1: Synchronous serial clock input (EUSART module). RX1 1 I ST Asynchronous serial receive data input (EUSART module). DT1 1 O DIG Synchronous serial data output (EUSART module); takes priority over port data. 1 I ST Synchronous serial data input (EUSART module); user must configure as an input. x O ANA SEG28 Legend: CCP2 capture input. RC4 SDI RC6/TX1/CK1/ SEG27 Timer1 oscillator output; enabled when Timer1 oscillator is enabled. Disables digital I/O and LCD segment driver. SEG17 SDA RC5/SDO/ SEG12 Description LCD Segment 28 output; disables all other pin functions. O = Output, I = Input, ANA = Analog Signal, DIG = Digital Output, ST = Schmitt Trigger Buffer Input, TTL = TTL Buffer Input, I2C = I2C/SMBus Buffer Input, x = Don't care (TRIS bit does not affect port direction or is overridden for this option). Default assignment for CCP2 when the CCP2MX Configuration bit is set. DS39770C-page 122 2010 Microchip Technology Inc. PIC18F85J90 FAMILY TABLE 10-8: SUMMARY OF REGISTERS ASSOCIATED WITH PORTC Bit 7 Bit 6 Bit 5 Bit 4 Bit 3 Bit 2 Bit 1 Bit 0 Reset Values on page RC7 RC6 RC5 RC4 RC3 RC2 RC1 RC0 61 LATC LATC7 LATBC6 LATC5 LATCB4 LATC3 LATC2 LATC1 LATC0 60 TRISC TRISC7 TRISC6 TRISC5 TRISC4 TRISC3 TRISC2 TRISC1 TRISC0 60 U1OD -- Name PORTC LATG U2OD TRISG SPIOD CCP2OD CCP1OD LATG4 LATG3 LATG2 LATG1 LATG0 60 TRISG4 TRISG3 TRISG2 TRISG1 TRISG0 60 LCDSE1 SE15 SE14 SE13 SE12 SE11 SE10 SE09 SE08 59 LCDSE2 SE23 SE22 SE21 SE20 SE19 SE18 SE17 SE16 59 LCDSE3 SE31 SE30 SE29 SE28 SE27 SE26 SE25 SE24 59 SE32 59 LCDSE4 (1) SE39 (1) SE38 (1) SE37 SE36 (1) SE35 (1) SE34 (1) SE33 (1) Legend: Shaded cells are not used by PORTC. Note 1: Unimplemented on 64-pin devices, read as `0'. 2010 Microchip Technology Inc. DS39770C-page 123 PIC18F85J90 FAMILY 10.5 PORTD, TRISD and LATD Registers PORTD is an 8-bit wide, bidirectional port. The corresponding Data Direction and Data Latch registers are TRISD and LATD. All pins on PORTD are digital only and tolerate voltages up to 5.5V. All pins on PORTD are implemented with Schmitt Trigger input buffers. Each pin is individually configurable as an input or output. Note: These pins are configured as digital inputs on any device Reset. Each of the PORTD pins has a weak internal pull-up. A single control bit can turn off all the pull-ups. This is performed by clearing bit, RDPU (PORTG<7>). The weak pull-up is automatically turned off when the port pin is configured as an output. The pull-ups are disabled on all device Resets. DS39770C-page 124 All of the PORTD pins are multiplexed with LCD segment drives, controlled by bits in the LCDSE0 register. I/O port functionality is only available when the LCD segments are disabled. EXAMPLE 10-4: CLRF PORTD CLRF LATD MOVLW 0CFh MOVWF TRISD INITIALIZING PORTD ; ; ; ; ; ; ; ; ; ; ; ; Initialize PORTD by clearing output data latches Alternate method to clear output data latches Value used to initialize data direction Set RD<3:0> as inputs RD<5:4> as outputs RD<7:6> as inputs 2010 Microchip Technology Inc. PIC18F85J90 FAMILY TABLE 10-9: Pin Name RD0/SEG0 RD1/SEG1 RD2/SEG2 RD3/SEG3 RD4/SEG4 RD5/SEG5 RD6/SEG6 RD7/SEG7 PORTD FUNCTIONS Function TRIS Setting I/O I/O Type RD0 0 O DIG LATD<0> data output. 1 I ST PORTD<0> data input. SEG0 x O ANA LCD Segment 0 output; disables all other pin functions. RD1 0 O DIG LATD<1> data output. 1 I ST SEG1 x O ANA LCD Segment 1 output; disables all other pin functions. RD2 0 O DIG LATD<2> data output. 1 I ST SEG2 x O ANA LCD Segment 2 output; disables all other pin functions. RD3 0 O DIG LATD<3> data output. PORTD<1> data input. PORTD<2> data input. 1 I ST SEG3 x O ANA LCD Segment 3 output; disables all other pin functions. RD4 0 O DIG LATD<4> data output. 1 I ST PORTD<4> data input. SEG4 x O ANA LCD Segment 4 output; disables all other pin functions. RD5 0 O DIG LATD<5> data output. 1 I ST SEG5 x O ANA LCD Segment 5 output; disables all other pin functions. RD6 0 O DIG LATD<6> data output. 1 I ST SEG6 x O ANA LCD Segment 6 output; disables all other pin functions. RD7 0 O DIG LATD<7> data output. 1 I ST x I ANA SEG7 Legend: Description PORTD<3> data input. PORTD<5> data input. PORTD<6> data input. PORTD<7> data input. LCD Segment 7 output; disables all other pin functions. O = Output, I = Input, ANA = Analog Signal, DIG = Digital Output, ST = Schmitt Trigger Buffer Input, x = Don't care (TRIS bit does not affect port direction or is overridden for this option). TABLE 10-10: SUMMARY OF REGISTERS ASSOCIATED WITH PORTD Name PORTD Bit 7 Bit 6 Bit 5 Bit 4 Bit 3 Bit 2 Bit 1 Bit 0 Reset Values on page RD7 RD6 RD5 RD4 RD3 RD2 RD1 RD0 61 LATD LATD7 LATD6 LATD5 LATD4 LATD3 LATD2 LATD1 LATD0 60 TRISD TRISD7 TRISD6 TRISD5 TRISD4 TRISD3 TRISD2 TRISD1 TRISD0 60 PORTG RDPU REPU RJPU(1) RG4 RG3 RG2 RG1 RG0 60 LCDSE0 SE7 SE6 SE5 SE4 SE3 SE2 SE1 SE0 59 Legend: Shaded cells are not used by PORTD. Note 1: Unimplemented on 64-pin devices, read as `0'. 2010 Microchip Technology Inc. DS39770C-page 125 PIC18F85J90 FAMILY 10.6 PORTE, TRISE and LATE Registers PORTE is a 7-bit wide, bidirectional port. The corresponding Data Direction and Data Latch registers are TRISE and LATE. All pins on PORTE are digital only and tolerate voltages up to 5.5V. All pins on PORTE are implemented with Schmitt Trigger input buffers. Each pin is individually configurable as an input or output. The RE7 pin is also configurable for open-drain output when CCP2 is active on this pin. Open-drain configuration is selected by setting the CCP2OD control bit (TRISG<6>) Note: These pins are configured as digital inputs on any device Reset. Each of the PORTE pins has a weak internal pull-up. A single control bit can turn off all the pull-ups. This is performed by clearing bit, REPU (PORTG<6>). The weak pull-up is automatically turned off when the port pin is configured as an output. The pull-ups are disabled on any device Reset. Pins, RE<6:3>, are multiplexed with the LCD common drives. I/O port functions are only available on those PORTE pins depending on which commons are active. The configuration is determined by the LMUX<1:0> control bits (LCDCON<1:0>). The availability is summarized in Table 10-11. Pins, RE1 and RE0, are multiplexed with the functions of LCDBIAS2 and LCDBIAS1. When LCD bias generation is required (i.e., any application where the device is connected to an external LCD), these pins cannot be used as digital I/O. Note: The pin corresponding to RE2 of other PIC18F parts has the function of LCDBIAS3 in this device. It cannot be used as digital I/O. RE7 is multiplexed with LCD segment drive (SEG31) controlled by the LCDSE3<7> bit. I/O port function is only available when the segment is disabled. RE7 can also be configured as the alternate peripheral pin for the CCP2 module. This is done by clearing the CCP2MX Configuration bit. EXAMPLE 10-5: CLRF PORTE CLRF LATE MOVLW 03h MOVWF TRISE INITIALIZING PORTE ; ; ; ; ; ; ; ; ; ; ; Initialize PORTE by clearing output data latches Alternate method to clear output data latches Value used to initialize data direction Set RE<1:0> as inputs RE<7:2> as outputs TABLE 10-11: PORTE PINS AVAILABLE IN DIFFERENT LCD DRIVE CONFIGURATIONS LCDCON <1:0> Active LCD Commons PORTE Available for I/O 00 COM0 RE6, RE5, RE4 01 COM0, COM1 RE6, RE5 10 COM0, COM1 and COM2 RE6 11 All (COM0 through COM3) None DS39770C-page 126 2010 Microchip Technology Inc. PIC18F85J90 FAMILY TABLE 10-12: PORTE FUNCTIONS Pin Name Function TRIS Setting I/O I/O Type RE0/LCDBIAS1 RE0 0 O DIG LATE<0> data output. 1 I ST PORTE<0> data input. LCDBIAS1 -- I ANA LCD module bias voltage input. RE1 0 O DIG LATE<1> data output. 1 I ST PORTE<1> data input. RE1/LCDBIAS2 RE3/COM0 RE4/COM1 RE5/COM2 RE6/COM3 RE7/CCP2/ SEG31 LCDBIAS2 -- I ANA LCD module bias voltage input. RE3 0 O DIG LATE<3> data output. 1 I ST COM0 x O ANA LCD Common 0 output; disables all other outputs. RE4 0 O DIG LATE<4> data output. 1 I ST COM1 x O ANA LCD Common 1 output; disables all other outputs. RE5 0 O DIG LATE<5> data output. PORTE<4> data input. 1 I ST x O ANA LCD Common 2 output; disables all other outputs. RE6 0 O DIG LATE<6> data output. 1 I ST PORTE<6> data input. PORTE<5> data input. COM3 x O ANA LCD Common 3 output; disables all other outputs. RE7 0 O DIG LATE<7> data output. 1 I ST PORTE<7> data input. 0 O DIG CCP2 compare/PWM output; takes priority over port data. SEG31 Note 1: PORTE<3> data input. COM2 CCP2(1) Legend: Description 1 I ST x O ANA CCP2 capture input. Segment 31 analog output for LCD; disables digital output. O = Output, I = Input, ANA = Analog Signal, DIG = Digital Output, ST = Schmitt Trigger Buffer Input, x = Don't care (TRIS bit does not affect port direction or is overridden for this option). Alternate assignment for CCP2 when the CCP2MX Configuration bit is cleared. TABLE 10-13: SUMMARY OF REGISTERS ASSOCIATED WITH PORTE Name Bit 7 Bit 6 Bit 5 Bit 4 Bit 3 Bit 2 Bit 1 Bit 0 Reset Values on page RE7 RE6 RE5 RE4 RE3 -- RE1 RE0 61 LATE LATE7 LATE6 LATE5 LATE4 LATE3 -- LATE1 LATE0 60 TRISE TRISE7 TRISE6 TRISE5 TRISE4 TRISE3 -- TRISE1 TRISE0 60 PORTG RDPU REPU RJPU(1) RG4 RG3 RG2 RG1 RG0 60 TRISG SPIOD CCP2OD CCP1OD TRISG4 TRISG3 TRISG2 TRISG1 TRISG0 60 LCDCON LCDEN SLPEN WERR -- CS1 CS0 LMUX1 LMUX0 59 LCDSE3 SE31 SE30 SE29 SE28 SE27 SE26 SE25 SE24 59 PORTE Legend: Shaded cells are not used by PORTE. Note 1: Unimplemented on 64-pin devices, read as `0'. 2010 Microchip Technology Inc. DS39770C-page 127 PIC18F85J90 FAMILY 10.7 PORTF, LATF and TRISF Registers PORTF is a 7-bit wide, bidirectional port. The corresponding Data Direction and Data Latch registers are TRISF and LATF. All pins on PORTF are implemented with Schmitt Trigger input buffers. Each pin is individually configurable as an input or output. PORTF is multiplexed with analog peripheral functions, as well as LCD segments. Pins RF1 through RF6 may be used as comparator inputs or outputs by setting the appropriate bits in the CMCON register. To use RF<6:3> as digital inputs, it is also necessary to turn off the comparators. Note 1: On device Resets, pins, RF<6:1>, are configured as analog inputs and are read as `0'. 2: To configure PORTF as a digital I/O, turn off the comparators and set the ADCON1 value. DS39770C-page 128 PORTF is also multiplexed with LCD segment drives controlled by bits in the LCDSE2 and LCDSE3 registers. I/O port functions are only available when the segments are disabled. EXAMPLE 10-6: CLRF CLRF MOVLW MOVWF MOVLW MOVWF MOVLW MOVWF PORTF ; ; ; LATF ; ; ; 07h ; CMCON ; 0Fh ; ADCON1 ; 0CEh ; ; ; TRISF ; ; ; INITIALIZING PORTF Initialize PORTF by clearing output data latches Alternate method to clear output data latches Turn off comparators Set PORTF as digital I/O Value used to initialize data direction Set RF3:RF1 as inputs RF5:RF4 as outputs RF7:RF6 as inputs 2010 Microchip Technology Inc. PIC18F85J90 FAMILY TABLE 10-14: PORTF FUNCTIONS Pin Name Function TRIS Setting I/O I/O Type RF1/AN6/C2OUT/ SEG19 RF1 0 O DIG 1 I ST 1 I ANA AN6 RF2/AN7/C1OUT/ SEG20 RF3/AN8/SEG21 RF4/AN9/SEG22 RF5/AN10/CVREF/ SEG23 RF6/AN11/SEG24 RF7/AN5/SS/ SEG25 Legend: Description LATF<1> data output; not affected by analog input. PORTF<1> data input; disabled when analog input is enabled. A/D Input Channel 6. Default configuration on POR. C2OUT 0 O DIG Comparator 2 output; takes priority over port data. SEG19 x O ANA LCD Segment 19 output; disables all other pin functions. RF2 0 O DIG LATF<2> data output; not affected by analog input. 1 I ST AN7 1 I ANA A/D Input Channel 7. Default configuration on POR. C1OUT 0 O DIG Comparator 1 output; takes priority over port data. SEG20 x O ANA LCD Segment 20 output; disables all other pin functions. RF3 0 O DIG LATF<3> data output; not affected by analog input. 1 I ST PORTF<3> data input; disabled when analog input is enabled. AN8 1 I ANA A/D Input Channel 8 and Comparator C2+ input. Default input configuration on POR; not affected by analog output. SEG21 x O ANA LCD Segment 21 output; disables all other pin functions. RF4 0 O DIG LATF<4> data output; not affected by analog input. PORTF<2> data input; disabled when analog input is enabled. 1 I ST PORTF<4> data input; disabled when analog input is enabled. AN9 1 I ANA A/D Input Channel 9 and Comparator C2- input. Default input configuration on POR; does not affect digital output. SEG22 x O ANA LCD Segment 22 output; disables all other pin functions. RF5 0 O DIG LATF<5> data output; not affected by analog input. Disabled when CVREF output is enabled. 1 I ST PORTF<5> data input; disabled when analog input is enabled. Disabled when CVREF output is enabled. AN10 1 I ANA A/D Input Channel 10 and Comparator C1+ input. Default input configuration on POR. CVREF x O ANA Comparator voltage reference output. Enabling this feature disables digital I/O. SEG23 x O ANA LCD Segment 23 output; disables all other pin functions. RF6 0 O DIG LATF<6> data output; not affected by analog input. 1 I ST PORTF<6> data input; disabled when analog input is enabled. AN11 1 I ANA A/D Input Channel 11 and Comparator C1- input. Default input configuration on POR; does not affect digital output. SEG24 x O ANA LCD Segment 24 output; disables all other pin functions. RF7 0 O DIG LATF<7> data output; not affected by analog input. 1 I ST AN5 1 I ANA SS 1 I TTL Slave select input for MSSP module. SEG25 x O ANA LCD Segment 25 output; disables all other pin functions. PORTF<7> data input; disabled when analog input is enabled. A/D Input Channel 5. Default configuration on POR. O = Output, I = Input, ANA = Analog Signal, DIG = Digital Output, ST = Schmitt Trigger Buffer Input, TTL = TTL Buffer Input, x = Don't care (TRIS bit does not affect port direction or is overridden for this option). 2010 Microchip Technology Inc. DS39770C-page 129 PIC18F85J90 FAMILY TABLE 10-15: SUMMARY OF REGISTERS ASSOCIATED WITH PORTF Name PORTF Bit 7 Bit 6 Bit 5 Bit 4 Bit 3 Bit 2 Bit 1 Bit 0 Reset Values on page RF7 RF6 RF5 RF4 RF3 RF2 RF1 -- 60 60 60 LATF LATF7 LATF6 LATF5 LATF4 LATF3 LATF2 LATF1 -- TRISF TRISF7 TRISF6 TRISF5 TRISF4 TRISF3 TRISF2 TRISF1 -- ADCON1 -- -- VCFG1 VCFG0 PCFG3 PCFG2 PCFG1 PCFG0 59 CMCON C2OUT C1OUT C2INV C1INV CIS CM2 CM1 CM0 59 59 CVRCON CVREN CVROE CVRR CVRSS CVR3 CVR2 CVR1 CVR0 LCDSE2 SE23 SE22 SE21 SE20 SE19 SE18 SE17 SE16 59 LCDSE3 SE31 SE30 SE29 SE28 SE27 SE26 SE25 SE24 59 Legend: -- = unimplemented, read as `0'. Shaded cells are not used by PORTF. DS39770C-page 130 2010 Microchip Technology Inc. PIC18F85J90 FAMILY 10.8 PORTG, TRISG and LATG Registers PORTG is a 5-bit wide, bidirectional port. The corresponding Data Direction and Data Latch registers are TRISG and LATG. All pins on PORTG are digital only and tolerate voltages up to 5.5V. PORTG is multiplexed with both AUSART and LCD functions (Table 10-16). When operating as I/O, all PORTG pins have Schmitt Trigger input buffers. The RG1 pin is also configurable for open-drain output when the AUSART is active. Open-drain configuration is selected by setting the U2OD control bit (LATG<7>). RG4 is multiplexed with LCD segment drives controlled by bits in the LCDSE2 register. The I/O port function is only available when the segments are disabled. RG3 and RG2 are multiplexed with the VLCAP pins for the LCD charge pump and RG0 is multiplexed with the LCDBIAS0 bias voltage input. When these pins are used for LCD bias generation, the I/O and other functions are unavailable. When enabling peripheral functions, care should be taken in defining TRIS bits for each PORTG pin. Some peripherals override the TRIS bit to make a pin an output, while other peripherals override the TRIS bit to make a pin an input. The user should refer to the corresponding peripheral section for the correct TRIS bit settings. The pin override value is not loaded into the TRIS register. This allows read-modify-write of the TRIS register without concern due to peripheral overrides. 2010 Microchip Technology Inc. Although the port itself is only five bits wide, the PORTG<7:5> bits are still implemented to control the weak pull-ups on the I/O ports associated with PORTD, PORTE and PORTJ. Clearing these bits enables the respective port pull-ups. All pull-ups are disabled by default on all device Resets. Most of the corresponding TRISG and LATG bits are implemented as open-drain control bits for CCP1, CCP2 and SPI (TRISG<7:5>), and the USARTs (LATG<7:6>). Setting these bits configures the output pin for the corresponding peripheral for open-drain operation. LATG<5> is not implemented. EXAMPLE 10-7: CLRF PORTG CLRF LATG MOVLW 04h MOVWF TRISG INITIALIZING PORTG ; ; ; ; ; ; ; ; ; ; ; ; Initialize PORTG by clearing output data latches Alternate method to clear output data latches Value used to initialize data direction Set RG1:RG0 as outputs RG2 as input RG4:RG3 as inputs DS39770C-page 131 PIC18F85J90 FAMILY TABLE 10-16: PORTG FUNCTIONS Pin Name Function TRIS Setting I/O I/O Type RG0/LCDBIAS0 RG0 0 O DIG LATG<0> data output. 1 I ST LCDBIAS0 x I ANA LCD module bias voltage input. RG1 0 O DIG LATG<1> data output. 1 I ST PORTG<1> data input. TX2 1 O DIG Synchronous serial data output (AUSART module); takes priority over port data. CK2 1 O DIG Synchronous serial data input (AUSART module); user must configure as an input. 1 I ST Synchronous serial clock input (AUSART module). RG2 0 O DIG LATG<2> data output. PORTG<2> data input. RG1/TX2/CK2 RG2/RX2/DT2/V LCAP1 RG3/VLCAP2 RG4/SEG26 PORTG<0> data input. 1 I ST RX2 1 I ST Asynchronous serial receive data input (AUSART module). DT2 1 O DIG Synchronous serial data output (AUSART module); takes priority over port data. 1 I ST Synchronous serial data input (AUSART module); user must configure as an input. VLCAP1 x I ANA LCD charge pump capacitor input. RG3 0 O DIG LATG<3> data output. 1 I ST VLCAP2 x I ANA LCD charge pump capacitor input. RG4 0 O DIG LATG<4> data output. 1 I ST x O ANA SEG26 Legend: Description PORTG<3> data input. PORTG<4> data input. LCD Segment 26 output; disables all other pin functions. O = Output, I = Input, ANA = Analog Signal, DIG = Digital Output, ST = Schmitt Trigger Buffer Input, x = Don't care (TRIS bit does not affect port direction or is overridden for this option). TABLE 10-17: SUMMARY OF REGISTERS ASSOCIATED WITH PORTG Name PORTG Bit 7 Bit 6 Bit 5 Bit 4 Bit 3 Bit 2 Bit 1 Bit 0 Reset Values on page RDPU REPU RJPU(1) RG4 RG3 RG2 RG1 RG0 60 U1OD -- LATG4 LATG3 LATG2 LATG1 LATG0 60 CCP2OD CCP1OD TRISG4 TRISG3 TRISG2 TRISG1 TRISG0 60 SE27 SE26 SE25 SE24 59 LATG U2OD TRISG SPIOD LCDSE3 SE31 SE30 SE29 SE28 Legend: -- = unimplemented, read as `0'. Shaded cells are not used by PORTG. Note 1: Unimplemented on 64-pin devices, read as `0'. DS39770C-page 132 2010 Microchip Technology Inc. PIC18F85J90 FAMILY 10.9 Note: PORTH, LATH and TRISH Registers PORTH is available only on 80-pin devices. PORTH is an 8-bit wide, bidirectional I/O port. The corresponding Data Direction and Data Latch registers are TRISH and LATH. All pins are digital only and tolerate voltages up to 5.5V. All pins on PORTH are implemented with Schmitt Trigger input buffers. Each pin is individually configurable as an input or output. All PORTH pins are multiplexed with LCD segment drives controlled by the LCDSE5 register. I/O port functions are only available when the segments are disabled. 2010 Microchip Technology Inc. EXAMPLE 10-8: CLRF PORTH CLRF LATH MOVLW MOVWF MOVLW 0Fh ADCON1 0CFh MOVWF TRISH INITIALIZING PORTH ; ; ; ; ; ; ; ; ; ; ; ; ; ; Initialize PORTH by clearing output data latches Alternate method to clear output data latches Configure PORTH as digital I/O Value used to initialize data direction Set RH3:RH0 as inputs RH5:RH4 as outputs RH7:RH6 as inputs DS39770C-page 133 PIC18F85J90 FAMILY TABLE 10-18: PORTH FUNCTIONS Pin Name Function TRIS Setting I/O I/O Type RH0 0 O DIG RH0/SEG47 LATH<0> data output. 1 I ST SEG47 x O ANA LCD Segment 47 output; disables all other pin functions. RH1 0 O DIG LATH<1> data output. 1 I ST PORTH<1> data input. SEG46 x O ANA LCD Segment 46 output; disables all other pin functions. RH2 0 O DIG LATH<2> data output. 1 I ST SEG45 x O ANA LCD Segment 45 output; disables all other pin functions. RH3 0 O DIG LATH<3> data output. 1 I ST SEG44 x O ANA LCD Segment 44 output; disables all other pin functions. RH4 0 O DIG LATH<4> data output. RH1/SEG46 RH2/SEG45 RH3/SEG44 RH4/SEG40 PORTH<0> data input. PORTH<2> data input. PORTH<3> data input. 1 I ST SEG40 x O ANA LCD Segment 40 output; disables all other pin functions. RH5 0 O DIG LATH<5> data output. 1 I ST PORTH<5> data input. SEG41 x O ANA LCD Segment 41 output; disables all other pin functions. RH6 0 O DIG LATH<6> data output. 1 I ST SEG42 x O ANA LCD Segment 42 output; disables all other pin functions. RH7 0 O DIG LATH<7> data output. 1 I ST x O ANA RH5/SEG41 RH6/SEG42 RH7/SEG43 SEG43 Legend: Description PORTH<4> data input. PORTH<6> data input. PORTH<7> data input. LCD Segment 43 output; disables all other pin functions. O = Output, I = Input, ANA = Analog Signal, DIG = Digital Output, ST = Schmitt Trigger Buffer Input, x = Don't care (TRIS bit does not affect port direction or is overridden for this option). TABLE 10-19: SUMMARY OF REGISTERS ASSOCIATED WITH PORTH Name PORTH Bit 7 Bit 6 Bit 5 Bit 4 Bit 3 Bit 2 Bit 1 Bit 0 Reset Values on page RH7 RH6 RH5 RH4 RH3 RH2 RH1 RH0 60 LATH LATH7 LATH6 LATH5 LATH4 LATH3 LATH2 LATH1 LATH0 60 TRISH TRISH7 TRISH6 TRISH5 TRISH4 TRISH3 TRISH2 TRISH1 TRISH0 60 SE47 SE46 SE45 SE44 SE43 SE42 SE41 SE40 59 LCDSE5 DS39770C-page 134 2010 Microchip Technology Inc. PIC18F85J90 FAMILY 10.10 PORTJ, TRISJ and LATJ Registers Note: PORTJ is available only on 80-pin devices. PORTJ is an 8-bit wide, bidirectional port. The corresponding Data Direction and Data Latch registers are TRISJ and LATJ. All pins on PORTJ are digital only and tolerate voltages up to 5.5V. All pins on PORTJ are implemented with Schmitt Trigger input buffers. Each pin is individually configurable as an input or output. Note: These pins are configured as digital inputs on any device Reset. All PORTJ pins, except RJ0, are multiplexed with LCD segment drives controlled by the LCDSE4 register. I/O port functions are only available on these pins when the segments are disabled. 2010 Microchip Technology Inc. Each of the PORTJ pins has a weak internal pull-up. The pull-ups are provided to keep the inputs at a known state for the external memory interface while powering up. A single control bit can turn off all the pull-ups. This is performed by clearing bit RJPU (PORTG<5>). The weak pull-up is automatically turned off when the port pin is configured as an output. The pull-ups are disabled on any device Reset. EXAMPLE 10-9: CLRF PORTJ CLRF LATJ MOVLW 0CFh MOVWF TRISJ INITIALIZING PORTJ ; ; ; ; ; ; ; ; ; ; Initialize PORTJ by clearing output latches Alternate method to clear output latches Value used to initialize data direction Set RJ3:RJ0 as inputs RJ5:RJ4 as output RJ7:RJ6 as inputs DS39770C-page 135 PIC18F85J90 FAMILY TABLE 10-20: PORTJ FUNCTIONS Function TRIS Setting I/O I/O Type RJ0 RJ0 0 O DIG RJ1/SEG33 RJ1 Pin Name LATJ<0> data output. 1 I ST PORTJ<0> data input. 0 O DIG LATJ<1> data output. 1 I ST SEG33 x O ANA LCD Segment 33 output; disables all other pin functions. RJ2 0 O DIG LATJ<2> data output. 1 I ST SEG34 x O ANA LCD Segment 34 output; disables all other pin functions. RJ3 0 O DIG LATJ<3> data output. RJ2/SEG34 RJ3/SEG35 PORTJ<1> data input. PORTJ<2> data input. 1 I ST SEG35 x O ANA LCD Segment 35 output; disables all other pin functions. RJ4 0 O DIG LATJ<4> data output. 1 I ST PORTJ<4> data input. SEG39 x O ANA LCD Segment 39 output; disables all other pin functions. RJ5 0 O DIG LATJ<5> data output. 1 I ST SEG38 x O ANA LCD Segment 38 output; disables all other pin functions. RJ6 0 O DIG LATJ<6> data output. 1 I ST SEG37 x O ANA LCD Segment 37 output; disables all other pin functions. RJ7 0 O DIG LATJ<7> data output. RJ4/SEG39 RJ5/SEG38 RJ6/SEG37 RJ7/SEG36 SEG36 Legend: Description PORTJ<3> data input. PORTJ<5> data input. PORTJ<6> data input. 1 I ST x O ANA PORTJ<7> data input. LCD Segment 36 output; disables all other pin functions. O = Output, I = Input, ANA = Analog Signal, DIG = Digital Output, ST = Schmitt Trigger Buffer Input, x = Don't care (TRIS bit does not affect port direction or is overridden for this option). TABLE 10-21: SUMMARY OF REGISTERS ASSOCIATED WITH PORTJ Name PORTJ Bit 7 Bit 6 Bit 5 Bit 4 Bit 3 Bit 2 Bit 1 Bit 0 Reset Values on page RJ7 RJ6 RJ5 RJ4 RJ3 RJ2 RJ1 RJ0 60 60 LATJ LATJ7 LATJ6 LATJ5 LATJ4 LATJ3 LATJ2 LATJ1 LATJ0 TRISJ TRISJ7 TRISJ6 TRISJ5 TRISJ4 TRISJ3 TRISJ2 TRISJ1 TRISJ0 60 PORTG RDPU REPU RJPU(1) RG4 RG3 RG2 RG1 RG0 60 LCDSE4 SE39 SE38 SE37 SE36 SE35 SE34 SE33 SE32 59 Legend: Shaded cells are not used by PORTJ. Note 1: Unimplemented on 64-pin devices, read as `0'. DS39770C-page 136 2010 Microchip Technology Inc. PIC18F85J90 FAMILY 11.0 TIMER0 MODULE The Timer0 module incorporates the following features: * Software selectable operation as a timer or counter in both 8-bit or 16-bit modes * Readable and writable registers * Dedicated 8-bit, software programmable prescaler * Selectable clock source (internal or external) * Edge select for external clock * Interrupt-on-overflow REGISTER 11-1: The T0CON register (Register 11-1) controls all aspects of the module's operation, including the prescale selection; it is both readable and writable. A simplified block diagram of the Timer0 module in 8-bit mode is shown in Figure 11-1. Figure 11-2 shows a simplified block diagram of the Timer0 module in 16-bit mode. T0CON: TIMER0 CONTROL REGISTER R/W-1 R/W-1 R/W-1 R/W-1 R/W-1 R/W-1 R/W-1 R/W-1 TMR0ON T08BIT T0CS T0SE PSA T0PS2 T0PS1 T0PS0 bit 7 bit 0 Legend: R = Readable bit W = Writable bit U = Unimplemented bit, read as `0' -n = Value at POR `1' = Bit is set `0' = Bit is cleared x = Bit is unknown bit 7 TMR0ON: Timer0 On/Off Control bit 1 = Enables Timer0 0 = Stops Timer0 bit 6 T08BIT: Timer0 8-Bit/16-Bit Control bit 1 = Timer0 is configured as an 8-bit timer/counter 0 = Timer0 is configured as a 16-bit timer/counter bit 5 T0CS: Timer0 Clock Source Select bit 1 = Transition on T0CKI pin input edge 0 = Internal clock (FOSC/4) bit 4 T0SE: Timer0 Source Edge Select bit 1 = Increment on high-to-low transition on T0CKI pin 0 = Increment on low-to-high transition on T0CKI pin bit 3 PSA: Timer0 Prescaler Assignment bit 1 = TImer0 prescaler is not assigned. Timer0 clock input bypasses prescaler. 0 = Timer0 prescaler is assigned. Timer0 clock input comes from prescaler output. bit 2-0 T0PS<2:0>: Timer0 Prescaler Select bits 111 = 1:256 Prescale value 110 = 1:128 Prescale value 101 = 1:64 Prescale value 100 = 1:32 Prescale value 011 = 1:16 Prescale value 010 = 1:8 Prescale value 001 = 1:4 Prescale value 000 = 1:2 Prescale value 2010 Microchip Technology Inc. DS39770C-page 137 PIC18F85J90 FAMILY 11.1 Timer0 Operation internal phase clock (TOSC). There is a delay between synchronization and the onset of incrementing the timer/counter. Timer0 can operate as either a timer or a counter. The mode is selected with the T0CS bit (T0CON<5>). In Timer mode (T0CS = 0), the module increments on every clock by default unless a different prescaler value is selected (see Section 11.3 "Prescaler"). If the TMR0 register is written to, the increment is inhibited for the following two instruction cycles. The user can work around this by writing an adjusted value to the TMR0 register. 11.2 TMR0H is not the actual high byte of Timer0 in 16-bit mode. It is actually a buffered version of the real high byte of Timer0, which is not directly readable nor writable (refer to Figure 11-2). TMR0H is updated with the contents of the high byte of Timer0 during a read of TMR0L. This provides the ability to read all 16 bits of Timer0 without having to verify that the read of the high and low byte were valid, due to a rollover between successive reads of the high and low byte. The Counter mode is selected by setting the T0CS bit (= 1). In this mode, Timer0 increments either on every rising or falling edge of pin RA4/T0CKI. The incrementing edge is determined by the Timer0 Source Edge Select bit, T0SE (T0CON<4>); clearing this bit selects the rising edge. Restrictions on the external clock input are discussed below. Similarly, a write to the high byte of Timer0 must also take place through the TMR0H Buffer register. The high byte is updated with the contents of TMR0H when a write occurs to TMR0L. This allows all 16 bits of Timer0 to be updated at once. An external clock source can be used to drive Timer0, however, it must meet certain requirements to ensure that the external clock can be synchronized with the FIGURE 11-1: Timer0 Reads and Writes in 16-Bit Mode TIMER0 BLOCK DIAGRAM (8-BIT MODE) FOSC/4 0 1 1 Programmable Prescaler T0CKI pin T0SE T0CS 0 Sync with Internal Clocks (2 TCY Delay) 8 3 T0PS<2:0> 8 PSA Note: Set TMR0IF on Overflow TMR0L Internal Data Bus Upon Reset, Timer0 is enabled in 8-bit mode with clock input from T0CKI max. prescale. FIGURE 11-2: FOSC/4 TIMER0 BLOCK DIAGRAM (16-BIT MODE) 0 1 1 T0CKI pin T0SE T0CS Programmable Prescaler 0 Sync with Internal Clocks TMR0 High Byte TMR0L 8 Set TMR0IF on Overflow (2 TCY Delay) 3 Read TMR0L T0PS<2:0> Write TMR0L PSA 8 8 TMR0H 8 8 Internal Data Bus Note: Upon Reset, Timer0 is enabled in 8-bit mode with clock input from T0CKI max. prescale. DS39770C-page 138 2010 Microchip Technology Inc. PIC18F85J90 FAMILY 11.3 Prescaler 11.3.1 An 8-bit counter is available as a prescaler for the Timer0 module. The prescaler is not directly readable or writable. Its value is set by the PSA and T0PS<2:0> bits (T0CON<3:0>) which determine the prescaler assignment and prescale ratio. Clearing the PSA bit assigns the prescaler to the Timer0 module. When it is assigned, prescale values from 1:2 through 1:256, in power-of-2 increments, are selectable. When assigned to the Timer0 module, all instructions writing to the TMR0 register (e.g., CLRF TMR0, MOVWF TMR0, BSF TMR0, etc.) clear the prescaler count. Note: Writing to TMR0 when the prescaler is assigned to Timer0 will clear the prescaler count but will not change the prescaler assignment. TABLE 11-1: Name SWITCHING PRESCALER ASSIGNMENT The prescaler assignment is fully under software control and can be changed "on-the-fly" during program execution. 11.4 Timer0 Interrupt The TMR0 interrupt is generated when the TMR0 register overflows from FFh to 00h in 8-bit mode, or from FFFFh to 0000h in 16-bit mode. This overflow sets the TMR0IF flag bit. The interrupt can be masked by clearing the TMR0IE bit (INTCON<5>). Before re-enabling the interrupt, the TMR0IF bit must be cleared in software by the Interrupt Service Routine. Since Timer0 is shut down in Sleep mode, the TMR0 interrupt cannot awaken the processor from Sleep. REGISTERS ASSOCIATED WITH TIMER0 Bit 7 Bit 6 Bit 5 TMR0L Timer0 Register Low Byte TMR0H Timer0 Register High Byte INTCON GIE/GIEH PEIE/GIEL TMR0IE T0CON TMR0ON TRISA TRISA7(1) TRISA6(1) T08BIT Bit 4 Bit 3 Bit 2 Bit 1 Bit 0 Reset Values on page 58 58 INT0IE RBIE TMR0IF INT0IF RBIF 57 T0CS T0SE PSA T0PS2 T0PS1 T0PS0 58 TRISA5 TRISA4 TRISA3 TRISA2 TRISA1 TRISA0 60 Legend: -- = unimplemented, read as `0'. Shaded cells are not used by Timer0. Note 1: RA6/RA7 and their associated latch and direction bits are configured as port pins only when the internal oscillator is selected as the default clock source (FOSC2 Configuration bit = 0); otherwise, they are disabled and these bits read as `0'. 2010 Microchip Technology Inc. DS39770C-page 139 PIC18F85J90 FAMILY NOTES: DS39770C-page 140 2010 Microchip Technology Inc. PIC18F85J90 FAMILY 12.0 TIMER1 MODULE The Timer1 timer/counter module incorporates these features: * Software selectable operation as a 16-bit timer or counter * Readable and writable 8-bit registers (TMR1H and TMR1L) * Selectable clock source (internal or external) with device clock or Timer1 oscillator internal options * Interrupt on overflow * Reset on CCP Special Event Trigger * Device clock status flag (T1RUN) REGISTER 12-1: A simplified block diagram of the Timer1 module is shown in Figure 12-1. A block diagram of the module's operation in Read/Write mode is shown in Figure 12-2. The module incorporates its own low-power oscillator to provide an additional clocking option. The Timer1 oscillator can also be used as a low-power clock source for the microcontroller in power-managed operation. Timer1 can also be used to provide Real-Time Clock (RTC) functionality to applications with only a minimal addition of external components and code overhead. Timer1 is controlled through the T1CON Control register (Register 12-1). It also contains the Timer1 Oscillator Enable bit (T1OSCEN). Timer1 can be enabled or disabled by setting or clearing control bit, TMR1ON (T1CON<0>). T1CON: TIMER1 CONTROL REGISTER R/W-0 R-0 R/W-0 R/W-0 R/W-0 R/W-0 R/W-0 R/W-0 RD16 T1RUN T1CKPS1 T1CKPS0 T1OSCEN T1SYNC TMR1CS TMR1ON bit 7 bit 0 Legend: R = Readable bit W = Writable bit U = Unimplemented bit, read as `0' -n = Value at POR `1' = Bit is set `0' = Bit is cleared x = Bit is unknown bit 7 RD16: 16-Bit Read/Write Mode Enable bit 1 = Enables register read/write of TImer1 in one 16-bit operation 0 = Enables register read/write of Timer1 in two 8-bit operations bit 6 T1RUN: Timer1 System Clock Status bit 1 = Device clock is derived from Timer1 oscillator 0 = Device clock is derived from another source bit 5-4 T1CKPS<1:0>: Timer1 Input Clock Prescale Select bits 11 = 1:8 Prescale value 10 = 1:4 Prescale value 01 = 1:2 Prescale value 00 = 1:1 Prescale value bit 3 T1OSCEN: Timer1 Oscillator Enable bit 1 = Timer1 oscillator is enabled 0 = Timer1 oscillator is shut off The oscillator inverter and feedback resistor are turned off to eliminate power drain. bit 2 T1SYNC: Timer1 External Clock Input Synchronization Select bit When TMR1CS = 1: 1 = Do not synchronize external clock input 0 = Synchronize external clock input When TMR1CS = 0: This bit is ignored. Timer1 uses the internal clock when TMR1CS = 0. bit 1 TMR1CS: Timer1 Clock Source Select bit 1 = External clock from pin RC0/T1OSO/T13CKI (on the rising edge) 0 = Internal clock (FOSC/4) bit 0 TMR1ON: Timer1 On bit 1 = Enables Timer1 0 = Stops Timer1 2010 Microchip Technology Inc. DS39770C-page 141 PIC18F85J90 FAMILY 12.1 Timer1 Operation cycle (FOSC/4). When the bit is set, Timer1 increments on every rising edge of the Timer1 external clock input or the Timer1 oscillator, if enabled. Timer1 can operate in one of these modes: * Timer * Synchronous Counter * Asynchronous Counter When Timer1 is enabled, the RC1/T1OSI and RC0/T1OSO/T13CKI pins become inputs. This means the values of TRISC<1:0> are ignored and the pins are read as `0'. The operating mode is determined by the clock select bit, TMR1CS (T1CON<1>). When TMR1CS is cleared (= 0), Timer1 increments on every internal instruction FIGURE 12-1: TIMER1 BLOCK DIAGRAM (8-BIT MODE) Timer1 Oscillator Timer1 Clock Input On/Off T1OSO/T13CKI 1 1 FOSC/4 Internal Clock T1OSI Synchronize Prescaler 1, 2, 4, 8 0 2 T1OSCEN(1) 0 Detect Sleep Input TMR1CS Timer1 On/Off T1CKPS<1:0> T1SYNC TMR1ON Clear TMR1 (CCP Special Event Trigger) Set TMR1IF on Overflow TMR1 High Byte TMR1L Note 1: When enable bit, T1OSCEN, is cleared, the inverter and feedback resistor are turned off to eliminate power drain. FIGURE 12-2: TIMER1 BLOCK DIAGRAM (16-BIT READ/WRITE MODE) Timer1 Oscillator Timer1 Clock Input 1 T1OSO/T13CKI 1 FOSC/4 Internal Clock T1OSI Synchronize Prescaler 1, 2, 4, 8 0 2 T1OSCEN(1) T1CKPS<1:0> T1SYNC TMR1ON 0 Detect Sleep Input TMR1CS Clear TMR1 (CCP Special Event Trigger) Timer1 On/Off TMR1 High Byte TMR1L 8 Set TMR1IF on Overflow Read TMR1L Write TMR1L 8 8 TMR1H 8 8 Internal Data Bus Note 1: When enable bit, T1OSCEN, is cleared, the inverter and feedback resistor are turned off to eliminate power drain. DS39770C-page 142 2010 Microchip Technology Inc. PIC18F85J90 FAMILY 12.2 Timer1 16-Bit Read/Write Mode Timer1 can be configured for 16-bit reads and writes (see Figure 12-2). When the RD16 control bit (T1CON<7>) is set, the address for TMR1H is mapped to a buffer register for the high byte of Timer1. A read from TMR1L will load the contents of the high byte of Timer1 into the Timer1 High Byte Buffer register. This provides the user with the ability to accurately read all 16 bits of Timer1 without having to determine whether a read of the high byte, followed by a read of the low byte, has become invalid due to a rollover between reads. TABLE 12-1: Oscillator Type Freq. C1 C2 LP 32.768 kHz 27 pF(1) 27 pF(1) Note 1: Microchip suggests these values as a starting point in validating the oscillator circuit. 2: Higher capacitance increases the stability of the oscillator but also increases the start-up time. A write to the high byte of Timer1 must also take place through the TMR1H Buffer register. The Timer1 high byte is updated with the contents of TMR1H when a write occurs to TMR1L. This allows a user to write all 16 bits to both the high and low bytes of Timer1 at once. The high byte of Timer1 is not directly readable or writable in this mode. All reads and writes must take place through the Timer1 High Byte Buffer register. Writes to TMR1H do not clear the Timer1 prescaler. The prescaler is only cleared on writes to TMR1L. 12.3 Timer1 Oscillator An on-chip crystal oscillator circuit is incorporated between pins T1OSI (input) and T1OSO (amplifier output). It is enabled by setting the Timer1 Oscillator Enable bit, T1OSCEN (T1CON<3>). The oscillator is a low-power circuit rated for 32 kHz crystals. It will continue to run during all power-managed modes. The circuit for a typical LP oscillator is shown in Figure 12-3. Table 12-1 shows the capacitor selection for the Timer1 oscillator. The user must provide a software time delay to ensure proper start-up of the Timer1 oscillator. FIGURE 12-3: EXTERNAL COMPONENTS FOR THE TIMER1 LP OSCILLATOR C1 27 pF PIC18F85J90 CAPACITOR SELECTION FOR THE TIMER1 OSCILLATOR(2,3,4) 3: Since each resonator/crystal has its own characteristics, the user should consult the resonator/crystal manufacturer for appropriate values of external components. 4: Capacitor values are for design guidance only. 12.3.1 USING TIMER1 AS A CLOCK SOURCE The Timer1 oscillator is also available as a clock source in power-managed modes. By setting the System Clock Select bits, SCS<1:0> (OSCCON<1:0>), to `01', the device switches to SEC_RUN mode; both the CPU and peripherals are clocked from the Timer1 oscillator. If the IDLEN bit (OSCCON<7>) is cleared and a SLEEP instruction is executed, the device enters SEC_IDLE mode. Additional details are available in Section 4.0 "Power-Managed Modes". Whenever the Timer1 oscillator is providing the clock source, the Timer1 system clock status flag, T1RUN (T1CON<6>), is set. This can be used to determine the controller's current clocking mode. It can also indicate the clock source being currently used by the Fail-Safe Clock Monitor. If the Clock Monitor is enabled and the Timer1 oscillator fails while providing the clock, polling the T1RUN bit will indicate whether the clock is being provided by the Timer1 oscillator or another source. T1OSI XTAL 32.768 kHz T1OSO C2 27 pF Note: See the Notes with Table 12-1 for additional information about capacitor selection. 2010 Microchip Technology Inc. DS39770C-page 143 PIC18F85J90 FAMILY 12.3.2 TIMER1 OSCILLATOR LAYOUT CONSIDERATIONS The Timer1 oscillator circuit draws very little power during operation. Due to the low-power nature of the oscillator, it may also be sensitive to rapidly changing signals in close proximity. The oscillator circuit, shown in Figure 12-3, should be located as close as possible to the microcontroller. There should be no circuits passing within the oscillator circuit boundaries other than VSS or VDD. If a high-speed circuit must be located near the oscillator (such as the CCP1 pin in Output Compare or PWM mode, or the primary oscillator using the OSC2 pin), a grounded guard ring around the oscillator circuit, as shown in Figure 12-4, may be helpful when used on a single-sided PCB or in addition to a ground plane. FIGURE 12-4: OSCILLATOR CIRCUIT WITH GROUNDED GUARD RING 12.5 Resetting Timer1 Using the CCP Special Event Trigger If CCP1 or CCP2 is configured to use Timer1 and to generate a Special Event Trigger in Compare mode (CCPxM<3:0> = 1011), this signal will reset Timer3. The trigger from CCP2 will also start an A/D conversion if the A/D module is enabled (see Section 15.3.4 "Special Event Trigger" for more information). The module must be configured as either a timer or a synchronous counter to take advantage of this feature. When used this way, the CCPRxH:CCPRxL register pair effectively becomes a period register for Timer1. If Timer1 is running in Asynchronous Counter mode, this Reset operation may not work. In the event that a write to Timer1 coincides with a Special Event Trigger, the write operation will take precedence. Note: The Special Event Triggers from the CCPx module will not set the TMR1IF interrupt flag bit (PIR1<0>). VDD VSS OSC1 OSC2 RC0 RC1 RC2 Note: Not drawn to scale. 12.4 Timer1 Interrupt The TMR1 register pair (TMR1H:TMR1L) increments from 0000h to FFFFh and rolls over to 0000h. The Timer1 interrupt, if enabled, is generated on overflow which is latched in interrupt flag bit, TMR1IF (PIR1<0>). This interrupt can be enabled or disabled by setting or clearing the Timer1 Interrupt Enable bit, TMR1IE (PIE1<0>). 12.6 Using Timer1 as a Real-Time Clock Adding an external LP oscillator to Timer1 (such as the one described in Section 12.3 "Timer1 Oscillator") gives users the option to include RTC functionality to their applications. This is accomplished with an inexpensive watch crystal to provide an accurate time base and several lines of application code to calculate the time. When operating in Sleep mode and using a battery or supercapacitor as a power source, it can completely eliminate the need for a separate RTC device and battery backup. The application code routine, RTCisr, shown in Example 12-1, demonstrates a simple method to increment a counter at one-second intervals using an Interrupt Service Routine. Incrementing the TMR1 register pair to overflow triggers the interrupt and calls the routine which increments the seconds counter by one. Additional counters for minutes and hours are incremented as the previous counter overflows. Since the register pair is 16 bits wide, counting up to overflow the register directly from a 32.768 kHz clock would take 2 seconds. To force the overflow at the required one-second intervals, it is necessary to preload it. The simplest method is to set the MSb of TMR1H with a BSF instruction. Note that the TMR1L register is never preloaded or altered; doing so may introduce cumulative error over many cycles. For this method to be accurate, Timer1 must operate in Asynchronous mode and the Timer1 overflow interrupt must be enabled (PIE1<0> = 1) as shown in the routine, RTCinit. The Timer1 oscillator must also be enabled and running at all times. DS39770C-page 144 2010 Microchip Technology Inc. PIC18F85J90 FAMILY EXAMPLE 12-1: IMPLEMENTING A REAL-TIME CLOCK USING A TIMER1 INTERRUPT SERVICE RTCinit MOVLW MOVWF CLRF MOVLW MOVWF CLRF CLRF MOVLW MOVWF BSF RETURN 80h TMR1H TMR1L b'00001111' T1CON secs mins .12 hours PIE1, TMR1IE BSF BCF INCF MOVLW CPFSGT RETURN CLRF INCF MOVLW CPFSGT RETURN CLRF INCF MOVLW CPFSGT RETURN CLRF RETURN TMR1H, 7 PIR1, TMR1IF secs, F .59 secs ; Preload TMR1 register pair ; for 1 second overflow ; Configure for external clock, ; Asynchronous operation, external oscillator ; Initialize timekeeping registers ; ; Enable Timer1 interrupt RTCisr TABLE 12-2: Name INTCON secs mins, F .59 mins mins hours, F .23 hours ; ; ; ; Preload for 1 sec overflow Clear interrupt flag Increment seconds 60 seconds elapsed? ; ; ; ; No, done Clear seconds Increment minutes 60 minutes elapsed? ; ; ; ; No, done clear minutes Increment hours 24 hours elapsed? ; No, done ; Reset hours ; Done hours REGISTERS ASSOCIATED WITH TIMER1 AS A TIMER/COUNTER Bit 7 Bit 5 Bit 4 Bit 3 Bit 2 Bit 1 Bit 0 Reset Values on page TMR0IE INT0IE RBIE TMR0IF INT0IF RBIF 57 Bit 6 GIE/GIEH PEIE/GIEL PIR1 -- ADIF RC1IF TX1IF SSPIF -- TMR2IF TMR1IF 60 PIE1 -- ADIE RC1IE TX1IE SSPIE -- TMR2IE TMR1IE 60 -- ADIP RC1IP TX1IP SSPIP -- TMR2IP TMR1IP 60 IPR1 TMR1L Timer1 Register Low Byte TMR1H Timer1 Register High Byte T1CON RD16 T1RUN T1CKPS1 T1CKPS0 T1OSCEN T1SYNC 58 58 TMR1CS TMR1ON 58 Legend: Shaded cells are not used by the Timer1 module. 2010 Microchip Technology Inc. DS39770C-page 145 PIC18F85J90 FAMILY NOTES: DS39770C-page 146 2010 Microchip Technology Inc. PIC18F85J90 FAMILY 13.0 TIMER2 MODULE 13.1 Timer2 Operation * 8-bit Timer and Period registers (TMR2 and PR2, respectively) * Readable and writable (both registers) * Software programmable prescaler (1:1, 1:4 and 1:16) * Software programmable postscaler (1:1 through 1:16) * Interrupt on TMR2 to PR2 match * Optional use as the shift clock for the MSSP module In normal operation, TMR2 is incremented from 00h on each clock (FOSC/4). A 4-bit counter/prescaler on the clock input gives direct input, divide-by-4 and divide-by-16 prescale options. These are selected by the prescaler control bits, T2CKPS<1:0> (T2CON<1:0>). The value of TMR2 is compared to that of the Period register, PR2, on each clock cycle. When the two values match, the comparator generates a match signal as the timer output. This signal also resets the value of TMR2 to 00h on the next cycle and drives the output counter/postscaler (see Section 13.2 "Timer2 Interrupt"). The module is controlled through the T2CON register (Register 13-1) which enables or disables the timer and configures the prescaler and postscaler. Timer2 can be shut off by clearing control bit, TMR2ON (T2CON<2>), to minimize power consumption. The TMR2 and PR2 registers are both directly readable and writable. The TMR2 register is cleared on any device Reset, while the PR2 register initializes at FFh. Both the prescaler and postscaler counters are cleared on the following events: A simplified block diagram of the module is shown in Figure 13-1. * a write to the TMR2 register * a write to the T2CON register * any device Reset (Power-on Reset, MCLR Reset, Watchdog Timer Reset or Brown-out Reset) The Timer2 module incorporates the following features: TMR2 is not cleared when T2CON is written. REGISTER 13-1: T2CON: TIMER2 CONTROL REGISTER U-0 R/W-0 R/W-0 R/W-0 R/W-0 R/W-0 R/W-0 R/W-0 -- T2OUTPS3 T2OUTPS2 T2OUTPS1 T2OUTPS0 TMR2ON T2CKPS1 T2CKPS0 bit 7 bit 0 Legend: R = Readable bit W = Writable bit U = Unimplemented bit, read as `0' -n = Value at POR `1' = Bit is set `0' = Bit is cleared bit 7 Unimplemented: Read as `0' bit 6-3 T2OUTPS<3:0>: Timer2 Output Postscale Select bits 0000 = 1:1 Postscale 0001 = 1:2 Postscale * * * 1111 = 1:16 Postscale bit 2 TMR2ON: Timer2 On bit 1 = Timer2 is on 0 = Timer2 is off bit 1-0 T2CKPS<1:0>: Timer2 Clock Prescale Select bits 00 = Prescaler is 1 01 = Prescaler is 4 1x = Prescaler is 16 2010 Microchip Technology Inc. x = Bit is unknown DS39770C-page 147 PIC18F85J90 FAMILY 13.2 Timer2 Interrupt 13.3 Timer2 can also generate an optional device interrupt. The Timer2 output signal (TMR2 to PR2 match) provides the input for the 4-bit output counter/postscaler. This counter generates the TMR2 match interrupt flag which is latched in TMR2IF (PIR1<1>). The interrupt is enabled by setting the TMR2 Match Interrupt Enable bit, TMR2IE (PIE1<1>). Timer2 Output The unscaled output of TMR2 is available primarily to the CCP modules, where it is used as a time base for operations in PWM mode. Timer2 can be optionally used as the shift clock source for the MSSP module operating in SPI mode. Additional information is provided in Section 17.0 "Master Synchronous Serial Port (MSSP) Module". A range of 16 postscale options (from 1:1 through 1:16 inclusive) can be selected with the postscaler control bits, T2OUTPS<3:0> (T2CON<6:3>). FIGURE 13-1: TIMER2 BLOCK DIAGRAM 4 T2OUTPS<3:0> T2CKPS<1:0> TMR2 Comparator PR2 8 8 Internal Data Bus Name TMR2 Output (to PWM or MSSP) TMR2/PR2 Match Reset 8 TABLE 13-1: Set TMR2IF 2 1:1, 1:4, 1:16 Prescaler FOSC/4 1:1 to 1:16 Postscaler REGISTERS ASSOCIATED WITH TIMER2 AS A TIMER/COUNTER Bit 7 Bit 6 INTCON GIE/GIEH PEIE/GIEL Bit 5 Bit 4 Bit 3 Bit 2 Bit 1 Bit 0 Reset Values on page 57 TMR0IE INT0IE RBIE TMR0IF INT0IF RBIF PIR1 -- ADIF RC1IF TX1IF SSPIF -- TMR2IF TMR1IF 60 PIE1 -- ADIE RC1IE TX1IE SSPIE -- TMR2IE TMR1IE 60 IPR1 -- ADIP RC1IP TX1IP SSPIP -- TMR2IP TMR1IP 60 TMR2 T2CON PR2 Timer2 Register -- T2OUTPS3 T2OUTPS2 T2OUTPS1 T2OUTPS0 TMR2ON 58 T2CKPS1 T2CKPS0 Timer2 Period Register 58 58 Legend: -- = unimplemented, read as `0'. Shaded cells are not used by the Timer2 module. DS39770C-page 148 2010 Microchip Technology Inc. PIC18F85J90 FAMILY 14.0 TIMER3 MODULE The Timer3 timer/counter module incorporates these features: * Software selectable operation as a 16-bit timer or counter * Readable and writable 8-bit registers (TMR3H and TMR3L) * Selectable clock source (internal or external) with device clock or Timer1 oscillator internal options * Interrupt on overflow * Module Reset on CCP Special Event Trigger REGISTER 14-1: A simplified block diagram of the Timer3 module is shown in Figure 14-1. A block diagram of the module's operation in Read/Write mode is shown in Figure 14-2. The Timer3 module is controlled through the T3CON register (Register 14-1). It also selects the clock source options for the CCP modules. See Section 15.2.2 "Timer1/Timer3 Mode Selection" for more information. T3CON: TIMER3 CONTROL REGISTER R/W-0 R/W-0 R/W-0 R/W-0 R/W-0 R/W-0 R/W-0 R/W-0 RD16 T3CCP2 T3CKPS1 T3CKPS0 T3CCP1 T3SYNC TMR3CS TMR3ON bit 7 bit 0 Legend: R = Readable bit W = Writable bit U = Unimplemented bit, read as `0' -n = Value at POR `1' = Bit is set `0' = Bit is cleared x = Bit is unknown bit 7 RD16: 16-Bit Read/Write Mode Enable bit 1 = Enables register read/write of Timer3 in one 16-bit operation 0 = Enables register read/write of Timer3 in two 8-bit operations bit 6,3 T3CCP<2:1>: Timer3 and Timer1 to CCPx Enable bits 1x = Timer3 is the capture/compare clock source for the CCP modules 01 = Timer3 is the capture/compare clock source for CCP2; Timer1 is the capture/compare clock source for CCP1 00 = Timer1 is the capture/compare clock source for the CCP modules bit 5-4 T3CKPS<1:0>: Timer3 Input Clock Prescale Select bits 11 = 1:8 Prescale value 10 = 1:4 Prescale value 01 = 1:2 Prescale value 00 = 1:1 Prescale value bit 2 T3SYNC: Timer3 External Clock Input Synchronization Control bit (Not usable if the device clock comes from Timer1/Timer3.) When TMR3CS = 1: 1 = Do not synchronize external clock input 0 = Synchronize external clock input When TMR3CS = 0: This bit is ignored. Timer3 uses the internal clock when TMR3CS = 0. bit 1 TMR3CS: Timer3 Clock Source Select bit 1 = External clock input from Timer1 oscillator or T13CKI (on the rising edge after the first falling edge) 0 = Internal clock (FOSC/4) bit 0 TMR3ON: Timer3 On bit 1 = Enables Timer3 0 = Stops Timer3 2010 Microchip Technology Inc. DS39770C-page 149 PIC18F85J90 FAMILY 14.1 Timer3 Operation The operating mode is determined by the clock select bit, TMR3CS (T3CON<1>). When TMR3CS is cleared (= 0), Timer3 increments on every internal instruction cycle (FOSC/4). When the bit is set, Timer3 increments on every rising edge of the Timer1 external clock input or the Timer1 oscillator, if enabled. Timer3 can operate in one of three modes: * Timer * Synchronous Counter * Asynchronous Counter FIGURE 14-1: As with Timer1, the RC1/T1OSI and RC0/T1OSO/T13CKI pins become inputs when the Timer1 oscillator is enabled. This means the values of TRISC<1:0> are ignored and the pins are read as `0'. TIMER3 BLOCK DIAGRAM (8-BIT MODE) Timer1 Oscillator Timer1 Clock Input 1 T1OSO/T13CKI 1 FOSC/4 Internal Clock T1OSI Synchronize Prescaler 1, 2, 4, 8 0 2 T1OSCEN(1) 0 Detect Sleep Input TMR3CS Timer3 On/Off T3CKPS<1:0> T3SYNC TMR3ON CCPx Special Event Trigger CCPx Select from T3CON<6,3> Clear TMR3 Set TMR3IF on Overflow TMR3 High Byte TMR3L Note 1: When enable bit, T1OSCEN, is cleared, the inverter and feedback resistor are turned off to eliminate power drain. FIGURE 14-2: TIMER3 BLOCK DIAGRAM (16-BIT READ/WRITE MODE) Timer1 Oscillator Timer1 Clock Input 1 T13CKI/T1OSO 1 FOSC/4 Internal Clock T1OSI Synchronize Prescaler 1, 2, 4, 8 2 T1OSCEN(1) 0 Detect 0 Sleep Input TMR3CS Timer3 On/Off T3CKPS<1:0> T3SYNC TMR3ON CCPx Special Event Trigger CCPx Select from T3CON<6,3> Clear TMR3 Set TMR3IF on Overflow TMR3 High Byte TMR3L 8 Read TMR3L Write TMR3L 8 8 TMR3H 8 8 Internal Data Bus Note 1: When enable bit, T1OSCEN, is cleared, the inverter and feedback resistor are turned off to eliminate power drain. DS39770C-page 150 2010 Microchip Technology Inc. PIC18F85J90 FAMILY 14.2 Timer3 16-Bit Read/Write Mode 14.4 Timer3 Interrupt Timer3 can be configured for 16-bit reads and writes (see Figure 14-2). When the RD16 control bit (T3CON<7>) is set, the address for TMR3H is mapped to a buffer register for the high byte of Timer3. A read from TMR3L will load the contents of the high byte of Timer3 into the Timer3 High Byte Buffer register. This provides the user with the ability to accurately read all 16 bits of Timer1 without having to determine whether a read of the high byte, followed by a read of the low byte, has become invalid due to a rollover between reads. The TMR3 register pair (TMR3H:TMR3L) increments from 0000h to FFFFh and overflows to 0000h. The Timer3 interrupt, if enabled, is generated on overflow and is latched in interrupt flag bit, TMR3IF (PIR2<1>). This interrupt can be enabled or disabled by setting or clearing the Timer3 Interrupt Enable bit, TMR3IE (PIE2<1>). A write to the high byte of Timer3 must also take place through the TMR3H Buffer register. The Timer3 high byte is updated with the contents of TMR3H when a write occurs to TMR3L. This allows a user to write all 16 bits to both the high and low bytes of Timer3 at once. If CCP1 or CCP2 is configured to use Timer3 and to generate a Special Event Trigger in Compare mode (CCPxM<3:0> = 1011), this signal will reset Timer3. The trigger from CCP2 will also start an A/D conversion if the A/D module is enabled (see Section 15.3.4 "Special Event Trigger" for more information). The high byte of Timer3 is not directly readable or writable in this mode. All reads and writes must take place through the Timer3 High Byte Buffer register. Writes to TMR3H do not clear the Timer3 prescaler. The prescaler is only cleared on writes to TMR3L. 14.3 Using the Timer1 Oscillator as the Timer3 Clock Source The Timer1 internal oscillator may be used as the clock source for Timer3. The Timer1 oscillator is enabled by setting the T1OSCEN (T1CON<3>) bit. To use it as the Timer3 clock source, the TMR3CS bit must also be set. As previously noted, this also configures Timer3 to increment on every rising edge of the oscillator source. 14.5 Resetting Timer3 Using the CCP Special Event Trigger The module must be configured as either a timer or synchronous counter to take advantage of this feature. When used this way, the CCPRxH:CCPRxL register pair effectively becomes a period register for Timer3. If Timer3 is running in Asynchronous Counter mode, the Reset operation may not work. In the event that a write to Timer3 coincides with a Special Event Trigger from a CCP module, the write will take precedence. Note: The Special Event Triggers from the CCPx module will not set the TMR3IF interrupt flag bit (PIR2<1>). The Timer1 oscillator is described in Section 12.0 "Timer1 Module". TABLE 14-1: Name INTCON REGISTERS ASSOCIATED WITH TIMER3 AS A TIMER/COUNTER Bit 7 Bit 6 GIE/GIEH PEIE/GIEL Bit 5 Bit 4 Bit 3 Bit 2 Bit 1 Bit 0 Reset Values on page TMR0IE INT0IE RBIE TMR0IF INT0IF RBIF 57 PIR2 OSCFIF CMIF -- -- BCLIF LVDIF TMR3IF -- 60 PIE2 OSCFIE CMIE -- -- BCLIE LVDIE TMR3IE -- 60 IPR2 OSCFIP CMIP -- -- BCLIP LVDIP TMR3IP -- 60 TMR3L Timer3 Register Low Byte 59 TMR3H Timer3 Register High Byte 59 T1CON RD16 T1RUN T1CKPS1 T1CKPS0 T1OSCEN T1SYNC TMR1CS TMR1ON 58 T3CON RD16 T3CCP2 T3CKPS1 T3CKPS0 TMR3CS TMR3ON 59 T3CCP1 T3SYNC Legend: -- = unimplemented, read as `0'. Shaded cells are not used by the Timer3 module. 2010 Microchip Technology Inc. DS39770C-page 151 PIC18F85J90 FAMILY NOTES: DS39770C-page 152 2010 Microchip Technology Inc. PIC18F85J90 FAMILY 15.0 CAPTURE/COMPARE/PWM (CCP) MODULES PIC18F85J90 family devices have two CCP (Capture/Compare/PWM) modules, designated CCP1 and CCP2. Both modules implement standard Capture, Compare and Pulse-Width Modulation (PWM) modes. REGISTER 15-1: Each CCP module contains a 16-bit register which can operate as a 16-bit Capture register, a 16-bit Compare register or a PWM Master/Slave Duty Cycle register. For the sake of clarity, all CCP module operation in the following sections is described with respect to CCP2, but is equally applicable to CCP1. CCPxCON: CCPx CONTROL REGISTER (CCP1, CCP2 MODULES) U-0 U-0 R/W-0 R/W-0 R/W-0 R/W-0 R/W-0 R/W-0 -- -- DCxB1 DCxB0 CCPxM3 CCPxM2 CCPxM1 CCPxM0 bit 7 bit 0 Legend: R = Readable bit W = Writable bit U = Unimplemented bit, read as `0' -n = Value at POR `1' = Bit is set `0' = Bit is cleared x = Bit is unknown bit 7-6 Unimplemented: Read as `0' bit 5-4 DCxB<1:0>: PWM Duty Cycle bit 1 and bit 0 for CCPx Module Capture mode: Unused. Compare mode: Unused. PWM mode: These bits are the two Least Significant bits (bit 1 and bit 0) of the 10-bit PWM duty cycle. The eight Most Significant bits (DCx<9:2>) of the duty cycle are found in CCPRxL. bit 3-0 CCPxM<3:0>: CCPx Module Mode Select bits 0000 = Capture/Compare/PWM disabled (resets CCPx module) 0001 = Reserved 0010 = Compare mode, toggle output on match (CCPxIF bit is set) 0011 = Reserved 0100 = Capture mode, every falling edge 0101 = Capture mode, every rising edge 0110 = Capture mode, every 4th rising edge 0111 = Capture mode, every 16th rising edge 1000 = Compare mode: initialize CCPx pin low; on compare match, force CCPx pin high (CCPxIF bit is set) 1001 = Compare mode: initialize CCPx pin high; on compare match, force CCPx pin low (CCPxIF bit is set) 1010 = Compare mode: generate software interrupt on compare match (CCPxIF bit is set, CCPx pin reflects I/O state) 1011 = Compare mode: Special Event Trigger; reset timer; start A/D conversion on CCPx match (CCPxIF bit is set)(1) 11xx = PWM mode Note 1: CCPxM<3:0> = 1011 will only reset the timer and not start an A/D conversion on CCP1 match. 2010 Microchip Technology Inc. DS39770C-page 153 PIC18F85J90 FAMILY 15.1 CCP Module Configuration Depending on the configuration selected, up to four timers may be active at once, with modules in the same configuration (Capture/Compare or PWM) sharing timer resources. The possible configurations are shown in Figure 15-1. Each Capture/Compare/PWM module is associated with a control register (generically, CCPxCON) and a data register (CCPRx). The data register in turn is comprised of two 8-bit registers: CCPRxL (low byte) and CCPRxH (high byte). All registers are both readable and writable. 15.1.1 15.1.2 When operating in Output mode (i.e., in Compare or PWM modes), the drivers for the CCPx pins can be optionally configured as open-drain outputs. This feature allows the voltage level on the pin to be pulled to a higher level through an external pull-up resistor and allows the output to communicate with external circuits without the need for additional level shifters. CCP MODULES AND TIMER RESOURCES The CCP modules utilize Timers 1, 2 or 3, depending on the mode selected. Timer1 and Timer3 are available to modules in Capture or Compare modes, while Timer2 is available for modules in PWM mode. TABLE 15-1: The open-drain output option is controlled by the CCP2OD and CCP1OD bits (TRISG<6:5>). Setting the appropriate bit configures the pin for the corresponding module for open-drain operation. CCP MODE - TIMER RESOURCE CCP Mode Timer Resource Capture Compare PWM Timer1 or Timer3 Timer1 or Timer3 Timer2 15.1.3 CCP2 PIN ASSIGNMENT The pin assignment for CCP2 (Capture input, Compare and PWM output) can change, based on device configuration. The CCP2MX Configuration bit determines which pin CCP2 is multiplexed to. By default, it is assigned to RC1 (CCP2MX = 1). If the Configuration bit is cleared, CCP2 is multiplexed with RE7. The assignment of a particular timer to a module is determined by the Timer to CCP enable bits in the T3CON register (Register 14-1). Both modules may be active at any given time and may share the same timer resource if they are configured to operate in the same mode (Capture/Compare or PWM) at the same time. The interactions between the two modules are summarized in Table 15-2. FIGURE 15-1: OPEN-DRAIN OUTPUT OPTION Changing the pin assignment of CCP2 does not automatically change any requirements for configuring the port pin. Users must always verify that the appropriate TRIS register is configured correctly for CCP2 operation, regardless of where it is located. CCP AND TIMER INTERCONNECT CONFIGURATIONS T3CCP<2:1> = 00 T3CCP<2:1> = 01 TMR1 TMR1 TMR3 CCP1 TMR3 CCP1 Timer1 is used for all Capture and Compare operations for all CCP modules. Timer2 is used for PWM operations for all CCP modules. Modules may share either timer resource as a common time base. DS39770C-page 154 TMR1 TMR3 CCP1 CCP2 TMR2 T3CCP<2:1> = 1x CCP2 TMR2 Timer1 is used for Capture and Compare operations for CCP1 and Timer 3 is used for CCP2. Both the modules use Timer2 as a common time base if they are in PWM modes. CCP2 TMR2 Timer3 is used for all Capture and Compare operations for all CCP modules. Timer2 is used for PWM operations for all CCP modules. Modules may share either timer resource as a common time base. 2010 Microchip Technology Inc. PIC18F85J90 FAMILY TABLE 15-2: INTERACTIONS BETWEEN CCP1 AND CCP2 FOR TIMER RESOURCES CCP1 Mode CCP2 Mode Interaction Capture Capture Each module can use TMR1 or TMR3 as the time base. The time base can be different for each CCP. Capture Compare CCP2 can be configured for the Special Event Trigger to reset TMR1 or TMR3 (depending upon which time base is used). Automatic A/D conversions on a trigger event can also be done. Operation of CCP1 could be affected if it is using the same timer as a time base. Compare Capture CCP1 can be configured for the Special Event Trigger to reset TMR1 or TMR3 (depending upon which time base is used). Operation of CCP2 could be affected if it is using the same timer as a time base. Compare Compare Either module can be configured for the Special Event Trigger to reset the time base. Automatic A/D conversions on CCP2 trigger event can be done. Conflicts may occur if both modules are using the same time base. Capture PWM None Compare PWM None PWM Capture None PWM Compare None PWM PWM Both PWMs will have the same frequency and update rate (TMR2 interrupt). 2010 Microchip Technology Inc. DS39770C-page 155 PIC18F85J90 FAMILY 15.2 Capture Mode 15.2.3 SOFTWARE INTERRUPT In Capture mode, the CCPR2H:CCPR2L register pair captures the 16-bit value of the TMR1 or TMR3 register when an event occurs on the CCP2 pin (RC1 or RE7, depending on device configuration). An event is defined as one of the following: When the Capture mode is changed, a false capture interrupt may be generated. The user should keep the CCP2IE bit (PIE3<2>) clear to avoid false interrupts and should clear the flag bit, CCP2IF, following any such change in operating mode. * * * * 15.2.4 every falling edge every rising edge every 4th rising edge every 16th rising edge There are four prescaler settings in Capture mode. They are specified as part of the operating mode selected by the mode select bits (CCP2M<3:0>). Whenever the CCP module is turned off, or the CCP module is not in Capture mode, the prescaler counter is cleared. This means that any Reset will clear the prescaler counter. The event is selected by the mode select bits, CCP2M<3:0> (CCP2CON<3:0>). When a capture is made, the interrupt request flag bit, CCP2IF (PIR3<2>), is set; it must be cleared in software. If another capture occurs before the value in register, CCPR2, is read, the old captured value is overwritten by the new captured value. 15.2.1 Switching from one capture prescaler to another may generate an interrupt. Also, the prescaler counter will not be cleared; therefore, the first capture may be from a non-zero prescaler. Example 15-1 shows the recommended method for switching between capture prescalers. This example also clears the prescaler counter and will not generate the "false" interrupt. CCP PIN CONFIGURATION In Capture mode, the appropriate CCPx pin should be configured as an input by setting the corresponding TRIS direction bit. Note: 15.2.2 EXAMPLE 15-1: If RC1/CCP2 or RE7/CCP2 is configured as an output, a write to the port can cause a capture condition. CHANGING BETWEEN CAPTURE PRESCALERS CLRF CCP2CON ; Turn CCP module off MOVLW NEW_CAPT_PS ; Load WREG with the ; new prescaler mode ; value and CCP ON MOVWF CCP2CON ; Load CCP2CON with ; this value TIMER1/TIMER3 MODE SELECTION The timers that are to be used with the capture feature (Timer1 and/or Timer3) must be running in Timer mode or Synchronized Counter mode. In Asynchronous Counter mode, the capture operation may not work. The timer to be used with each CCP module is selected in the T3CON register (see Section 15.1.1 "CCP Modules and Timer Resources"). FIGURE 15-2: CCP PRESCALER CAPTURE MODE OPERATION BLOCK DIAGRAM TMR3H Set CCP1IF T3CCP2 CCP1 Pin Prescaler 1, 4, 16 and Edge Detect CCP1CON<3:0> Q1:Q4 CCP2CON<3:0> 4 4 CCPR1L TMR1 Enable TMR1H TMR1L TMR3H TMR3L Set CCP2IF 4 T3CCP1 T3CCP2 CCP2 Pin Prescaler 1, 4, 16 TMR3 Enable CCPR1H T3CCP2 TMR3L and Edge Detect TMR3 Enable CCPR2H CCPR2L TMR1 Enable T3CCP2 T3CCP1 DS39770C-page 156 TMR1H TMR1L 2010 Microchip Technology Inc. PIC18F85J90 FAMILY 15.3 Compare Mode 15.3.3 SOFTWARE INTERRUPT MODE In Compare mode, the 16-bit CCPR2 register value is constantly compared against either the TMR1 or TMR3 register pair value. When a match occurs, the CCP2 pin can be: When the Generate Software Interrupt mode is chosen (CCP2M<3:0> = 1010), the CCP2 pin is not affected. Only a CCP interrupt is generated, if enabled, and the CCP2IE bit is set. * * * * 15.3.4 driven high driven low toggled (high-to-low or low-to-high) remain unchanged (that is, reflects the state of the I/O latch) Both CCP modules are equipped with a Special Event Trigger. This is an internal hardware signal generated in Compare mode to trigger actions by other modules. The Special Event Trigger is enabled by selecting the Compare Special Event Trigger mode (CCP2M<3:0> = 1011). The action on the pin is based on the value of the mode select bits (CCP2M<3:0>). At the same time, the interrupt flag bit, CCP2IF, is set. 15.3.1 For either CCP module, the Special Event Trigger resets the timer register pair for whichever timer resource is currently assigned as the module's time base. This allows the CCPRx registers to serve as a programmable period register for either timer. CCP PIN CONFIGURATION The user must configure the CCPx pin as an output by clearing the appropriate TRIS bit. Note: 15.3.2 SPECIAL EVENT TRIGGER The Special Event Trigger for CCP2 can also start an A/D conversion. In order to do this, the A/D Converter must already be enabled. Clearing the CCP2CON register will force the RC1 or RE7 compare output latch (depending on device configuration) to the default low level. This is not the PORTC or PORTE I/O data latch. Note: TIMER1/TIMER3 MODE SELECTION The Special Event Trigger of CCP1 only resets Timer1/Timer3 and cannot start an A/D conversion even when the A/D Converter is enabled. Timer1 and/or Timer3 must be running in Timer mode, or Synchronized Counter mode, if the CCP module is using the compare feature. In Asynchronous Counter mode, the compare operation may not work. FIGURE 15-3: COMPARE MODE OPERATION BLOCK DIAGRAM CCPR1H Special Event Trigger (Timer1 Reset) Set CCP1IF CCPR1L CCP1 Pin Comparator Output Logic Compare Match S Q R TRIS Output Enable 4 CCP1CON<3:0> 0 TMR1H TMR1L 0 1 TMR3H TMR3L 1 T3CCP1 Special Event Trigger (Timer1/Timer3 Reset, A/D Trigger) T3CCP2 Set CCP2IF Comparator CCPR2H CCPR2L Compare Match CCP2 Pin Output Logic 4 S Q R TRIS Output Enable CCP2CON<3:0> 2010 Microchip Technology Inc. DS39770C-page 157 PIC18F85J90 FAMILY TABLE 15-3: Name INTCON REGISTERS ASSOCIATED WITH CAPTURE, COMPARE, TIMER1 AND TIMER3 Bit 7 Bit 6 Bit 5 GIE/GIEH PEIE/GIEL TMR0IE Bit 4 Bit 3 Bit 2 Bit 1 Bit 0 Reset Values on Page INT0IE RBIE TMR0IF INT0IF RBIF 57 IPEN -- CM RI TO PD POR BOR 58 PIR3 -- LCDIF RC2IF TX2IF -- CCP2IF CCP1IF -- 60 PIE3 -- LCDIE RC2IE TX2IE -- CCP2IE CCP1IE -- 60 IPR3 -- LCDIP RC2IP TX2IP -- CCP2IP CCP1IP -- 60 RCON PIR2 OSCFIF CMIF -- -- BCLIF LVDIF TMR3IF -- 60 PIE2 OSCFIE CMIE -- -- BCLIE LVDIE TMR3IE -- 60 IPR2 OSCFIP CMIP -- -- BCLIP LVDIP TMR3IP -- 60 TRISC TRISC7 TRISC6 TRISC5 TRISC4 TRISC3 TRISC2 TRISC1 TRISC0 60 TRISE TRISE7 TRISE6 TRISE5 TRISG SPIOD CCP2OD CCP1OD TRISE4 TRISE3 -- TRISE1 TRISE0 60 TRISG4 TRISG3 TRISG2 TRISG1 TRISG0 60 TMR1L Timer1 Register Low Byte 58 TMR1H Timer1 Register High Byte 58 T1CON RD16 T1RUN T1CKPS1 T1CKPS0 T1OSCEN T1SYNC TMR1CS TMR1ON 58 TMR3H Timer3 Register High Byte 59 TMR3L Timer3 Register Low Byte 59 T3CON RD16 T3CCP2 T3CKPS1 T3CKPS0 CCPR1L Capture/Compare/PWM Register 1 Low Byte CCPR1H Capture/Compare/PWM Register 1 High Byte -- CCP1CON -- DC1B1 DC1B0 T3CCP1 T3SYNC TMR3CS TMR3ON 59 61 61 CCP1M3 CCP1M2 CCP1M1 CCP1M0 61 CCPR2L Capture/Compare/PWM Register 2 Low Byte 62 CCPR2H Capture/Compare/PWM Register 2 High Byte 61 CCP2CON -- -- DC2B1 DC2B0 CCP2M3 CCP2M2 CCP2M1 CCP2M0 62 Legend: -- = unimplemented, read as `0'. Shaded cells are not used by Capture/Compare, Timer1 or Timer3. DS39770C-page 158 2010 Microchip Technology Inc. PIC18F85J90 FAMILY 15.4 PWM Mode In Pulse-Width Modulation (PWM) mode, the CCP2 pin produces up to a 10-bit resolution PWM output. Since the CCP2 pin is multiplexed with a PORTC or PORTE data latch, the appropriate TRIS bit must be cleared to make the CCP2 pin an output. Note: A PWM output (Figure 15-5) has a time base (period) and a time that the output stays high (duty cycle). The frequency of the PWM is the inverse of the period (1/period). FIGURE 15-5: PWM OUTPUT Period Clearing the CCP2CON register will force the RC1 or RE7 output latch (depending on device configuration) to the default low level. This is not the PORTC or PORTE I/O data latch. Duty Cycle TMR2 = PR2 Figure 15-4 shows a simplified block diagram of the CCP1 module in PWM mode. For a step-by-step procedure on how to set up the CCP module for PWM operation, see Section 15.4.3 "Setup for PWM Operation". FIGURE 15-4: SIMPLIFIED PWM BLOCK DIAGRAM Duty Cycle Registers TMR2 = Duty Cycle TMR2 = PR2 15.4.1 PWM PERIOD The PWM period is specified by writing to the PR2 register. The PWM period can be calculated using the following formula: CCP1CON<5:4> EQUATION 15-1: CCPR1L PWM Period = (PR2) + 1] * 4 * TOSC * (TMR2 Prescale Value) PWM frequency is defined as 1/[PWM period]. CCPR1H (Slave) R Comparator When TMR2 is equal to PR2, the following three events occur on the next increment cycle: Q RC2/CCP1 TMR2 Comparator PR2 Note 1: (Note 1) S TRISC<2> Clear Timer, CCP1 pin and latch D.C. The 8-bit TMR2 value is concatenated with the 2-bit internal Q clock, or 2 bits of the prescaler, to create the 10-bit time base. 2010 Microchip Technology Inc. * TMR2 is cleared * The CCP2 pin is set (exception: if PWM duty cycle = 0%, the CCP2 pin will not be set) * The PWM duty cycle is latched from CCPR2L into CCPR2H Note: The Timer2 postscalers (see Section 13.0 "Timer2 Module") are not used in the determination of the PWM frequency. The postscaler could be used to have a servo update rate at a different frequency than the PWM output. DS39770C-page 159 PIC18F85J90 FAMILY 15.4.2 PWM DUTY CYCLE The PWM duty cycle is specified by writing to the CCPR2L register and to the CCP2CON<5:4> bits. Up to 10-bit resolution is available. The CCPR2L contains the eight MSbs and the CCP2CON<5:4> contains the two LSbs. This 10-bit value is represented by CCPR2L:CCP2CON<5:4>. The following equation is used to calculate the PWM duty cycle in time: EQUATION 15-2: When the CCPR2H and 2-bit latch match TMR2, concatenated with an internal 2-bit Q clock or 2 bits of the TMR2 prescaler, the CCP2 pin is cleared. The maximum PWM resolution (bits) for a given PWM frequency is given by the equation: EQUATION 15-3: PWM Duty Cycle = (CCPR2L:CCP2CON<5:4>) * TOSC * (TMR2 Prescale Value) CCPR2L and CCP2CON<5:4> can be written to at any time, but the duty cycle value is not latched into CCPR2H until after a match between PR2 and TMR2 occurs (i.e., the period is complete). In PWM mode, CCPR2H is a read-only register. TABLE 15-4: The CCPR2H register and a 2-bit internal latch are used to double-buffer the PWM duty cycle. This double-buffering is essential for glitchless PWM operation. F OSC log --------------- F PWM PWM Resolution (max) = -----------------------------bits log 2 Note: If the PWM duty cycle value is longer than the PWM period, the CCP2 pin will not be cleared. EXAMPLE PWM FREQUENCIES AND RESOLUTIONS AT 40 MHz PWM Frequency Timer Prescaler (1, 4, 16) PR2 Value Maximum Resolution (bits) DS39770C-page 160 2.44 kHz 9.77 kHz 39.06 kHz 156.25 kHz 312.50 kHz 416.67 kHz 16 4 1 1 1 1 FFh FFh FFh 3Fh 1Fh 17h 14 12 10 8 7 6.58 2010 Microchip Technology Inc. PIC18F85J90 FAMILY 15.4.3 SETUP FOR PWM OPERATION 3. The following steps should be taken when configuring the CCP module for PWM operation: 1. 2. Set the PWM period by writing to the PR2 register. Set the PWM duty cycle by writing to the CCPR2L register and CCP2CON<5:4> bits. TABLE 15-5: Name INTCON 4. 5. Make the CCP2 pin an output by clearing the appropriate TRIS bit. Set the TMR2 prescale value, then enable Timer2 by writing to T2CON. Configure the CCP2 module for PWM operation. REGISTERS ASSOCIATED WITH PWM AND TIMER2 Bit 7 Bit 6 GIE/GIEH PEIE/GIEL Bit 5 Bit 4 Bit 3 Bit 2 Bit 1 Bit 0 Reset Values on Page TMR0IE INT0IE RBIE TMR0IF INT0IF RBIF 57 CM RI TO PD POR BOR 58 IPEN -- PIR1 -- ADIF RC1IF TX1IF SSPIF -- TMR2IF TMR1IF 60 PIE1 -- ADIE RC1IE TX1IE SSPIE -- TMR2IE TMR1IE 60 IPR1 -- ADIP RC1IP TX1IP SSPIP -- TMR2IP TMR1IP 60 TRISC TRISC7 TRISC6 TRISC5 TRISC4 TRISC3 TRISC2 TRISC1 TRISC0 60 TRISE TRISE7 TRISE6 TRISE5 TRISE4 TRISE3 -- TRISE1 TRISE0 60 TRISG SPIOD CCP2OD CCP1OD TRISG4 TRISG3 TRISG2 TRISG1 TRISG0 60 RCON TMR2 Timer2 Register PR2 Timer2 Period Register T2CON -- 58 58 T2OUTPS3 T2OUTPS2 T2OUTPS1 T2OUTPS0 TMR2ON T2CKPS1 T2CKPS0 58 CCPR1L Capture/Compare/PWM Register 1 Low Byte 61 CCPR1H Capture/Compare/PWM Register 1 High Byte 61 CCP1CON -- -- DC1B1 DC1B0 CCPR2L Capture/Compare/PWM Register 2 Low Byte CCPR2H Capture/Compare/PWM Register 2 High Byte CCP2CON -- -- DC2B1 DC2B0 CCP1M3 CCP1M2 CCP1M1 CCP1M0 61 62 61 CCP2M3 CCP2M2 CCP2M1 CCP2M0 62 Legend: -- = unimplemented, read as `0'. Shaded cells are not used by PWM or Timer2. 2010 Microchip Technology Inc. DS39770C-page 161 PIC18F85J90 FAMILY NOTES: DS39770C-page 162 2010 Microchip Technology Inc. PIC18F85J90 FAMILY 16.0 LIQUID CRYSTAL DISPLAY (LCD) DRIVER MODULE The LCD driver module supports these features: * Direct driving of LCD panel * On-chip bias generator with dedicated charge pump to support a range of fixed and variable bias options * Up to four commons, with four Multiplexing modes * Up to 48 (80-pin devices) or 33 (64-pin devices) segments * Three LCD clock sources with selectable prescaler, with a fourth source available for use with the LCD charge pump The Liquid Crystal Display (LCD) driver module generates the timing control to drive a static or multiplexed LCD panel. It also provides control of the LCD pixel data. The module can drive panels of up to 192 pixels (48 segments by 4 commons) in 80-pin devices, and 132 pixels (33 segments by 4 commons) in 64-pin devices. A simplified block diagram of the module is shown in Figure 16-1. FIGURE 16-1: LCD DRIVER MODULE BLOCK DIAGRAM Data Bus LCD DATA 24 x 8 (= 4 x 48) 8 LCDDATA23 192 LCDDATA22 . . . LCDDATA1 to 48 48 SEG<47:0> MUX LCDDATA0 Bias Voltage To I/O Pins Timing Control LCDCON 4 LCDPS LCDSEx COM3:COM0 LCD Bias Generation FOSC/4 T13CKI INTRC Oscillator INTOSC Oscillator 2010 Microchip Technology Inc. LCD Clock Source Select LCD Charge Pump DS39770C-page 163 PIC18F85J90 FAMILY 16.1 LCD Registers The LCDPS register, shown in Register 16-2, configures the LCD clock source prescaler and the type of waveform: Type-A or Type-B. Details on these features are provided in Section 16.2 "LCD Clock Source", Section 16.3 "LCD Bias Generation" and Section 16.8 "LCD Waveform Generation". The LCD driver module has 33 registers: * * * * LCD Control Register (LCDCON) LCD Phase Register (LCDPS) LCD Regulator Control Register (LCDREG) Six LCD Segment Enable Registers (LCDSE5:LCDSE0) * 24 LCD Data Registers (LCDDATA23:LCDDATA0) 16.1.1 The LCDREG register is described in Section 16.3 "LCD Bias Generation". LCD CONTROL REGISTERS The LCDCON register, shown in Register 16-1, controls the overall operation of the module. Once the module is configured, the LCDEN (LCDCON<7>) bit is used to enable or disable the LCD module. The LCD panel can also operate during Sleep by clearing the SLPEN (LCDCON<6>) bit. REGISTER 16-1: The LCD Segment Enable registers (LCDSEx) configure the functions of the port pins. Setting the segment enable bit for a particular segment configures that pin as an LCD driver. The prototype LCDSE register is shown in Register 16-3. There are six LCDSE registers (LCDSE5:LCDSE0) listed in Table 16-1. LCDCON: LCD CONTROL REGISTER R/W-0 R/W-0 R/C-0 U-0 R/W-0 R/W-0 R/W-0 R/W-0 LCDEN SLPEN WERR -- CS1 CS0 LMUX1 LMUX0 bit 7 bit 0 Legend: C = Clearable bit R = Readable bit W = Writable bit U = Unimplemented bit, read as `0' -n = Value at POR `1' = Bit is set `0' = Bit is cleared x = Bit is unknown bit 7 LCDEN: LCD Driver Enable bit 1 = LCD driver module is enabled 0 = LCD driver module is disabled bit 6 SLPEN: LCD Driver Enable in Sleep mode bit 1 = LCD driver module is disabled in Sleep mode 0 = LCD driver module is enabled in Sleep mode bit 5 WERR: LCD Write Failed Error bit 1 = LCDDATAx register written while LCDPS<4> = 0 (must be cleared in software) 0 = No LCD write error bit 4 Unimplemented: Read as `0' bit 3-2 CS<1:0>: Clock Source Select bits 1x = INTRC (31 kHz) 01 = T13CKI (Timer1) 00 = System clock (FOSC/4) bit 1-0 LMUX<1:0>: Commons Select bits LMUX<1:0> Multiplex Type 00 DS39770C-page 164 Maximum Number of Pixels: Bias Type PIC18F6XJ90 PIC18F8XJ90 Static (COM0) 33 48 Static 01 1/2 (COM1:COM0) 66 96 1/2 or 1/3 10 1/3 (COM2:COM0) 99 144 1/2 or 1/3 11 1/4 (COM3:COM0) 132 192 1/3 2010 Microchip Technology Inc. PIC18F85J90 FAMILY REGISTER 16-2: LCDPS: LCD PHASE REGISTER R/W-0 R/W-0 R-0 R-0 R/W-0 R/W-0 R/W-0 R/W-0 WFT BIASMD LCDA WA LP3 LP2 LP1 LP0 bit 7 bit 0 Legend: R = Readable bit W = Writable bit U = Unimplemented bit, read as `0' -n = Value at POR `1' = Bit is set `0' = Bit is cleared bit 7 WFT: Waveform Type Select bit 1 = Type-B waveform (phase changes on each frame boundary) 0 = Type-A waveform (phase changes within each common type) bit 6 BIASMD: Bias Mode Select bit When LMUX<1:0> = 00: 0 = Static Bias mode (do not set this bit to `1') When LMUX<1:0> = 01 or 10: 1 = 1/2 Bias mode 0 = 1/3 Bias mode When LMUX<1:0> = 11: 0 = 1/3 Bias mode (do not set this bit to `1') bit 5 LCDA: LCD Active Status bit 1 = LCD driver module is active 0 = LCD driver module is inactive bit 4 WA: LCD Write Allow Status bit 1 = Write into the LCDDATAx registers is allowed 0 = Write into the LCDDATAx registers is not allowed bit 3-0 LP<3:0>: LCD Prescaler Select bits 1111 = 1:16 1110 = 1:15 1101 = 1:14 1100 = 1:13 1011 = 1:12 1010 = 1:11 1001 = 1:10 1000 = 1:9 0111 = 1:8 0110 = 1:7 0101 = 1:6 0100 = 1:5 0011 = 1:4 0010 = 1:3 0001 = 1:2 0000 = 1:1 2010 Microchip Technology Inc. x = Bit is unknown DS39770C-page 165 PIC18F85J90 FAMILY REGISTER 16-3: LCDSEx: LCD SEGMENT ENABLE REGISTERS R/W-0 R/W-0 R/W-0 R/W-0 R/W-0 R/W-0 R/W-0 R/W-0 SE(n + 7) SE(n + 6) SE(n + 5) SE(n + 4) SE(n + 3) SE(n + 2) SE(n + 1) SE(n) bit 7 bit 0 Legend: R = Readable bit W = Writable bit U = Unimplemented bit, read as `0' -n = Value at POR `1' = Bit is set `0' = Bit is cleared bit 7-0 SEG(n + 7):SEG(n): Segment Enable bits For LCDSE0: n = 0 For LCDSE1: n = 8 For LCDSE2: n = 16 For LCDSE3: n = 24 For LCDSE4: n = 32 For LCDSE5: n = 40 1 = Segment function of the pin is enabled, digital I/O disabled 0 = I/O function of the pin is enabled TABLE 16-1: LCDSE REGISTERS AND ASSOCIATED SEGMENTS Register Note 1: 2: x = Bit is unknown Segments LCDSE0 7:0 LCDSE1 15:8 LCDSE2 23:16 LCDSE3 31:24 (1) LCDSE4 39:32 LCDSE5(2) 47:40 LCDSE4<7:1> (SEG39:SEG33) are not implemented in 64-pin devices. LCDSE5 is not implemented in 64-pin devices. DS39770C-page 166 2010 Microchip Technology Inc. PIC18F85J90 FAMILY 16.1.2 LCD DATA REGISTERS Individual LCDDATA bits are named by the convention "SxxCy", with "xx" as the segment number and "y" as the common number. The relationship is summarized in Table 16-2. The prototype LCDDATA register is shown in Register 16-4. Once the module is initialized for the LCD panel, the individual bits of the LCDDATA23:LCDDATA0 registers are cleared or set to represent a clear or dark pixel, respectively. Specific sets of LCDDATA registers are used with specific segments and common signals. Each bit represents a unique combination of a specific segment connected to a specific common. REGISTER 16-4: Note: In 64-pin devices, writing into the registers LCDDATA5, LCDDATA11, LCDDATA17, and LCDDATA23 will not affect the status of any pixels. LCDDATAx: LCD DATA REGISTERS R/W-0 R/W-0 R/W-0 R/W-0 R/W-0 R/W-0 R/W-0 R/W-0 S(n + 7)Cy S(n + 6)Cy S(n + 5)Cy S(n + 4)Cy S(n + 3)Cy S(n + 2)Cy S(n + 1)Cy S(n)Cy bit 7 bit 0 Legend: R = Readable bit W = Writable bit U = Unimplemented bit, read as `0' -n = Value at POR `1' = Bit is set `0' = Bit is cleared bit 7-0 x = Bit is unknown S(n + 7)Cy:S(n)Cy: Pixel On bits For LCDDATA0 through LCDDATA5: n = (8x), y = 0 For LCDDATA6 through LCDDATA11: n = (8(x - 6)), y = 1 For LCDDATA12 through LCDDATA17: n = (8(x - 12)), y = 2 For LCDDATA18 through LCDDATA23: n = (8(x - 18)), y = 3 1 = Pixel on (dark) 0 = Pixel off (clear) TABLE 16-2: LCDDATA REGISTERS AND BITS FOR SEGMENT AND COM COMBINATIONS COM Lines Segments 0 through 7 8 through 15 16 through 23 24 through 31 32 through 39 40 through 47 Note 1: 2: 0 1 2 3 LCDDATA0 LCDDATA6 LCDDATA12 LCDDATA18 S00C0:S07C0 S00C1:S07C1 S00C2:S07C2 S00C3:S07C3 LCDDATA1 LCDDATA7 LCDDATA13 LCDDATA19 S08C0:S15C0 S08C1:S15C1 S08C2:S15C2 S08C0:S15C3 LCDDATA2 LCDDATA8 LCDDATA14 LCDDATA20 S16C0:S23C0 S16C1:S23C1 S16C2:S23C2 S16C3:S23C3 LCDDATA3 LCDDATA9 LCDDATA15 LCDDATA21 S24C0:S31C0 S24C1:S31C1 S24C2:S31C2 S24C3:S31C3 LCDDATA4(1) LCDDATA10(1) LCDDATA16(1) LCDDATA22(1) S32C0:S39C0 S32C1:S39C1 S32C2:S39C2 S32C3:S39C3 LCDDATA5(2) (2) LCDDATA11 LCDDATA17 (2) LCDDATA23(2) S40C0:S47C0 S40C1:S47C1 S40C2:S47C2 S40C3:S47C3 Bits<7:1> of these registers are not implemented in 64-pin devices. Bit 0 of these registers (SEG32Cy) is always implemented. These registers are not implemented on 64-pin devices. 2010 Microchip Technology Inc. DS39770C-page 167 PIC18F85J90 FAMILY 16.2 LCD Clock Source The charge pump clock can use either the Timer1 oscillator or the INTRC source, as well as the 8 MHz INTOSC source (after being divided by 256 by a prescaler). The charge pump clock source is configured using the CKSEL<1:0> bits (LCDREG<1:0>). The LCD driver module generates its internal clock from 3 possible sources: * System clock (FOSC/4) * Timer1 oscillator * INTRC source 16.2.2 The LCD clock generator uses a configurable divide-by-32/divide-by-8192 postscaler to produce a baseline frequency of about 1 kHz nominal, regardless of the source selected. The clock source selection and the postscaler configuration are determined by the Clock Source Select bits, CS<1:0> (LCDCON<3:2>). When using the system clock as the LCD clock source, it is assumed that the system clock frequency is a nominal 32 MHz (for a FOSC/4 frequency of 8 MHz). Because the prescaler option for the FOSC/4 clock selection is fixed at divide-by-8192, system clock speeds that differ from 32 MHz will produce frame frequencies and refresh rates different than discussed in this chapter. The user will need to keep this in mind when designing the display application. An additional programmable prescaler is used to derive the LCD frame frequency from the 1 kHz baseline. The prescaler is configured using the LP<3:0> bits (LCDPS<3:0>) for any one of 16 options, ranging from 1:1 to 1:16. The Timer1 and INTRC sources can be used as LCD clock sources when the device is in Sleep mode. To use the Timer1 oscillator, it is necessary to set the T1OSCEN bit (T1CON<3>). Selecting either Timer1 or INTRC as the LCD clock source will not automatically activate these sources. Proper timing for waveform generation is set by the LMUX<1:0> bits (LCDCON<1:0>). These bits determine which Commons Multiplexing mode is to be used, and divide down the LCD clock source as required. They also determine the configuration of the ring counter that is used to switch the LCD commons on or off. 16.2.1 Similarly, selecting the INTOSC as the charge pump clock source will not turn the oscillator on. To use INTOSC, it must be selected as the system clock source by using the FOSC2 Configuration bit. LCD VOLTAGE REGULATOR CLOCK SOURCE If Timer1 is used as a clock source for the device, either as an LCD clock source or for any other purpose, LCD segment 32 become unavailable. In addition to the clock source for LCD timing, a separate 31 kHz nominal clock is required for the LCD charge pump. This is provided from a distinct branch of the LCD clock source. FIGURE 16-2: CLOCK SOURCE CONSIDERATIONS LCD CLOCK GENERATION LCDCON<3:2> 2 System Clock (FOSC/4) 00 Timer1 Oscillator 01 Internal 31 kHz Source 1x /4 00 /2 01 LCDPS<3:0> 4 1:1 to 1:16 Programmable Prescaler 10 /32 or /8192 /1, 2, 3, 4 Ring Counter COM0 COM1 COM2 COM3 11 LCDCON<1:0> LCDREG<1:0> 2 2 11 INTOSC 8 MHz Source /256 10 31 kHz Clock to LCD Charge Pump 01 DS39770C-page 168 2010 Microchip Technology Inc. PIC18F85J90 FAMILY 16.3 LCD Bias Generation 16.3.2 LCD VOLTAGE REGULATOR The LCD driver module is capable of generating the required bias voltages for LCD operation with a minimum of external components. This includes the ability to generate the different voltage levels required by the different bias types required by the LCD. The driver module can also provide bias voltages both above and below microcontroller VDD through the use of an on-chip LCD voltage regulator. The purpose of the LCD regulator is to provide proper bias voltage and good contrast for the LCD, regardless of VDD levels. This module contains a charge pump and internal voltage reference. The regulator can be configured by using external components to boost bias voltage above VDD. It can also operate a display at a constant voltage below VDD. The regulator can also be selectively disabled to allow bias voltages to be generated by an external resistor network. 16.3.1 The LCD regulator is controlled through the LCDREG register (Register 16-5). It is enabled or disabled using the CKSEL<1:0> bits, while the charge pump can be selectively enabled using the CPEN bit. When the regulator is enabled, the MODE13 bit is used to select the bias type. The peak LCD bias voltage, measured as a difference between the potentials of LCDBIAS3 and LCDBIAS0, is configured with the BIAS bits. LCD BIAS TYPES PIC18F85J90 family devices support three bias types based on the waveforms generated to control segments and commons: * Static (two discrete levels) * 1/2 Bias (three discrete levels * 1/3 Bias (four discrete levels) The use of different waveforms in driving the LCD is discussed in more detail in Section 16.8 "LCD Waveform Generation". REGISTER 16-5: LCDREG: VOLTAGE REGULATOR CONTROL REGISTER U-0 RW-0 RW-1 RW-1 RW-1 RW-1 RW-0 RW-0 -- CPEN BIAS2 BIAS1 BIAS0 MODE13 CKSEL1 CKSEL0 bit 7 bit 0 Legend: R = Readable bit W = Writable bit U = Unimplemented bit, read as `0' -n = Value at POR `1' = Bit is set `0' = Bit is cleared bit 7 Unimplemented: Read as `0' bit 6 CPEN: LCD Charge Pump Enable bit 1 = Charge pump enabled; highest LCD bias voltage is 3.6V 0 = Charge pump disabled; highest LCD bias voltage is AVDD bit 5-3 BIAS<2:0>: Regulator Voltage Output Control bits 111 = 3.60V peak (offset on LCDBIAS0 of 0V) 110 = 3.47V peak (offset on LCDBIAS0 of 0.13V) 101 = 3.34V peak (offset on LCDBIAS0 of 0.26V) 100 = 3.21V peak (offset on LCDBIAS0 of 0.39V) 011 = 3.08V peak (offset on LCDBIAS0 of 0.52V) 010 = 2.95V peak (offset on LCDBIAS0 of 0.65V) 001 = 2.82V peak (offset on LCDBIAS0 of 0.78V) 000 = 2.69V peak (offset on LCDBIAS0 of 0.91V) bit 2 MODE13: 1/3 LCD Bias Enable bit 1 = Regulator output supports 1/3 LCD Bias mode 0 = Regulator output supports static LCD Bias mode bit 1-0 CKSEL<1:0>: Regulator Clock Source Select bits 11 = INTRC 10 = INTOSC 8 MHz source 01 = Timer1 oscillator 00 = LCD regulator disabled 2010 Microchip Technology Inc. x = Bit is unknown DS39770C-page 169 PIC18F85J90 FAMILY 16.3.3 BIAS CONFIGURATIONS M0 supports Static and 1/3 Bias types. Generation of the voltage levels for 1/3 Bias is handled automatically, but must be configured in software. PIC18F85J90 family devices have four distinct circuit configurations for LCD bias generation: * * * * M0 is enabled by selecting a valid regulator clock source (CKSEL<1:0> set to any value except `00') and setting the CPEN bit. If static Bias type is required, the MODE13 bit must be cleared. M0: Regulator with Boost M1: Regulator without Boost M2: Resistor Ladder with Software Contrast M3: Resistor Ladder with Hardware Contrast 16.3.3.1 16.3.3.2 M0 (Regulator with Boost) In M0 operation, the LCD charge pump feature is enabled. This allows the regulator to generate voltages up to +3.6V to the LCD (as measured at LCDBIAS3). M0 uses a flyback capacitor connected between VLCAP1 and VLCAP2, as well as filter capacitors on LCDBIAS0 through LCDBIAS3, to obtain the required voltage boost (Figure 16-3). Note: The BIAS<2:0> bits can still be used to adjust contrast in software by changing VBIAS. As with M0, changing these bits changes the offset between LCDBIAS0 and VSS. In M1, this is reflected in the change between the LCDBIAS0 and the voltage tied to LCDBIAS3. Thus, if VDD should change, VBIAS will also change; where in M0, the level of VBIAS is constant. When the device is put to Sleep while operating in M0 or M1 mode, make sure that the Bias capacitors are fully discharged to get the lowest Sleep current. The output voltage (VBIAS) is the difference of potential between LCDBIAS3 and LCDBIAS0. It is set by the BIAS<2:0> bits which adjust the offset between LCDBIAS0 and VSS. The flyback capacitor (CFLY) acts as a charge storage element for large LCD loads. This mode is useful in those cases where the voltage requirements of the LCD are higher than the microcontroller's VDD. It also permits software control of the display's contrast by adjustment of bias voltage by changing the value of the BIAS bits. FIGURE 16-3: M1 (Regulator without Boost) M1 operation is similar to M0, but does not use the LCD charge pump. It can provide VBIAS up to the voltage level supplied directly to LCDBIAS3. It can be used in cases where VDD for the application is expected to never drop below a level that can provide adequate contrast for the LCD. The connection of external components is very similar to M0, except that LCDBIAS3 must be tied directly to VDD (Figure 16-3). Like M0, M1 supports Static and 1/3 Bias types. Generation of the voltage levels for 1/3 Bias is handled automatically but must be configured in software. M1 is enabled by selecting a valid regulator clock source (CKSEL<1:0> set to any value except `00') and clearing the CPEN bit. If 1/3 Bias type is required, the MODE13 bit should also be set. LCD REGULATOR CONNECTIONS FOR M0 AND M1 CONFIGURATIONS VDD PIC18F85J90 VDD AVDD VLCAP1 VLCAP2 LCDBIAS3 LCDBIAS2 LCDBIAS1 LCDBIAS0 VDD C3 0.047 F(1) C2 0.047 F(1) C2 0.047 F(1) C1 0.047 F(1) C1 0.047 F(1) C0 0.047 F(1) C0 0.047 F(1) Mode 0 (VBIAS up to 3.6V) Note 1: CFLY 0.047 F(1) CFLY 0.047 F(1) Mode 1 (VBIAS VDD) These values are provided for design guidance only; they should be optimized for the application by the designer based on the actual LCD specifications. DS39770C-page 170 2010 Microchip Technology Inc. PIC18F85J90 FAMILY 16.3.3.3 M2 (Resistor Ladder with Software Contrast) configuration of the resistor ladder. Most applications using M2 will use a 1/3 or 1/2 Bias type. While Static Bias can also be used, it offers extremely limited contrast range and additional current consumption over other bias generation modes. M2 operation also uses the LCD regulator but disables the charge pump. The regulator's internal voltage reference remains active as a way to regulate contrast. It is used in cases where the current requirements of the LCD exceed the capacity of the regulator's charge pump. Like M1, the LCDBIAS bits can be used to control contrast, limited by the level of VDD supplied to the device. Also, since there is no capacitor required across VLCAP1 and VLCAP2, these pins are available as digital I/O ports, RG2 and RG3. In this configuration, the LCD bias voltage levels are created by an external resistor voltage divider connected across LCDBIAS0 through LCDBIAS3, with the top of the divider tied to VDD (Figure 16-4). The potential at the bottom of the ladder is determined by the LCD regulator's voltage reference, tied internally to LCDBIAS0. The bias type is determined by the voltages on the LCDBIAS pins, which are controlled by the FIGURE 16-4: M2 is selected by clearing the CKSEL<1:0> bits and setting the CPEN bit. RESISTOR LADDER CONNECTIONS FOR CONFIGURATION M2 PIC18F85J90 VDD AVDD LCDBIAS3 10 k(1) 10 k(1) LCDBIAS2 10 k(1) LCDBIAS1 10 k(1) 10 k(1) LCDBIAS0 1/2 Bias Bias Level at Pin Note 1: 1/3 Bias Bias Type 1/2 Bias 1/3 Bias LCDBIAS0 (Internal low reference voltage) (Internal low reference voltage) LCDBIAS1 1/2 VBIAS 1/3 VBIAS LCDBIAS2 1/2 VBIAS 2/3 VBIAS LCDBIAS3 VBIAS (up to AVDD) VBIAS (up to AVDD) These values are provided for design guidance only; they should be optimized for the application by the designer based on the actual LCD specifications. 2010 Microchip Technology Inc. DS39770C-page 171 PIC18F85J90 FAMILY 16.3.3.4 M3 (Hardware Contrast) In M3, the LCD regulator is completely disabled. Like M2, LCD bias levels are tied to AVDD, and are generated using an external divider. The difference is that the internal voltage reference is also disabled and the bottom of the ladder is tied to ground (VSS); see Figure 16-5. The value of the resistors and the difference between VSS and VDD determine the contrast range; no software adjustment is possible. This configuration is also used where the LCD's current requirements exceed the capacity of the charge pump, and software contrast control is not needed. FIGURE 16-5: Depending on the bias type required, resistors are connected between some or all of the pins. A potentiometer can also be connected between LCDBIAS3 and VDD to allow for hardware controlled contrast adjustment. M3 is selected by clearing the CKSEL<1:0> and CPEN bits. RESISTOR LADDER CONNECTIONS FOR CONFIGURATION M3 PIC18F85J90 VDD AVDD (2) LCDBIAS3 10 k(1) 10 k(1) LCDBIAS2 10 k(1) LCDBIAS1 10 k(1) 10 k(1) LCDBIAS0 Static Bias Bias Level at Pin Note 1: 2: 1/2 Bias 1/3 Bias Bias Type Static 1/2 Bias 1/3 Bias LCDBIAS0 AVSS AVSS AVSS LCDBIAS1 AVSS 1/2 AVDD 1/3 AVDD LCDBIAS2 AVDD 1/2 AVDD 2/3 AVDD LCDBIAS3 AVDD AVDD AVDD These values are provided for design guidance only; they should be optimized for the application by the designer based on the actual LCD specifications. Potentiometer for manual contrast adjustment is optional; it may be omitted entirely. DS39770C-page 172 2010 Microchip Technology Inc. PIC18F85J90 FAMILY 16.3.4 DESIGN CONSIDERATIONS FOR THE LCD CHARGE PUMP When designing applications that use the LCD regulator with the charge pump enabled, users must always consider both the dynamic current and RMS (static) current requirements of the display, and what the charge pump can deliver. Both dynamic and static current can be determined by Equation 16-1: EQUATION 16-1: STATIC AND DYNAMIC CURRENT I=Cx dV dT For dynamic current, C is the value of the capacitors attached to LCDBIAS3 and LCDBIAS2. The variable, dV, is the voltage drop allowed on C2 and C3 during a voltage switch on the LCD display, and dT is the duration of the transient current after a clock pulse occurs. For practical design purposes, these will be assumed to be 0.047 F for C, 0.1V for dV and 1 s for dT. This yields a dynamic current of 4.7 mA for 1 s. RMS current is determined by the value of CFLY for C, the voltage across VLCAP1 and VLCAP2 for dV and the regulator clock period (TPER) for dT. Assuming CFLY of 0.047 F, a value of 1.02V across CFLY and TPER of 30 s, the maximum theoretical static current will be 1.8 mA. Since the charge pump must charge five capacitors, the maximum current becomes 360 A. For a real-world assumption of 50% efficiency, this yields a practical current of 180 A. Users should compare the calculated current capacity against the requirements of the LCD. While dV and dT are relatively fixed by device design, the values of CFLY and the capacitors on the LCDBIAS pins can be changed to increase or decrease current. As always, any changes should be evaluated in the actual circuit for its impact on the application. 16.4 LCD Multiplex Types The LCD driver module can be configured into four multiplex types: * * * * Static (only COM0 used) 1/2 multiplex (COM0 and COM1 are used) 1/3 multiplex (COM0, COM1 and COM2 are used) 1/4 multiplex (all COM0, COM1, COM2 and COM3 are used) The number of active commons used is configured by the LMUX<1:0> bits (LCDCON<1:0>), which determines the function of the PORTE<6:4> pins (see Table 16-3 for details). If the pin is configured as a COM drive, the port I/O function is disabled and the TRIS setting of that pin is overridden. Note: On a Power-on Reset, the LMUX<1:0> bits are `00'. TABLE 16-3: PORTE<6:4> FUNCTION LMUX<1:0> PORTE<6> PORTE<5> PORTE<4> 00 Digital I/O Digital I/O Digital I/O 01 Digital I/O Digital I/O COM1 Driver 10 Digital I/O 11 16.5 COM2 Driver COM1 Driver COM3 Driver COM2 Driver COM1 Driver Segment Enables The LCDSEx registers are used to select the pin function for each segment pin. Setting a bit configures the corresponding pin to function as a segment driver. LCDSEx registers do not override the TRIS bit settings, so the TRIS bits must be configured as input for that pin. Note: 16.6 On a Power-on Reset, these pins are configured as digital I/O. Pixel Control The LCDDATAx registers contain bits which define the state of each pixel. Each bit defines one unique pixel. Table 16-2 shows the correlation of each bit in the LCDDATAx registers to the respective common and segment signals. Any LCD pixel location not being used for display can be used as general purpose RAM. 2010 Microchip Technology Inc. DS39770C-page 173 PIC18F85J90 FAMILY 16.7 LCD Frame Frequency 16.8 The rate at which the COM and SEG outputs changes is called the LCD frame frequency. Frame frequency is set by the LP<3:0> bits (LCDPS<3:0>), and is also affected by the Multiplex mode being used. The relationship between the Multiplex mode, LP bits setting and frame rate is shown in Table 16-4 and Table 16-5. TABLE 16-4: FRAME FREQUENCY FORMULAS Multiplex Mode Frame Frequency (Hz) Static Clock source/(4 x 1 x (LP3:LP0 + 1)) 1/2 Clock source/(2 x 2 x (LP3:LP0 + 1)) 1/3 Clock source/(1 x 3 x (LP3:LP0 + 1)) 1/4 Clock source/(1 x 4 x (LP3:LP0 + 1)) TABLE 16-5: LP<3:0> APPROXIMATE FRAME FREQUENCY (IN Hz) FOR LP PRESCALER SETTINGS Multiplex Mode Static 1/2 1/3 1/4 1 125 125 167 125 2 83 83 111 83 3 62 62 83 62 4 50 50 67 50 5 42 42 56 42 6 36 36 48 36 7 31 31 42 31 LCD Waveform Generation LCD waveform generation is based on the principle that the net AC voltage across the dark pixel should be maximized and the net AC voltage across the clear pixel should be minimized. The net DC voltage across any pixel should be zero. The COM signal represents the time slice for each common, while the SEG contains the pixel data. The pixel signal (COM-SEG) will have no DC component and it can take only one of the two rms values. The higher rms value will create a dark pixel and a lower rms value will create a clear pixel. As the number of commons increases, the delta between the two rms values decreases. The delta represents the maximum contrast that the display can have. The LCDs can be driven by two types of waveform: Type-A and Type-B. In the Type-A waveform, the phase changes within each common type, whereas in the Type-B waveform, the phase changes on each frame boundary. Thus, the Type-A waveform maintains 0 VDC over a single frame, whereas the Type-B waveform takes two frames. Note 1: If the power-managed Sleep mode is invoked while the LCD Sleep bit is set (LCDCON<6> is `1'), take care to execute Sleep only when the VDC on all the pixels is `0'. 2: When the LCD clock source is the system clock, the LCD module will go to Sleep if the microcontroller goes into Sleep mode, regardless of the setting of the SPLEN bit. Thus, always take care to see that the VDC on all pixels is `0' whenever Sleep mode is invoked. Figure 16-6 through Figure 16-16 provide waveforms for static, half multiplex, one-third multiplex and quarter multiplex drives for Type-A and Type-B waveforms. DS39770C-page 174 2010 Microchip Technology Inc. PIC18F85J90 FAMILY FIGURE 16-6: TYPE-A/TYPE-B WAVEFORMS IN STATIC DRIVE V1 COM0 V0 COM0 V1 SEG0 V0 V1 SEG1 SEG0 SEG2 SEG7 SEG6 SEG5 SEG4 SEG3 SEG1 V0 V1 V0 COM0-SEG0 -V1 COM0-SEG1 V0 1 Frame 2010 Microchip Technology Inc. DS39770C-page 175 PIC18F85J90 FAMILY FIGURE 16-7: TYPE-A WAVEFORMS IN 1/2 MUX, 1/2 BIAS DRIVE V2 COM0 V1 V0 COM1 V2 COM0 COM1 V1 V0 V2 V1 SEG0 V0 SEG0 SEG1 SEG2 SEG3 V2 V1 SEG1 V0 V2 V1 V0 COM0-SEG0 -V1 -V2 V2 V1 V0 COM0-SEG1 -V1 -V2 1 Frame DS39770C-page 176 2010 Microchip Technology Inc. PIC18F85J90 FAMILY FIGURE 16-8: TYPE-B WAVEFORMS IN 1/2 MUX, 1/2 BIAS DRIVE V2 V1 COM0 COM1 V0 COM0 V2 COM1 V1 V0 V2 SEG0 V1 SEG0 SEG1 SEG2 SEG3 V0 V2 SEG1 V1 V0 V2 V1 V0 COM0-SEG0 -V1 -V2 V2 V1 V0 COM0-SEG1 -V1 -V2 2 Frames 2010 Microchip Technology Inc. DS39770C-page 177 PIC18F85J90 FAMILY FIGURE 16-9: TYPE-A WAVEFORMS IN 1/2 MUX, 1/3 BIAS DRIVE V3 V2 COM0 V1 COM1 V0 V3 COM0 V2 COM1 V1 V0 V3 V2 SEG0 V1 V0 SEG0 SEG1 SEG2 SEG3 V3 V2 SEG1 V1 V0 V3 V2 V1 V0 COM0-SEG0 -V1 -V2 -V3 V3 V2 V1 V0 COM0-SEG1 -V1 -V2 1 Frame DS39770C-page 178 -V3 2010 Microchip Technology Inc. PIC18F85J90 FAMILY FIGURE 16-10: TYPE-B WAVEFORMS IN 1/2 MUX, 1/3 BIAS DRIVE V3 V2 COM0 V1 COM1 V0 V3 COM0 V2 COM1 V1 V0 V3 V2 SEG0 V1 V0 SEG0 SEG1 SEG2 SEG3 V3 V2 SEG1 V1 V0 V3 V2 V1 V0 COM0-SEG0 -V1 -V2 -V3 V3 V2 V1 V0 COM0-SEG1 -V1 -V2 2 Frames 2010 Microchip Technology Inc. -V3 DS39770C-page 179 PIC18F85J90 FAMILY FIGURE 16-11: TYPE-A WAVEFORMS IN 1/3 MUX, 1/2 BIAS DRIVE V2 COM0 V1 V0 COM2 V2 COM1 V1 V0 COM1 COM0 V2 COM2 V1 V0 V2 SEG0 SEG2 V1 SEG0 SEG1 SEG2 V0 V2 SEG1 V1 V0 V2 V1 V0 COM0-SEG0 -V1 -V2 V2 V1 V0 COM0-SEG1 -V1 -V2 1 Frame DS39770C-page 180 2010 Microchip Technology Inc. PIC18F85J90 FAMILY FIGURE 16-12: TYPE-B WAVEFORMS IN 1/3 MUX, 1/2 BIAS DRIVE V2 COM0 V1 V0 COM2 V2 COM1 V1 COM1 V0 COM0 V2 COM2 V1 V0 V2 V1 V0 SEG0 SEG1 SEG2 SEG0 V2 SEG1 V1 V0 V2 V1 V0 COM0-SEG0 -V1 -V2 V2 V1 V0 COM0-SEG1 -V1 -V2 2 Frames 2010 Microchip Technology Inc. DS39770C-page 181 PIC18F85J90 FAMILY FIGURE 16-13: TYPE-A WAVEFORMS IN 1/3 MUX, 1/3 BIAS DRIVE V3 V2 COM0 V1 V0 V3 COM2 V2 COM1 V1 COM1 V0 COM0 V3 V2 COM2 V1 V0 V3 V2 V1 V0 SEG0 SEG1 SEG2 SEG0 SEG2 V3 V2 SEG1 V1 V0 V3 V2 V1 V0 COM0-SEG0 -V1 -V2 -V3 V3 V2 V1 V0 COM0-SEG1 -V1 -V2 -V3 1 Frame DS39770C-page 182 2010 Microchip Technology Inc. PIC18F85J90 FAMILY FIGURE 16-14: TYPE-B WAVEFORMS IN 1/3 MUX, 1/3 BIAS DRIVE V3 V2 COM0 V1 V0 V3 COM2 V2 COM1 V1 COM1 V0 COM0 V3 V2 COM2 V1 V0 V3 V2 V1 V0 SEG0 SEG1 SEG2 SEG0 V3 V2 SEG1 V1 V0 V3 V2 V1 V0 COM0-SEG0 -V1 -V2 -V3 V3 V2 V1 V0 COM0-SEG1 -V1 -V2 -V3 2 Frames 2010 Microchip Technology Inc. DS39770C-page 183 PIC18F85J90 FAMILY FIGURE 16-15: TYPE-A WAVEFORMS IN 1/4 MUX, 1/3 BIAS DRIVE COM3 COM2 COM1 COM0 V3 V2 V1 V0 COM1 V3 V2 V1 V0 COM2 V3 V2 V1 V0 COM3 V3 V2 V1 V0 SEG0 V3 V2 V1 V0 SEG1 V3 V2 V1 V0 COM0-SEG0 V3 V2 V1 V0 -V1 -V2 -V3 COM0-SEG1 V3 V2 V1 V0 -V1 -V2 -V3 SEG0 SEG1 COM0 1 Frame DS39770C-page 184 2010 Microchip Technology Inc. PIC18F85J90 FAMILY FIGURE 16-16: TYPE-B WAVEFORMS IN 1/4 MUX, 1/3 BIAS DRIVE COM3 COM2 COM1 COM0 V3 V2 V1 V0 COM1 V3 V2 V1 V0 COM2 V3 V2 V1 V0 COM3 V3 V2 V1 V0 SEG0 V3 V2 V1 V0 SEG1 V3 V2 V1 V0 COM0-SEG0 V3 V2 V1 V0 -V1 -V2 -V3 COM0-SEG1 V3 V2 V1 V0 -V1 -V2 -V3 SEG0 SEG1 COM0 2 Frames 2010 Microchip Technology Inc. DS39770C-page 185 PIC18F85J90 FAMILY 16.9 LCD Interrupts When the LCD driver is running with Type-B waveforms, and the LMUX<1:0> bits are not equal to `00', there are some additional issues that must be addressed. Since the DC voltage on the pixel takes two frames to maintain zero volts, the pixel data must not change between subsequent frames. If the pixel data were allowed to change, the waveform for the odd frames would not necessarily be the complement of the waveform generated in the even frames and a DC component would be introduced into the panel. Therefore, when using Type-B waveforms, the user must synchronize the LCD pixel updates to occur within a subframe after the frame interrupt. The LCD timing generation provides an interrupt that defines the LCD frame timing. This interrupt can be used to coordinate the writing of the pixel data with the start of a new frame. Writing pixel data at the frame boundary allows a visually crisp transition of the image. This interrupt can also be used to synchronize external events to the LCD. For example, the interface to an external segment driver can be synchronized for segment data update to the LCD frame. A new frame is defined to begin at the leading edge of the COM0 common signal. The interrupt will be set immediately after the LCD controller completes accessing all pixel data required for a frame. This will occur at a fixed interval before the frame boundary (TFINT), as shown in Figure 16-17. The LCD controller will begin to access data for the next frame within the interval from the interrupt to when the controller begins to access data after the interrupt (TFWR). New data must be written within TFWR, as this is when the LCD controller will begin to access the data for the next frame. FIGURE 16-17: To correctly sequence writing while in Type-B, the interrupt will only occur on complete phase intervals. If the user attempts to write when the write is disabled, the WERR (LCDCON<5>) bit is set. Note: The interrupt is not generated when the Type-A waveform is selected and when the Type-B with no multiplex (static) is selected. EXAMPLE WAVEFORMS AND INTERRUPT TIMING IN QUARTER DUTY CYCLE DRIVE LCD Interrupt Occurs Controller Accesses Next Frame Data COM0 V3 V2 V1 V0 COM1 V3 V2 V1 V0 COM2 V3 V2 V1 V0 V3 V2 V1 V0 COM3 2 Frames TFINT Frame Boundary Frame Boundary TFWR Frame Boundary TFWR = TFRAME/2 * (LMUX<1:0> + 1) + TCY/2 TFINT = (TFWR/2 - (2 TCY + 40 ns)) Minimum = 1.5(TFRAME/4) - (2 TCY + 40 ns) (TFWR/2 - (1 TCY + 40 ns)) Maximum = 1.5(TFRAME/4) - (1 TCY + 40 ns) DS39770C-page 186 2010 Microchip Technology Inc. PIC18F85J90 FAMILY 16.10 Operation During Sleep The LCD module can operate during Sleep. The selection is controlled by the SLPEN bit (LCDCON<6>). Setting the SLPEN bit allows the LCD module to go to Sleep. Clearing the SLPEN bit allows the module to continue to operate during Sleep. If a SLEEP instruction is executed and SLPEN = 1, the LCD module will cease all functions and go into a very low-current consumption mode. The module will stop operation immediately and drive the minimum LCD voltage on both segment and common lines. Figure 16-18 shows this operation. To ensure that no DC component is introduced on the panel, the SLEEP instruction should be executed immediately after a LCD frame boundary. The LCD interrupt can be used to determine the frame boundary. See Section 16.9 "LCD Interrupts" for the formulas to calculate the delay. If a SLEEP instruction is executed and SLPEN = 0, the module will continue to display the current contents of the LCDDATA registers. To allow the module to continue operation while in Sleep, the clock source must be either the Timer1 oscillator or one of the FIGURE 16-18: internal oscillators (either INTRC or INTOSC as the default system clock). While in Sleep, the LCD data cannot be changed. The LCD module current consumption will not decrease in this mode; however, the overall consumption of the device will be lower due to shut down of the core and other peripheral functions. If the system clock is selected and the module is not configured for Sleep operation, the module will ignore the SLPEN bit and stop operation immediately. The minimum LCD voltage will then be driven onto the segments and commons 16.10.1 USING THE LCD REGULATOR DURING SLEEP Applications that use the LCD regulator for bias generation may not achieve the same degree of power reductions in Sleep mode when compared to applications using Mode 3 (resistor ladder) biasing. This is particularly true with Mode 0 operation, where the charge pump is active. If Modes 0, 1 or 2 are used for bias generation, software contrast control will not be available. SLEEP ENTRY/EXIT WHEN SLPEN = 1 OR CS<1:0> = 00 V3 V2 V1 COM0 V0 V3 V2 V1 V0 COM1 V3 V2 V1 V0 COM2 V3 V2 V1 V0 SEG0 2 Frames SLEEP Instruction Execution 2010 Microchip Technology Inc. Wake-up DS39770C-page 187 PIC18F85J90 FAMILY 16.11 Configuring the LCD Module 6. The following is the sequence of steps to configure the LCD module. 1. 2. 3. 4. 5. Select the frame clock prescale using bits, LP<3:0> (LCDPS<3:0>). Configure the appropriate pins to function as segment drivers using the LCDSEx registers. Configure the appropriate pins as inputs using the TRISx registers. Configure the LCD module for the following using the LCDCON register: * Multiplex and Bias mode (LMUX<1:0>) * Timing source (CS<1:0>) * Sleep mode (SLPEN) Write initial values to Pixel Data registers, LCDDATA0 through LCDDATA23. 7. 8. DS39770C-page 188 Configure the LCD Regulator: a) If M2 or M3 bias configuration is to be used, turn off the regulator by setting CKSEL<1:0> (LCDREG<1:0>) to `00'. Set or clear the CPEN bit (LCDREG<6>) to select Mode 2 or Mode 3, as appropriate. b) If M0 or M1 bias generation is to be used: * Set the VBIAS level using the BIAS<2:0> bits (LCDREG<5:3>). * Set or clear the CPEN bit to enable or disable the charge pump. * Set or clear the MODE13 bit (LCDREG<2>) to select the Bias mode. * Select a regulator clock source using the CKSEL<1:0> bits. Clear the LCD Interrupt Flag, LCDIF (PIR3<6>), and if desired, enable the interrupt by setting the LCDIE bit (PIE3<6>). Enable the LCD module by setting the LCDEN bit (LCDCON<7>). 2010 Microchip Technology Inc. PIC18F85J90 FAMILY TABLE 16-6: Name REGISTERS ASSOCIATED WITH LCD OPERATION Bit 7 Bit 6 Bit 5 Bit 3 Bit 2 Bit 1 Bit 0 Reset Values on Page INT0IE RBIE TMR0IF INT0IF RBIF 57 PIR3 -- LCDIF RC2IF TX2IF -- CCP2IF CCP1IF -- 60 PIE3 -- LCDIE RC2IE TX2IE -- CCP2IE CCP1IE -- 60 IPR3 -- LCDIP RC2IP TX2IP -- CCP2IP CCP1IP -- 60 INTCON GIE/GIEH PEIE/GIEL TMR0IE Bit 4 IPEN -- CM RI TO PD POR BOR 58 S47C3 S46C3 S45C3 S44C3 S43C3 S42C3 S41C3 S40C3 61 LCDDATA22 S39C3(1) S38C3(1) S37C3(1) S36C3(1) S35C3(1) S34C3(1) S33C3(1) S32C3 61 LCDDATA21 S31C3 S30C3 S29C3 S28C3 S27C3 S26C3 S25C3 S24C3 61 LCDDATA20 S23C3 S22C3 S21C3 S20C3 S19C3 S18C3 S17C3 S16C3 61 LCDDATA19 S15C3 S14C3 S13C3 S12C3 S11C3 S10C3 S09C3 S08C3 61 LCDDATA18 S07C3 S06C3 S05C3 S04C3 S03C3 S02C3 S01C3 S00C3 61 LCDDATA17(1) S47C2 S46C2 S45C2 S44C2 S43C2 S42C2 S41C2 S40C2 61 LCDDATA16 S39C2(1) S38C2(1) S37C2(1) S36C2(1) S35C2(1) S34C2(1) S33C2(1) S32C2 61 LCDDATA15 S31C2 S30C2 S29C2 S28C2 S27C2 S26C2 S25C2 S24C2 61 LCDDATA14 S23C2 S22C2 S21C2 S20C2 S19C2 S18C2 S17C2 S16C2 61 LCDDATA13 S15C2 S14C2 S13C2 S12C2 S11C2 S10C2 S09C2 S08C2 61 LCDDATA12 S07C2 S06C2 S05C2 S04C2 S03C2 S02C2 S01C2 S00C2 61 LCDDATA11(1) S47C1 S46C1 S45C1 S44C1 S43C1 S42C1 S41C1 S40C1 61 LCDDATA10 S39C1(1) S38C1(1) S37C1(1) S36C1(1) S35C1(1) S34C1(1) S33C1(1) S32C1 61 LCDDATA9 S31C1 S30C1 S29C1 S28C1 S27C1 S26C1 S25C1 S24C1 61 LCDDATA8 S23C1 S22C1 S21C1 S20C1 S19C1 S18C1 S17C1 S16C1 61 LCDDATA7 S15C1 S14C1 S13C1 S12C1 S11C1 S10C1 S09C1 S08C1 61 LCDDATA6 S07C1 S06C1 S05C1 S04C1 S03C1 S02C1 S01C1 S00C1 61 LCDDATA5(1) S47C0 S46C0 S45C0 S44C0 S43C0 S42C0 S41C0 S40C0 61 S38C0(1) S37C0(1) S36C0(1) S35C0(1) S34C0(1) S33C0(1) RCON LCDDATA23(1) (1) S32C0 59 LCDDATA3 S31C0 S30C0 S29C0 S28C0 S27C0 S26C0 S25C0 S24C0 59 LCDDATA2 S23C0 S22C0 S21C0 S20C0 S19C0 S18C0 S17C0 S16C0 59 LCDDATA1 S15C0 S14C0 S13C0 S12C0 S11C0 S10C0 S09C0 S08C0 59 LCDDATA0 S07C0 S06C0 S05C0 S04C0 S03C0 S02C0 S01C0 S00C0 59 LCDSE5(1) SE47 SE46 SE45 SE44 SE43 SE42 SE41 SE40 59 SE38(1) SE37(1) SE36(1) SE35(1) SE34(1) SE33(1) SE32 59 SE30 SE29 SE28 SE27 SE26 SE25 SE24 59 LCDDATA4 LCDSE4 LCDSE3 S39C0 SE39 (1) SE31 LCDSE2 SE23 SE22 SE21 SE20 SE19 SE18 SE17 SE16 59 LCDSE1 SE15 SE14 SE13 SE12 SE11 SE10 SE09 SE08 59 LCDSE0 SE07 SE06 SE05 SE04 SE03 SE02 SE01 SE00 59 LCDCON LCDEN SLPEN WERR -- CS1 CS0 LMUX1 LMUX0 59 WFT BIASMD LCDA WA LP3 LP2 LP1 LP0 59 -- CPEN BIAS2 BIAS1 BIAS0 MODE13 CKSEL1 CKSEL0 LCDPS LCDREG Legend: -- = unimplemented, read as `0'. Shaded cells are not used for LCD operation. Note 1: These registers or individual bits are unimplemented on 64-pin devices. 2010 Microchip Technology Inc. DS39770C-page 189 PIC18F85J90 FAMILY NOTES: DS39770C-page 190 2010 Microchip Technology Inc. PIC18F85J90 FAMILY 17.0 17.1 MASTER SYNCHRONOUS SERIAL PORT (MSSP) MODULE Figure 17-1 shows the block diagram of the MSSP module when operating in SPI mode. Note: Master SSP (MSSP) Module Overview The Master Synchronous Serial Port (MSSP) module is a serial interface, useful for communicating with other peripheral or microcontroller devices. These peripheral devices may be serial EEPROMs, shift registers, display drivers, A/D Converters, etc. The MSSP module can operate in one of two modes: Disabling the MSSP module by clearing the SSPEN (SSPCON1<5>) bit may not reset the module. It is recommended to clear the SSPSTAT, SSPCON1 and SSPCON2 registers and select the mode prior to setting the SSPEN bit to enable the MSSP module. FIGURE 17-1: * Serial Peripheral Interface (SPI) * Inter-Integrated Circuit (I2CTM) - Full Master mode - Slave mode (with general address call) MSSP BLOCK DIAGRAM (SPI MODE) Internal Data Bus Read Write SSPBUF reg The I2C interface supports the following modes in hardware: * Master mode * Multi-Master mode * Slave mode 17.2 SDI SSPSR reg SDO Control Registers Each MSSP module has three associated control registers. These include a status register (SSPSTAT) and two control registers (SSPCON1 and SSPCON2). The use of these registers and their individual bits differ significantly depending on whether the MSSP module is operated in SPI or I2C mode. SS SS Control Enable Edge Select 2 Additional details are provided under the individual sections. 17.3 Shift Clock bit 0 Clock Select SPI Mode The SPI mode allows 8 bits of data to be synchronously transmitted and received simultaneously. All four modes of SPI are supported. To accomplish communication, typically three pins are used: * Serial Data Out (SDO) - RC5/SDO * Serial Data In (SDI) - RC4/SDI/SDA * Serial Clock (SCK) - RC3/SCK/SCL SCK SSPM<3:0> SMP:CKE 4 TMR2 Output 2 2 ( Edge Select ) Prescaler TOSC 4, 16, 64 Data to TXx/RXx in SSPSR TRIS bit Additionally, a fourth pin may be used when in a Slave mode of operation: * Slave Select (SS) - RF7/SS Note: Disabling the MSSP module by clearing the SSPEN (SSPCON1<5>) bit may not reset the module. It is recommended to clear the SSPSTAT, SSPCON1 and SSPCON2 registers and select the mode prior to setting the SSPEN bit to enable the MSSP module. 2010 Microchip Technology Inc. DS39770C-page 191 PIC18F85J90 FAMILY 17.3.1 REGISTERS SSPSR is the shift register used for shifting data in or out. SSPBUF is the buffer register to which data bytes are written to or read from. Each MSSP module has four registers for SPI mode operation. These are: In receive operations, SSPSR and SSPBUF together create a double-buffered receiver. When SSPSR receives a complete byte, it is transferred to SSPBUF and the SSPIF interrupt is set. * MSSP Control Register 1 (SSPCON1) * MSSP Status Register (SSPSTAT) * MSSP Serial Receive/Transmit Buffer Register (SSPBUF) * MSSP Shift Register (SSPSR) - Not directly accessible During transmission, the SSPBUF is not double-buffered. A write to SSPBUF will write to both SSPBUF and SSPSR. SSPCON1 and SSPSTAT are the control and status registers in SPI mode operation. The SSPCON1 register is readable and writable. The lower 6 bits of the SSPSTAT are read-only. The upper two bits of the SSPSTAT are read/write. REGISTER 17-1: R/W-0 SMP SSPSTAT: MSSP STATUS REGISTER (SPI MODE) R/W-0 R-0 R-0 R-0 R-0 R0 R-0 (1) D/A P S R/W UA BF CKE bit 7 bit 0 Legend: R = Readable bit W = Writable bit U = Unimplemented bit, read as `0' -n = Value at POR `1' = Bit is set `0' = Bit is cleared x = Bit is unknown bit 7 SMP: Sample bit SPI Master mode: 1 = Input data sampled at end of data output time 0 = Input data sampled at middle of data output time SPI Slave mode: SMP must be cleared when SPI is used in Slave mode. bit 6 CKE: SPI Clock Select bit(1) 1 = Transmit occurs on transition from active to Idle clock state 0 = Transmit occurs on transition from Idle to active clock state bit 5 D/A: Data/Address bit Used in I2CTM mode only. bit 4 P: Stop bit Used in I2C mode only. This bit is cleared when the MSSP module is disabled, SSPEN is cleared. bit 3 S: Start bit Used in I2C mode only. bit 2 R/W: Read/Write Information bit Used in I2C mode only. bit 1 UA: Update Address bit Used in I2C mode only. bit 0 BF: Buffer Full Status bit (Receive mode only) 1 = Receive complete, SSPBUF is full 0 = Receive not complete, SSPBUF is empty Note 1: Polarity of clock state is set by the CKP bit (SSPCON1<4>). DS39770C-page 192 2010 Microchip Technology Inc. PIC18F85J90 FAMILY REGISTER 17-2: SSPCON1: MSSP CONTROL REGISTER 1 (SPI MODE) R/W-0 R/W-0 R/W-0 R/W-0 R/W-0 R/W-0 R/W-0 R/W-0 WCOL SSPOV(1) SSPEN(2) CKP SSPM3(3) SSPM2(3) SSPM1(3) SSPM0(3) bit 7 bit 0 Legend: R = Readable bit W = Writable bit U = Unimplemented bit, read as `0' -n = Value at POR `1' = Bit is set `0' = Bit is cleared x = Bit is unknown bit 7 WCOL: Write Collision Detect bit (Transmit mode only) 1 = The SSPBUF register is written while it is still transmitting the previous word (must be cleared in software) 0 = No collision bit 6 SSPOV: Receive Overflow Indicator bit(1) SPI Slave mode: 1 = A new byte is received while the SSPBUF register is still holding the previous data. In case of overflow, the data in SSPSR is lost. Overflow can only occur in Slave mode. The user must read the SSPBUF, even if only transmitting data, to avoid setting overflow (must be cleared in software). 0 = No overflow bit 5 SSPEN: Master Synchronous Serial Port Enable bit(2) 1 = Enables serial port and configures SCK, SDO, SDI and SS as serial port pins 0 = Disables serial port and configures these pins as I/O port pins bit 4 CKP: Clock Polarity Select bit 1 = Idle state for clock is a high level 0 = Idle state for clock is a low level bit 3-0 SSPM<3:0>: Master Synchronous Serial Port Mode Select bits(3) 0101 = SPI Slave mode, clock = SCK pin, SS pin control disabled, SS can be used as I/O pin 0100 = SPI Slave mode, clock = SCK pin, SS pin control enabled 0011 = SPI Master mode, clock = TMR2 output/2 0010 = SPI Master mode, clock = FOSC/64 0001 = SPI Master mode, clock = FOSC/16 0000 = SPI Master mode, clock = FOSC/4 Note 1: 2: 3: In Master mode, the overflow bit is not set since each new reception (and transmission) is initiated by writing to the SSPBUF register. When enabled, these pins must be properly configured as input or output. Bit combinations not specifically listed here are either reserved or implemented in I2CTM mode only. 2010 Microchip Technology Inc. DS39770C-page 193 PIC18F85J90 FAMILY 17.3.2 OPERATION When initializing the SPI, several options need to be specified. This is done by programming the appropriate control bits (SSPCON1<5:0> and SSPSTAT<7:6>). These control bits allow the following to be specified: * * * * Master mode (SCK is the clock output) Slave mode (SCK is the clock input) Clock Polarity (Idle state of SCK) Data Input Sample Phase (middle or end of data output time) * Clock Edge (output data on rising/falling edge of SCK) * Clock Rate (Master mode only) * Slave Select mode (Slave mode only) Each MSSP consists of a transmit/receive shift register (SSPSR) and a buffer register (SSPBUF). The SSPSR shifts the data in and out of the device, MSb first. The SSPBUF holds the data that was written to the SSPSR until the received data is ready. Once the 8 bits of data have been received, that byte is moved to the SSPBUF register. Then, the Buffer Full detect bit, BF (SSPSTAT<0>), and the MSSP Interrupt Flag bit, SSPIF, are set. This double-buffering of the received data (SSPBUF) allows the next byte to start reception before reading the data that was just received. Any write to the SSPBUF register during transmission/reception of data EXAMPLE 17-1: LOOP BTFSS BRA MOVF MOVWF MOVF MOVWF DS39770C-page 194 will be ignored and the Write Collision detect bit, WCOL (SSPCON1<7>), will be set. User software must clear the WCOL bit so that it can be determined if the following write(s) to the SSPBUF register completed successfully. When the application software is expecting to receive valid data, the SSPBUF should be read before the next byte of data to transfer is written to the SSPBUF. The Buffer Full bit, BF (SSPSTAT<0>), indicates when SSPBUF has been loaded with the received data (transmission is complete). When the SSPBUF is read, the BF bit is cleared. This data may be irrelevant if the SPI is only a transmitter. Generally, the MSSP interrupt is used to determine when the transmission/reception has completed. The SSPBUF must be read and/or written. If the interrupt method is not going to be used, then software polling can be done to ensure that a write collision does not occur. Example 17-1 shows the loading of the SSPBUF (SSPSR) for data transmission. The SSPSR is not directly readable or writable and can only be accessed by addressing the SSPBUF register. Additionally, the SSPSTAT register indicates the various status conditions. Note: To avoid lost data in Master mode, a read of the SSPBUF must be performed to clear the Buffer Full (BF) detect bit (SSPSTAT<0>) between each transmission. LOADING THE SSPBUF (SSPSR) REGISTER SSPSTAT, BF LOOP SSPBUF, W RXDATA TXDATA, W SSPBUF ;Has data been received (transmit complete)? ;No ;WREG reg = contents of SSPBUF ;Save in user RAM, if data is meaningful ;W reg = contents of TXDATA ;New data to xmit 2010 Microchip Technology Inc. PIC18F85J90 FAMILY 17.3.3 ENABLING SPI I/O To enable the serial port, MSSP Enable bit, SSPEN (SSPCON1<5>), must be set. To reset or reconfigure SPI mode, clear the SSPEN bit, reinitialize the SSPCON registers and then set the SSPEN bit. This configures the SDI, SDO, SCK and SS pins as serial port pins. For the pins to behave as the serial port function, some must have their data direction bits (in the TRIS register) appropriately programmed as follows: * SDI is automatically controlled by the SPI module * SDO must have TRISC<5> bit cleared * SCK (Master mode) must have TRISC<3> bit cleared * SCK (Slave mode) must have TRISC<3> bit set * SS must have TRISF<7> bit set Any serial port function that is not desired may be overridden by programming the corresponding data direction (TRIS) register to the opposite value. 17.3.4 OPEN-DRAIN OUTPUT OPTION The drivers for the SDO output and SCK clock pins can be optionally configured as open-drain outputs. This feature allows the voltage level on the pin to be pulled FIGURE 17-2: to a higher level through an external pull-up resistor, and allows the output to communicate with external circuits without the need for additional level shifters. The open-drain output option is controlled by the SPIOD bit (TRISG<7>). Setting the bit configures both pins for open-drain operation. 17.3.5 TYPICAL CONNECTION Figure 17-2 shows a typical connection between two microcontrollers. The master controller (Processor 1) initiates the data transfer by sending the SCK signal. Data is shifted out of both shift registers on their programmed clock edge and latched on the opposite edge of the clock. Both processors should be programmed to the same Clock Polarity (CKP), then both controllers would send and receive data at the same time. Whether the data is meaningful (or dummy data) depends on the application software. This leads to three scenarios for data transmission: * Master sends data-Slave sends dummy data * Master sends data-Slave sends data * Master sends dummy data-Slave sends data SPI MASTER/SLAVE CONNECTION SPI Master SSPM<3:0> = 00xx SPI Slave SSPM<3:0> = 010x SDO SDI Serial Input Buffer (SSPBUF) SDI Shift Register (SSPSR) MSb Serial Input Buffer (SSPBUF) LSb 2010 Microchip Technology Inc. Shift Register (SSPSR) MSb SCK PROCESSOR 1 SDO Serial Clock LSb SCK PROCESSOR 2 DS39770C-page 195 PIC18F85J90 FAMILY 17.3.6 MASTER MODE The master can initiate the data transfer at any time because it controls the SCK. The master determines when the slave (Processor 2, Figure 17-2) will broadcast data by the software protocol. In Master mode, the data is transmitted/received as soon as the SSPBUF register is written to. If the SPI is only going to receive, the SDO output could be disabled (programmed as an input). The SSPSR register will continue to shift in the signal present on the SDI pin at the programmed clock rate. As each byte is received, it will be loaded into the SSPBUF register as if a normal received byte (interrupts and status bits appropriately set). This could be useful in receiver applications as a "Line Activity Monitor" mode. FIGURE 17-3: The clock polarity is selected by appropriately programming the CKP bit (SSPCON1<4>). This, then, would give waveforms for SPI communication as shown in Figure 17-3, Figure 17-5 and Figure 17-6, where the MSB is transmitted first. In Master mode, the SPI clock rate (bit rate) is user-programmable to be one of the following: * * * * FOSC/4 (or TCY) FOSC/16 (or 4 * TCY) FOSC/64 (or 16 * TCY) Timer2 output/2 This allows a maximum data rate (at 40 MHz) of 10.00 Mbps. Figure 17-3 shows the waveforms for Master mode. When the CKE bit is set, the SDO data is valid before there is a clock edge on SCK. The change of the input sample is shown based on the state of the SMP bit. The time when the SSPBUF is loaded with the received data is shown. SPI MODE WAVEFORM (MASTER MODE) Write to SSPBUF SCK (CKP = 0 CKE = 0) SCK (CKP = 1 CKE = 0) 4 Clock Modes SCK (CKP = 0 CKE = 1) SCK (CKP = 1 CKE = 1) SDO (CKE = 0) bit 7 bit 6 bit 5 bit 4 bit 3 bit 2 bit 1 bit 0 SDO (CKE = 1) bit 7 bit 6 bit 5 bit 4 bit 3 bit 2 bit 1 bit 0 SDI (SMP = 0) bit 0 bit 7 Input Sample (SMP = 0) SDI (SMP = 1) bit 7 bit 0 Input Sample (SMP = 1) SSPIF SSPSR to SSPBUF DS39770C-page 196 Next Q4 Cycle after Q2 2010 Microchip Technology Inc. PIC18F85J90 FAMILY 17.3.7 SLAVE MODE In Slave mode, the data is transmitted and received as the external clock pulses appear on SCK. When the last bit is latched, the SSPIF interrupt flag bit is set. Before enabling the module in SPI Slave mode, the clock line must match the proper Idle state. The clock line can be observed by reading the SCK pin. The Idle state is determined by the CKP bit (SSPCON1<4>). While in Slave mode, the external clock is supplied by the external clock source on the SCK pin. This external clock must meet the minimum high and low times as specified in the electrical specifications. While in Sleep mode, the slave can transmit/receive data. When a byte is received, the device will wake-up from Sleep. 17.3.8 SLAVE SELECT SYNCHRONIZATION The SS pin allows a Synchronous Slave mode. The SPI must be in Slave mode with SS pin control enabled (SSPCON1<3:0> = 04h). When the SS pin is low, transmission and reception are enabled and the SDO pin is FIGURE 17-4: driven. When the SS pin goes high, the SDO pin is no longer driven, even if in the middle of a transmitted byte and becomes a floating output. External pull-up/pull-down resistors may be desirable depending on the application. Note 1: When the SPI is in Slave mode with SS pin control enabled (SSPCON1<3:0> = 0100), the SPI module will reset if the SS pin is set to VDD. 2: If the SPI is used in Slave mode with CKE set, then the SS pin control must be enabled. When the SPI module resets, the bit counter is forced to `0'. This can be done by either forcing the SS pin to a high level or clearing the SSPEN bit. To emulate two-wire communication, the SDO pin can be connected to the SDI pin. When the SPI needs to operate as a receiver, the SDO pin can be configured as an input. This disables transmissions from the SDO. The SDI can always be left as an input (SDI function) since it cannot create a bus conflict. SLAVE SYNCHRONIZATION WAVEFORM SS SCK (CKP = 0 CKE = 0) SCK (CKP = 1 CKE = 0) Write to SSPBUF SDO SDI (SMP = 0) bit 7 bit 6 bit 7 bit 0 bit 0 bit 7 bit 7 Input Sample (SMP = 0) SSPIF Interrupt Flag SSPSR to SSPBUF 2010 Microchip Technology Inc. Next Q4 Cycle after Q2 DS39770C-page 197 PIC18F85J90 FAMILY FIGURE 17-5: SPI MODE WAVEFORM (SLAVE MODE WITH CKE = 0) SS Optional SCK (CKP = 0 CKE = 0) SCK (CKP = 1 CKE = 0) Write to SSPBUF SDO SDI (SMP = 0) bit 7 bit 6 bit 5 bit 4 bit 3 bit 2 bit 1 bit 0 bit 0 bit 7 Input Sample (SMP = 0) SSPIF Interrupt Flag Next Q4 Cycle after Q2 SSPSR to SSPBUF FIGURE 17-6: SPI MODE WAVEFORM (SLAVE MODE WITH CKE = 1) SS Not Optional SCK (CKP = 0 CKE = 1) SCK (CKP = 1 CKE = 1) Write to SSPBUF SDO SDI (SMP = 0) bit 7 bit 7 bit 6 bit 5 bit 4 bit 3 bit 2 bit 1 bit 0 bit 0 Input Sample (SMP = 0) SSPIF Interrupt Flag SSPSR to SSPBUF DS39770C-page 198 Next Q4 Cycle after Q2 2010 Microchip Technology Inc. PIC18F85J90 FAMILY 17.3.9 OPERATION IN POWER-MANAGED MODES In SPI Master mode, module clocks may be operating at a different speed than when in Full-Power mode; in the case of Sleep mode, all clocks are halted. In Idle modes, a clock is provided to the peripherals. That clock should be from the primary clock source, the secondary clock (Timer1 oscillator at 32.768 kHz) or the INTRC source. See Section 3.3 "Clock Sources and Oscillator Switching" for additional information. In most cases, the speed that the master clocks SPI data is not important; however, this should be evaluated for each system. If MSSP interrupts are enabled, they can wake the controller from Sleep mode, or one of the Idle modes, when the master completes sending data. If an exit from Sleep or Idle mode is not desired, MSSP interrupts should be disabled. If the Sleep mode is selected, all module clocks are halted and the transmission/reception will remain in that state until the devices wakes. After the device returns to Run mode, the module will resume transmitting and receiving data. In SPI Slave mode, the SPI Transmit/Receive Shift register operates asynchronously to the device. This allows the device to be placed in any power-managed TABLE 17-2: Name INTCON mode and data to be shifted into the SPI Transmit/Receive Shift register. When all 8 bits have been received, the MSSP interrupt flag bit will be set and if enabled, will wake the device. 17.3.10 EFFECTS OF A RESET A Reset disables the MSSP module and terminates the current transfer. 17.3.11 BUS MODE COMPATIBILITY Table 17-1 shows the compatibility between the standard SPI modes and the states of the CKP and CKE control bits. TABLE 17-1: SPI BUS MODES Control Bits State Standard SPI Mode Terminology CKP CKE 0, 0 0 1 0, 1 0 0 1, 0 1 1 1, 1 1 0 There is also an SMP bit which controls when the data is sampled. REGISTERS ASSOCIATED WITH SPI OPERATION Bit 7 Bit 6 Bit 5 GIE/GIEH PEIE/GIEL TMR0IE Bit 4 Bit 3 Bit 2 Bit 1 Bit 0 Reset Values on page INT0IE RBIE TMR0IF INT0IF RBIF 57 PIR1 -- ADIF RC1IF TX1IF SSPIF -- TMR2IF TMR1IF 60 PIE1 -- ADIE RC1IE TX1IE SSPIE -- TMR2IE TMR1IE 60 IPR1 -- ADIP RC1IP TX1IP SSPIP -- TMR2IP TMR1IP 60 TRISC TRISC7 TRISC6 TRISC5 TRISC4 TRISC3 TRISC2 TRISC1 TRISC0 60 TRISF TRISF7 TRISF6 TRISF5 TRISF4 TRISF3 TRISF2 TRISF1 -- 60 TRISG SPIOD CCP2OD CCP1OD TRISG4 TRISG3 TRISG2 TRISG1 TRISG0 60 SSPBUF MSSP Receive Buffer/Transmit Register 58 SSPCON1 WCOL SSPOV SSPEN CKP SSPM3 SSPM2 SSPM1 SSPM0 58 SSPSTAT SMP CKE D/A P S R/W UA BF 58 Legend: Shaded cells are not used by the MSSP module in SPI mode. 2010 Microchip Technology Inc. DS39770C-page 199 PIC18F85J90 FAMILY 17.4 I2C Mode 17.4.1 The MSSP module in I 2C mode fully implements all master and slave functions (including general call support) and provides interrupts on Start and Stop bits in hardware to determine a free bus (multi-master function). The MSSP module implements the standard mode specifications as well as 7-bit and 10-bit addressing. Note: Disabling the MSSP module by clearing the SSPEN (SSPCON1<5>) bit may not reset the module. It is recommended to clear the SSPSTAT, SSPCON1 and SSPCON2 registers and select the mode prior to setting the SSPEN bit to enable the MSSP module. Two pins are used for data transfer: * Serial clock (SCL) - RC3/SCK/SCL * Serial data (SDA) - RC4/SDI/SDA The user must configure these pins as inputs by setting the TRISC<4:3> bits. FIGURE 17-7: MSSP BLOCK DIAGRAM (I2CTM MODE) Internal Data Bus Read Write SSPBUF reg SCL SDA Shift Clock LSb Match Detect The MSSP module has six registers for I2C operation. These are: * * * * MSSP Control Register 1 (SSPCON1) MSSP Control Register 2 (SSPCON2) MSSP Status Register (SSPSTAT) MSSP Serial Receive/Transmit Buffer Register (SSPBUF) * MSSP Shift Register (SSPSR) - Not directly accessible * MSSP Address Register (SSPADD) SSPCON1, SSPCON2 and SSPSTAT are the control and status registers in I2C mode operation. The SSPCON1 and SSPCON2 registers are readable and writable. The lower 6 bits of the SSPSTAT are read-only. The upper two bits of the SSPSTAT are read/write. Many of the bits in SSPCON2 assume different functions, depending on whether the module is operating in Master or Slave mode; bits<5:2> also assume different names in Slave mode. The different aspects of SSPCON2 are shown in Register 17-5 (for Master mode) and Register 17-6 (Slave mode). SSPSR is the shift register used for shifting data in or out. SSPBUF is the buffer register to which data bytes are written to or read from. SSPADD register holds the slave device address when the MSSP is configured in I2C Slave mode. When the MSSP is configured in Master mode, the lower seven bits of SSPADD act as the Baud Rate Generator reload value. In receive operations, SSPSR and SSPBUF together create a double-buffered receiver. When SSPSR receives a complete byte, it is transferred to SSPBUF and the SSPIF interrupt is set. SSPSR reg MSb REGISTERS Addr Match Address Mask During transmission, the SSPBUF is not double-buffered. A write to SSPBUF will write to both SSPBUF and SSPSR. SSPADD reg Start and Stop bit Detect DS39770C-page 200 Set, Reset S, P bits (SSPSTAT reg) 2010 Microchip Technology Inc. PIC18F85J90 FAMILY REGISTER 17-3: R/W-0 SSPSTAT: MSSP STATUS REGISTER (I2CTM MODE) R/W-0 SMP CKE R-0 R-0 R-0 R-0 R0 R-0 D/A (1) (1) R/W UA BF P S bit 7 bit 0 Legend: R = Readable bit W = Writable bit U = Unimplemented bit, read as `0' -n = Value at POR `1' = Bit is set `0' = Bit is cleared x = Bit is unknown bit 7 SMP: Slew Rate Control bit In Master or Slave mode: 1 = Slew rate control disabled for Standard Speed mode (100 kHz and 1 MHz) 0 = Slew rate control enabled for High-Speed mode (400 kHz) bit 6 CKE: SMBus Select bit In Master or Slave mode: 1 = Enable SMBus specific inputs 0 = Disable SMBus specific inputs bit 5 D/A: Data/Address bit In Master mode: Reserved. In Slave mode: 1 = Indicates that the last byte received or transmitted was data 0 = Indicates that the last byte received or transmitted was address bit 4 P: Stop bit(1) 1 = Indicates that a Stop bit has been detected last 0 = Stop bit was not detected last bit 3 S: Start bit(1) 1 = Indicates that a Start bit has been detected last 0 = Start bit was not detected last bit 2 R/W: Read/Write Information bit (I2C mode only) In Slave mode:(2) 1 = Read 0 = Write In Master mode:(3) 1 = Transmit is in progress 0 = Transmit is not in progress bit 1 UA: Update Address bit (10-Bit Slave mode only) 1 = Indicates that the user needs to update the address in the SSPADD register 0 = Address does not need to be updated bit 0 BF: Buffer Full Status bit In Transmit mode: 1 = SSPBUF is full 0 = SSPBUF is empty In Receive mode: 1 = SSPBUF is full (does not include the ACK and Stop bits) 0 = SSPBUF is empty (does not include the ACK and Stop bits) Note 1: 2: 3: This bit is cleared on Reset and when SSPEN is cleared. This bit holds the R/W bit information following the last address match. This bit is only valid from the address match to the next Start bit, Stop bit or not ACK bit. ORing this bit with SEN, RSEN, PEN, RCEN or ACKEN will indicate if the MSSP is in Active mode. 2010 Microchip Technology Inc. DS39770C-page 201 PIC18F85J90 FAMILY REGISTER 17-4: R/W-0 WCOL SSPCON1: MSSP CONTROL REGISTER 1 (I2CTM MODE) R/W-0 R/W-0 R/W-0 R/W-0 R/W-0 R/W-0 R/W-0 SSPOV SSPEN(1) CKP SSPM3 SSPM2 SSPM1 SSPM0 bit 7 bit 0 Legend: R = Readable bit W = Writable bit U = Unimplemented bit, read as `0' -n = Value at POR `1' = Bit is set `0' = Bit is cleared x = Bit is unknown bit 7 WCOL: Write Collision Detect bit In Master Transmit mode: 1 = A write to the SSPBUF register was attempted while the I2C conditions were not valid for a transmission to be started (must be cleared in software) 0 = No collision In Slave Transmit mode: 1 = The SSPBUF register is written while it is still transmitting the previous word (must be cleared in software) 0 = No collision In Receive mode (Master or Slave modes): This is a "don't care" bit. bit 6 SSPOV: Receive Overflow Indicator bit In Receive mode: 1 = A byte is received while the SSPBUF register is still holding the previous byte (must be cleared in software) 0 = No overflow In Transmit mode: This is a "don't care" bit in Transmit mode. bit 5 SSPEN: Master Synchronous Serial Port Enable bit(1) 1 = Enables the serial port and configures the SDA and SCL pins as the serial port pins 0 = Disables serial port and configures these pins as I/O port pins bit 4 CKP: SCK Release Control bit In Slave mode: 1 = Release clock 0 = Holds clock low (clock stretch), used to ensure data setup time In Master mode: Unused in this mode. bit 3-0 SSPM<3:0>: Synchronous Serial Port Mode Select bits 1111 = I2C Slave mode, 10-bit address with Start and Stop bit interrupts enabled 1110 = I2C Slave mode, 7-bit address with Start and Stop bit interrupts enabled 1011 = I2C Firmware Controlled Master mode (slave Idle) 1000 = I2C Master mode, clock = FOSC/(4 * (SSPADD + 1)) 0111 = I2C Slave mode, 10-bit address 0110 = I2C Slave mode, 7-bit address Bit combinations not specifically listed here are either reserved or implemented in SPI mode only. Note 1: When enabled, the SDA and SCL pins must be configured as inputs. DS39770C-page 202 2010 Microchip Technology Inc. PIC18F85J90 FAMILY REGISTER 17-5: SSPCON2: MSSP CONTROL REGISTER 2 (I2CTM MASTER MODE) R/W-0 R/W-0 R/W-0 R/W-0 R/W-0 R/W-0 R/W-0 R/W-0 GCEN ACKSTAT ACKDT(1) ACKEN(2) RCEN(2) PEN(2) RSEN(2) SEN(2) bit 7 bit 0 Legend: R = Readable bit W = Writable bit U = Unimplemented bit, read as `0' -n = Value at POR `1' = Bit is set `0' = Bit is cleared x = Bit is unknown bit 7 GCEN: General Call Enable bit Unused in Master mode. bit 6 ACKSTAT: Acknowledge Status bit (Master Transmit mode only) 1 = Acknowledge was not received from slave 0 = Acknowledge was received from slave bit 5 ACKDT: Acknowledge Data bit (Master Receive mode only)(1) 1 = Not Acknowledge 0 = Acknowledge bit 4 ACKEN: Acknowledge Sequence Enable bit(2) 1 = Initiate Acknowledge sequence on SDA and SCL pins and transmit ACKDT data bit. Automatically cleared by hardware. 0 = Acknowledge sequence Idle bit 3 RCEN: Receive Enable bit (Master Receive mode only)(2) 1 = Enables Receive mode for I2C 0 = Receive Idle bit 2 PEN: Stop Condition Enable bit(2) 1 = Initiate Stop condition on SDA and SCL pins. Automatically cleared by hardware. 0 = Stop condition Idle bit 1 RSEN: Repeated Start Condition Enable bit(2) 1 = Initiate Repeated Start condition on SDA and SCL pins. Automatically cleared by hardware. 0 = Repeated Start condition Idle bit 0 SEN: Start Condition Enable bit(2) 1 = Initiate Start condition on SDA and SCL pins. Automatically cleared by hardware. 0 = Start condition Idle Note 1: 2: Value that will be transmitted when the user initiates an Acknowledge sequence at the end of a receive. If the I2C module is active, these bits may not be set (no spooling) and the SSPBUF may not be written (or writes to the SSPBUF are disabled). 2010 Microchip Technology Inc. DS39770C-page 203 PIC18F85J90 FAMILY REGISTER 17-6: SSPCON2: MSSP CONTROL REGISTER 2 (I2CTM SLAVE MODE) R/W-0 R/W-0 R/W-0 R/W-0 R/W-0 R/W-0 R/W-0 R/W-0 GCEN ACKSTAT ADMSK5 ADMSK4 ADMSK3 ADMSK2 ADMSK1 SEN(1) bit 7 bit 0 Legend: R = Readable bit W = Writable bit U = Unimplemented bit, read as `0' -n = Value at POR `1' = Bit is set `0' = Bit is cleared x = Bit is unknown bit 7 GCEN: General Call Enable bit 1 = Enable interrupt when a general call address (0000h) is received in the SSPSR 0 = General call address disabled bit 6 ACKSTAT: Acknowledge Status bit Unused in Slave mode. bit 5-2 ADMSK<5:2>: Slave Address Mask Select bits 1 = Masking of corresponding bits of SSPADD enabled 0 = Masking of corresponding bits of SSPADD disabled bit 1 ADMSK1: Slave Address Least Significant bit(s) Mask Select bit In 7-Bit Address mode: 1 = Masking of SSPADD<1> only enabled 0 = Masking of SSPADD<1> only disabled In 10-Bit Address mode: 1 = Masking of SSPADD<1:0> enabled 0 = Masking of SSPADD<1:0> disabled bit 0 SEN: Stretch Enable bit(1) 1 = Clock stretching is enabled for both slave transmit and slave receive (stretch enabled) 0 = Clock stretching is disabled Note 1: If the I2C module is active, this bit may not be set (no spooling) and the SSPBUF may not be written (or writes to the SSPBUF are disabled). DS39770C-page 204 2010 Microchip Technology Inc. PIC18F85J90 FAMILY 17.4.2 OPERATION The MSSP module functions are enabled by setting the MSSP Enable bit, SSPEN (SSPCON1<5>). The SSPCON1 register allows control of the I 2C operation. Four mode selection bits (SSPCON1<3:0>) allow one of the following I 2C modes to be selected: 2 * I C Master mode, clock = (FOSC/4) x (SSPADD + 1) * I 2C Slave mode (7-bit address) * I 2C Slave mode (10-bit address) * I 2C Slave mode (7-bit address) with Start and Stop bit interrupts enabled * I 2C Slave mode (10-bit address) with Start and Stop bit interrupts enabled * I 2C Firmware Controlled Master mode, slave is Idle Selection of any I 2C mode, with the SSPEN bit set, forces the SCL and SDA pins to be open-drain, provided these pins are programmed to inputs by setting the appropriate TRISC or TRISD bits. To ensure proper operation of the module, pull-up resistors must be provided externally to the SCL and SDA pins. 17.4.3 SLAVE MODE In Slave mode, the SCL and SDA pins must be configured as inputs (TRISC<4:3> set). The MSSP module will override the input state with the output data when required (slave-transmitter). The I 2C Slave mode hardware will always generate an interrupt on an exact address match. In addition, address masking will also allow the hardware to generate an interrupt for more than one address (up to 31 in 7-bit addressing and up to 63 in 10-bit addressing). Through the mode select bits, the user can also choose to interrupt on Start and Stop bits. When an address is matched, or the data transfer after an address match is received, the hardware automatically will generate the Acknowledge (ACK) pulse and load the SSPBUF register with the received value currently in the SSPSR register. Any combination of the following conditions will cause the MSSP module not to give this ACK pulse: * The Buffer Full bit, BF (SSPSTAT<0>), was set before the transfer was received. * The overflow bit, SSPOV (SSPCON1<6>), was set before the transfer was received. In this case, the SSPSR register value is not loaded into the SSPBUF, but bit SSPIF is set. The BF bit is cleared by reading the SSPBUF register, while bit SSPOV is cleared through software. 2010 Microchip Technology Inc. The SCL clock input must have a minimum high and low for proper operation. The high and low times of the I2C specification, as well as the requirement of the MSSP module, are shown in timing parameter 100 and parameter 101. 17.4.3.1 Addressing Once the MSSP module has been enabled, it waits for a Start condition to occur. Following the Start condition, the 8 bits are shifted into the SSPSR register. All incoming bits are sampled with the rising edge of the clock (SCL) line. The value of register SSPSR<7:1> is compared to the value of the SSPADD register. The address is compared on the falling edge of the eighth clock (SCL) pulse. If the addresses match and the BF and SSPOV bits are clear, the following events occur: 1. 2. 3. 4. The SSPSR register value is loaded into the SSPBUF register. The Buffer Full bit, BF, is set. An ACK pulse is generated. The MSSP Interrupt Flag bit, SSPIF, is set (and interrupt is generated, if enabled) on the falling edge of the ninth SCL pulse. In 10-Bit Address mode, two address bytes need to be received by the slave. The five Most Significant bits (MSbs) of the first address byte specify if this is a 10-bit address. Bit, R/W (SSPSTAT<2>), must specify a write so the slave device will receive the second address byte. For a 10-bit address, the first byte would equal `11110 A9 A8 0', where `A9' and `A8' are the two MSbs of the address. The sequence of events for 10-bit address is as follows, with steps 7 through 9 for the slave-transmitter: 1. 2. 3. 4. 5. 6. 7. 8. 9. Receive the first (high) byte of address (bits, SSPIF, BF and UA (SSPSTAT<1>), are set). Update the SSPADD register with the second (low) byte of address (clears bit, UA, and releases the SCL line). Read the SSPBUF register (clears bit, BF) and clear flag bit, SSPIF. Receive second (low) byte of address (SSPIF, BF and UA bits are set). Update the SSPADD register with the first (high) byte of address. If match releases SCL line, this will clear the UA bit. Read the SSPBUF register (clears bit, BF) and clear flag bit, SSPIF. Receive Repeated Start condition. Receive first (high) byte of address (SSPIF and BF bits are set). Read the SSPBUF register (clears BF bit) and clear flag bit, SSPIF. DS39770C-page 205 PIC18F85J90 FAMILY 17.4.3.2 Address Masking Masking an address bit causes that bit to become a "don't care". When one address bit is masked, two addresses will be Acknowledged and cause an interrupt. It is possible to mask more than one address bit at a time, which makes it possible to Acknowledge up to 31 addresses in 7-bit mode and up to 63 addresses in 10-bit mode (see Example 17-2). The I2C Slave behaves the same way whether address masking is used or not. However, when address masking is used, the I2C slave can Acknowledge multiple addresses and cause interrupts. When this occurs, it is necessary to determine which address caused the interrupt by checking SSPBUF. In 7-Bit Address mode, address mask bits, ADMSK<5:1> (SSPCON<5:1>), mask the corresponding address bits in the SSPADD register. For any ADMSK bits that are set (ADMSK<n> = 1), the corresponding address bit is ignored (SSPADD<n> = x). For the module to issue an address Acknowledge, it is sufficient to match only on addresses that do not have an active address mask. EXAMPLE 17-2: In 10-Bit Address mode, the ADMSK<5:2> bits mask the corresponding address bits in the SSPADD register. In addition, ADMSK1 simultaneously masks the two LSbs of the address (SSPADD<1:0>). For any ADMSK bits that are active (ADMSK<n> = 1), the corresponding address bit is ignored (SSPADD<n> = x). Also note, that although in 10-Bit Addressing mode, the upper address bits reuse part of the SSPADD register bits. The address mask bits do not interact with those bits; they only affect the lower address bits. Note 1: ADMSK1 masks the two Least Significant bits of the address. 2: The two Most Significant bits of the address are not affected by address masking. ADDRESS MASKING EXAMPLES 7-Bit Addressing: SSPADD<7:1> = A0h (1010000) (SSPADD<0> is assumed to be `0') ADMSK<5:1> = 00111 Addresses Acknowledged: A0h, A2h, A4h, A6h, A8h, AAh, ACh, AEh 10-Bit Addressing: SSPADD<7:0> = A0h (10100000) (the two MSbs of the address are ignored in this example, since they are not affected by masking) ADMSK<5:1> = 00111 Addresses Acknowledged: A0h, A1h, A2h, A3h, A4h, A5h, A6h, A7h, A8h, A9h, AAh, ABh, ACh, ADh, AEh, AFh DS39770C-page 206 2010 Microchip Technology Inc. PIC18F85J90 FAMILY 17.4.3.3 Reception When the R/W bit of the address byte is clear and an address match occurs, the R/W bit of the SSPSTAT register is cleared. The received address is loaded into the SSPBUF register and the SDA line is held low (ACK). When the address byte overflow condition exists, then the no Acknowledge (ACK) pulse is given. An overflow condition is defined as either bit, BF (SSPSTAT<0>), is set or bit, SSPOV (SSPCON1<6>), is set. An MSSP interrupt is generated for each data transfer byte. The interrupt flag bit, SSPIF, must be cleared in software. The SSPSTAT register is used to determine the status of the byte. If SEN is enabled (SSPCON2<0> = 1), SCK/SCL will be held low (clock stretch) following each data transfer. The clock must be released by setting bit, CKP (SSPCON1<4>). See Section 17.4.4 "Clock Stretching" for more details. 17.4.3.4 Transmission When the R/W bit of the incoming address byte is set and an address match occurs, the R/W bit of the SSPSTAT register is set. The received address is loaded into the SSPBUF register. The ACK pulse will be sent on the ninth bit and pin RC3 is held low, regardless of SEN (see Section 17.4.4 "Clock Stretching" for more details). By stretching the clock, the master will be unable to assert another clock pulse until the slave is done preparing the transmit data. The transmit data must be loaded into the SSPBUF register which also loads the SSPSR register. Then, pin RC3 should be enabled by setting bit, CKP (SSPCON1<4>). The eight data bits are shifted out on the falling edge of the SCL input. This ensures that the SDA signal is valid during the SCL high time (Figure 17-10). The ACK pulse from the master-receiver is latched on the rising edge of the ninth SCL input pulse. If the SDA line is high (not ACK), then the data transfer is complete. In this case, when the ACK is latched by the slave, the slave logic is reset and the slave monitors for another occurrence of the Start bit. If the SDA line was low (ACK), the next transmit data must be loaded into the SSPBUF register. Again, pin RC3 must be enabled by setting bit, CKP. An MSSP interrupt is generated for each data transfer byte. The SSPIF bit must be cleared in software and the SSPSTAT register is used to determine the status of the byte. The SSPIF bit is set on the falling edge of the ninth clock pulse. 2010 Microchip Technology Inc. DS39770C-page 207 DS39770C-page 208 CKP 2 A6 3 A5 4 A4 5 A3 6 A2 (CKP does not reset to `0' when SEN = 0) SSPOV (SSPCON1<6>) BF (SSPSTAT<0>) SSPIF (PIR1<3>) 1 SCL S A7 7 A1 8 9 ACK R/W = 0 1 D7 3 4 D4 5 D3 Receiving Data D5 Cleared in software SSPBUF is read 2 D6 6 D2 7 D1 8 D0 9 ACK 1 D7 2 D6 3 4 D4 5 D3 Receiving Data D5 6 D2 7 D1 8 D0 Bus master terminates transfer P SSPOV is set because SSPBUF is still full. ACK is not sent. 9 ACK FIGURE 17-8: SDA Receiving Address PIC18F85J90 FAMILY I2CTM SLAVE MODE TIMING WITH SEN = 0 (RECEPTION, 7-BIT ADDRESS) 2010 Microchip Technology Inc. 2010 Microchip Technology Inc. Note CKP 2 A6 3 4 X 5 A3 Receiving Address A5 6 X 1 3 4 D4 5 D3 Receiving Data D5 Cleared in software SSPBUF is read 2 D6 6 D2 7 D1 8 D0 In this example, an address equal to A7.A6.A5.X.A3.X.X will be Acknowledged and cause an interrupt. 9 D7 x = Don't care (i.e., address bit can be either a `1' or a `0'). 8 ACK R/W = 0 2: 7 X 1: (CKP does not reset to `0' when SEN = 0) SSPOV (SSPCON1<6>) BF (SSPSTAT<0>) SSPIF (PIR1<3>) 1 SCL S A7 9 ACK 1 D7 2 D6 3 4 D4 5 D3 Receiving Data D5 6 D2 7 D1 8 D0 Bus master terminates transfer P SSPOV is set because SSPBUF is still full. ACK is not sent. 9 ACK FIGURE 17-9: SDA PIC18F85J90 FAMILY I2CTM SLAVE MODE TIMING WITH SEN = 0 AND ADMSK<5:1> = 01011 (RECEPTION, 7-BIT ADDRESS) DS39770C-page 209 DS39770C-page 210 2 Data in sampled 1 A6 CKP (SSPxCON1<4>) BF (SSPxSTAT<0>) SSPxIF (PIR1<3> or PIR3<7>) S A7 3 4 A4 5 A3 6 A2 Receiving Address A5 7 A1 8 R/W = 1 9 ACK 3 D5 4 5 D3 SSPxBUF is written in software 6 D2 Transmitting Data D4 Cleared in software 2 D6 CKP is set in software Clear by reading SCLx held low while CPU responds to SSPxIF 1 D7 7 8 D0 9 From SSPxIF ISR D1 ACK 1 D7 4 D4 5 D3 Cleared in software 3 D5 6 D2 CKP is set in software SSPxBUF is written in software 2 D6 7 8 D0 9 ACK From SSPxIF ISR D1 Transmitting Data P FIGURE 17-10: SCLx SDAx PIC18F85J90 FAMILY I2CTM SLAVE MODE TIMING (TRANSMISSION, 7-BIT ADDRESS) 2010 Microchip Technology Inc. 2010 Microchip Technology Inc. 4 1 5 0 7 A8 UA is set indicating that the SSPADD needs to be updated SSPBUF is written with contents of SSPSR 6 A9 8 9 (CKP does not reset to `0' when SEN = 0) UA (SSPSTAT<1>) CKP 3 1 Cleared in software 2 1 SSPOV (SSPCON1<6>) BF (SSPSTAT<0>) SSPIF (PIR1<3>) 1 SCL S 1 ACK R/W = 0 A7 2 4 A4 5 A3 6 A2 8 A0 UA is set indicating that SSPADD needs to be updated Cleared by hardware when SSPADD is updated with low byte of address 7 A1 Cleared in software 3 A5 Dummy read of SSPBUF to clear BF flag 1 A6 Receive Second Byte of Address 9 ACK 1 D7 4 5 6 Cleared in software 3 7 D5 D4 D3 D2 D1 Receive Data Byte Cleared by hardware when SSPADD is updated with high byte of address 2 D6 Clock is held low until update of SSPADD has taken place 8 9 1 2 4 5 6 D3 D2 Cleared in software 3 D5 D4 Receive Data Byte D0 ACK D7 D6 7 8 D1 D0 9 P Bus master terminates transfer SSPOV is set because SSPBUF is still full. ACK is not sent. ACK FIGURE 17-11: SDA Receive First Byte of Address Clock is held low until update of SSPADD has taken place PIC18F85J90 FAMILY I2CTM SLAVE MODE TIMING WITH SEN = 0 (RECEPTION, 10-BIT ADDRESS) DS39770C-page 211 DS39770C-page 212 2 1 Note 4 1 5 0 7 A8 UA is set indicating that the SSPADD needs to be updated SSPBUF is written with contents of SSPSR 6 A9 8 9 ACK 2 X 4 5 A3 6 A2 Cleared in software 3 A5 4 5 6 7 8 9 1 2 4 5 6 D3 D2 Cleared in software 3 D5 D4 Receive Data Byte D1 D0 ACK D7 D6 Cleared in software 3 D2 Cleared by hardware when SSPADD is updated with high byte of address 2 D6 D5 D4 D3 Note that the Most Significant bits of the address are not affected by the bit masking. 1 D7 3: 9 ACK x = Don't care (i.e., address bit can be either a `1' or a `0'). 8 X In this example, an address equal to A9.A8.A7.A6.A5.X.A3.A2.X.X will be Acknowledged and cause an interrupt. UA is set indicating that SSPADD needs to be updated 7 X Cleared by hardware when SSPADD is updated with low byte of address Dummy read of SSPBUF to clear BF flag 1 A6 Receive Data Byte 2: A7 Receive Second Byte of Address 1: (CKP does not reset to `0' when SEN = 0) UA (SSPSTAT<1>) SSPOV (SSPCON1<6>) CKP 3 1 Cleared in software BF (SSPSTAT<0>) SSPIF (PIR1<3>) 1 SCL S 1 R/W = 0 Clock is held low until update of SSPADD has taken place 7 8 D1 D0 9 P Bus master terminates transfer SSPOV is set because SSPBUF is still full. ACK is not sent. ACK FIGURE 17-12: SDA Receive First Byte of Address Clock is held low until update of SSPADD has taken place PIC18F85J90 FAMILY I2CTM SLAVE MODE TIMING WITH SEN = 0 AND ADMSK<5:1> = 01001 (RECEPTION, 10-BIT ADDRESS) 2010 Microchip Technology Inc. 2010 Microchip Technology Inc. 2 1 CKP (SSPCON1<4>) UA (SSPSTAT<1>) BF (SSPSTAT<0>) SSPIF (PIR1<3>) 1 SCL S 1 4 1 5 0 6 7 A9 A8 8 UA is set indicating that the SSPADD needs to be updated SSPBUF is written with contents of SSPSR 3 1 9 ACK R/W = 0 1 3 4 5 Cleared in software 2 7 UA is set indicating that SSPADD needs to be updated Cleared by hardware when SSPADD is updated with low byte of address 6 8 A6 A5 A4 A3 A2 A1 A0 Receive Second Byte of Address Dummy read of SSPBUF to clear BF flag A7 9 ACK 2 3 1 4 1 Cleared in software 1 1 5 0 6 8 9 ACK R/W = 1 1 2 4 5 6 Cleared in software 3 CKP is set in software 9 P Completion of data transmission clears BF flag 8 ACK Bus master terminates transfer CKP is automatically cleared in hardware, holding SCL low 7 D7 D6 D5 D4 D3 D2 D1 D0 Transmitting Data Byte Clock is held low until CKP is set to `1' Write of SSPBUF BF flag is clear initiates transmit at the end of the third address sequence 7 A9 A8 Cleared by hardware when SSPADD is updated with high byte of address. Dummy read of SSPBUF to clear BF flag Sr 1 Receive First Byte of Address Clock is held low until update of SSPADD has taken place FIGURE 17-13: SDA Receive First Byte of Address Clock is held low until update of SSPADD has taken place PIC18F85J90 FAMILY I2CTM SLAVE MODE TIMING (TRANSMISSION, 10-BIT ADDRESS) DS39770C-page 213 PIC18F85J90 FAMILY 17.4.4 CLOCK STRETCHING Both 7-Bit and 10-Bit Slave modes implement automatic clock stretching during a transmit sequence. The SEN bit (SSPCON2<0>) allows clock stretching to be enabled during receives. Setting SEN will cause the SCL pin to be held low at the end of each data receive sequence. 17.4.4.1 Clock Stretching for 7-Bit Slave Receive Mode (SEN = 1) In 7-Bit Slave Receive mode, on the falling edge of the ninth clock at the end of the ACK sequence, if the BF bit is set, the CKP bit in the SSPCON1 register is automatically cleared, forcing the SCL output to be held low. The CKP being cleared to `0' will assert the SCL line low. The CKP bit must be set in the user's ISR before reception is allowed to continue. By holding the SCL line low, the user has time to service the ISR and read the contents of the SSPBUF before the master device can initiate another receive sequence. This will prevent buffer overruns from occurring (see Figure 17-15). Note 1: If the user reads the contents of the SSPBUF before the falling edge of the ninth clock, thus clearing the BF bit, the CKP bit will not be cleared and clock stretching will not occur. 2: The CKP bit can be set in software regardless of the state of the BF bit. The user should be careful to clear the BF bit in the ISR before the next receive sequence in order to prevent an overflow condition. 17.4.4.2 17.4.4.3 Clock Stretching for 7-Bit Slave Transmit Mode The 7-Bit Slave Transmit mode implements clock stretching by clearing the CKP bit after the falling edge of the ninth clock if the BF bit is clear. This occurs regardless of the state of the SEN bit. The user's ISR must set the CKP bit before transmission is allowed to continue. By holding the SCL line low, the user has time to service the ISR and load the contents of the SSPBUF before the master device can initiate another transmit sequence (see Figure 17-10). Note 1: If the user loads the contents of SSPBUF, setting the BF bit before the falling edge of the ninth clock, the CKP bit will not be cleared and clock stretching will not occur. 2: The CKP bit can be set in software regardless of the state of the BF bit. 17.4.4.4 Clock Stretching for 10-Bit Slave Transmit Mode In 10-Bit Slave Transmit mode, clock stretching is controlled during the first two address sequences by the state of the UA bit, just as it is in 10-Bit Slave Receive mode. The first two addresses are followed by a third address sequence which contains the high-order bits of the 10-bit address and the R/W bit set to `1'. After the third address sequence is performed, the UA bit is not set, the module is now configured in Transmit mode and clock stretching is controlled by the BF flag as in 7-Bit Slave Transmit mode (see Figure 17-13). Clock Stretching for 10-Bit Slave Receive Mode (SEN = 1) In 10-Bit Slave Receive mode, during the address sequence, clock stretching automatically takes place but CKP is not cleared. During this time, if the UA bit is set after the ninth clock, clock stretching is initiated. The UA bit is set after receiving the upper byte of the 10-bit address and following the receive of the second byte of the 10-bit address with the R/W bit cleared to `0'. The release of the clock line occurs upon updating SSPADD. Clock stretching will occur on each data receive sequence as described in 7-bit mode. Note: If the user polls the UA bit and clears it by updating the SSPADD register before the falling edge of the ninth clock occurs and if the user hasn't cleared the BF bit by reading the SSPBUF register before that time, then the CKP bit will still NOT be asserted low. Clock stretching on the basis of the state of the BF bit only occurs during a data sequence, not an address sequence. DS39770C-page 214 2010 Microchip Technology Inc. PIC18F85J90 FAMILY 17.4.4.5 Clock Synchronization and the CKP bit When the CKP bit is cleared, the SCL output is forced to `0'. However, clearing the CKP bit will not assert the SCL output low until the SCL output is already sampled low. Therefore, the CKP bit will not assert the SCL line until an external I2C master device has FIGURE 17-14: already asserted the SCL line. The SCL output will remain low until the CKP bit is set and all other devices on the I2C bus have deasserted SCL. This ensures that a write to the CKP bit will not violate the minimum high time requirement for SCL (see Figure 17-14). CLOCK SYNCHRONIZATION TIMING Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 SDA DX DX - 1 SCL CKP Master device asserts clock Master device deasserts clock WR SSPCON 2010 Microchip Technology Inc. DS39770C-page 215 DS39770C-page 216 CKP SSPOV (SSPCON1<6>) BF (SSPSTAT<0>) SSPIF (PIR1<3>) 1 SCL S A7 2 A6 3 4 A4 5 A3 6 A2 Receiving Address A5 7 A1 8 9 ACK R/W = 0 3 4 D4 5 D3 Receiving Data D5 Cleared in software 2 D6 If BF is cleared prior to the falling edge of the 9th clock, CKP will not be reset to `0' and no clock stretching will occur SSPBUF is read 1 D7 6 D2 7 D1 9 ACK 1 D7 BF is set after falling edge of the 9th clock, CKP is reset to `0' and clock stretching occurs 8 D0 3 4 D4 5 D3 Receiving Data D5 CKP written to `1' in software 2 D6 Clock is held low until CKP is set to `1' 6 D2 7 D1 8 D0 Bus master terminates transfer P SSPOV is set because SSPBUF is still full. ACK is not sent. 9 ACK Clock is not held low because ACK = 1 FIGURE 17-15: SDA Clock is not held low because buffer full bit is clear prior to falling edge of 9th clock PIC18F85J90 FAMILY I2CTM SLAVE MODE TIMING WITH SEN = 1 (RECEPTION, 7-BIT ADDRESS) 2010 Microchip Technology Inc. 2010 Microchip Technology Inc. 2 1 UA (SSPSTAT<1>) SSPOV (SSPCON1<6>) CKP 3 1 4 1 5 0 6 7 A9 A8 8 UA is set indicating that the SSPADD needs to be updated SSPBUF is written with contents of SSPSR Cleared in software BF (SSPSTAT<0>) SSPIF (PIR1<3>) 1 SCL S 1 9 ACK R/W = 0 A7 2 4 A4 5 A3 6 A2 Cleared in software 3 A5 7 A1 8 A0 Note: An update of the SSPADD register before the falling edge of the ninth clock will have no effect on UA and UA will remain set. UA is set indicating that SSPADD needs to be updated Cleared by hardware when SSPADD is updated with low byte of address after falling edge of ninth clock Dummy read of SSPBUF to clear BF flag 1 A6 Receive Second Byte of Address 9 ACK 2 4 5 6 Cleared in software 3 D3 D2 7 8 1 4 5 6 Cleared in software 3 CKP written to `1' in software 2 D3 D2 Receive Data Byte D7 D6 D5 D4 Note: An update of the SSPADD register before the falling edge of the ninth clock will have no effect on UA and UA will remain set. 9 ACK Clock is held low until CKP is set to `1' D1 D0 Cleared by hardware when SSPADD is updated with high byte of address after falling edge of ninth clock Dummy read of SSPBUF to clear BF flag 1 D7 D6 D5 D4 Receive Data Byte Clock is held low until update of SSPADD has taken place 7 8 9 ACK Bus master terminates transfer P SSPOV is set because SSPBUF is still full. ACK is not sent. D1 D0 Clock is not held low because ACK = 1 FIGURE 17-16: SDA Receive First Byte of Address Clock is held low until update of SSPADD has taken place PIC18F85J90 FAMILY I2CTM SLAVE MODE TIMING WITH SEN = 1 (RECEPTION, 10-BIT ADDRESS) DS39770C-page 217 PIC18F85J90 FAMILY 17.4.5 GENERAL CALL ADDRESS SUPPORT If the general call address matches, the SSPSR is transferred to the SSPBUF, the BF flag bit is set (eighth bit) and on the falling edge of the ninth bit (ACK bit), the SSPIF interrupt flag bit is set. The addressing procedure for the I2C bus is such that the first byte after the Start condition usually determines which device will be the slave addressed by the master. The exception is the general call address which can address all devices. When this address is used, all devices should, in theory, respond with an Acknowledge. When the interrupt is serviced, the source for the interrupt can be checked by reading the contents of the SSPBUF. The value can be used to determine if the address was device-specific or a general call address. In 10-bit mode, the SSPADD is required to be updated for the second half of the address to match and the UA bit is set (SSPSTAT<1>). If the general call address is sampled when the GCEN bit is set, while the slave is configured in 10-Bit Address mode, then the second half of the address is not necessary, the UA bit will not be set and the slave will begin receiving data after the Acknowledge (Figure 17-17). The general call address is one of eight addresses reserved for specific purposes by the I2C protocol. It consists of all `0's with R/W = 0. The general call address is recognized when the General Call Enable bit, GCEN, is enabled (SSPCON2<7> set). Following a Start bit detect, 8 bits are shifted into the SSPSR and the address is compared against the SSPADD. It is also compared to the general call address and fixed in hardware. FIGURE 17-17: SLAVE MODE GENERAL CALL ADDRESS SEQUENCE (7 OR 10-BIT ADDRESS MODE) Address is compared to General Call Address after ACK, set interrupt SCL S 1 2 3 4 5 Receiving Data R/W = 0 General Call Address SDA ACK D7 6 7 8 9 1 ACK D6 D5 D4 D3 D2 D1 D0 2 3 4 5 6 7 8 9 SSPIF BF (SSPSTAT<0>) Cleared in software SSPBUF is read SSPOV (SSPCON1<6>) `0' GCEN (SSPCON2<7>) `1' DS39770C-page 218 2010 Microchip Technology Inc. PIC18F85J90 FAMILY MASTER MODE Note: The MSSP module, when configured in I2C Master mode, does not allow queueing of events. For instance, the user is not allowed to initiate a Start condition and immediately write the SSPBUF register to initiate transmission before the Start condition is complete. In this case, the SSPBUF will not be written to and the WCOL bit will be set, indicating that a write to the SSPBUF did not occur. Master mode is enabled by setting and clearing the appropriate SSPM bits in SSPCON1 and by setting the SSPEN bit. In Master mode, the SCL and SDA lines are manipulated by the MSSP hardware. Master mode of operation is supported by interrupt generation on the detection of the Start and Stop conditions. The Stop (P) and Start (S) bits are cleared from a Reset or when the MSSP module is disabled. Control of the I 2C bus may be taken when the P bit is set, or the bus is Idle, with both the S and P bits clear. The following events will cause the MSSP Interrupt Flag bit, SSPIF, to be set (and MSSP interrupt, if enabled): In Firmware Controlled Master mode, user code conducts all I 2C bus operations based on Start and Stop bit conditions. * * * * * Once Master mode is enabled, the user has six options. 1. 2. 3. 4. 5. 6. Assert a Start condition on SDA and SCL. Assert a Repeated Start condition on SDA and SCL. Write to the SSPBUF register initiating transmission of data/address. Configure the I2C port to receive data. Generate an Acknowledge condition at the end of a received byte of data. Generate a Stop condition on SDA and SCL. FIGURE 17-18: Start condition Stop condition Data transfer byte transmitted/received Acknowledge transmit Repeated Start MSSP BLOCK DIAGRAM (I2CTM MASTER MODE) Internal Data Bus Read SSPM<3:0> SSPADD<6:0> Write SSPBUF SDA Baud Rate Generator Shift Clock SDA In SCL In Bus Collision 2010 Microchip Technology Inc. LSb Start bit, Stop bit, Acknowledge Generate Start bit Detect Stop bit Detect Write Collision Detect Clock Arbitration State Counter for End of XMIT/RCV Clock Cntl SCL Receive Enable SSPSR MSb Clock Arbitrate/WCOL Detect (hold off clock source) 17.4.6 Set/Reset S, P, WCOL (SSPSTAT, SSPCON1) Set SSPIF, BCLIF Reset ACKSTAT, PEN (SSPCON2) DS39770C-page 219 PIC18F85J90 FAMILY 17.4.6.1 I2C Master Mode Operation The master device generates all of the serial clock pulses and the Start and Stop conditions. A transfer is ended with a Stop condition or with a Repeated Start condition. Since the Repeated Start condition is also the beginning of the next serial transfer, the I2C bus will not be released. In Master Transmitter mode, serial data is output through SDA, while SCL outputs the serial clock. The first byte transmitted contains the slave address of the receiving device (7 bits) and the Read/Write (R/W) bit. In this case, the R/W bit will be logic `0'. Serial data is transmitted 8 bits at a time. After each byte is transmitted, an Acknowledge bit is received. Start and Stop conditions are output to indicate the beginning and the end of a serial transfer. In Master Receive mode, the first byte transmitted contains the slave address of the transmitting device (7 bits) and the R/W bit. In this case, the R/W bit will be logic `1'. Thus, the first byte transmitted is a 7-bit slave address followed by a `1' to indicate the receive bit. Serial data is received via SDA, while SCL outputs the serial clock. Serial data is received 8 bits at a time. After each byte is received, an Acknowledge bit is transmitted. Start and Stop conditions indicate the beginning and end of transmission. The Baud Rate Generator used for the SPI mode operation is used to set the SCL clock frequency for either 100 kHz, 400 kHz or 1 MHz I2C operation. See Section 17.4.7 "Baud Rate" for more details. DS39770C-page 220 A typical transmit sequence would go as follows: 1. The user generates a Start condition by setting the Start Enable bit, SEN (SSPCON2<0>). 2. SSPIF is set. The MSSP module will wait the required start time before any other operation takes place. 3. The user loads the SSPBUF with the slave address to transmit. 4. The address is shifted out of the SDA pin until all 8 bits are transmitted. 5. The MSSP module shifts in the ACK bit from the slave device and writes its value into the SSPCON2 register (SSPCON2<6>). 6. The MSSP module generates an interrupt at the end of the ninth clock cycle by setting the SSPIF bit. 7. The user loads the SSPBUF with eight bits of data. 8. Data is shifted out of the SDA pin until all 8 bits are transmitted. 9. The MSSP module shifts in the ACK bit from the slave device and writes its value into the SSPCON2 register (SSPCON2<6>). 10. The MSSP module generates an interrupt at the end of the ninth clock cycle by setting the SSPIF bit. 11. The user generates a Stop condition by setting the Stop Enable bit, PEN (SSPCON2<2>). 12. The interrupt is generated once the Stop condition is complete. 2010 Microchip Technology Inc. PIC18F85J90 FAMILY 17.4.7 BAUD RATE 2 In I C Master mode, the Baud Rate Generator (BRG) reload value is placed in the lower 7 bits of the SSPADD register (Figure 17-19). When a write occurs to SSPBUF, the Baud Rate Generator will automatically begin counting. The BRG counts down to 0 and stops until another reload has taken place. The BRG count is decremented twice per instruction cycle (TCY) on the Q2 and Q4 clocks. In I2C Master mode, the BRG is reloaded automatically. Once the given operation is complete (i.e., transmission of the last data bit is followed by ACK), the internal clock will automatically stop counting and the SCL pin will remain in its last state. FIGURE 17-19: Table 17-3 demonstrates clock rates based on instruction cycles and the BRG value loaded into SSPADD. The SSPADD BRG value of 0x00 is not supported 17.4.7.1 When the device is operating in one of the power-managed modes, the clock source to the BRG may change frequency or even stop, depending on the mode and clock source selected. Switching to a Run or Idle mode from either the secondary clock or internal oscillator is likely to change the clock rate to the BRG. In Sleep mode, the BRG will not be clocked at all. BAUD RATE GENERATOR BLOCK DIAGRAM SSPM<3:0> SSPM<3:0> Reload SCL Control CLKO SSPADD<6:0> Reload BRG Down Counter FOSC/4 I2CTM CLOCK RATE w/BRG TABLE 17-3: Note 1: Baud Rate Generation in Power-Managed Modes FCY FCY * 2 BRG Value FSCL (2 Rollovers of BRG) 10 MHz 20 MHz 18h 400 kHz(1) 10 MHz 20 MHz 1Fh 312.5 kHz 10 MHz 20 MHz 63h 100 kHz 4 MHz 8 MHz 09h 400 kHz(1) 4 MHz 8 MHz 0Ch 308 kHz 4 MHz 8 MHz 27h 100 kHz 1 MHz 2 MHz 02h 333 kHz(1) 1 MHz 2 MHz 09h 100 kHz 2C I2C specification (which applies to rates greater than The I interface does not conform to the 400 kHz 100 kHz) in all details, but may be used with care where higher rates are required by the application. 2010 Microchip Technology Inc. DS39770C-page 221 PIC18F85J90 FAMILY 17.4.7.2 Clock Arbitration Clock arbitration occurs when the master, during any receive, transmit or Repeated Start/Stop condition, deasserts the SCL pin (SCL allowed to float high). When the SCL pin is allowed to float high, the Baud Rate Generator (BRG) is suspended from counting until the SCL pin is actually sampled high. When the FIGURE 17-20: SDA SCL pin is sampled high, the Baud Rate Generator is reloaded with the contents of SSPADD<6:0> and begins counting. This ensures that the SCL high time will always be at least one BRG rollover count in the event that the clock is held low by an external device (Figure 17-20). BAUD RATE GENERATOR TIMING WITH CLOCK ARBITRATION DX DX - 1 SCL deasserted but slave holds SCL low (clock arbitration) SCL allowed to transition high SCL BRG decrements on Q2 and Q4 cycles BRG Value 03h 02h 01h 00h (hold off) 03h 02h SCL is sampled high, reload takes place and BRG starts its count BRG Reload DS39770C-page 222 2010 Microchip Technology Inc. PIC18F85J90 FAMILY 17.4.8 I2C MASTER MODE START CONDITION TIMING Note: To initiate a Start condition, the user sets the Start Enable bit, SEN (SSPCON2<0>). If the SDA and SCL pins are sampled high, the Baud Rate Generator is reloaded with the contents of SSPADD<6:0> and starts its count. If SCL and SDA are both sampled high when the Baud Rate Generator times out (TBRG), the SDA pin is driven low. The action of the SDA being driven low while SCL is high is the Start condition and causes the S bit (SSPSTAT<3>) to be set. Following this, the Baud Rate Generator is reloaded with the contents of SSPADD<6:0> and resumes its count. When the Baud Rate Generator times out (TBRG), the SEN bit (SSPCON2<0>) will be automatically cleared by hardware. The Baud Rate Generator is suspended, leaving the SDA line held low and the Start condition is complete. FIGURE 17-21: 17.4.8.1 If, at the beginning of the Start condition, the SDA and SCL pins are already sampled low, or if during the Start condition, the SCL line is sampled low before the SDA line is driven low, a bus collision occurs. The Bus Collision Interrupt Flag, BCLIF, is set, the Start condition is aborted and the I2C module is reset into its Idle state. WCOL Status Flag If the user writes the SSPBUF when a Start sequence is in progress, the WCOL is set and the contents of the buffer are unchanged (the write doesn't occur). Note: Because queueing of events is not allowed, writing to the lower 5 bits of SSPCON2 is disabled until the Start condition is complete. FIRST START BIT TIMING Write to SEN bit occurs here Set S bit (SSPSTAT<3>) SDA = 1, SCL = 1 TBRG At completion of Start bit, hardware clears SEN bit and sets SSPIF bit TBRG Write to SSPBUF occurs here 1st bit SDA 2nd bit TBRG SCL TBRG S 2010 Microchip Technology Inc. DS39770C-page 223 PIC18F85J90 FAMILY 17.4.9 I2C MASTER MODE REPEATED START CONDITION TIMING Note 1: If RSEN is programmed while any other event is in progress, it will not take effect. A Repeated Start condition occurs when the RSEN bit (SSPCON2<1>) is programmed high and the I2C logic module is in the Idle state. When the RSEN bit is set, the SCL pin is asserted low. When the SCL pin is sampled low, the Baud Rate Generator is loaded with the contents of SSPADD<6:0> and begins counting. The SDA pin is released (brought high) for one Baud Rate Generator count (TBRG). When the Baud Rate Generator times out, if SDA is sampled high, the SCL pin will be deasserted (brought high). When SCL is sampled high, the Baud Rate Generator is reloaded with the contents of SSPADD<6:0> and begins counting. SDA and SCL must be sampled high for one TBRG. This action is then followed by assertion of the SDA pin (SDA = 0) for one TBRG while SCL is high. Following this, the RSEN bit (SSPCON2<1>) will be automatically cleared and the Baud Rate Generator will not be reloaded, leaving the SDA pin held low. As soon as a Start condition is detected on the SDA and SCL pins, the S bit (SSPSTAT<3>) will be set. The SSPIF bit will not be set until the Baud Rate Generator has timed out. 2: A bus collision during the Repeated Start condition occurs if: * SDA is sampled low when SCL goes from low-to-high. * SCL goes low before SDA is asserted low. This may indicate that another master is attempting to transmit a data `1'. Immediately following the SSPIF bit getting set, the user may write the SSPBUF with the 7-bit address in 7-bit mode or the default first address in 10-bit mode. After the first eight bits are transmitted and an ACK is received, the user may then transmit an additional eight bits of address (10-bit mode) or eight bits of data (7-bit mode). 17.4.9.1 If the user writes the SSPBUF when a Repeated Start sequence is in progress, the WCOL is set and the contents of the buffer are unchanged (the write doesn't occur). Note: FIGURE 17-22: WCOL Status Flag Because queueing of events is not allowed, writing of the lower 5 bits of SSPCON2 is disabled until the Repeated Start condition is complete. REPEATED START CONDITION WAVEFORM S bit set by hardware Write to SSPCON2 occurs here: SDA = 1, SCL (no change) SDA = 1, SCL = 1 TBRG TBRG At completion of Start bit, hardware clears RSEN bit and sets SSPIF TBRG 1st bit SDA RSEN bit set by hardware on falling edge of ninth clock, end of Xmit Write to SSPBUF occurs here TBRG SCL TBRG Sr = Repeated Start DS39770C-page 224 2010 Microchip Technology Inc. PIC18F85J90 FAMILY 17.4.10 I2C MASTER MODE TRANSMISSION Transmission of a data byte, a 7-bit address or the other half of a 10-bit address is accomplished by simply writing a value to the SSPBUF register. This action will set the Buffer Full bit, BF, and allow the Baud Rate Generator to begin counting and start the next transmission. Each bit of address/data will be shifted out onto the SDA pin after the falling edge of SCL is asserted (see data hold time specification parameter 106). SCL is held low for one Baud Rate Generator rollover count (TBRG). Data should be valid before SCL is released high (see data setup time specification parameter 107). When the SCL pin is released high, it is held that way for TBRG. The data on the SDA pin must remain stable for that duration and some hold time after the next falling edge of SCL. After the eighth bit is shifted out (the falling edge of the eighth clock), the BF flag is cleared and the master releases SDA. This allows the slave device being addressed to respond with an ACK bit during the ninth bit time if an address match occurred, or if data was received properly. The status of ACK is written into the ACKDT bit on the falling edge of the ninth clock. If the master receives an Acknowledge, the Acknowledge Status bit, ACKSTAT, is cleared; if not, the bit is set. After the ninth clock, the SSPIF bit is set and the master clock (Baud Rate Generator) is suspended until the next data byte is loaded into the SSPBUF, leaving SCL low and SDA unchanged (Figure 17-23). After the write to the SSPBUF, each bit of the address will be shifted out on the falling edge of SCL until all seven address bits and the R/W bit are completed. On the falling edge of the eighth clock, the master will deassert the SDA pin, allowing the slave to respond with an Acknowledge. On the falling edge of the ninth clock, the master will sample the SDA pin to see if the address was recognized by a slave. The status of the ACK bit is loaded into the ACKSTAT status bit (SSPCON2<6>). Following the falling edge of the ninth clock transmission of the address, the SSPIF is set, the BF flag is cleared and the Baud Rate Generator is turned off until another write to the SSPBUF takes place, holding SCL low and allowing SDA to float. 17.4.10.1 BF Status Flag In Transmit mode, the BF bit (SSPSTAT<0>) is set when the CPU writes to SSPBUF and is cleared when all 8 bits are shifted out. 17.4.10.2 The user should verify that the WCOL is clear after each write to SSPBUF to ensure the transfer is correct. In all cases, WCOL must be cleared in software. 17.4.10.3 ACKSTAT Status Flag In Transmit mode, the ACKSTAT bit (SSPCON2<6>) is cleared when the slave has sent an Acknowledge (ACK = 0) and is set when the slave does not Acknowledge (ACK = 1). A slave sends an Acknowledge when it has recognized its address (including a general call), or when the slave has properly received its data. 17.4.11 I2C MASTER MODE RECEPTION Master mode reception is enabled by programming the Receive Enable bit, RCEN (SSPCON2<3>). Note: The MSSP module must be in an Idle state before the RCEN bit is set or the RCEN bit will be disregarded. The Baud Rate Generator begins counting and on each rollover, the state of the SCL pin changes (high-to-low/low-to-high) and data is shifted into the SSPSR. After the falling edge of the eighth clock, the receive enable flag is automatically cleared, the contents of the SSPSR are loaded into the SSPBUF, the BF flag bit is set, the SSPIF flag bit is set and the Baud Rate Generator is suspended from counting, holding SCL low. The MSSP is now in Idle state awaiting the next command. When the buffer is read by the CPU, the BF flag bit is automatically cleared. The user can then send an Acknowledge bit at the end of reception by setting the Acknowledge Sequence Enable bit, ACKEN (SSPCON2<4>). 17.4.11.1 BF Status Flag In receive operation, the BF bit is set when an address or data byte is loaded into SSPBUF from SSPSR. It is cleared when the SSPBUF register is read. 17.4.11.2 SSPOV Status Flag In receive operation, the SSPOV bit is set when 8 bits are received into the SSPSR and the BF flag bit is already set from a previous reception. 17.4.11.3 WCOL Status Flag If the user writes the SSPBUF when a receive is already in progress (i.e., SSPSR is still shifting in a data byte), the WCOL bit is set and the contents of the buffer are unchanged (the write doesn't occur). WCOL Status Flag If the user writes to the SSPBUF when a transmit is already in progress (i.e., SSPSR is still shifting out a data byte), the WCOL is set and the contents of the buffer are unchanged (the write doesn't occur) after 2 TCY after the SSPBUF write. If SSPBUF is rewritten within 2 TCY, the WCOL bit is set and SSPBUF is updated. This may result in a corrupted transfer. 2010 Microchip Technology Inc. DS39770C-page 225 DS39770C-page 226 S R/W PEN SEN BF (SSPSTAT<0>) SSPIF SCL SDA A6 A5 A4 A3 A2 A1 3 4 5 Cleared in software 2 6 7 8 9 After Start condition, SEN cleared by hardware SSPBUF written 1 D7 1 SCL held low while CPU responds to SSPIF ACK = 0 R/W = 0 SSPBUF written with 7-bit address and R/W start transmit A7 Transmit Address to Slave 3 D5 4 D4 5 D3 6 D2 7 D1 8 D0 SSPBUF is written in software Cleared in software service routine from MSSP interrupt 2 D6 Transmitting Data or Second Half of 10-bit Address P Cleared in software 9 ACK From slave, clear ACKSTAT bit (SSPCON2<6>) ACKSTAT in SSPCON2 = 1 FIGURE 17-23: SEN = 0 Write SSPCON2<0> (SEN = 1), Start condition begins PIC18F85J90 FAMILY I 2CTM MASTER MODE WAVEFORM (TRANSMISSION, 7 OR 10-BIT ADDRESS) 2010 Microchip Technology Inc. 2010 Microchip Technology Inc. S ACKEN SSPOV BF (SSPSTAT<0>) SDA = 0, SCL = 1 while CPU responds to SSPIF SSPIF SCL SDA Transmit Address to Slave 1 2 4 5 6 Cleared in software 3 7 A7 A6 A5 A4 A3 A2 A1 8 9 R/W = 1 ACK ACK from Slave 2 3 5 6 7 8 D0 9 ACK 2 3 4 5 6 7 Cleared in software Set SSPIF interrupt at end of Acknowledge sequence Data shifted in on falling edge of CLK 1 D7 D6 D5 D4 D3 D2 D1 Cleared in software Set SSPIF at end of receive 9 ACK is not sent ACK Bus master terminates transfer Set P bit (SSPSTAT<4>) and SSPIF Set SSPIF interrupt at end of Acknowledge sequence P PEN bit = 1 written here SSPOV is set because SSPBUF is still full 8 D0 RCEN cleared automatically Set ACKEN, start Acknowledge sequence, SDA = ACKDT = 1 Receiving Data from Slave RCEN = 1, start next receive ACK from Master, SDA = ACKDT = 0 Last bit is shifted into SSPSR and contents are unloaded into SSPBUF Cleared in software Set SSPIF interrupt at end of receive 4 Cleared in software 1 D7 D6 D5 D4 D3 D2 D1 Receiving Data from Slave RCEN cleared automatically Master configured as a receiver by programming SSPCON2<3> (RCEN = 1) FIGURE 17-24: SEN = 0 Write to SSPBUF occurs here, start XMIT Write to SSPCON2<0> (SEN = 1), begin Start condition Write to SSPCON2<4> to start Acknowledge sequence, SDA = ACKDT (SSPCON2<5>) = 0 PIC18F85J90 FAMILY I 2CTM MASTER MODE WAVEFORM (RECEPTION, 7-BIT ADDRESS) DS39770C-page 227 PIC18F85J90 FAMILY 17.4.12 ACKNOWLEDGE SEQUENCE TIMING 17.4.13 A Stop bit is asserted on the SDA pin at the end of a receive/transmit by setting the Stop Sequence Enable bit, PEN (SSPCON2<2>). At the end of a receive/transmit, the SCL line is held low after the falling edge of the ninth clock. When the PEN bit is set, the master will assert the SDA line low. When the SDA line is sampled low, the Baud Rate Generator is reloaded and counts down to 0. When the Baud Rate Generator times out, the SCL pin will be brought high and one TBRG (Baud Rate Generator rollover count) later, the SDA pin will be deasserted. When the SDA pin is sampled high while SCL is high, the P bit (SSPSTAT<4>) is set. A TBRG later, the PEN bit is cleared and the SSPIF bit is set (Figure 17-26). An Acknowledge sequence is enabled by setting the Acknowledge Sequence Enable bit, ACKEN (SSPCON2<4>). When this bit is set, the SCL pin is pulled low and the contents of the Acknowledge data bit are presented on the SDA pin. If the user wishes to generate an Acknowledge, then the ACKDT bit should be cleared. If not, the user should set the ACKDT bit before starting an Acknowledge sequence. The Baud Rate Generator then counts for one rollover period (TBRG) and the SCL pin is deasserted (pulled high). When the SCL pin is sampled high (clock arbitration), the Baud Rate Generator counts for TBRG. The SCL pin is then pulled low. Following this, the ACKEN bit is automatically cleared, the Baud Rate Generator is turned off and the MSSP module then goes into Idle mode (Figure 17-25). 17.4.12.1 17.4.13.1 WCOL Status Flag If the user writes the SSPBUF when a Stop sequence is in progress, then the WCOL bit is set and the contents of the buffer are unchanged (the write doesn't occur). WCOL Status Flag If the user writes the SSPBUF when an Acknowledge sequence is in progress, then WCOL is set and the contents of the buffer are unchanged (the write doesn't occur). FIGURE 17-25: STOP CONDITION TIMING ACKNOWLEDGE SEQUENCE WAVEFORM Acknowledge sequence starts here, write to SSPCON2, ACKEN = 1, ACKDT = 0 SDA D0 SCL 8 ACKEN automatically cleared TBRG TBRG ACK 9 SSPIF SSPIF set at the end of receive Cleared in software Cleared in software SSPIF set at the end of Acknowledge sequence Note: TBRG = one Baud Rate Generator period. FIGURE 17-26: STOP CONDITION RECEIVE OR TRANSMIT MODE Write to SSPCON2, set PEN Falling edge of 9th clock SCL SDA SCL = 1 for TBRG, followed by SDA = 1 for TBRG after SDA sampled high. P bit (SSPSTAT<4>) is set. PEN bit (SSPCON2<2>) is cleared by hardware and the SSPIF bit is set TBRG ACK P TBRG TBRG TBRG SCL brought high after TBRG SDA asserted low before rising edge of clock to setup Stop condition Note: TBRG = one Baud Rate Generator period. DS39770C-page 228 2010 Microchip Technology Inc. PIC18F85J90 FAMILY 17.4.14 SLEEP OPERATION 17.4.17 2 While in Sleep mode, the I C module can receive addresses or data and when an address match or complete byte transfer occurs, wake the processor from Sleep (if the MSSP interrupt is enabled). 17.4.15 EFFECTS OF A RESET A Reset disables the MSSP module and terminates the current transfer. 17.4.16 MULTI-MASTER MODE In Multi-Master mode, the interrupt generation on the detection of the Start and Stop conditions allows the determination of when the bus is free. The Stop (P) and Start (S) bits are cleared from a Reset or when the MSSP module is disabled. Control of the I 2C bus may be taken when the P bit (SSPSTAT<4>) is set, or the bus is Idle, with both the S and P bits clear. When the bus is busy, enabling the MSSP interrupt will generate the interrupt when the Stop condition occurs. In multi-master operation, the SDA line must be monitored for arbitration to see if the signal level is the expected output level. This check is performed in hardware with the result placed in the BCLIF bit. The states where arbitration can be lost are: * * * * * Address Transfer Data Transfer A Start Condition A Repeated Start Condition An Acknowledge Condition MULTI -MASTER COMMUNICATION, BUS COLLISION AND BUS ARBITRATION Multi-Master mode support is achieved by bus arbitration. When the master outputs address/data bits onto the SDA pin, arbitration takes place when the master outputs a `1' on SDA by letting SDA float high, and another master asserts a `0'. When the SCL pin floats high, data should be stable. If the expected data on SDA is a `1' and the data sampled on the SDA pin = 0, then a bus collision has taken place. The master will set the Bus Collision Interrupt Flag, BCLIF and reset the I2C port to its Idle state (Figure 17-27). If a transmit was in progress when the bus collision occurred, the transmission is halted, the BF flag is cleared, the SDA and SCL lines are deasserted and the SSPBUF can be written to. When the user services the bus collision Interrupt Service Routine and if the I2C bus is free, the user can resume communication by asserting a Start condition. If a Start, Repeated Start, Stop or Acknowledge condition was in progress when the bus collision occurred, the condition is aborted, the SDA and SCL lines are deasserted and the respective control bits in the SSPCON2 register are cleared. When the user services the bus collision Interrupt Service Routine and if the I2C bus is free, the user can resume communication by asserting a Start condition. The master will continue to monitor the SDA and SCL pins. If a Stop condition occurs, the SSPIF bit will be set. A write to the SSPBUF will start the transmission of data at the first data bit regardless of where the transmitter left off when the bus collision occurred. In Multi-Master mode, the interrupt generation on the detection of Start and Stop conditions allows the determination of when the bus is free. Control of the I2C bus can be taken when the P bit is set in the SSPSTAT register, or the bus is Idle and the S and P bits are cleared. FIGURE 17-27: BUS COLLISION TIMING FOR TRANSMIT AND ACKNOWLEDGE Data changes while SCL = 0 SDA line pulled low by another source SDA released by master Sample SDA. While SCL is high, data doesn't match what is driven by the master. Bus collision has occurred. SDA SCL Set Bus Collision Interrupt (BCLIF) BCLIF 2010 Microchip Technology Inc. DS39770C-page 229 PIC18F85J90 FAMILY 17.4.17.1 Bus Collision During a Start Condition During a Start condition, a bus collision occurs if: a) b) SDA or SCL are sampled low at the beginning of the Start condition (Figure 17-28). SCL is sampled low before SDA is asserted low (Figure 17-29). During a Start condition, both the SDA and the SCL pins are monitored. If the SDA pin is sampled low during this count, the BRG is reset and the SDA line is asserted early (Figure 17-30). If, however, a `1' is sampled on the SDA pin, the SDA pin is asserted low at the end of the BRG count. The Baud Rate Generator is then reloaded and counts down to 0. If the SCL pin is sampled as `0' during this time, a bus collision does not occur. At the end of the BRG count, the SCL pin is asserted low. Note: If the SDA pin is already low, or the SCL pin is already low, then all of the following occur: * the Start condition is aborted; * the BCLIF flag is set; and * the MSSP module is reset to its Idle state (Figure 17-28). The Start condition begins with the SDA and SCL pins deasserted. When the SDA pin is sampled high, the Baud Rate Generator is loaded from SSPADD<6:0> and counts down to 0. If the SCL pin is sampled low while SDA is high, a bus collision occurs, because it is assumed that another master is attempting to drive a data `1' during the Start condition. FIGURE 17-28: The reason that bus collision is not a factor during a Start condition is that no two bus masters can assert a Start condition at the exact same time. Therefore, one master will always assert SDA before the other. This condition does not cause a bus collision because the two masters must be allowed to arbitrate the first address following the Start condition. If the address is the same, arbitration must be allowed to continue into the data portion, Repeated Start or Stop conditions. BUS COLLISION DURING START CONDITION (SDA ONLY) SDA goes low before the SEN bit is set. Set BCLIF, S bit and SSPIF set because SDA = 0, SCL = 1. SDA SCL Set SEN, enable Start condition if SDA = 1, SCL = 1 SEN cleared automatically because of bus collision. MSSP module reset into Idle state. SEN BCLIF SDA sampled low before Start condition. Set BCLIF. S bit and SSPIF set because SDA = 0, SCL = 1. SSPIF and BCLIF are cleared in software S SSPIF SSPIF and BCLIF are cleared in software DS39770C-page 230 2010 Microchip Technology Inc. PIC18F85J90 FAMILY FIGURE 17-29: BUS COLLISION DURING START CONDITION (SCL = 0) SDA = 0, SCL = 1 TBRG TBRG SDA Set SEN, enable Start sequence if SDA = 1, SCL = 1 SCL SCL = 0 before SDA = 0, bus collision occurs. Set BCLIF. SEN SCL = 0 before BRG time-out, bus collision occurs. Set BCLIF. BCLIF Interrupt cleared in software S `0' `0' SSPIF `0' `0' FIGURE 17-30: BRG RESET DUE TO SDA ARBITRATION DURING START CONDITION SDA = 0, SCL = 1 Set S Less than TBRG SDA Set SSPIF TBRG SDA pulled low by other master. Reset BRG and assert SDA. SCL S SCL pulled low after BRG time-out SEN BCLIF Set SEN, enable Start sequence if SDA = 1, SCL = 1 `0' S SSPIF SDA = 0, SCL = 1, set SSPIF 2010 Microchip Technology Inc. Interrupts cleared in software DS39770C-page 231 PIC18F85J90 FAMILY 17.4.17.2 Bus Collision During a Repeated Start Condition If SDA is low, a bus collision has occurred (i.e., another master is attempting to transmit a data `0', see Figure 17-31). If SDA is sampled high, the BRG is reloaded and begins counting. If SDA goes from high-to-low before the BRG times out, no bus collision occurs because no two masters can assert SDA at exactly the same time. During a Repeated Start condition, a bus collision occurs if: a) b) A low level is sampled on SDA when SCL goes from low level to high level. SCL goes low before SDA is asserted low, indicating that another master is attempting to transmit a data `1'. If SCL goes from high-to-low before the BRG times out and SDA has not already been asserted, a bus collision occurs. In this case, another master is attempting to transmit a data `1' during the Repeated Start condition (see Figure 17-32). When the user deasserts SDA and the pin is allowed to float high, the BRG is loaded with SSPADD<6:0> and counts down to 0. The SCL pin is then deasserted and when sampled high, the SDA pin is sampled. FIGURE 17-31: If, at the end of the BRG time-out, both SCL and SDA are still high, the SDA pin is driven low and the BRG is reloaded and begins counting. At the end of the count, regardless of the status of the SCL pin, the SCL pin is driven low and the Repeated Start condition is complete. BUS COLLISION DURING A REPEATED START CONDITION (CASE 1) SDA SCL Sample SDA when SCL goes high. If SDA = 0, set BCLIF and release SDA and SCL. RSEN BCLIF Cleared in software S `0' SSPIF `0' FIGURE 17-32: BUS COLLISION DURING REPEATED START CONDITION (CASE 2) TBRG TBRG SDA SCL BCLIF SCL goes low before SDA, set BCLIF. Release SDA and SCL. Interrupt cleared in software RSEN S `0' SSPIF DS39770C-page 232 2010 Microchip Technology Inc. PIC18F85J90 FAMILY 17.4.17.3 Bus Collision During a Stop Condition The Stop condition begins with SDA asserted low. When SDA is sampled low, the SCL pin is allowed to float. When the pin is sampled high (clock arbitration), the Baud Rate Generator is loaded with SSPADD<6:0> and counts down to 0. After the BRG times out, SDA is sampled. If SDA is sampled low, a bus collision has occurred. This is due to another master attempting to drive a data `0' (Figure 17-33). If the SCL pin is sampled low before SDA is allowed to float high, a bus collision occurs. This is another case of another master attempting to drive a data `0' (Figure 17-34). Bus collision occurs during a Stop condition if: a) b) After the SDA pin has been deasserted and allowed to float high, SDA is sampled low after the BRG has timed out. After the SCL pin is deasserted, SCL is sampled low before SDA goes high. FIGURE 17-33: BUS COLLISION DURING A STOP CONDITION (CASE 1) TBRG TBRG TBRG SDA SDA sampled low after TBRG, set BCLIF SDA asserted low SCL PEN BCLIF P `0' SSPIF `0' FIGURE 17-34: BUS COLLISION DURING A STOP CONDITION (CASE 2) TBRG TBRG TBRG SDA Assert SDA SCL SCL goes low before SDA goes high, set BCLIF PEN BCLIF P `0' SSPIF `0' 2010 Microchip Technology Inc. DS39770C-page 233 PIC18F85J90 FAMILY TABLE 17-4: Name INTCON REGISTERS ASSOCIATED WITH I2CTM OPERATION Bit 7 Bit 6 GIE/GIEH PEIE/GIEL Bit 5 Bit 4 Bit 3 Bit 2 Bit 1 Bit 0 Reset Values on Page TMR0IE INT0IE RBIE TMR0IF INT0IF RBIF 57 PIR1 -- ADIF RC1IF TX1IF SSPIF -- TMR2IF TMR1IF 60 PIE1 -- ADIE RC1IE TX1IE SSPIE -- TMR2IE TMR1IE 60 IPR1 -- ADIP RC1IP TX1IP SSPIP -- TMR2IP TMR1IP 60 PIR2 OSCFIF CMIF -- -- BCLIF LVDIF TMR3IF -- 60 PIE2 OSCFIE CMIE -- -- BCLIE LVDIE TMR3IE -- 60 IPR2 OSCFIP CMIP -- -- BCLIP LVDIP TMR3IP -- 60 TRISC TRISC7 TRISC6 TRISC5 TRISC4 TRISC3 TRISC2 TRISC1 TRISC0 60 SSPBUF SSPADD MSSP Receive Buffer/Transmit Register 58 (I2CTM MSSP Address Register Slave mode), MSSP Baud Rate Reload Register (I2C Master mode) 58 SSPCON1 WCOL SSPOV SSPEN CKP SSPM3 SSPM2 SSPM1 SSPM0 58 SSPCON2 GCEN ACKSTAT ACKDT ACKEN RCEN PEN RSEN SEN 58 ACKSTAT ADMSK5(1) ADMSK4(1) ADMSK3(1) ADMSK2(1) ADMSK1(1) SEN D/A P S R/W UA BF GCEN SSPSTAT SMP CKE Legend: -- = unimplemented, read as `0'. Shaded cells are not used by the MSSP module in Note 1: Alternate bit definitions for use in I2C Slave mode operations only. DS39770C-page 234 I2CTM 58 mode. 2010 Microchip Technology Inc. PIC18F85J90 FAMILY 18.0 ENHANCED UNIVERSAL SYNCHRONOUS ASYNCHRONOUS RECEIVER TRANSMITTER (EUSART) PIC18F85J90 family devices have three serial I/O modules: the MSSP module, discussed in the previous chapter and two Universal Synchronous Asynchronous Receiver Transmitter (USART) modules. (Generically, the USART is also known as a Serial Communications Interface or SCI.) The USART can be configured as a full-duplex, asynchronous system that can communicate with peripheral devices, such as CRT terminals and personal computers. It can also be configured as a half-duplex synchronous system that can communicate with peripheral devices, such as A/D or D/A integrated circuits, serial EEPROMs, etc. There are two distinct implementations of the USART module in these devices: the Enhanced USART (EUSART) discussed here and the Addressable USART discussed in the next chapter. For this device family, USART1 always refers to the EUSART, while USART2 is always the AUSART. The EUSART and AUSART modules implement the same core features for serial communications; their basic operation is essentially the same. The EUSART module provides additional features, including Automatic Baud Rate Detection and calibration, automatic wake-up on Sync Break reception and 12-bit Break character transmit. These features make it ideally suited for use in Local Interconnect Network bus (LIN/J2602 bus) systems. The pins of the EUSART are multiplexed with the functions of PORTC (RC6/TX1/CK1/SEG27 and RC7/RX1/DT1/SEG28). In order to configure these pins as an EUSART: * bit, SPEN (RCSTA1<7>), must be set (= 1) * bit, TRISC<7>, must be set (= 1) * bit, TRISC<6>, must be set (= 1) Note: The EUSART control will automatically reconfigure the pin from input to output as needed. The driver for the TX1 output pin can also be optionally configured as an open-drain output. This feature allows the voltage level on the pin to be pulled to a higher level through an external pull-up resistor, and allows the output to communicate with external circuits without the need for additional level shifters. The open-drain output option is controlled by the U1OD bit (LATG<6>). Setting the bit configures the pin for open-drain operation. 18.1 Control Registers The operation of the Enhanced USART module is controlled through three registers: * Transmit Status and Control Register 1 (TXSTA1) * Receive Status and Control Register 1 (RCSTA1) * Baud Rate Control Register 1 (BAUDCON1) The registers are described Register 18-2 and Register 18-3. in Register 18-1, The EUSART can be configured in the following modes: * Asynchronous (full-duplex) with: - Auto-wake-up on character reception - Auto-baud calibration - 12-bit Break character transmission * Synchronous - Master (half-duplex) with selectable clock polarity * Synchronous - Slave (half-duplex) with selectable clock polarity 2010 Microchip Technology Inc. DS39770C-page 235 PIC18F85J90 FAMILY REGISTER 18-1: TXSTA1: EUSART TRANSMIT STATUS AND CONTROL REGISTER R/W-0 R/W-0 R/W-0 R/W-0 R/W-0 R/W-0 R-1 R/W-0 CSRC TX9 TXEN(1) SYNC SENDB BRGH TRMT TX9D bit 7 bit 0 Legend: R = Readable bit W = Writable bit U = Unimplemented bit, read as `0' -n = Value at POR `1' = Bit is set `0' = Bit is cleared x = Bit is unknown bit 7 CSRC: Clock Source Select bit Asynchronous mode: Don't care. Synchronous mode: 1 = Master mode (clock generated internally from BRG) 0 = Slave mode (clock from external source) bit 6 TX9: 9-Bit Transmit Enable bit 1 = Selects 9-bit transmission 0 = Selects 8-bit transmission bit 5 TXEN: Transmit Enable bit(1) 1 = Transmit enabled 0 = Transmit disabled bit 4 SYNC: AUSART Mode Select bit 1 = Synchronous mode 0 = Asynchronous mode bit 3 SENDB: Send Break Character bit Asynchronous mode: 1 = Send Sync Break on next transmission (cleared by hardware upon completion) 0 = Sync Break transmission completed Synchronous mode: Don't care. bit 2 BRGH: High Baud Rate Select bit Asynchronous mode: 1 = High speed 0 = Low speed Synchronous mode: Unused in this mode. bit 1 TRMT: Transmit Shift Register Status bit 1 = TSR empty 0 = TSR full bit 0 TX9D: 9th bit of Transmit Data Can be address/data bit or a parity bit. Note 1: SREN/CREN overrides TXEN in Sync mode. DS39770C-page 236 2010 Microchip Technology Inc. PIC18F85J90 FAMILY REGISTER 18-2: RCSTA1: EUSART RECEIVE STATUS AND CONTROL REGISTER R/W-0 R/W-0 R/W-0 R/W-0 R/W-0 R-0 R-0 R-x SPEN RX9 SREN CREN ADDEN FERR OERR RX9D bit 7 bit 0 Legend: R = Readable bit W = Writable bit U = Unimplemented bit, read as `0' -n = Value at POR `1' = Bit is set `0' = Bit is cleared x = Bit is unknown bit 7 SPEN: Serial Port Enable bit 1 = Serial port enabled 0 = Serial port disabled (held in Reset) bit 6 RX9: 9-Bit Receive Enable bit 1 = Selects 9-bit reception 0 = Selects 8-bit reception bit 5 SREN: Single Receive Enable bit Asynchronous mode: Don't care. Synchronous mode - Master: 1 = Enables single receive 0 = Disables single receive This bit is cleared after reception is complete. Synchronous mode - Slave: Don't care. bit 4 CREN: Continuous Receive Enable bit Asynchronous mode: 1 = Enables receiver 0 = Disables receiver Synchronous mode: 1 = Enables continuous receive until enable bit, CREN, is cleared (CREN overrides SREN) 0 = Disables continuous receive bit 3 ADDEN: Address Detect Enable bit Asynchronous mode 9-bit (RX9 = 1): 1 = Enables address detection, enables interrupt and loads the receive buffer when RSR<8> is set 0 = Disables address detection, all bytes are received and ninth bit can be used as parity bit Asynchronous mode 9-bit (RX9 = 0): Don't care. bit 2 FERR: Framing Error bit 1 = Framing error (can be cleared by reading RCREG1 register and receiving the next valid byte) 0 = No framing error bit 1 OERR: Overrun Error bit 1 = Overrun error (can be cleared by clearing bit, CREN) 0 = No overrun error bit 0 RX9D: 9th bit of Received Data This can be an address/data bit or a parity bit and must be calculated by user firmware. 2010 Microchip Technology Inc. DS39770C-page 237 PIC18F85J90 FAMILY REGISTER 18-3: BAUDCON1: BAUD RATE CONTROL REGISTER 1 R/W-0 R-1 R/W-0 R/W-0 R/W-0 U-0 R/W-0 R/W-0 ABDOVF RCIDL RXDTP TXCKP BRG16 -- WUE ABDEN bit 7 bit 0 Legend: R = Readable bit W = Writable bit U = Unimplemented bit, read as `0' -n = Value at POR `1' = Bit is set `0' = Bit is cleared x = Bit is unknown bit 7 ABDOVF: Auto-Baud Acquisition Rollover Status bit 1 = A BRG rollover has occurred during Auto-Baud Rate Detect mode (must be cleared in software) 0 = No BRG rollover has occurred bit 6 RCIDL: Receive Operation Idle Status bit 1 = Receive operation is Idle 0 = Receive operation is active bit 5 RXDTP: Received Data Polarity Select bit (Asynchronous mode only) Asynchronous mode: 1 = RX data is inverted 0 = RX data received is not inverted bit 4 TXCKP: Clock and Data Polarity Select bit Asynchronous mode: 1 = Idle state for transmit (TX) is a low level 0 = Idle state for transmit (TX) is a high level Synchronous mode: 1 = Idle state for clock (CK) is a high level 0 = Idle state for clock (CK) is a low level bit 3 BRG16: 16-Bit Baud Rate Register Enable bit 1 = 16-bit Baud Rate Generator - SPBRGH1 and SPBRG1 0 = 8-bit Baud Rate Generator - SPBRG1 only (Compatible mode), SPBRGH1 value ignored bit 2 Unimplemented: Read as `0' bit 1 WUE: Wake-up Enable bit Asynchronous mode: 1 = EUSART will continue to sample the RX1 pin - interrupt generated on falling edge; bit cleared in hardware on following rising edge 0 = RX1 pin not monitored or rising edge detected Synchronous mode: Unused in this mode. bit 0 ABDEN: Auto-Baud Detect Enable bit Asynchronous mode: 1 = Enable baud rate measurement on the next character. Requires reception of a Sync field (55h); cleared in hardware upon completion. 0 = Baud rate measurement disabled or completed Synchronous mode: Unused in this mode. DS39770C-page 238 2010 Microchip Technology Inc. PIC18F85J90 FAMILY 18.2 EUSART Baud Rate Generator (BRG) The BRG is a dedicated, 8-bit or 16-bit generator that supports both the Asynchronous and Synchronous modes of the EUSART. By default, the BRG operates in 8-bit mode; setting the BRG16 bit (BAUDCON1<3>) selects 16-bit mode. The SPBRGH1:SPBRG1 register pair controls the period of a free-running timer. In Asynchronous mode, BRGH (TXSTA1<2>) and BRG16 (BAUDCON1<3>) bits also control the baud rate. In Synchronous mode, BRGH is ignored. Table 18-1 shows the formula for computation of the baud rate for different EUSART modes that only apply in Master mode (internally generated clock). Given the desired baud rate and FOSC, the nearest integer value for the SPBRGH1:SPBRG1 registers can be calculated using the formulas in Table 18-1. From this, the error in baud rate can be determined. An example calculation is shown in Example 18-1. Typical baud rates and error values for the various Asynchronous modes are shown in Table 18-2. It may be advantageous to use TABLE 18-1: the high baud rate (BRGH = 1) or the 16-bit BRG to reduce the baud rate error, or achieve a slow baud rate for a fast oscillator frequency. Writing a new value to the SPBRGH1:SPBRG1 registers causes the BRG timer to be reset (or cleared). This ensures the BRG does not wait for a timer overflow before outputting the new baud rate. When operated in the Synchronous mode, SPBRGH:SPBRG values of 0000h and 0001h are not supported. In the Asynchronous mode, all BRG values may be used. 18.2.1 OPERATION IN POWER-MANAGED MODES The device clock is used to generate the desired baud rate. When one of the power-managed modes is entered, the new clock source may be operating at a different frequency. This may require an adjustment to the value in the SPBRG1 register pair. 18.2.2 SAMPLING The data on the RX1 pin is sampled three times by a majority detect circuit to determine if a high or a low level is present at the RX1 pin. BAUD RATE FORMULAS Configuration Bits SYNC BRG16 BRGH BRG/EUSART Mode 0 0 0 8-bit/Asynchronous 0 0 1 8-bit/Asynchronous 0 1 0 16-bit/Asynchronous 0 1 1 16-bit/Asynchronous 1 0 x 8-bit/Synchronous 1 1 x 16-bit/Synchronous Legend: x = Don't care, n = Value of SPBRGH1:SPBRG1 register pair 2010 Microchip Technology Inc. Baud Rate Formula FOSC/[64 (n + 1)] FOSC/[16 (n + 1)] FOSC/[4 (n + 1)] DS39770C-page 239 PIC18F85J90 FAMILY EXAMPLE 18-1: CALCULATING BAUD RATE ERROR For a device with FOSC of 16 MHz, desired baud rate of 9600, Asynchronous mode, 8-bit BRG: Desired Baud Rate = FOSC/(64 ([SPBRGH1:SPBRG1] + 1)) Solving for SPBRGH1:SPBRG1: X = ((FOSC/Desired Baud Rate)/64) - 1 = ((16000000/9600)/64) - 1 = [25.042] = 25 Calculated Baud Rate = 16000000/(64 (25 + 1)) = 9615 Error = (Calculated Baud Rate - Desired Baud Rate)/Desired Baud Rate = (9615 - 9600)/9600 = 0.16% TABLE 18-2: Name REGISTERS ASSOCIATED WITH THE BAUD RATE GENERATOR Bit 7 Bit 6 Bit 5 Bit 4 Bit 3 Bit 2 Bit 1 CSRC TX9 TXEN SYNC SENDB BRGH TRMT TXSTA1 RCSTA1 SPEN RX9 SREN CREN ADDEN FERR OERR BAUDCON1 ABDOVF RCIDL RXDTP TXCKP BRG16 -- WUE SPBRGH1 EUSART Baud Rate Generator Register High Byte SPBRG1 EUSART Baud Rate Generator Register Low Byte Legend: -- = unimplemented, read as `0'. Shaded cells are not used by the BRG. DS39770C-page 240 Bit 0 TX9D RX9D ABDEN Reset Values on Page 59 59 61 61 59 2010 Microchip Technology Inc. PIC18F85J90 FAMILY TABLE 18-3: BAUD RATES FOR ASYNCHRONOUS MODES SYNC = 0, BRGH = 0, BRG16 = 0 BAUD RATE (K) FOSC = 40.000 MHz FOSC = 20.000 MHz Actual Rate (K) FOSC = 10.000 MHz Actual Rate (K) FOSC = 8.000 MHz Actual Rate (K) Actual Rate (K) % Error 0.3 -- -- -- -- -- -- -- -- -- -- -- -- 1.2 -- -- -- 1.221 1.73 255 1.202 0.16 129 1.201 -0.16 103 2.4 2.441 1.73 255 2.404 0.16 129 2.404 0.16 64 2.403 -0.16 51 9.6 9.615 0.16 64 9.766 1.73 31 9.766 1.73 15 9.615 -0.16 12 -- SPBRG value (decimal) % Error SPBRG value (decimal) % Error SPBRG value (decimal) % Error SPBRG value (decimal) 19.2 19.531 1.73 31 19.531 1.73 15 19.531 1.73 7 -- -- 57.6 56.818 -1.36 10 62.500 8.51 4 52.083 -9.58 2 -- -- -- 115.2 125.000 8.51 4 104.167 -9.58 2 78.125 -32.18 1 -- -- -- SYNC = 0, BRGH = 0, BRG16 = 0 BAUD RATE (K) FOSC = 4.000 MHz FOSC = 2.000 MHz FOSC = 1.000 MHz (decimal) Actual Rate (K) 0.16 207 0.300 -0.16 103 0.300 -0.16 51 0.16 51 1.201 -0.16 25 1.201 -0.16 12 2.404 0.16 25 2.403 -0.16 12 -- -- -- 9.6 8.929 -6.99 6 -- -- -- -- -- -- 19.2 20.833 8.51 2 -- -- -- -- -- -- 57.6 62.500 8.51 0 -- -- -- -- -- -- 115.2 62.500 -45.75 0 -- -- -- -- -- -- Actual Rate (K) % Error 0.3 0.300 1.2 1.202 2.4 SPBRG value % Error (decimal) Actual Rate (K) % Error SPBRG value SPBRG value (decimal) SYNC = 0, BRGH = 1, BRG16 = 0 BAUD RATE (K) FOSC = 40.000 MHz FOSC = 20.000 MHz (decimal) Actual Rate (K) % Error -- -- -- -- -- -- -- -- -- Actual Rate (K) % Error 0.3 -- 1.2 -- 2.4 -- SPBRG value FOSC = 10.000 MHz (decimal) Actual Rate (K) % Error -- -- -- -- -- -- -- -- 2.441 SPBRG value FOSC = 8.000 MHz (decimal) Actual Rate (K) % Error -- -- -- -- -- -- -- -- -- 1.73 255 2.403 -0.16 207 SPBRG value SPBRG value (decimal) -- 9.6 9.766 1.73 255 9.615 0.16 129 9.615 0.16 64 9.615 -0.16 51 19.2 19.231 0.16 129 19.231 0.16 64 19.531 1.73 31 19.230 -0.16 25 57.6 58.140 0.94 42 56.818 -1.36 21 56.818 -1.36 10 55.555 3.55 8 115.2 113.636 -1.36 21 113.636 -1.36 10 125.000 8.51 4 -- -- -- SYNC = 0, BRGH = 1, BRG16 = 0 BAUD RATE (K) FOSC = 4.000 MHz FOSC = 2.000 MHz (decimal) Actual Rate (K) % Error -- 207 -- 1.201 -- -0.16 0.16 103 2.403 0.16 25 9.615 19.231 0.16 12 57.6 62.500 8.51 115.2 125.000 8.51 Actual Rate (K) % Error 0.3 1.2 -- 1.202 -- 0.16 2.4 2.404 9.6 9.615 19.2 2010 Microchip Technology Inc. FOSC = 1.000 MHz (decimal) Actual Rate (K) % Error -- 103 0.300 1.201 -0.16 -0.16 207 51 -0.16 51 2.403 -0.16 25 -0.16 12 -- -- -- -- -- -- -- -- -- 3 -- -- -- -- -- -- 1 -- -- -- -- -- -- SPBRG value SPBRG value SPBRG value (decimal) DS39770C-page 241 PIC18F85J90 FAMILY TABLE 18-3: BAUD RATES FOR ASYNCHRONOUS MODES (CONTINUED) SYNC = 0, BRGH = 0, BRG16 = 1 BAUD RATE (K) FOSC = 40.000 MHz Actual Rate (K) % Error FOSC = 20.000 MHz SPBRG value (decimal) Actual Rate (K) % Error FOSC = 10.000 MHz (decimal) Actual Rate (K) SPBRG value % Error FOSC = 8.000 MHz (decimal) Actual Rate (K) % Error SPBRG value SPBRG value (decimal) 0.3 0.300 0.00 8332 0.300 0.02 4165 0.300 0.02 2082 0.300 -0.04 1.2 1.200 0.02 2082 1.200 -0.03 1041 1.200 -0.03 520 1.201 -0.16 1665 415 2.4 2.402 0.06 1040 2.399 -0.03 520 2.404 0.16 259 2.403 -0.16 207 9.6 9.615 0.16 259 9.615 0.16 129 9.615 0.16 64 9.615 -0.16 51 25 19.2 19.231 0.16 129 19.231 0.16 64 19.531 1.73 31 19.230 -0.16 57.6 58.140 0.94 42 56.818 -1.36 21 56.818 -1.36 10 55.555 3.55 8 115.2 113.636 -1.36 21 113.636 -1.36 10 125.000 8.51 4 -- -- -- SYNC = 0, BRGH = 0, BRG16 = 1 BAUD RATE (K) FOSC = 4.000 MHz FOSC = 2.000 MHz (decimal) Actual Rate (K) % Error 0.04 832 0.300 0.16 207 1.201 2.404 0.16 103 9.6 9.615 0.16 19.2 19.231 57.6 62.500 115.2 125.000 FOSC = 1.000 MHz (decimal) Actual Rate (K) % Error -0.16 415 0.300 -0.16 -0.16 103 1.201 -0.16 51 2.403 -0.16 51 2.403 -0.16 25 25 9.615 -0.16 12 -- -- -- 0.16 12 -- -- -- -- -- -- 8.51 3 -- -- -- -- -- -- 8.51 1 -- -- -- -- -- -- Actual Rate (K) % Error 0.3 0.300 1.2 1.202 2.4 SPBRG value SPBRG value SPBRG value (decimal) 207 SYNC = 0, BRGH = 1, BRG16 = 1 or SYNC = 1, BRG16 = 1 BAUD RATE (K) FOSC = 40.000 MHz FOSC = 20.000 MHz (decimal) Actual Rate (K) % Error 0.00 33332 0.300 0.00 8332 1.200 0.02 4165 Actual Rate (K) % Error 0.3 0.300 1.2 1.200 2.4 2.400 SPBRG value FOSC = 10.000 MHz (decimal) Actual Rate (K) % Error 0.00 16665 0.300 0.02 4165 1.200 2.400 0.02 2082 2.402 SPBRG value FOSC = 8.000 MHz (decimal) Actual Rate (K) % Error 0.00 8332 0.300 -0.01 6665 0.02 2082 1.200 -0.04 1665 0.06 1040 2.400 -0.04 832 SPBRG value SPBRG value (decimal) 9.6 9.606 0.06 1040 9.596 -0.03 520 9.615 0.16 259 9.615 -0.16 207 19.2 19.193 -0.03 520 19.231 0.16 259 19.231 0.16 129 19.230 -0.16 103 57.6 57.803 0.35 172 57.471 -0.22 86 58.140 0.94 42 57.142 0.79 34 115.2 114.943 -0.22 86 116.279 0.94 42 113.636 -1.36 21 117.647 -2.12 16 SYNC = 0, BRGH = 1, BRG16 = 1 or SYNC = 1, BRG16 = 1 BAUD RATE (K) 0.3 1.2 FOSC = 4.000 MHz Actual Rate (K) % Error 0.300 1.200 0.01 0.04 FOSC = 2.000 MHz (decimal) Actual Rate (K) % Error 3332 832 0.300 1.201 -0.04 -0.16 SPBRG value FOSC = 1.000 MHz (decimal) Actual Rate (K) % Error 1665 415 0.300 1.201 -0.04 -0.16 832 207 SPBRG value SPBRG value (decimal) 2.4 2.404 0.16 415 2.403 -0.16 207 2.403 -0.16 103 9.6 9.615 0.16 103 9.615 -0.16 51 9.615 -0.16 25 19.2 19.231 0.16 51 19.230 -0.16 25 19.230 -0.16 12 57.6 58.824 2.12 16 55.555 3.55 8 -- -- -- 115.2 111.111 -3.55 8 -- -- -- -- -- -- DS39770C-page 242 2010 Microchip Technology Inc. PIC18F85J90 FAMILY 18.2.3 AUTO-BAUD RATE DETECT The Enhanced USART module supports the automatic detection and calibration of baud rate. This feature is active only in Asynchronous mode and while the WUE bit is clear. The automatic baud rate measurement sequence (Figure 18-1) begins whenever a Start bit is received and the ABDEN bit is set. The calculation is self-averaging. While the ABD sequence takes place, the EUSART state machine is held in Idle. The RC1IF interrupt is set once the fifth rising edge on RX1 is detected. The value in the RCREG1 needs to be read to clear the RC1IF interrupt. The contents of RCREG1 should be discarded. Note 1: If the WUE bit is set with the ABDEN bit, Auto-Baud Rate Detection will occur on the byte following the Break character. 2: It is up to the user to determine that the incoming character baud rate is within the range of the selected BRG clock source. Some combinations of oscillator frequency and EUSART baud rates are not possible due to bit error rates. Overall system timing and communication baud rates must be taken into consideration when using the Auto-Baud Rate Detection feature. In the Auto-Baud Rate Detect (ABD) mode, the clock to the BRG is reversed. Rather than the BRG clocking the incoming RX1 signal, the RX1 signal is timing the BRG. In ABD mode, the internal Baud Rate Generator is used as a counter to time the bit period of the incoming serial byte stream. Once the ABDEN bit is set, the state machine will clear the BRG and look for a Start bit. The Auto-Baud Rate Detect must receive a byte with the value, 55h (ASCII "U", which is also the LIN/J2602 bus Sync character), in order to calculate the proper bit rate. The measurement is taken over both a low and a high bit time in order to minimize any effects caused by asymmetry of the incoming signal. After a Start bit, the SPBRG1 begins counting up, using the preselected clock source on the first rising edge of RX1. After eight bits on the RX1 pin or the fifth rising edge, an accumulated value totalling the proper BRG period is left in the SPBRGH1:SPBRG1 register pair. Once the 5th edge is seen (this should correspond to the Stop bit), the ABDEN bit is automatically cleared. If a rollover of the BRG occurs (an overflow from FFFFh to 0000h), the event is trapped by the ABDOVF status bit (BAUDCON1<7>). It is set in hardware by BRG rollovers and can be set or cleared by the user in software. ABD mode remains active after rollover events and the ABDEN bit remains set (Figure 18-2). While calibrating the baud rate period, the BRG registers are clocked at 1/8th the preconfigured clock rate. Note that the BRG clock can be configured by the BRG16 and BRGH bits. The BRG16 bit must be set to use both SPBRG1 and SPBRGH1 as a 16-bit counter. This allows the user to verify that no carry occurred for 8-bit modes by checking for 00h in the SPBRGH1 register. Refer to Table 18-4 for counter clock rates to the BRG. 2010 Microchip Technology Inc. TABLE 18-4: BRG COUNTER CLOCK RATES BRG16 BRGH BRG Counter Clock 0 0 FOSC/512 0 1 FOSC/128 1 0 FOSC/128 1 1 FOSC/32 Note: 18.2.3.1 During the ABD sequence, SPBRG1 and SPBRGH1 are both used as a 16-bit counter, independent of the BRG16 setting. ABD and EUSART Transmission Since the BRG clock is reversed during ABD acquisition, the EUSART transmitter cannot be used during ABD. This means that whenever the ABDEN bit is set, TXREG1 cannot be written to. Users should also ensure that ABDEN does not become set during a transmit sequence. Failing to do this may result in unpredictable EUSART operation. DS39770C-page 243 PIC18F85J90 FAMILY FIGURE 18-1: BRG Value AUTOMATIC BAUD RATE CALCULATION XXXXh 0000h 001Ch Start RX1 pin Edge #1 bit 1 bit 0 Edge #2 bit 3 bit 2 Edge #3 bit 5 bit 4 Edge #4 bit 7 bit 6 Edge #5 Stop bit BRG Clock Auto-Cleared Set by User ABDEN bit RC1IF bit (Interrupt) Read RCREG1 SPBRG1 XXXXh 1Ch SPBRGH1 XXXXh 00h Note: The ABD sequence requires the EUSART module to be configured in Asynchronous mode and WUE = 0. FIGURE 18-2: BRG OVERFLOW SEQUENCE BRG Clock ABDEN bit RX1 pin Start bit 0 ABDOVF bit FFFFh BRG Value DS39770C-page 244 XXXXh 0000h 0000h 2010 Microchip Technology Inc. PIC18F85J90 FAMILY 18.3 EUSART Asynchronous Mode Once the TXREG1 register transfers the data to the TSR register (occurs in one TCY), the TXREG1 register is empty and the TX1IF flag bit (PIR1<4>) is set. This interrupt can be enabled or disabled by setting or clearing the interrupt enable bit, TX1IE (PIE1<4>). TX1IF will be set regardless of the state of TX1IE; it cannot be cleared in software. TX1IF is also not cleared immediately upon loading TXREG1, but becomes valid in the second instruction cycle following the load instruction. Polling TX1IF immediately following a load of TXREG1 will return invalid results. The Asynchronous mode of operation is selected by clearing the SYNC bit (TXSTA1<4>). In this mode, the EUSART uses standard Non-Return-to-Zero (NRZ) format (one Start bit, eight or nine data bits and one Stop bit). The most common data format is 8 bits. An on-chip dedicated 8-bit/16-bit Baud Rate Generator can be used to derive standard baud rate frequencies from the oscillator. The EUSART transmits and receives the LSb first. The EUSART's transmitter and receiver are functionally independent, but use the same data format and baud rate. The Baud Rate Generator produces a clock, either x16 or x64 of the bit shift rate, depending on the BRGH and BRG16 bits (TXSTA1<2> and BAUDCON1<3>). Parity is not supported by the hardware but can be implemented in software and stored as the 9th data bit. While TX1IF indicates the status of the TXREG1 register, another bit, TRMT (TXSTA1<1>), shows the status of the TSR register. TRMT is a read-only bit which is set when the TSR register is empty. No interrupt logic is tied to this bit so the user has to poll this bit in order to determine if the TSR register is empty. Note 1: The TSR register is not mapped in data memory so it is not available to the user. When operating in Asynchronous mode, the EUSART module consists of the following important elements: * * * * * * * 2: Flag bit, TX1IF, is set when enable bit, TXEN, is set. Baud Rate Generator Sampling Circuit Asynchronous Transmitter Asynchronous Receiver Auto-Wake-up on Sync Break Character 12-Bit Break Character Transmit Auto-Baud Rate Detection 18.3.1 To set up an Asynchronous Transmission: 1. 2. EUSART ASYNCHRONOUS TRANSMITTER 3. 4. The EUSART transmitter block diagram is shown in Figure 18-3. The heart of the transmitter is the Transmit (Serial) Shift register (TSR). The Shift register obtains its data from the Read/Write Transmit Buffer register, TXREG1. The TXREG1 register is loaded with data in software. The TSR register is not loaded until the Stop bit has been transmitted from the previous load. As soon as the Stop bit is transmitted, the TSR is loaded with new data from the TXREG1 register (if available). FIGURE 18-3: 5. 6. 7. 8. Initialize the SPBRGH1:SPBRG1 registers for the appropriate baud rate. Set or clear the BRGH and BRG16 bits, as required, to achieve the desired baud rate. Enable the asynchronous serial port by clearing bit, SYNC, and setting bit, SPEN. If interrupts are desired, set enable bit, TX1IE. If 9-bit transmission is desired, set transmit bit, TX9; can be used as address/data bit. Enable the transmission by setting bit, TXEN, which will also set bit, TX1IF. If 9-bit transmission is selected, the ninth bit should be loaded in bit, TX9D. Load data to the TXREG1 register (starts transmission). If using interrupts, ensure that the GIE and PEIE bits in the INTCON register (INTCON<7:6>) are set. EUSART TRANSMIT BLOCK DIAGRAM Data Bus TX1IF TXREG1 Register TX1IE 8 MSb (8) LSb Pin Buffer and Control 0 TSR Register TX1 pin Interrupt TXEN Baud Rate CLK TRMT BRG16 SPBRGH1 SPBRG1 Baud Rate Generator 2010 Microchip Technology Inc. SPEN TX9 TX9D DS39770C-page 245 PIC18F85J90 FAMILY FIGURE 18-4: ASYNCHRONOUS TRANSMISSION Write to TXREG1 Word 1 BRG Output (Shift Clock) TX1 (pin) Start bit bit 0 bit 1 bit 7/8 Stop bit Word 1 TX1IF bit (Transmit Buffer Reg. Empty Flag) 1 TCY Word 1 Transmit Shift Reg TRMT bit (Transmit Shift Reg. Empty Flag) FIGURE 18-5: ASYNCHRONOUS TRANSMISSION (BACK TO BACK) Write to TXREG1 Word 2 Word 1 BRG Output (Shift Clock) TX1 (pin) Start bit bit 1 1 TCY TX1IF bit (Interrupt Reg. Flag) bit 7/8 Stop bit Start bit bit 0 Word 2 Word 1 1 TCY Word 1 Transmit Shift Reg. TRMT bit (Transmit Shift Reg. Empty Flag) Note: bit 0 Word 2 Transmit Shift Reg. This timing diagram shows two consecutive transmissions. TABLE 18-5: Name INTCON REGISTERS ASSOCIATED WITH ASYNCHRONOUS TRANSMISSION Bit 7 Bit 6 GIE/GIEH PEIE/GIEL Bit 5 Bit 4 Bit 3 Bit 2 Bit 1 Bit 0 Reset Values on Page TMR0IE INT0IE RBIE TMR0IF INT0IF RBIF 57 PIR1 -- ADIF RC1IF TX1IF SSPIF -- TMR2IF TMR1IF 60 PIE1 -- ADIE RC1IE TX1IE SSPIE -- TMR2IE TMR1IE 60 -- ADIP RC1IP TX1IP SSPIP -- TMR2IP TMR1IP 60 SPEN RX9 SREN CREN ADDEN FERR OERR RX9D 59 IPR1 RCSTA1 TXREG1 EUSART Transmit Register 59 CSRC TX9 TXEN SYNC SENDB BRGH TRMT TX9D 59 BAUDCON1 ABDOVF RCIDL RXDTP TXCKP BRG16 -- WUE ABDEN 61 SPBRGH1 EUSART Baud Rate Generator Register High Byte SPBRG1 EUSART Baud Rate Generator Register Low Byte TXSTA1 LATG U2OD U1OD -- LATG4 LATG3 61 59 LATG2 LATG1 LATG0 60 Legend: -- = unimplemented locations read as `0'. Shaded cells are not used for asynchronous transmission. DS39770C-page 246 2010 Microchip Technology Inc. PIC18F85J90 FAMILY 18.3.2 EUSART ASYNCHRONOUS RECEIVER 18.3.3 The receiver block diagram is shown in Figure 18-6. The data is received on the RX1 pin and drives the data recovery block. The data recovery block is actually a high-speed shifter operating at x16 times the baud rate, whereas the main receive serial shifter operates at the bit rate or at FOSC. This mode would typically be used in RS-232 systems. This mode would typically be used in RS-485 systems. To set up an Asynchronous Reception with Address Detect Enable: 1. Initialize the SPBRGH1:SPBRG1 registers for the appropriate baud rate. Set or clear the BRGH and BRG16 bits, as required, to achieve the desired baud rate. 2. Enable the asynchronous serial port by clearing the SYNC bit and setting the SPEN bit. 3. If interrupts are required, set the RCEN bit and select the desired priority level with the RC1IP bit. 4. Set the RX9 bit to enable 9-bit reception. 5. Set the ADDEN bit to enable address detect. 6. Enable reception by setting the CREN bit. 7. The RC1IF bit will be set when reception is complete. The interrupt will be Acknowledged if the RC1IE and GIE bits are set. 8. Read the RCSTA1 register to determine if any error occurred during reception, as well as read bit 9 of data (if applicable). 9. Read RCREG1 to determine if the device is being addressed. 10. If any error occurred, clear the CREN bit. 11. If the device has been addressed, clear the ADDEN bit to allow all received data into the receive buffer and interrupt the CPU. To set up an Asynchronous Reception: 1. Initialize the SPBRGH1:SPBRG1 registers for the appropriate baud rate. Set or clear the BRGH and BRG16 bits, as required, to achieve the desired baud rate. 2. Enable the asynchronous serial port by clearing bit, SYNC, and setting bit, SPEN. 3. If interrupts are desired, set enable bit, RC1IE. 4. If 9-bit reception is desired, set bit, RX9. 5. Enable the reception by setting bit, CREN. 6. Flag bit, RC1IF, will be set when reception is complete and an interrupt will be generated if enable bit, RC1IE, was set. 7. Read the RCSTA1 register to get the 9th bit (if enabled) and determine if any error occurred during reception. 8. Read the 8-bit received data by reading the RCREG1 register. 9. If any error occurred, clear the error by clearing enable bit, CREN. 10. If using interrupts, ensure that the GIE and PEIE bits in the INTCON register (INTCON<7:6>) are set. FIGURE 18-6: SETTING UP 9-BIT MODE WITH ADDRESS DETECT EUSART RECEIVE BLOCK DIAGRAM CREN OERR FERR x64 Baud Rate CLK BRG16 SPBRGH1 SPBRG1 Baud Rate Generator 64 or 16 or 4 RSR Register MSb Stop (8) 7 LSb 1 0 Start RX9 Pin Buffer and Control Data Recovery RX1 RX9D RCREG1 Register FIFO SPEN 8 Interrupt RC1IF Data Bus RC1IE 2010 Microchip Technology Inc. DS39770C-page 247 PIC18F85J90 FAMILY FIGURE 18-7: ASYNCHRONOUS RECEPTION Start bit RX1 (pin) bit 0 bit 1 bit 7/8 Stop bit Rcv Shift Reg Rcv Buffer Reg Start bit bit 0 Stop bit Start bit bit 7/8 Stop bit Word 2 RCREG1 Word 1 RCREG1 RCREG1 Read Rcv Buffer Reg bit 7/8 RC1IF (Interrupt Flag) OERR bit CREN bit Note: This timing diagram shows three words appearing on the RX1 input. The RCREG1 (Receive Buffer register) is read after the third word causing the OERR (Overrun) bit to be set. TABLE 18-6: Name INTCON REGISTERS ASSOCIATED WITH ASYNCHRONOUS RECEPTION Bit 7 Bit 6 Bit 5 GIE/GIEH PEIE/GIEL TMR0IE Bit 4 Bit 3 Bit 2 Bit 1 Bit 0 Reset Values on Page INT0IE RBIE TMR0IF INT0IF RBIF 57 PIR1 -- ADIF RC1IF TX1IF SSPIF -- TMR2IF TMR1IF 60 PIE1 -- ADIE RC1IE TX1IE SSPIE -- TMR2IE TMR1IE 60 -- ADIP RC1IP TX1IP SSPIP -- TMR2IP TMR1IP 60 SPEN RX9 SREN CREN ADDEN FERR OERR RX9D 59 IPR1 RCSTA1 RCREG1 TXSTA1 EUSART Receive Register 59 CSRC TX9 TXEN SYNC SENDB BRGH TRMT TX9D 59 RCIDL RXDTP TXCKP BRG16 -- WUE ABDEN 61 BAUDCON1 ABDOVF SPBRGH1 EUSART Baud Rate Generator Register High Byte 61 SPBRG1 EUSART Baud Rate Generator Register Low Byte 59 Legend: -- = unimplemented locations read as `0'. Shaded cells are not used for asynchronous reception. DS39770C-page 248 2010 Microchip Technology Inc. PIC18F85J90 FAMILY 18.3.4 AUTO-WAKE-UP ON SYNC BREAK CHARACTER During Sleep mode, all clocks to the EUSART are suspended. Because of this, the Baud Rate Generator is inactive and a proper byte reception cannot be performed. The auto-wake-up feature allows the controller to wake-up, due to activity on the RX1/DT1 line, while the EUSART is operating in Asynchronous mode. The auto-wake-up feature is enabled by setting the WUE bit (BAUDCON<1>). Once set, the typical receive sequence on RX1/DT1 is disabled and the EUSART remains in an Idle state, monitoring for a wake-up event independent of the CPU mode. A wake-up event consists of a high-to-low transition on the RX1/DT1 line. (This coincides with the start of a Sync Break or a Wake-up Signal character for the LIN/J2602 protocol.) Following a wake-up event, the module generates an RC1IF interrupt. The interrupt is generated synchronously to the Q clocks in normal operating modes (Figure 18-8) and asynchronously, if the device is in Sleep mode (Figure 18-9). The interrupt condition is cleared by reading the RCREG1 register. The WUE bit is automatically cleared once a low-to-high transition is observed on the RX1 line following the wake-up event. At this point, the EUSART module is in Idle mode and returns to normal operation. This signals to the user that the Sync Break event is over. 18.3.4.1 Special Considerations Using Auto-Wake-up Since auto-wake-up functions by sensing rising edge transitions on RX1/DT1, information with any state changes before the Stop bit may signal a false FIGURE 18-8: End-Of-Character (EOC) and cause data or framing errors. Therefore, to work properly, the initial character in the transmission must be all `0's. This can be 00h (8 bits) for standard RS-232 devices, or 000h (12 bits) for LIN/J2602 bus. Oscillator start-up time must also be considered, especially in applications using oscillators with longer start-up intervals (i.e., XT or HS mode). The Sync Break (or Wake-up Signal) character must be of sufficient length and be followed by a sufficient interval to allow enough time for the selected oscillator to start and provide proper initialization of the EUSART. 18.3.4.2 Special Considerations Using the WUE Bit The timing of WUE and RC1IF events may cause some confusion when it comes to determining the validity of received data. As noted, setting the WUE bit places the EUSART in an Idle mode. The wake-up event causes a receive interrupt by setting the RC1IF bit. The WUE bit is cleared after this when a rising edge is seen on RX1/DT1. The interrupt condition is then cleared by reading the RCREG1 register. Ordinarily, the data in RCREG1 will be dummy data and should be discarded. The fact that the WUE bit has been cleared (or is still set) and the RC1IF flag is set should not be used as an indicator of the integrity of the data in RCREG1. Users should consider implementing a parallel method in firmware to verify received data integrity. To assure that no actual data is lost, check the RCIDL bit to verify that a receive operation is not in process. If a receive operation is not occurring, the WUE bit may then be set just prior to entering the Sleep mode. AUTO-WAKE-UP BIT (WUE) TIMINGS DURING NORMAL OPERATION Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 OSC1 Bit set by user WUE bit(1) Auto-Cleared RX1/DT1 Line RC1IF Note 1: Cleared due to user read of RCREG1 The EUSART remains in Idle while the WUE bit is set. FIGURE 18-9: AUTO-WAKE-UP BIT (WUE) TIMINGS DURING SLEEP Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 OSC1 WUE bit(2) Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Bit set by user Auto-Cleared RX1/DT1 Line Note 1 RC1IF SLEEP Command Executed Note 1: 2: Sleep Ends Cleared due to user read of RCREG1 If the wake-up event requires long oscillator warm-up time, the auto-clear of the WUE bit can occur while the stposc signal is still active. This sequence should not depend on the presence of Q clocks. The EUSART remains in Idle while the WUE bit is set. 2010 Microchip Technology Inc. DS39770C-page 249 PIC18F85J90 FAMILY 18.3.5 BREAK CHARACTER SEQUENCE The Enhanced USART module has the capability of sending the special Break character sequences that are required by the LIN/J2602 bus standard. The Break character transmit consists of a Start bit, followed by twelve `0' bits and a Stop bit. The Frame Break character is sent whenever the SENDB and TXEN bits (TXSTA<3> and TXSTA<5>) are set while the Transmit Shift register is loaded with data. Note that the value of data written to TXREG1 will be ignored and all `0's will be transmitted. The SENDB bit is automatically reset by hardware after the corresponding Stop bit is sent. This allows the user to preload the transmit FIFO with the next transmit byte following the Break character (typically, the Sync character in the LIN/J2602 specification). Note that the data value written to the TXREG1 for the Break character is ignored. The write simply serves the purpose of initiating the proper sequence. The TRMT bit indicates when the transmit operation is active or Idle, just as it does during normal transmission. See Figure 18-10 for the timing of the Break character sequence. 18.3.5.1 Break and Sync Transmit Sequence The following sequence will send a message frame header made up of a Break, followed by an Auto-Baud Sync byte. This sequence is typical of a LIN/J2602 bus master. FIGURE 18-10: Write to TXREG1 1. 2. 3. 4. 5. Configure the EUSART for the desired mode. Set the TXEN and SENDB bits to set up the Break character. Load the TXREG1 with a dummy character to initiate transmission (the value is ignored). Write `55h' to TXREG1 to load the Sync character into the transmit FIFO buffer. After the Break has been sent, the SENDB bit is reset by hardware. The Sync character now transmits in the preconfigured mode. When the TXREG1 becomes empty, as indicated by the TX1IF, the next data byte can be written to TXREG1. 18.3.6 RECEIVING A BREAK CHARACTER The Enhanced USART module can receive a Break character in two ways. The first method forces configuration of the baud rate at a frequency of 9/13 the typical speed. This allows for the Stop bit transition to be at the correct sampling location (13 bits for Break versus Start bit and 8 data bits for typical data). The second method uses the auto-wake-up feature described in Section 18.3.4 "Auto-Wake-up On Sync Break Character". By enabling this feature, the EUSART will sample the next two transitions on RX1/DT1, cause an RC1IF interrupt and receive the next data byte followed by another interrupt. Note that following a Break character, the user will typically want to enable the Auto-Baud Rate Detect feature. For both methods, the user can set the ABD bit once the TX1IF interrupt is observed. SEND BREAK CHARACTER SEQUENCE Dummy Write BRG Output (Shift Clock) TX1 (pin) Start bit bit 0 bit 1 bit 11 Stop bit Break TX1IF bit (Transmit Buffer Reg. Empty Flag) TRMT bit (Transmit Shift Reg. Empty Flag) SENDB sampled here Auto-Cleared SENDB (Transmit Shift Reg. Empty Flag) DS39770C-page 250 2010 Microchip Technology Inc. PIC18F85J90 FAMILY 18.4 EUSART Synchronous Master Mode Once the TXREG1 register transfers the data to the TSR register (occurs in one TCYCLE), the TXREG1 is empty and the TX1IF flag bit (PIR1<4>) is set. The interrupt can be enabled or disabled by setting or clearing the interrupt enable bit, TX1IE (PIE1<4>). TX1IF is set regardless of the state of enable bit TX1IE; it cannot be cleared in software. It will reset only when new data is loaded into the TXREG1 register. The Synchronous Master mode is entered by setting the CSRC bit (TXSTA<7>). In this mode, the data is transmitted in a half-duplex manner (i.e., transmission and reception do not occur at the same time). When transmitting data, the reception is inhibited and vice versa. Synchronous mode is entered by setting bit, SYNC (TXSTA<4>). In addition, enable bit, SPEN (RCSTA1<7>), is set in order to configure the TX1 and RX1 pins to CK1 (clock) and DT1 (data) lines, respectively. While flag bit, TX1IF, indicates the status of the TXREG1 register, another bit, TRMT (TXSTA<1>), shows the status of the TSR register. TRMT is a read-only bit which is set when the TSR is empty. No interrupt logic is tied to this bit so the user has to poll this bit in order to determine if the TSR register is empty. The TSR is not mapped in data memory so it is not available to the user. The Master mode indicates that the processor transmits the master clock on the CK1 line. Clock polarity is selected with the TXCKP bit (BAUDCON<4>). Setting TXCKP sets the Idle state on CK1 as high, while clearing the bit sets the Idle state as low. This option is provided to support Microwire devices with this module. 18.4.1 To set up a Synchronous Master Transmission: 1. EUSART SYNCHRONOUS MASTER TRANSMISSION 2. The EUSART transmitter block diagram is shown in Figure 18-3. The heart of the transmitter is the Transmit (Serial) Shift register (TSR). The Shift register obtains its data from the Read/Write Transmit Buffer register, TXREG1. The TXREG1 register is loaded with data in software. The TSR register is not loaded until the last bit has been transmitted from the previous load. As soon as the last bit is transmitted, the TSR is loaded with new data from the TXREG1 (if available). FIGURE 18-11: 7. 8. SYNCHRONOUS TRANSMISSION Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 RC7/RX1/DT1 pin bit 0 bit 1 bit 2 Q3 Q4 Q1 Q2 Q3 Q4 Q1Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1Q2 Q3 Q4 Q1 Q2 Q3 Q4 bit 7 Word 1 RC6/TX1/CK1 pin (TXCKP = 0) RC6/TX1/CK1 pin (TXCKP = 1) Write to TXREG1 Reg 3. 4. 5. 6. Initialize the SPBRGH1:SPBRG1 registers for the appropriate baud rate. Set or clear the BRG16 bit, as required, to achieve the desired baud rate. Enable the synchronous master serial port by setting bits, SYNC, SPEN and CSRC. If interrupts are desired, set enable bit, TX1IE. If 9-bit transmission is desired, set bit, TX9. Enable the transmission by setting bit, TXEN. If 9-bit transmission is selected, the ninth bit should be loaded in bit, TX9D. Start transmission by loading data to the TXREG1 register. If using interrupts, ensure that the GIE and PEIE bits in the INTCON register (INTCON<7:6>) are set. Write Word 1 bit 0 bit 1 bit 7 Word 2 Write Word 2 TX1IF bit (Interrupt Flag) TRMT bit TXEN bit Note: `1' `1' Sync Master mode, SPBRG1 = 0; continuous transmission of two 8-bit words. 2010 Microchip Technology Inc. DS39770C-page 251 PIC18F85J90 FAMILY FIGURE 18-12: SYNCHRONOUS TRANSMISSION (THROUGH TXEN) RC7/RX1/DT1 pin bit 0 bit 2 bit 1 bit 6 bit 7 RC6/TX1/CK1 pin Write to TXREG1 Reg TX1IF bit TRMT bit TXEN bit TABLE 18-7: Name INTCON REGISTERS ASSOCIATED WITH SYNCHRONOUS MASTER TRANSMISSION Bit 7 Bit 6 Bit 5 GIE/GIEH PEIE/GIEL TMR0IE Bit 4 Bit 3 Bit 2 Bit 1 Bit 0 Reset Values on Page INT0IE RBIE TMR0IF INT0IF RBIF 57 PIR1 -- ADIF RC1IF TX1IF SSPIF -- TMR2IF TMR1IF 60 PIE1 -- ADIE RC1IE TX1IE SSPIE -- TMR2IE TMR1IE 60 IPR1 -- ADIP RC1IP TX1IP SSPIP -- TMR2IP TMR1IP 60 SPEN RX9 SREN CREN ADDEN FERR OERR RX9D 59 RCSTA1 TXREG1 TXSTA1 EUSART Transmit Register CSRC BAUDCON1 ABDOVF 59 TX9 TXEN SYNC SENDB BRGH TRMT TX9D 59 RCIDL RXDTP TXCKP BRG16 -- WUE ABDEN 61 SPBRGH1 EUSART Baud Rate Generator Register High Byte 61 SPBRG1 EUSART Baud Rate Generator Register Low Byte 59 LATG U2OD U1OD -- LATG4 LATG3 LATG2 LATG1 LATG0 60 Legend: -- = unimplemented, read as `0'. Shaded cells are not used for synchronous master transmission. DS39770C-page 252 2010 Microchip Technology Inc. PIC18F85J90 FAMILY 18.4.2 EUSART SYNCHRONOUS MASTER RECEPTION Once Synchronous mode is selected, reception is enabled by setting either the Single Receive Enable bit, SREN (RCSTA1<5>), or the Continuous Receive Enable bit, CREN (RCSTA1<4>). Data is sampled on the RX1 pin on the falling edge of the clock. If enable bit, SREN, is set, only a single word is received. If enable bit, CREN, is set, the reception is continuous until CREN is cleared. If both bits are set, then CREN takes precedence. To set up a Synchronous Master Reception: 1. 2. Initialize the SPBRGH1:SPBRG1 registers for the appropriate baud rate. Set or clear the BRG16 bit, as required, to achieve the desired baud rate. Enable the synchronous master serial port by setting bits, SYNC, SPEN and CSRC. FIGURE 18-13: 3. 4. 5. 6. Ensure bits, CREN and SREN, are clear. If interrupts are desired, set enable bit, RC1IE. If 9-bit reception is desired, set bit, RX9. If a single reception is required, set bit, SREN. For continuous reception, set bit, CREN. 7. Interrupt flag bit, RC1IF, will be set when reception is complete and an interrupt will be generated if the enable bit, RC1IE, was set. 8. Read the RCSTA1 register to get the 9th bit (if enabled) and determine if any error occurred during reception. 9. Read the 8-bit received data by reading the RCREG1 register. 10. If any error occurred, clear the error by clearing bit, CREN. 11. If using interrupts, ensure that the GIE and PEIE bits in the INTCON register (INTCON<7:6>) are set. SYNCHRONOUS RECEPTION (MASTER MODE, SREN) Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 RC7/RX1/DT1 pin bit 0 bit 1 bit 2 bit 3 bit 4 bit 5 bit 6 bit 7 RC6/TX1/CK1 pin (TXCKP = 0) RC6/TX1/CK1 pin (TXCKP = 1) Write to SREN bit SREN bit CREN bit `0' `0' RC1IF bit (Interrupt) Read RCREG1 Note: Timing diagram demonstrates Sync Master mode with bit SREN = 1 and bit BRGH = 0. TABLE 18-8: Name INTCON REGISTERS ASSOCIATED WITH SYNCHRONOUS MASTER RECEPTION Bit 7 Bit 6 GIE/GIEH PEIE/GIEL Bit 5 Bit 4 Bit 3 Bit 2 Bit 1 Bit 0 Reset Values on Page TMR0IE INT0IE RBIE TMR0IF INT0IF RBIF 57 PIR1 -- ADIF RC1IF TX1IF SSPIF -- TMR2IF TMR1IF 60 PIE1 -- ADIE RC1IE TX1IE SSPIE -- TMR2IE TMR1IE 60 -- ADIP RC1IP TX1IP SSPIP -- TMR2IP TMR1IP 60 SPEN RX9 SREN CREN ADDEN FERR OERR RX9D 59 IPR1 RCSTA1 RCREG1 TXSTA1 EUSART Receive Register CSRC BAUDCON1 ABDOVF 59 TX9 TXEN SYNC SENDB BRGH TRMT TX9D RCIDL RXDTP TXCKP BRG16 -- WUE ABDEN 59 61 SPBRGH1 EUSART Baud Rate Generator Register High Byte 61 SPBRG1 EUSART Baud Rate Generator Register Low Byte 59 Legend: -- = unimplemented, read as `0'. Shaded cells are not used for synchronous master reception. 2010 Microchip Technology Inc. DS39770C-page 253 PIC18F85J90 FAMILY 18.5 EUSART Synchronous Slave Mode Synchronous Slave mode is entered by clearing bit CSRC (TXSTA<7>). This mode differs from the Synchronous Master mode in that the shift clock is supplied externally at the CK1 pin (instead of being supplied internally in Master mode). This allows the device to transfer or receive data while in any low-power mode. 18.5.1 EUSART SYNCHRONOUS SLAVE TRANSMIT If two words are written to the TXREG1 and then the SLEEP instruction is executed, the following will occur: b) c) d) e) 1. 2. 3. 4. 5. 6. The operation of the Synchronous Master and Slave modes are identical except in the case of the Sleep mode. a) To set up a Synchronous Slave Transmission: 7. 8. Enable the synchronous slave serial port by setting bits, SYNC and SPEN, and clearing bit, CSRC. Clear bits, CREN and SREN. If interrupts are desired, set enable bit, TX1IE. If 9-bit transmission is desired, set bit, TX9. Enable the transmission by setting enable bit, TXEN. If 9-bit transmission is selected, the ninth bit should be loaded in bit, TX9D. Start transmission by loading data to the TXREG1 register. If using interrupts, ensure that the GIE and PEIE bits in the INTCON register (INTCON<7:6>) are set. The first word will immediately transfer to the TSR register and transmit. The second word will remain in the TXREG1 register. Flag bit, TX1IF, will not be set. When the first word has been shifted out of TSR, the TXREG1 register will transfer the second word to the TSR and flag bit, TX1IF, will now be set. If enable bit, TX1IE, is set, the interrupt will wake the chip from Sleep. If the global interrupt is enabled, the program will branch to the interrupt vector. TABLE 18-9: Name REGISTERS ASSOCIATED WITH SYNCHRONOUS SLAVE TRANSMISSION Bit 7 Bit 6 Bit 5 Bit 4 Bit 3 Bit 2 Bit 1 Bit 0 Reset Values on Page TMR0IE INT0IE RBIE TMR0IF INT0IF RBIF 57 PIR1 -- ADIF RC1IF TX1IF SSPIF -- TMR2IF TMR1IF 60 PIE1 -- ADIE RC1IE TX1IE SSPIE -- TMR2IE TMR1IE 60 IPR1 -- ADIP RC1IP TX1IP SSPIP -- TMR2IP TMR1IP 60 SPEN RX9 SREN CREN ADDEN FERR OERR RX9D 59 INTCON RCSTA1 TXREG1 TXSTA1 GIE/GIEH PEIE/GIEL EUSART Transmit Register CSRC BAUDCON1 ABDOVF 59 TX9 TXEN SYNC SENDB BRGH TRMT TX9D 59 RCIDL RXDTP TXCKP BRG16 -- WUE ABDEN 61 SPBRGH1 EUSART Baud Rate Generator Register High Byte 61 SPBRG1 EUSART Baud Rate Generator Register Low Byte 59 LATG U2OD U1OD -- LATG4 LATG3 LATG2 LATG1 LATG0 60 Legend: -- = unimplemented, read as `0'. Shaded cells are not used for synchronous slave transmission. DS39770C-page 254 2010 Microchip Technology Inc. PIC18F85J90 FAMILY 18.5.2 EUSART SYNCHRONOUS SLAVE RECEPTION To set up a Synchronous Slave Reception: 1. The operation of the Synchronous Master and Slave modes is identical except in the case of Sleep or any Idle mode, and bit SREN, which is a "don't care" in Slave mode. If receive is enabled by setting the CREN bit prior to entering Sleep or any Idle mode, then a word may be received while in this low-power mode. Once the word is received, the RSR register will transfer the data to the RCREG1 register; if the RC1IE enable bit is set, the interrupt generated will wake the chip from the low-power mode. If the global interrupt is enabled, the program will branch to the interrupt vector. 2. 3. 4. 5. 6. 7. 8. 9. Enable the synchronous master serial port by setting bits, SYNC and SPEN, and clearing bit, CSRC. If interrupts are desired, set enable bit, RC1IE. If 9-bit reception is desired, set bit, RX9. To enable reception, set enable bit, CREN. Flag bit, RC1IF, will be set when reception is complete. An interrupt will be generated if enable bit, RC1IE, was set. Read the RCSTA1 register to get the 9th bit (if enabled) and determine if any error occurred during reception. Read the 8-bit received data by reading the RCREG1 register. If any error occurred, clear the error by clearing bit, CREN. If using interrupts, ensure that the GIE and PEIE bits in the INTCON register (INTCON<7:6>) are set. TABLE 18-10: REGISTERS ASSOCIATED WITH SYNCHRONOUS SLAVE RECEPTION Name INTCON Bit 7 Bit 6 Bit 5 GIE/GIEH PEIE/GIEL TMR0IE Bit 4 Bit 3 Bit 2 Bit 1 Bit 0 Reset Values on Page INT0IE RBIE TMR0IF INT0IF RBIF 57 PIR1 -- ADIF RC1IF TX1IF SSPIF -- TMR2IF TMR1IF 60 PIE1 -- ADIE RC1IE TX1IE SSPIE -- TMR2IE TMR1IE 60 IPR1 -- ADIP RC1IP TX1IP SSPIP -- TMR2IP TMR1IP 60 SPEN RX9 SREN CREN ADDEN FERR OERR RX9D RCSTA1 RCREG1 TXSTA1 EUSART Receive Register CSRC BAUDCON1 ABDOVF 59 59 TX9 TXEN SYNC SENDB BRGH TRMT TX9D 59 RCIDL RXDTP TXCKP BRG16 -- WUE ABDEN 61 SPBRGH1 EUSART Baud Rate Generator Register High Byte 61 SPBRG1 EUSART Baud Rate Generator Register Low Byte 59 Legend: -- = unimplemented, read as `0'. Shaded cells are not used for synchronous slave reception. 2010 Microchip Technology Inc. DS39770C-page 255 PIC18F85J90 FAMILY NOTES: DS39770C-page 256 2010 Microchip Technology Inc. PIC18F85J90 FAMILY 19.0 ADDRESSABLE UNIVERSAL SYNCHRONOUS ASYNCHRONOUS RECEIVER TRANSMITTER (AUSART) The Addressable Universal Synchronous Asynchronous Receiver Transmitter (AUSART) module is very similar in function to the Enhanced USART module, discussed in the previous chapter. It is provided as an additional channel for serial communication with external devices, for those situations that do not require auto-baud detection or LIN/J2602 bus support. The AUSART can be configured in the following modes: * Asynchronous (full duplex) * Synchronous - Master (half duplex) * Synchronous - Slave (half duplex) The pins of the AUSART module are multiplexed with the functions of PORTG (RG1/TX2/CK2 and RG2/RX2/DT2/VLCAP1, respectively). In order to configure these pins as an AUSART: Note: The AUSART control will automatically reconfigure the pin from input to output as needed. The driver for the TX2 output pin can also be optionally configured as an open-drain output. This feature allows the voltage level on the pin to be pulled to a higher level through an external pull-up resistor, and allows the output to communicate with external circuits without the need for additional level shifters. The open-drain output option is controlled by the U2OD bit (LATG<7>). Setting the bit configures the pin for open-drain operation. 19.1 Control Registers The operation of the Addressable USART module is controlled through two registers, TXSTA2 and RXSTA2. These are detailed in Register 19-1 and Register 19-2, respectively. * bit, SPEN (RCSTA2<7>), must be set (= 1) * bit, TRISG<2>, must be set (= 1) * bit, TRISG<1>, must be cleared (= 0) for Asynchronous and Synchronous Master modes * bit, TRISG<1>, must be set (= 1) for Synchronous Slave mode 2010 Microchip Technology Inc. DS39770C-page 257 PIC18F85J90 FAMILY REGISTER 19-1: TXSTA2: AUSART TRANSMIT STATUS AND CONTROL REGISTER R/W-0 R/W-0 R/W-0 R/W-0 U-0 R/W-0 R-1 R/W-0 CSRC TX9 TXEN(1) SYNC -- BRGH TRMT TX9D bit 7 bit 0 Legend: R = Readable bit W = Writable bit U = Unimplemented bit, read as `0' -n = Value at POR `1' = Bit is set `0' = Bit is cleared bit 7 CSRC: Clock Source Select bit Asynchronous mode: Don't care. Synchronous mode: 1 = Master mode (clock generated internally from BRG) 0 = Slave mode (clock from external source) bit 6 TX9: 9-Bit Transmit Enable bit 1 = Selects 9-bit transmission 0 = Selects 8-bit transmission bit 5 TXEN: Transmit Enable bit(1) 1 = Transmit enabled 0 = Transmit disabled bit 4 SYNC: AUSART Mode Select bit 1 = Synchronous mode 0 = Asynchronous mode bit 3 Unimplemented: Read as `0' bit 2 BRGH: High Baud Rate Select bit Asynchronous mode: 1 = High speed 0 = Low speed Synchronous mode: Unused in this mode. bit 1 TRMT: Transmit Shift Register Status bit 1 = TSR empty 0 = TSR full bit 0 TX9D: 9th bit of Transmit Data Can be address/data bit or a parity bit. Note 1: x = Bit is unknown SREN/CREN overrides TXEN in Sync mode. DS39770C-page 258 2010 Microchip Technology Inc. PIC18F85J90 FAMILY REGISTER 19-2: RCSTA2: AUSART RECEIVE STATUS AND CONTROL REGISTER R/W-0 R/W-0 R/W-0 R/W-0 R/W-0 R-0 R-0 R-x SPEN RX9 SREN CREN ADDEN FERR OERR RX9D bit 7 bit 0 Legend: R = Readable bit W = Writable bit U = Unimplemented bit, read as `0' -n = Value at POR `1' = Bit is set `0' = Bit is cleared x = Bit is unknown bit 7 SPEN: Serial Port Enable bit 1 = Serial port enabled (configures RX2/DT2 and TX2/CK2 (TXEN = 1) pins as serial port pins) 0 = Serial port disabled (held in Reset) bit 6 RX9: 9-Bit Receive Enable bit 1 = Selects 9-bit reception 0 = Selects 8-bit reception bit 5 SREN: Single Receive Enable bit Asynchronous mode: Don't care. Synchronous mode - Master: 1 = Enables single receive 0 = Disables single receive This bit is cleared after reception is complete. Synchronous mode - Slave: Don't care. bit 4 CREN: Continuous Receive Enable bit Asynchronous mode: 1 = Enables receiver 0 = Disables receiver Synchronous mode: 1 = Enables continuous receive until enable bit, CREN, is cleared (CREN overrides SREN) 0 = Disables continuous receive bit 3 ADDEN: Address Detect Enable bit Asynchronous mode 9-bit (RX9 = 1): 1 = Enables address detection, enables interrupt and loads the receive buffer when RSR<8> is set 0 = Disables address detection, all bytes are received and ninth bit can be used as parity bit Asynchronous mode 9-bit (RX9 = 0): Don't care. bit 2 FERR: Framing Error bit 1 = Framing error (can be cleared by reading the RCREGx register and receiving the next valid byte) 0 = No framing error bit 1 OERR: Overrun Error bit 1 = Overrun error (can be cleared by clearing bit, CREN) 0 = No overrun error bit 0 RX9D: 9th bit of Received Data This can be address/data bit or a parity bit and must be calculated by user firmware. 2010 Microchip Technology Inc. DS39770C-page 259 PIC18F85J90 FAMILY 19.2 AUSART Baud Rate Generator (BRG) The BRG is a dedicated, 8-bit generator that supports both the Asynchronous and Synchronous modes of the AUSART. The SPBRG2 register controls the period of a free-running timer. In Asynchronous mode, bit BRGH (TXSTA<2>) also controls the baud rate. In Synchronous mode, BRGH is ignored. Table 19-1 shows the formula for computation of the baud rate for different AUSART modes, which only apply in Master mode (internally generated clock). Given the desired baud rate and FOSC, the nearest integer value for the SPBRG2 register can be calculated using the formulas in Table 19-1. From this, the error in baud rate can be determined. An example calculation is shown in Example 19-1. Typical baud rates and error values for the various Asynchronous modes are shown in Table 19-2. It may be advantageous to use the high baud rate (BRGH = 1) to reduce the baud rate error, or achieve a slow baud rate for a fast oscillator frequency. TABLE 19-1: Writing a new value to the SPBRG2 register causes the BRG timer to be reset (or cleared). This ensures the BRG does not wait for a timer overflow before outputting the new baud rate. 19.2.1 OPERATION IN POWER-MANAGED MODES The device clock is used to generate the desired baud rate. When one of the power-managed modes is entered, the new clock source may be operating at a different frequency. This may require an adjustment to the value in the SPBRG2 register. 19.2.2 SAMPLING The data on the RX2 pin is sampled three times by a majority detect circuit to determine if a high or a low level is present at the RX2 pin. BAUD RATE FORMULAS Configuration Bits BRG/AUSART Mode Baud Rate Formula 0 Asynchronous FOSC/[64 (n + 1)] 1 Asynchronous FOSC/[16 (n + 1)] x Synchronous FOSC/[4 (n + 1)] SYNC BRGH 0 0 1 Legend: x = Don't care, n = Value of SPBRG2 register EXAMPLE 19-1: CALCULATING BAUD RATE ERROR For a device with FOSC of 16 MHz, desired baud rate of 9600, Asynchronous mode, BRGH = 0: Desired Baud Rate = FOSC/(64 ([SPBRG2] + 1)) Solving for SPBRG2: X = ((FOSC/Desired Baud Rate)/64) - 1 = ((16000000/9600)/64) - 1 = [25.042] = 25 Calculated Baud Rate = 16000000/(64 (25 + 1)) = 9615 Error = (Calculated Baud Rate - Desired Baud Rate)/Desired Baud Rate = (9615 - 9600)/9600 = 0.16% TABLE 19-2: Name REGISTERS ASSOCIATED WITH THE BAUD RATE GENERATOR Bit 7 Bit 6 Bit 5 Bit 4 Bit 3 Bit 2 Bit 1 Bit 0 Reset Values on Page TXSTA2 CSRC TX9 TXEN SYNC -- BRGH TRMT TX9D 62 RCSTA2 SPEN RX9 SREN CREN ADDEN FERR OERR RX9D 62 SPBRG2 AUSART Baud Rate Generator Register 62 Legend: Shaded cells are not used by the BRG. DS39770C-page 260 2010 Microchip Technology Inc. PIC18F85J90 FAMILY TABLE 19-3: BAUD RATES FOR ASYNCHRONOUS MODES BRGH = 0 FOSC = 40.000 MHz FOSC = 20.000 MHz (decimal) Actual Rate (K) % Error -- -- -- 1.221 -- 1.73 1.73 255 2.404 0.16 64 9.766 19.531 1.73 31 57.6 56.818 -1.36 115.2 125.000 8.51 BAUD RATE (K) Actual Rate (K) % Error 0.3 1.2 -- -- -- -- 2.4 2.441 9.6 9.615 19.2 FOSC = 10.000 MHz (decimal) Actual Rate (K) % Error -- 255 -- 1.202 -- 0.16 0.16 129 2.404 1.73 31 9.766 19.531 1.73 15 10 62.500 8.51 4 104.167 -9.58 SPBRG value FOSC = 8.000 MHz (decimal) Actual Rate (K) % Error -- 129 -- 1.201 -- -0.16 -- 103 0.16 64 2.403 -0.16 51 1.73 15 9.615 -0.16 12 19.531 1.73 7 -- -- -- 4 52.083 -9.58 2 -- -- -- 2 78.125 -32.18 1 -- -- -- SPBRG value % Error SPBRG value SPBRG value SPBRG value (decimal) BRGH = 0 FOSC = 4.000 MHz FOSC = 2.000 MHz FOSC = 1.000 MHz (decimal) Actual Rate (K) % Error (decimal) Actual Rate (K) 207 0.300 -0.16 103 0.300 -0.16 51 0.16 51 1.201 -0.16 25 1.201 -0.16 12 2.404 0.16 25 2.403 -0.16 12 -- -- -- 8.929 -6.99 6 -- -- -- -- -- -- 19.2 20.833 8.51 2 -- -- -- -- -- -- 57.6 62.500 8.51 0 -- -- -- -- -- -- 115.2 62.500 -45.75 0 -- -- -- -- -- -- BAUD RATE (K) Actual Rate (K) % Error 0.3 0.300 0.16 1.2 1.202 2.4 9.6 SPBRG value SPBRG value (decimal) BRGH = 1 BAUD RATE (K) FOSC = 40.000 MHz FOSC = 20.000 MHz (decimal) Actual Rate (K) % Error -- -- -- -- -- -- -- -- -- Actual Rate (K) % Error 0.3 -- 1.2 -- 2.4 -- SPBRG value FOSC = 10.000 MHz (decimal) Actual Rate (K) % Error -- -- -- -- -- -- -- -- 2.441 SPBRG value FOSC = 8.000 MHz (decimal) Actual Rate (K) % Error -- -- -- -- -- -- -- -- -- 1.73 255 2.403 -0.16 207 SPBRG value SPBRG value (decimal) -- 9.6 9.766 1.73 255 9.615 0.16 129 9.615 0.16 64 9.615 -0.16 51 19.2 19.231 0.16 129 19.231 0.16 64 19.531 1.73 31 19.230 -0.16 25 57.6 58.140 0.94 42 56.818 -1.36 21 56.818 -1.36 10 55.555 3.55 8 115.2 113.636 -1.36 21 113.636 -1.36 10 125.000 8.51 4 -- -- -- BRGH = 1 BAUD RATE (K) FOSC = 4.000 MHz Actual Rate (K) % Error FOSC = 2.000 MHz SPBRG value (decimal) Actual Rate (K) % Error SPBRG value (decimal) FOSC = 1.000 MHz Actual Rate (K) % Error SPBRG value (decimal) 0.3 -- -- -- -- -- -- 0.300 -0.16 207 1.2 1.202 0.16 207 1.201 -0.16 103 1.201 -0.16 51 2.4 2.404 0.16 103 2.403 -0.16 51 2.403 -0.16 25 9.6 9.615 0.16 25 9.615 -0.16 12 -- -- -- 19.2 19.231 0.16 12 -- -- -- -- -- -- 57.6 62.500 8.51 3 -- -- -- -- -- -- 115.2 125.000 8.51 1 -- -- -- -- -- -- 2010 Microchip Technology Inc. DS39770C-page 261 PIC18F85J90 FAMILY 19.3 AUSART Asynchronous Mode Once the TXREG2 register transfers the data to the TSR register (occurs in one TCY), the TXREG2 register is empty and the TX2IF flag bit (PIR3<4>) is set. This interrupt can be enabled or disabled by setting or clearing the interrupt enable bit, TX2IE (PIE3<4>). TX2IF will be set regardless of the state of TX2IE; it cannot be cleared in software. TX2IF is also not cleared immediately upon loading TXREG2, but becomes valid in the second instruction cycle following the load instruction. Polling TX2IF immediately following a load of TXREG2 will return invalid results. The Asynchronous mode of operation is selected by clearing the SYNC bit (TXSTA2<4>). In this mode, the AUSART uses standard Non-Return-to-Zero (NRZ) format (one Start bit, eight or nine data bits and one Stop bit). The most common data format is 8 bits. An on-chip, dedicated, 8-bit Baud Rate Generator can be used to derive standard baud rate frequencies from the oscillator. The AUSART transmits and receives the LSb first. The AUSART's transmitter and receiver are functionally independent but use the same data format and baud rate. The Baud Rate Generator produces a clock, either x16 or x64 of the bit shift rate, depending on the BRGH bit (TXSTA2<2>). Parity is not supported by the hardware but can be implemented in software and stored as the 9th data bit. While TX2IF indicates the status of the TXREG2 register, another bit, TRMT (TXSTA2<1>), shows the status of the TSR register. TRMT is a read-only bit which is set when the TSR register is empty. No interrupt logic is tied to this bit so the user has to poll this bit in order to determine if the TSR register is empty. Note 1: The TSR register is not mapped in data memory so it is not available to the user. When operating in Asynchronous mode, the AUSART module consists of the following important elements: * * * * 2: Flag bit, TX2IF, is set when enable bit, TXEN, is set. Baud Rate Generator Sampling Circuit Asynchronous Transmitter Asynchronous Receiver 19.3.1 To set up an Asynchronous Transmission: 1. AUSART ASYNCHRONOUS TRANSMITTER 2. The AUSART transmitter block diagram is shown in Figure 19-1. The heart of the transmitter is the Transmit (Serial) Shift register (TSR). The Shift register obtains its data from the Read/Write Transmit Buffer register, TXREG2. The TXREG2 register is loaded with data in software. The TSR register is not loaded until the Stop bit has been transmitted from the previous load. As soon as the Stop bit is transmitted, the TSR is loaded with new data from the TXREG2 register (if available). 3. 4. 5. 6. 7. 8. FIGURE 19-1: Initialize the SPBRG2 register for the appropriate baud rate. Set or clear the BRGH bit, as required, to achieve the desired baud rate. Enable the asynchronous serial port by clearing bit, SYNC, and setting bit, SPEN. If interrupts are desired, set enable bit, TX2IE. If 9-bit transmission is desired, set transmit bit, TX9. Can be used as address/data bit. Enable the transmission by setting bit, TXEN, which will also set bit, TX2IF. If 9-bit transmission is selected, the ninth bit should be loaded in bit, TX9D. Load data to the TXREG2 register (starts transmission). If using interrupts, ensure that the GIE and PEIE bits in the INTCON register (INTCON<7:6>) are set. AUSART TRANSMIT BLOCK DIAGRAM Data Bus TX2IF TXREG2 Register TX2IE 8 MSb (8) LSb Pin Buffer and Control 0 TSR Register TX2 pin Interrupt TXEN Baud Rate CLK TRMT SPBRG2 Baud Rate Generator SPEN TX9 TX9D DS39770C-page 262 2010 Microchip Technology Inc. PIC18F85J90 FAMILY FIGURE 19-2: ASYNCHRONOUS TRANSMISSION Write to TXREG2 Word 1 BRG Output (Shift Clock) TX2 (pin) Start bit bit 0 bit 1 bit 7/8 Stop bit Word 1 TX2IF bit (Transmit Buffer Reg. Empty Flag) 1 TCY Word 1 Transmit Shift Reg TRMT bit (Transmit Shift Reg. Empty Flag) FIGURE 19-3: ASYNCHRONOUS TRANSMISSION (BACK TO BACK) Write to TXREG2 Word 2 Word 1 BRG Output (Shift Clock) TX2 (pin) Start bit bit 1 1 TCY TX2IF bit (Interrupt Reg. Flag) bit 7/8 Stop bit Start bit bit 0 Word 2 Word 1 1 TCY Word 1 Transmit Shift Reg. TRMT bit (Transmit Shift Reg. Empty Flag) Note: bit 0 Word 2 Transmit Shift Reg. This timing diagram shows two consecutive transmissions. TABLE 19-4: Name REGISTERS ASSOCIATED WITH ASYNCHRONOUS TRANSMISSION Bit 7 Bit 6 Bit 5 Bit 4 Bit 3 Bit 2 Bit 1 Bit 0 Reset Values on Page TMR0IE INT0IE RBIE TMR0IF INT0IF RBIF 57 PIR3 -- LCDIF RC2IF TX2IF -- CCP2IF CCP1IF -- 60 PIE3 -- LCDIE RC2IE TX2IE -- CCP2IE CCP1IE -- 60 IPR3 -- LCDIP RC2IP TX2IP -- CCP2IP CCP1IP -- 60 SPEN RX9 SREN CREN ADDEN FERR OERR RX9D 62 INTCON RCSTA2 TXREG2 TXSTA2 SPBRG2 LATG GIE/GIEH PEIE/GIEL AUSART Transmit Register CSRC TX9 62 TXEN SYNC -- BRGH TRMT TX9D AUSART Baud Rate Generator Register U2OD U1OD -- LATG4 62 62 LATG3 LATG2 LATG1 LATG0 60 Legend: -- = unimplemented locations read as `0'. Shaded cells are not used for asynchronous transmission. 2010 Microchip Technology Inc. DS39770C-page 263 PIC18F85J90 FAMILY 19.3.2 AUSART ASYNCHRONOUS RECEIVER 19.3.3 The receiver block diagram is shown in Figure 19-4. The data is received on the RX2 pin and drives the data recovery block. The data recovery block is actually a high-speed shifter operating at x16 times the baud rate, whereas the main receive serial shifter operates at the bit rate or at FOSC. This mode would typically be used in RS-232 systems. This mode would typically be used in RS-485 systems. To set up an Asynchronous Reception with Address Detect Enable: 1. Initialize the SPBRG2 register for the appropriate baud rate. Set or clear the BRGH and BRG16 bits, as required, to achieve the desired baud rate. 2. Enable the asynchronous serial port by clearing the SYNC bit and setting the SPEN bit. 3. If interrupts are required, set the RCEN bit and select the desired priority level with the RC2IP bit. 4. Set the RX9 bit to enable 9-bit reception. 5. Set the ADDEN bit to enable address detect. 6. Enable reception by setting the CREN bit. 7. The RC2IF bit will be set when reception is complete. The interrupt will be Acknowledged if the RC2IE and GIE bits are set. 8. Read the RCSTA2 register to determine if any error occurred during reception, as well as read bit 9 of data (if applicable). 9. Read RCREG2 to determine if the device is being addressed. 10. If any error occurred, clear the CREN bit. 11. If the device has been addressed, clear the ADDEN bit to allow all received data into the receive buffer and interrupt the CPU. To set up an Asynchronous Reception: 1. Initialize the SPBRG2 register for the appropriate baud rate. Set or clear the BRGH bit, as required, to achieve the desired baud rate. 2. Enable the asynchronous serial port by clearing bit, SYNC, and setting bit, SPEN. 3. If interrupts are desired, set enable bit, RC2IE. 4. If 9-bit reception is desired, set bit, RX9. 5. Enable the reception by setting bit, CREN. 6. Flag bit, RC2IF, will be set when reception is complete and an interrupt will be generated if enable bit, RC2IE, was set. 7. Read the RCSTA2 register to get the 9th bit (if enabled) and determine if any error occurred during reception. 8. Read the 8-bit received data by reading the RCREG2 register. 9. If any error occurred, clear the error by clearing enable bit, CREN. 10. If using interrupts, ensure that the GIE and PEIE bits in the INTCON register (INTCON<7:6>) are set. FIGURE 19-4: SETTING UP 9-BIT MODE WITH ADDRESS DETECT AUSART RECEIVE BLOCK DIAGRAM CREN OERR FERR x64 Baud Rate CLK SPBRG2 Baud Rate Generator 64 or 16 or 4 MSb Stop RSR Register (8) 7 1 LSb 0 Start RX9 Pin Buffer and Control Data Recovery RX2 RX9D RCREG2 Register FIFO SPEN 8 Interrupt RC2IF Data Bus RC2IE DS39770C-page 264 2010 Microchip Technology Inc. PIC18F85J90 FAMILY FIGURE 19-5: ASYNCHRONOUS RECEPTION Start bit bit 0 RX2 (pin) bit 1 Start bit bit 7/8 Stop bit Rcv Shift Reg Rcv Buffer Reg bit 0 Stop bit Start bit bit 7/8 Stop bit Word 2 RCREG2 Word 1 RCREG2 Read Rcv Buffer Reg RCREG2 bit 7/8 RC2IF (Interrupt Flag) OERR bit CREN Note: This timing diagram shows three words appearing on the RX2 input. The RCREG2 (Receive Buffer register) is read after the third word causing the OERR (Overrun) bit to be set. TABLE 19-5: Name INTCON REGISTERS ASSOCIATED WITH ASYNCHRONOUS RECEPTION Bit 7 Bit 6 Bit 5 GIE/GIEH PEIE/GIEL TMR0IE Bit 4 Bit 3 Bit 2 Bit 1 Bit 0 Reset Values on Page INT0IE RBIE TMR0IF INT0IF RBIF 57 PIR3 -- LCDIF RC2IF TX2IF -- CCP2IF CCP1IF -- 60 PIE3 -- LCDIE RC2IE TX2IE -- CCP2IE CCP1IE -- 60 -- LCDIP RC2IP TX2IP -- CCP2IP CCP1IP -- 60 SPEN RX9 SREN CREN ADDEN FERR OERR RX9D 62 SYNC -- BRGH TRMT TX9D IPR3 RCSTA2 RCREG2 TXSTA2 SPBRG2 AUSART Receive Register CSRC TX9 TXEN 62 AUSART Baud Rate Generator Register 62 62 Legend: -- = unimplemented locations read as `0'. Shaded cells are not used for asynchronous reception. 2010 Microchip Technology Inc. DS39770C-page 265 PIC18F85J90 FAMILY 19.4 AUSART Synchronous Master Mode Once the TXREG2 register transfers the data to the TSR register (occurs in one TCYCLE), the TXREG2 is empty and the TX2IF flag bit (PIR3<4>) is set. The interrupt can be enabled or disabled by setting or clearing the interrupt enable bit, TX2IE (PIE3<4>). TX2IF is set regardless of the state of enable bit, TX2IE; it cannot be cleared in software. It will reset only when new data is loaded into the TXREG2 register. The Synchronous Master mode is entered by setting the CSRC bit (TXSTA2<7>). In this mode, the data is transmitted in a half-duplex manner (i.e., transmission and reception do not occur at the same time). When transmitting data, the reception is inhibited and vice versa. Synchronous mode is entered by setting bit, SYNC (TXSTA2<4>). In addition, enable bit, SPEN (RCSTA2<7>), is set in order to configure the TX2 and RX2 pins to CK2 (clock) and DT2 (data) lines, respectively. While flag bit, TX2IF, indicates the status of the TXREG2 register, another bit, TRMT (TXSTA2<1>), shows the status of the TSR register. TRMT is a read-only bit which is set when the TSR is empty. No interrupt logic is tied to this bit so the user has to poll this bit in order to determine if the TSR register is empty. The TSR is not mapped in data memory so it is not available to the user. The Master mode indicates that the processor transmits the master clock on the CK2 line. 19.4.1 To set up a Synchronous Master Transmission: AUSART SYNCHRONOUS MASTER TRANSMISSION 1. The AUSART transmitter block diagram is shown in Figure 19-1. The heart of the transmitter is the Transmit (Serial) Shift register (TSR). The Shift register obtains its data from the Read/Write Transmit Buffer register, TXREG2. The TXREG2 register is loaded with data in software. The TSR register is not loaded until the last bit has been transmitted from the previous load. As soon as the last bit is transmitted, the TSR is loaded with new data from the TXREG2 (if available). 2. 3. 4. 5. 6. 7. 8. FIGURE 19-6: Initialize the SPBRG2 register for the appropriate baud rate. Enable the synchronous master serial port by setting bits, SYNC, SPEN and CSRC. If interrupts are desired, set enable bit, TX2IE. If 9-bit transmission is desired, set bit, TX9. Enable the transmission by setting bit, TXEN. If 9-bit transmission is selected, the ninth bit should be loaded in bit, TX9D. Start transmission by loading data to the TXREG2 register. If using interrupts, ensure that the GIE and PEIE bits in the INTCON register (INTCON<7:6>) are set. SYNCHRONOUS TRANSMISSION Q1 Q2 Q3Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1Q2 Q3 Q4 Q1 Q2 Q3 Q4 RX2/DT2 pin bit 0 bit 1 bit 2 Q3 Q4 Q1 Q2 Q3 Q4 Q1Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 bit 7 Word 1 bit 0 bit 1 bit 7 Word 2 TX2/CK2 pin Write to TXREG2 Reg Write Word 1 Write Word 2 TX2IF bit (Interrupt Flag) TRMT bit TXEN bit Note: `1' `1' Sync Master mode, SPBRG2 = 0; continuous transmission of two 8-bit words. DS39770C-page 266 2010 Microchip Technology Inc. PIC18F85J90 FAMILY FIGURE 19-7: SYNCHRONOUS TRANSMISSION (THROUGH TXEN) RX2/DT2 pin bit 0 bit 1 bit 2 bit 6 bit 7 TX2/CK2 pin Write to TXREG2 Reg TX2IF bit TRMT bit TXEN bit TABLE 19-6: Name INTCON REGISTERS ASSOCIATED WITH SYNCHRONOUS MASTER TRANSMISSION Bit 7 Bit 6 Bit 5 GIE/GIEH PEIE/GIEL TMR0IE Bit 4 Bit 3 Bit 2 Bit 1 Bit 0 Reset Values on Page INT0IE RBIE TMR0IF INT0IF RBIF 57 PIR3 -- LCDIF RC2IF TX2IF -- CCP2IF CCP1IF -- 60 PIE3 -- LCDIE RC2IE TX2IE -- CCP2IE CCP1IE -- 60 IPR3 -- LCDIP RC2IP TX2IP -- CCP2IP CCP1IP -- 60 SPEN RX9 SREN CREN ADDEN FERR OERR RX9D 62 RCSTA2 TXREG2 TXSTA2 SPBRG2 LATG AUSART Transmit Register CSRC TX9 62 TXEN SYNC -- BRGH TRMT TX9D AUSART Baud Rate Generator Register U2OD U1OD -- LATG4 62 62 LATG3 LATG2 LATG1 LATG0 60 Legend: -- = unimplemented, read as `0'. Shaded cells are not used for synchronous master transmission. 2010 Microchip Technology Inc. DS39770C-page 267 PIC18F85J90 FAMILY 19.4.2 AUSART SYNCHRONOUS MASTER RECEPTION 4. 5. 6. If interrupts are desired, set enable bit, RC2IE. If 9-bit reception is desired, set bit, RX9. If a single reception is required, set bit, SREN. For continuous reception, set bit, CREN. 7. Interrupt flag bit, RC2IF, will be set when reception is complete and an interrupt will be generated if the enable bit, RC2IE, was set. 8. Read the RCSTA2 register to get the 9th bit (if enabled) and determine if any error occurred during reception. 9. Read the 8-bit received data by reading the RCREG2 register. 10. If any error occurred, clear the error by clearing bit, CREN. 11. If using interrupts, ensure that the GIE and PEIE bits in the INTCON register (INTCON<7:6>) are set. Once Synchronous mode is selected, reception is enabled by setting either the Single Receive Enable bit, SREN (RCSTA2<5>), or the Continuous Receive Enable bit, CREN (RCSTA2<4>). Data is sampled on the RX2 pin on the falling edge of the clock. If enable bit SREN is set, only a single word is received. If enable bit CREN is set, the reception is continuous until CREN is cleared. If both bits are set, then CREN takes precedence. To set up a Synchronous Master Reception: 1. 2. 3. Initialize the SPBRG2 register for the appropriate baud rate. Enable the synchronous master serial port by setting bits, SYNC, SPEN and CSRC. Ensure bits, CREN and SREN, are clear. FIGURE 19-8: SYNCHRONOUS RECEPTION (MASTER MODE, SREN) Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 RX2/DT2 pin bit 0 bit 1 bit 2 bit 3 bit 4 bit 5 bit 6 bit 7 TX2/CK2 pin Write to bit SREN SREN bit CREN bit `0' `0' RC2IF bit (Interrupt) Read RCREG2 Note: Timing diagram demonstrates Sync Master mode with bit SREN = 1 and bit BRGH = 0. TABLE 19-7: Name INTCON REGISTERS ASSOCIATED WITH SYNCHRONOUS MASTER RECEPTION Bit 7 Bit 5 Bit 4 Bit 3 Bit 2 Bit 1 Bit 0 Reset Values on Page TMR0IE INT0IE RBIE TMR0IF INT0IF RBIF 57 Bit 6 GIE/GIEH PEIE/GIEL PIR3 -- LCDIF RC2IF TX2IF -- CCP2IF CCP1IF -- 60 PIE3 -- LCDIE RC2IE TX2IE -- CCP2IE CCP1IE -- 60 -- LCDIP RC2IP TX2IP -- CCP2IP CCP1IP -- 60 SPEN RX9 SREN CREN ADDEN FERR OERR RX9D 62 SYNC -- BRGH TRMT TX9D IPR3 RCSTA2 RCREG2 TXSTA2 SPBRG2 AUSART Receive Register CSRC TX9 TXEN 62 AUSART Baud Rate Generator Register 62 62 Legend: -- = unimplemented, read as `0'. Shaded cells are not used for synchronous master reception. DS39770C-page 268 2010 Microchip Technology Inc. PIC18F85J90 FAMILY 19.5 AUSART Synchronous Slave Mode Synchronous Slave mode is entered by clearing bit, CSRC (TXSTA2<7>). This mode differs from the Synchronous Master mode in that the shift clock is supplied externally at the CK2 pin (instead of being supplied internally in Master mode). This allows the device to transfer or receive data while in any low-power mode. 19.5.1 AUSART SYNCHRONOUS SLAVE TRANSMIT If two words are written to the TXREG2 and then the SLEEP instruction is executed, the following will occur: b) c) d) e) 1. 2. 3. 4. 5. 6. The operation of the Synchronous Master and Slave modes are identical except in the case of the Sleep mode. a) To set up a Synchronous Slave Transmission: 7. 8. Enable the synchronous slave serial port by setting bits, SYNC and SPEN, and clearing bit, CSRC. Clear bits, CREN and SREN. If interrupts are desired, set enable bit, TX2IE. If 9-bit transmission is desired, set bit, TX9. Enable the transmission by setting enable bit, TXEN. If 9-bit transmission is selected, the ninth bit should be loaded in bit, TX9D. Start transmission by loading data to the TXREG2 register. If using interrupts, ensure that the GIE and PEIE bits in the INTCON register (INTCON<7:6>) are set. The first word will immediately transfer to the TSR register and transmit. The second word will remain in the TXREG2 register. Flag bit, TX2IF, will not be set. When the first word has been shifted out of TSR, the TXREG2 register will transfer the second word to the TSR and flag bit, TX2IF, will now be set. If enable bit, TX2IE, is set, the interrupt will wake the chip from Sleep. If the global interrupt is enabled, the program will branch to the interrupt vector. TABLE 19-8: Name REGISTERS ASSOCIATED WITH SYNCHRONOUS SLAVE TRANSMISSION Bit 7 Bit 6 Bit 5 Bit 4 Bit 3 Bit 2 Bit 1 Bit 0 Reset Values on Page TMR0IE INT0IE RBIE TMR0IF INT0IF RBIF 57 PIR3 -- LCDIF RC2IF TX2IF -- CCP2IF CCP1IF -- 60 PIE3 -- LCDIE RC2IE TX2IE -- CCP2IE CCP1IE -- 60 IPR3 -- LCDIP RC2IP TX2IP -- CCP2IP CCP1IP -- 60 SPEN RX9 SREN CREN ADDEN FERR OERR RX9D 62 INTCON RCSTA2 TXREG2 TXSTA2 SPBRG2 LATG GIE/GIEH PEIE/GIEL AUSART Transmit Register CSRC TX9 62 TXEN SYNC -- BRGH TRMT TX9D AUSART Baud Rate Generator Register U2OD U1OD -- LATG4 62 62 LATG3 LATG2 LATG1 LATG0 60 Legend: -- = unimplemented, read as `0'. Shaded cells are not used for synchronous slave transmission. 2010 Microchip Technology Inc. DS39770C-page 269 PIC18F85J90 FAMILY 19.5.2 AUSART SYNCHRONOUS SLAVE RECEPTION To set up a Synchronous Slave Reception: 1. The operation of the Synchronous Master and Slave modes is identical except in the case of Sleep or any Idle mode, and bit SREN, which is a "don't care" in Slave mode. If receive is enabled by setting the CREN bit prior to entering Sleep, or any Idle mode, then a word may be received while in this low-power mode. Once the word is received, the RSR register will transfer the data to the RCREG2 register; if the RC2IE enable bit is set, the interrupt generated will wake the chip from low-power mode. If the global interrupt is enabled, the program will branch to the interrupt vector. Enable the synchronous master serial port by setting bits, SYNC and SPEN, and clearing bit, CSRC. If interrupts are desired, set enable bit, RC2IE. If 9-bit reception is desired, set bit, RX9. To enable reception, set enable bit, CREN. Flag bit, RC2IF, will be set when reception is complete. An interrupt will be generated if enable bit, RC2IE, was set. Read the RCSTA2 register to get the 9th bit (if enabled) and determine if any error occurred during reception. Read the 8-bit received data by reading the RCREG2 register. If any error occurred, clear the error by clearing bit, CREN. If using interrupts, ensure that the GIE and PEIE bits in the INTCON register (INTCON<7:6>) are set. 2. 3. 4. 5. 6. 7. 8. 9. TABLE 19-9: Name INTCON REGISTERS ASSOCIATED WITH SYNCHRONOUS SLAVE RECEPTION Bit 7 Bit 6 Bit 5 GIE/GIEH PEIE/GIEL TMR0IE Bit 4 Bit 3 Bit 2 Bit 1 Bit 0 Reset Values on Page INT0IE RBIE TMR0IF INT0IF RBIF 57 PIR3 -- LCDIF RC2IF TX2IF -- CCP2IF CCP1IF -- 60 PIE3 -- LCDIE RC2IE TX2IE -- CCP2IE CCP1IE -- 60 IPR3 -- LCDIP RC2IP TX2IP -- CCP2IP CCP1IP -- 60 SPEN RX9 SREN CREN ADDEN FERR OERR RX9D RCSTA2 RCREG2 TXSTA2 SPBRG2 AUSART Receive Register CSRC TX9 TXEN 62 62 SYNC -- BRGH TRMT TX9D AUSART Baud Rate Generator Register 62 62 Legend: -- = unimplemented, read as `0'. Shaded cells are not used for synchronous slave reception. DS39770C-page 270 2010 Microchip Technology Inc. PIC18F85J90 FAMILY 20.0 10-BIT ANALOG-TO-DIGITAL CONVERTER (A/D) MODULE The Analog-to-Digital (A/D) Converter module has 12 inputs for all PIC18F85J90 family devices. This module allows conversion of an analog input signal to a corresponding 10-bit digital number. The ADCON0 register, shown in Register 20-1, controls the operation of the A/D module. The ADCON1 register, shown in Register 20-2, configures the functions of the port pins. The ADCON2 register, shown in Register 20-3, configures the A/D clock source, programmed acquisition time and justification. The module has five registers: * * * * * A/D Result High Register (ADRESH) A/D Result Low Register (ADRESL) A/D Control Register 0 (ADCON0) A/D Control Register 1 (ADCON1) A/D Control Register 2 (ADCON2) REGISTER 20-1: ADCON0: A/D CONTROL REGISTER 0 R/W-0 U-0 R/W-0 R/W-0 R/W-0 R/W-0 R/W-0 R/W-0 ADCAL -- CHS3 CHS2 CHS1 CHS0 GO/DONE ADON bit 7 bit 0 Legend: R = Readable bit W = Writable bit U = Unimplemented bit, read as `0' -n = Value at POR `1' = Bit is set `0' = Bit is cleared bit 7 ADCAL: A/D Calibration bit 1 = Calibration is performed on next A/D conversion 0 = Normal A/D Converter operation (no calibration is performed) bit 6 Unimplemented: Read as `0' bit 5-2 CHS<3:0>: Analog Channel Select bits 0000 = Channel 00 (AN0) 0001 = Channel 01 (AN1) 0010 = Channel 02 (AN2) 0011 = Channel 03 (AN3) 0100 = Channel 04 (AN4) 0101 = Channel 05 (AN5) 0110 = Channel 06 (AN6) 0111 = Channel 07 (AN7) 1000 = Channel 08 (AN8) 1001 = Channel 09 (AN9) 1010 = Channel 10 (AN10) 1011 = Channel 11 (AN11) 11xx = Unused bit 1 GO/DONE: A/D Conversion Status bit When ADON = 1: 1 = A/D conversion in progress 0 = A/D Idle bit 0 ADON: A/D On bit 1 = A/D Converter module is enabled 0 = A/D Converter module is disabled 2010 Microchip Technology Inc. x = Bit is unknown DS39770C-page 271 PIC18F85J90 FAMILY REGISTER 20-2: ADCON1: A/D CONTROL REGISTER 1 U-0 U-0 R/W-0 R/W-0 R/W-0 R/W-0 R/W-0 R/W-0 -- -- VCFG1 VCFG0 PCFG3 PCFG2 PCFG1 PCFG0 bit 7 bit 0 Legend: R = Readable bit W = Writable bit U = Unimplemented bit, read as `0' -n = Value at POR `1' = Bit is set `0' = Bit is cleared bit 7-6 Unimplemented: Read as `0' bit 5 VCFG1: Voltage Reference Configuration bit (VREF- source) 1 = VREF- (AN2) 0 = AVSS bit 4 VCFG0: Voltage Reference Configuration bit (VREF+ source) 1 = VREF+ (AN3) 0 = AVDD bit 3-0 PCFG<3:0>: A/D Port Configuration Control bits: x = Bit is unknown PCFG<3:0> AN11 AN10 AN9 AN8 AN7 AN6 AN5 AN4 AN3 AN2 AN1 AN0 0000 A A A A A A A A A A A A 0001 A A A A A A A A A A A A 0010 A A A A A A A A A A A A 0011 A A A A A A A A A A A A 0100 D A A A A A A A A A A A 0101 D D A A A A A A A A A A 0110 D D D A A A A A A A A A 0111 D D D D A A A A A A A A 1000 D D D D D A A A A A A A 1001 D D D D D D A A A A A A 1010 D D D D D D D A A A A A 1011 D D D D D D D D A A A A 1100 D D D D D D D D D A A A 1101 D D D D D D D D D D A A 1110 D D D D D D D D D D D A 1111 D D D D D D D D D D D D A = Analog input DS39770C-page 272 D = Digital I/O 2010 Microchip Technology Inc. PIC18F85J90 FAMILY REGISTER 20-3: ADCON2: A/D CONTROL REGISTER 2 R/W-0 U-0 R/W-0 R/W-0 R/W-0 R/W-0 R/W-0 R/W-0 ADFM -- ACQT2 ACQT1 ACQT0 ADCS2 ADCS1 ADCS0 bit 7 bit 0 Legend: R = Readable bit W = Writable bit U = Unimplemented bit, read as `0' -n = Value at POR `1' = Bit is set `0' = Bit is cleared bit 7 ADFM: A/D Result Format Select bit 1 = Right justified 0 = Left justified bit 6 Unimplemented: Read as `0' bit 5-3 ACQT<2:0>: A/D Acquisition Time Select bits 111 = 20 TAD 110 = 16 TAD 101 = 12 TAD 100 = 8 TAD 011 = 6 TAD 010 = 4 TAD 001 = 2 TAD 000 = 0 TAD(1) bit 2-0 ADCS<2:0>: A/D Conversion Clock Select bits 111 = FRC (clock derived from A/D RC oscillator)(1) 110 = FOSC/64 101 = FOSC/16 100 = FOSC/4 011 = FRC (clock derived from A/D RC oscillator)(1) 010 = FOSC/32 001 = FOSC/8 000 = FOSC/2 Note 1: x = Bit is unknown If the A/D FRC clock source is selected, a delay of one TCY (instruction cycle) is added before the A/D clock starts. This allows the SLEEP instruction to be executed before starting a conversion. 2010 Microchip Technology Inc. DS39770C-page 273 PIC18F85J90 FAMILY The analog reference voltage is software selectable to either the device's positive and negative supply voltage (AVDD and AVSS), or the voltage level on the RA3/AN3/VREF+ and RA2/AN2/VREF- pins. the A/D conversion. When the A/D conversion is complete, the result is loaded into the ADRESH:ADRESL register pair, the GO/DONE bit (ADCON0<1>) is cleared and A/D Interrupt Flag bit, ADIF, is set. The A/D Converter has a unique feature of being able to operate while the device is in Sleep mode. To operate in Sleep, the A/D conversion clock must be derived from the A/D's internal RC oscillator. A device Reset forces all registers to their Reset state. This forces the A/D module to be turned off and any conversion in progress is aborted. The value in the ADRESH:ADRESL register pair is not modified for a Power-on Reset. These registers will contain unknown data after a Power-on Reset. The output of the sample and hold is the input into the converter, which generates the result via successive approximation. The block diagram of the A/D module is shown in Figure 20-1. Each port pin associated with the A/D Converter can be configured as an analog input or as a digital I/O. The ADRESH and ADRESL registers contain the result of FIGURE 20-1: A/D BLOCK DIAGRAM(1,2) CHS<3:0> 1011 1010 1001 1000 0111 0110 0101 (Input Voltage) AN8 AN7 AN6 AN5 0011 AN3 0001 0000 VDD Reference Voltage AN9 AN4 0010 VCFG<1:0> AN10 0100 VAIN 10-Bit A/D Converter AN11 AN2 AN1 AN0 VREF+ VREFVSS Note 1: Channels AN15 through AN12 are not available on 64-pin devices. 2: I/O pins have diode protection to VDD and VSS. DS39770C-page 274 2010 Microchip Technology Inc. PIC18F85J90 FAMILY After the A/D module has been configured as desired, the selected channel must be acquired before the conversion is started. The analog input channels must have their corresponding TRIS bits selected as an input. To determine acquisition time, see Section 20.1 "A/D Acquisition Requirements". After this acquisition time has elapsed, the A/D conversion can be started. An acquisition time can be programmed to occur between setting the GO/DONE bit and the actual start of the conversion. The following steps should be followed to do an A/D conversion: 1. 2. 3. 4. Wait the required acquisition time (if required). Start conversion: * Set GO/DONE bit (ADCON0<1>) Wait for A/D conversion to complete, by either: * Polling for the GO/DONE bit to be cleared 5. OR * Waiting for the A/D interrupt Read A/D Result registers (ADRESH:ADRESL); clear ADIF bit, if required. For next conversion, go to step 1 or step 2, as required. The A/D conversion time per bit is defined as TAD. A minimum wait of 2 TAD is required before next acquisition starts. 6. 7. Configure the A/D module: * Configure analog pins, voltage reference and digital I/O (ADCON1) * Select A/D input channel (ADCON0) * Select A/D acquisition time (ADCON2) * Select A/D conversion clock (ADCON2) * Turn on A/D module (ADCON0) Configure A/D interrupt (if desired): * Clear ADIF bit * Set ADIE bit * Set GIE bit FIGURE 20-2: ANALOG INPUT MODEL VDD RS VAIN ANx CPIN 5 pF Sampling Switch VT = 0.6V RIC 1k VT = 0.6V SS ILEAKAGE 100 nA RSS CHOLD = 25 pF VSS Legend: CPIN = Input Capacitance VT = Threshold Voltage ILEAKAGE = Leakage Current at the pin due to various junctions = Interconnect Resistance RIC = Sampling Switch SS = Sample/Hold Capacitance (from DAC) CHOLD RSS = Sampling Switch Resistance 2010 Microchip Technology Inc. VDD 1 2 3 4 Sampling Switch (k) DS39770C-page 275 PIC18F85J90 FAMILY 20.1 A/D Acquisition Requirements For the A/D Converter to meet its specified accuracy, the charge holding capacitor (CHOLD) must be allowed to fully charge to the input channel voltage level. The analog input model is shown in Figure 20-2. The source impedance (RS) and the internal sampling switch (RSS) impedance directly affect the time required to charge the capacitor CHOLD. The sampling switch (RSS) impedance varies over the device voltage (VDD). The source impedance affects the offset voltage at the analog input (due to pin leakage current). The maximum recommended impedance for analog sources is 2.5 k. After the analog input channel is selected (changed), the channel must be sampled for at least the minimum acquisition time before starting a conversion. Note: CHOLD Rs Conversion Error VDD Temperature = = = = 25 pF 2.5 k 1/2 LSb 3V Rss = 2 k 85C (system max.) ACQUISITION TIME = Amplifier Settling Time + Holding Capacitor Charging Time + Temperature Coefficient = TAMP + TC + TCOFF EQUATION 20-2: VHOLD or TC Equation 20-3 shows the calculation of the minimum required acquisition time, TACQ. This calculation is based on the following application system assumptions: When the conversion is started, the holding capacitor is disconnected from the input pin. EQUATION 20-1: TACQ To calculate the minimum acquisition time, Equation 20-1 may be used. This equation assumes that 1/2 LSb error is used (1024 steps for the A/D). The 1/2 LSb error is the maximum error allowed for the A/D to meet its specified resolution. A/D MINIMUM CHARGING TIME = (VREF - (VREF/2048)) * (1 - e(-TC/CHOLD(RIC + RSS + RS))) = -(CHOLD)(RIC + RSS + RS) ln(1/2048) EQUATION 20-3: CALCULATING THE MINIMUM REQUIRED ACQUISITION TIME TACQ = TAMP + TC + TCOFF TAMP = 0.2 s TCOFF = (Temp - 25C)(0.02 s/C) (85C - 25C)(0.02 s/C) 1.2 s Temperature coefficient is only required for temperatures > 25C. Below 25C, TCOFF = 0 ms. TC = -(CHOLD)(RIC + RSS + RS) ln(1/2048) s -(25 pF) (1 k + 2 k + 2.5 k) ln(0.0004883) s 1.05 s TACQ = 0.2 s + 1 s + 1.2 s 2.4 s DS39770C-page 276 2010 Microchip Technology Inc. PIC18F85J90 FAMILY 20.2 Selecting and Configuring Automatic Acquisition Time The ADCON2 register allows the user to select an acquisition time that occurs each time the GO/DONE bit is set. When the GO/DONE bit is set, sampling is stopped and a conversion begins. The user is responsible for ensuring the required acquisition time has passed between selecting the desired input channel and setting the GO/DONE bit. This occurs when the ACQT<2:0> bits (ADCON2<5:3>) remain in their Reset state (`000') and is compatible with devices that do not offer programmable acquisition times. If desired, the ACQT bits can be set to select a programmable acquisition time for the A/D module. When the GO/DONE bit is set, the A/D module continues to sample the input for the selected acquisition time, then automatically begins a conversion. Since the acquisition time is programmed, there may be no need to wait for an acquisition time between selecting a channel and setting the GO/DONE bit. In either case, when the conversion is completed, the GO/DONE bit is cleared, the ADIF flag is set and the A/D begins sampling the currently selected channel again. If an acquisition time is programmed, there is nothing to indicate if the acquisition time has ended or if the conversion has begun. 20.3 Selecting the A/D Conversion Clock The A/D conversion time per bit is defined as TAD. The A/D conversion requires 11 TAD per 10-bit conversion. The source of the A/D conversion clock is software selectable. There are seven possible options for TAD: * * * * * * * 2 TOSC 4 TOSC 8 TOSC 16 TOSC 32 TOSC 64 TOSC Internal RC Oscillator TABLE 20-1: TAD vs. DEVICE OPERATING FREQUENCIES AD Clock Source (TAD) Operation ADCS<2:0> Maximum Device Frequency 2 TOSC 000 2.86 MHz TOSC 100 5.71 MHz 8 TOSC 001 11.43 MHz 16 TOSC 101 22.86 MHz 32 TOSC 010 40.0 MHz 64 TOSC 110 40.0 MHz RC(2) x11 1.00 MHz(1) 4 Note 1: The RC source has a typical TAD time of 4 s. 2: For device frequencies above 1 MHz, the device must be in Sleep mode for the entire conversion or the A/D accuracy may be out of specification. 20.4 Configuring Analog Port Pins The ADCON1, TRISA, TRISF and TRISH registers control the operation of the A/D port pins. The port pins needed as analog inputs must have their corresponding TRIS bits set (input). If the TRIS bit is cleared (output), the digital output level (VOH or VOL) will be converted. The A/D operation is independent of the state of the CHS<3:0> bits and the TRIS bits. Note 1: When reading the PORT register, all pins configured as analog input channels will read as cleared (a low level). Pins configured as digital inputs will convert an analog input. Analog levels on a digitally configured input will be accurately converted. 2: Analog levels on any pin defined as a digital input may cause the digital input buffer to consume current out of the device's specification limits. For correct A/D conversions, the A/D conversion clock (TAD) must be as short as possible but greater than the minimum TAD (see parameter 130 in Table 26-25 for more information). Table 20-1 shows the resultant TAD times derived from the device operating frequencies and the A/D clock source selected. 2010 Microchip Technology Inc. DS39770C-page 277 PIC18F85J90 FAMILY 20.5 A/D Conversions 20.6 Figure 20-3 shows the operation of the A/D Converter after the GO/DONE bit has been set and the ACQT<2:0> bits are cleared. A conversion is started after the following instruction to allow entry into Sleep mode before the conversion begins. An A/D conversion can be started by the "Special Event Trigger" of the CCP2 module. This requires that the CCP2M<3:0> bits (CCP2CON<3:0>) be programmed as `1011' and that the A/D module is enabled (ADON bit is set). When the trigger occurs, the GO/DONE bit will be set, starting the A/D acquisition and conversion and the Timer1 (or Timer3) counter will be reset to zero. Timer1 (or Timer3) is reset to automatically repeat the A/D acquisition period with minimal software overhead (moving ADRESH/ADRESL to the desired location). The appropriate analog input channel must be selected and the minimum acquisition period is either timed by the user, or an appropriate TACQ time is selected before the Special Event Trigger sets the GO/DONE bit (starts a conversion). Figure 20-4 shows the operation of the A/D Converter after the GO/DONE bit has been set, the ACQT<2:0> bits are set to `010' and selecting a 4 TAD acquisition time before the conversion starts. Clearing the GO/DONE bit during a conversion will abort the current conversion. The A/D Result register pair will NOT be updated with the partially completed A/D conversion sample. This means the ADRESH:ADRESL registers will continue to contain the value of the last completed conversion (or the last value written to the ADRESH:ADRESL registers). If the A/D module is not enabled (ADON is cleared), the Special Event Trigger will be ignored by the A/D module but will still reset the Timer1 (or Timer3) counter. After the A/D conversion is completed or aborted, a 2 TAD wait is required before the next acquisition can be started. After this wait, acquisition on the selected channel is automatically started. Note: Use of the CCP2 Trigger The GO/DONE bit should NOT be set in the same instruction that turns on the A/D. FIGURE 20-3: A/D CONVERSION TAD CYCLES (ACQT<2:0> = 000, TACQ = 0) TCY - TAD TAD1 TAD2 TAD3 TAD4 TAD5 TAD6 TAD7 TAD8 TAD9 TAD10 TAD11 b4 b1 b0 b6 b7 b2 b9 b8 b3 b5 Conversion starts Holding capacitor is disconnected from analog input (typically 100 ns) Set GO/DONE bit Next Q4: ADRESH/ADRESL is loaded, GO/DONE bit is cleared, ADIF bit is set, holding capacitor is connected to analog input. A/D CONVERSION TAD CYCLES (ACQT<2:0> = 010, TACQ = 4 TAD) FIGURE 20-4: TAD Cycles TACQT Cycles 1 2 3 Automatic Acquisition Time 4 1 b9 3 4 5 b8 b7 b6 6 b5 7 b4 8 9 10 11 b3 b2 b1 b0 Conversion starts (Holding capacitor is disconnected) Set GO/DONE bit (Holding capacitor continues acquiring input) DS39770C-page 278 2 Next Q4: ADRESH:ADRESL is loaded, GO/DONE bit is cleared, ADIF bit is set, holding capacitor is reconnected to analog input. 2010 Microchip Technology Inc. PIC18F85J90 FAMILY 20.7 A/D Converter Calibration The A/D Converter in the PIC18F85J90 family of devices includes a self-calibration feature which compensates for any offset generated within the module. The calibration process is automated and is initiated by setting the ADCAL bit (ADCON0<7>). The next time the GO/DONE bit is set, the module will perform a "dummy" conversion (that is, with reading none of the input channels) and store the resulting value internally to compensate for offset. Thus, subsequent offsets will be compensated. The calibration process assumes that the device is in a relatively steady-state operating condition. If A/D calibration is used, it should be performed after each device Reset or if there are other major changes in operating conditions. 20.8 Operation in Power-Managed Modes The selection of the automatic acquisition time and A/D conversion clock is determined in part by the clock source and frequency while in a power-managed mode. TABLE 20-2: Name If the A/D is expected to operate while the device is in a power-managed mode, the ACQT<2:0> and ADCS<2:0> bits in ADCON2 should be updated in accordance with the power-managed mode clock that will be used. After the power-managed mode is entered (either of the power-managed Run modes), an A/D acquisition or conversion may be started. Once an acquisition or conversion is started, the device should continue to be clocked by the same power-managed mode clock source until the conversion has been completed. If desired, the device may be placed into the corresponding power-managed Idle mode during the conversion. If the power-managed mode clock frequency is less than 1 MHz, the A/D RC clock source should be selected. Operation in the Sleep mode requires the A/D RC clock to be selected. If bits ACQT<2:0> are set to `000' and a conversion is started, the conversion will be delayed one instruction cycle to allow execution of the SLEEP instruction and entry to Sleep mode. The IDLEN and SCS bits in the OSCCON register must have already been cleared prior to starting the conversion. SUMMARY OF A/D REGISTERS Bit 7 Bit 6 Bit 5 Bit 4 Bit 3 Bit 2 Bit 1 Bit 0 Reset Values on page TMR0IE INT0IE RBIE TMR0IF INT0IF RBIF 57 PIR1 -- ADIF RC1IF TX1IF SSPIF -- TMR2IF TMR1IF 60 PIE1 -- ADIE RC1IE TX1IE SSPIE -- TMR2IE TMR1IE 60 IPR1 -- ADIP RC1IP TX1IP SSPIP -- TMR2IP TMR1IP 60 PIR3 -- LCDIF RC2IF TX2IF -- CCP2IF CCP1IF -- 60 PIE3 -- LCDIE RC2IE TX2IE -- CCP2IE CCP1IE -- 60 -- LCDIP RC2IP TX2IP -- CCP2IP CCP1IP -- 60 INTCON IPR3 GIE/GIEH PEIE/GIEL ADRESH A/D Result Register High Byte ADRESL A/D Result Register Low Byte ADCAL -- ADCON1 -- ADCON2 ADFM ADCON0 CCP2CON PORTA TRISA 59 59 CHS3 CHS3 CHS1 CHS0 GO/DONE ADON 59 -- VCFG1 VCFG0 PCFG3 PCFG2 PCFG1 PCFG0 59 -- ACQT2 ACQT1 ACQT0 ADCS2 ADCS1 ADCS0 59 -- -- DC2B1 DC2B0 CCP2M3 CCP2M2 CCP2M1 CCP2M0 61 RA7(1) RA6(1) RA5 RA4 RA3 RA2 RA1 RA0 61 TRISA7 (1) TRISA6 (1) TRISA5 TRISA4 TRISA3 TRISA2 TRISA1 TRISA0 60 PORTF RF7 RF6 RF5 RF4 RF3 RF2 RF1 -- 60 TRISF TRISF5 TRISF4 TRISF5 TRISF4 TRISF3 TRISF2 TRISF1 -- 60 Legend: -- = unimplemented, read as `0'. Shaded cells are not used for A/D conversion. Note 1: RA6/RA7 and their associated latch and direction bits are configured as port pins only when the internal oscillator is selected as the default clock source (FOSC2 Configuration bit = 0); otherwise, they are disabled and these bits read as `0'. 2010 Microchip Technology Inc. DS39770C-page 279 PIC18F85J90 FAMILY NOTES: DS39770C-page 280 2010 Microchip Technology Inc. PIC18F85J90 FAMILY 21.0 COMPARATOR MODULE The analog comparator module contains two comparators that can be configured in a variety of ways. The inputs can be selected from the analog inputs multiplexed with pins RF1 through RF6, as well as the on-chip voltage reference (see Section 22.0 "Comparator Voltage Reference Module"). The digital outputs (normal or inverted) are available at the pin level and can also be read through the control register. REGISTER 21-1: The CMCON register (Register 21-1) selects the comparator input and output configuration. Block diagrams of the various comparator configurations are shown in Figure 21-1. CMCON: COMPARATOR MODULE CONTROL REGISTER R-0 R-0 R/W-0 R/W-0 R/W-0 R/W-1 R/W-1 R/W-1 C2OUT C1OUT C2INV C1INV CIS CM2 CM1 CM0 bit 7 bit 0 Legend: R = Readable bit W = Writable bit U = Unimplemented bit, read as `0' -n = Value at POR `1' = Bit is set `0' = Bit is cleared bit 7 C2OUT: Comparator 2 Output bit When C2INV = 0: 1 = C2 VIN+ > C2 VIN0 = C2 VIN+ < C2 VINWhen C2INV = 1: 1 = C2 VIN+ < C2 VIN0 = C2 VIN+ > C2 VIN- bit 6 C1OUT: Comparator 1 Output bit When C1INV = 0: 1 = C1 VIN+ > C1 VIN0 = C1 VIN+ < C1 VINWhen C1INV = 1: 1 = C1 VIN+ < C1 VIN0 = C1 VIN+ > C1 VIN- bit 5 C2INV: Comparator 2 Output Inversion bit 1 = C2 output inverted 0 = C2 output not inverted bit 4 C1INV: Comparator 1 Output Inversion bit 1 = C1 output inverted 0 = C1 output not inverted bit 3 CIS: Comparator Input Switch bit When CM<2:0> = 110: 1 = C1 VIN- connects to RF5/AN10/CVREF C2 VIN- connects to RF3/AN8 0 = C1 VIN- connects to RF6/AN11 C2 VIN- connects to RF4/AN9 bit 2-0 CM<2:0>: Comparator Mode bits Figure 21-1 shows the Comparator modes and the CM<2:0> bit settings. 2010 Microchip Technology Inc. x = Bit is unknown DS39770C-page 281 PIC18F85J90 FAMILY 21.1 Comparator Configuration There are eight modes of operation for the comparators, shown in Figure 21-1. Bits, CM<2:0> of the CMCON register, are used to select these modes. The TRISF register controls the data direction of the comparator pins for each mode. If the Comparator FIGURE 21-1: RF4/AN9/ SEG22 RF3/AN8/ SEG21 A A RF4/AN9/ SEG22 RF3/AN8/ SEG21 Comparator interrupts should be disabled during a Comparator mode change; otherwise, a false interrupt may occur. Comparators Off (POR Default Value) CM<2:0> = 111 C1 Off (Read as `0') RF6/AN11/ D SEG24 RF5/AN10/ D CVREF/SEG23 C2 Off (Read as `0') RF4/AN9/ SEG22 RF3/AN8/ SEG21 VINVIN+ VINVIN+ Two Independent Comparators CM<2:0> = 010 RF6/AN11/ A SEG24 RF5/AN10/ A CVREF/SEG23 Note: COMPARATOR I/O OPERATING MODES Comparator Outputs Disabled CM<2:0> = 000 RF6/AN11/ A SEG24 RF5/AN10/ A CVREF/SEG23 mode is changed, the comparator output level may not be valid for the specified mode change delay shown in Section 26.0 "Electrical Characteristics". A VIN- A VIN+ VIN+ D VIN- D VIN+ C1 Off (Read as `0') C2 Off (Read as `0') Two Independent Comparators with Outputs CM<2:0> = 011 VINVIN+ VIN- C1 C1OUT C2 C2OUT VINRF6/AN11/ A SEG24 C1 V IN+ RF5/AN10/ A CVREF/SEG23 RF2/AN7/C1OUT*/SEG20 RF4/AN9/ SEG22 RF3/AN8/ SEG21 A VIN- A VIN+ C1OUT C2OUT C2 RF1/AN6/C2OUT*/SEG19 Two Common Reference Comparators CM<2:0> = 100 RF6/AN11/ A SEG24 RF5/AN10/ A CVREF/SEG23 VIN+ RF4/AN9/ SEG22 A VIN- RF3/AN8/ SEG21 D VIN+ Two Common Reference Comparators with Outputs CM<2:0> = 101 VIN- C1 C1OUT A RF6/AN11/ SEG24 A RF5/AN10/ CVREF/SEG23 VINVIN+ C1 C1OUT C2 C2OUT RF2/AN7/C1OUT*/ SEG20 C2 C2OUT RF4/AN9/ SEG22 RF3/AN8/ SEG21 A VIN- D VIN+ RF1/AN6/C2OUT*/SEG19 One Independent Comparator with Output CM<2:0> = 001 RF6/AN11/ A SEG24 RF5/AN10/ A CVREF/SEG23 VINVIN+ C1 C1OUT RF2/AN7/C1OUT*/SEG20 RF4/AN9/ SEG22 RF3/AN8/ SEG21 D VIN- D VIN+ Four Inputs Multiplexed to Two Comparators CM<2:0> = 110 RF6/AN11/ A SEG24 RF5/AN10/ A CVREF/SEG23 RF4/AN9/ SEG22 RF3/AN8/ SEG21 C2 Off (Read as `0') CIS = 0 CIS = 1 VIN- CIS = 0 CIS = 1 VIN- VIN+ C1 C1OUT C2 C2OUT A A VIN+ CVREF From VREF module A = Analog Input, port reads zeros always D = Digital Input CIS (CMCON<3>) is the Comparator Input Switch * Setting the TRISF<2:1> bits will disable the comparator outputs by configuring the pins as inputs. DS39770C-page 282 2010 Microchip Technology Inc. PIC18F85J90 FAMILY 21.2 Comparator Operation 21.3.2 A single comparator is shown in Figure 21-2, along with the relationship between the analog input levels and the digital output. When the analog input at VIN+ is less than the analog input VIN-, the output of the comparator is a digital low level. When the analog input at VIN+ is greater than the analog input VIN-, the output of the comparator is a digital high level. The shaded areas of the output of the comparator in Figure 21-2 represent the uncertainty due to input offsets and response time. 21.3 Comparator Reference Depending on the comparator operating mode, either an external or internal voltage reference may be used. The analog signal present at VIN- is compared to the signal at VIN+ and the digital output of the comparator is adjusted accordingly (Figure 21-2). FIGURE 21-2: SINGLE COMPARATOR VIN+ + VIN- - Output VINVIN+ Output 21.3.1 INTERNAL REFERENCE SIGNAL The comparator module also allows the selection of an internally generated voltage reference from the comparator voltage reference module. This module is described in more detail in Section 22.0 "Comparator Voltage Reference Module". The internal reference is only available in the mode where four inputs are multiplexed to two comparators (CM<2:0> = 110). In this mode, the internal voltage reference is applied to the VIN+ pin of both comparators. 21.4 Comparator Response Time Response time is the minimum time, after selecting a new reference voltage or input source, before the comparator output has a valid level. If the internal reference is changed, the maximum delay of the internal voltage reference must be considered when using the comparator outputs; otherwise, the maximum delay of the comparators should be used (see Section 26.0 "Electrical Characteristics"). 21.5 Comparator Outputs The comparator outputs are read through the CMCON register. These bits are read-only. The comparator outputs may also be directly output to the RF1 and RF2 I/O pins. When enabled, multiplexors in the output path of the RF1 and RF2 pins will switch and the output of each pin will be the unsynchronized output of the comparator. The uncertainty of each of the comparators is related to the input offset voltage and the response time given in the specifications. Figure 21-3 shows the comparator output block diagram. The TRISF bits will still function as an output enable/ disable for the RF1 and RF2 pins while in this mode. EXTERNAL REFERENCE SIGNAL When external voltage references are used, the comparator module can be configured to have the comparators operate from the same or different reference sources. However, threshold detector applications may require the same reference. The reference signal must be between VSS and VDD and can be applied to either pin of the comparator(s). 2010 Microchip Technology Inc. The polarity of the comparator outputs can be changed using the C2INV and C1INV bits (CMCON<5:4>). Note 1: When reading the PORT register, all pins configured as analog inputs will read as `0'. Pins configured as digital inputs will convert an analog input according to the Schmitt Trigger input specification. 2: Analog levels on any pin defined as a digital input may cause the input buffer to consume more current than is specified. DS39770C-page 283 PIC18F85J90 FAMILY + COMPARATOR OUTPUT BLOCK DIAGRAM To RF1 or RF2 Pin - Port Pins MULTIPLEX FIGURE 21-3: D Q Bus Data CxINV Read CMCON EN D Q EN CL From Other Comparator Reset 21.6 Comparator Interrupts The comparator interrupt flag is set whenever there is a change in the output value of either comparator. Software will need to maintain information about the status of the output bits, as read from CMCON<7:6>, to determine the actual change that occurred. The CMIF bit (PIR2<6>) is the Comparator Interrupt Flag. The CMIF bit must be reset by clearing it. Since it is also possible to write a `1' to this register, a simulated interrupt may be initiated. Both the CMIE bit (PIE2<6>) and the PEIE bit (INTCON<6>) must be set to enable the interrupt. In addition, the GIE bit (INTCON<7>) must also be set. If any of these bits are clear, the interrupt is not enabled, though the CMIF bit will still be set if an interrupt condition occurs. Note: If a change in the CMCON register (C1OUT or C2OUT) should occur when a read operation is being executed (start of the Q2 cycle), then the CMIF (PIR2<6>) interrupt flag may not get set. The user, in the Interrupt Service Routine, can clear the interrupt in the following manner: a) b) Set CMIF bit 21.7 Comparator Operation During Sleep When a comparator is active and the device is placed in Sleep mode, the comparator remains active and the interrupt is functional, if enabled. This interrupt will wake-up the device from Sleep mode, when enabled. Each operational comparator will consume additional current, as shown in the comparator specifications. To minimize power consumption while in Sleep mode, turn off the comparators (CM<2:0> = 111) before entering Sleep. If the device wakes up from Sleep, the contents of the CMCON register are not affected. 21.8 Effects of a Reset A device Reset forces the CMCON register to its Reset state, causing the comparator modules to be turned off (CM<2:0> = 111). However, the input pins (RF3 through RF6) are configured as analog inputs by default on device Reset. The I/O configuration for these pins is determined by the setting of the PCFG<3:0> bits (ADCON1<3:0>). Therefore, device current is minimized when analog inputs are present at Reset time. Any read or write of CMCON will end the mismatch condition. Clear flag bit, CMIF. A mismatch condition will continue to set flag bit CMIF. Reading CMCON will end the mismatch condition and allow flag bit CMIF to be cleared. DS39770C-page 284 2010 Microchip Technology Inc. PIC18F85J90 FAMILY 21.9 Analog Input Connection Considerations range by more than 0.6V in either direction, one of the diodes is forward biased and a latch-up condition may occur. A maximum source impedance of 10 k is recommended for the analog sources. Any external component connected to an analog input pin, such as a capacitor or a Zener diode, should have very little leakage current. A simplified circuit for an analog input is shown in Figure 21-4. Since the analog pins are connected to a digital output, they have reverse biased diodes to VDD and VSS. The analog input, therefore, must be between VSS and VDD. If the input voltage deviates from this FIGURE 21-4: COMPARATOR ANALOG INPUT MODEL VDD VT = 0.6V RS < 10k RIC Comparator Input AIN CPIN 5 pF VA VT = 0.6V ILEAKAGE 500 nA VSS Legend: TABLE 21-1: Name INTCON CPIN VT ILEAKAGE RIC RS VA = = = = = = Input Capacitance Threshold Voltage Leakage Current at the pin due to various junctions Interconnect Resistance Source Impedance Analog Voltage REGISTERS ASSOCIATED WITH COMPARATOR MODULE Bit 7 Bit 6 GIE/GIEH PEIE/GIEL Bit 5 Bit 4 Bit 3 Bit 2 Bit 1 Bit 0 Reset Values on page TMR0IE INT0IE RBIE TMR0IF INT0IF RBIF 57 PIR2 OSCFIF CMIF -- -- BCLIF LVDIF TMR3IF -- 60 PIE2 OSCFIE CMIE -- -- BCLIE LVDIE TMR3IE -- 60 IPR2 OSCFIP CMIP -- -- BCLIP LVDIP TMR3IP -- 60 CMCON C2OUT C1OUT C2INV C1INV CIS CM2 CM1 CM0 59 CVRCON CVREN CVROE CVRR CVRSS CVR3 CVR2 CVR1 CVR0 59 RF7 RF6 RF5 RF4 RF3 RF2 RF1 -- 60 PORTF LATF LATF7 LATF6 LATF5 LATF4 LATF3 LATF2 LATF1 -- 60 TRISF TRISF7 TRISF6 TRISF5 TRISF4 TRISF3 TRISF2 TRISF1 -- 60 Legend: -- = unimplemented, read as `0'. Shaded cells are unused by the comparator module. 2010 Microchip Technology Inc. DS39770C-page 285 PIC18F85J90 FAMILY NOTES: DS39770C-page 286 2010 Microchip Technology Inc. PIC18F85J90 FAMILY 22.0 COMPARATOR VOLTAGE REFERENCE MODULE The comparator voltage reference is a 16-tap resistor ladder network that provides a selectable reference voltage. Although its primary purpose is to provide a reference for the analog comparators, it may also be used independently of them. A block diagram of the module is shown in Figure 22-1. The resistor ladder is segmented to provide two ranges of CVREF values and has a power-down function to conserve power when the reference is not being used. The module's supply reference can be provided from either device VDD/VSS or an external voltage reference. 22.1 Configuring the Comparator Voltage Reference The comparator voltage reference module is controlled through the CVRCON register (Register 22-1). The comparator voltage reference provides two ranges of output voltage, each with 16 distinct levels. REGISTER 22-1: The range to be used is selected by the CVRR bit (CVRCON<5>). The primary difference between the ranges is the size of the steps selected by the CVREF Selection bits (CVR<3:0>), with one range offering finer resolution. The equations used to calculate the output of the comparator voltage reference are as follows: If CVRR = 1: CVREF = ((CVR<3:0>)/24) x (CVRSRC) If CVRR = 0: CVREF = (CVRSRC/4) + ((CVR<3:0>)/32) x (CVRSRC) The comparator reference supply voltage can come from either VDD and VSS, or the external VREF+ and VREF- that are multiplexed with RA2 and RA3. The voltage source is selected by the CVRSS bit (CVRCON<4>). The settling time of the comparator voltage reference must be considered when changing the CVREF output (see Table 26-3 in Section 26.0 "Electrical Characteristics"). CVRCON: COMPARATOR VOLTAGE REFERENCE CONTROL REGISTER R/W-0 R/W-0 R/W-0 R/W-0 R/W-0 R/W-0 R/W-0 R/W-0 CVREN CVROE(1) CVRR CVRSS CVR3 CVR2 CVR1 CVR0 bit 7 bit 0 Legend: R = Readable bit W = Writable bit U = Unimplemented bit, read as `0' -n = Value at POR `1' = Bit is set `0' = Bit is cleared x = Bit is unknown bit 7 CVREN: Comparator Voltage Reference Enable bit 1 = CVREF circuit powered on 0 = CVREF circuit powered down bit 6 CVROE: Comparator VREF Output Enable bit(1) 1 = CVREF voltage level is also output on the RF5/AN10/CVREF/SEG23 pin 0 = CVREF voltage is disconnected from the RF5/AN10/CVREF/SEG23 pin bit 5 CVRR: Comparator VREF Range Selection bit 1 = 0 to 0.667 CVRSRC, with CVRSRC/24 step size (low range) 0 = 0.25 CVRSRC to 0.75 CVRSRC, with CVRSRC/32 step size (high range) bit 4 CVRSS: Comparator VREF Source Selection bit 1 = Comparator reference source, CVRSRC = (VREF+) - (VREF-) 0 = Comparator reference source, CVRSRC = VDD - VSS bit 3-0 CVR3:CVR0: Comparator VREF Value Selection bits (0 (CVR<3:0>) 15) When CVRR = 1: CVREF = ((CVR<3:0>)/24) (CVRSRC) When CVRR = 0: CVREF = (CVRSRC/4) + ((CVR<3:0>)/32) (CVRSRC) Note 1: CVROE overrides the TRISF<5> bit setting. 2010 Microchip Technology Inc. DS39770C-page 287 PIC18F85J90 FAMILY FIGURE 22-1: COMPARATOR VOLTAGE REFERENCE BLOCK DIAGRAM VREF+ VDD CVRSS = 1 8R CVRSS = 0 CVR<3:0> R CVREN R R 16-to-1 MUX R 16 Steps R CVREF R R CVRR VREF- 8R CVRSS = 1 CVRSS = 0 22.2 Voltage Reference Accuracy/Error The full range of voltage reference cannot be realized due to the construction of the module. The transistors on the top and bottom of the resistor ladder network (Figure 22-1) keep CVREF from approaching the reference source rails. The voltage reference is derived from the reference source; therefore, the CVREF output changes with fluctuations in that source. The tested absolute accuracy of the voltage reference can be found in Section 26.0 "Electrical Characteristics". 22.3 Operation During Sleep When the device wakes up from Sleep through an interrupt or a Watchdog Timer time-out, the contents of the CVRCON register are not affected. To minimize current consumption in Sleep mode, the voltage reference should be disabled. 22.4 Effects of a Reset A device Reset disables the voltage reference by clearing bit, CVREN (CVRCON<7>). This Reset also disconnects the reference from the RA2 pin by clearing bit, CVROE (CVRCON<6>) and selects the high-voltage range by clearing bit, CVRR (CVRCON<5>). The CVR value select bits are also cleared. 22.5 Connection Considerations The voltage reference module operates independently of the comparator module. The output of the reference generator may be connected to the RF5 pin if the CVROE bit is set. Enabling the voltage reference output onto RA2 when it is configured as a digital input will increase current consumption. Connecting RF5 as a digital output with CVRSS enabled will also increase current consumption. The RF5 pin can be used as a simple D/A output with limited drive capability. Due to the limited current drive capability, a buffer must be used on the voltage reference output for external connections to VREF. Figure 22-2 shows an example buffering technique. DS39770C-page 288 2010 Microchip Technology Inc. PIC18F85J90 FAMILY FIGURE 22-2: COMPARATOR VOLTAGE REFERENCE OUTPUT BUFFER EXAMPLE PIC18F85J90 CVREF Module R(1) Voltage Reference Output Impedance Note 1: TABLE 22-1: Name CVRCON + - RF5 CVREF Output R is dependent upon the Comparator Voltage Reference bits, CVRCON<5> and CVRCON<3:0>. REGISTERS ASSOCIATED WITH COMPARATOR VOLTAGE REFERENCE Bit 7 Bit 6 Bit 5 Bit 4 Bit 3 Bit 2 Bit 1 Bit 0 Reset Values on page CVREN CVROE CVRR CVRSS CVR3 CVR2 CVR1 CVR0 59 CMCON C2OUT C1OUT C2INV C1INV CIS CM2 CM1 CM0 59 TRISF TRISF7 TRISF6 TRISF5 TRISF4 TRISF3 TRISF2 TRISF1 -- 60 Legend: -- = unimplemented, read as `0'. Shaded cells are not used with the comparator voltage reference. 2010 Microchip Technology Inc. DS39770C-page 289 PIC18F85J90 FAMILY NOTES: DS39770C-page 290 2010 Microchip Technology Inc. PIC18F85J90 FAMILY 23.0 SPECIAL FEATURES OF THE CPU PIC18F85J90 family devices include several features intended to maximize reliability and minimize cost through elimination of external components. These are: * Oscillator Selection * Resets: - Power-on Reset (POR) - Power-up Timer (PWRT) - Oscillator Start-up Timer (OST) - Brown-out Reset (BOR) * Interrupts * Watchdog Timer (WDT) * Fail-Safe Clock Monitor * Two-Speed Start-up * Code Protection * In-Circuit Serial Programming The oscillator can be configured for the application depending on frequency, power, accuracy and cost. All of the options are discussed in detail in Section 3.0 "Oscillator Configurations". A complete discussion of device Resets and interrupts is available in previous sections of this data sheet. In addition to their Power-up and Oscillator Start-up Timers provided for Resets, the PIC18F85J90 family family of devices have a configurable Watchdog Timer which is controlled in software. The inclusion of an internal RC oscillator also provides the additional benefits of a Fail-Safe Clock Monitor (FSCM) and Two-Speed Start-up. FSCM provides for background monitoring of the peripheral clock and automatic switchover in the event of its failure. Two-Speed Start-up enables code to be executed almost immediately on start-up, while the primary clock source completes its start-up delays. All of these features are enabled and configured by setting the appropriate Configuration register bits. 23.1 Configuration Bits The Configuration bits can be programmed (read as `0'), or left unprogrammed (read as `1'), to select various device configurations. These bits are mapped starting at program memory location 300000h. A complete list is shown in Table 23-2. A detailed explanation of the various bit functions is provided in Register 23-1 through Register 23-5. 23.1.1 CONSIDERATIONS FOR CONFIGURING THE PIC18F85J90 FAMILY DEVICES Unlike some previous PIC18 microcontrollers, PIC18F85J90 family devices do not use persistent memory registers to store configuration information. The Configuration registers, CONFIG1L through CONFIG4H, are implemented as volatile memory. Immediately after power-up, or after a device Reset, the microcontroller hardware automatically loads the CONFIG1L through CONFIG4L registers with configuration data stored in nonvolatile Flash program memory. The last four words of Flash program memory, known as the Flash Configuration Words (FCW), are used to store the configuration data. Table 23-1 provides the Flash program memory mapping, which will be loaded into the corresponding Configuration register. When creating applications for these devices, users should always specifically allocate the location of the Flash Configuration Word for configuration data. This is to make certain that program code is not stored in this address when the code is compiled. The volatile memory cells used for the Configuration bits always reset to `1' on Power-on Resets. For all other types of Reset events, the previously programmed values are maintained and used without reloading from program memory. The four Most Significant bits of CONFIG1H, CONFIG2H and CONFIG3H in program memory should also be `1111'. This makes these Configuration Words appear to be NOP instructions in the remote event that their locations are ever executed by accident. Since Configuration bits are not implemented in the corresponding locations, writing `1's to these locations has no effect on device operation. To prevent inadvertent configuration changes during code execution, all programmable Configuration bits are write-once. After a bit is initially programmed during a power cycle, it cannot be written to again. Changing a device configuration requires that power to the device be cycled. TABLE 23-1: Configuration Byte MAPPING OF THE FLASH CONFIGURATION WORDS TO THE CONFIGURATION REGISTERS Code Space Address Configuration Register Address CONFIG1L XXXF8h 300000h CONFIG1H XXXF9h 300001h CONFIG2L XXXFAh 300002h CONFIG2H XXXFBh 300003h CONFIG3L XXXFCh 300004h CONFIG3H XXXFDh 300005h Legend: Unimplemented in PIC18F85J90 family devices. 2010 Microchip Technology Inc. DS39770C-page 291 PIC18F85J90 FAMILY TABLE 23-2: CONFIGURATION BITS AND DEVICE IDs File Name 300000h CONFIG1L Default/ Unprogrammed Value(1) Bit 7 Bit 6 Bit 5 Bit 4 Bit 3 Bit 2 Bit 1 Bit 0 DEBUG XINST STVREN -- -- -- -- WDTEN 111- ---1 (2) (2) (2) (2) (3) 300001h CONFIG1H -- 300002h CONFIG2L IESO FCMEN -- -- 300003h CONFIG2H --(2) --(2) --(2) --(2) 300005h CONFIG3H --(2) --(2) --(2) --(2) -- -- -- CCP2MX 3FFFFEh DEVID1 DEV2 DEV1 DEV0 REV4 REV3 REV2 REV1 REV0 xxxx xxxx(4) 3FFFFFh DEVID2 DEV10 DEV9 DEV8 DEV7 DEV6 DEV5 DEV4 DEV3 0000 10x1(4) Legend: Note 1: 2: 3: 4: -- -- -- -- -- CP0 -- -- ---- 01-- FOSC2 FOSC1 FOSC0 11-- -111 WDTPS3 WDTPS2 WDTPS1 WDTPS0 ---- 1111 ---- ---1 x = unknown, - = unimplemented. Shaded cells are unimplemented, read as `0'. Values reflect the unprogrammed state as received from the factory and following Power-on Resets. In all other Reset states, the configuration bytes maintain their previously programmed states. The value of these bits in program memory should always be `1'. This ensures that the location is executed as a NOP if it is accidentally executed. This bit should always be maintained as `0'. See Register 23-6 and Register 23-7 for DEVID values. These registers are read-only and cannot be programmed by the user. DS39770C-page 292 2010 Microchip Technology Inc. PIC18F85J90 FAMILY REGISTER 23-1: CONFIG1L: CONFIGURATION REGISTER 1 LOW (BYTE ADDRESS 300000h) R/WO-1 R/WO-1 R/WO-1 U-0 U-0 U-0 U-0 R/WO-1 DEBUG XINST STVREN -- -- -- -- WDTEN bit 7 bit 0 Legend: R = Readable bit WO = Write-Once bit -n = Value when device is unprogrammed U = Unimplemented bit, read as `0' `1' = Bit is set `0' = Bit is cleared bit 7 DEBUG: Background Debugger Enable bit 1 = Background debugger disabled; RB6 and RB7 configured as general purpose I/O pins 0 = Background debugger enabled; RB6 and RB7 are dedicated to In-Circuit Debug bit 6 XINST: Extended Instruction Set Enable bit 1 = Instruction set extension and Indexed Addressing mode enabled 0 = Instruction set extension and Indexed Addressing mode disabled (Legacy mode) bit 5 STVREN: Stack Overflow/Underflow Reset Enable bit 1 = Reset on stack overflow/underflow enabled 0 = Reset on stack overflow/underflow disabled bit 4-1 Unimplemented: Read as `0' bit 0 WDTEN: Watchdog Timer Enable bit 1 = WDT enabled 0 = WDT disabled (control is placed on the SWDTEN bit) REGISTER 23-2: CONFIG1H: CONFIGURATION REGISTER 1 HIGH (BYTE ADDRESS 300001h) U-0 U-0 U-0 U-0 U-0 R/WO-1 U-0 U-0 --(1) --(1) --(1) --(1) --(2) CP0 -- -- bit 7 bit 0 Legend: R = Readable bit WO = Write-Once bit -n = Value when device is unprogrammed bit 7-3 Unimplemented: Read as `0' bit 2 CP0: Code Protection bit 1 = Program memory is not code-protected 0 = Program memory is code-protected bit 1-0 Unimplemented: Read as `0' Note 1: 2: U = Unimplemented bit, read as `0' `1' = Bit is set `0' = Bit is cleared The value of these bits in program memory should always be `1'. This ensures that the location is executed as a NOP if it is accidentally executed. This bit should always be maintained as `0'. 2010 Microchip Technology Inc. DS39770C-page 293 PIC18F85J90 FAMILY REGISTER 23-3: R/WO-1 IESO bit 7 CONFIG2L: CONFIGURATION REGISTER 2 LOW (BYTE ADDRESS 300002h) R/WO-1 U-0 U-0 U-0 R/WO-1 R/WO-1 R/WO-1 FCMEN -- -- -- FOSC2 FOSC1 FOSC0 bit 0 Legend: R = Readable bit WO = Write-Once bit -n = Value when device is unprogrammed U = Unimplemented bit, read as `0' `1' = Bit is set `0' = Bit is cleared bit 7 IESO: Two-Speed Start-up (Internal/External Oscillator Switchover) Control bit 1 = Two-Speed Start-up is enabled 0 = Two-Speed Start-up is disabled bit 6 FCMEN: Fail-Safe Clock Monitor Enable bit 1 = Fail-Safe Clock Monitor is enabled 0 = Fail-Safe Clock Monitor is disabled Unimplemented: Read as `0' bit 5-3 bit 2-0 FOSC<2:0>: Oscillator Selection bits 111 = OSC1/OSC2 as primary; EC oscillator with CLKO function and software controlled PLL (EC+PLL) 110 = OSC1/OSC2 as primary; EC oscillator with CLKO function (EC) 101 = OSC1/OSC2 as primary; HS oscillator with software controlled PLL (HS+PLL) 100 = OSC1/OSC2 as primary; HS oscillator (HS) 011 = INTOSC with CLKO as primary; port function on RA7; EC oscillator with CLKO function and software controlled PLL (EC+PLL) 010 = INTOSC with CLKO as primary; port function on RA7; EC oscillator with CLKO function 001 = INTOSC as primary with port function on RA6/RA7; HS oscillator with software controlled PLL (HS+PLL) 000 = INTOSC as primary with port function on RA6/RA7; HS oscillator (HS) DS39770C-page 294 2010 Microchip Technology Inc. PIC18F85J90 FAMILY REGISTER 23-4: CONFIG2H: CONFIGURATION REGISTER 2 HIGH (BYTE ADDRESS 300003h) U-0 U-0 U-0 U-0 (1) (1) (1) (1) -- -- -- -- R/WO-1 R/WO-1 R/WO-1 R/WO-1 WDTPS3 WDTPS2 WDTPS1 WDTPS0 bit 0 bit 7 Legend: R = Readable bit WO = Write-Once bit -n = Value when device is unprogrammed bit 7-4 bit 3-0 Note 1: U = Unimplemented bit, read as `0' `1' = Bit is set `0' = Bit is cleared Unimplemented: Read as `0' WDTPS<3:0>: Watchdog Timer Postscale Select bits 1111 = 1:32,768 1110 = 1:16,384 1101 = 1:8,192 1100 = 1:4,096 1011 = 1:2,048 1010 = 1:1,024 1001 = 1:512 1000 = 1:256 0111 = 1:128 0110 = 1:64 0101 = 1:32 0100 = 1:16 0011 = 1:8 0010 = 1:4 0001 = 1:2 0000 = 1:1 The value of these bits in program memory should always be `1'. This ensures that the location is executed as a NOP if it is accidentally executed. REGISTER 23-5: CONFIG3H: CONFIGURATION REGISTER 3 HIGH (BYTE ADDRESS 300005h) U-0 U-0 U-0 U-0 U-0 U-0 U-0 R/WO-1 --(1) --(1) --(1) --(1) -- -- -- CCP2MX bit 7 bit 0 Legend: R = Readable bit WO = Write-Once bit -n = Value when device is unprogrammed bit 7-1 Unimplemented: Read as `0' bit 0 CCP2MX: CCP2 MUX bit 1 = CCP2 is multiplexed with RC1 0 = CCP2 is multiplexed with RE7 Note 1: U = Unimplemented bit, read as `0' `1' = Bit is set `0' = Bit is cleared The value of these bits in program memory should always be `1'. This ensures that the location is executed as a NOP if it is accidentally executed. 2010 Microchip Technology Inc. DS39770C-page 295 PIC18F85J90 FAMILY REGISTER 23-6: DEVID1: DEVICE ID REGISTER 1 FOR PIC18F85J90 FAMILY DEVICES R R R R R R R R DEV2 DEV1 DEV0 REV4 REV3 REV2 REV1 REV0 bit 7 bit 0 Legend: R = Read-only bit bit 7-5 DEV<2:0>: Device ID bits 111 = PIC18F85J90 101 = PIC18F84J90 100 = PIC18F83J90 011 = PIC18F65J90 001 = PIC18F64J90 000 = PIC18F63J90 bit 4-0 REV<4:0>: Revision ID bits These bits are used to indicate the device revision. REGISTER 23-7: DEVID2: DEVICE ID REGISTER 2 FOR PIC18F85J90 FAMILY DEVICES R R R R R R R R DEV10(1) DEV9(1) DEV8(1) DEV7(1) DEV6(1) DEV5(1) DEV4(1) DEV3(1) bit 7 bit 0 Legend: R = Read-only bit bit 7-0 Note 1: DEV<10:3>: Device ID bits(1) These bits are used with the DEV<2:0> bits in the Device ID Register 1 to identify the part number. 0011 1000 = PIC18F6XJ90/8XJ90 devices The values for DEV<10:3> may be shared with other device families. The specific device is always identified by using the entire DEV<10:0> bit sequence. DS39770C-page 296 2010 Microchip Technology Inc. PIC18F85J90 FAMILY 23.2 Watchdog Timer (WDT) For PIC18F85J90 family devices, the WDT is driven by the INTRC oscillator. When the WDT is enabled, the clock source is also enabled. The nominal WDT period is 4 ms and has the same stability as the INTRC oscillator. The 4 ms period of the WDT is multiplied by a 16-bit postscaler. Any output of the WDT postscaler is selected by a multiplexor, controlled by the WDTPS bits in Configuration Register 2H. Available periods range from 4 ms to 131.072 seconds (2.18 minutes). The WDT and postscaler are cleared whenever a SLEEP or CLRWDT instruction is executed, or a clock failure (primary or Timer1 oscillator) has occurred. FIGURE 23-1: SWDTEN Note 1: The CLRWDT and SLEEP instructions clear the WDT and postscaler counts when executed. 2: When a CLRWDT instruction is executed, the postscaler count will be cleared. 23.2.1 CONTROL REGISTER The WDTCON register (Register 23-8) is a readable and writable register. The SWDTEN bit enables or disables WDT operation. This allows software to override the WDTEN Configuration bit and enable the WDT only if it has been disabled by the Configuration bit. WDT BLOCK DIAGRAM Enable WDT INTRC Control WDT Counter INTRC Oscillator Programmable Postscaler 1:1 to 1:32,768 CLRWDT All Device Resets WDTPS<3:0> Wake-up from Power-Managed Modes 128 4 Reset WDT Reset WDT Sleep 2010 Microchip Technology Inc. DS39770C-page 297 PIC18F85J90 FAMILY REGISTER 23-8: R/W-0 (1) REGSLP WDTCON: WATCHDOG TIMER CONTROL REGISTER U-0 U-0 U-0 U-0 U-0 U-0 R/W-0 -- -- -- -- -- -- SWDTEN(2) bit 7 bit 0 Legend: R = Readable bit W = Writable bit U = Unimplemented bit, read as `0' -n = Value at POR `1' = Bit is set `0' = Bit is cleared REGSLP: Voltage Regulator Low-Power Operation Enable bit(1) 1 = On-chip regulator enters low-power operation when device enters Sleep mode 0 = On-chip regulator continues to operate normally in Sleep mode bit 7 bit 6-1 Unimplemented: Read as `0' bit 0 SWDTEN: Software Controlled Watchdog Timer Enable bit(2) 1 = Watchdog Timer is on 0 = Watchdog Timer is off Note 1: 2: The REGSLP bit is automatically cleared when a Low-Voltage Detect condition occurs. This bit has no effect if the Configuration bit, WDTEN, is enabled. TABLE 23-3: Name RCON WDTCON x = Bit is unknown SUMMARY OF WATCHDOG TIMER REGISTERS Bit 0 Reset Values on page POR BOR 58 -- SWDTEN 58 Bit 7 Bit 6 Bit 5 Bit 4 Bit 3 Bit 2 Bit 1 IPEN -- CM RI TO PD REGSLP -- -- -- -- -- Legend: -- = unimplemented, read as `0'. Shaded cells are not used by the Watchdog Timer. DS39770C-page 298 2010 Microchip Technology Inc. PIC18F85J90 FAMILY 23.3 On-Chip Voltage Regulator All of the PIC18F85J90 family devices power their core digital logic at a nominal 2.5V. For designs that are required to operate at a higher typical voltage, such as 3.3V, all devices in the PIC18F85J90 family incorporate an on-chip regulator that allows the device to run its core logic from VDD. The regulator is controlled by the ENVREG pin. Tying VDD to the pin enables the regulator, which in turn, provides power to the core from the other VDD pins. When the regulator is enabled, a low-ESR filter capacitor must be connected to the VDDCORE/VCAP pin (Figure 23-2). This helps to maintain the stability of the regulator. The recommended value for the filter capacitor is provided in Section 26.3 "DC Characteristics: PIC18F84J90 Family (Industrial)". If ENVREG is tied to VSS, the regulator is disabled. In this case, separate power for the core logic at a nominal 2.5V must be supplied to the device on the VDDCORE/VCAP pin to run the I/O pins at higher voltage levels, typically 3.3V. Alternatively, the VDDCORE/VCAP and VDD pins can be tied together to operate at a lower nominal voltage. Refer to Figure 23-2 for possible configurations. 23.3.1 VOLTAGE REGULATION AND LOW-VOLTAGE DETECTION When it is enabled, the on-chip regulator provides a constant voltage of 2.5V nominal to the digital core logic. The regulator can provide this level from a VDD of about 2.5V, all the way up to the device's VDDMAX. It does not have the capability to boost VDD levels below 2.5V. In order to prevent "brown-out" conditions, when the voltage drops too low for the regulator, the regulator enters Tracking mode. In Tracking mode, the regulator output follows VDD, with a typical voltage drop of 100 mV. The on-chip regulator includes a simple Low-Voltage Detect (LVD) circuit. If VDD drops too low to maintain approximately 2.45V on VDDCORE, the circuit sets the Low-Voltage Detect Interrupt Flag, LVDIF (PIR2<2>), and clears the REGSLP (WDTCON<7>) bit if it was set. FIGURE 23-2: CONNECTIONS FOR THE ON-CHIP REGULATOR Regulator Enabled (ENVREG tied to VDD): 3.3V PIC18F85J90 VDD ENVREG VDDCORE/VCAP CF VSS Regulator Disabled (ENVREG tied to ground): 2.5V(1) 3.3V(1) PIC18F85J90 VDD ENVREG VDDCORE/VCAP VSS Regulator Disabled (VDD tied to VDDCORE): 2.5V(1) PIC18F85J90 VDD ENVREG VDDCORE/VCAP VSS Note 1: These are typical operating voltages. Refer to Section 26.1 "DC Characteristics: Supply Voltage" for the full operating ranges of VDD and VDDCORE. This can be used to generate an interrupt and put the application into a low-power operational mode, or trigger an orderly shutdown. Low-Voltage Detection is only available when the regulator is enabled. 2010 Microchip Technology Inc. DS39770C-page 299 PIC18F85J90 FAMILY 23.3.2 ON-CHIP REGULATOR AND BOR The REGSLP bit is automatically cleared by hardware when a Low-Voltage Detect condition occurs. The REGSLP bit can be set again in software, which would continue to keep the voltage regulator in Low-Power mode. This, however, is not recommended if any write operations to the Flash will be performed. When the on-chip regulator is enabled, PIC18F85J90 family devices also have a simple Brown-out Reset capability. If the voltage supplied to the regulator falls to a level that is inadequate to maintain a regulated output for full-speed operation, the regulator Reset circuitry will generate a Brown-out Reset. This event is captured by the BOR flag bit (RCON<0>). 23.4 The Two-Speed Start-up feature helps to minimize the latency period, from oscillator start-up to code execution, by allowing the microcontroller to use the INTRC oscillator as a clock source until the primary clock source is available. It is enabled by setting the IESO Configuration bit. The operation of the BOR is described in more detail in Section 5.4 "Brown-out Reset (BOR)" and Section 5.4.1 "Detecting BOR". 23.3.3 POWER-UP REQUIREMENTS The on-chip regulator is designed to meet the power-up requirements for the device. If the application does not use the regulator, then strict power-up conditions must be adhered to. While powering up, VDDCORE must never exceed VDD by 0.3 volts. 23.3.4 Two-Speed Start-up should be enabled only if the primary oscillator mode is HS or HSPLL (Crystal-Based) modes. Since the EC and ECPLL modes do not require an OST start-up delay, Two-Speed Start-up should be disabled. OPERATION IN SLEEP MODE When enabled, Resets and wake-ups from Sleep mode cause the device to configure itself to run from the internal oscillator block as the clock source, following the time-out of the Power-up Timer after a Power-on Reset is enabled. This allows almost immediate code execution while the primary oscillator starts and the OST is running. Once the OST times out, the device automatically switches to PRI_RUN mode. When enabled, the on-chip regulator always consumes a small incremental amount of current over IDD. This includes when the device is in Sleep mode, even though the core digital logic does not require power. To provide additional savings in applications where power resources are critical, the regulator can be configured to automatically disable itself whenever the device goes into Sleep mode. This feature is controlled by the REGSLP bit (WDTCON<7>). Setting this bit disables the regulator in Sleep mode, and reduces its current consumption to a minimum. In all other power-managed modes, Two-Speed Start-up is not used. The device will be clocked by the currently selected clock source until the primary clock source becomes available. The setting of the IESO bit is ignored. Substantial Sleep mode power savings can be obtained by setting the REGSLP bit, but device wake-up time will increase in order to ensure the regulator has enough time to stabilize. FIGURE 23-3: Two-Speed Start-up TIMING TRANSITION FOR TWO-SPEED START-UP (INTRC TO HSPLL) Q1 Q2 Q3 Q4 Q2 Q3 Q4 Q1 Q2 Q3 Q1 INTRC OSC1 TOST(1) TPLL(1) 1 PLL Clock Output 2 n-1 n Clock Transition CPU Clock Peripheral Clock Program Counter PC Wake from Interrupt Event Note 1: DS39770C-page 300 PC + 2 PC + 4 PC + 6 OSTS bit Set TOST = 1024 TOSC; TPLL = 2 ms (approx). These intervals are not shown to scale. 2010 Microchip Technology Inc. PIC18F85J90 FAMILY 23.4.1 SPECIAL CONSIDERATIONS FOR USING TWO-SPEED START-UP While using the INTRC oscillator in Two-Speed Start-up, the device still obeys the normal command sequences for entering power-managed modes, including serial SLEEP instructions (refer to Section 4.1.4 "Multiple Sleep Commands"). In practice, this means that user code can change the SCS<1:0> bit settings or issue SLEEP instructions before the OST times out. This would allow an application to briefly wake-up, perform routine "housekeeping" tasks and return to Sleep before the device starts to operate from the primary oscillator. User code can also check if the primary clock source is currently providing the device clocking by checking the status of the OSTS bit (OSCCON<3>). If the bit is set, the primary oscillator is providing the clock. Otherwise, the internal oscillator block is providing the clock during wake-up from Reset or Sleep mode. 23.5 Fail-Safe Clock Monitor Clock failure is tested for on the falling edge of the sample clock. If a sample clock falling edge occurs while CM is still set, a clock failure has been detected (Figure 23-5). This causes the following: * the FSCM generates an oscillator fail interrupt by setting bit, OSCFIF (PIR2<7>); * the device clock source is switched to the internal oscillator block (OSCCON is not updated to show the current clock source - this is the fail-safe condition); and * the WDT is reset. During switchover, the postscaler frequency from the internal oscillator block may not be sufficiently stable for timing-sensitive applications. In these cases, it may be desirable to select another clock configuration and enter an alternate power-managed mode. This can be done to attempt a partial recovery or execute a controlled shutdown. See Section 4.1.4 "Multiple Sleep Commands" and Section 23.4.1 "Special Considerations for Using Two-Speed Start-up" for more details. The Fail-Safe Clock Monitor (FSCM) allows the microcontroller to continue operation in the event of an external oscillator failure by automatically switching the device clock to the internal oscillator block. The FSCM function is enabled by setting the FCMEN Configuration bit. The FSCM will detect failures of the primary or secondary clock sources only. If the internal oscillator block fails, no failure would be detected, nor would any action be possible. When FSCM is enabled, the INTRC oscillator runs at all times to monitor clocks to peripherals and provides a backup clock in the event of a clock failure. Clock monitoring (shown in Figure 23-4) is accomplished by creating a sample clock signal which is the INTRC output divided by 64. This allows ample time between FSCM sample clocks for a peripheral clock edge to occur. The peripheral device clock and the sample clock are presented as inputs to the Clock Monitor latch (CM). The CM is set on the falling edge of the device clock source but cleared on the rising edge of the sample clock. Both the FSCM and the WDT are clocked by the INTRC oscillator. Since the WDT operates with a separate divider and counter, disabling the WDT has no effect on the operation of the INTRC oscillator when the FSCM is enabled. FIGURE 23-4: FSCM BLOCK DIAGRAM Clock Monitor Latch (CM) (edge-triggered) Peripheral Clock INTRC Source (32 s) / 64 S Q C Q 23.5.1 FSCM AND THE WATCHDOG TIMER As already noted, the clock source is switched to the INTRC clock when a clock failure is detected; this may mean a substantial change in the speed of code execution. If the WDT is enabled with a small prescale value, a decrease in clock speed allows a WDT time-out to occur and a subsequent device Reset. For this reason, Fail-Safe Clock Monitor events also reset the WDT and postscaler, allowing it to start timing from when execution speed was changed and decreasing the likelihood of an erroneous time-out. If the interrupt is disabled, subsequent interrupts while in Idle mode will cause the CPU to begin executing instructions while being clocked by the INTRC source. 488 Hz (2.048 ms) Clock Failure Detected 2010 Microchip Technology Inc. DS39770C-page 301 PIC18F85J90 FAMILY FIGURE 23-5: FSCM TIMING DIAGRAM Sample Clock Oscillator Failure Device Clock Output CM Output (Q) Failure Detected OSCFIF CM Test Note: 23.5.2 CM Test The device clock is normally at a much higher frequency than the sample clock. The relative frequencies in this example have been chosen for clarity. EXITING FAIL-SAFE OPERATION The fail-safe condition is terminated by either a device Reset or by entering a power-managed mode. On Reset, the controller starts the primary clock source specified in Configuration Register 2H (with any required start-up delays that are required for the oscillator mode, such as OST or PLL timer). The INTRC oscillator provides the device clock until the primary clock source becomes ready (similar to a Two-Speed Start-up). The clock source is then switched to the primary clock (indicated by the OSTS bit in the OSCCON register becoming set). The Fail-Safe Clock Monitor then resumes monitoring the peripheral clock. The primary clock source may never become ready during start-up. In this case, operation is clocked by the INTOSC multiplexor. The OSCCON register will remain in its Reset state until a power-managed mode is entered. 23.5.3 CM Test FSCM INTERRUPTS IN POWER-MANAGED MODES By entering a power-managed mode, the clock multiplexor selects the clock source selected by the OSCCON register. Fail-Safe Clock Monitoring of the power-managed clock source resumes in the power-managed mode. If an oscillator failure occurs during power-managed operation, the subsequent events depend on whether or not the oscillator failure interrupt is enabled. If enabled (OSCFIF = 1), code execution will be clocked by the INTRC multiplexor. An automatic transition back to the failed clock source will not occur. DS39770C-page 302 23.5.4 POR OR WAKE-UP FROM SLEEP The FSCM is designed to detect oscillator failure at any point after the device has exited Power-on Reset (POR) or low-power Sleep mode. When the primary device clock is either EC or INTRC mode, monitoring can begin immediately following these events. For HS or HSPLL modes, the situation is somewhat different. Since the oscillator may require a start-up time considerably longer than the FSCM sample clock time, a false clock failure may be detected. To prevent this, the internal oscillator block is automatically configured as the device clock and functions until the primary clock is stable (the OST and PLL timers have timed out). This is identical to Two-Speed Start-up mode. Once the primary clock is stable, the INTRC returns to its role as the FSCM source. Note: The same logic that prevents false oscillator failure interrupts on POR, or wake from Sleep, will also prevent the detection of the oscillator's failure to start at all following these events. This can be avoided by monitoring the OSTS bit and using a timing routine to determine if the oscillator is taking too long to start. Even so, no oscillator failure interrupt will be flagged. As noted in Section 23.4.1 "Special Considerations for Using Two-Speed Start-up", it is also possible to select another clock configuration and enter an alternate power-managed mode while waiting for the primary clock to become stable. When the new power-managed mode is selected, the primary clock is disabled. 2010 Microchip Technology Inc. PIC18F85J90 FAMILY 23.6 Program Verification and Code Protection For all devices in the PIC18F85J90 family of devices, the on-chip program memory space is treated as a single block. Code protection for this block is controlled by one Configuration bit, CP0. This bit inhibits external reads and writes to the program memory space. It has no direct effect in normal execution mode. 23.6.1 CONFIGURATION REGISTER PROTECTION The Configuration registers are protected against untoward changes or reads in two ways. The primary protection is the write-once feature of the Configuration bits which prevents reconfiguration once the bit has been programmed during a power cycle. To safeguard against unpredictable events, Configuration bit changes resulting from individual cell-level disruptions (such as ESD events) will cause a parity error and trigger a device Reset. The data for the Configuration registers is derived from the Flash Configuration Words in program memory. When the CP0 bit set, the source data for device configuration is also protected as a consequence. 2010 Microchip Technology Inc. 23.7 In-Circuit Serial Programming PIC18F85J90 family microcontrollers can be serially programmed while in the end application circuit. This is simply done with two lines for clock and data and three other lines for power, ground and the programming voltage. This allows customers to manufacture boards with unprogrammed devices and then program the microcontroller just before shipping the product. This also allows the most recent firmware or a custom firmware to be programmed. 23.8 In-Circuit Debugger When the DEBUG Configuration bit is programmed to a `0', the In-Circuit Debugger functionality is enabled. This function allows simple debugging functions when used with MPLAB(R) IDE. When the microcontroller has this feature enabled, some resources are not available for general use. Table 23-4 shows which resources are required by the background debugger. TABLE 23-4: DEBUGGER RESOURCES I/O pins: RB6, RB7 Stack: 2 levels Program Memory: 512 bytes Data Memory: 10 bytes DS39770C-page 303 PIC18F85J90 FAMILY NOTES: DS39770C-page 304 2010 Microchip Technology Inc. PIC18F85J90 FAMILY 24.0 INSTRUCTION SET SUMMARY The PIC18F85J90 family of devices incorporate the standard set of 75 PIC18 core instructions, as well as an extended set of 8 new instructions for the optimization of code that is recursive or that utilizes a software stack. The extended set is discussed later in this section. 24.1 Standard Instruction Set The standard PIC18 instruction set adds many enhancements to the previous PIC(R) MCU instruction sets, while maintaining an easy migration from these PIC MCU instruction sets. Most instructions are a single program memory word (16 bits), but there are four instructions that require two program memory locations. Each single-word instruction is a 16-bit word divided into an opcode, which specifies the instruction type and one or more operands, which further specify the operation of the instruction. The instruction set is highly orthogonal and is grouped into four basic categories: * * * * Byte-oriented operations Bit-oriented operations Literal operations Control operations The PIC18 instruction set summary in Table 24-2 lists byte-oriented, bit-oriented, literal and control operations. Table 24-1 shows the opcode field descriptions. Most byte-oriented instructions have three operands: 1. 2. 3. The file register (specified by `f') The destination of the result (specified by `d') The accessed memory (specified by `a') The file register designator, `f', specifies which file register is to be used by the instruction. The destination designator, `d', specifies where the result of the operation is to be placed. If `d' is zero, the result is placed in the WREG register. If `d' is one, the result is placed in the file register specified in the instruction. All bit-oriented instructions have three operands: 1. 2. 3. The file register (specified by `f') The bit in the file register (specified by `b') The accessed memory (specified by `a') The literal instructions may use some of the following operands: * A literal value to be loaded into a file register (specified by `k') * The desired FSR register to load the literal value into (specified by `f') * No operand required (specified by `--') The control instructions may use some of the following operands: * A program memory address (specified by `n') * The mode of the CALL or RETURN instructions (specified by `s') * The mode of the table read and table write instructions (specified by `m') * No operand required (specified by `--') All instructions are a single word, except for four double-word instructions. These instructions were made double-word to contain the required information in 32 bits. In the second word, the 4 MSbs are `1's. If this second word is executed as an instruction (by itself), it will execute as a NOP. All single-word instructions are executed in a single instruction cycle, unless a conditional test is true or the program counter is changed as a result of the instruction. In these cases, the execution takes two instruction cycles with the additional instruction cycle(s) executed as a NOP. The double-word instructions execute in two instruction cycles. One instruction cycle consists of four oscillator periods. Thus, for an oscillator frequency of 4 MHz, the normal instruction execution time is 1 s. If a conditional test is true, or the program counter is changed as a result of an instruction, the instruction execution time is 2 s. Two-word branch instructions (if true) would take 3 s. Figure 24-1 shows the general formats that the instructions can have. All examples use the convention `nnh' to represent a hexadecimal number. The Instruction Set Summary, shown in Table 24-2, lists the standard instructions recognized by the Microchip MPASMTM Assembler. Section 24.1.1 "Standard Instruction Set" provides a description of each instruction. The bit field designator, `b', selects the number of the bit affected by the operation, while the file register designator, `f', represents the number of the file in which the bit is located. 2010 Microchip Technology Inc. DS39770C-page 305 PIC18F85J90 FAMILY TABLE 24-1: OPCODE FIELD DESCRIPTIONS Field Description a RAM access bit: a = 0: RAM location in Access RAM (BSR register is ignored) a = 1: RAM bank is specified by BSR register bbb Bit address within an 8-bit file register (0 to 7). BSR Bank Select Register. Used to select the current RAM bank. C, DC, Z, OV, N ALU Status bits: Carry, Digit Carry, Zero, Overflow, Negative. d Destination select bit: d = 0: store result in WREG d = 1: store result in file register f dest Destination: either the WREG register or the specified register file location. f 8-bit Register file address (00h to FFh), or 2-bit FSR designator (0h to 3h). fs 12-bit Register file address (000h to FFFh). This is the source address. fd 12-bit Register file address (000h to FFFh). This is the destination address. GIE Global Interrupt Enable bit. k Literal field, constant data or label (may be either an 8-bit, 12-bit or a 20-bit value). label Label name. mm The mode of the TBLPTR register for the table read and table write instructions. Only used with table read and table write instructions: * No Change to register (such as TBLPTR with table reads and writes) *+ Post-Increment register (such as TBLPTR with table reads and writes) *- Post-Decrement register (such as TBLPTR with table reads and writes) Pre-Increment register (such as TBLPTR with table reads and writes) +* n The relative address (2's complement number) for relative branch instructions or the direct address for Call/Branch and Return instructions. PC Program Counter. PCL Program Counter Low Byte. PCH Program Counter High Byte. PCLATH Program Counter High Byte Latch. PCLATU Program Counter Upper Byte Latch. PD Power-Down bit. PRODH Product of Multiply High Byte. PRODL Product of Multiply Low Byte. s Fast Call/Return mode select bit: s = 0: do not update into/from shadow registers s = 1: certain registers loaded into/from shadow registers (Fast mode) TBLPTR 21-bit Table Pointer (points to a Program Memory location). TABLAT 8-bit Table Latch. TO Time-out bit. TOS Top-of-Stack. u Unused or Unchanged. WDT Watchdog Timer. WREG Working register (accumulator). x Don't care (`0' or `1'). The assembler will generate code with x = 0. It is the recommended form of use for compatibility with all Microchip software tools. zs 7-bit offset value for Indirect Addressing of register files (source). 7-bit offset value for Indirect Addressing of register files (destination). zd { } Optional argument. [text] Indicates an Indexed Address. (text) The contents of text. [expr]<n> Specifies bit n of the register indicated by the pointer expr. Assigned to. < > Register bit field. In the set of. italics User-defined term (font is Courier). DS39770C-page 306 2010 Microchip Technology Inc. PIC18F85J90 FAMILY FIGURE 24-1: GENERAL FORMAT FOR INSTRUCTIONS Byte-oriented file register operations 15 10 9 OPCODE Example Instruction 8 7 d 0 a f (FILE #) ADDWF MYREG, W, B d = 0 for result destination to be WREG register d = 1 for result destination to be file register (f) a = 0 to force Access Bank a = 1 for BSR to select bank f = 8-bit file register address Byte to Byte move operations (2-word) 15 12 11 0 OPCODE 15 f (Source FILE #) 12 11 MOVFF MYREG1, MYREG2 0 f (Destination FILE #) 1111 f = 12-bit file register address Bit-oriented file register operations 15 12 11 9 8 7 0 OPCODE b (BIT #) a f (FILE #) BSF MYREG, bit, B b = 3-bit position of bit in file register (f) a = 0 to force Access Bank a = 1 for BSR to select bank f = 8-bit file register address Literal operations 15 8 7 0 OPCODE k (literal) MOVLW 7Fh k = 8-bit immediate value Control operations CALL, GOTO and Branch operations 15 8 7 0 OPCODE 15 n<7:0> (literal) 12 11 GOTO Label 0 n<19:8> (literal) 1111 n = 20-bit immediate value 15 8 7 OPCODE 15 S 0 n<7:0> (literal) 12 11 CALL MYFUNC 0 n<19:8> (literal) 1111 S = Fast bit 15 11 10 OPCODE 15 0 n<10:0> (literal) 8 7 OPCODE 2010 Microchip Technology Inc. BRA MYFUNC 0 n<7:0> (literal) BC MYFUNC DS39770C-page 307 PIC18F85J90 FAMILY TABLE 24-2: PIC18F85J90 FAMILY INSTRUCTION SET Mnemonic, Operands Description Cycles 16-Bit Instruction Word MSb LSb Status Affected Notes BYTE-ORIENTED OPERATIONS ADDWF ADDWFC ANDWF CLRF COMF CPFSEQ CPFSGT CPFSLT DECF DECFSZ DCFSNZ INCF INCFSZ INFSNZ IORWF MOVF MOVFF f, d, a f, d, a f, d, a f, a f, d, a f, a f, a f, a f, d, a f, d, a f, d, a f, d, a f, d, a f, d, a f, d, a f, d, a f s, f d MOVWF MULWF NEGF RLCF RLNCF RRCF RRNCF SETF SUBFWB f, a f, a f, a f, d, a f, d, a f, d, a f, d, a f, a f, d, a SUBWF SUBWFB f, d, a f, d, a SWAPF TSTFSZ XORWF f, d, a f, a f, d, a Note 1: 2: 3: 4: Add WREG and f Add WREG and Carry bit to f AND WREG with f Clear f Complement f Compare f with WREG, Skip = Compare f with WREG, Skip > Compare f with WREG, Skip < Decrement f Decrement f, Skip if 0 Decrement f, Skip if Not 0 Increment f Increment f, Skip if 0 Increment f, Skip if Not 0 Inclusive OR WREG with f Move f Move fs (source) to 1st word fd (destination) 2nd word Move WREG to f Multiply WREG with f Negate f Rotate Left f through Carry Rotate Left f (No Carry) Rotate Right f through Carry Rotate Right f (No Carry) Set f Subtract f from WREG with Borrow Subtract WREG from f Subtract WREG from f with Borrow Swap Nibbles in f Test f, Skip if 0 Exclusive OR WREG with f 1 1 1 1 1 1 (2 or 3) 1 (2 or 3) 1 (2 or 3) 1 1 (2 or 3) 1 (2 or 3) 1 1 (2 or 3) 1 (2 or 3) 1 1 2 C, DC, Z, OV, N C, DC, Z, OV, N Z, N Z Z, N None None None C, DC, Z, OV, N None None C, DC, Z, OV, N None None Z, N Z, N None 1, 2 1, 2 1,2 2 1, 2 4 4 1, 2 1, 2, 3, 4 1, 2, 3, 4 1, 2 1, 2, 3, 4 4 1, 2 1, 2 1 1 1 1 1 1 1 1 1 1 0010 0010 0001 0110 0001 0110 0110 0110 0000 0010 0100 0010 0011 0100 0001 0101 1100 1111 0110 0000 0110 0011 0100 0011 0100 0110 0101 01da 00da 01da 101a 11da 001a 010a 000a 01da 11da 11da 10da 11da 10da 00da 00da ffff ffff 111a 001a 110a 01da 01da 00da 00da 100a 01da ffff ffff ffff ffff ffff ffff ffff ffff ffff ffff ffff ffff ffff ffff ffff ffff ffff ffff ffff ffff ffff ffff ffff ffff ffff ffff ffff ffff ffff ffff ffff ffff ffff ffff ffff ffff ffff ffff ffff ffff ffff ffff ffff ffff ffff ffff ffff ffff ffff ffff ffff ffff ffff ffff 1 1 0101 11da 0101 10da ffff ffff ffff C, DC, Z, OV, N ffff C, DC, Z, OV, N 1, 2 0011 10da 1 1 (2 or 3) 0110 011a 0001 10da 1 ffff ffff ffff ffff None ffff None ffff Z, N 4 1, 2 None None C, DC, Z, OV, N C, Z, N Z, N C, Z, N Z, N None C, DC, Z, OV, N 1, 2 1, 2 1, 2 When a PORT register is modified as a function of itself (e.g., MOVF PORTB, 1, 0), the value used will be that value present on the pins themselves. For example, if the data latch is `1' for a pin configured as input and is driven low by an external device, the data will be written back with a `0'. If this instruction is executed on the TMR0 register (and where applicable, d = 1), the prescaler will be cleared if assigned. If the Program Counter (PC) is modified or a conditional test is true, the instruction requires two cycles. The second cycle is executed as a NOP. Some instructions are two-word instructions. The second word of these instructions will be executed as a NOP unless the first word of the instruction retrieves the information embedded in these 16-bits. This ensures that all program memory locations have a valid instruction. DS39770C-page 308 2010 Microchip Technology Inc. PIC18F85J90 FAMILY TABLE 24-2: PIC18F85J90 FAMILY INSTRUCTION SET (CONTINUED) Mnemonic, Operands Description Cycles 16-Bit Instruction Word MSb LSb Status Affected Notes BIT-ORIENTED OPERATIONS BCF BSF BTFSC BTFSS BTG f, b, a f, b, a f, b, a f, b, a f, b, a Bit Clear f Bit Set f Bit Test f, Skip if Clear Bit Test f, Skip if Set Bit Toggle f 1 1 1 (2 or 3) 1 (2 or 3) 1 1001 1000 1011 1010 0111 bbba bbba bbba bbba bbba ffff ffff ffff ffff ffff ffff ffff ffff ffff ffff None None None None None 1 (2) 1 (2) 1 (2) 1 (2) 1 (2) 1 (2) 1 (2) 2 1 (2) 2 0010 0110 0011 0111 0101 0001 0100 0nnn 0000 110s kkkk 0000 0000 1111 kkkk 0000 xxxx 0000 0000 1nnn 0000 0000 nnnn nnnn nnnn nnnn nnnn nnnn nnnn nnnn nnnn kkkk kkkk 0000 0000 kkkk kkkk 0000 xxxx 0000 0000 nnnn 1111 0001 nnnn nnnn nnnn nnnn nnnn nnnn nnnn nnnn nnnn kkkk kkkk 0100 0111 kkkk kkkk 0000 xxxx 0110 0101 nnnn 1111 000s None None None None None None None None None None 1 1 1 1 2 1 2 1110 1110 1110 1110 1110 1110 1110 1101 1110 1110 1111 0000 0000 1110 1111 0000 1111 0000 0000 1101 0000 0000 2 2 1 0000 1100 0000 0000 0000 0000 kkkk 0001 0000 1, 2 1, 2 3, 4 3, 4 1, 2 CONTROL OPERATIONS BC BN BNC BNN BNOV BNZ BOV BRA BZ CALL n n n n n n n n n n, s CLRWDT DAW GOTO -- -- n NOP NOP POP PUSH RCALL RESET RETFIE -- -- -- -- n s Branch if Carry Branch if Negative Branch if Not Carry Branch if Not Negative Branch if Not Overflow Branch if Not Zero Branch if Overflow Branch Unconditionally Branch if Zero Call Subroutine 1st word 2nd word Clear Watchdog Timer Decimal Adjust WREG Go to Address 1st word 2nd word No Operation No Operation Pop Top of Return Stack (TOS) Push Top of Return Stack (TOS) Relative Call Software Device Reset Return from Interrupt Enable RETLW RETURN SLEEP k s -- Return with Literal in WREG Return from Subroutine Go into Standby mode Note 1: 2: 3: 4: 1 1 2 TO, PD C None None None None None None All GIE/GIEH, PEIE/GIEL kkkk None 001s None 0011 TO, PD 4 When a PORT register is modified as a function of itself (e.g., MOVF PORTB, 1, 0), the value used will be that value present on the pins themselves. For example, if the data latch is `1' for a pin configured as input and is driven low by an external device, the data will be written back with a `0'. If this instruction is executed on the TMR0 register (and where applicable, d = 1), the prescaler will be cleared if assigned. If the Program Counter (PC) is modified or a conditional test is true, the instruction requires two cycles. The second cycle is executed as a NOP. Some instructions are two-word instructions. The second word of these instructions will be executed as a NOP unless the first word of the instruction retrieves the information embedded in these 16-bits. This ensures that all program memory locations have a valid instruction. 2010 Microchip Technology Inc. DS39770C-page 309 PIC18F85J90 FAMILY TABLE 24-2: PIC18F85J90 FAMILY INSTRUCTION SET (CONTINUED) Mnemonic, Operands Description Cycles 16-Bit Instruction Word MSb LSb Status Affected Notes LITERAL OPERATIONS ADDLW ANDLW IORLW LFSR k k k f, k MOVLB MOVLW MULLW RETLW SUBLW XORLW k k k k k k Add Literal and WREG AND Literal with WREG Inclusive OR Literal with WREG Move Literal (12-bit) 2nd word to FSR(f) 1st word Move Literal to BSR<3:0> Move Literal to WREG Multiply Literal with WREG Return with Literal in WREG Subtract WREG from Literal Exclusive OR Literal with WREG 1 1 1 2 1 1 1 2 1 1 0000 0000 0000 1110 1111 0000 0000 0000 0000 0000 0000 1111 1011 1001 1110 0000 0001 1110 1101 1100 1000 1010 kkkk kkkk kkkk 00ff kkkk 0000 kkkk kkkk kkkk kkkk kkkk kkkk kkkk kkkk kkkk kkkk kkkk kkkk kkkk kkkk kkkk kkkk C, DC, Z, OV, N Z, N Z, N None 0000 0000 0000 0000 0000 0000 0000 0000 0000 0000 0000 0000 0000 0000 0000 0000 0000 0000 0000 0000 0000 0000 0000 0000 1000 1001 1010 1011 1100 1101 1110 1111 None None None None None None None None None None None None C, DC, Z, OV, N Z, N DATA MEMORY PROGRAM MEMORY OPERATIONS TBLRD* TBLRD*+ TBLRD*TBLRD+* TBLWT* TBLWT*+ TBLWT*TBLWT+* Note 1: 2: 3: 4: Table Read 2 Table Read with Post-Increment Table Read with Post-Decrement Table Read with Pre-Increment Table Write 2 Table Write with Post-Increment Table Write with Post-Increment Table Write with Pre-Increment When a PORT register is modified as a function of itself (e.g., MOVF PORTB, 1, 0), the value used will be that value present on the pins themselves. For example, if the data latch is `1' for a pin configured as input and is driven low by an external device, the data will be written back with a `0'. If this instruction is executed on the TMR0 register (and where applicable, d = 1), the prescaler will be cleared if assigned. If the Program Counter (PC) is modified or a conditional test is true, the instruction requires two cycles. The second cycle is executed as a NOP. Some instructions are two-word instructions. The second word of these instructions will be executed as a NOP unless the first word of the instruction retrieves the information embedded in these 16-bits. This ensures that all program memory locations have a valid instruction. DS39770C-page 310 2010 Microchip Technology Inc. PIC18F85J90 FAMILY 24.1.1 STANDARD INSTRUCTION SET ADDLW ADD Literal to W ADDWF ADD W to f Syntax: ADDLW Syntax: ADDWF Operands: 0 f 255 d [0,1] a [0,1] Operation: (W) + (f) dest Status Affected: N, OV, C, DC, Z k Operands: 0 k 255 Operation: (W) + k W Status Affected: N, OV, C, DC, Z Encoding: 0000 1111 kkkk kkkk Description: The contents of W are added to the 8-bit literal `k' and the result is placed in W. Words: 1 Cycles: 1 Encoding: 0010 Description: Q1 Q2 Q3 Q4 Read literal `k' Process Data Write to W Example: ADDLW ffff ffff Add W to register `f'. If `d' is `0', the result is stored in W. If `d' is `1', the result is stored back in register `f'. If `a' is `0' and the extended instruction set is enabled, this instruction operates in Indexed Literal Offset Addressing mode whenever f 95 (5Fh). See Section 24.2.3 "Byte-Oriented and Bit-Oriented Instructions in Indexed Literal Offset Mode" for details. 15h Before Instruction W = 10h After Instruction W = 25h 01da If `a' is `0', the Access Bank is selected. If `a' is `1', the BSR is used to select the GPR bank. Q Cycle Activity: Decode f {,d {,a}} Words: 1 Cycles: 1 Q Cycle Activity: Q1 Q2 Q3 Q4 Decode Read register `f' Process Data Write to destination Example: ADDWF Before Instruction W = REG = After Instruction W = REG = Note: REG, 0, 0 17h 0C2h 0D9h 0C2h All PIC18 instructions may take an optional label argument preceding the instruction mnemonic for use in symbolic addressing. If a label is used, the instruction format then becomes: {label} instruction argument(s). 2010 Microchip Technology Inc. DS39770C-page 311 PIC18F85J90 FAMILY ADDWFC ADD W and Carry bit to f ANDLW AND Literal with W Syntax: ADDWFC Syntax: ANDLW Operands: 0 f 255 d [0,1] a [0,1] f {,d {,a}} Operation: (W) + (f) + (C) dest Status Affected: N,OV, C, DC, Z Encoding: 0010 Description: 00da ffff Add W, the Carry flag and data memory location `f'. If `d' is `0', the result is placed in W. If `d' is `1', the result is placed in data memory location `f'. If `a' is `0', the Access Bank is selected. If `a' is `1', the BSR is used to select the GPR bank. If `a' is `0' and the extended instruction set is enabled, this instruction operates in Indexed Literal Offset Addressing mode whenever f 95 (5Fh). See Section 24.2.3 "Byte-Oriented and Bit-Oriented Instructions in Indexed Literal Offset Mode" for details. Words: 1 Cycles: 1 Operands: 0 k 255 Operation: (W) .AND. k W Status Affected: N, Z Encoding: ffff k 0000 1011 kkkk kkkk Description: The contents of W are ANDed with the 8-bit literal `k'. The result is placed in W. Words: 1 Cycles: 1 Q Cycle Activity: Q1 Q2 Q3 Q4 Decode Read literal `k' Process Data Write to W Example: ANDLW Before Instruction W = After Instruction W = 05Fh A3h 03h Q Cycle Activity: Q1 Q2 Q3 Q4 Decode Read register `f' Process Data Write to destination Example: ADDWFC Before Instruction Carry bit = REG = W = After Instruction Carry bit = REG = W = DS39770C-page 312 REG, 0, 1 1 02h 4Dh 0 02h 50h 2010 Microchip Technology Inc. PIC18F85J90 FAMILY ANDWF AND W with f BC Branch if Carry Syntax: ANDWF Syntax: BC Operands: 0 f 255 d [0,1] a [0,1] f {,d {,a}} Operation: (W) .AND. (f) dest Status Affected: N, Z Encoding: 0001 Description: Operands: -128 n 127 Operation: if Carry bit is `1', (PC) + 2 + 2n PC Status Affected: None Encoding: 01da ffff ffff 1110 Description: The contents of W are ANDed with register `f'. If `d' is `0', the result is stored in W. If `d' is `1', the result is stored back in register `f'. Words: 1 Cycles: 1 Q Cycle Activity: Q1 Q2 Q3 Q4 Decode Read register `f' Process Data Write to destination Example: ANDWF Before Instruction W = REG = After Instruction W = REG = REG, 0, 0 17h C2h 02h C2h 2010 Microchip Technology Inc. 0010 nnnn nnnn If the Carry bit is '1', then the program will branch. The 2's complement number `2n' is added to the PC. Since the PC will have incremented to fetch the next instruction, the new address will be PC + 2 + 2n. This instruction is then a two-cycle instruction. If `a' is `0', the Access Bank is selected. If `a' is `1', the BSR is used to select the GPR bank. If `a' is `0' and the extended instruction set is enabled, this instruction operates in Indexed Literal Offset Addressing mode whenever f 95 (5Fh). See Section 24.2.3 "Byte-Oriented and Bit-Oriented Instructions in Indexed Literal Offset Mode" for details. n Words: 1 Cycles: 1(2) Q Cycle Activity: If Jump: Q1 Q2 Q3 Q4 Decode Read literal `n' Process Data Write to PC No operation No operation No operation No operation If No Jump: Q1 Q2 Q3 Q4 Decode Read literal `n' Process Data No operation Example: HERE Before Instruction PC After Instruction If Carry PC If Carry PC BC 5 = address (HERE) = = = = 1; address (HERE + 12) 0; address (HERE + 2) DS39770C-page 313 PIC18F85J90 FAMILY BCF Bit Clear f BN Branch if Negative Syntax: BCF Syntax: BN Operands: 0 f 255 0b7 a [0,1] f, b {,a} Operation: 0 f<b> Status Affected: None Encoding: 1001 Description: Operands: -128 n 127 Operation: if Negative bit is `1', (PC) + 2 + 2n PC Status Affected: None Encoding: bbba ffff ffff 1110 Description: Bit `b' in register `f' is cleared. If `a' is `0', the Access Bank is selected. If `a' is `1', the BSR is used to select the GPR bank. If `a' is `0' and the extended instruction set is enabled, this instruction operates in Indexed Literal Offset Addressing mode whenever f 95 (5Fh). See Section 24.2.3 "Byte-Oriented and Bit-Oriented Instructions in Indexed Literal Offset Mode" for details. Words: 1 Cycles: 1 Q1 Q2 Q3 Q4 Read register `f' Process Data Write register `f' Example: BCF Before Instruction FLAG_REG = C7h After Instruction FLAG_REG = 47h DS39770C-page 314 FLAG_REG, 7, 0 0110 nnnn nnnn If the Negative bit is `1', then the program will branch. The 2's complement number, `2n', is added to the PC. Since the PC will have incremented to fetch the next instruction, the new address will be PC + 2 + 2n. This instruction is then a two-cycle instruction. Words: 1 Cycles: 1(2) Q Cycle Activity: If Jump: Q1 Q2 Q3 Q4 Decode Read literal `n' Process Data Write to PC No operation No operation No operation No operation Q Cycle Activity: Decode n If No Jump: Q1 Q2 Q3 Q4 Decode Read literal `n' Process Data No operation Example: HERE Before Instruction PC After Instruction If Negative PC If Negative PC BN Jump = address (HERE) = = = = 1; address (Jump) 0; address (HERE + 2) 2010 Microchip Technology Inc. PIC18F85J90 FAMILY BNC Branch if Not Carry BNN Branch if Not Negative Syntax: BNC Syntax: BNN n n Operands: -128 n 127 Operands: -128 n 127 Operation: if Carry bit is `0', (PC) + 2 + 2n PC Operation: if Negative bit is `0', (PC) + 2 + 2n PC Status Affected: None Status Affected: None Encoding: 1110 Description: 0011 nnnn nnnn If the Carry bit is `0', then the program will branch. Encoding: 1110 Description: The 2's complement number, `2n', is added to the PC. Since the PC will have incremented to fetch the next instruction, the new address will be PC + 2 + 2n. This instruction is then a two-cycle instruction. nnnn nnnn The 2's complement number, `2n', is added to the PC. Since the PC will have incremented to fetch the next instruction, the new address will be PC + 2 + 2n. This instruction is then a two-cycle instruction. Words: 1 Words: 1 Cycles: 1(2) Cycles: 1(2) Q Cycle Activity: If Jump: 0111 If the Negative bit is `0', then the program will branch. Q Cycle Activity: If Jump: Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Decode Read literal `n' Process Data Write to PC Decode Read literal `n' Process Data Write to PC No operation No operation No operation No operation No operation No operation No operation No operation Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Decode Read literal `n' Process Data No operation Decode Read literal `n' Process Data No operation If No Jump: Example: If No Jump: HERE Before Instruction PC After Instruction If Carry PC If Carry PC BNC Jump = address (HERE) = = = = 0; address (Jump) 1; address (HERE + 2) 2010 Microchip Technology Inc. Example: HERE Before Instruction PC After Instruction If Negative PC If Negative PC BNN Jump = address (HERE) = = = = 0; address (Jump) 1; address (HERE + 2) DS39770C-page 315 PIC18F85J90 FAMILY BNOV Branch if Not Overflow BNZ Branch if Not Zero Syntax: BNOV Syntax: BNZ n n Operands: -128 n 127 Operands: -128 n 127 Operation: if Overflow bit is `0', (PC) + 2 + 2n PC Operation: if Zero bit is `0', (PC) + 2 + 2n PC Status Affected: None Status Affected: None Encoding: 1110 Description: 0101 nnnn nnnn If the Overflow bit is `0', then the program will branch. Encoding: 1110 Description: The 2's complement number, `2n', is added to the PC. Since the PC will have incremented to fetch the next instruction, the new address will be PC + 2 + 2n. This instruction is then a two-cycle instruction. nnnn nnnn The 2's complement number, `2n', is added to the PC. Since the PC will have incremented to fetch the next instruction, the new address will be PC + 2 + 2n. This instruction is then a two-cycle instruction. Words: 1 Words: 1 Cycles: 1(2) Cycles: 1(2) Q Cycle Activity: If Jump: 0001 If the Zero bit is `0', then the program will branch. Q Cycle Activity: If Jump: Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Decode Read literal `n' Process Data Write to PC Decode Read literal `n' Process Data Write to PC No operation No operation No operation No operation No operation No operation No operation No operation Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Decode Read literal `n' Process Data No operation Decode Read literal `n' Process Data No operation If No Jump: If No Jump: Example: HERE Before Instruction PC After Instruction If Overflow PC If Overflow PC DS39770C-page 316 BNOV Jump = address (HERE) = = = = 0; address (Jump) 1; address (HERE + 2) Example: HERE Before Instruction PC After Instruction If Zero PC If Zero PC BNZ Jump = address (HERE) = = = = 0; address (Jump) 1; address (HERE + 2) 2010 Microchip Technology Inc. PIC18F85J90 FAMILY BRA Unconditional Branch BSF Bit Set f Syntax: BRA Syntax: BSF Operands: -1024 n 1023 Operands: Operation: (PC) + 2 + 2n PC Status Affected: None 0 f 255 0b7 a [0,1] Operation: 1 f<b> Status Affected: None Encoding: n 1101 Description: 0nnn nnnn nnnn Add the 2's complement number, `2n', to the PC. Since the PC will have incremented to fetch the next instruction, the new address will be PC + 2 + 2n. This instruction is a two-cycle instruction. Words: 1 Cycles: 2 Encoding: 1000 Description: Q1 Q2 Q3 Q4 Read literal `n' Process Data Write to PC No operation No operation No operation No operation Example: bbba ffff ffff Bit `b' in register `f' is set. If `a' is `0', the Access Bank is selected. If `a' is `1', the BSR is used to select the GPR bank. If `a' is `0' and the extended instruction set is enabled, this instruction operates in Indexed Literal Offset Addressing mode whenever f 95 (5Fh). See Section 24.2.3 "Byte-Oriented and Bit-Oriented Instructions in Indexed Literal Offset Mode" for details. Q Cycle Activity: Decode f, b {,a} Words: 1 Cycles: 1 Q Cycle Activity: HERE Before Instruction PC After Instruction PC BRA Jump = address (HERE) = address (Jump) Q1 Q2 Q3 Q4 Decode Read register `f' Process Data Write register `f' Example: BSF Before Instruction FLAG_REG After Instruction FLAG_REG 2010 Microchip Technology Inc. FLAG_REG, 7, 1 = 0Ah = 8Ah DS39770C-page 317 PIC18F85J90 FAMILY BTFSC Bit Test File, Skip if Clear BTFSS Bit Test File, Skip if Set Syntax: BTFSC f, b {,a} Syntax: BTFSS f, b {,a} Operands: 0 f 255 0b7 a [0,1] Operands: 0 f 255 0b<7 a [0,1] Operation: skip if (f<b>) = 0 Operation: skip if (f<b>) = 1 Status Affected: None Status Affected: None Encoding: 1011 Description: bbba ffff ffff If bit `b' in register `f' is `0', then the next instruction is skipped. If bit `b' is `0', then the next instruction fetched during the current instruction execution is discarded and a NOP is executed instead, making this a two-cycle instruction. Encoding: 1010 Description: bbba ffff ffff If bit `b' in register `f' is `1', then the next instruction is skipped. If bit `b' is `1', then the next instruction fetched during the current instruction execution is discarded and a NOP is executed instead, making this a two-cycle instruction. If `a' is `0', the Access Bank is selected. If `a' is `1', the BSR is used to select the GPR bank. If `a' is `0', the Access Bank is selected. If `a' is `1', the BSR is used to select the GPR bank. If `a' is `0' and the extended instruction set is enabled, this instruction operates in Indexed Literal Offset Addressing mode whenever f 95 (5Fh). See Section 24.2.3 "Byte-Oriented and Bit-Oriented Instructions in Indexed Literal Offset Mode" for details. If `a' is `0' and the extended instruction set is enabled, this instruction operates in Indexed Literal Offset Addressing mode whenever f 95 (5Fh). See Section 24.2.3 "Byte-Oriented and Bit-Oriented Instructions in Indexed Literal Offset Mode" for details. Words: 1 Words: 1 Cycles: 1(2) Note: Cycles: 1(2) Note: 3 cycles if skip and followed by a 2-word instruction. Q Cycle Activity: 3 cycles if skip and followed by a 2-word instruction. Q Cycle Activity: Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Decode Read register `f' Process Data No operation Decode Read register `f' Process Data No operation Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 No operation No operation No operation No operation No operation No operation No operation No operation If skip: If skip: If skip and followed by 2-word instruction: If skip and followed by 2-word instruction: Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 No operation No operation No operation No operation No operation No operation No operation No operation No operation No operation No operation No operation No operation No operation No operation No operation Example: HERE FALSE TRUE Before Instruction PC After Instruction If FLAG<1> PC If FLAG<1> PC DS39770C-page 318 BTFSC : : FLAG, 1, 0 = address (HERE) = = = = 0; address (TRUE) 1; address (FALSE) Example: HERE FALSE TRUE Before Instruction PC After Instruction If FLAG<1> PC If FLAG<1> PC BTFSS : : FLAG, 1, 0 = address (HERE) = = = = 0; address (FALSE) 1; address (TRUE) 2010 Microchip Technology Inc. PIC18F85J90 FAMILY BTG Bit Toggle f BOV Branch if Overflow Syntax: BTG f, b {,a} Syntax: BOV Operands: 0 f 255 0b<7 a [0,1] Operands: -128 n 127 Operation: if Overflow bit is `1', (PC) + 2 + 2n PC Status Affected: None Operation: (f<b>) f<b> Status Affected: None Encoding: 0111 Description: Encoding: bbba ffff ffff 1110 Description: Bit `b' in data memory location `f' is inverted. Words: 1 Cycles: 1 Q Cycle Activity: Q1 Q2 Q3 Q4 Decode Read register `f' Process Data Write register `f' Example: BTG PORTC, 2010 Microchip Technology Inc. Words: 1 Cycles: nnnn nnnn 1(2) Q Cycle Activity: If Jump: Q1 Q2 Q3 Q4 Decode Read literal `n' Process Data Write to PC No operation No operation No operation No operation If No Jump: Q1 Q2 Q3 Q4 Decode Read literal `n' Process Data No operation 4, 0 Before Instruction: PORTC = 0111 0101 [75h] After Instruction: PORTC = 0110 0101 [65h] 0100 If the Overflow bit is `1', then the program will branch. The 2's complement number `2n' is added to the PC. Since the PC will have incremented to fetch the next instruction, the new address will be PC + 2 + 2n. This instruction is then a two-cycle instruction. If `a' is `0', the Access Bank is selected. If `a' is `1', the BSR is used to select the GPR bank. If `a' is `0' and the extended instruction set is enabled, this instruction operates in Indexed Literal Offset Addressing mode whenever f 95 (5Fh). See Section 24.2.3 "Byte-Oriented and Bit-Oriented Instructions in Indexed Literal Offset Mode" for details. n Example: HERE Before Instruction PC After Instruction If Overflow PC If Overflow PC BOV Jump = address (HERE) = = = = 1; address (Jump) 0; address (HERE + 2) DS39770C-page 319 PIC18F85J90 FAMILY BZ Branch if Zero CALL Subroutine Call Syntax: BZ Syntax: CALL k {,s} n Operands: -128 n 127 Operands: Operation: if Zero bit is `1', (PC) + 2 + 2n PC 0 k 1048575 s [0,1] Operation: Status Affected: None (PC) + 4 TOS, k PC<20:1>; if s = 1 (W) WS, (STATUS) STATUSS, (BSR) BSRS Status Affected: None Encoding: 1110 Description: 0000 nnnn nnnn If the Zero bit is `1', then the program will branch. The 2's complement number `2n' is added to the PC. Since the PC will have incremented to fetch the next instruction, the new address will be PC + 2 + 2n. This instruction is then a two-cycle instruction. Words: 1 Cycles: 1(2) Encoding: 1st word (k<7:0>) 2nd word(k<19:8>) Q1 Q2 Q3 Q4 Read literal `n' Process Data Write to PC No operation No operation No operation No operation Q1 Q2 Q3 Q4 Decode Read literal `n' Process Data No operation If No Jump: Example: HERE Before Instruction PC After Instruction If Zero PC If Zero PC DS39770C-page 320 BZ Jump = address (HERE) = = = = 1; address (Jump) 0; address (HERE + 2) k7kkk kkkk 110s k19kkk kkkk0 kkkk8 Description: Subroutine call of entire 2-Mbyte memory range. First, return address (PC+ 4) is pushed onto the return stack. If `s' = 1, the W, STATUS and BSR registers are also pushed into their respective shadow registers, WS, STATUSS and BSRS. If `s' = 0, no update occurs. Then, the 20-bit value `k' is loaded into PC<20:1>. CALL is a two-cycle instruction. Words: 2 Cycles: 2 Q Cycle Activity: If Jump: Decode 1110 1111 Q Cycle Activity: Q1 Q2 Q3 Q4 Decode Read literal `k'<7:0>, Push PC to stack Read literal 'k'<19:8>, Write to PC No operation No operation No operation No operation Example: HERE Before Instruction PC = After Instruction PC = TOS = WS = BSRS = STATUSS = CALL THERE,1 address (HERE) address (THERE) address (HERE + 4) W BSR STATUS 2010 Microchip Technology Inc. PIC18F85J90 FAMILY CLRF Clear f Syntax: CLRF Operands: 0 f 255 a [0,1] f {,a} Operation: 000h f, 1Z Status Affected: Z Encoding: 0110 Description: 101a ffff ffff Clears the contents of the specified register. CLRWDT Clear Watchdog Timer Syntax: CLRWDT Operands: None Operation: 000h WDT, 000h WDT postscaler, 1 TO, 1 PD Status Affected: TO, PD Encoding: 0000 Words: 1 Cycles: 1 Q1 Q2 Q3 Q4 Decode Read register `f' Process Data Write register `f' Example: CLRF Before Instruction FLAG_REG After Instruction FLAG_REG FLAG_REG,1 = 5Ah = 00h 2010 Microchip Technology Inc. 0100 Words: 1 Cycles: 1 Q Cycle Activity: Q1 Q2 Q3 Q4 Decode No operation Process Data No operation Example: Q Cycle Activity: 0000 CLRWDT instruction resets the Watchdog Timer. It also resets the postscaler of the WDT. Status bits, TO and PD, are set. If `a' is `0', the Access Bank is selected. If `a' is `1', the BSR is used to select the GPR bank. If `a' is `0' and the extended instruction set is enabled, this instruction operates in Indexed Literal Offset Addressing mode whenever f 95 (5Fh). See Section 24.2.3 "Byte-Oriented and Bit-Oriented Instructions in Indexed Literal Offset Mode" for details. 0000 Description: CLRWDT Before Instruction WDT Counter After Instruction WDT Counter WDT Postscaler TO PD = ? = = = = 00h 0 1 1 DS39770C-page 321 PIC18F85J90 FAMILY COMF Complement f CPFSEQ Compare f with W, Skip if f = W Syntax: COMF Syntax: CPFSEQ Operands: 0 f 255 a [0,1] Operation: (f) - (W), skip if (f) = (W) (unsigned comparison) Status Affected: None f {,d {,a}} Operands: 0 f 255 d [0,1] a [0,1] Operation: f dest Status Affected: N, Z Encoding: 0001 Description: 11da ffff ffff The contents of register `f' are complemented. If `d' is `0', the result is stored in W. If `d' is `1', the result is stored back in register `f'. Encoding: Description: If `a' is `0' and the extended instruction set is enabled, this instruction operates in Indexed Literal Offset Addressing mode whenever f 95 (5Fh). See Section 24.2.3 "Byte-Oriented and Bit-Oriented Instructions in Indexed Literal Offset Mode" for details. 1 Cycles: 1 Q Cycle Activity: Q1 Decode Q2 Read register `f' Example: COMF Before Instruction REG = After Instruction REG = W = 13h 13h ECh Q3 Process Data REG, 0, 0 ffff ffff If `a' is `0', the Access Bank is selected. If `a' is `1', the BSR is used to select the GPR bank. If `a' is `0' and the extended instruction set is enabled, this instruction operates in Indexed Literal Offset Addressing mode whenever f 95 (5Fh). See Section 24.2.3 "Byte-Oriented and Bit-Oriented Instructions in Indexed Literal Offset Mode" for details. Q4 Words: 1 Write to destination Cycles: 1(2) Note: 3 cycles if skip and followed by a 2-word instruction. Q Cycle Activity: Q1 Decode Q2 Read register `f' Q3 Process Data Q4 No operation If skip: Q1 Q2 Q3 No No No operation operation operation If skip and followed by 2-word instruction: Q1 Q2 Q3 No No No operation operation operation No No No operation operation operation Example: HERE NEQUAL EQUAL Before Instruction PC Address W REG After Instruction If REG PC If REG PC DS39770C-page 322 001a Compares the contents of data memory location `f' to the contents of W by performing an unsigned subtraction. If `f' = W, then the fetched instruction is discarded and a NOP is executed instead, making this a two-cycle instruction. If `a' is `0', the Access Bank is selected. If `a' is `1', the BSR is used to select the GPR bank. Words: 0110 f {,a} Q4 No operation Q4 No operation No operation CPFSEQ REG, 0 : : = = = HERE ? ? = = = W; Address (EQUAL) W; Address (NEQUAL) 2010 Microchip Technology Inc. PIC18F85J90 FAMILY CPFSGT Compare f with W, Skip if f > W CPFSLT Compare f with W, Skip if f < W Syntax: CPFSGT Syntax: CPFSLT Operands: 0 f 255 a [0,1] Operands: 0 f 255 a [0,1] Operation: (f) -W), skip if (f) > (W) (unsigned comparison) Operation: (f) -W), skip if (f) < (W) (unsigned comparison) Status Affected: None Status Affected: None Encoding: Description: 0110 f {,a} 010a ffff ffff Compares the contents of data memory location `f' to the contents of the W by performing an unsigned subtraction. Encoding: 0110 Description: If the contents of `f' are greater than the contents of WREG, then the fetched instruction is discarded and a NOP is executed instead, making this a two-cycle instruction. Words: 1 Cycles: 1(2) Note: Q Cycle Activity: Q1 Decode 3 cycles if skip and followed by a 2-word instruction. Q2 Read register `f' Q3 Process Data Q4 No operation Example: HERE NGREATER GREATER Before Instruction PC W After Instruction If REG PC If REG PC Q4 No operation Q4 No operation No operation CPFSGT REG, 0 : : = = Address (HERE) ? = = W; Address (GREATER) W; Address (NGREATER) 2010 Microchip Technology Inc. ffff ffff Compares the contents of data memory location `f' to the contents of W by performing an unsigned subtraction. If `a' is `0', the Access Bank is selected. If `a' is `1', the BSR is used to select the GPR bank. Words: 1 Cycles: 1(2) Note: 3 cycles if skip and followed by a 2-word instruction. Q Cycle Activity: Q1 Q2 Q3 Q4 Decode Read register `f' Process Data No operation If skip: Q1 Q2 Q3 Q4 No operation No operation No operation No operation If skip and followed by 2-word instruction: Q1 Q2 Q3 Q4 No operation No operation No operation No operation No operation No operation No operation No operation If skip: Q1 Q2 Q3 No No No operation operation operation If skip and followed by 2-word instruction: Q1 Q2 Q3 No No No operation operation operation No No No operation operation operation 000a If the contents of `f' are less than the contents of W, then the fetched instruction is discarded and a NOP is executed instead, making this a two-cycle instruction. If `a' is `0', the Access Bank is selected. If `a' is `1', the BSR is used to select the GPR bank. If `a' is `0' and the extended instruction set is enabled, this instruction operates in Indexed Literal Offset Addressing mode whenever f 95 (5Fh). See Section 24.2.3 "Byte-Oriented and Bit-Oriented Instructions in Indexed Literal Offset Mode" for details. f {,a} Example: HERE NLESS LESS Before Instruction PC W After Instruction If REG PC If REG PC CPFSLT REG, 1 : : = = Address (HERE) ? < = = W; Address (LESS) W; Address (NLESS) DS39770C-page 323 PIC18F85J90 FAMILY DAW Decimal Adjust W Register DECF Decrement f Syntax: DAW Syntax: DECF f {,d {,a}} Operands: None Operands: Operation: If [W<3:0> > 9] or [DC = 1], then (W<3:0>) + 6 W<3:0>; else (W<3:0>) W<3:0> 0 f 255 d [0,1] a [0,1] Operation: (f) - 1 dest Status Affected: C, DC, N, OV, Z Encoding: If [W<7:4> > 9] or [C = 1], then (W<7:4>) + 6 W<7:4>; C =1; else (W<7:4>) W<7:4> Status Affected: 0000 Description: 0000 0000 0000 0111 Description: DAW adjusts the eight-bit value in W, resulting from the earlier addition of two variables (each in packed BCD format) and produces a correct packed BCD result. Words: 1 Cycles: 1 Q Cycle Activity: Q1 Q2 Q3 Q4 Decode Read register W Process Data Write W Example 1: A5h 0 0 05h 1 0 ffff Decrement register `f'. If `d' is `0', the result is stored in W. If `d' is `1', the result is stored back in register `f'. If `a' is `0' and the extended instruction set is enabled, this instruction operates in Indexed Literal Offset Addressing mode whenever f 95 (5Fh). See Section 24.2.3 "Byte-Oriented and Bit-Oriented Instructions in Indexed Literal Offset Mode" for details. Words: 1 Cycles: 1 Q Cycle Activity: Q1 Q2 Q3 Q4 Decode Read register `f' Process Data Write to destination DAW Before Instruction W = C = DC = After Instruction W = C = DC = ffff If `a' is `0', the Access Bank is selected. If `a' is `1', the BSR is used to select the GPR bank. C Encoding: 01da Example: DECF Before Instruction CNT = Z = After Instruction CNT = Z = CNT, 1, 0 01h 0 00h 1 Example 2: Before Instruction W = C = DC = After Instruction W = C = DC = DS39770C-page 324 CEh 0 0 34h 1 0 2010 Microchip Technology Inc. PIC18F85J90 FAMILY DECFSZ Decrement f, Skip if 0 DCFSNZ Decrement f, Skip if Not 0 Syntax: DECFSZ f {,d {,a}} Syntax: DCFSNZ Operands: 0 f 255 d [0,1] a [0,1] Operands: 0 f 255 d [0,1] a [0,1] Operation: (f) - 1 dest, skip if result = 0 Operation: (f) - 1 dest, skip if result 0 Status Affected: None Status Affected: None Encoding: 0010 Description: 11da ffff ffff The contents of register `f' are decremented. If `d' is `0', the result is placed in W. If `d' is `1', the result is placed back in register `f'. Encoding: 0100 Description: If the result is `0', the next instruction which is already fetched is discarded and a NOP is executed instead, making it a two-cycle instruction. Cycles: 1(2) Note: 3 cycles if skip and followed by a 2-word instruction. Q1 Q2 Q3 Q4 Read register `f' Process Data Write to destination Q1 Q2 Q3 Q4 No operation No operation No operation No operation Words: 1 Cycles: 1(2) Note: Q1 Q2 Q3 Q4 No operation No operation No operation No operation No operation No operation No operation No operation DECFSZ GOTO CNT, 1, 1 LOOP Example: HERE CONTINUE Before Instruction PC = After Instruction CNT = If CNT = PC = If CNT PC = Address (HERE) CNT - 1 0; Address (CONTINUE) 0; Address (HERE + 2) 2010 Microchip Technology Inc. 3 cycles if skip and followed by a 2-word instruction. Q Cycle Activity: Q1 Q2 Q3 Q4 Decode Read register `f' Process Data Write to destination If skip: If skip and followed by 2-word instruction: ffff If `a' is `0' and the extended instruction set is enabled, this instruction operates in Indexed Literal Offset Addressing mode whenever f 95 (5Fh). See Section 24.2.3 "Byte-Oriented and Bit-Oriented Instructions in Indexed Literal Offset Mode" for details. Q Cycle Activity: Decode ffff If `a' is `0', the Access Bank is selected. If `a' is `1', the BSR is used to select the GPR bank. If `a' is `0' and the extended instruction set is enabled, this instruction operates in Indexed Literal Offset Addressing mode whenever f 95 (5Fh). See Section 24.2.3 "Byte-Oriented and Bit-Oriented Instructions in Indexed Literal Offset Mode" for details. 1 11da The contents of register `f' are decremented. If `d' is `0', the result is placed in W. If `d' is `1', the result is placed back in register `f'. If the result is not `0', the next instruction which is already fetched is discarded and a NOP is executed instead, making it a two-cycle instruction. If `a' is `0', the Access Bank is selected. If `a' is `1', the BSR is used to select the GPR bank. Words: f {,d {,a}} If skip: Q1 Q2 Q3 Q4 No operation No operation No operation No operation If skip and followed by 2-word instruction: Q1 Q2 Q3 Q4 No operation No operation No operation No operation No operation No operation No operation No operation Example: HERE ZERO NZERO Before Instruction TEMP After Instruction TEMP If TEMP PC If TEMP PC DCFSNZ : : TEMP, 1, 0 = ? = = = = TEMP - 1, 0; Address (ZERO) 0; Address (NZERO) DS39770C-page 325 PIC18F85J90 FAMILY GOTO Unconditional Branch INCF Increment f Syntax: GOTO k Syntax: INCF Operands: 0 k 1048575 Operands: Operation: k PC<20:1> Status Affected: None 0 f 255 d [0,1] a [0,1] Operation: (f) + 1 dest Status Affected: C, DC, N, OV, Z Encoding: 1st word (k<7:0>) 2nd word(k<19:8>) 1110 1111 1111 k19kkk k7kkk kkkk kkkk0 kkkk8 Description: GOTO allows an unconditional branch anywhere within entire 2-Mbyte memory range. The 20-bit value `k' is loaded into PC<20:1>. GOTO is always a two-cycle instruction. Words: 2 Cycles: 2 Encoding: 0010 Description: Q1 Q2 Q3 Q4 Read literal `k'<7:0>, No operation Read literal `k'<19:8>, Write to PC No operation No operation No operation No operation Example: GOTO THERE After Instruction PC = Address (THERE) ffff ffff The contents of register `f' are incremented. If `d' is `0', the result is placed in W. If `d' is `1', the result is placed back in register `f'. If `a' is `0' and the extended instruction set is enabled, this instruction operates in Indexed Literal Offset Addressing mode whenever f 95 (5Fh). See Section 24.2.3 "Byte-Oriented and Bit-Oriented Instructions in Indexed Literal Offset Mode" for details. Words: 1 Cycles: 1 Q Cycle Activity: Q1 Q2 Q3 Q4 Decode Read register `f' Process Data Write to destination Example: INCF Before Instruction CNT = Z = C = DC = After Instruction CNT = Z = C = DC = DS39770C-page 326 10da If `a' is `0', the Access Bank is selected. If `a' is `1', the BSR is used to select the GPR bank. Q Cycle Activity: Decode f {,d {,a}} CNT, 1, 0 FFh 0 ? ? 00h 1 1 1 2010 Microchip Technology Inc. PIC18F85J90 FAMILY INCFSZ Increment f, Skip if 0 INFSNZ Syntax: INCFSZ Syntax: INFSNZ 0 f 255 d [0,1] a [0,1] f {,d {,a}} Increment f, Skip if Not 0 f {,d {,a}} Operands: 0 f 255 d [0,1] a [0,1] Operands: Operation: (f) + 1 dest, skip if result = 0 Operation: (f) + 1 dest, skip if result 0 Status Affected: None Status Affected: None Encoding: 0011 Description: 11da ffff ffff The contents of register `f' are incremented. If `d' is `0', the result is placed in W. If `d' is `1', the result is placed back in register `f'. Encoding: 0100 Description: 10da ffff ffff The contents of register `f' are incremented. If `d' is `0', the result is placed in W. If `d' is `1', the result is placed back in register `f'. If the result is `0', the next instruction which is already fetched is discarded and a NOP is executed instead, making it a two-cycle instruction. If the result is not `0', the next instruction which is already fetched is discarded and a NOP is executed instead, making it a two-cycle instruction. If `a' is `0', the Access Bank is selected. If `a' is `1', the BSR is used to select the GPR bank. If `a' is `0', the Access Bank is selected. If `a' is `1', the BSR is used to select the GPR bank. If `a' is `0' and the extended instruction set is enabled, this instruction operates in Indexed Literal Offset Addressing mode whenever f 95 (5Fh). See Section 24.2.3 "Byte-Oriented and Bit-Oriented Instructions in Indexed Literal Offset Mode" for details. If `a' is `0' and the extended instruction set is enabled, this instruction operates in Indexed Literal Offset Addressing mode whenever f 95 (5Fh). See Section 24.2.3 "Byte-Oriented and Bit-Oriented Instructions in Indexed Literal Offset Mode" for details. Words: 1 Words: 1 Cycles: 1(2) Note: Cycles: 1(2) Note: 3 cycles if skip and followed by a 2-word instruction. 3 cycles if skip and followed by a 2-word instruction. Q Cycle Activity: Q Cycle Activity: Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Decode Read register `f' Process Data Write to destination Decode Read register `f' Process Data Write to destination Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 No operation No operation No operation No operation No operation No operation No operation No operation If skip: If skip: If skip and followed by 2-word instruction: If skip and followed by 2-word instruction: Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 No operation No operation No operation No operation No operation No operation No operation No operation No operation No operation No operation No operation No operation No operation No operation No operation Example: HERE NZERO ZERO Before Instruction PC = After Instruction CNT = If CNT = PC = If CNT PC = INCFSZ : : Address (HERE) CNT + 1 0; Address (ZERO) 0; Address (NZERO) 2010 Microchip Technology Inc. CNT, 1, 0 Example: HERE ZERO NZERO Before Instruction PC = After Instruction REG = If REG PC = If REG = PC = INFSNZ REG, 1, 0 Address (HERE) REG + 1 0; Address (NZERO) 0; Address (ZERO) DS39770C-page 327 PIC18F85J90 FAMILY IORLW Inclusive OR Literal with W IORWF Inclusive OR W with f Syntax: IORLW k Syntax: IORWF Operands: 0 k 255 Operands: Operation: (W) .OR. k W Status Affected: N, Z 0 f 255 d [0,1] a [0,1] Operation: (W) .OR. (f) dest Status Affected: N, Z Encoding: 0000 1001 kkkk kkkk Description: The contents of W are ORed with the eight-bit literal `k'. The result is placed in W. Words: 1 Cycles: 1 Encoding: 0001 Description: Q1 Q2 Q3 Q4 Read literal `k' Process Data Write to W Example: IORLW Before Instruction W = After Instruction W = ffff ffff Inclusive OR W with register `f'. If `d' is `0', the result is placed in W. If `d' is `1', the result is placed back in register `f'. If `a' is `0' and the extended instruction set is enabled, this instruction operates in Indexed Literal Offset Addressing mode whenever f 95 (5Fh). See Section 24.2.3 "Byte-Oriented and Bit-Oriented Instructions in Indexed Literal Offset Mode" for details. 35h 9Ah BFh 00da If `a' is `0', the Access Bank is selected. If `a' is `1', the BSR is used to select the GPR bank. Q Cycle Activity: Decode f {,d {,a}} Words: 1 Cycles: 1 Q Cycle Activity: Q1 Q2 Q3 Q4 Decode Read register `f' Process Data Write to destination Example: IORWF Before Instruction RESULT = W = After Instruction RESULT = W = DS39770C-page 328 RESULT, 0, 1 13h 91h 13h 93h 2010 Microchip Technology Inc. PIC18F85J90 FAMILY LFSR Load FSR MOVF Move f Syntax: LFSR f, k Syntax: MOVF Operands: 0f2 0 k 4095 Operands: Operation: k FSRf 0 f 255 d [0,1] a [0,1] Status Affected: None Operation: f dest Status Affected: N, Z Encoding: 1110 1111 1110 0000 00ff k7kkk k11kkk kkkk Description: The 12-bit literal `k' is loaded into the file select register pointed to by `f'. Words: 2 Cycles: 2 Encoding: 0101 Description: Q Cycle Activity: Q1 Q2 Q3 Q4 Decode Read literal `k' MSB Process Data Write literal `k' MSB to FSRfH Decode Read literal `k' LSB Process Data Write literal `k' to FSRfL Example: After Instruction FSR2H FSR2L 03h ABh 00da ffff ffff The contents of register `f' are moved to a destination dependent upon the status of `d'. If `d' is `0', the result is placed in W. If `d' is `1', the result is placed back in register `f'. Location `f' can be anywhere in the 256-byte bank. If `a' is `0', the Access Bank is selected. If `a' is `1', the BSR is used to select the GPR bank. If `a' is `0' and the extended instruction set is enabled, this instruction operates in Indexed Literal Offset Addressing mode whenever f 95 (5Fh). See Section 24.2.3 "Byte-Oriented and Bit-Oriented Instructions in Indexed Literal Offset Mode" for details. LFSR 2, 3ABh = = f {,d {,a}} Words: 1 Cycles: 1 Q Cycle Activity: Q1 Q2 Q3 Q4 Decode Read register `f' Process Data Write W Example: MOVF Before Instruction REG W After Instruction REG W 2010 Microchip Technology Inc. REG, 0, 0 = = 22h FFh = = 22h 22h DS39770C-page 329 PIC18F85J90 FAMILY MOVFF Move f to f MOVLB Move Literal to Low Nibble in BSR Syntax: MOVFF fs,fd Syntax: MOVLW k Operands: 0 fs 4095 0 fd 4095 Operands: 0 k 255 Operation: k BSR Status Affected: None Operation: (fs) fd Status Affected: None Encoding: 1st word (source) 2nd word (destin.) Encoding: 1100 1111 Description: ffff ffff ffff ffff ffffs ffffd The contents of source register `fs' are moved to destination register `fd'. Location of source `fs' can be anywhere in the 4096-byte data space (000h to FFFh) and location of destination `fd' can also be anywhere from 000h to FFFh. Either source or destination can be W (a useful special situation). MOVFF is particularly useful for transferring a data memory location to a peripheral register (such as the transmit buffer or an I/O port). The MOVFF instruction cannot use the PCL, TOSU, TOSH or TOSL as the destination register Words: 2 Cycles: 2 0000 0001 kkkk kkkk Description: The eight-bit literal `k' is loaded into the Bank Select Register (BSR). The value of BSR<7:4> always remains `0' regardless of the value of k7:k4. Words: 1 Cycles: 1 Q Cycle Activity: Q1 Q2 Q3 Q4 Decode Read literal `k' Process Data Write literal `k' to BSR MOVLB 5 Example: Before Instruction BSR Register = After Instruction BSR Register = 02h 05h Q Cycle Activity: Q1 Q2 Q3 Q4 Decode Read register `f' (src) Process Data No operation Decode No operation No operation Write register `f' (dest) No dummy read Example: MOVFF Before Instruction REG1 REG2 After Instruction REG1 REG2 DS39770C-page 330 REG1, REG2 = = 33h 11h = = 33h 33h 2010 Microchip Technology Inc. PIC18F85J90 FAMILY MOVLW Move Literal to W MOVWF Move W to f Syntax: MOVLW k Syntax: MOVWF Operands: 0 k 255 Operands: Operation: kW 0 f 255 a [0,1] Status Affected: None Encoding: 0000 Description: 1110 kkkk kkkk The eight-bit literal `k' is loaded into W. Words: 1 Cycles: 1 Operation: (W) f Status Affected: None Encoding: 0110 Description: Q Cycle Activity: Q1 Q2 Q3 Q4 Decode Read literal `k' Process Data Write to W Example: After Instruction W = MOVLW f {,a} 111a ffff ffff Move data from W to register `f'. Location `f' can be anywhere in the 256-byte bank. If `a' is `0', the Access Bank is selected. If `a' is `1', the BSR is used to select the GPR bank. If `a' is `0' and the extended instruction set is enabled, this instruction operates in Indexed Literal Offset Addressing mode whenever f 95 (5Fh). See Section 24.2.3 "Byte-Oriented and Bit-Oriented Instructions in Indexed Literal Offset Mode" for details. 5Ah 5Ah Words: 1 Cycles: 1 Q Cycle Activity: Q1 Q2 Q3 Q4 Decode Read register `f' Process Data Write register `f' Example: MOVWF Before Instruction W = REG = After Instruction W = REG = 2010 Microchip Technology Inc. REG, 0 4Fh FFh 4Fh 4Fh DS39770C-page 331 PIC18F85J90 FAMILY MULLW Multiply Literal with W MULWF Syntax: MULLW Syntax: MULWF Operands: 0 k 255 Operands: Operation: (W) x k PRODH:PRODL 0 f 255 a [0,1] Status Affected: None Operation: (W) x (f) PRODH:PRODL Status Affected: None Encoding: 0000 Description: k 1101 kkkk kkkk An unsigned multiplication is carried out between the contents of W and the 8-bit literal `k'. The 16-bit result is placed in the PRODH:PRODL register pair. PRODH contains the high byte. Multiply W with f Encoding: 0000 Description: W is unchanged. None of the Status flags are affected. 1 Cycles: 1 Q1 Q2 Q3 Q4 Read literal `k' Process Data Write registers PRODH: PRODL MULLW 0C4h = = = E2h ? ? = = = E2h ADh 08h If `a' is `0' and the extended instruction set is enabled, this instruction operates in Indexed Literal Offset Addressing mode whenever f 95 (5Fh). See Section 24.2.3 "Byte-Oriented and Bit-Oriented Instructions in Indexed Literal Offset Mode" for details. Words: 1 Cycles: 1 Q Cycle Activity: Q1 Q2 Q3 Q4 Decode Read register `f' Process Data Write registers PRODH: PRODL Example: Before Instruction W REG PRODH PRODL After Instruction W REG PRODH PRODL DS39770C-page 332 ffff If `a' is `0', the Access Bank is selected. If `a' is `1', the BSR is used to select the GPR bank. Decode Before Instruction W PRODH PRODL After Instruction W PRODH PRODL ffff Note that neither Overflow nor Carry is possible in this operation. A Zero result is possible but not detected. Q Cycle Activity: Example: 001a An unsigned multiplication is carried out between the contents of W and the register file location `f'. The 16-bit result is stored in the PRODH:PRODL register pair. PRODH contains the high byte. Both W and `f' are unchanged. None of the Status flags are affected. Note that neither Overflow nor Carry is possible in this operation. A Zero result is possible but not detected. Words: f {,a} MULWF REG, 1 = = = = C4h B5h ? ? = = = = C4h B5h 8Ah 94h 2010 Microchip Technology Inc. PIC18F85J90 FAMILY NEGF Negate f Syntax: NEGF Operands: 0 f 255 a [0,1] f {,a} Operation: (f) + 1 f Status Affected: N, OV, C, DC, Z Encoding: 0110 Description: 110a ffff If `a' is `0' and the extended instruction set is enabled, this instruction operates in Indexed Literal Offset Addressing mode whenever f 95 (5Fh). See Section 24.2.3 "Byte-Oriented and Bit-Oriented Instructions in Indexed Literal Offset Mode" for details. 1 1 Syntax: NOP Operands: None Operation: No operation Status Affected: None 0000 1111 ffff If `a' is `0', the Access Bank is selected. If `a' is `1', the BSR is used to select the GPR bank. Cycles: No Operation Encoding: Location `f' is negated using two's complement. The result is placed in the data memory location `f'. Words: NOP 0000 xxxx Description: No operation. Words: 1 Cycles: 1 0000 xxxx 0000 xxxx Q Cycle Activity: Q1 Q2 Q3 Q4 Decode No operation No operation No operation Example: None. Q Cycle Activity: Q1 Q2 Q3 Q4 Decode Read register `f' Process Data Write register `f' Example: NEGF Before Instruction REG = After Instruction REG = REG, 1 0011 1010 [3Ah] 1100 0110 [C6h] 2010 Microchip Technology Inc. DS39770C-page 333 PIC18F85J90 FAMILY POP Pop Top of Return Stack PUSH Push Top of Return Stack Syntax: POP Syntax: PUSH Operands: None Operands: None Operation: (TOS) bit bucket Operation: (PC + 2) TOS Status Affected: None Status Affected: None Encoding: 0000 0000 0000 0110 Encoding: 0000 0000 0000 0101 Description: The TOS value is pulled off the return stack and is discarded. The TOS value then becomes the previous value that was pushed onto the return stack. This instruction is provided to enable the user to properly manage the return stack to incorporate a software stack. Description: The PC + 2 is pushed onto the top of the return stack. The previous TOS value is pushed down on the stack. This instruction allows implementing a software stack by modifying TOS and then pushing it onto the return stack. Words: 1 Words: 1 Cycles: 1 Cycles: 1 Q Cycle Activity: Q Cycle Activity: Q1 Q2 Q3 Q4 Decode No operation POP TOS value No operation POP GOTO NEW Example: Q2 Q3 Q4 PUSH PC + 2 onto return stack No operation No operation Example: Before Instruction TOS Stack (1 level down) = = 0031A2h 014332h After Instruction TOS PC = = 014332h NEW DS39770C-page 334 Q1 Decode PUSH Before Instruction TOS PC = = 345Ah 0124h After Instruction PC TOS Stack (1 level down) = = = 0126h 0126h 345Ah 2010 Microchip Technology Inc. PIC18F85J90 FAMILY RCALL Relative Call RESET Reset Syntax: RCALL Syntax: RESET n Operands: -1024 n 1023 Operands: None Operation: (PC) + 2 TOS, (PC) + 2 + 2n PC Operation: Reset all registers and flags that are affected by a MCLR Reset. Status Affected: None Status Affected: All Encoding: 1101 Description: 1nnn nnnn nnnn Subroutine call with a jump up to 1K from the current location. First, return address (PC + 2) is pushed onto the stack. Then, add the 2's complement number `2n' to the PC. Since the PC will have incremented to fetch the next instruction, the new address will be PC + 2 + 2n. This instruction is a two-cycle instruction. Words: 1 Cycles: 2 Encoding: 0000 Q1 Q2 Q3 Q4 Decode Read literal `n' Process Data Write to PC No operation No operation 1111 1111 This instruction provides a way to execute a MCLR Reset in software. Words: 1 Cycles: 1 Q Cycle Activity: Q1 Q2 Q3 Q4 Decode Start reset No operation No operation Example: Q Cycle Activity: 0000 Description: After Instruction Registers = Flags* = RESET Reset Value Reset Value PUSH PC to stack No operation Example: No operation HERE RCALL Jump Before Instruction PC = Address (HERE) After Instruction PC = Address (Jump) TOS = Address (HERE + 2) 2010 Microchip Technology Inc. DS39770C-page 335 PIC18F85J90 FAMILY RETFIE Return from Interrupt RETLW Return Literal to W Syntax: RETFIE {s} Syntax: RETLW k Operands: s [0,1] Operands: 0 k 255 Operation: (TOS) PC, 1 GIE/GIEH or PEIE/GIEL; if s = 1 (WS) W, (STATUSS) STATUS, (BSRS) BSR, PCLATU, PCLATH are unchanged Operation: k W, (TOS) PC, PCLATU, PCLATH are unchanged Status Affected: None Status Affected: 0000 0000 Description: 0000 0001 Words: 1 Cycles: 2 Q Cycle Activity: kkkk kkkk W is loaded with the eight-bit literal `k'. The program counter is loaded from the top of the stack (the return address). The high address latch (PCLATH) remains unchanged. Words: 1 Cycles: 2 000s Return from interrupt. Stack is popped and Top-of-Stack (TOS) is loaded into the PC. Interrupts are enabled by setting either the high or low-priority global interrupt enable bit. If `s' = 1, the contents of the shadow registers WS, STATUSS and BSRS are loaded into their corresponding registers W, STATUS and BSR. If `s' = 0, no update of these registers occurs. 1100 Description: GIE/GIEH, PEIE/GIEL. Encoding: Q Cycle Activity: Q1 Q2 Q3 Q4 Decode Read literal `k' Process Data POP PC from stack, write to W No operation No operation No operation No operation Example: Q1 Q2 Q3 Q4 Decode No operation No operation POP PC from stack Set GIEH or GIEL No operation Encoding: No operation Example: RETFIE After Interrupt PC W BSR STATUS GIE/GIEH, PEIE/GIEL DS39770C-page 336 No operation No operation 1 = = = = = TOS WS BSRS STATUSS 1 CALL TABLE ; ; ; ; : TABLE ADDWF PCL ; RETLW k0 ; RETLW k1 ; : : RETLW kn ; Before Instruction W = After Instruction W = W contains table offset value W now has table value W = offset Begin table End of table 07h value of kn 2010 Microchip Technology Inc. PIC18F85J90 FAMILY RETURN Return from Subroutine RLCF Rotate Left f through Carry Syntax: RETURN {s} Syntax: RLCF Operands: s [0,1] Operands: Operation: (TOS) PC; if s = 1 (WS) W, (STATUSS) STATUS, (BSRS) BSR, PCLATU, PCLATH are unchanged 0 f 255 d [0,1] a [0,1] Operation: (f<n>) dest<n + 1>, (f<7>) C, (C) dest<0> Status Affected: C, N, Z Status Affected: None Encoding: 0000 Description: Encoding: 0000 0001 001s 0011 Description: Return from subroutine. The stack is popped and the top of the stack (TOS) is loaded into the program counter. If `s'= 1, the contents of the shadow registers WS, STATUSS and BSRS are loaded into their corresponding registers W, STATUS and BSR. If `s' = 0, no update of these registers occurs. Words: 1 Cycles: 2 Q1 Q2 Q3 Q4 No operation Process Data POP PC from stack No operation No operation No operation No operation 01da ffff ffff The contents of register `f' are rotated one bit to the left through the Carry flag. If `d' is `0', the result is placed in W. If `d' is `1', the result is stored back in register `f'. If `a' is `0', the Access Bank is selected. If `a' is `1', the BSR is used to select the GPR bank. If `a' is `0' and the extended instruction set is enabled, this instruction operates in Indexed Literal Offset Addressing mode whenever f 95 (5Fh). See Section 24.2.3 "Byte-Oriented and Bit-Oriented Instructions in Indexed Literal Offset Mode" for details. Q Cycle Activity: Decode f {,d {,a}} register f C Words: 1 Cycles: 1 Q Cycle Activity: Example: Q1 Q2 Q3 Q4 Decode Read register `f' Process Data Write to destination RETURN After Instruction: PC = TOS Example: Before Instruction REG = C = After Instruction REG = W = C = 2010 Microchip Technology Inc. RLCF REG, 0, 0 1110 0110 0 1110 0110 1100 1100 1 DS39770C-page 337 PIC18F85J90 FAMILY RLNCF Rotate Left f (No Carry) RRCF Rotate Right f through Carry Syntax: RLNCF Syntax: RRCF Operands: 0 f 255 d [0,1] a [0,1] Operands: 0 f 255 d [0,1] a [0,1] Operation: (f<n>) dest<n + 1>, (f<7>) dest<0> Operation: Status Affected: N, Z (f<n>) dest<n - 1>, (f<0>) C, (C) dest<7> Status Affected: C, N, Z Encoding: 0100 Description: f {,d {,a}} 01da ffff ffff The contents of register `f' are rotated one bit to the left. If `d' is `0', the result is placed in W. If `d' is `1', the result is stored back in register `f'. Encoding: 0011 Description: If `a' is `0', the Access Bank is selected. If `a' is `1', the BSR is used to select the GPR bank. 1 1 Q1 Decode Q2 Read register `f' Example: Before Instruction REG = After Instruction REG = DS39770C-page 338 RLNCF Q3 Process Data Q4 Write to destination Words: 1 Cycles: register f 1 Q Cycle Activity: Q1 Q2 Q3 Q4 Decode Read register `f' Process Data Write to destination REG, 1, 0 1010 1011 0101 0111 ffff The contents of register `f' are rotated one bit to the right through the Carry flag. If `d' is `0', the result is placed in W. If `d' is `1', the result is placed back in register `f'. C Q Cycle Activity: ffff If `a' is `0' and the extended instruction set is enabled, this instruction operates in Indexed Literal Offset Addressing mode whenever f 95 (5Fh). See Section 24.2.3 "Byte-Oriented and Bit-Oriented Instructions in Indexed Literal Offset Mode" for details. register f Cycles: 00da If `a' is `0', the Access Bank is selected. If `a' is `1', the BSR is used to select the GPR bank. If `a' is `0' and the extended instruction set is enabled, this instruction operates in Indexed Literal Offset Addressing mode whenever f 95 (5Fh). See Section 24.2.3 "Byte-Oriented and Bit-Oriented Instructions in Indexed Literal Offset Mode" for details. Words: f {,d {,a}} Example: RRCF Before Instruction REG = C = After Instruction REG = W = C = REG, 0, 0 1110 0110 0 1110 0110 0111 0011 0 2010 Microchip Technology Inc. PIC18F85J90 FAMILY RRNCF Rotate Right f (No Carry) SETF Set f Syntax: RRNCF Syntax: SETF Operands: 0 f 255 d [0,1] a [0,1] Operands: 0 f 255 a [0,1] Operation: (f<n>) dest<n - 1>, (f<0>) dest<7> Status Affected: N, Z Encoding: 0100 Description: f {,d {,a}} 00da Operation: FFh f Status Affected: None Encoding: ffff ffff 0110 Description: The contents of register `f' are rotated one bit to the right. If `d' is `0', the result is placed in W. If `d' is `1', the result is placed back in register `f'. register f Words: 1 Cycles: 1 Q1 Q2 Q3 Q4 Decode Read register `f' Process Data Write to destination Example 1: RRNCF Before Instruction REG = After Instruction REG = Example 2: ffff Words: 1 Cycles: 1 Q Cycle Activity: Q1 Q2 Q3 Q4 Decode Read register `f' Process Data Write register `f' SETF Before Instruction REG After Instruction REG REG,1 = 5Ah = FFh REG, 1, 0 1101 0111 1110 1011 RRNCF Before Instruction W = REG = After Instruction W = REG = ffff If `a' is `0' and the extended instruction set is enabled, this instruction operates in Indexed Literal Offset Addressing mode whenever f 95 (5Fh). See Section 24.2.3 "Byte-Oriented and Bit-Oriented Instructions in Indexed Literal Offset Mode" for details. Example: Q Cycle Activity: 100a The contents of the specified register are set to FFh. If `a' is `0', the Access Bank is selected. If `a' is `1', the BSR is used to select the GPR bank. If `a' is `0', the Access Bank will be selected, overriding the BSR value. If `a' is `1', then the bank will be selected as per the BSR value. If `a' is `0' and the extended instruction set is enabled, this instruction operates in Indexed Literal Offset Addressing mode whenever f 95 (5Fh). See Section 24.2.3 "Byte-Oriented and Bit-Oriented Instructions in Indexed Literal Offset Mode" for details. f {,a} REG, 0, 0 ? 1101 0111 1110 1011 1101 0111 2010 Microchip Technology Inc. DS39770C-page 339 PIC18F85J90 FAMILY SLEEP Enter Sleep Mode SUBFWB Subtract f from W with Borrow Syntax: SLEEP Syntax: SUBFWB Operands: None Operands: Operation: 00h WDT, 0 WDT postscaler, 1 TO, 0 PD 0 f 255 d [0,1] a [0,1] Operation: (W) - (f) - (C) dest Status Affected: N, OV, C, DC, Z Status Affected: TO, PD Encoding: 0000 Description: Encoding: 0000 0000 0011 0101 Description: The Power-Down status bit (PD) is cleared. The Time-out status bit (TO) is set. The Watchdog Timer and its postscaler are cleared. The processor is put into Sleep mode with the oscillator stopped. Words: 1 Cycles: 1 Q1 Q2 Q3 Q4 No operation Process Data Go to Sleep Example: SLEEP Before Instruction TO = ? ? PD = After Instruction 1 TO = PD = 0 If WDT causes wake-up, this bit is cleared. DS39770C-page 340 01da ffff ffff Subtract register `f' and Carry flag (borrow) from W (2's complement method). If `d' is `0', the result is stored in W. If `d' is `1', the result is stored in register `f'. If `a' is `0', the Access Bank is selected. If `a' is `1', the BSR is used to select the GPR bank. If `a' is `0' and the extended instruction set is enabled, this instruction operates in Indexed Literal Offset Addressing mode whenever f 95 (5Fh). See Section 24.2.3 "Byte-Oriented and Bit-Oriented Instructions in Indexed Literal Offset Mode" for details. Q Cycle Activity: Decode f {,d {,a}} Words: 1 Cycles: 1 Q Cycle Activity: Q1 Q2 Q3 Q4 Decode Read register `f' Process Data Write to destination SUBFWB REG, 1, 0 Example 1: Before Instruction REG = 3 W = 2 C = 1 After Instruction REG = FF W = 2 C = 0 Z = 0 N = 1 ; result is negative SUBFWB REG, 0, 0 Example 2: Before Instruction REG = 2 W = 5 C = 1 After Instruction REG = 2 W = 3 C = 1 Z = 0 N = 0 ; result is positive SUBFWB REG, 1, 0 Example 3: Before Instruction REG = 1 W = 2 C = 0 After Instruction REG = 0 W = 2 C = 1 Z = 1 ; result is zero N = 0 2010 Microchip Technology Inc. PIC18F85J90 FAMILY SUBLW Subtract W from Literal SUBWF Subtract W from f Syntax: SUBLW k Syntax: SUBWF Operands: 0 k 255 Operands: Operation: k - (W) W Status Affected: N, OV, C, DC, Z 0 f 255 d [0,1] a [0,1] Operation: (f) - (W) dest Status Affected: N, OV, C, DC, Z Encoding: 0000 1000 kkkk kkkk Description: W is subtracted from the eight-bit literal `k'. The result is placed in W. Words: 1 Cycles: 1 Encoding: 0101 Description: Q Cycle Activity: Q1 Q2 Q3 Q4 Decode Read literal `k' Process Data Write to W Example 1: Before Instruction W = C = After Instruction W = C = Z = N = Example 2: Before Instruction W = C = After Instruction W = C = Z = N = Example 3: Before Instruction W = C = After Instruction W = C = Z = N = SUBLW SUBLW ; result is positive 02h ? 00h 1 1 0 SUBLW ; result is zero 02h 03h ? FFh 0 0 1 ; (2's complement) ; result is negative ffff Subtract W from register `f' (2's complement method). If `d' is `0', the result is stored in W. If `d' is `1', the result is stored back in register `f'. Words: 1 Cycles: 1 Q Cycle Activity: Q1 Q2 Q3 Q4 Decode Read register `f' Process Data Write to destination SUBWF REG, 1, 0 Example 1: Before Instruction REG = W = C = After Instruction REG = W = C = Z = N = Example 2: Before Instruction REG = W = C = After Instruction REG = W = C = Z = N = Example 3: Before Instruction REG = W = C = After Instruction REG = W = C = Z = N = 2010 Microchip Technology Inc. ffff If `a' is `0' and the extended instruction set is enabled, this instruction operates in Indexed Literal Offset Addressing mode whenever f 95 (5Fh). See Section 24.2.3 "Byte-Oriented and Bit-Oriented Instructions in Indexed Literal Offset Mode" for details. 02h 02h 11da If `a' is `0', the Access Bank is selected. If `a' is `1', the BSR is used to select the GPR bank. 01h ? 01h 1 0 0 f {,d {,a}} 3 2 ? 1 2 1 0 0 ; result is positive SUBWF REG, 0, 0 2 2 ? 2 0 1 1 0 SUBWF ; result is zero REG, 1, 0 1 2 ? FFh ;(2's complement) 2 0 ; result is negative 0 1 DS39770C-page 341 PIC18F85J90 FAMILY SUBWFB Subtract W from f with Borrow SWAPF Swap f Syntax: SUBWFB Syntax: SWAPF f {,d {,a}} Operands: 0 f 255 d [0,1] a [0,1] Operands: 0 f 255 d [0,1] a [0,1] Operation: (f) - (W) - (C) dest Operation: Status Affected: N, OV, C, DC, Z (f<3:0>) dest<7:4>, (f<7:4>) dest<3:0> Status Affected: None Encoding: 0101 Description: f {,d {,a}} 10da ffff ffff Subtract W and the Carry flag (borrow) from register `f' (2's complement method). If `d' is `0', the result is stored in W. If `d' is `1', the result is stored back in register `f'. Encoding: 0011 Description: If `a' is `0', the Access Bank is selected. If `a' is `1', the BSR is used to select the GPR bank. 1 Cycles: 1 Q Cycle Activity: Q1 Decode Q2 Read register `f' Example 1: SUBWFB Before Instruction REG = W = C = After Instruction REG = W = C = Z = N = Example 2: Q4 Write to destination If `a' is `0' and the extended instruction set is enabled, this instruction operates in Indexed Literal Offset Addressing mode whenever f 95 (5Fh). See Section 24.2.3 "Byte-Oriented and Bit-Oriented Instructions in Indexed Literal Offset Mode" for details. Words: 1 Cycles: 1 Q Cycle Activity: Q1 Q2 Q3 Q4 Decode Read register `f' Process Data Write to destination REG, 1, 0 19h 0Dh 1 (0001 1001) (0000 1101) 0Ch 0Dh 1 0 0 (0000 1011) (0000 1101) ffff Example: SWAPF Before Instruction REG = After Instruction REG = REG, 1, 0 53h 35h ; result is positive SUBWFB REG, 0, 0 Before Instruction REG = W = C = After Instruction REG = W = C = Z = N = Example 3: 1Bh 1Ah 0 (0001 1011) (0001 1010) 1Bh 00h 1 1 0 (0001 1011) SUBWFB Before Instruction REG = W = C = After Instruction REG = W C Z N Q3 Process Data ffff If `a' is `0', the Access Bank is selected. If `a' is `1', the BSR is used to select the GPR bank. If `a' is `0' and the extended instruction set is enabled, this instruction operates in Indexed Literal Offset Addressing mode whenever f 95 (5Fh). See Section 24.2.3 "Byte-Oriented and Bit-Oriented Instructions in Indexed Literal Offset Mode" for details. Words: 10da The upper and lower nibbles of register `f' are exchanged. If `d' is `0', the result is placed in W. If `d' is `1', the result is placed in register `f'. = = = = DS39770C-page 342 ; result is zero REG, 1, 0 03h 0Eh 1 (0000 0011) (0000 1101) F5h (1111 0100) ; [2's comp] (0000 1101) 0Eh 0 0 1 ; result is negative 2010 Microchip Technology Inc. PIC18F85J90 FAMILY TBLRD Table Read TBLRD Table Read (Continued) Syntax: TBLRD ( *; *+; *-; +*) Example 1: TBLRD Operands: None Operation: if TBLRD *, (Prog Mem (TBLPTR)) TABLAT; TBLPTR - No Change if TBLRD *+, (Prog Mem (TBLPTR)) TABLAT; (TBLPTR) + 1 TBLPTR if TBLRD *-, (Prog Mem (TBLPTR)) TABLAT; (TBLPTR) - 1 TBLPTR if TBLRD +*, (TBLPTR) + 1 TBLPTR; (Prog Mem (TBLPTR)) TABLAT Status Affected: None Encoding: Description: 0000 0000 0000 Before Instruction TABLAT TBLPTR MEMORY(00A356h) After Instruction TABLAT TBLPTR Example 2: TBLRD Before Instruction TABLAT TBLPTR MEMORY(01A357h) MEMORY(01A358h) After Instruction TABLAT TBLPTR *+ ; = = = 55h 00A356h 34h = = 34h 00A357h +* ; = = = = AAh 01A357h 12h 34h = = 34h 01A358h 10nn nn=0 * =1 *+ =2 *=3 +* This instruction is used to read the contents of Program Memory (P.M.). To address the program memory, a pointer called Table Pointer (TBLPTR) is used. The TBLPTR (a 21-bit pointer) points to each byte in the program memory. TBLPTR has a 2-Mbyte address range. TBLPTR[0] = 0: Least Significant Byte of Program Memory Word TBLPTR[0] = 1: Most Significant Byte of Program Memory Word The TBLRD instruction can modify the value of TBLPTR as follows: * no change * post-increment * post-decrement * pre-increment Words: 1 Cycles: 2 Q Cycle Activity: Q1 Q2 Q3 Q4 Decode No operation No operation No operation No operation No operation (Read Program Memory) No operation No operation (Write TABLAT) 2010 Microchip Technology Inc. DS39770C-page 343 PIC18F85J90 FAMILY TBLWT Table Write TBLWT Table Write (Continued) Syntax: TBLWT ( *; *+; *-; +*) Example 1: TBLWT *+; Operands: None Operation: if TBLWT*, (TABLAT) Holding Register; TBLPTR - No Change if TBLWT*+, (TABLAT) Holding Register; (TBLPTR) + 1 TBLPTR if TBLWT*-, (TABLAT) Holding Register; (TBLPTR) - 1 TBLPTR if TBLWT+*, (TBLPTR) + 1 TBLPTR; (TABLAT) Holding Register Status Affected: Example 2: None Encoding: Description: Before Instruction TABLAT = 55h TBLPTR = 00A356h HOLDING REGISTER (00A356h) = FFh After Instructions (table write completion) TABLAT = 55h TBLPTR = 00A357h HOLDING REGISTER (00A356h) = 55h 0000 0000 0000 11nn nn=0 * =1 *+ =2 *=3 +* This instruction uses the 3 LSBs of TBLPTR to determine which of the 8 holding registers the TABLAT is written to. The holding registers are used to program the contents of Program Memory (P.M.). (Refer to Section 6.0 "Memory Organization" for additional details on programming Flash memory.) TBLWT +*; Before Instruction TABLAT = 34h TBLPTR = 01389Ah HOLDING REGISTER (01389Ah) = FFh HOLDING REGISTER (01389Bh) = FFh After Instruction (table write completion) TABLAT = 34h TBLPTR = 01389Bh HOLDING REGISTER (01389Ah) = FFh HOLDING REGISTER (01389Bh) = 34h The TBLPTR (a 21-bit pointer) points to each byte in the program memory. TBLPTR has a 2-Mbyte address range. The LSb of the TBLPTR selects which byte of the program memory location to access. TBLPTR[0] = 0: Least Significant Byte of Program Memory Word TBLPTR[0] = 1: Most Significant Byte of Program Memory Word The TBLWT instruction can modify the value of TBLPTR as follows: * * * * no change post-increment post-decrement pre-increment Words: 1 Cycles: 2 Q Cycle Activity: Q1 Decode Q2 Q3 Q4 No No No operation operation operation No No No No operation operation operation operation (Read (Write to TABLAT) Holding Register) DS39770C-page 344 2010 Microchip Technology Inc. PIC18F85J90 FAMILY TSTFSZ Test f, Skip if 0 XORLW Exclusive OR Literal with W Syntax: TSTFSZ f {,a} Syntax: XORLW k Operands: 0 f 255 a [0,1] Operands: 0 k 255 Operation: (W) .XOR. k W Status Affected: N, Z Operation: skip if f = 0 Status Affected: None Encoding: Encoding: 0110 Description: 011a ffff ffff If `f' = 0, the next instruction fetched during the current instruction execution is discarded and a NOP is executed, making this a two-cycle instruction. If `a' is `0', the Access Bank is selected. If `a' is `1', the BSR is used to select the GPR bank. If `a' is `0' and the extended instruction set is enabled, this instruction operates in Indexed Literal Offset Addressing mode whenever f 95 (5Fh). See Section 24.2.3 "Byte-Oriented and Bit-Oriented Instructions in Indexed Literal Offset Mode" for details. Words: 1 Cycles: 1(2) Note: 3 cycles if skip and followed by a 2-word instruction. 0000 1010 kkkk kkkk Description: The contents of W are XORed with the 8-bit literal `k'. The result is placed in W. Words: 1 Cycles: 1 Q Cycle Activity: Q1 Q2 Q3 Q4 Decode Read literal `k' Process Data Write to W Example: Before Instruction W = After Instruction W = XORLW 0AFh B5h 1Ah Q Cycle Activity: Q1 Q2 Q3 Q4 Decode Read register `f' Process Data No operation If skip: Q1 Q2 Q3 Q4 No operation No operation No operation No operation If skip and followed by 2-word instruction: Q1 Q2 Q3 Q4 No operation No operation No operation No operation No operation No operation No operation No operation Example: HERE NZERO ZERO Before Instruction PC After Instruction If CNT PC If CNT PC TSTFSZ : : CNT, 1 = Address (HERE) = = = 00h, Address (ZERO) 00h, Address (NZERO) 2010 Microchip Technology Inc. DS39770C-page 345 PIC18F85J90 FAMILY XORWF Exclusive OR W with f Syntax: XORWF Operands: 0 f 255 d [0,1] a [0,1] Operation: (W) .XOR. (f) dest Status Affected: N, Z Encoding: 0001 Description: f {,d {,a}} 10da ffff ffff Exclusive OR the contents of W with register `f'. If `d' is `0', the result is stored in W. If `d' is `1', the result is stored back in the register `f'. If `a' is `0', the Access Bank is selected. If `a' is `1', the BSR is used to select the GPR bank. If `a' is `0' and the extended instruction set is enabled, this instruction operates in Indexed Literal Offset Addressing mode whenever f 95 (5Fh). See Section 24.2.3 "Byte-Oriented and Bit-Oriented Instructions in Indexed Literal Offset Mode" for details. Words: 1 Cycles: 1 Q Cycle Activity: Q1 Q2 Q3 Q4 Decode Read register `f' Process Data Write to destination Example: XORWF Before Instruction REG = W = After Instruction REG = W = DS39770C-page 346 REG, 1, 0 AFh B5h 1Ah B5h 2010 Microchip Technology Inc. PIC18F85J90 FAMILY 24.2 Extended Instruction Set A summary of the instructions in the extended instruction set is provided in Table 24-3. Detailed descriptions are provided in Section 24.2.2 "Extended Instruction Set". The opcode field descriptions in Table 24-1 (page 306) apply to both the standard and extended PIC18 instruction sets. In addition to the standard 75 instructions of the PIC18 instruction set, the PIC18F85J90 family family of devices also provide an optional extension to the core CPU functionality. The added features include eight additional instructions that augment Indirect and Indexed Addressing operations and the implementation of Indexed Literal Offset Addressing for many of the standard PIC18 instructions. Note: The additional features of the extended instruction set are enabled by default on unprogrammed devices. Users must properly set or clear the XINST Configuration bit during programming to enable or disable these features. The instructions in the extended set can all be classified as literal operations, which either manipulate the File Select Registers, or use them for Indexed Addressing. Two of the instructions, ADDFSR and SUBFSR, each have an additional special instantiation for using FSR2. These versions (ADDULNK and SUBULNK) allow for automatic return after execution. 24.2.1 EXTENDED INSTRUCTION SYNTAX Most of the extended instructions use indexed arguments, using one of the File Select Registers and some offset to specify a source or destination register. When an argument for an instruction serves as part of Indexed Addressing, it is enclosed in square brackets ("[ ]"). This is done to indicate that the argument is used as an index or offset. The MPASMTM Assembler will flag an error if it determines that an index or offset value is not bracketed. The extended instructions are specifically implemented to optimize re-entrant program code (that is, code that is recursive or that uses a software stack) written in high-level languages, particularly C. Among other things, they allow users working in high-level languages to perform certain operations on data structures more efficiently. These include: When the extended instruction set is enabled, brackets are also used to indicate index arguments in byte-oriented and bit-oriented instructions. This is in addition to other changes in their syntax. For more details, see Section 24.2.3.1 "Extended Instruction Syntax with Standard PIC18 Commands". * Dynamic allocation and deallocation of software stack space when entering and leaving subroutines * Function Pointer invocation * Software Stack Pointer manipulation * Manipulation of variables located in a software stack TABLE 24-3: The instruction set extension and the Indexed Literal Offset Addressing mode were designed for optimizing applications written in C; the user may likely never use these instructions directly in assembler. The syntax for these commands is provided as a reference for users who may be reviewing code that has been generated by a compiler. Note: In the past, square brackets have been used to denote optional arguments in the PIC18 and earlier instruction sets. In this text and going forward, optional arguments are denoted by braces ("{ }"). EXTENSIONS TO THE PIC18 INSTRUCTION SET Mnemonic, Operands ADDFSR ADDULNK CALLW MOVSF f, k k MOVSS zs, zd PUSHL k SUBFSR SUBULNK f, k k zs, fd Description Add Literal to FSR Add Literal to FSR2 and return Call Subroutine Using WREG Move zs (source) to 1st word fd (destination) 2nd word Move zs (source) to 1st word zd (destination) 2nd word Store Literal at FSR2, Decrement FSR2 Subtract Literal from FSR Subtract Literal from FSR2 and Return 2010 Microchip Technology Inc. Cycles 1 2 2 2 16-Bit Instruction Word MSb LSb Status Affected None None None None 1 1110 1110 0000 1110 1111 1110 1111 1110 1000 1000 0000 1011 ffff 1011 xxxx 1010 ffkk 11kk 0001 0zzz ffff 1zzz xzzz kkkk kkkk kkkk 0100 zzzz ffff zzzz zzzz kkkk 1 2 1110 1110 1001 1001 ffkk 11kk kkkk None kkkk None 2 None None DS39770C-page 347 PIC18F85J90 FAMILY 24.2.2 EXTENDED INSTRUCTION SET ADDFSR Add Literal to FSR ADDULNK Syntax: ADDFSR f, k Syntax: ADDULNK k Operands: 0 k 63 f [ 0, 1, 2 ] Operands: 0 k 63 Operation: Operation: FSR(f) + k FSR(f) FSR2 + k FSR2, (TOS) PC Status Affected: None Status Affected: None Encoding: 1110 1000 ffkk kkkk Description: The 6-bit literal `k' is added to the contents of the FSR specified by `f'. Words: 1 Cycles: 1 Add Literal to FSR2 and Return Encoding: 1110 Description: Q2 Q3 Q4 Decode Read literal `k' Process Data Write to FSR Example: After Instruction FSR2 = 03FFh Words: 1 Cycles: 2 Q Cycle Activity: Q1 Q2 Q3 Q4 Decode Read literal `k' Process Data Write to FSR No Operation No Operation No Operation No Operation 0422h Example: Note: kkkk This may be thought of as a special case of the ADDFSR instruction, where f = 3 (binary `11'); it operates only on FSR2. ADDFSR 2, 23h Before Instruction FSR2 = 11kk The instruction takes two cycles to execute; a NOP is performed during the second cycle. Q Cycle Activity: Q1 1000 The 6-bit literal `k' is added to the contents of FSR2. A RETURN is then executed by loading the PC with the TOS. ADDULNK 23h Before Instruction FSR2 = PC = 03FFh 0100h After Instruction FSR2 = PC = 0422h (TOS) All PIC18 instructions may take an optional label argument preceding the instruction mnemonic for use in symbolic addressing. If a label is used, the instruction format then becomes: {label} instruction argument(s). DS39770C-page 348 2010 Microchip Technology Inc. PIC18F85J90 FAMILY CALLW Subroutine Call Using WREG MOVSF Move Indexed to f Syntax: CALLW Syntax: MOVSF [zs], fd Operands: None Operands: Operation: (PC + 2) TOS, (W) PCL, (PCLATH) PCH, (PCLATU) PCU 0 zs 127 0 fd 4095 Operation: ((FSR2) + zs) fd Status Affected: None Status Affected: None Encoding: 0000 Description 0000 0001 0100 First, the return address (PC + 2) is pushed onto the return stack. Next, the contents of W are written to PCL; the existing value is discarded. Then, the contents of PCLATH and PCLATU are latched into PCH and PCU, respectively. The second cycle is executed as a NOP instruction while the new next instruction is fetched. Encoding: 1st word (source) 2nd word (destin.) Description: Unlike CALL, there is no option to update W, STATUS or BSR. Words: 1 Cycles: 2 Q1 Q2 Q3 Q4 Read WREG Push PC to stack No operation No operation No operation No operation No operation Before Instruction PC = PCLATH = PCLATU = W = After Instruction PC = TOS = PCLATH = PCLATU = W = Words: 2 Cycles: 2 Q Cycle Activity: CALLW Decode address (HERE) 10h 00h 06h 001006h address (HERE + 2) 10h 00h 06h 2010 Microchip Technology Inc. zzzzs ffffd If the resultant source address points to an Indirect Addressing register, the value returned will be 00h. Decode HERE 0zzz ffff The contents of the source register are moved to destination register `fd'. The actual address of the source register is determined by adding the 7-bit literal offset `zs', in the first word, to the value of FSR2. The address of the destination register is specified by the 12-bit literal `fd' in the second word. Both addresses can be anywhere in the 4096-byte data space (000h to FFFh). Q1 Example: 1011 ffff The MOVSF instruction cannot use the PCL, TOSU, TOSH or TOSL as the destination register. Q Cycle Activity: Decode 1110 1111 Q2 Q3 Determine Determine source addr source addr No operation No operation No dummy read Example: MOVSF Before Instruction FSR2 Contents of 85h REG2 After Instruction FSR2 Contents of 85h REG2 Q4 Read source reg Write register `f' (dest) [05h], REG2 = 80h = = 33h 11h = 80h = = 33h 33h DS39770C-page 349 PIC18F85J90 FAMILY MOVSS Move Indexed to Indexed PUSHL Store Literal at FSR2, Decrement FSR2 Syntax: MOVSS [zs], [zd] Syntax: PUSHL k Operands: 0 zs 127 0 zd 127 Operands: 0k 255 Operation: k (FSR2), FSR2 - 1 FSR2 Status Affected: None Operation: ((FSR2) + zs) ((FSR2) + zd) Status Affected: None Encoding: 1st word (source) 2nd word (dest.) 1110 1111 Description 1011 xxxx 1zzz xzzz zzzzs zzzzd The contents of the source register are moved to the destination register. The addresses of the source and destination registers are determined by adding the 7-bit literal offsets, `zs' or `zd', respectively, to the value of FSR2. Both registers can be located anywhere in the 4096-byte data memory space (000h to FFFh). The MOVSS instruction cannot use the PCL, TOSU, TOSH or TOSL as the destination register. If the resultant source address points to an Indirect Addressing register, the value returned will be 00h. If the resultant destination address points to an Indirect Addressing register, the instruction will execute as a NOP. Words: 2 Cycles: 2 Q Cycle Activity: Q1 Decode Decode Q2 Q3 Determine Determine source addr source addr Determine dest addr Example: 1111 Description: 1010 kkkk kkkk The 8-bit literal `k' is written to the data memory address specified by FSR2. FSR2 is decremented by 1 after the operation. This instruction allows users to push values onto a software stack. Words: 1 Cycles: 1 Q Cycle Activity: Q1 Q2 Q3 Q4 Decode Read `k' Process data Write to destination Example: PUSHL 08h Before Instruction FSR2H:FSR2L Memory (01ECh) = = 01ECh 00h After Instruction FSR2H:FSR2L Memory (01ECh) = = 01EBh 08h Q4 Read source reg Write to dest reg MOVSS [05h], [06h] Before Instruction FSR2 Contents of 85h Contents of 86h After Instruction FSR2 Contents of 85h Contents of 86h DS39770C-page 350 Determine dest addr Encoding: = 80h = 33h = 11h = 80h = 33h = 33h 2010 Microchip Technology Inc. PIC18F85J90 FAMILY SUBFSR Subtract Literal from FSR SUBULNK Syntax: SUBFSR f, k Syntax: SUBULNK k Operands: 0 k 63 Operands: 0 k 63 f [ 0, 1, 2 ] Operation: Operation: FSRf - k FSRf FSR2 - k FSR2, (TOS) PC Status Affected: None Status Affected: None Encoding: 1110 1001 ffkk kkkk Description: The 6-bit literal `k' is subtracted from the contents of the FSR specified by `f'. Words: 1 Cycles: 1 Encoding: 1110 Description: Q1 Q2 Q3 Q4 Read register `f' Process Data Write to destination Example: Before Instruction FSR2 = After Instruction FSR2 = SUBFSR 2, 23h 1001 11kk kkkk The 6-bit literal `k' is subtracted from the contents of the FSR2. A RETURN is then executed by loading the PC with the TOS. The instruction takes two cycles to execute; a NOP is performed during the second cycle. Q Cycle Activity: Decode Subtract Literal from FSR2 and Return This may be thought of as a special case of the SUBFSR instruction, where f = 3 (binary `11'); it operates only on FSR2. Words: 1 Cycles: 2 Q Cycle Activity: 03FFh 03DCh Q1 Q2 Q3 Q4 Decode Read register `f' Process Data Write to destination No Operation No Operation No Operation No Operation Example: 2010 Microchip Technology Inc. SUBULNK 23h Before Instruction FSR2 = PC = 03FFh 0100h After Instruction FSR2 = PC = 03DCh (TOS) DS39770C-page 351 PIC18F85J90 FAMILY 24.2.3 Note: BYTE-ORIENTED AND BIT-ORIENTED INSTRUCTIONS IN INDEXED LITERAL OFFSET MODE Enabling the PIC18 instruction set extension may cause legacy applications to behave erratically or fail entirely. In addition to eight new commands in the extended set, enabling the extended instruction set also enables Indexed Literal Offset Addressing (Section 6.6.1 "Indexed Addressing with Literal Offset"). This has a significant impact on the way that many commands of the standard PIC18 instruction set are interpreted. When the extended set is disabled, addresses embedded in opcodes are treated as literal memory locations: either as a location in the Access Bank (a = 0) or in a GPR bank designated by the BSR (a = 1). When the extended instruction set is enabled and a = 0, however, a file register argument of 5Fh or less is interpreted as an offset from the pointer value in FSR2 and not as a literal address. For practical purposes, this means that all instructions that use the Access RAM bit as an argument - that is, all byte-oriented and bit-oriented instructions, or almost half of the core PIC18 instructions - may behave differently when the extended instruction set is enabled. When the content of FSR2 is 00h, the boundaries of the Access RAM are essentially remapped to their original values. This may be useful in creating backward-compatible code. If this technique is used, it may be necessary to save the value of FSR2 and restore it when moving back and forth between C and assembly routines in order to preserve the Stack Pointer. Users must also keep in mind the syntax requirements of the extended instruction set (see Section 24.2.3.1 "Extended Instruction Syntax with Standard PIC18 Commands"). Although the Indexed Literal Offset mode can be very useful for dynamic stack and pointer manipulation, it can also be very annoying if a simple arithmetic operation is carried out on the wrong register. Users who are accustomed to the PIC18 programming must keep in mind that, when the extended instruction set is enabled, register addresses of 5Fh or less are used for Indexed Literal Offset Addressing. Representative examples of typical byte-oriented and bit-oriented instructions in the Indexed Literal Offset mode are provided on the following page to show how execution is affected. The operand conditions shown in the examples are applicable to all instructions of these types. DS39770C-page 352 24.2.3.1 Extended Instruction Syntax with Standard PIC18 Commands When the extended instruction set is enabled, the file register argument, `f', in the standard byte-oriented and bit-oriented commands is replaced with the literal offset value, `k'. As already noted, this occurs only when `f' is less than or equal to 5Fh. When an offset value is used, it must be indicated by square brackets ("[ ]"). As with the extended instructions, the use of brackets indicates to the compiler that the value is to be interpreted as an index or an offset. Omitting the brackets, or using a value greater than 5Fh within the brackets, will generate an error in the MPASM Assembler. If the index argument is properly bracketed for Indexed Literal Offset Addressing, the Access RAM argument is never specified; it will automatically be assumed to be `0'. This is in contrast to standard operation (extended instruction set disabled), when `a' is set on the basis of the target address. Declaring the Access RAM bit in this mode will also generate an error in the MPASM Assembler. The destination argument, `d', functions as before. In the latest versions of the MPASM Assembler, language support for the extended instruction set must be explicitly invoked. This is done with either the command line option, /y, or the PE directive in the source listing. 24.2.4 CONSIDERATIONS WHEN ENABLING THE EXTENDED INSTRUCTION SET It is important to note that the extensions to the instruction set may not be beneficial to all users. In particular, users who are not writing code that uses a software stack may not benefit from using the extensions to the instruction set. Additionally, the Indexed Literal Offset Addressing mode may create issues with legacy applications written to the PIC18 assembler. This is because instructions in the legacy code may attempt to address registers in the Access Bank below 5Fh. Since these addresses are interpreted as literal offsets to FSR2 when the instruction set extension is enabled, the application may read or write to the wrong data addresses. When porting an application to the PIC18F85J90 family family, it is very important to consider the type of code. A large, re-entrant application that is written in C and would benefit from efficient compilation will do well when using the instruction set extensions. Legacy applications that heavily use the Access Bank will most likely not benefit from using the extended instruction set. 2010 Microchip Technology Inc. PIC18F85J90 FAMILY ADD W to Indexed (Indexed Literal Offset mode) BSF Bit Set Indexed (Indexed Literal Offset mode) Syntax: ADDWF Syntax: BSF [k], b Operands: 0 k 95 d [0,1] Operands: 0 f 95 0b7 Operation: (W) + ((FSR2) + k) dest Operation: 1 ((FSR2) + k)<b> Status Affected: N, OV, C, DC, Z Status Affected: None ADDWF Encoding: [k] {,d} 0010 Description: 01d0 kkkk kkkk The contents of W are added to the contents of the register indicated by FSR2, offset by the value `k'. If `d' is `0', the result is stored in W. If `d' is `1', the result is stored back in register `f'. Words: 1 Cycles: 1 Encoding: 1000 bbb0 kkkk kkkk Description: Bit `b' of the register indicated by FSR2, offset by the value `k', is set. Words: 1 Cycles: 1 Q Cycle Activity: Q1 Q2 Q3 Q4 Decode Read register `f' Process Data Write to destination Q Cycle Activity: Q1 Q2 Q3 Q4 Decode Read `k' Process Data Write to destination Example: ADDWF Before Instruction W OFST FSR2 Contents of 0A2Ch After Instruction W Contents of 0A2Ch [OFST] ,0 = = = 17h 2Ch 0A00h = 20h = 37h = 20h Example: BSF Before Instruction FLAG_OFST FSR2 Contents of 0A0Ah After Instruction Contents of 0A0Ah [FLAG_OFST], 7 = = 0Ah 0A00h = 55h = D5h SETF Set Indexed (Indexed Literal Offset mode) Syntax: SETF [k] Operands: 0 k 95 Operation: FFh ((FSR2) + k) Status Affected: None Encoding: 0110 1000 kkkk kkkk Description: The contents of the register indicated by FSR2, offset by `k', are set to FFh. Words: 1 Cycles: 1 Q Cycle Activity: Q1 Q2 Q3 Q4 Decode Read `k' Process Data Write register Example: SETF Before Instruction OFST FSR2 Contents of 0A2Ch After Instruction Contents of 0A2Ch 2010 Microchip Technology Inc. [OFST] = = 2Ch 0A00h = 00h = FFh DS39770C-page 353 PIC18F85J90 FAMILY 24.2.5 SPECIAL CONSIDERATIONS WITH MICROCHIP MPLAB(R) IDE TOOLS The latest versions of Microchip's software tools have been designed to fully support the extended instruction set for the PIC18F85J90 family family. This includes the MPLAB C18 C Compiler, MPASM assembly language and MPLAB Integrated Development Environment (IDE). When selecting a target device for software development, MPLAB IDE will automatically set default Configuration bits for that device. The default setting for the XINST Configuration bit is `1', enabling the extended instruction set and Indexed Literal Offset Addressing. For proper execution of applications developed to take advantage of the extended instruction set, XINST must be set during programming. DS39770C-page 354 To develop software for the extended instruction set, the user must enable support for the instructions and the Indexed Addressing mode in their language tool(s). Depending on the environment being used, this may be done in several ways: * A menu option or dialog box within the environment that allows the user to configure the language tool and its settings for the project * A command line option * A directive in the source code These options vary between different compilers, assemblers and development environments. Users are encouraged to review the documentation accompanying their development systems for the appropriate information. 2010 Microchip Technology Inc. PIC18F85J90 FAMILY 25.0 DEVELOPMENT SUPPORT The PIC(R) microcontrollers and dsPIC(R) digital signal controllers are supported with a full range of software and hardware development tools: * Integrated Development Environment - MPLAB(R) IDE Software * Compilers/Assemblers/Linkers - MPLAB C Compiler for Various Device Families - HI-TECH C for Various Device Families - MPASMTM Assembler - MPLINKTM Object Linker/ MPLIBTM Object Librarian - MPLAB Assembler/Linker/Librarian for Various Device Families * Simulators - MPLAB SIM Software Simulator * Emulators - MPLAB REAL ICETM In-Circuit Emulator * In-Circuit Debuggers - MPLAB ICD 3 - PICkitTM 3 Debug Express * Device Programmers - PICkitTM 2 Programmer - MPLAB PM3 Device Programmer * Low-Cost Demonstration/Development Boards, Evaluation Kits, and Starter Kits 25.1 MPLAB Integrated Development Environment Software The MPLAB IDE software brings an ease of software development previously unseen in the 8/16/32-bit microcontroller market. The MPLAB IDE is a Windows(R) operating system-based application that contains: * A single graphical interface to all debugging tools - Simulator - Programmer (sold separately) - In-Circuit Emulator (sold separately) - In-Circuit Debugger (sold separately) * A full-featured editor with color-coded context * A multiple project manager * Customizable data windows with direct edit of contents * High-level source code debugging * Mouse over variable inspection * Drag and drop variables from source to watch windows * Extensive on-line help * Integration of select third party tools, such as IAR C Compilers The MPLAB IDE allows you to: * Edit your source files (either C or assembly) * One-touch compile or assemble, and download to emulator and simulator tools (automatically updates all project information) * Debug using: - Source files (C or assembly) - Mixed C and assembly - Machine code MPLAB IDE supports multiple debugging tools in a single development paradigm, from the cost-effective simulators, through low-cost in-circuit debuggers, to full-featured emulators. This eliminates the learning curve when upgrading to tools with increased flexibility and power. 2010 Microchip Technology Inc. DS39770C-page 355 PIC18F85J90 FAMILY 25.2 MPLAB C Compilers for Various Device Families The MPLAB C Compiler code development systems are complete ANSI C compilers for Microchip's PIC18, PIC24 and PIC32 families of microcontrollers and the dsPIC30 and dsPIC33 families of digital signal controllers. These compilers provide powerful integration capabilities, superior code optimization and ease of use. For easy source level debugging, the compilers provide symbol information that is optimized to the MPLAB IDE debugger. 25.3 HI-TECH C for Various Device Families The HI-TECH C Compiler code development systems are complete ANSI C compilers for Microchip's PIC family of microcontrollers and the dsPIC family of digital signal controllers. These compilers provide powerful integration capabilities, omniscient code generation and ease of use. For easy source level debugging, the compilers provide symbol information that is optimized to the MPLAB IDE debugger. The compilers include a macro assembler, linker, preprocessor, and one-step driver, and can run on multiple platforms. 25.4 MPASM Assembler The MPASM Assembler is a full-featured, universal macro assembler for PIC10/12/16/18 MCUs. The MPASM Assembler generates relocatable object files for the MPLINK Object Linker, Intel(R) standard HEX files, MAP files to detail memory usage and symbol reference, absolute LST files that contain source lines and generated machine code and COFF files for debugging. The MPASM Assembler features include: 25.5 MPLINK Object Linker/ MPLIB Object Librarian The MPLINK Object Linker combines relocatable objects created by the MPASM Assembler and the MPLAB C18 C Compiler. It can link relocatable objects from precompiled libraries, using directives from a linker script. The MPLIB Object Librarian manages the creation and modification of library files of precompiled code. When a routine from a library is called from a source file, only the modules that contain that routine will be linked in with the application. This allows large libraries to be used efficiently in many different applications. The object linker/library features include: * Efficient linking of single libraries instead of many smaller files * Enhanced code maintainability by grouping related modules together * Flexible creation of libraries with easy module listing, replacement, deletion and extraction 25.6 MPLAB Assembler, Linker and Librarian for Various Device Families MPLAB Assembler produces relocatable machine code from symbolic assembly language for PIC24, PIC32 and dsPIC devices. MPLAB C Compiler uses the assembler to produce its object file. The assembler generates relocatable object files that can then be archived or linked with other relocatable object files and archives to create an executable file. Notable features of the assembler include: * * * * * * Support for the entire device instruction set Support for fixed-point and floating-point data Command line interface Rich directive set Flexible macro language MPLAB IDE compatibility * Integration into MPLAB IDE projects * User-defined macros to streamline assembly code * Conditional assembly for multi-purpose source files * Directives that allow complete control over the assembly process DS39770C-page 356 2010 Microchip Technology Inc. PIC18F85J90 FAMILY 25.7 MPLAB SIM Software Simulator The MPLAB SIM Software Simulator allows code development in a PC-hosted environment by simulating the PIC MCUs and dsPIC(R) DSCs on an instruction level. On any given instruction, the data areas can be examined or modified and stimuli can be applied from a comprehensive stimulus controller. Registers can be logged to files for further run-time analysis. The trace buffer and logic analyzer display extend the power of the simulator to record and track program execution, actions on I/O, most peripherals and internal registers. The MPLAB SIM Software Simulator fully supports symbolic debugging using the MPLAB C Compilers, and the MPASM and MPLAB Assemblers. The software simulator offers the flexibility to develop and debug code outside of the hardware laboratory environment, making it an excellent, economical software development tool. 25.8 MPLAB REAL ICE In-Circuit Emulator System MPLAB REAL ICE In-Circuit Emulator System is Microchip's next generation high-speed emulator for Microchip Flash DSC and MCU devices. It debugs and programs PIC(R) Flash MCUs and dsPIC(R) Flash DSCs with the easy-to-use, powerful graphical user interface of the MPLAB Integrated Development Environment (IDE), included with each kit. The emulator is connected to the design engineer's PC using a high-speed USB 2.0 interface and is connected to the target with either a connector compatible with incircuit debugger systems (RJ11) or with the new highspeed, noise tolerant, Low-Voltage Differential Signal (LVDS) interconnection (CAT5). The emulator is field upgradable through future firmware downloads in MPLAB IDE. In upcoming releases of MPLAB IDE, new devices will be supported, and new features will be added. MPLAB REAL ICE offers significant advantages over competitive emulators including low-cost, full-speed emulation, run-time variable watches, trace analysis, complex breakpoints, a ruggedized probe interface and long (up to three meters) interconnection cables. 2010 Microchip Technology Inc. 25.9 MPLAB ICD 3 In-Circuit Debugger System MPLAB ICD 3 In-Circuit Debugger System is Microchip's most cost effective high-speed hardware debugger/programmer for Microchip Flash Digital Signal Controller (DSC) and microcontroller (MCU) devices. It debugs and programs PIC(R) Flash microcontrollers and dsPIC(R) DSCs with the powerful, yet easyto-use graphical user interface of MPLAB Integrated Development Environment (IDE). The MPLAB ICD 3 In-Circuit Debugger probe is connected to the design engineer's PC using a high-speed USB 2.0 interface and is connected to the target with a connector compatible with the MPLAB ICD 2 or MPLAB REAL ICE systems (RJ-11). MPLAB ICD 3 supports all MPLAB ICD 2 headers. 25.10 PICkit 3 In-Circuit Debugger/ Programmer and PICkit 3 Debug Express The MPLAB PICkit 3 allows debugging and programming of PIC(R) and dsPIC(R) Flash microcontrollers at a most affordable price point using the powerful graphical user interface of the MPLAB Integrated Development Environment (IDE). The MPLAB PICkit 3 is connected to the design engineer's PC using a full speed USB interface and can be connected to the target via an Microchip debug (RJ-11) connector (compatible with MPLAB ICD 3 and MPLAB REAL ICE). The connector uses two device I/O pins and the reset line to implement in-circuit debugging and In-Circuit Serial ProgrammingTM. The PICkit 3 Debug Express include the PICkit 3, demo board and microcontroller, hookup cables and CDROM with user's guide, lessons, tutorial, compiler and MPLAB IDE software. DS39770C-page 357 PIC18F85J90 FAMILY 25.11 PICkit 2 Development Programmer/Debugger and PICkit 2 Debug Express 25.13 Demonstration/Development Boards, Evaluation Kits, and Starter Kits The PICkitTM 2 Development Programmer/Debugger is a low-cost development tool with an easy to use interface for programming and debugging Microchip's Flash families of microcontrollers. The full featured Windows(R) programming interface supports baseline (PIC10F, PIC12F5xx, PIC16F5xx), midrange (PIC12F6xx, PIC16F), PIC18F, PIC24, dsPIC30, dsPIC33, and PIC32 families of 8-bit, 16-bit, and 32-bit microcontrollers, and many Microchip Serial EEPROM products. With Microchip's powerful MPLAB Integrated Development Environment (IDE) the PICkitTM 2 enables in-circuit debugging on most PIC(R) microcontrollers. In-Circuit-Debugging runs, halts and single steps the program while the PIC microcontroller is embedded in the application. When halted at a breakpoint, the file registers can be examined and modified. A wide variety of demonstration, development and evaluation boards for various PIC MCUs and dsPIC DSCs allows quick application development on fully functional systems. Most boards include prototyping areas for adding custom circuitry and provide application firmware and source code for examination and modification. The PICkit 2 Debug Express include the PICkit 2, demo board and microcontroller, hookup cables and CDROM with user's guide, lessons, tutorial, compiler and MPLAB IDE software. 25.12 MPLAB PM3 Device Programmer The MPLAB PM3 Device Programmer is a universal, CE compliant device programmer with programmable voltage verification at VDDMIN and VDDMAX for maximum reliability. It features a large LCD display (128 x 64) for menus and error messages and a modular, detachable socket assembly to support various package types. The ICSPTM cable assembly is included as a standard item. In Stand-Alone mode, the MPLAB PM3 Device Programmer can read, verify and program PIC devices without a PC connection. It can also set code protection in this mode. The MPLAB PM3 connects to the host PC via an RS-232 or USB cable. The MPLAB PM3 has high-speed communications and optimized algorithms for quick programming of large memory devices and incorporates an MMC card for file storage and data applications. DS39770C-page 358 The boards support a variety of features, including LEDs, temperature sensors, switches, speakers, RS-232 interfaces, LCD displays, potentiometers and additional EEPROM memory. The demonstration and development boards can be used in teaching environments, for prototyping custom circuits and for learning about various microcontroller applications. In addition to the PICDEMTM and dsPICDEMTM demonstration/development board series of circuits, Microchip has a line of evaluation kits and demonstration software for analog filter design, KEELOQ(R) security ICs, CAN, IrDA(R), PowerSmart battery management, SEEVAL(R) evaluation system, Sigma-Delta ADC, flow rate sensing, plus many more. Also available are starter kits that contain everything needed to experience the specified device. This usually includes a single application and debug capability, all on one board. Check the Microchip web page (www.microchip.com) for the complete list of demonstration, development and evaluation kits. 2010 Microchip Technology Inc. PIC18F85J90 FAMILY 26.0 ELECTRICAL CHARACTERISTICS Absolute Maximum Ratings() Ambient temperature under bias.............................................................................................................-40C to +100C Storage temperature .............................................................................................................................. -65C to +150C Voltage on any digital only I/O pin or MCLR with respect to VSS (except VDD) ........................................... -0.3V to 5.6V Voltage on any combined digital and analog pin with respect to VSS (except VDD and MCLR)...... -0.3V to (VDD + 0.3V) Voltage on VDDCORE with respect to VSS ................................................................................................... -0.3V to 2.75V Voltage on VDD with respect to VSS ........................................................................................................... -0.3V to 3.6V Total power dissipation (Note 1) ...............................................................................................................................1.0W Maximum current out of VSS pin ...........................................................................................................................300 mA Maximum current into VDD pin ..............................................................................................................................250 mA Maximum output current sunk by PORTA<7:6> and any PORTB and PORTC I/O pins.........................................25 mA Maximum output current sunk by any PORTD, PORTE and PORTJ I/O pins ..........................................................8 mA Maximum output current sunk by PORTA<5:0> and any PORTF, PORTG and PORTH I/O pins ............................2 mA Maximum output current sourced by PORTA<7:6> and any PORTB and PORTC I/O pins ...................................25 mA Maximum output current sourced by any PORTD, PORTE and PORTJ I/O pins .....................................................8 mA Maximum output current sourced by PORTA<5:0> and any PORTF, PORTG and PORTH I/O pins .......................2 mA Maximum current sunk byall ports combined.......................................................................................................200 mA Note 1: Power dissipation is calculated as follows: Pdis = VDD x {IDD - IOH} + {(VDD - VOH) x IOH} + (VOL x IOL) NOTICE: Stresses above those listed under "Absolute Maximum Ratings" may cause permanent damage to the device. This is a stress rating only and functional operation of the device at those or any other conditions above those indicated in the operation listings of this specification is not implied. Exposure to maximum rating conditions for extended periods may affect device reliability. 2010 Microchip Technology Inc. DS39770C-page 359 PIC18F85J90 FAMILY FIGURE 26-1: PIC18F85J90 FAMILY VOLTAGE-FREQUENCY GRAPH, REGULATOR ENABLED (INDUSTRIAL)(1) 4.0V 3.6V Voltage (VDD) 3.5V 3.0V PIC18F6XJ90/8XJ90 2.5V 2.35V 2.0V 0 Note 1: 8 MHz Frequency 40 MHz When the on-chip regulator is enabled, its BOR circuit will automatically trigger a device Reset before VDD reaches a level at which full-speed operation is not possible. FIGURE 26-2: PIC18F85J90 FAMILY VOLTAGE-FREQUENCY GRAPH, REGULATOR DISABLED (INDUSTRIAL)(1,2) 3.00V Voltage (VDDCORE) 2.75V 2.7V 2.50V PIC18F6XJ90/8XJ90 2.25V 2.00V 8 MHz Note 1: 2: 2.35V Frequency 40 MHz For frequencies between 4 MHz and 40 MHz, FMAX = (51.42 MHz/V) * (VDDCORE - 2V) + 4 MHz. When the on-chip voltage regulator is disabled, VDD and VDDCORE must be maintained so that VDDCORE VDD 3.6V. DS39770C-page 360 2010 Microchip Technology Inc. PIC18F85J90 FAMILY 26.1 DC Characteristics: Supply Voltage PIC18F85J90 Family (Industrial) PIC18F85J90 Family (Industrial) Param Symbol No. D001 VDD Standard Operating Conditions (unless otherwise stated) Operating temperature -40C TA +85C for industrial Characteristic Supply Voltage D001B VDDCORE External Supply for Microcontroller Core Min Typ Max Units VDDCORE 2.0 -- -- 3.6 3.6 V V ENVREG tied to VSS ENVREG tied to VDD 2.0 -- 2.70 V ENVREG tied to VSS D001C AVDD Analog Supply Voltage VDD - 0.3 -- VDD + 0.3 V D001D AVSS Analog Ground Potential VSS - 0.3 -- VSS + 0.3 V D002 VDR RAM Data Retention Voltage(1) 1.5 -- -- V D003 VPOR VDD Start Voltage to Ensure Internal Power-on Reset signal -- -- 0.7 V D004 SVDD VDD Rise Rate to Ensure Internal Power-on Reset signal 0.05 -- -- D005 VBOR Brown-out Reset Voltage -- 1.9 -- Note 1: Conditions See Section 5.3 "Power-on Reset (POR)" for details V/ms See Section 5.3 "Power-on Reset (POR)" for details V This is the limit to which VDD can be lowered in Sleep mode, or during a device Reset, without losing RAM data. 2010 Microchip Technology Inc. DS39770C-page 361 PIC18F85J90 FAMILY 26.2 DC Characteristics: PIC18F85J90 Family (Industrial) Param No. Power-Down and Supply Current PIC18F85J90 Family (Industrial) Standard Operating Conditions (unless otherwise stated) Operating temperature -40C TA +85C for industrial Device Typ Max Units Conditions 0.2 0.9 A -40C 0.1 0.9 A +25C 0.3 3 A +60C 2.4 5 A +85C 0.5 0.9 A -40C 0.1 0.9 A +25C 0.4 3 A +60C 2.7 5 A +85C 2.7 6 A -40C 3.5 6 A +25C 4.1 8 A +60C 6.7 12 A +85C Power-Down Current (IPD)(1) All devices All devices All devices Note 1: 2: 3: 4: 5: 6: 7: VDD = 2.0V, VDDCORE = 2.0V (Sleep mode)(4) VDD = 2.5V, VDDCORE = 2.5V (Sleep mode)(4) VDD = 3.3V (Sleep mode)(5) The power-down current in Sleep mode does not depend on the oscillator type. Power-down current is measured with the part in Sleep mode, with all I/O pins in a high-impedance state and tied to VDD or VSS, and all features that add delta current disabled (such as WDT, Timer1 oscillator, BOR, etc.). The supply current is mainly a function of operating voltage, frequency and mode. Other factors, such as I/O pin loading and switching rate, oscillator type and circuit, internal code execution pattern and temperature, also have an impact on the current consumption. The test conditions for all IDD measurements in active operation mode are: OSC1 = external square wave, from rail-to-rail; all I/O pins tri-stated, pulled to VDD; MCLR = VDD; WDT enabled/disabled as specified. Standard, low-cost 32 kHz crystals have an operating temperature range of -10C to +70C. Extended temperature crystals are available at a much higher cost. Voltage regulator is disabled (ENVREG tied to VSS). Voltage regulator is enabled (ENVREG tied to VDD). Resistor ladder current is not included. Connecting an actual display will increase the current consumption depending on the size of the LCD. DS39770C-page 362 2010 Microchip Technology Inc. PIC18F85J90 FAMILY 26.2 DC Characteristics: PIC18F85J90 Family (Industrial) Param No. Power-Down and Supply Current PIC18F85J90 Family (Industrial) (Continued) Standard Operating Conditions (unless otherwise stated) Operating temperature -40C TA +85C for industrial Device Typ Max Units Conditions 6.5 16 A -40C 7 16 A +25C +85C Supply Current (IDD)(2) All devices All devices All devices All devices All devices All devices All devices All devices All devices Note 1: 2: 3: 4: 5: 6: 7: 9.5 20 A 10 18 A -40C 10.5 18 A +25C +85C 12.5 24 A 41 100 A -40C 52 100 A +25C 71 110 A +85C 359 750 A -40C 387 750 A +25C 407 840 A +85C 438 850 A -40C 470 850 A +25C 491 910 A +85C 486 900 A -40C 526 900 A +25C +85C 564 990 A 0.76 1.45 mA -40C 0.84 1.45 mA +25C 0.9 1.6 mA +85C 1.1 1.63 mA -40C 1.18 1.63 mA +25C 1.24 1.75 mA +85C 1.25 1.86 mA -40C 1.29 1.86 mA +25C 1.37 1.94 mA +85C VDD = 2.0V, VDDCORE = 2.0V(4) VDD = 2.5V, VDDCORE = 2.5V(4) FOSC = 31 kHz (INTRC_RUN mode, internal oscillator source) VDD = 3.3V(5) VDD = 2.0V, VDDCORE = 2.0V(4) VDD = 2.5V, VDDCORE = 2.5V(4) FOSC = 1 MHz (INTOSC_RUN mode, internal oscillator source) VDD = 3.3V(5) VDD = 2.0V, VDDCORE = 2.0V(4) VDD = 2.5V, VDDCORE = 2.5V(4) FOSC = 4 MHz (INTOSC_RUN mode, internal oscillator source) VDD = 3.3V(5) The power-down current in Sleep mode does not depend on the oscillator type. Power-down current is measured with the part in Sleep mode, with all I/O pins in a high-impedance state and tied to VDD or VSS, and all features that add delta current disabled (such as WDT, Timer1 oscillator, BOR, etc.). The supply current is mainly a function of operating voltage, frequency and mode. Other factors, such as I/O pin loading and switching rate, oscillator type and circuit, internal code execution pattern and temperature, also have an impact on the current consumption. The test conditions for all IDD measurements in active operation mode are: OSC1 = external square wave, from rail-to-rail; all I/O pins tri-stated, pulled to VDD; MCLR = VDD; WDT enabled/disabled as specified. Standard, low-cost 32 kHz crystals have an operating temperature range of -10C to +70C. Extended temperature crystals are available at a much higher cost. Voltage regulator is disabled (ENVREG tied to VSS). Voltage regulator is enabled (ENVREG tied to VDD). Resistor ladder current is not included. Connecting an actual display will increase the current consumption depending on the size of the LCD. 2010 Microchip Technology Inc. DS39770C-page 363 PIC18F85J90 FAMILY 26.2 DC Characteristics: PIC18F85J90 Family (Industrial) Param No. Power-Down and Supply Current PIC18F85J90 Family (Industrial) (Continued) Standard Operating Conditions (unless otherwise stated) Operating temperature -40C TA +85C for industrial Device Typ Max Units Conditions Supply Current (IDD)(2) All devices All devices All devices All devices All devices All devices All devices All devices All devices Note 1: 2: 3: 4: 5: 6: 7: 2.4 8 A -40C 2.5 8 A +25C 4.8 12 A +85C 3.2 9 A -40C 3.2 9 A +25C 6 14 A +85C 62 82 A -40C 42 82 A +25C 59 97 A +85C 251 570 A -40C 264 570 A +25C 272 590 A +85C 284 610 A -40C 284 610 A +25C 293 650 A +85C 295 710 A -40C 323 710 A +25C 392 790 A +85C 368 760 A -40C 362 760 A +25C 370 800 A +85C 400 850 A -40C 410 850 A +25C 418 900 A +85C 460 950 A -40C 462 950 A +25C 486 1000 A +85C VDD = 2.0V, VDDCORE = 2.0V(4) VDD = 2.5V, VDDCORE = 2.5V(4) FOSC = 31 kHz (INTRC_IDLE mode, internal oscillator source) VDD = 3.3V(5) VDD = 2.0V, VDDCORE = 2.0V(4) VDD = 2.5V, VDDCORE = 2.5V(4) FOSC = 1 MHz (INTOSC_IDLE mode, internal oscillator source) VDD = 3.3V(5) VDD = 2.0V, VDDCORE = 2.0V(4) VDD = 2.5V, VDDCORE = 2.5V(4) FOSC = 4 MHz (INTOSC_IDLE mode, internal oscillator source) VDD = 3.3V(5) The power-down current in Sleep mode does not depend on the oscillator type. Power-down current is measured with the part in Sleep mode, with all I/O pins in a high-impedance state and tied to VDD or VSS, and all features that add delta current disabled (such as WDT, Timer1 oscillator, BOR, etc.). The supply current is mainly a function of operating voltage, frequency and mode. Other factors, such as I/O pin loading and switching rate, oscillator type and circuit, internal code execution pattern and temperature, also have an impact on the current consumption. The test conditions for all IDD measurements in active operation mode are: OSC1 = external square wave, from rail-to-rail; all I/O pins tri-stated, pulled to VDD; MCLR = VDD; WDT enabled/disabled as specified. Standard, low-cost 32 kHz crystals have an operating temperature range of -10C to +70C. Extended temperature crystals are available at a much higher cost. Voltage regulator is disabled (ENVREG tied to VSS). Voltage regulator is enabled (ENVREG tied to VDD). Resistor ladder current is not included. Connecting an actual display will increase the current consumption depending on the size of the LCD. DS39770C-page 364 2010 Microchip Technology Inc. PIC18F85J90 FAMILY 26.2 DC Characteristics: PIC18F85J90 Family (Industrial) Param No. Power-Down and Supply Current PIC18F85J90 Family (Industrial) (Continued) Standard Operating Conditions (unless otherwise stated) Operating temperature -40C TA +85C for industrial Device Typ Max Units Conditions 165 490 A -40C 180 490 A +25C 200 490 A +85C 256 670 A -40C 260 670 A +25C 280 670 A +85C 460 850 A -40C 456 850 A +25C 482 850 A +85C Supply Current (IDD)(2) All devices All devices All devices All devices All devices All devices All devices All devices Note 1: 2: 3: 4: 5: 6: 7: 0.632 2.2 mA -40C 0.681 2.2 mA +25C 0.738 2.2 mA +85C 0.912 2.5 mA -40C 1.04 2.5 mA +25C 1.04 2.5 mA +85C 1.32 3.0 mA -40C 1.32 3.0 mA +25C 1.41 3.0 mA +85C 7.47 14 mA -40C 5.81 14 mA +25C 6.32 13 mA +85C 8.84 18 mA -40C 8.66 18 mA +25C 7.97 16 mA +85C VDD = 2.0V, VDDCORE = 2.0V(4) VDD = 2.5V, VDDCORE = 2.5V(4) FOSC = 1 MHZ (PRI_RUN mode, EC oscillator) VDD = 3.3V(5) VDD = 2.0V, VDDCORE = 2.0V(4) VDD = 2.5V, VDDCORE = 2.5V(4) FOSC = 4 MHz (PRI_RUN mode, EC oscillator) VDD = 3.3V(5) VDD = 2.5V, VDDCORE = 2.5V(4) VDD = 3.3V(5) FOSC = 40 MHZ (PRI_RUN mode, EC oscillator) The power-down current in Sleep mode does not depend on the oscillator type. Power-down current is measured with the part in Sleep mode, with all I/O pins in a high-impedance state and tied to VDD or VSS, and all features that add delta current disabled (such as WDT, Timer1 oscillator, BOR, etc.). The supply current is mainly a function of operating voltage, frequency and mode. Other factors, such as I/O pin loading and switching rate, oscillator type and circuit, internal code execution pattern and temperature, also have an impact on the current consumption. The test conditions for all IDD measurements in active operation mode are: OSC1 = external square wave, from rail-to-rail; all I/O pins tri-stated, pulled to VDD; MCLR = VDD; WDT enabled/disabled as specified. Standard, low-cost 32 kHz crystals have an operating temperature range of -10C to +70C. Extended temperature crystals are available at a much higher cost. Voltage regulator is disabled (ENVREG tied to VSS). Voltage regulator is enabled (ENVREG tied to VDD). Resistor ladder current is not included. Connecting an actual display will increase the current consumption depending on the size of the LCD. 2010 Microchip Technology Inc. DS39770C-page 365 PIC18F85J90 FAMILY 26.2 DC Characteristics: PIC18F85J90 Family (Industrial) Param No. Power-Down and Supply Current PIC18F85J90 Family (Industrial) (Continued) Standard Operating Conditions (unless otherwise stated) Operating temperature -40C TA +85C for industrial Device Typ Max Units 2.8 3.8 mA Conditions Supply Current (IDD)(2) All devices All devices All devices All devices All devices Note 1: 2: 3: 4: 5: 6: 7: -40C 3.02 3.8 mA +25C 3.01 4.5 mA +85C 4.5 5.4 mA -40C 4.8 5.6 mA +25C 4.54 5.6 mA +85C 5.72 6.7 mA -40C 5.55 6.5 mA +25C 5.3 6.5 mA +85C 7.4 8.5 mA -40C 7.23 8.5 mA +25C 6.55 7.5 mA +85C 9.74 11.6 mA -40C 9.43 11.6 mA +25C 8.89 10.5 mA +85C VDD = 2.0V, VDDCORE = 2.0V(4) FOSC = 4 MHZ, 16 MHz internal (PRI_RUN mode, HSPLL oscillator) VDD = 2.5V, VDDCORE = 2.5V(4) FOSC = 4 MHZ, 16 MHz internal (PRI_RUN mode, HSPLL oscillator) (5) VDD = 3.3V VDD = 2.5V, VDDCORE = 2.5V(4) VDD = 3.3V(5) FOSC = 4 MHZ, 16 MHz internal (PRI_RUN mode, HSPLL oscillator) FOSC = 10 MHZ, 40 MHz internal (PRI_RUN mode, HSPLL oscillator) FOSC = 10 MHZ, 40 MHz internal (PRI_RUN mode, HSPLL oscillator) The power-down current in Sleep mode does not depend on the oscillator type. Power-down current is measured with the part in Sleep mode, with all I/O pins in a high-impedance state and tied to VDD or VSS, and all features that add delta current disabled (such as WDT, Timer1 oscillator, BOR, etc.). The supply current is mainly a function of operating voltage, frequency and mode. Other factors, such as I/O pin loading and switching rate, oscillator type and circuit, internal code execution pattern and temperature, also have an impact on the current consumption. The test conditions for all IDD measurements in active operation mode are: OSC1 = external square wave, from rail-to-rail; all I/O pins tri-stated, pulled to VDD; MCLR = VDD; WDT enabled/disabled as specified. Standard, low-cost 32 kHz crystals have an operating temperature range of -10C to +70C. Extended temperature crystals are available at a much higher cost. Voltage regulator is disabled (ENVREG tied to VSS). Voltage regulator is enabled (ENVREG tied to VDD). Resistor ladder current is not included. Connecting an actual display will increase the current consumption depending on the size of the LCD. DS39770C-page 366 2010 Microchip Technology Inc. PIC18F85J90 FAMILY 26.2 DC Characteristics: PIC18F85J90 Family (Industrial) Param No. Power-Down and Supply Current PIC18F85J90 Family (Industrial) (Continued) Standard Operating Conditions (unless otherwise stated) Operating temperature -40C TA +85C for industrial Device Typ Max Units Conditions 50 120 A -40C 51 120 A +25C +85C Supply Current (IDD)(2) All devices All devices All devices All devices All devices All devices All devices All devices Note 1: 2: 3: 4: 5: 6: 7: 54 130 A 223 480 A -40C 133 300 A +25C +85C 110 270 A 307 550 A -40C 254 500 A +25C 194 460 A +85C 307 850 A -40C 200 850 A +25C 202 800 A +85C 483 950 A -40C 318 950 A +25C +85C 343 900 A 0.52 1.3 mA -40C 0.48 1.2 mA +25C 0.47 1.2 mA +85C 2.38 8 mA -40C 2.04 8 mA +25C 2.52 9 mA +85C 3.02 10 mA -40C 2.99 10 mA +25C 4.23 11 mA +85C VDD = 2.0V, VDDCORE = 2.0V(4) VDD = 2.5V, VDDCORE = 2.5V(4) FOSC = 1 MHz (PRI_IDLE mode, EC oscillator) VDD = 3.3V(5) VDD = 2.0V, VDDCORE = 2.0V(4) VDD = 2.5V, VDDCORE = 2.5V(4) FOSC = 4 MHz (PRI_IDLE mode, EC oscillator) VDD = 3.3V(5) VDD = 2.5V, VDDCORE = 2.5V(4) VDD = 3.3V(5) FOSC = 40 MHz (PRI_IDLE mode, EC oscillator) The power-down current in Sleep mode does not depend on the oscillator type. Power-down current is measured with the part in Sleep mode, with all I/O pins in a high-impedance state and tied to VDD or VSS, and all features that add delta current disabled (such as WDT, Timer1 oscillator, BOR, etc.). The supply current is mainly a function of operating voltage, frequency and mode. Other factors, such as I/O pin loading and switching rate, oscillator type and circuit, internal code execution pattern and temperature, also have an impact on the current consumption. The test conditions for all IDD measurements in active operation mode are: OSC1 = external square wave, from rail-to-rail; all I/O pins tri-stated, pulled to VDD; MCLR = VDD; WDT enabled/disabled as specified. Standard, low-cost 32 kHz crystals have an operating temperature range of -10C to +70C. Extended temperature crystals are available at a much higher cost. Voltage regulator is disabled (ENVREG tied to VSS). Voltage regulator is enabled (ENVREG tied to VDD). Resistor ladder current is not included. Connecting an actual display will increase the current consumption depending on the size of the LCD. 2010 Microchip Technology Inc. DS39770C-page 367 PIC18F85J90 FAMILY 26.2 DC Characteristics: PIC18F85J90 Family (Industrial) Param No. Power-Down and Supply Current PIC18F85J90 Family (Industrial) (Continued) Standard Operating Conditions (unless otherwise stated) Operating temperature -40C TA +85C for industrial Device Typ Max Units Conditions 10.5 22 A -40C 13.4 28 A +25C 17.6 40 A +85C 13.2 30 A -40C 16.2 35 A +25C +85C Supply Current (IDD)(2) All devices All devices All devices All devices All devices All devices Note 1: 2: 3: 4: 5: 6: 7: 20.7 50 A 39 120 A -40C 58 150 A +25C 75 190 A +85C 5.7 15 A -40C 8.9 20 A +25C 12.8 26 A +85C 6.6 17 A -40C 9.7 24 A +25C 13.7 30 A +85C 39 115 A -40C 52.8 145 A +25C 72.7 185 A +85C VDD = 2.0V, VDDCORE = 2.0V(4) VDD = 2.5V, VDDCORE = 2.5V(4) FOSC = 32 kHz(3) (SEC_RUN mode, Timer1 as clock) VDD = 3.3V(5) VDD = 2.0V, VDDCORE = 2.0V(4) VDD = 2.5V, VDDCORE = 2.5V(4) FOSC = 32 kHz(3) (SEC_IDLE mode, Timer1 as clock) VDD = 3.3V(5) The power-down current in Sleep mode does not depend on the oscillator type. Power-down current is measured with the part in Sleep mode, with all I/O pins in a high-impedance state and tied to VDD or VSS, and all features that add delta current disabled (such as WDT, Timer1 oscillator, BOR, etc.). The supply current is mainly a function of operating voltage, frequency and mode. Other factors, such as I/O pin loading and switching rate, oscillator type and circuit, internal code execution pattern and temperature, also have an impact on the current consumption. The test conditions for all IDD measurements in active operation mode are: OSC1 = external square wave, from rail-to-rail; all I/O pins tri-stated, pulled to VDD; MCLR = VDD; WDT enabled/disabled as specified. Standard, low-cost 32 kHz crystals have an operating temperature range of -10C to +70C. Extended temperature crystals are available at a much higher cost. Voltage regulator is disabled (ENVREG tied to VSS). Voltage regulator is enabled (ENVREG tied to VDD). Resistor ladder current is not included. Connecting an actual display will increase the current consumption depending on the size of the LCD. DS39770C-page 368 2010 Microchip Technology Inc. PIC18F85J90 FAMILY 26.2 DC Characteristics: PIC18F85J90 Family (Industrial) Param No. D022 (IWDT) Standard Operating Conditions (unless otherwise stated) Operating temperature -40C TA +85C for industrial Device D025 (IOSCB) D026 (IAD) Timer1 Oscillator A/D Converter Note 1: 2: 3: 4: 5: 6: 7: Typ Max Units Conditions Module Differential Currents (IWDT, ILCD, IOSCB, IAD) Watchdog Timer 1.6 4 A LCD Module D024 (ILCD) Power-Down and Supply Current PIC18F85J90 Family (Industrial) (Continued) -40C VDD = 2.0V, VDDCORE = 2.0V(4) 1.7 1.6 2.5 4 4 5 A A A +25C +85C -40C 2.5 2.3 3.8 2.6 2.4 2(6,7) 5 5 6 6 6 5 A A A A A A +25C +85C -40C +25C +85C +25C 2.7(6,7) 5 A +25C 3.5(6,7) 7 A +25C 16(7) 25 A +25C VDD = 2.0V 17(7) 25 A +25C VDD = 2.5V 24(7) 40 A +25C 6.6 7.9 11.5 7.2 8.1 11.9 7 9 11 12.5 12.5 18.5 12.5 12.5 18.5 12.5 12.5 18.5 A A A A A A A A A -40C +25C +85C -40C +25C +85C -40C +25C +85C 1 1.5 A -40C to +85C VDD = 2.0V, VDDCORE = 2.0V(4) 1 1.5 A -40C to +85C VDD = 2.5V, A/D on, not converting VDDCORE = 2.5V(4) 1 1.5 A -40C to +85C VDD = 2.5V, VDDCORE = 2.5V(4) VDD = 3.3V(5) VDD = 2.0V VDD = 2.5V VDD = 3.0V VDD = 3.0V Resistive Ladder CPEN = 0; CKSEL<1:0> = 00; CS<1:0> = 10; LP<3:0> = 0100 Charge Pump BIAS<2:0> = 111; CPEN = 1; CKSEL<1:0> = 11; CS<1:0> = 10 VDD = 2.0V, VDDCORE = 2.0V(4) 32 kHz on Timer1(3) VDD = 2.5V, VDDCORE = 2.5V(4) 32 kHz on Timer1(3) VDD = 3.3V(5) 32 kHz on Timer1(3) VDD = 3.3V(5) The power-down current in Sleep mode does not depend on the oscillator type. Power-down current is measured with the part in Sleep mode, with all I/O pins in a high-impedance state and tied to VDD or VSS, and all features that add delta current disabled (such as WDT, Timer1 oscillator, BOR, etc.). The supply current is mainly a function of operating voltage, frequency and mode. Other factors, such as I/O pin loading and switching rate, oscillator type and circuit, internal code execution pattern and temperature, also have an impact on the current consumption. The test conditions for all IDD measurements in active operation mode are: OSC1 = external square wave, from rail-to-rail; all I/O pins tri-stated, pulled to VDD; MCLR = VDD; WDT enabled/disabled as specified. Standard, low-cost 32 kHz crystals have an operating temperature range of -10C to +70C. Extended temperature crystals are available at a much higher cost. Voltage regulator is disabled (ENVREG tied to VSS). Voltage regulator is enabled (ENVREG tied to VDD). Resistor ladder current is not included. Connecting an actual display will increase the current consumption depending on the size of the LCD. 2010 Microchip Technology Inc. DS39770C-page 369 PIC18F85J90 FAMILY 26.3 DC Characteristics:PIC18F84J90 Family (Industrial) Standard Operating Conditions (unless otherwise stated) Operating temperature -40C TA +85C for industrial DC CHARACTERISTICS Param Symbol No. VIL Characteristic Min Max Units Conditions VSS 0.15 VDD V VDD < 3.3V -- 0.8 V 3.3V VDD 3.6V Input Low Voltage All I/O Ports: D030 with TTL Buffer D30A D031 with Schmitt Trigger Buffer D031A RC3 and RC4 D031B VSS 0.2 VDD V VSS 0.3 VDD V I2CTM enabled VSS 0.8 V SMBus enabled D032 MCLR VSS 0.2 VDD V D033 OSC1 VSS 0.3 VDD V HS, HSPLL modes D033A OSC1 VSS 0.2 VDD V EC, ECPLL modes T13CKI VSS 0.3 V 0.25 VDD + 0.8V VDD V VDD < 3.3V 3.3V VDD 3.6V D034 VIH Input High Voltage I/O Ports with non 5.5V Tolerance:(2) D040 with TTL Buffer D040A D041 with Schmitt Trigger Buffer D041A RC3 and RC4 D041B 2.0 VDD V 0.8 VDD VDD V 0.7 VDD VDD V I2CTM enabled 2.1 VDD V SMBus enabled, VDD < 3.3V I/O Ports with 5.5V Tolerance:(2) with TTL Buffer with Schmitt Trigger Buffer 0.25 VDD + 0.8V 5.5 V VDD < 3.3V 2.0 5.5 V 3.3V VDD 3.6V 0.8 VDD 5.5 V D042 MCLR 0.8 VDD VDD V D043 OSC1 0.7 VDD VDD V HS, HSPLL modes D043A OSC1 0.8 VDD VDD V EC, ECPLL modes 1.6 VDD V I/O Ports with non 5.5V tolerance:(2) -- 200 nA VSS VPIN VDD, Pin at high-impedance I/O Ports with 5.5V tolerance:(2) -- 200 nA VSS VPIN 5.5V, Pin at high-impedance MCLR -- 1 A VSS VPIN VDD OSC1 -- 1 A VSS VPIN VDD 30 400 A VDD = 3.3V, VPIN = VSS D044 T13CKI IIL D060 D061 D063 D070 Note 1: 2: Input Leakage Current(1) IPU Weak Pull-up Current IPURB PORTB Weak Pull-up Current Negative current is defined as current sourced by the pin. Refer to Table 10-1 for the pins that have corresponding tolerance limits. DS39770C-page 370 2010 Microchip Technology Inc. PIC18F85J90 FAMILY 26.3 DC Characteristics:PIC18F84J90 Family (Industrial) (Continued) Standard Operating Conditions (unless otherwise stated) Operating temperature -40C TA +85C for industrial DC CHARACTERISTICS Param Symbol No. VOL D080 Characteristic Min Max Units Conditions PORTA, PORTF, PORTG, PORTH -- 0.4 V IOL = 3.4 mA, VDD = 3.3V, -40C to +85C PORTD, PORTE, PORTJ -- 0.4 V IOL = 3.4 mA, VDD = 3.3V, -40C to +85C PORTB, PORTC -- 0.4 V IOL = 8.5 mA, VDD = 3.3V, -40C to +85C OSC2/CLKO (EC, ECPLL modes) -- 0.4 V IOL = 1.6 mA, VDD = 3.3V, -40C to +85C PORTA, PORTF, PORTG, PORTH 2.4 -- V IOH = -2 mA, VDD = 3.3V, -40C to +85C PORTD, PORTE, PORTJ 2.4 -- V IOH = -2 mA, VDD = 3.3V, -40C to +85C PORTB, PORTC 2.4 -- V IOH = -6 mA, VDD = 3.3V, -40C to +85C 2.4 -- V IOH = -1 mA, VDD = 3.3V, -40C to +85C Output Low Voltage I/O Ports: D083 VOH D090 Output High Voltage(1) I/O Ports: D092 OSC2/CLKO (INTOSC, EC, ECPLL modes) V Capacitive Loading Specs on Output Pins D100 COSC2 OSC2 Pin -- 15 pF In HS mode when external clock is used to drive OSC1 D101 CIO All I/O Pins and OSC2 -- 50 pF To meet the AC Timing Specifications D102 CB SCL, SDA -- 400 pF I2CTM Specification Note 1: 2: Negative current is defined as current sourced by the pin. Refer to Table 10-1 for the pins that have corresponding tolerance limits. 2010 Microchip Technology Inc. DS39770C-page 371 PIC18F85J90 FAMILY TABLE 26-1: MEMORY PROGRAMMING REQUIREMENTS Standard Operating Conditions (unless otherwise stated) Operating temperature -40C TA +85C for industrial DC CHARACTERISTICS Param No. Sym Characteristic Min Typ Max Units Conditions Program Flash Memory D130 EP Cell Endurance 100 1K -- E/W -40C to +85C D131 VPR VDD for Read VMIN -- 3.6 V VMIN = Minimum operating voltage D132 VPEW Voltage for Self-Timed Erase or Write: VDD 2.35 -- 3.6 V ENVREG tied to VDD VDDCORE ENVREG tied to VSS 2.25 -- 2.7 V D133A TIW Self-Timed Write Cycle Time -- 2.8 -- ms D133B TIE Self-Timed Block Erased Cycle Time -- 33 -- ms D134 TRETD Characteristic Retention 20 -- -- Year Provided no other specifications are violated D135 IDDP Supply Current during Programming -- 3 7 mA D1xxx TWE Writes per Erase Cycle -- -- 1 Per one physical word address Data in "Typ" column is at 3.3V, 25C unless otherwise stated. These parameters are for design guidance only and are not tested. TABLE 26-2: COMPARATOR SPECIFICATIONS Operating Conditions: 3.0V VDD 3.6V, -40C TA +85C (unless otherwise stated) Param No. Sym Characteristics Min Typ Max Units D300 VIOFF Input Offset Voltage -- 5.0 25 mV D301 VICM Input Common Mode Voltage 0 -- AVDD - 1.5 V D302 CMRR Common Mode Rejection Ratio 55 -- -- dB D303 TRESP Response Time(1) -- 150 400 ns D304 TMC2OV Comparator Mode Change to Output Valid* -- -- 10 s VIRV Internal Reference Voltage -- 1.2 -- V D305 Note 1: Comments Response time measured with one comparator input at (AVDD - 1.5)/2, while the other input transitions from VSS to VDD. DS39770C-page 372 2010 Microchip Technology Inc. PIC18F85J90 FAMILY TABLE 26-3: VOLTAGE REFERENCE SPECIFICATIONS Operating Conditions: 3.0V VDD 3.6V, -40C TA +85C (unless otherwise stated) Param No. Sym Characteristics Min Typ Max Units D310 VRES Resolution VDD/24 -- VDD/32 LSb D311 VRAA Absolute Accuracy -- -- 1/2 LSb D312 VRUR Unit Resistor Value (R) -- 2k -- D313 TSET Settling Time(1) -- -- 10 s Note 1: Comments Settling time measured while CVRR = 1 and CVR<3:0> transitions from `0000' to `1111'. TABLE 26-4: INTERNAL VOLTAGE REGULATOR SPECIFICATIONS Operating Conditions: -40C TA +85C (unless otherwise stated) Param No. Sym Characteristics VRGOUT Regulator Output Voltage CEFC TABLE 26-5: External Filter Capacitor Value Min Typ Max Units -- 2.5 -- V 4.7 10 -- F Comments Capacitor must be low series resistance (<5 Ohms) INTERNAL LCD VOLTAGE REGULATOR SPECIFICATIONS Operating Conditions: 2.0V VDD 3.6V, -40C TA +85C (unless otherwise stated) Param No. Sym Characteristics CFLY Fly Back Capacitor VBIAS VPK-PK between LCDBIAS0 and LCDBIAS3 2010 Microchip Technology Inc. Min Typ Max Units Comments 0.47 4.7 -- F Capacitor must be low-ESR -- 3.40 3.6 V BIAS<2:0> = 111 -- 3.27 -- V BIAS<2:0> = 110 -- 3.14 -- V BIAS<2:0> = 101 -- 3.01 -- V BIAS<2:0> = 100 -- 2.88 -- V BIAS<2:0> = 011 -- 2.75 -- V BIAS<2:0> = 010 -- 2.62 -- V BIAS<2:0> = 001 -- 2.49 -- V BIAS<2:0> = 000 DS39770C-page 373 PIC18F85J90 FAMILY 26.4 26.4.1 AC (Timing) Characteristics TIMING PARAMETER SYMBOLOGY The timing parameter symbols have been created following one of the following formats: 1. TppS2ppS 2. TppS T F Frequency Lowercase letters (pp) and their meanings: pp cc CCP1 ck CLKO cs CS di SDI do SDO dt Data in io I/O port mc MCLR Uppercase letters and their meanings: S F Fall H High I Invalid (High-Impedance) L Low I2C only AA output access BUF Bus free TCC:ST (I2C specifications only) CC HD Hold ST DAT DATA input hold STA Start condition DS39770C-page 374 3. TCC:ST 4. Ts (I2C specifications only) (I2C specifications only) T Time osc rd rw sc ss t0 t1 wr OSC1 RD RD or WR SCK SS T0CKI T13CKI WR P R V Z Period Rise Valid High-Impedance High Low High Low SU Setup STO Stop condition 2010 Microchip Technology Inc. PIC18F85J90 FAMILY 26.4.2 TIMING CONDITIONS The temperature and voltages specified in Table 26-6 apply to all timing specifications unless otherwise noted. Figure 26-3 specifies the load conditions for the timing specifications. TABLE 26-6: TEMPERATURE AND VOLTAGE SPECIFICATIONS - AC Standard Operating Conditions (unless otherwise stated) Operating temperature -40C TA +85C for industrial Operating voltage VDD range as described in Section 26.1 and Section 26.3. AC CHARACTERISTICS FIGURE 26-3: LOAD CONDITIONS FOR DEVICE TIMING SPECIFICATIONS Load Condition 1 Load Condition 2 VDD/2 RL CL Pin CL Pin VSS VSS RL = 464 CL = 50 pF for all pins except OSC2/CLKO/RA6 and including D and E outputs as ports CL = 15 pF for OSC2/CLKO/RA6 2010 Microchip Technology Inc. DS39770C-page 375 PIC18F85J90 FAMILY 26.4.3 TIMING DIAGRAMS AND SPECIFICATIONS FIGURE 26-4: EXTERNAL CLOCK TIMING Q4 Q1 Q2 Q3 Q4 Q1 OSC1 1 3 4 3 4 2 CLKO TABLE 26-7: Param. No. 1A EXTERNAL CLOCK TIMING REQUIREMENTS Symbol FOSC Characteristic Min Max Units External CLKI Frequency(1) DC 40 MHz ECPLL Oscillator mode (1) DC 40 MHz HSPLL Oscillator mode External CLKI Period(1) 25 -- ns Oscillator Frequency 1 TOSC Conditions (1) EC Oscillator mode Oscillator Period 25 250 ns HS Oscillator mode 2 TCY Instruction Cycle Time(1) 100 -- ns TCY = 4/FOSC, Industrial 3 TOSL, TOSH External Clock in (OSC1) High or Low Time 10 -- ns EC Oscillator mode 4 TOSR, TOSF External Clock in (OSC1) Rise or Fall Time -- 7.5 ns EC Oscillator mode Note 1: Instruction cycle period (TCY) equals four times the input oscillator time base period for all configurations except PLL. All specified values are based on characterization data for that particular oscillator type under standard operating conditions with the device executing code. Exceeding these specified limits may result in an unstable oscillator operation and/or higher than expected current consumption. All devices are tested to operate at "min." values with an external clock applied to the OSC1/CLKI pin. When an external clock input is used, the "max." cycle time limit is "DC" (no clock) for all devices. DS39770C-page 376 2010 Microchip Technology Inc. PIC18F85J90 FAMILY TABLE 26-8: Param No. PLL CLOCK TIMING SPECIFICATIONS (VDD = 2.15V TO 3.6V) Sym Characteristic Min Typ Max 4 16 -- -- 10 40 Units F10 F11 FOSC Oscillator Frequency Range FSYS On-Chip VCO System Frequency F12 trc PLL Start-up Time (Lock Time) -- -- 2 ms CLK CLKO Stability (Jitter) -2 -- +2 % F13 Conditions MHz HS mode only MHz HS mode only Data in "Typ" column is at 3.3V, 25C, unless otherwise stated. These parameters are for design guidance only and are not tested. TABLE 26-9: INTERNAL RC ACCURACY (INTOSC AND INTRC SOURCES) PIC18F85J90 Family (Industrial) Param No. Device Standard Operating Conditions (unless otherwise stated) Operating temperature -40C TA +85C for industrial Min Typ Max Units Conditions INTOSC Accuracy @ Freq = 8 MHz, 4 MHz, 2 MHz, 1 MHz, 500 kHz, 250 kHz, 125 kHz, 31 kHz(1) All Devices -2 1 2 % +25C VDD = 2.7-3.3V -5 -- 5 % -10C to +85C VDD = 2.0-3.3V -10 1 10 % -40C to +85C VDD = 2.0-3.3V -- 35.938 kHz -40C to +85C VDD = 2.0-3.3V INTRC Accuracy @ Freq = 31 kHz(1) All Devices Note 1: 26.562 The accuracy specification of the 31 kHz clock is determined by which source is providing it at a given time. When INTSRC (OSCTUNE<7>) is `1', use the INTOSC accuracy specification. When INTSRC is `0', use the INTRC accuracy specification. 2010 Microchip Technology Inc. DS39770C-page 377 PIC18F85J90 FAMILY FIGURE 26-5: CLKO AND I/O TIMING Q1 Q4 Q2 Q3 OSC1 11 10 CLKO 13 14 19 12 18 16 I/O pin (Input) 15 17 I/O pin (Output) New Value Old Value 20, 21 Note: Refer to Figure 26-3 for load conditions. TABLE 26-10: CLKO AND I/O TIMING REQUIREMENTS Param No. Symbol Characteristic Min Typ Max -- 75 200 Units Conditions 10 TOSH2CKL OSC1 to CLKO 11 TOSH2CKH OSC1 to CLKO -- 75 200 ns (Note 1) 12 TCKR CLKO Rise Time -- 15 30 ns (Note 1) 13 TCKF CLKO Fall Time -- 15 30 ns (Note 1) 14 TCKL2IOV CLKO to Port Out Valid -- -- 0.5 TCY + 20 ns 15 TIOV2CKH Port In Valid before CLKO 16 TCKH2IOI 17 TOSH2IOV OSC1 (Q1 cycle) to Port Out Valid 18 TOSH2IOI 19 Port In Hold after CLKO ns 0.25 TCY + 25 -- -- ns 0 -- -- ns -- 50 150 ns 100 -- -- ns TIOV2OSH Port Input Valid to OSC1 (I/O in setup time) 0 -- -- ns 20 TIOR Port Output Rise Time -- -- 6 ns 21 TIOF Port Output Fall Time -- -- 5 ns 22 TINP INTx Pin High or Low Time TCY -- -- ns 23 TRBP RB<7:4> Change INTx High or Low Time TCY -- -- ns OSC1 (Q2 cycle) to Port Input Invalid (I/O in hold time) (Note 1) These parameters are asynchronous events not related to any internal clock edges. Note 1: Measurements are taken in EC mode, where CLKO output is 4 x TOSC. DS39770C-page 378 2010 Microchip Technology Inc. PIC18F85J90 FAMILY FIGURE 26-6: RESET, WATCHDOG TIMER, OSCILLATOR START-UP TIMER AND POWER-UP TIMER TIMING VDD MCLR 30 Internal POR PWRT Time-out 33 32 Oscillator Time-out Internal Reset Watchdog Timer Reset 31 34 34 I/O pins Note: Refer to Figure 26-3 for load conditions. TABLE 26-11: RESET, WATCHDOG TIMER, OSCILLATOR START-UP TIMER, POWER-UP TIMER AND BROWN-OUT RESET REQUIREMENTS Param. Symbol No. Characteristic Min Typ Max 2 TCY 10 TCY -- Units 30 TMCL MCLR Pulse Width (low) 31 TWDT Watchdog Timer Time-out Period (no postscaler) 3.4 4.0 4.6 ms 32 TOST Oscillation Start-up Timer Period 1024 TOSC -- 1024 TOSC -- 33 TPWRT Power-up Timer Period 45.8 65.5 85.2 ms 34 TIOZ I/O High-Impedance from MCLR Low or Watchdog Timer Reset -- 2 -- s 38 TCSD CPU Start-up Time -- 10 -- s -- 200 -- s -- 1 -- s 39 Note 1: TIOBST Time for INTOSC to Stabilize Conditions (Note 1) TOSC = OSC1 period Voltage regulator enabled and put to Sleep To ensure device Reset, MCLR must be low for at least 2 TCY or 400 s, whichever is lower. 2010 Microchip Technology Inc. DS39770C-page 379 PIC18F85J90 FAMILY FIGURE 26-7: TIMER0 AND TIMER1 EXTERNAL CLOCK TIMINGS T0CKI 41 40 42 T1OSO/T13CKI 46 45 47 48 TMR0 or TMR1 Note: Refer to Figure 26-3 for load conditions. TABLE 26-12: TIMER0 AND TIMER1 EXTERNAL CLOCK REQUIREMENTS Param No. Symbol Characteristic 40 TT0H T0CKI High Pulse Width No prescaler 41 TT0L T0CKI Low Pulse Width No prescaler 42 TT0P T0CKI Period No prescaler With prescaler With prescaler With prescaler 45 46 47 TT1H TT1L T13CKI High Synchronous, no prescaler Time Synchronous, with prescaler Units 0.5 TCY + 20 -- ns 10 -- ns 0.5 TCY + 20 -- ns 10 -- ns TCY + 10 -- ns Greater of: 20 ns or (TCY + 40)/N -- ns 0.5 TCY + 20 -- ns 10 -- ns Asynchronous 30 -- ns 0.5 TCY + 5 -- ns 10 -- ns Asynchronous 30 -- ns Greater of: 20 ns or (TCY + 40)/N -- ns TT1P T13CKI Input Synchronous Period FT 1 T13CKI Oscillator Input Frequency Range TCKE2TMRI Delay from External T13CKI Clock Edge to Timer Increment DS39770C-page 380 Max T13CKI Low Synchronous, no prescaler Time Synchronous, with prescaler Asynchronous 48 Min 60 -- ns DC 50 kHz 2 TOSC 7 TOSC -- Conditions N = prescale value (1, 2, 4,..., 256) N = prescale value (1, 2, 4, 8) 2010 Microchip Technology Inc. PIC18F85J90 FAMILY FIGURE 26-8: CAPTURE/COMPARE/PWM TIMINGS (CCP1, CCP2 MODULES) CCPx (Capture Mode) 50 51 52 CCPx (Compare or PWM Mode) 53 Note: 54 Refer to Figure 26-3 for load conditions. TABLE 26-13: CAPTURE/COMPARE/PWM REQUIREMENTS (CCP1, CCP2 MODULES) Param Symbol No. 50 51 TCCL TCCH Characteristic Min Max Units CCPx Input Low No prescaler Time With prescaler 0.5 TCY + 20 -- ns 10 -- ns CCPx Input High Time 0.5 TCY + 20 -- ns 10 -- ns 3 TCY + 40 N -- ns No prescaler With prescaler TCCP CCPx Input Period 53 TCCR CCPx Output Fall Time -- 25 ns 54 TCCF CCPx Output Fall Time -- 25 ns 52 2010 Microchip Technology Inc. Conditions N = prescale value (1, 4 or 16) DS39770C-page 381 PIC18F85J90 FAMILY FIGURE 26-9: EXAMPLE SPI MASTER MODE TIMING (CKE = 0) 70 SCK (CKP = 0) 71 72 78 79 79 78 SCK (CKP = 1) 80 bit 6 - - - - - - 1 MSb SDO LSb 75, 76 SDI MSb In bit 6 - - - - 1 LSb In 74 73 Note: Refer to Figure 26-3 for load conditions. TABLE 26-14: EXAMPLE SPI MODE REQUIREMENTS (MASTER MODE, CKE = 0) Param No. Symbol Characteristic Min Max Units 73 TDIV2SCH, TDIV2SCL Setup Time of SDI Data Input to SCK Edge 73A TB2B Last Clock Edge of Byte 1 to the 1st Clock Edge of Byte 2 74 TSCH2DIL, TSCL2DIL Hold Time of SDI Data Input to SCK Edge 75 TDOR SDO Data Output Rise Time -- 25 ns 76 TDOF SDO Data Output Fall Time -- 25 ns 78 TSCR SCK Output Rise Time (Master mode) -- 25 ns 79 TSCF SCK Output Fall Time (Master mode) -- 25 ns 80 TSCH2DOV, SDO Data Output Valid after SCK Edge TSCL2DOV -- 50 ns Note 1: 20 -- ns 1.5 TCY + 40 -- ns 40 -- ns Conditions (Note 1) Only if Parameter #71A and #72A are used. DS39770C-page 382 2010 Microchip Technology Inc. PIC18F85J90 FAMILY FIGURE 26-10: EXAMPLE SPI MASTER MODE TIMING (CKE = 1) 81 SCK (CKP = 0) 71 72 79 73 SCK (CKP = 1) 80 78 MSb SDO bit 6 - - - - - - 1 LSb bit 6 - - - - 1 LSb In 75, 76 SDI MSb In 74 Note: Refer to Figure 26-3 for load conditions. TABLE 26-15: EXAMPLE SPI MODE REQUIREMENTS (MASTER MODE, CKE = 1) Param. No. Symbol Characteristic Min Max Units 73 TDIV2SCH, TDIV2SCL Setup Time of SDI Data Input to SCK Edge 73A TB2B Last Clock Edge of Byte 1 to the 1st Clock Edge of Byte 2 74 TSCH2DIL, TSCL2DIL Hold Time of SDI Data Input to SCK Edge 75 TDOR SDO Data Output Rise Time -- 25 ns 76 TDOF SDO Data Output Fall Time -- 25 ns 78 TSCR SCK Output Rise Time (Master mode) -- 25 ns 79 TSCF SCK Output Fall Time (Master mode) -- 25 ns 80 TSCH2DOV, SDO Data Output Valid after SCK Edge TSCL2DOV -- 50 ns 81 TDOV2SCH, SDO Data Output Setup to SCK Edge TDOV2SCL TCY -- ns Note 1: 20 -- ns 1.5 TCY + 40 -- ns 40 -- ns Conditions (Note 1) Only if Parameter #71A and #72A are used. 2010 Microchip Technology Inc. DS39770C-page 383 PIC18F85J90 FAMILY FIGURE 26-11: EXAMPLE SPI SLAVE MODE TIMING (CKE = 0) SS 70 SCK (CKP = 0) 83 71 72 78 79 79 78 SCK (CKP = 1) 80 MSb SDO bit 6 - - - - - - 1 LSb 75, 76 MSb In SDI 77 bit 6 - - - - 1 LSb In 74 73 Note: Refer to Figure 26-3 for load conditions. TABLE 26-16: EXAMPLE SPI MODE REQUIREMENTS (SLAVE MODE TIMING, CKE = 0) Param No. Symbol Characteristic Min Max Units Conditions 70 TSSL2SCH, SS to SCK or SCK Input TSSL2SCL 3 TCY -- ns 70A TSSL2WB SS to Write to SSPBUF 3 TCY -- ns 71 TSCH SCK Input High Time (Slave mode) 71A 72 TSCL SCK Input Low Time (Slave mode) 72A Continuous 1.25 TCY + 30 -- ns Single byte 40 -- ns Continuous 1.25 TCY + 30 -- ns Single byte 40 -- ns 20 -- ns -- ns -- ns 73 TDIV2SCH, Setup Time of SDI Data Input to SCK Edge TDIV2SCL 73A TB2B 74 TSCH2DIL, Hold Time of SDI Data Input to SCK Edge TSCL2DIL 75 TDOR SDO Data Output Rise Time -- 25 ns 76 TDOF SDO Data Output Fall Time -- 25 ns 77 TSSH2DOZ SS to SDO Output High-Impedance 10 50 ns Last Clock Edge of Byte 1 to the First Clock Edge of Byte 2 1.5 TCY + 40 40 78 TSCR SCK Output Rise Time (Master mode) -- 25 ns 79 TSCF SCK Output Fall Time (Master mode) -- 25 ns 80 TSCH2DOV, SDO Data Output Valid after SCK Edge TSCL2DOV -- 50 ns 83 TSCH2SSH, SS after SCK Edge TSCL2SSH 1.5 TCY + 40 -- ns Note 1: 2: (Note 1) (Note 1) (Note 2) Requires the use of Parameter #73A. Only if Parameter #71A and #72A are used. DS39770C-page 384 2010 Microchip Technology Inc. PIC18F85J90 FAMILY FIGURE 26-12: EXAMPLE SPI SLAVE MODE TIMING (CKE = 1) 82 SS SCK (CKP = 0) 70 83 71 72 SCK (CKP = 1) 80 MSb SDO bit 6 - - - - - - 1 LSb 75, 76 SDI MSb In 77 bit 6 - - - - 1 LSb In 74 Note: Refer to Figure 26-3 for load conditions. TABLE 26-17: EXAMPLE SPI SLAVE MODE REQUIREMENTS (CKE = 1) Param No. Symbol Characteristic Min Max Units Conditions 70 TSSL2SCH, SS to SCK or SCK Input TSSL2SCL 3 TCY -- ns 70A TSSL2WB SS to Write to SSPBUF 3 TCY -- ns 71 TSCH SCK Input High Time (Slave mode) Continuous 1.25 TCY + 30 -- ns Single byte 40 -- ns SCK Input Low Time (Slave mode) Continuous 1.25 TCY + 30 -- ns Single byte 40 -- ns (Note 1) -- ns (Note 2) -- ns 71A 72 TSCL 72A 73A TB2B 74 TSCH2DIL, Hold Time of SDI Data Input to SCK Edge TSCL2DIL 75 TDOR SDO Data Output Rise Time -- 25 ns 76 TDOF SDO Data Output Fall Time -- 25 ns 77 TSSH2DOZ SS to SDO Output High-Impedance 10 50 ns 78 TSCR SCK Output Rise Time (Master mode) -- 25 ns 79 TSCF SCK Output Fall Time (Master mode) -- 25 ns 80 TSCH2DOV, SDO Data Output Valid after SCK Edge TSCL2DOV -- 50 ns 82 TSSL2DOV SDO Data Output Valid after SS Edge -- 50 ns 83 TSCH2SSH, SS after SCK Edge TSCL2SSH 1.5 TCY + 40 -- ns Note 1: 2: Last Clock Edge of Byte 1 to the First Clock Edge of Byte 2 1.5 TCY + 40 40 (Note 1) Requires the use of Parameter #73A. Only if Parameter #71A and #72A are used. 2010 Microchip Technology Inc. DS39770C-page 385 PIC18F85J90 FAMILY I2CTM BUS START/STOP BITS TIMING FIGURE 26-13: SCL 91 93 90 92 SDA Stop Condition Start Condition Note: Refer to Figure 26-3 for load conditions. TABLE 26-18: I2CTM BUS START/STOP BITS REQUIREMENTS (SLAVE MODE) Param. Symbol No. Characteristic 90 TSU:STA Start Condition 91 THD:STA 92 TSU:STO 93 THD:STO Stop Condition Max Units Conditions 4700 -- ns Only relevant for Repeated Start condition ns After this period, the first clock pulse is generated Setup Time 400 kHz mode 600 -- Start Condition 100 kHz mode 4000 -- Hold Time 400 kHz mode 600 -- Stop Condition 100 kHz mode 4700 -- Setup Time Hold Time FIGURE 26-14: 100 kHz mode Min 400 kHz mode 600 -- 100 kHz mode 4000 -- 400 kHz mode 600 -- ns ns I2CTM BUS DATA TIMING 103 102 100 101 SCL 90 106 107 91 92 SDA In 110 109 109 SDA Out Note: Refer to Figure 26-3 for load conditions. DS39770C-page 386 2010 Microchip Technology Inc. PIC18F85J90 FAMILY TABLE 26-19: I2CTM BUS DATA REQUIREMENTS (SLAVE MODE) Param. No. 100 Symbol THIGH 101 TLOW 102 TR 103 TF TSU:STA 90 THD:STA 91 THD:DAT 106 TSU:DAT 107 TSU:STO 92 109 TAA 110 TBUF D102 CB Note 1: 2: Characteristic Clock High Time Clock Low Time Min Max Units 100 kHz mode 4.0 -- s 400 kHz mode 0.6 -- s MSSP Module 1.5 TCY -- s 100 kHz mode 4.7 -- s Conditions 400 kHz mode 1.3 -- s MSSP Module 1.5 TCY -- s 100 kHz mode -- 1000 ns 400 kHz mode 20 + 0.1 CB 300 ns 100 kHz mode -- 300 ns 400 kHz mode 20 + 0.1 CB 300 ns CB is specified to be from 10 to 400 pF Start Condition Setup Time 100 kHz mode 4.7 -- s 400 kHz mode 0.6 -- s Only relevant for Repeated Start condition SDA and SCL Rise Time SDA and SCL Fall Time Start Condition Hold Time Data Input Hold Time Data Input Setup Time 100 kHz mode 4.0 -- s 400 kHz mode 0.6 -- s 100 kHz mode 0 -- ns 400 kHz mode 0 0.9 s 100 kHz mode 250 -- ns 400 kHz mode 100 -- ns Stop Condition Setup Time 100 kHz mode 4.7 -- s 400 kHz mode 0.6 -- s 100 kHz mode -- 3500 ns 400 kHz mode -- -- ns Output Valid from Clock Bus Free Time Bus Capacitive Loading 100 kHz mode 4.7 -- s 400 kHz mode 1.3 -- s -- 400 pF CB is specified to be from 10 to 400 pF After this period, the first clock pulse is generated (Note 2) (Note 1) Time the bus must be free before a new transmission can start As a transmitter, the device must provide this internal minimum delay time to bridge the undefined region (min. 300 ns) of the falling edge of SCL to avoid unintended generation of Start or Stop conditions. A Fast mode I2CTM bus device can be used in a Standard mode I2C bus system, but the requirement, TSU:DAT 250 ns, must then be met. This will automatically be the case if the device does not stretch the LOW period of the SCL signal. If such a device does stretch the LOW period of the SCL signal, it must output the next data bit to the SDA line, TR max. + TSU:DAT = 1000 + 250 = 1250 ns (according to the Standard mode I2C bus specification), before the SCL line is released. 2010 Microchip Technology Inc. DS39770C-page 387 PIC18F85J90 FAMILY MSSP I2CTM BUS START/STOP BITS TIMING WAVEFORMS FIGURE 26-15: SCL 93 91 90 92 SDA Stop Condition Start Condition Note: Refer to Figure 26-3 for load conditions. TABLE 26-20: MSSP I2CTM BUS START/STOP BITS REQUIREMENTS Param. Symbol No. 90 TSU:STA Characteristic Start Condition 100 kHz mode Setup Time 91 THD:STA Start Condition Hold Time 92 TSU:STO Stop Condition Setup Time 93 THD:STO Stop Condition Hold Time Max 2(TOSC)(BRG + 1) -- 400 kHz mode 2(TOSC)(BRG + 1) -- 1 MHz mode(1,2) 2(TOSC)(BRG + 1) -- 100 kHz mode 2(TOSC)(BRG + 1) -- 400 kHz mode 2(TOSC)(BRG + 1) -- 1 MHz mode(1,2) 2(TOSC)(BRG + 1) -- 100 kHz mode 2(TOSC)(BRG + 1) -- 400 kHz mode 2(TOSC)(BRG + 1) -- 1 MHz mode(1,2) 2(TOSC)(BRG + 1) -- 100 kHz mode 2(TOSC)(BRG + 1) -- 400 kHz mode 2(TOSC)(BRG + 1) -- 2(TOSC)(BRG + 1) -- 1 MHz Note 1: 2: Min mode(1,2) Units Conditions Only relevant for Repeated Start condition After this period, the first clock pulse is generated Maximum pin capacitance = 10 pF for all I2CTM pins. A minimum 16 MHz FOSC is required for 1 MHz I2C. FIGURE 26-16: MSSP I2CTM BUS DATA TIMING 103 102 100 101 SCL 90 106 91 107 SDA In 109 109 92 110 SDA Out Note: DS39770C-page 388 Refer to Figure 26-3 for load conditions. 2010 Microchip Technology Inc. PIC18F85J90 FAMILY TABLE 26-21: MSSP I2CTM BUS DATA REQUIREMENTS Param. Symbol No. 100 101 THIGH TLOW Characteristic Clock High Time Min Max 100 kHz mode 2(TOSC)(BRG + 1) -- 400 kHz mode 2(TOSC)(BRG + 1) -- 1 MHz mode(1,2) 2(TOSC)(BRG + 1) -- Clock Low Time 100 kHz mode 2(TOSC)(BRG + 1) -- 400 kHz mode 2(TOSC)(BRG + 1) -- (1,2) 2(TOSC)(BRG + 1) -- 100 kHz mode -- 1000 ns 400 kHz mode 20 + 0.1 CB 300 ns -- 300 ns 100 kHz mode -- 300 ns 400 kHz mode 20 + 0.1 CB 300 ns ns 1 MHz mode 102 TR SDA and SCL Rise Time 1 MHz mode(1,2) 103 TF SDA and SCL Fall Time 1 MHz mode(1,2) 90 91 106 107 TSU:STA Start Condition Setup Time THD:STA Start Condition Hold Time THD:DAT Data Input Hold Time TSU:DAT Data Input Setup Time -- 100 100 kHz mode 2(TOSC)(BRG + 1) -- 400 kHz mode 2(TOSC)(BRG + 1) -- 1 MHz mode(1,2) 2(TOSC)(BRG + 1) -- 100 kHz mode 2(TOSC)(BRG + 1) -- 400 kHz mode 2(TOSC)(BRG + 1) -- 109 TSU:STO Stop Condition Setup Time -- 0 -- ns 400 kHz mode 0 0.9 s 1 MHz mode(1,2) -- -- ns 100 kHz mode 250 -- ns 400 kHz mode 100 -- ns ns TAA Output Valid from Clock -- -- 2(TOSC)(BRG + 1) -- 400 kHz mode 2(TOSC)(BRG + 1) -- 1 MHz mode(1,2) 2(TOSC)(BRG + 1) -- 100 kHz mode -- 3500 ns 400 kHz mode -- 1000 ns (1,2) 110 D102 Note 1: 2: 3: TBUF CB Bus Free Time 1 MHz mode -- -- ns 100 kHz mode 4.7 -- s 400 kHz mode 1.3 -- s 1 MHz mode(1,2) -- -- s -- 400 pF Bus Capacitive Loading CB is specified to be from 10 to 400 pF CB is specified to be from 10 to 400 pF After this period, the first clock pulse is generated 100 kHz mode 100 kHz mode Conditions Only relevant for Repeated Start condition 1 MHz mode(1,2) 2(TOSC)(BRG + 1) 1 MHz mode(1,2) 92 Units (Note 3) Time the bus must be free before a new transmission can start Maximum pin capacitance = 10 pF for all I2CTM pins. A minimum 16 MHz FOSC is required for 1 MHz I2C. A Fast mode I2C bus device can be used in a Standard mode I2C bus system, but parameter #107 250 ns must then be met. This will automatically be the case if the device does not stretch the LOW period of the SCL signal. If such a device does stretch the LOW period of the SCL signal, it must output the next data bit to the SDA line, parameter #102 + parameter #107 = 1000 + 250 = 1250 ns (for 100 kHz mode), before the SCL line is released. 2010 Microchip Technology Inc. DS39770C-page 389 PIC18F85J90 FAMILY FIGURE 26-17: EUSART/AUSART SYNCHRONOUS TRANSMISSION (MASTER/SLAVE) TIMING TXx/CKx pin 121 121 RXx/DTx pin 120 Note: 122 Refer to Figure 26-3 for load conditions. TABLE 26-22: EUSART/AUSART SYNCHRONOUS TRANSMISSION REQUIREMENTS Param No. Symbol Characteristic Min Max Units 120 TCKH2DTV SYNC XMIT (MASTER and SLAVE) Clock High to Data Out Valid -- 40 ns 121 TCKRF Clock Out Rise Time and Fall Time (Master mode) -- 20 ns 122 TDTRF Data Out Rise Time and Fall Time -- 20 ns FIGURE 26-18: Conditions EUSART/AUSART SYNCHRONOUS RECEIVE (MASTER/SLAVE) TIMING TXx/CKx pin 125 RXx/DTx pin 126 Note: Refer to Figure 26-3 for load conditions. TABLE 26-23: EUSART/AUSART SYNCHRONOUS RECEIVE REQUIREMENTS Param. No. Symbol Characteristic 125 TDTV2CKL SYNC RCV (MASTER and SLAVE) Data Hold before CKx (DTx hold time) 126 TCKL2DTL DS39770C-page 390 Data Hold after CKx (DTx hold time) Min Max Units 10 -- ns 15 -- ns Conditions 2010 Microchip Technology Inc. PIC18F85J90 FAMILY TABLE 26-24: A/D CONVERTER CHARACTERISTICS: PIC18F85J90 FAMILY (INDUSTRIAL) Param Symbol No. Characteristic Min Typ Max Units -- -- 10 bits Conditions A01 NR Resolution A03 EIL Integral Linearity Error -- -- <1 LSb VREF 3.0V A04 EDL Differential Linearity Error -- -- <1 LSb VREF 3.0V A06 EOFF Offset Error -- -- <3 LSb VREF 3.0V A07 EGN Gain Error -- -- <3 LSb VREF 3.0V A10 -- Monotonicity A20 VREF Reference Voltage Range (VREFH - VREFL) A21 VREFH A22 Guaranteed(1) -- VSS VAIN VREF 2.0 3 -- -- -- -- V V VDD 3.0V VDD 3.0V Reference Voltage High VSS + VREF -- VDD V VREFL Reference Voltage Low VSS - 0.3V -- VDD - 3.0V V A25 VAIN Analog Input Voltage VREFL -- VREFH V A30 ZAIN Recommended Impedance of Analog Voltage Source -- -- 2.5 k A50 IREF VREF Input Current(2) -- -- -- -- 5 150 A A Note 1: 2: During VAIN acquisition. During A/D conversion cycle. The A/D conversion result never decreases with an increase in the input voltage and has no missing codes. VREFH current is from RA3/AN3/VREF+ pin or VDD, whichever is selected as the VREFH source. VREFL current is from RA2/AN2/VREF- pin or VSS, whichever is selected as the VREFL source. 2010 Microchip Technology Inc. DS39770C-page 391 PIC18F85J90 FAMILY FIGURE 26-19: A/D CONVERSION TIMING BSF ADCON0, GO (Note 2) 131 Q4 130 132 A/D CLK 9 A/D DATA 8 7 ... ... 2 1 0 NEW_DATA OLD_DATA ADRES TCY (Note 1) ADIF GO DONE SAMPLING STOPPED SAMPLE Note 1: If the A/D clock source is selected as RC, a time of TCY is added before the A/D clock starts. This allows the SLEEP instruction to be executed. 2: This is a minimal RC delay (typically 100 ns), which also disconnects the holding capacitor from the analog input. TABLE 26-25: A/D CONVERSION REQUIREMENTS Param Symbol No. Characteristic Min Max Units 25.0(1) s TOSC based, VREF 3.0V A/D RC mode 130 TAD A/D Clock Period 0.7 -- 1 s 131 TCNV Conversion Time (not including acquisition time)(2) 11 12 TAD 132 TACQ Acquisition Time(3) 1.4 -- s 135 TSWC Switching Time from Convert Sample -- (Note 4) 137 TDIS Discharge Time 0.2 -- Note 1: 2: 3: 4: Conditions -40C to +85C s The time of the A/D clock period is dependent on the device frequency and the TAD clock divider. ADRES registers may be read on the following TCY cycle. The time for the holding capacitor to acquire the "New" input voltage when the voltage changes full scale after the conversion (VDD to VSS or VSS to VDD). The source impedance (RS) on the input channels is 50. On the following cycle of the device clock. DS39770C-page 392 2010 Microchip Technology Inc. PIC18F85J90 FAMILY 27.0 PACKAGING INFORMATION 27.1 Package Marking Information 64-Lead TQFP Example XXXXXXXXXX XXXXXXXXXX XXXXXXXXXX YYWWNNN 80-Lead TQFP Example XXXXXXXXXXXX XXXXXXXXXXXX YYWWNNN Legend: XX...X Y YY WW NNN e3 * Note: 18F65J90 -I/PT e3 1010017 PIC18F85J90 -I/PT e3 1010017 Customer-specific information Year code (last digit of calendar year) Year code (last 2 digits of calendar year) Week code (week of January 1 is week `01') Alphanumeric traceability code Pb-free JEDEC designator for Matte Tin (Sn) This package is Pb-free. The Pb-free JEDEC designator ( e3 ) can be found on the outer packaging for this package. In the event the full Microchip part number cannot be marked on one line, it will be carried over to the next line, thus limiting the number of available characters for customer-specific information. 2010 Microchip Technology Inc. DS39770C-page 393 PIC18F85J90 FAMILY 27.2 Package Details The following sections give the technical details of the packages. ' ( !" #$ % & 3& '!&" & 4 && 255***' '5 # * !( 4 ! ! & 4 % & & # & D D1 E e E1 N b 123 NOTE 1 NOTE 2 A c A2 A1 L L1 6&! ' !7'&! 8"') %7 7 #& 9 < & #! 8 89 : ; /1+ = = / / / = / 3&7 & 7 / ; / 3& & 7 # # 4 4 !! & #%% ' 77.. 8 .3 3& 9 ?#& . > 1+ /> 9 7 & 1+ # # 4 ?#& . 1+ # # 4 7 & 1+ > 7 #4 !! = 7 #?#& ) # %& > > > # %& 1&&' > > > ( !" # $% &" ' ()"&'"!&) & #*&& & # + '% ! & ! & ,!- ' ' !! #.#&"# '#% ! &"!!#% ! &"!!! & $ #/'' !# ' ! #& .0/ 1+2 1 !' ! & $ & " !**&"&& ! .32 % ' !("!" *&"&& (%%' & " ! ! * + @/1 DS39770C-page 394 2010 Microchip Technology Inc. PIC18F85J90 FAMILY ' ( !" #$ % & 3& '!&" & 4 && 255***' '5 2010 Microchip Technology Inc. # * !( 4 ! ! & 4 % & & # & DS39770C-page 395 PIC18F85J90 FAMILY ) ' ( ## !" #$ % & 3& '!&" & 4 && 255***' '5 # * !( 4 ! ! & 4 % & & # & D D1 E e E1 N b NOTE 1 12 3 NOTE 2 c L A A2 A1 L1 6&! ' !7'&! 8"') %7 7 #& 9 < & #! 8 89 : @ /1+ = = / / / = / 3&7 & 7 / ; / 3& & 7 # # 4 4 !! & #%% ' 77.. 8 .3 3& 9 ?#& . > 1+ /> 9 7 & 1+ # # 4 ?#& . 1+ # # 4 7 & 1+ > 7 #4 !! = 7 #?#& ) # %& > > > # %& 1&&' > > > ( !" # $% &" ' ()"&'"!&) & #*&& & # + '% ! & ! & ,!- ' ' !! #.#&"# '#% ! &"!!#% ! &"!!! & $ ' ! #& .0/ 1+2 1 !' ! & $ & " !**&"&& ! .32 % ' !("!" *&"&& (%%' & " ! ! #/'' !# * + 1 DS39770C-page 396 2010 Microchip Technology Inc. PIC18F85J90 FAMILY ) ' ( ## !" #$ % & 3& '!&" & 4 && 255***' '5 2010 Microchip Technology Inc. # * !( 4 ! ! & 4 % & & # & DS39770C-page 397 PIC18F85J90 FAMILY NOTES: DS39770C-page 398 2010 Microchip Technology Inc. PIC18F85J90 FAMILY APPENDIX A: REVISION HISTORY Revision A (July 2006) Original data sheet for PIC18F85J90 family devices. Revision B (March 2007) Updated power-down and supply current electrical characteristics and package details illustrations. Revision C (January 2010) Updated electrical characteristics and package detail illustrations. Minor text edits throughout document. 2010 Microchip Technology Inc. DS39770C-page 399 PIC18F85J90 FAMILY APPENDIX B: MIGRATION BETWEEN HIGH-END DEVICE FAMILIES ences which should be considered when migrating an application across device families to achieve a new design goal. These are summarized in Table B-1. The areas of difference, which could be a major impact on migration, are discussed in greater detail later in this section. Devices in the PIC18F85J90 and PIC18F8490 families are very similar in their functions and feature sets. However, there are some potentially important differ- TABLE B-1: NOTABLE DIFFERENCES BETWEEN PIC18F8490 AND PIC18F85J90 FAMILIES Characteristic Operating Frequency Supply Voltage Operating Current Program Memory Size (maximum) Program Memory Endurance Program Memory Retention Programming Time (Normalized) PIC18F85J90 Family PIC18F8490 Family 40 MHz @ 2.35V 40 MHz @ 4.2V 2.0V-3.6V, Dual Voltage Requirement 2.0V-5.5V Low Lower 32 Kbytes 16 Kbytes 1,000 Write/Erase Cycles (typical) 100,000 Write/Erase Cycles (typical) 20 Years (minimum) 40 Years (minimum) 43.8 s/byte (2.8 ms/64-byte block) 15.6 s/byte (1 ms/64-byte block) I/O Sink/Source at 25 mA PORTB and PORTC Only All Ports Input Voltage Tolerance on I/O Pins 5.5V on Digital Only Pins VDD on All I/O Pins I/O 67 66 LCD Outputs (maximum pixels, segments x commons) 192 192 LCD Bias Generation 4 Modes 1 Mode Implemented; Includes Voltage Boost Not Available PORTB, PORTD, PORTE and PORTJ PORTB Available on USARTs, SPI and CCP Output Pins Not Available Limited Primary Options (EC, HS, PLL); Flexible Internal Oscillator (INTOSC and INTRC) More Primary Options (EC, HS, XT, LP, RC, PLL); Flexible Internal Oscillator (INTOSC and INTRC) Programming Entry Low Voltage, Key Sequence VPP and LVP Code Protection Single Block, All or Nothing Multiple Code Protection Blocks Stored in Last 4 Words of Program Memory space Stored in Configuration Space, Starting at 300000h LCD Voltage Regulator Pull-ups Open-Drain Output Option Oscillator Options Configuration Words 200 s (typical) Start-up Time from Sleep Power-up Timer Data EEPROM 10 s (typical) with Voltage Regulator Disabled 10 s (typical) Always on Configurable Use Self-Programming Not Available BOR Simple BOR with Voltage Regulator Separate Programmable BOR LVD Integrated with Voltage Regulator Separate Programmable Module A/D Channels 12 12 A/D Calibration Self-Calibration Feature Software Look-up Table Not available Available In-Circuit Emulation DS39770C-page 400 2010 Microchip Technology Inc. PIC18F85J90 FAMILY B.1 Power Requirement Differences The most significant difference between the PIC18F85J90 and PIC18F8490 device families is the power requirements. PIC18F85J90 family devices are designed on a smaller process. This results in lower maximum voltage and higher leakage current. The operating voltage range for PIC18F85J90 devices is 2.0V to 3.6V. In addition, these devices have split power requirements: one for the core logic and one for the I/O. One of the VDD pins is separated for the core logic supply (VDDCORE). This pin has specific voltage and capacitor requirements as described in Section 26.0 "Electrical Characteristics". B.2 Oscillator Differences PIC18F8490 and PIC18F85J90 family devices share a similar range of oscillator options. The major difference is that PIC18F85J90 family devices support a smaller number of primary (external) oscillator options, namely HS and EC Oscillator modes. While both device families have an internal PLL that can be used with the primary oscillators, the PLL for the PIC18F85J90 family is not enabled as a device configuration option. Instead, it must be enabled in software. The clocking differences should be considered when making a conversion between the PIC18F8490 and PIC18F85J90 device families. B.3 LCD Module When converting an LCD application between the PIC18F85J90 and the PIC18F8490 families, the following things must be considered: * Available Segments: The module for PIC18F65J90 devices supports 33 segments, as opposed to 32 segments in PIC18F6490 devices. (The 80-pin devices of both families support 48 segments. All devices support 4 commons.) * Bias Generation: The PIC18F85J90 version of the module also incorporates its own independent voltage regulator, which supports 4 circuit configurations for bias generation, voltage boost to support displays that operate above device VDD and software contrast control. 2010 Microchip Technology Inc. * Additional LCD Function Pins: The PIC18F85J90 family of devices adds 3 additional LCD function pins in comparison to the PIC18F8490 family. The additional pins are associated with LCD bias generation: - LCDBIAS0 (RG0) - VLCAP1 (RG2) - VLCPA2 (RG3) * Segment Assignments: Eight of the LCD segment functions have been relocated to different I/O pins than in PIC18F8490 devices. These segments are listed in Table B-2. * Other Considerations: In all LCD applications, the connections of PIC18F85J90 devices to external components for LCD bias generation are different than PIC18F8490 devices. The addition of the LCDBIAS0 output requires that this pin be included in bias component configurations. A more complete discussion is provided in Section 16.3 "LCD Bias Generation". The simultaneous use of the external Timer1 oscillator and Segment 32 is not allowed in PIC18F85J90 devices, since these functions are shared on the same pin. TABLE B-2: LCD Segment ASSIGNMENTS OF MOVED LCD SEGMENTS PIC18F8490 PIC18F85J90 SEG16 RA2 RC4 SEG17 RA3 RC3 SEG18 RF0 RA1 SEG27 RG3 RC6 SEG28 RG2 RC7 SEG29 RG0 RB5 SEG30 RG0 RB0 RJ0 RC1 SEG32 Note: Refer to the pinout diagrams for pin locations of I/O ports. DS39770C-page 401 PIC18F85J90 FAMILY B.4 Pin Differences B.5 Other Peripherals Besides the LCD pinout differences already described, there are other differences in the pinouts between the PIC18F85J90 and the PIC18F8490 families: Peripherals must also be considered when making a conversion between the PIC18F85J90 and the PIC18F8490 families: * Input voltage tolerance * Output current capabilities * Available I/O * A/D Converter: The converter for PIC18F85J90 devices require a calibration step prior to normal operation. * Data EEPROM: PIC18F85J90 devices do not have this module but offer self-programming capability. * BOR: PIC18F85J90 devices do not have a programmable BOR. Simple brown-out capability is provided through the use of the internal voltage regulator. * LVD: PIC18F85J90 devices do not have this module. A limited, fixed setpoint capability is provided through the use of the internal voltage regulator. Pins on the PIC18F85J90 that have digital only input capability will tolerate voltages up to 5.5V, and are thus, tolerant to voltages above VDD. Table 10-1 in Section 10.1 "I/O Port Pin Capabilities" contains the complete list. In addition to input differences, there are output differences as well. PIC18F85J90 devices have three classes of pin output current capability: high, medium and low. Not all I/O pins can source or sink equal levels of current. Only PORTB and PORTC support the 25 mA source/sink capability that is supported by all output pins on the PIC18F8490. Table 10-1 in Section 10.1 "I/O Port Pin Capabilities" contains the complete list of output capabilities. Finally, the pins associated with the CCP, EUSART/AUSART and SPI peripherals can be configured by the user as open-drain outputs. This allows for simpler interfacing with external devices operating at higher voltages. This capability is not directly equivalent to any feature on the PIC18F8490 family. There are also differences in the implementation of some ports on PIC18F85J90 devices. While the total number of general purpose I/O pins are very similar (67 vs. 66), the implementation of individual pins has notable differences: * The MCLR pin is dedicated only to MCLR and cannot be configured as an input (RG5) as it can on PIC18F8490 devices. * RF0 does not exist on PIC18F85J90 devices. * RE0, RE1 and RE3 are implemented on PIC18F85J90 devices, but not PIC18F8490 devices. All of these pin differences (including power pin differences) should be accounted for when making a conversion between PIC18F8490 and PIC18F85J90 devices. DS39770C-page 402 2010 Microchip Technology Inc. PIC18F85J90 FAMILY INDEX A A/D ................................................................................... 271 A/D Converter Interrupt, Configuring ....................... 275 Acquisition Requirements ........................................ 276 ADCAL Bit ................................................................ 279 ADCON0 Register .................................................... 271 ADCON1 Register .................................................... 271 ADCON2 Register .................................................... 271 ADRESH Register ............................................ 271, 274 ADRESL Register .................................................... 271 Analog Port Pins, Configuring .................................. 277 Associated Registers ............................................... 279 Automatic Acquisition Time ...................................... 277 Calibration ................................................................ 279 Configuring the Module ............................................ 275 Conversion Clock (TAD) ........................................... 277 Conversion Requirements ....................................... 392 Conversion Status (GO/DONE Bit) .......................... 274 Conversions ............................................................. 278 Converter Characteristics ........................................ 391 Operation in Power-Managed Modes ...................... 279 Special Event Trigger (CCP) .................................... 278 Use of the CCP2 Trigger .......................................... 278 Absolute Maximum Ratings ............................................. 359 AC (Timing) Characteristics ............................................. 374 Load Conditions for Device Timing Specifications ................................................... 375 Parameter Symbology ............................................. 374 Temperature and Voltage Specifications ................. 375 Timing Conditions .................................................... 375 ACKSTAT ........................................................................ 225 ACKSTAT Status Flag ..................................................... 225 ADCAL Bit ........................................................................ 279 ADCON0 Register ............................................................ 271 GO/DONE Bit ........................................................... 274 ADCON1 Register ............................................................ 271 ADCON2 Register ............................................................ 271 ADDFSR .......................................................................... 348 ADDLW ............................................................................ 311 Addressable Universal Synchronous Asynchronous Receiver Transmitter (AUSART). See AUSART. ADDULNK ........................................................................ 348 ADDWF ............................................................................ 311 ADDWFC ......................................................................... 312 ADRESH Register ............................................................ 271 ADRESL Register .................................................... 271, 274 Analog-to-Digital Converter. See A/D. ANDLW ............................................................................ 312 ANDWF ............................................................................ 313 Assembler MPASM Assembler .................................................. 356 AUSART Asynchronous Mode ................................................ 262 Associated Registers, Receive ........................ 265 Associated Registers, Transmit ....................... 263 Receiver ........................................................... 264 Setting up 9-Bit Mode with Address Detect ..... 264 Transmitter ....................................................... 262 2010 Microchip Technology Inc. Baud Rate Generator (BRG) ................................... 260 Associated Registers ....................................... 260 Baud Rate Error, Calculating ........................... 260 Baud Rates, Asynchronous Modes ................. 261 High Baud Rate Select (BRGH Bit) ................. 260 Operation in Power-Managed Modes .............. 260 Sampling ......................................................... 260 Synchronous Master Mode ...................................... 266 Associated Registers, Receive ........................ 268 Associated Registers, Transmit ....................... 267 Reception ........................................................ 268 Transmission ................................................... 266 Synchronous Slave Mode ........................................ 269 Associated Registers, Receive ........................ 270 Associated Registers, Transmit ....................... 269 Reception ........................................................ 270 Transmission ................................................... 269 Auto-Wake-up on Sync Break Character ......................... 249 B Baud Rate Generator ...................................................... 221 BC .................................................................................... 313 BCF ................................................................................. 314 BF .................................................................................... 225 BF Status Flag ................................................................. 225 Bias Generation (LCD) Charge Pump Design Considerations ..................... 173 Block Diagrams A/D ........................................................................... 274 Analog Input Model .................................................. 275 AUSART Receive .................................................... 264 AUSART Transmit ................................................... 262 Baud Rate Generator .............................................. 221 Capture Mode Operation ......................................... 156 Comparator Analog Input Model .............................. 285 Comparator I/O Operating Modes ........................... 282 Comparator Output .................................................. 284 Comparator Voltage Reference ............................... 288 Comparator Voltage Reference Output Buffer Example ................................................ 289 Compare Mode Operation ....................................... 157 Connections for On-Chip Voltage Regulator ........... 299 Device Clock .............................................................. 35 EUSART Receive .................................................... 247 EUSART Transmit ................................................... 245 External Power-on Reset Circuit (Slow VDD Power-up) ........................................ 53 Fail-Safe Clock Monitor ........................................... 301 Generic I/O Port Operation ...................................... 115 Interrupt Logic .......................................................... 100 LCD Clock Generation ............................................. 168 LCD Driver Module .................................................. 163 LCD Regulator Connections (M0 and M1) .............. 170 MSSP (I2C Master Mode) ........................................ 219 MSSP (I2C Mode) .................................................... 200 MSSP (SPI Mode) ................................................... 191 On-Chip Reset Circuit ................................................ 51 PIC18F6XJ90 ............................................................ 12 PIC18F8XJ90 ............................................................ 13 PLL ............................................................................ 40 PWM Operation (Simplified) .................................... 159 DS39770C-page 403 PIC18F85J90 FAMILY Reads from Flash Program Memory .......................... 91 Resistor Ladder Configurations for M2 .................... 171 Resistor Ladder Configurations for M3 .................... 172 Single Comparator ................................................... 283 SPI Master/Slave Connection .................................. 195 Table Read Operation ................................................ 87 Table Write Operation ................................................ 88 Table Writes to Flash Program Memory .................... 93 Timer0 in 16-Bit Mode .............................................. 138 Timer0 in 8-Bit Mode ................................................ 138 Timer1 (16-Bit Read/Write Mode) ............................ 142 Timer1 (8-Bit Mode) ................................................. 142 Timer2 ...................................................................... 148 Timer3 (16-Bit Read/Write Mode) ............................ 150 Timer3 (8-Bit Mode) ................................................. 150 Watchdog Timer ....................................................... 297 BN .................................................................................... 314 BNC .................................................................................. 315 BNN .................................................................................. 315 BNOV ............................................................................... 316 BNZ .................................................................................. 316 BOR. See Brown-out Reset. BOV .................................................................................. 319 BRA .................................................................................. 317 Break Character (12-Bit) Transmit and Receive .............. 250 BRG. See Baud Rate Generator. BRGH Bit TXSTA1 Register ..................................................... 239 TXSTA2 Register ..................................................... 260 Brown-out Reset (BOR) ..................................................... 53 and On-Chip Voltage Regulator ............................... 300 Detecting .................................................................... 53 BSF .................................................................................. 317 BTFSC ............................................................................. 318 BTFSS .............................................................................. 318 BTG .................................................................................. 319 BZ ..................................................................................... 320 C C Compilers MPLAB C18 ............................................................. 356 Calibration (A/D Converter) .............................................. 279 CALL ................................................................................ 320 CALLW ............................................................................. 349 Capture (CCP Module) ..................................................... 156 Associated Registers ............................................... 158 CCP Pin Configuration ............................................. 156 CCPR2H:CCPR2L Registers ................................... 156 Software Interrupt .................................................... 156 Timer1/Timer3 Mode Selection ................................ 156 Capture/Compare/PWM (CCP) ........................................ 153 Capture Mode. See Capture. CCP Mode and Timer Resources ............................ 154 CCPRxH Register .................................................... 154 CCPRxL Register ..................................................... 154 Compare Mode. See Compare. Configuration ............................................................ 154 Interaction of CCP1 and CCP2 for Timer Resources .............................................. 155 Interconnect Configurations ..................................... 154 Clock Sources .................................................................... 37 Default System Clock on Reset ................................. 38 Selection Using OSCCON Register ........................... 38 CLRF ................................................................................ 321 CLRWDT .......................................................................... 321 DS39770C-page 404 Code Examples 16 x 16 Signed Multiply Routine ................................ 98 16 x 16 Unsigned Multiply Routine ............................ 98 8 x 8 Signed Multiply Routine .................................... 97 8 x 8 Unsigned Multiply Routine ................................ 97 Changing Between Capture Prescalers ................... 156 Computed GOTO Using an Offset Value ................... 67 Erasing a Flash Program Memory Block ................... 92 Fast Register Stack ................................................... 67 How to Clear RAM (Bank 1) Using Indirect Addressing ............................................ 80 Implementing a Real-Time Clock Using a Timer1 Interrupt Service ............................... 145 Initializing PORTA .................................................... 116 Initializing PORTB .................................................... 118 Initializing PORTC ................................................... 121 Initializing PORTD ................................................... 124 Initializing PORTE .................................................... 126 Initializing PORTF .................................................... 128 Initializing PORTG ................................................... 131 Initializing PORTH ................................................... 133 Initializing PORTJ .................................................... 135 Loading the SSPBUF (SSPSR) Register ................. 194 Reading a Flash Program Memory Word .................. 91 Saving STATUS, WREG and BSR Registers in RAM ............................................. 114 Writing to Flash Program Memory ............................. 94 Code Protection ............................................................... 291 COMF .............................................................................. 322 Comparator ...................................................................... 281 Analog Input Connection Considerations ................ 285 Associated Registers ............................................... 285 Configuration ........................................................... 282 Effects of a Reset .................................................... 284 Interrupts ................................................................. 284 Operation ................................................................. 283 Operation During Sleep ........................................... 284 Outputs .................................................................... 283 Reference ................................................................ 283 External Signal ................................................ 283 Internal Signal .................................................. 283 Response Time ........................................................ 283 Comparator Specifications ............................................... 372 Comparator Voltage Reference ....................................... 287 Accuracy and Error .................................................. 288 Associated Registers ............................................... 289 Configuring .............................................................. 287 Connection Considerations ...................................... 288 Effects of a Reset .................................................... 288 Operation During Sleep ........................................... 288 Compare (CCP Module) .................................................. 157 Associated Registers ............................................... 158 CCP Pin Configuration ............................................. 157 CCPR2 Register ...................................................... 157 Software Interrupt .................................................... 157 Special Event Trigger .............................. 151, 157, 278 Timer1/Timer3 Mode Selection ................................ 157 Computed GOTO ............................................................... 67 Configuration Bits ............................................................ 291 Configuration Mismatch (CM) ............................................ 53 Configuration Register Protection .................................... 303 2010 Microchip Technology Inc. PIC18F85J90 FAMILY Core Features Easy Migration ............................................................. 9 Extended Instruction Set .............................................. 9 Memory Options ........................................................... 9 nanoWatt Technology .................................................. 9 Oscillator Options and Features .................................. 9 CPFSEQ .......................................................................... 322 CPFSGT .......................................................................... 323 CPFSLT ........................................................................... 323 Crystal Oscillator/Ceramic Resonator ................................ 39 Customer Change Notification Service ............................ 413 Customer Notification Service .......................................... 413 Customer Support ............................................................ 413 D Data Addressing Modes ..................................................... 80 Comparing Addressing Modes with the Extended Instruction Set Enabled ............... 84 Direct .......................................................................... 80 Indexed Literal Offset ................................................. 83 BSR ................................................................... 85 Instructions Affected .......................................... 83 Mapping Access Bank ....................................... 85 Indirect ....................................................................... 80 Inherent and Literal .................................................... 80 Data Memory ..................................................................... 70 Access Bank .............................................................. 73 Bank Select Register (BSR) ....................................... 70 Extended Instruction Set ............................................ 83 General Purpose Registers ........................................ 73 Memory Maps PIC18FX3J90/X4J90 Devices ........................... 71 PIC18FX5J90 Devices ....................................... 72 Special Function Registers ................................ 74 Special Function Registers ........................................ 74 DAW ................................................................................. 324 DC Characteristics ........................................................... 370 Power-Down and Supply Current ............................ 362 Supply Voltage ......................................................... 361 DCFSNZ .......................................................................... 325 DECF ............................................................................... 324 DECFSZ ........................................................................... 325 Default System Clock ......................................................... 38 Details on Individual Family Members ............................... 10 Development Support ...................................................... 355 Device Overview .................................................................. 9 Features (64-Pin Devices) ......................................... 11 Features (80-Pin Devices) ......................................... 11 Direct Addressing ............................................................... 81 E Effect on Standard PIC18 Instructions ............................. 352 Effects of Power-Managed Modes on Various Clock Sources ............................................... 42 Electrical Characteristics .................................................. 359 Enhanced Universal Synchronous Asynchronous Receiver Transmitter (EUSART). See EUSART. ENVREG Pin .................................................................... 299 2010 Microchip Technology Inc. Equations 16 x 16 Signed Multiplication Algorithm ..................... 98 16 x 16 Unsigned Multiplication Algorithm ................. 98 A/D Acquisition Time ............................................... 276 A/D Minimum Charging Time .................................. 276 Calculating the Minimum Required Acquisition Time .............................................. 276 LCD Static and Dynamic Current ............................ 173 Errata ................................................................................... 7 EUSART Asynchronous Mode ................................................ 245 12-Bit Break Transmit and Receive ................. 250 Associated Registers, Receive ........................ 248 Associated Registers, Transmit ....................... 246 Auto-Wake-up on Sync Break ......................... 249 Receiver .......................................................... 247 Setting up 9-Bit Mode with Address Detect ..... 247 Transmitter ...................................................... 245 Baud Rate Generator (BRG) ................................... 239 Associated Registers ....................................... 240 Auto-Baud Rate Detect .................................... 243 Baud Rate Error, Calculating ........................... 240 Baud Rates, Asynchronous Modes ................. 241 High Baud Rate Select (BRGH Bit) ................. 239 Operation in Power-Managed Modes .............. 239 Sampling ......................................................... 239 Synchronous Master Mode ...................................... 251 Associated Registers, Receive ........................ 253 Associated Registers, Transmit ....................... 252 Reception ........................................................ 253 Transmission ................................................... 251 Synchronous Slave Mode ........................................ 254 Associated Registers, Receive ........................ 255 Associated Registers, Transmit ....................... 254 Reception ........................................................ 255 Transmission ................................................... 254 Extended Instruction Set ADDFSR .................................................................. 348 ADDULNK ............................................................... 348 CALLW .................................................................... 349 MOVSF .................................................................... 349 MOVSS .................................................................... 350 PUSHL ..................................................................... 350 SUBFSR .................................................................. 351 SUBULNK ................................................................ 351 External Oscillator Modes .................................................. 39 EC Modes .................................................................. 40 HS Modes .................................................................. 39 F Fail-Safe Clock Monitor ........................................... 291, 301 Exiting Fail-Safe Operation ...................................... 302 Interrupts in Power-Managed Modes ...................... 302 POR or Wake-up From Sleep .................................. 302 WDT During Oscillator Failure ................................. 301 Fast Register Stack ........................................................... 67 Firmware Instructions ...................................................... 305 DS39770C-page 405 PIC18F85J90 FAMILY Flash Program Memory ...................................................... 87 Associated Registers ................................................. 95 Control Registers ....................................................... 88 EECON1 and EECON2 ..................................... 88 TABLAT (Table Latch) Register ......................... 90 TBLPTR (Table Pointer) Register ...................... 90 Erase Sequence ........................................................ 92 Erasing ....................................................................... 92 Operation During Code-Protect ................................. 95 Reading ...................................................................... 91 Table Pointer Boundaries Based on Operation ........................ 90 Table Pointer Boundaries .......................................... 90 Table Reads and Table Writes .................................. 87 Write Sequence ......................................................... 93 Writing ........................................................................ 93 Unexpected Termination .................................... 95 Write Verify ........................................................ 95 FSCM. See Fail-Safe Clock Monitor. G GOTO ............................................................................... 326 H Hardware Multiplier ............................................................ 97 Introduction ................................................................ 97 Operation ................................................................... 97 Performance Comparison .......................................... 97 I I/O Ports ........................................................................... 115 Input Voltage Considerations ................................... 115 Open-Drain Outputs ................................................. 116 Output Pin Drive ....................................................... 115 Pin Capabilities ........................................................ 115 Pull-up Configuration ............................................... 116 I2C Mode (MSSP) ............................................................ 200 Acknowledge Sequence Timing ............................... 228 Associated Registers ............................................... 234 Baud Rate Generator ............................................... 221 Bus Collision During a Repeated Start Condition .................. 232 During a Stop Condition ................................... 233 Clock Arbitration ....................................................... 222 Clock Stretching ....................................................... 214 10-Bit Slave Receive Mode (SEN = 1) ............. 214 10-Bit Slave Transmit Mode ............................. 214 7-Bit Slave Receive Mode (SEN = 1) ............... 214 7-Bit Slave Transmit Mode ............................... 214 Clock Synchronization and the CKP Bit ................... 215 Effects of a Reset ..................................................... 229 General Call Address Support ................................. 218 I2C Clock Rate w/BRG ............................................. 221 Master Mode ............................................................ 219 Baud Rate Generator ....................................... 221 Operation ......................................................... 220 Reception ......................................................... 225 Repeated Start Condition Timing ..................... 224 Start Condition Timing ..................................... 223 Transmission .................................................... 225 Multi-Master Communication, Bus Collision and Arbitration .................................................. 229 Multi-Master Mode ................................................... 229 Operation ................................................................. 205 Read/Write Bit Information (R/W Bit) ............... 205, 207 Registers .................................................................. 200 DS39770C-page 406 Serial Clock (SCK/SCL) ........................................... 207 Slave Mode .............................................................. 205 Addressing ....................................................... 205 Addressing Masking ........................................ 206 Reception ........................................................ 207 Transmission ................................................... 207 Sleep Operation ....................................................... 229 Stop Condition Timing ............................................. 228 INCF ................................................................................ 326 INCFSZ ............................................................................ 327 In-Circuit Debugger .......................................................... 303 In-Circuit Serial Programming (ICSP) ...................... 291, 303 Indexed Literal Offset Addressing and Standard PIC18 Instructions ............................. 352 Indexed Literal Offset Mode ............................................. 352 Indirect Addressing ............................................................ 81 INFSNZ ............................................................................ 327 Initialization Conditions for all Registers ...................... 57-59 Instruction Cycle ................................................................ 68 Clocking Scheme ....................................................... 68 Flow/Pipelining ........................................................... 68 Instruction Set .................................................................. 305 ADDLW .................................................................... 311 ADDWF .................................................................... 311 ADDWF (Indexed Literal Offset Mode) .................... 353 ADDWFC ................................................................. 312 ANDLW .................................................................... 312 ANDWF .................................................................... 313 BC ............................................................................ 313 BCF ......................................................................... 314 BN ............................................................................ 314 BNC ......................................................................... 315 BNN ......................................................................... 315 BNOV ...................................................................... 316 BNZ ......................................................................... 316 BOV ......................................................................... 319 BRA ......................................................................... 317 BSF .......................................................................... 317 BSF (Indexed Literal Offset Mode) .......................... 353 BTFSC ..................................................................... 318 BTFSS ..................................................................... 318 BTG ......................................................................... 319 BZ ............................................................................ 320 CALL ........................................................................ 320 CLRF ....................................................................... 321 CLRWDT ................................................................. 321 COMF ...................................................................... 322 CPFSEQ .................................................................. 322 CPFSGT .................................................................. 323 CPFSLT ................................................................... 323 DAW ........................................................................ 324 DCFSNZ .................................................................. 325 DECF ....................................................................... 324 DECFSZ .................................................................. 325 Extended Instructions .............................................. 347 Considerations when Enabling ........................ 352 Syntax .............................................................. 347 Use with MPLAB IDE Tools ............................. 354 General Format ........................................................ 307 GOTO ...................................................................... 326 INCF ........................................................................ 326 INCFSZ .................................................................... 327 INFSNZ .................................................................... 327 IORLW ..................................................................... 328 IORWF ..................................................................... 328 2010 Microchip Technology Inc. PIC18F85J90 FAMILY LFSR ........................................................................ 329 MOVF ....................................................................... 329 MOVFF .................................................................... 330 MOVLB .................................................................... 330 MOVLW ................................................................... 331 MOVWF ................................................................... 331 MULLW .................................................................... 332 MULWF .................................................................... 332 NEGF ....................................................................... 333 NOP ......................................................................... 333 Opcode Field Descriptions ....................................... 306 POP ......................................................................... 334 PUSH ....................................................................... 334 RCALL ..................................................................... 335 RESET ..................................................................... 335 RETFIE .................................................................... 336 RETLW .................................................................... 336 RETURN .................................................................. 337 RLCF ........................................................................ 337 RLNCF ..................................................................... 338 RRCF ....................................................................... 338 RRNCF .................................................................... 339 SETF ........................................................................ 339 SETF (Indexed Literal Offset Mode) ........................ 353 SLEEP ..................................................................... 340 Standard Instructions ............................................... 305 SUBFWB .................................................................. 340 SUBLW .................................................................... 341 SUBWF .................................................................... 341 SUBWFB .................................................................. 342 SWAPF .................................................................... 342 TBLRD ..................................................................... 343 TBLWT ..................................................................... 344 TSTFSZ ................................................................... 345 XORLW .................................................................... 345 XORWF .................................................................... 346 INTCON Register RBIF Bit .................................................................... 118 INTCON Registers ........................................................... 101 Inter-Integrated Circuit. See I2C Mode. Internal Oscillator Block ..................................................... 41 Adjustment ................................................................. 41 INTOSC Frequency Drift ............................................ 41 INTOSC Output Frequency ........................................ 41 OSC1, OSC2 Pin Configuration ................................. 41 Internal RC Oscillator Use with WDT .......................................................... 297 Internal Voltage Regulator Specifications ........................ 373 Internet Address ............................................................... 413 Interrupt Sources ............................................................. 291 A/D Conversion Complete ....................................... 275 Capture Complete (CCP) ......................................... 156 Compare Complete (CCP) ....................................... 157 Interrupt-on-Change (RB7:RB4) .............................. 118 TMR0 Overflow ........................................................ 139 TMR1 Overflow ........................................................ 141 TMR2 to PR2 Match (PWM) .................................... 159 TMR3 Overflow ................................................ 149, 151 Interrupts ............................................................................ 99 During, Context Saving ............................................ 114 INTx Pin ................................................................... 114 PORTB, Interrupt-on-Change .................................. 114 TMR0 ....................................................................... 114 Interrupts, Flag Bits Interrupt-on-Change (RB7:RB4) Flag (RBIF Bit) ..... 118 2010 Microchip Technology Inc. INTOSC, INTRC. See Internal Oscillator Block. IORLW ............................................................................. 328 IORWF ............................................................................. 328 IPR Registers ................................................................... 110 L LCD Associated Registers ............................................... 189 Bias Generation ....................................................... 169 Bias Configurations ......................................... 170 M0 and M1 .............................................. 170 M2 ........................................................... 171 M3 ........................................................... 172 Bias Types ....................................................... 169 LCD Voltage Regulator .................................... 169 Charge Pump .................................................. 170, 173 Clock Source Selection ........................................... 168 Configuring the Module ........................................... 188 Frame Frequency .................................................... 174 Interrupts ................................................................. 186 LCDCON Register ................................................... 164 LCDDATA Registers ................................................ 164 LCDPS Register ...................................................... 164 LCDREG Register ................................................... 164 LCDSE Registers .................................................... 164 Multiplex Types ........................................................ 173 Operation During Sleep ........................................... 187 Pixel Control ............................................................ 173 Segment Enables .................................................... 173 Waveform Generation ............................................. 174 LCD Driver ......................................................................... 10 LCDCON Register ........................................................... 164 LCDDATA Registers ........................................................ 164 LCDPS Register .............................................................. 164 LCDREG Register ........................................................... 164 LCDSE Registers ............................................................. 164 LFSR ............................................................................... 329 Liquid Crystal Display (LCD) Driver ................................. 163 Low-Voltage Detection ..................................................... 299 M Master Clear (MCLR) ......................................................... 53 Master Synchronous Serial Port (MSSP). See MSSP. Memory Organization ........................................................ 63 Data Memory ............................................................. 70 Program Memory ....................................................... 63 Memory Programming Requirements .............................. 372 Microchip Internet Web Site ............................................. 413 MOVF .............................................................................. 329 MOVFF ............................................................................ 330 MOVLB ............................................................................ 330 MOVLW ........................................................................... 331 MOVSF ............................................................................ 349 MOVSS ............................................................................ 350 MOVWF ........................................................................... 331 MPLAB ASM30 Assembler, Linker, Librarian .................. 356 MPLAB Integrated Development Environment Software ............................................. 355 MPLAB PM3 Device Programmer ................................... 358 MPLAB REAL ICE In-Circuit Emulator System ............... 357 MPLINK Object Linker/MPLIB Object Librarian ............... 356 DS39770C-page 407 PIC18F85J90 FAMILY MSSP ACK Pulse ........................................................ 205, 207 Control Registers (general) ...................................... 191 Module Overview ..................................................... 191 SSPBUF Register .................................................... 196 SSPSR Register ...................................................... 196 MULLW ............................................................................ 332 MULWF ............................................................................ 332 N NEGF ............................................................................... 333 NOP ................................................................................. 333 Notable Differences Between PIC18F8490 and PIC18F85J90 Families ...................................... 400 LCD Module ............................................................. 401 Oscillator Options ..................................................... 401 Other Peripherals ..................................................... 402 Pin Differences ......................................................... 402 Power Requirements ............................................... 401 O Oscillator Configuration ...................................................... 35 EC .............................................................................. 35 ECPLL ........................................................................ 35 HS .............................................................................. 35 HSPLL ........................................................................ 35 Internal Oscillator Block ............................................. 41 INTOSC ..................................................................... 35 INTRC ........................................................................ 35 Oscillator Selection .......................................................... 291 Oscillator Start-up Timer (OST) ......................................... 42 Oscillator Switching ............................................................ 37 Oscillator Transitions .......................................................... 38 Oscillator, Timer1 ..................................................... 141, 151 Oscillator, Timer3 ............................................................. 149 P Packaging ........................................................................ 393 Details ...................................................................... 394 Marking .................................................................... 393 PIE Registers ................................................................... 107 Pin Functions AVDD .......................................................................... 29 AVDD .......................................................................... 20 AVSS .......................................................................... 29 AVSS .......................................................................... 20 ENVREG .............................................................. 20, 29 LCDBIAS3 ............................................................ 18, 25 MCLR ................................................................... 14, 21 OSC1/CLKI/RA7 .................................................. 14, 21 OSC2/CLKO/RA6 ................................................ 14, 21 RA0/AN0 .............................................................. 14, 21 RA1/AN1/SEG18 ................................................. 14, 21 RA2/AN2/VREF- .................................................... 14, 21 RA3/AN3/VREF+ ................................................... 14, 21 RA4/T0CKI/SEG14 .............................................. 14, 21 RA5/AN4/SEG15 ................................................. 14, 21 RB0/INT0/SEG30 ................................................. 15, 22 RB1/INT1/SEG8 ................................................... 15, 22 RB2/INT2/SEG9 ................................................... 15, 22 RB3/INT3/SEG10 ................................................. 15, 22 RB4/KBI0/SEG11 ................................................. 15, 22 RB5/KBI1/SEG29 ................................................. 15, 22 RB6/KBI2/PGC .................................................... 15, 22 RB7/KBI3/PGD .................................................... 15, 22 RC0/T1OSO/T13CKI ........................................... 16, 23 DS39770C-page 408 RC1/T1OSI/CCP2/SEG32 ................................... 16, 23 RC2/CCP1/SEG13 .............................................. 16, 23 RC3/SCK/SCL/SEG17 ......................................... 16, 23 RC4/SDI/SDA/SEG16 .......................................... 16, 23 RC5/SDO/SEG12 ................................................ 16, 23 RC6/TX1/CK1/SEG27 ......................................... 16, 23 RC7/RX1/DT1/SEG28 ......................................... 16, 23 RD0/SEG0 ........................................................... 17, 24 RD0/SEG1 ........................................................... 17, 24 RD2/SEG2 ........................................................... 17, 24 RD3/SEG3 ........................................................... 17, 24 RD4/SEG4 ........................................................... 17, 24 RD5/SEG5 ........................................................... 17, 24 RD6/SEG6 ........................................................... 17, 24 RD7/SEG7 ........................................................... 17, 24 RE0/LCDBIAS1 ................................................... 18, 25 RE1/LCDBIAS2 ................................................... 18, 25 RE3/COM0 .......................................................... 18, 25 RE4/COM1 .......................................................... 18, 25 RE5/COM2 .......................................................... 18, 25 RE6/COM3 .......................................................... 18, 25 RE7/CCP2/SEG31 ............................................... 18, 25 RF1/AN6/C2OUT/SEG19 .................................... 19, 26 RF2/AN7/C1OUT/SEG20 .................................... 19, 26 RF3/AN8/SEG21 ................................................. 19, 26 RF4/AN9/SEG22 ................................................. 19, 26 RF5/AN10/CVREF/SEG23 .................................... 19, 26 RF6/AN11/SEG24 ............................................... 19, 26 RF7/AN5/SS/SEG25 ............................................ 19, 26 RG0/LCDBIAS0 ................................................... 20, 27 RG1/TX2/CK2 ...................................................... 20, 27 RG2/RX2/DT2/VLCAP1 ......................................... 27, 20 RG3/VLCAP2 ........................................................ 20, 27 RG4/SEG26 ......................................................... 20, 27 RH0/SEG47 ............................................................... 28 RH1/SEG46 ............................................................... 28 RH2/SEG45 ............................................................... 28 RH3/SEG44 ............................................................... 28 RH4/SEG40 ............................................................... 28 RH5/SEG41 ............................................................... 28 RH6/SEG42 ............................................................... 28 RH7/SEG43 ............................................................... 28 RJ0 ............................................................................ 29 RJ1/SEG33 ................................................................ 29 RJ2/SEG34 ................................................................ 29 RJ3/SEG35 ................................................................ 29 RJ4/SEG39 ................................................................ 29 RJ5/SEG38 ................................................................ 29 RJ6/SEG37 ................................................................ 29 RJ7/SEG36 ................................................................ 29 VDD ............................................................................ 29 VDD ............................................................................ 20 VDDCORE/VCAP ..................................................... 29, 20 VSS ............................................................................ 20 VSS ............................................................................ 29 Pinout I/O Descriptions PIC18F6XJ90 ............................................................ 14 PIC18F8XJ90 ............................................................ 21 PIR Registers ................................................................... 104 PLL .................................................................................... 40 ECPLL Oscillator Mode ............................................. 40 HSPLL Oscillator Mode ............................................. 40 POP ................................................................................. 334 POR. See Power-on Reset. 2010 Microchip Technology Inc. PIC18F85J90 FAMILY PORTA Associated Registers ............................................... 117 LATA Register .......................................................... 116 PORTA Register ...................................................... 116 TRISA Register ........................................................ 116 PORTB Associated Registers ............................................... 120 LATB Register .......................................................... 118 PORTB Register ...................................................... 118 RB7:RB4 Interrupt-on-Change Flag (RBIF Bit) ......................................................... 118 TRISB Register ........................................................ 118 PORTC Associated Registers ............................................... 123 LATC Register ......................................................... 121 PORTC Register ...................................................... 121 RC3/SCK/SCL Pin ................................................... 207 TRISC Register ........................................................ 121 PORTD Associated Registers ............................................... 125 LATD Register ......................................................... 124 PORTD Register ...................................................... 124 TRISD Register ........................................................ 124 PORTE Associated Registers ............................................... 127 LATE Register .......................................................... 126 PORTE Register ...................................................... 126 TRISE Register ........................................................ 126 PORTF Associated Registers ............................................... 130 LATF Register .......................................................... 128 PORTF Register ...................................................... 128 TRISF Register ........................................................ 128 PORTG Associated Registers ............................................... 132 LATG Register ......................................................... 131 PORTG Register ...................................................... 131 TRISG Register ........................................................ 131 PORTH Associated Registers ............................................... 134 LATH Register ......................................................... 133 PORTH Register ...................................................... 133 TRISH Register ........................................................ 133 PORTJ Associated Registers ............................................... 136 LATJ Register .......................................................... 135 PORTJ Register ....................................................... 135 TRISJ Register ......................................................... 135 Power-Managed Modes ..................................................... 43 and SPI Operation ................................................... 199 Clock Sources ............................................................ 43 Clock Transitions and Status Indicators ..................... 44 Entering ...................................................................... 43 Exiting Idle and Sleep Modes .................................... 49 By Interrupt ........................................................ 49 By Reset ............................................................ 49 By WDT Time-out .............................................. 49 Without an Oscillator Start-up Delay .................. 49 Idle Modes ................................................................. 47 PRI_IDLE ........................................................... 48 RC_IDLE ............................................................ 49 SEC_IDLE ......................................................... 48 Multiple Sleep Commands ......................................... 44 2010 Microchip Technology Inc. Run Modes ................................................................ 44 PRI_RUN ........................................................... 44 RC_RUN ............................................................ 46 SEC_RUN ......................................................... 44 Selecting .................................................................... 43 Sleep Mode ............................................................... 47 Summary (table) ........................................................ 43 Power-on Reset (POR) ...................................................... 53 Power-up Delays ............................................................... 42 Power-up Timer (PWRT) ............................................. 42, 54 Time-out Sequence ................................................... 54 Prescaler, Capture ........................................................... 156 Prescaler, Timer0 ............................................................ 139 Prescaler, Timer2 ............................................................ 160 PRI_IDLE Mode ................................................................. 48 PRI_RUN Mode ................................................................. 44 Program Counter ............................................................... 65 PCL, PCH and PCU Registers .................................. 65 PCLATH and PCLATU Registers .............................. 65 Program Memory Extended Instruction Set ........................................... 82 Flash Configuration Words ........................................ 64 Hard Memory Vectors ................................................ 64 Instructions ................................................................ 69 Two-Word .......................................................... 69 Interrupt Vector .......................................................... 64 Look-up Tables .......................................................... 67 Memory Maps ............................................................ 63 Hard Vectors and Configuration Words ............. 64 Reset Vector .............................................................. 64 Program Verification and Code Protection ...................... 303 Programming, Device Instructions ................................... 305 Pulse-Width Modulation. See PWM (CCP Module). PUSH ............................................................................... 334 PUSH and POP Instructions .............................................. 66 PUSHL ............................................................................. 350 PWM (CCP Module) Associated Registers ............................................... 161 Duty Cycle ............................................................... 160 Example Frequencies/Resolutions .......................... 160 Period ...................................................................... 159 Setup for PWM Operation ....................................... 161 TMR2 to PR2 Match ................................................ 159 Q Q Clock ............................................................................ 160 R RAM. See Data Memory. RC_IDLE Mode .................................................................. 49 RC_RUN Mode .................................................................. 46 RCALL ............................................................................. 335 RCON Register Bit Status During Initialization .................................... 56 Reader Response ............................................................ 414 Register File ....................................................................... 73 Register File Summary ................................................ 75-78 Registers ADCON0 (A/D Control 0) ......................................... 271 ADCON1 (A/D Control 1) ......................................... 272 ADCON2 (A/D Control 2) ......................................... 273 BAUDCON1 (Baud Rate Control 1) ......................... 238 CCPxCON (CCPx Control, CCP1/CCP2) ................ 153 CMCON (Comparator Control) ................................ 281 CONFIG1H (Configuration 1 High) .......................... 293 CONFIG1L (Configuration 1 Low) ........................... 293 DS39770C-page 409 PIC18F85J90 FAMILY CONFIG2H (Configuration 2 High) .......................... 295 CONFIG2L (Configuration 2 Low) ............................ 294 CONFIG3H (Configuration 3 High) .......................... 295 CVRCON (Comparator Voltage Reference Control) ........................................... 287 DEVID1 (Device ID Register 1) ................................ 296 DEVID2 (Device ID Register 2) ................................ 296 EECON1 (EEPROM Control 1) .................................. 89 INTCON (Interrupt Control) ...................................... 101 INTCON2 (Interrupt Control 2) ................................. 102 INTCON3 (Interrupt Control 3) ................................. 103 IPR1 (Peripheral Interrupt Priority 1) ........................ 110 IPR2 (Peripheral Interrupt Priority 2) ........................ 111 IPR3 (Peripheral Interrupt Priority 3) ........................ 112 LCDCON (LCD Control) ........................................... 164 LCDDATAx (LCD Data) ........................................... 167 LCDPS (LCD Phase) ............................................... 165 LCDREG (LCD Voltage Regulator Control) ............. 169 LCDSEx (LCD Segment Enable) ............................. 166 OSCCON (Oscillator Control) .................................... 36 OSCTUNE (Oscillator Tuning) ................................... 37 PIE1 (Peripheral Interrupt Enable 1) ........................ 107 PIE2 (Peripheral Interrupt Enable 2) ........................ 108 PIE3 (Peripheral Interrupt Enable 3) ........................ 109 PIR1 (Peripheral Interrupt Request (Flag) 1) ........... 104 PIR2 (Peripheral Interrupt Request (Flag) 2) ........... 105 PIR3 (Peripheral Interrupt Request (Flag) 3) ........... 106 RCON (Reset Control) ....................................... 52, 113 RCSTA1 (EUSART Receive Status and Control) .... 237 RCSTA2 (AUSART Receive Status and Control) .... 259 SSPCON1 (MSSP Control 1, I2C Mode) ................. 202 SSPCON1 (MSSP Control 1, SPI Mode) ................. 193 SSPCON2 (MSSP Control 2, I2C Master Mode) ..... 203 SSPCON2 (MSSP Control 2, I2C Slave Mode) ....... 204 SSPSTAT (MSSP Status, I2C Mode) ....................... 201 SSPSTAT (MSSP Status, SPI Mode) ...................... 192 STATUS ..................................................................... 79 STKPTR (Stack Pointer) ............................................ 66 T0CON (Timer0 Control) .......................................... 137 T1CON (Timer1 Control) .......................................... 141 T2CON (Timer2 Control) .......................................... 147 T3CON (Timer3 Control) .......................................... 149 TXSTA1 (EUSART Transmit Status and Control) .......................................... 236 TXSTA2 (AUSART Transmit Status and Control) .......................................... 258 WDTCON (Watchdog Timer Control) ....................... 298 RESET ............................................................................. 335 Reset .................................................................................. 51 Brown-out Reset (BOR) ............................................. 51 MCLR Reset, During Power-Managed Modes ........... 51 MCLR Reset, Normal Operation ................................ 51 Power-on Reset (POR) .............................................. 51 RESET Instruction ..................................................... 51 Stack Full Reset ......................................................... 51 Stack Underflow Reset .............................................. 51 Watchdog Timer (WDT) Reset ................................... 51 Resets .............................................................................. 291 Brown-out Reset (BOR) ........................................... 291 Oscillator Start-up Timer (OST) ............................... 291 Power-on Reset (POR) ............................................ 291 Power-up Timer (PWRT) ......................................... 291 RETFIE ............................................................................ 336 DS39770C-page 410 RETLW ............................................................................ 336 RETURN .......................................................................... 337 Return Address Stack ........................................................ 65 Return Stack Pointer (STKPTR) ........................................ 66 Revision History ............................................................... 399 RLCF ............................................................................... 337 RLNCF ............................................................................. 338 RRCF ............................................................................... 338 RRNCF ............................................................................ 339 S SCK ................................................................................. 191 SDI ................................................................................... 191 SDO ................................................................................. 191 SEC_IDLE Mode ............................................................... 48 SEC_RUN Mode ................................................................ 44 Serial Clock, SCK ............................................................ 191 Serial Data In (SDI) .......................................................... 191 Serial Data Out (SDO) ..................................................... 191 Serial Peripheral Interface. See SPI Mode. SETF ................................................................................ 339 Slave Select (SS) ............................................................. 191 SLEEP ............................................................................. 340 Sleep OSC1 and OSC2 Pin States ...................................... 42 Software Simulator (MPLAB SIM) ................................... 357 Special Event Trigger. See Compare (CCP Module). Special Features of the CPU ........................................... 291 SPI Mode (MSSP) Associated Registers ............................................... 199 Bus Mode Compatibility ........................................... 199 Effects of a Reset .................................................... 199 Enabling SPI I/O ...................................................... 195 Master Mode ............................................................ 196 Operation ................................................................. 194 Operation in Power-Managed Modes ...................... 199 Serial Clock .............................................................. 191 Serial Data In ........................................................... 191 Serial Data Out ........................................................ 191 Slave Mode .............................................................. 197 Slave Select ............................................................. 191 Slave Select Synchronization .................................. 197 SPI Clock ................................................................. 196 Typical Connection .................................................. 195 SS .................................................................................... 191 SSPOV ............................................................................ 225 SSPOV Status Flag ......................................................... 225 SSPSTAT Register R/W Bit ............................................................ 205, 207 Stack Full/Underflow Resets .............................................. 67 SUBFSR .......................................................................... 351 SUBFWB ......................................................................... 340 SUBLW ............................................................................ 341 SUBULNK ........................................................................ 351 SUBWF ............................................................................ 341 SUBWFB ......................................................................... 342 SWAPF ............................................................................ 342 T Table Pointer Operations (table) ........................................ 90 Table Reads/Table Writes ................................................. 67 TBLRD ............................................................................. 343 TBLWT ............................................................................. 344 2010 Microchip Technology Inc. PIC18F85J90 FAMILY Timer0 .............................................................................. 137 Associated Registers ............................................... 139 Clock Source Select (T0CS Bit) ............................... 138 Operation ................................................................. 138 Overflow Interrupt .................................................... 139 Prescaler .................................................................. 139 Switching Assignment ...................................... 139 Prescaler Assignment (PSA Bit) .............................. 139 Prescaler Select (T0PS2:T0PS0 Bits) ..................... 139 Prescaler. See Prescaler, Timer0. Reads and Writes in 16-Bit Mode ............................ 138 Source Edge Select (T0SE Bit) ................................ 138 Timer1 .............................................................................. 141 16-Bit Read/Write Mode ........................................... 143 Associated Registers ............................................... 145 Interrupt .................................................................... 144 Operation ................................................................. 142 Oscillator .......................................................... 141, 143 Layout Considerations ..................................... 144 Oscillator, as Secondary Clock .................................. 37 Overflow Interrupt .................................................... 141 Resetting, Using the CCP Special Event Trigger ................................................... 144 TMR1H Register ...................................................... 141 TMR1L Register ....................................................... 141 Use as a Clock Source ............................................ 143 Use as a Real-Time Clock ....................................... 144 Timer2 .............................................................................. 147 Associated Registers ............................................... 148 Interrupt .................................................................... 148 Operation ................................................................. 147 Output ...................................................................... 148 PR2 Register ............................................................ 159 TMR2 to PR2 Match Interrupt .................................. 159 Timer3 .............................................................................. 149 16-Bit Read/Write Mode ........................................... 151 Associated Registers ............................................... 151 Operation ................................................................. 150 Oscillator .......................................................... 149, 151 Overflow Interrupt ............................................ 149, 151 Special Event Trigger (CCP) .................................... 151 TMR3H Register ...................................................... 149 TMR3L Register ....................................................... 149 Timing Diagrams A/D Conversion ........................................................ 392 Acknowledge Sequence .......................................... 228 Asynchronous Reception ................................. 248, 265 Asynchronous Transmission ............................ 246, 263 Asynchronous Transmission (Back to Back) ......................................... 246, 263 Automatic Baud Rate Calculation ............................ 244 Auto-Wake-up Bit (WUE) During Normal Operation ............................................ 249 Auto-Wake-up Bit (WUE) During Sleep ................... 249 Baud Rate Generator with Clock Arbitration ............ 222 BRG Overflow Sequence ......................................... 244 BRG Reset Due to SDA Arbitration During Start Condition .......................................................... 231 Bus Collision During a Repeated Start Condition (Case 1) ........................................... 232 Bus Collision During a Repeated Start Condition (Case 2) ........................................... 232 Bus Collision During a Start Condition (SCL = 0) ......................................................... 231 2010 Microchip Technology Inc. Bus Collision During a Stop Condition (Case 1) ...... 233 Bus Collision During a Stop Condition (Case 2) ...... 233 Bus Collision During Start Condition (SDA Only) .... 230 Bus Collision for Transmit and Acknowledge .......... 229 Capture/Compare/PWM (CCP1,CCP2) ................... 381 CLKO and I/O .......................................................... 378 Clock Synchronization ............................................. 215 Clock/Instruction Cycle .............................................. 68 EUSART/AUSART Synchronous Receive (Master/Slave) ................................................. 390 EUSART/AUSART Synchronous Transmission (Master/Slave) ................................................. 390 Example SPI Master Mode (CKE = 0) ..................... 382 Example SPI Master Mode (CKE = 1) ..................... 383 Example SPI Slave Mode (CKE = 0) ....................... 384 Example SPI Slave Mode (CKE = 1) ....................... 385 External Clock (All Modes Except PLL) ................... 376 Fail-Safe Clock Monitor ........................................... 302 First Start Bit Timing ................................................ 223 I2C Bus Data ............................................................ 386 I2C Bus Start/Stop Bits ............................................ 386 I2C Master Mode (7 or 10-Bit Transmission) ........... 226 I2C Master Mode (7-Bit Reception) ......................... 227 I2C Slave Mode (10-Bit Reception, SEN = 0, ADMSK = 01001) ............................................ 212 I2C Slave Mode (10-Bit Reception, SEN = 0) .......... 211 I2C Slave Mode (10-Bit Reception, SEN = 1) .......... 217 I2C Slave Mode (10-Bit Transmission) .................... 213 I2C Slave Mode (7-Bit Reception, SEN = 0, ADMSK = 01011) ............................................ 209 I2C Slave Mode (7-Bit Reception, SEN = 0) ............ 208 I2C Slave Mode (7-Bit Reception, SEN = 1) ............ 216 I2C Slave Mode (7-Bit Transmission) ...................... 210 I2C Slave Mode General Call Address Sequence (7 or 10-Bit Address Mode) ............ 218 I2C Stop Condition Receive or Transmit Mode ........ 228 LCD Interrupt in Quarter Duty Cycle Drive .............. 186 LCD Sleep Entry/Exit When SLPEN = 1 or CS1:CS0 = 00 ................................................. 187 MSSP I2C Bus Data ................................................ 388 MSSP I2C Bus Start/Stop Bits ................................. 388 PWM Output ............................................................ 159 Repeated Start Condition ........................................ 224 Reset, Watchdog Timer (WDT), Oscillator Start-up Timer (OST) and Power-up Timer (PWRT) ..... 379 Send Break Character Sequence ............................ 250 Slave Synchronization ............................................. 197 Slow Rise Time (MCLR Tied to VDD, VDD Rise > TPWRT) ............................................ 55 SPI Mode (Master Mode) ........................................ 196 SPI Mode (Slave Mode, CKE = 0) ........................... 198 SPI Mode (Slave Mode, CKE = 1) ........................... 198 Synchronous Reception (Master Mode, SREN) ............................. 253, 268 Synchronous Transmission ............................. 251, 266 Synchronous Transmission (Through TXEN) ...................................... 252, 267 Time-out Sequence on Power-up (MCLR Not Tied to VDD), Case 1 ...................... 54 Time-out Sequence on Power-up (MCLR Not Tied to VDD), Case 2 ...................... 55 Time-out Sequence on Power-up (MCLR Tied to VDD, VDD Rise TPWRT) .............. 54 Timer0 and Timer1 External Clock .......................... 380 Transition for Entry to Idle Mode ............................... 48 DS39770C-page 411 PIC18F85J90 FAMILY Transition for Entry to SEC_RUN Mode .................... 45 Transition for Entry to Sleep Mode ............................ 47 Transition for Two-Speed Start-up (INTRC to HSPLL) ........................................... 300 Transition for Wake From Idle to Run Mode .............. 48 Transition for Wake From Sleep (HSPLL) ................. 47 Transition From RC_RUN Mode to PRI_RUN Mode ................................................. 46 Transition From SEC_RUN Mode to PRI_RUN Mode (HSPLL) .................................. 45 Transition to RC_RUN Mode ..................................... 46 Type-A in 1/2 MUX, 1/2 Bias Drive .......................... 176 Type-A in 1/2 MUX, 1/3 Bias Drive .......................... 178 Type-A in 1/3 MUX, 1/2 Bias Drive .......................... 180 Type-A in 1/3 MUX, 1/3 Bias Drive .......................... 182 Type-A in 1/4 MUX, 1/3 Bias Drive .......................... 184 Type-A/Type-B in Static Drive .................................. 175 Type-B in 1/2 MUX, 1/2 Bias Drive .......................... 177 Type-B in 1/2 MUX, 1/3 Bias Drive .......................... 179 Type-B in 1/3 MUX, 1/2 Bias Drive .......................... 181 Type-B in 1/3 MUX, 1/3 Bias Drive .......................... 183 Type-B in 1/4 MUX, 1/3 Bias Drive .......................... 185 Timing Diagrams and Specifications Capture/Compare/PWM Requirements (CCP1, CCP2) ................................................. 381 CLKO and I/O Requirements ................................... 378 EUSART/AUSART Synchronous Receive Requirements ................................................... 390 EUSART/AUSART Synchronous Transmission Requirements ................................................... 390 Example SPI Mode Requirements (Master Mode, CKE = 0) ................................. 382 Example SPI Mode Requirements (Master Mode, CKE = 1) ................................. 383 Example SPI Mode Requirements (Slave Mode, CKE = 0) .................................... 384 Example SPI Slave Mode Requirements (CKE = 1) .................................. 385 External Clock Requirements .................................. 376 I2C Bus Data Requirements (Slave Mode) .............. 387 I2C Bus Start/Stop Bits Requirements (Slave Mode) .................................................... 386 Internal RC Accuracy ............................................... 377 MSSP I2C Bus Data Requirements ......................... 389 MSSP I2C Bus Start/Stop Bits Requirements .......... 388 DS39770C-page 412 PLL Clock ................................................................ 377 Reset, Watchdog Timer, Oscillator Start-up Timer, Power-up Timer and Brown-out Reset Requirements ........................................ 379 Timer0 and Timer1 External Clock Requirements .................................................. 380 Top-of-Stack Access .......................................................... 65 TSTFSZ ........................................................................... 345 Two-Speed Start-up ................................................. 291, 300 Two-Word Instructions Example Cases .......................................................... 69 V VDDCORE/VCAP Pin .......................................................... 299 Voltage Reference Specifications .................................... 373 Voltage Regulator (On-Chip) ........................................... 299 Brown-out Reset (BOR) ........................................... 300 Low-Voltage Detection (LVD) .................................. 299 Operation in Sleep Mode ......................................... 300 Power-up Requirements .......................................... 300 W Watchdog Timer (WDT) ........................................... 291, 297 Associated Registers ............................................... 298 Control Register ....................................................... 297 During Oscillator Failure .......................................... 301 Programming Considerations .................................. 297 WCOL ...................................................... 223, 224, 225, 228 WCOL Status Flag ................................... 223, 224, 225, 228 WWW Address ................................................................ 413 WWW, On-Line Support ...................................................... 7 X XORLW ............................................................................ 345 XORWF ........................................................................... 346 2010 Microchip Technology Inc. PIC18F85J90 FAMILY THE MICROCHIP WEB SITE CUSTOMER SUPPORT Microchip provides online support via our WWW site at www.microchip.com. This web site is used as a means to make files and information easily available to customers. Accessible by using your favorite Internet browser, the web site contains the following information: Users of Microchip products can receive assistance through several channels: * Product Support - Data sheets and errata, application notes and sample programs, design resources, user's guides and hardware support documents, latest software releases and archived software * General Technical Support - Frequently Asked Questions (FAQ), technical support requests, online discussion groups, Microchip consultant program member listing * Business of Microchip - Product selector and ordering guides, latest Microchip press releases, listing of seminars and events, listings of Microchip sales offices, distributors and factory representatives * * * * Distributor or Representative Local Sales Office Field Application Engineer (FAE) Technical Support Customers should contact their distributor, representative or field application engineer (FAE) for support. Local sales offices are also available to help customers. A listing of sales offices and locations is included in the back of this document. Technical support is available through the web site at: http://support.microchip.com CUSTOMER CHANGE NOTIFICATION SERVICE Microchip's customer notification service helps keep customers current on Microchip products. Subscribers will receive e-mail notification whenever there are changes, updates, revisions or errata related to a specified product family or development tool of interest. To register, access the Microchip web site at www.microchip.com, click on Customer Change Notification and follow the registration instructions. 2010 Microchip Technology Inc. DS39770C-page 413 PIC18F85J90 FAMILY READER RESPONSE It is our intention to provide you with the best documentation possible to ensure successful use of your Microchip product. If you wish to provide your comments on organization, clarity, subject matter, and ways in which our documentation can better serve you, please FAX your comments to the Technical Publications Manager at (480) 792-4150. Please list the following information, and use this outline to provide us with your comments about this document. To: Technical Publications Manager RE: Reader Response Total Pages Sent ________ From: Name Company Address City / State / ZIP / Country Telephone: (_______) _________ - _________ FAX: (______) _________ - _________ Application (optional): Would you like a reply? Y N Device: PIC18F85J90 Family Literature Number: DS39770C Questions: 1. What are the best features of this document? 2. How does this document meet your hardware and software development needs? 3. Do you find the organization of this document easy to follow? If not, why? 4. What additions to the document do you think would enhance the structure and subject? 5. What deletions from the document could be made without affecting the overall usefulness? 6. Is there any incorrect or misleading information (what and where)? 7. How would you improve this document? DS39770C-page 414 2010 Microchip Technology Inc. PIC18F85J90 FAMILY PRODUCT IDENTIFICATION SYSTEM To order or obtain information, e.g., on pricing or delivery, refer to the factory or the listed sales office. PART NO. X /XX XXX Device Temperature Range Package Pattern Device PIC18F63J90/64J90/65J90(1), PIC18F83J90/84J90/85J90(1), PIC18F63J90/64J90/65J90T(2), PIC18F83J90/84J90/85J90T(2) Temperature Range I = -40C to +85C (Industrial) Package PT = TQFP (Thin Quad Flatpack) Pattern QTP, SQTP, Code or Special Requirements (blank otherwise) 2010 Microchip Technology Inc. Examples: a) b) PIC18F85J90-I/PT 301 = Industrial temp., TQFP package, QTP pattern #301. PIC18F63J90T-I/PT = Tape and reel, Industrial temp., TQFP package. Note 1: F 2: T = Standard Voltage Range = in tape and reel DS39770C-page 415 WORLDWIDE SALES AND SERVICE AMERICAS ASIA/PACIFIC ASIA/PACIFIC EUROPE Corporate Office 2355 West Chandler Blvd. Chandler, AZ 85224-6199 Tel: 480-792-7200 Fax: 480-792-7277 Technical Support: http://support.microchip.com Web Address: www.microchip.com Asia Pacific Office Suites 3707-14, 37th Floor Tower 6, The Gateway Harbour City, Kowloon Hong Kong Tel: 852-2401-1200 Fax: 852-2401-3431 India - Bangalore Tel: 91-80-3090-4444 Fax: 91-80-3090-4123 India - New Delhi Tel: 91-11-4160-8631 Fax: 91-11-4160-8632 Austria - Wels Tel: 43-7242-2244-39 Fax: 43-7242-2244-393 Denmark - Copenhagen Tel: 45-4450-2828 Fax: 45-4485-2829 India - Pune Tel: 91-20-2566-1512 Fax: 91-20-2566-1513 France - Paris Tel: 33-1-69-53-63-20 Fax: 33-1-69-30-90-79 Japan - Yokohama Tel: 81-45-471- 6166 Fax: 81-45-471-6122 Germany - Munich Tel: 49-89-627-144-0 Fax: 49-89-627-144-44 Atlanta Duluth, GA Tel: 678-957-9614 Fax: 678-957-1455 Boston Westborough, MA Tel: 774-760-0087 Fax: 774-760-0088 Chicago Itasca, IL Tel: 630-285-0071 Fax: 630-285-0075 Cleveland Independence, OH Tel: 216-447-0464 Fax: 216-447-0643 Dallas Addison, TX Tel: 972-818-7423 Fax: 972-818-2924 Detroit Farmington Hills, MI Tel: 248-538-2250 Fax: 248-538-2260 Kokomo Kokomo, IN Tel: 765-864-8360 Fax: 765-864-8387 Los Angeles Mission Viejo, CA Tel: 949-462-9523 Fax: 949-462-9608 Santa Clara Santa Clara, CA Tel: 408-961-6444 Fax: 408-961-6445 Toronto Mississauga, Ontario, Canada Tel: 905-673-0699 Fax: 905-673-6509 Australia - Sydney Tel: 61-2-9868-6733 Fax: 61-2-9868-6755 China - Beijing Tel: 86-10-8528-2100 Fax: 86-10-8528-2104 China - Chengdu Tel: 86-28-8665-5511 Fax: 86-28-8665-7889 Korea - Daegu Tel: 82-53-744-4301 Fax: 82-53-744-4302 China - Chongqing Tel: 86-23-8980-9588 Fax: 86-23-8980-9500 Korea - Seoul Tel: 82-2-554-7200 Fax: 82-2-558-5932 or 82-2-558-5934 China - Hong Kong SAR Tel: 852-2401-1200 Fax: 852-2401-3431 Malaysia - Kuala Lumpur Tel: 60-3-6201-9857 Fax: 60-3-6201-9859 China - Nanjing Tel: 86-25-8473-2460 Fax: 86-25-8473-2470 Malaysia - Penang Tel: 60-4-227-8870 Fax: 60-4-227-4068 China - Qingdao Tel: 86-532-8502-7355 Fax: 86-532-8502-7205 Philippines - Manila Tel: 63-2-634-9065 Fax: 63-2-634-9069 China - Shanghai Tel: 86-21-5407-5533 Fax: 86-21-5407-5066 Singapore Tel: 65-6334-8870 Fax: 65-6334-8850 China - Shenyang Tel: 86-24-2334-2829 Fax: 86-24-2334-2393 Taiwan - Hsin Chu Tel: 886-3-6578-300 Fax: 886-3-6578-370 China - Shenzhen Tel: 86-755-8203-2660 Fax: 86-755-8203-1760 Taiwan - Kaohsiung Tel: 886-7-536-4818 Fax: 886-7-536-4803 China - Wuhan Tel: 86-27-5980-5300 Fax: 86-27-5980-5118 Taiwan - Taipei Tel: 886-2-2500-6610 Fax: 886-2-2508-0102 China - Xian Tel: 86-29-8833-7252 Fax: 86-29-8833-7256 Thailand - Bangkok Tel: 66-2-694-1351 Fax: 66-2-694-1350 Italy - Milan Tel: 39-0331-742611 Fax: 39-0331-466781 Netherlands - Drunen Tel: 31-416-690399 Fax: 31-416-690340 Spain - Madrid Tel: 34-91-708-08-90 Fax: 34-91-708-08-91 UK - Wokingham Tel: 44-118-921-5869 Fax: 44-118-921-5820 China - Xiamen Tel: 86-592-2388138 Fax: 86-592-2388130 China - Zhuhai Tel: 86-756-3210040 Fax: 86-756-3210049 01/05/10 DS39770C-page 416 2010 Microchip Technology Inc.