Si106x/108x Ultra Low Power, 64/32 kB, 10-Bit ADC MCU with Integrated 240-960 MHz EZRadioPRO(R) Transceiver Ultra-low power 8051 C Core - 25 MHz, single-cycle 8051 compatible CPU - 25 MIPS peak throughput with 25 MHz clock - Industry's lowest active and sleep currents - 160 A/MHz: active mode - 10 nA sleep with brownout detectors disabled - 50 nA sleep with brownout detectors enabled - 600 nA sleep with internal RTC - 2 s wake-up time - On-chip debug - Memory - Up to 64 kB of flash and 4 kB of RAM System Peripherals - Supply voltage: 1.8 to 3.6 V - 0.9-3.6 V operation with built-in dc-dc converter - Brownout detectors cover sleep and active modes - Low battery detector - Low BOM count - 5x6 36-pin QFN package - 10-bit analog-to-digital converter - Temperature sensor - Dual comparators - 11 general purpose I/O - UART, SPI, I2C - Four general purpose 16-bit counter/timers - Precision internal oscillators - 24.5 MHz with 2% accuracy - Low power 20 MHz internal oscillator - External oscillator: crystal, RC, C, CMOS clock - RTC: 32.768 kHz crystal or self-oscillate Applications Transceiver Features (Si1060) - Data rate up to 1 Mbps 142-1050 MHz frequency range On-chip crystal tuning -126 dBm receive sensitivity @ 500 bps, GFSK Modulation: OOK, (G)FSK, and 4(G)FSK Up to +20 dBm output power Low power consumption CIP-51 8051 Controller Core Power On Reset/PMU Wake RST/C2CK Debug / Programming Hardware - Home automation Home security Remote control Garage door openers Remote keyless Entry Home health care Smart metering Building Lighting control Building HVAC control Fire and Security monitoring Security and Access control Telemetry Analog Peripherals Flash Program Memory Reset - 10/13 mA RX - 18 mA TX at +10 dBm - 30 nA shutdown, 50 nA standby - Fast wake and hop times Excellent selectivity performance - 60 dB adjacent channel - 73 dB blocking at 1 MHz Antenna diversity and T/R switch control Highly configurable packet handler TX and RX 64 byte FIFOs Auto frequency control (AFC) Automatic gain control (AGC) IEEE 802.15.4g compliant Internal External VREF VREF A M U X 10-bit 300ksps ADC SRAM VDD VREF Temp Sensor GND C2D VDD/DC+ Analog Power VREG Digital Power DC/DC Converter GND P0.2/XTAL1 P0.3/XTAL2 XTAL3 XTAL4 Precision 24.5 MHz Oscillator Low Power 20 MHz Oscillator + - + - SFR Bus PA TX AGC RXp RXn LNA Mixer PGA Comparators Digital Peripherals Transceiver Control Interface ADC Modem FIFO Packet Handler Digital Logic 4 GPIO UART External Oscillator Circuit Timers 0, 1, 2, 3 SmaRTClock Oscillator PCA/ WDT System Clock Configuration Rev. 1.0 2/13 CP1, CP1A SYSCLK GND/DC- VBAT CP0, CP0A CRC Engine RF XCVR XIN XOUT OSC Priority Crossbar Decoder LDO POR SMBus SPI 0 Copyright (c) 2013 by Silicon Laboratories Port I/O Config VDD 11 ANALOG & DIGITAL I/O Si106x/108x 2 Rev. 1.0 Si106x/108x Table of Contents 1. System Overview ..................................................................................................... 15 1.1. Typical Connection Diagram ............................................................................. 17 1.2. CIP-51TM Microcontroller Core .......................................................................... 18 1.3. Port Input/Output ............................................................................................... 19 1.4. Serial Ports ........................................................................................................ 20 1.5. Programmable Counter Array............................................................................ 20 1.6. 10-bit SAR ADC with 16-bit Auto-Averaging Accumulator and Autonomous Low Power Burst Mode............................................................................................... 21 1.7. Comparators...................................................................................................... 22 2. Si106x/108x Ordering Information.......................................................................... 24 3. Pinout and Package Definitions ............................................................................. 25 4. Electrical Characteristics ........................................................................................ 42 4.1. Absolute Maximum Specifications..................................................................... 42 4.2. MCU Electrical Characteristics .......................................................................... 43 4.3. Radio Electrical Characteristics......................................................................... 67 5. 10-Bit SAR ADC with 16-bit Auto-Averaging Accumulator and Autonomous Low Power Burst Mode ....................................................................................................... 78 5.1. Output Code Formatting .................................................................................... 78 5.2. Modes of Operation ........................................................................................... 80 5.3. 8-Bit Mode ......................................................................................................... 85 5.4. Programmable Window Detector....................................................................... 92 5.5. ADC0 Analog Multiplexer .................................................................................. 95 5.6. Temperature Sensor.......................................................................................... 97 5.7. Voltage and Ground Reference Options ......................................................... 100 5.8. External Voltage References........................................................................... 101 5.9. Internal Voltage References ............................................................................ 101 5.10. Analog Ground Reference............................................................................. 101 5.11. Temperature Sensor Enable ......................................................................... 101 5.12. Voltage Reference Electrical Specifications .................................................. 102 6. Comparators........................................................................................................... 103 6.1. Comparator Inputs........................................................................................... 103 6.2. Comparator Outputs ........................................................................................ 104 6.3. Comparator Response Time ........................................................................... 105 6.4. Comparator Hysteresis.................................................................................... 105 6.5. Comparator Register Descriptions .................................................................. 106 6.6. Comparator0 and Comparator1 Analog Multiplexers ...................................... 110 7. CIP-51 Microcontroller........................................................................................... 113 7.1. Performance .................................................................................................... 113 7.2. Programming and Debugging Support ............................................................ 114 7.3. Instruction Set.................................................................................................. 114 7.4. CIP-51 Register Descriptions .......................................................................... 119 8. Memory Organization ............................................................................................ 122 8.1. Program Memory............................................................................................. 124 Rev. 1.0 3 Si106x/108x 8.2. Data Memory ................................................................................................... 125 9. On-Chip XRAM ....................................................................................................... 127 9.1. Accessing XRAM............................................................................................. 127 9.2. Special Function Registers.............................................................................. 128 10. Special Function Registers................................................................................. 129 10.1. SFR Paging ................................................................................................... 130 11. Interrupt Handler.................................................................................................. 137 11.1. Enabling Interrupt Sources ............................................................................ 137 11.2. MCU Interrupt Sources and Vectors.............................................................. 137 11.3. Interrupt Priorities .......................................................................................... 138 11.4. Interrupt Latency............................................................................................ 138 11.5. Interrupt Register Descriptions ...................................................................... 140 11.6. External Interrupts INT0 and INT1................................................................. 147 12. Flash Memory....................................................................................................... 149 12.1. Programming the Flash Memory ................................................................... 149 12.2. Non-Volatile Data Storage............................................................................. 151 12.3. Security Options ............................................................................................ 151 12.4. Determining the Device Part Number at Run Time ....................................... 154 12.5. Flash Write and Erase Guidelines ................................................................. 154 12.6. Minimizing Flash Read Current ..................................................................... 156 13. Power Management ............................................................................................. 160 13.1. Normal Mode ................................................................................................. 161 13.2. Idle Mode....................................................................................................... 162 13.3. Stop Mode ..................................................................................................... 162 13.4. Suspend Mode .............................................................................................. 163 13.5. Sleep Mode ................................................................................................... 163 13.6. Configuring Wakeup Sources........................................................................ 164 13.7. Determining the Event that Caused the Last Wakeup................................... 164 13.8. Power Management Specifications ............................................................... 166 14. Cyclic Redundancy Check Unit (CRC0)............................................................. 167 14.1. 16-bit CRC Algorithm..................................................................................... 167 14.2. 32-bit CRC Algorithm..................................................................................... 169 14.3. Preparing for a CRC Calculation ................................................................... 170 14.4. Performing a CRC Calculation ...................................................................... 170 14.5. Accessing the CRC0 Result .......................................................................... 170 14.6. CRC0 Bit Reverse Feature............................................................................ 174 15. On-Chip DC-DC Converter (DC0)........................................................................ 175 15.1. Startup Behavior............................................................................................ 176 15.2. High Power Applications................................................................................ 177 15.3. Pulse Skipping Mode..................................................................................... 177 15.4. Enabling the DC-DC Converter ..................................................................... 177 15.5. Minimizing Power Supply Noise .................................................................... 179 15.6. Selecting the Optimum Switch Size............................................................... 179 15.7. DC-DC Converter Clocking Options .............................................................. 179 15.8. DC-DC Converter Behavior in Sleep Mode ................................................... 180 4 Rev. 1.0 Si106x/108x 15.9. DC-DC Converter Register Descriptions ....................................................... 181 15.10. DC-DC Converter Specifications ................................................................. 183 16. Voltage Regulator (VREG0)................................................................................. 184 16.1. Voltage Regulator Electrical Specifications ................................................... 184 17. Reset Sources ...................................................................................................... 185 17.1. MCU Power-On (VBAT Supply Monitor) Reset ............................................. 186 17.2. Power-Fail (VDD_MCU Supply Monitor) Reset............................................. 187 17.3. External Reset ............................................................................................... 189 17.4. Missing Clock Detector Reset ....................................................................... 189 17.5. Comparator0 Reset ....................................................................................... 190 17.6. PCA Watchdog Timer Reset ......................................................................... 190 17.7. Flash Error Reset .......................................................................................... 190 17.8. SmaRTClock (Real Time Clock) Reset ......................................................... 190 17.9. Software Reset .............................................................................................. 190 18. Clocking Sources................................................................................................. 192 18.1. Programmable Precision Internal Oscillator .................................................. 193 18.2. Low Power Internal Oscillator........................................................................ 193 18.3. External Oscillator Drive Circuit..................................................................... 193 18.4. Special Function Registers for Selecting and Configuring the System Clock 197 19. SmaRTClock (Real Time Clock).......................................................................... 200 19.1. SmaRTClock Interface .................................................................................. 200 19.2. SmaRTClock Clocking Sources .................................................................... 207 19.3. SmaRTClock Timer and Alarm Function ....................................................... 211 20. Si106x/108xPort Input/Output............................................................................. 217 20.1. Port I/O Modes of Operation.......................................................................... 218 20.2. Assigning Port I/O Pins to Analog and Digital Functions............................... 219 20.3. Priority Crossbar Decoder ............................................................................. 221 20.4. Port Match ..................................................................................................... 226 20.5. Special Function Registers for Accessing and Configuring Port I/O ............. 229 21. Controller Interface.............................................................................................. 238 21.1. Serial Interface (SPI1) ................................................................................... 238 21.2. Fast Response Registers (Si1060/61/62/63 and Si1080/81/82/83) .............. 241 21.3. Operating Modes and Timing ........................................................................ 241 21.4. Application Programming Interface (API) ...................................................... 246 21.5. GPIO .......................................................................................................... 247 22. Radio 142-1050 MHz Transceiver Functional Description .............................. 248 23. Modulation and Hardware Configuration Options............................................ 249 23.1. Modulation Types .......................................................................................... 249 23.2. Hardware Configuration Options ................................................................... 249 23.3. Preamble Length ........................................................................................... 250 24. Internal Functional Blocks .................................................................................. 252 24.1. RX Chain ....................................................................................................... 252 24.2. RX Modem..................................................................................................... 253 24.3. Synthesizer.................................................................................................... 255 24.4. Transmitter (TX) ............................................................................................ 258 Rev. 1.0 5 Si106x/108x 24.5. Crystal Oscillator ........................................................................................... 261 25. Data Handling and Packet Handler .................................................................... 262 25.1. RX and TX FIFOs .......................................................................................... 262 25.2. Packet Handler .............................................................................................. 262 26. RX Modem Configuration.................................................................................... 263 27. Auxiliary Blocks ................................................................................................... 263 27.1. Wake-Up Timer and 32 kHz Clock Source.................................................... 263 27.2. Low Duty Cycle Mode (Auto RX Wake-Up)................................................... 265 27.3. Antenna Diversity (Si1060-Si1063, Si1080-Si1083) ..................................... 266 28. SMBus................................................................................................................... 267 28.1. Supporting Documents .................................................................................. 268 28.2. SMBus Configuration..................................................................................... 268 28.3. SMBus Operation .......................................................................................... 268 28.4. Using the SMBus........................................................................................... 270 28.5. SMBus Transfer Modes................................................................................. 282 28.6. SMBus Status Decoding................................................................................ 285 29. UART0 ................................................................................................................... 290 29.1. Enhanced Baud Rate Generation.................................................................. 291 29.2. Operational Modes ........................................................................................ 292 29.3. Multiprocessor Communications ................................................................... 293 30. Enhanced Serial Peripheral Interface (SPI0) ..................................................... 298 30.1. Signal Descriptions........................................................................................ 299 30.2. SPI0 Master Mode Operation ........................................................................ 299 30.3. SPI0 Slave Mode Operation .......................................................................... 301 30.4. SPI0 Interrupt Sources .................................................................................. 302 30.5. Serial Clock Phase and Polarity .................................................................... 303 30.6. SPI Special Function Registers ..................................................................... 304 31. Timers ................................................................................................................... 311 31.1. Timer 0 and Timer 1 ...................................................................................... 313 31.2. Timer 2 .......................................................................................................... 321 31.3. Timer 3 .......................................................................................................... 327 32. Si106x/108xSi106x/108x Programmable Counter Array................................... 333 32.1. PCA Counter/Timer ....................................................................................... 334 32.2. PCA0 Interrupt Sources................................................................................. 335 32.3. Capture/Compare Modules ........................................................................... 336 32.4. Watchdog Timer Mode .................................................................................. 344 32.5. Register Descriptions for PCA0..................................................................... 346 33. Device Specific Behavior .................................................................................... 352 33.1. Device Identification ...................................................................................... 352 34. C2 Interface .......................................................................................................... 353 34.1. C2 Interface Registers................................................................................... 353 34.2. C2 Pin Sharing .............................................................................................. 356 Document Change List.............................................................................................. 357 Contact Information................................................................................................... 358 6 Rev. 1.0 Si106x/108x List of Figures Figure 1.1. Si106x/Si108x Block Diagram ............................................................... 16 Figure 1.2. Si106x/108x RX/TX Direct-Tie Application Example ............................. 17 Figure 1.3. Si106x/108x Antenna Diversity Application Example ............................ 17 Figure 1.4. Port I/O Functional Block Diagram ........................................................ 19 Figure 1.5. PCA Block Diagram ............................................................................... 20 Figure 1.6. ADC0 Functional Block Diagram ........................................................... 21 Figure 1.7. ADC0 Multiplexer Block Diagram .......................................................... 22 Figure 1.8. Comparator 0 Functional Block Diagram .............................................. 23 Figure 1.9. Comparator 1 Functional Block Diagram .............................................. 23 Figure 3.1. Si1060/1, Si1080/1-A-GM Pinout Diagram (Top View) ......................... 34 Figure 3.2. Si1062/3, Si1082/3-A-GM Pinout Diagram (Top View) ......................... 35 Figure 3.3. Si1064/5, Si1084/5-A-GM Pinout Diagram (Top View) ......................... 36 Figure 3.4. QFN-36 Package Drawing .................................................................... 37 Figure 3.5. QFN-36 PCB Land Pattern Dimensions ................................................ 39 Figure 3.6. QFN-36 PCB Stencil and Via Placement .............................................. 41 Figure 4.1. Active Mode Current (External CMOS Clock) ....................................... 46 Figure 4.2. Idle Mode Current (External CMOS Clock) ........................................... 47 Figure 4.3. Typical DC-DC Converter Efficiency (High Current, VDD/DC+ = 2 V ... 48 Figure 4.4. Typical DC-DC Converter Efficiency (High Current, VDD/DC+ = 3 V) .. 49 Figure 4.5. Typical DC-DC Converter Efficiency (Low Current, VDD/DC+ = 2 V) ... 50 Figure 4.6. Typical One-Cell Suspend Mode Current .............................................. 51 Figure 4.7. Typical VOH Curves, 1.8-3.6 V ............................................................ 53 Figure 4.8. Typical VOH Curves, 0.9-1.8 V ............................................................ 54 Figure 4.9. Typical VOL Curves, 1.8-3.6 V ............................................................. 55 Figure 4.10. Typical VOL Curves, 0.9-1.8 V ........................................................... 56 Figure 5.1. ADC0 Functional Block Diagram ........................................................... 78 Figure 5.2. 10-Bit ADC Track and Conversion Example Timing (BURSTEN = 0) ... 81 Figure 5.3. Burst Mode Tracking Example with Repeat Count Set to 4 .................. 83 Figure 5.4. ADC0 Equivalent Input Circuits ............................................................. 84 Figure 5.5. ADC Window Compare Example: Right-Justified Single-Ended Data .. 94 Figure 5.6. ADC Window Compare Example: Left-Justified Single-Ended Data ..... 94 Figure 5.7. ADC0 Multiplexer Block Diagram .......................................................... 95 Figure 5.8. Temperature Sensor Transfer Function ................................................ 97 Figure 5.9. Temperature Sensor Error with 1-Point Calibration (VREF = 1.68 V) .... 98 Figure 5.10. Voltage Reference Functional Block Diagram ................................... 100 Figure 6.1. Comparator 0 Functional Block Diagram ............................................ 103 Figure 6.2. Comparator 1 Functional Block Diagram ............................................ 104 Figure 6.3. Comparator Hysteresis Plot ................................................................ 105 Figure 6.4. CPn Multiplexer Block Diagram ........................................................... 110 Figure 7.1. CIP-51 Block Diagram ......................................................................... 113 Figure 8.1. Si106x Memory Map ........................................................................... 122 Figure 8.2. Si108x Memory Map ........................................................................... 123 Figure 8.3. Si106x Flash Program Memory Map ................................................... 124 Rev. 1.0 7 Si106x/108x Figure 8.4. Si108x Flash Program Memory Map ................................................... 124 Figure 12.1. Si106x Flash Program Memory Map ................................................. 151 Figure 12.2. Si108x Flash Program Memory Map ................................................. 152 Figure 13.1. Si106x/108x Power Distribution ........................................................ 161 Figure 14.1. CRC0 Block Diagram ........................................................................ 167 Figure 14.2. Bit Reverse Register ......................................................................... 174 Figure 15.1. DC-DC Converter Block Diagram ...................................................... 175 Figure 15.2. DC-DC Converter Configuration Options .......................................... 178 Figure 17.1. Reset Sources ................................................................................... 185 Figure 17.2. Power-Fail Reset Timing Diagram .................................................... 186 Figure 17.3. Power-Fail Reset Timing Diagram .................................................... 187 Figure 18.1. Clocking Sources Block Diagram ...................................................... 192 Figure 18.2. 25 MHz External Crystal Example ..................................................... 194 Figure 19.1. SmaRTClock Block Diagram ............................................................. 200 Figure 19.2. Interpreting Oscillation Robustness (Duty Cycle) Test Results ......... 209 Figure 20.1. Port I/O Functional Block Diagram .................................................... 217 Figure 20.2. Port I/O Cell Block Diagram .............................................................. 218 Figure 20.3. Crossbar Priority Decoder with No Pins Skipped .............................. 222 Figure 20.4. Crossbar Priority Decoder with Crystal Pins Skipped ....................... 223 Figure 21.1. SPI Write Command .......................................................................... 239 Figure 21.2. SPI Read Command--Check CTS Value ......................................... 239 Figure 21.3. SPI Read Command--Clock Out Read Data .................................... 240 Figure 21.4. State Machine Diagram ..................................................................... 241 Figure 21.5. POR Timing Diagram ........................................................................ 243 Figure 21.6. Start_TX Commands and Timing ...................................................... 245 Figure 24.1. RX Architecture vs. Data Rate .......................................................... 253 Figure 24.2. +20 dBm TX Power vs. PA_PWR_LVL ............................................. 259 Figure 24.3. +20 dBm TX Power vs. VDD ............................................................. 260 Figure 24.4. +20 dBm TX Power vs. Temp ........................................................... 260 Figure 24.5. Capacitor Bank Frequency Offset Characteristics ............................ 261 Figure 25.1. TX and RX FIFOs .............................................................................. 262 Figure 25.2. Packet Handler Structure .................................................................. 262 Figure 27.1. RX and TX LDC Sequences .............................................................. 265 Figure 27.2. Low Duty Cycle Mode for RX ............................................................ 265 Figure 28.1. SMBus Block Diagram ...................................................................... 267 Figure 28.2. Typical SMBus Configuration ............................................................ 268 Figure 28.3. SMBus Transaction ........................................................................... 269 Figure 28.4. Typical SMBus SCL Generation ........................................................ 271 Figure 28.5. Typical Master Write Sequence ........................................................ 282 Figure 28.6. Typical Master Read Sequence ........................................................ 283 Figure 28.7. Typical Slave Write Sequence .......................................................... 284 Figure 28.8. Typical Slave Read Sequence .......................................................... 285 Figure 29.1. UART0 Block Diagram ...................................................................... 290 Figure 29.2. UART0 Baud Rate Logic ................................................................... 291 Figure 29.3. UART Interconnect Diagram ............................................................. 292 8 Rev. 1.0 Si106x/108x Figure 29.4. 8-Bit UART Timing Diagram .............................................................. 292 Figure 29.5. 9-Bit UART Timing Diagram .............................................................. 293 Figure 29.6. UART Multi-Processor Mode Interconnect Diagram ......................... 294 Figure 30.1. SPI Block Diagram ............................................................................ 298 Figure 30.2. Multiple-Master Mode Connection Diagram ...................................... 300 Figure 30.3. 3-Wire Single Master and Slave Mode Connection Diagram ............ 300 Figure 30.4. 4-Wire Single Master and Slave Mode Connection Diagram ............ 301 Figure 30.5. Master Mode Data/Clock Timing ....................................................... 303 Figure 30.6. Slave Mode Data/Clock Timing (CKPHA = 0) ................................... 304 Figure 30.7. Slave Mode Data/Clock Timing (CKPHA = 1) ................................... 304 Figure 30.8. SPI Master Timing (CKPHA = 0) ....................................................... 308 Figure 30.9. SPI Master Timing (CKPHA = 1) ....................................................... 308 Figure 30.10. SPI Slave Timing (CKPHA = 0) ....................................................... 309 Figure 30.11. SPI Slave Timing (CKPHA = 1) ....................................................... 309 Figure 31.1. T0 Mode 0 Block Diagram ................................................................. 314 Figure 31.2. T0 Mode 2 Block Diagram ................................................................. 315 Figure 31.3. T0 Mode 3 Block Diagram ................................................................. 316 Figure 31.4. Timer 2 16-Bit Mode Block Diagram ................................................. 321 Figure 31.5. Timer 2 8-Bit Mode Block Diagram ................................................... 322 Figure 31.6. Timer 2 Capture Mode Block Diagram .............................................. 323 Figure 31.7. Timer 3 16-Bit Mode Block Diagram ................................................. 327 Figure 31.8. Timer 3 8-Bit Mode Block Diagram. .................................................. 328 Figure 31.9. Timer 3 Capture Mode Block Diagram .............................................. 329 Figure 32.1. PCA Block Diagram ........................................................................... 333 Figure 32.2. PCA Counter/Timer Block Diagram ................................................... 334 Figure 32.3. PCA Interrupt Block Diagram ............................................................ 335 Figure 32.4. PCA Capture Mode Diagram ............................................................. 337 Figure 32.5. PCA Software Timer Mode Diagram ................................................. 338 Figure 32.6. PCA High-Speed Output Mode Diagram ........................................... 339 Figure 32.7. PCA Frequency Output Mode ........................................................... 340 Figure 32.8. PCA 8-Bit PWM Mode Diagram ........................................................ 341 Figure 32.9. PCA 9, 10 and 11-Bit PWM Mode Diagram ...................................... 342 Figure 32.10. PCA 16-Bit PWM Mode ................................................................... 343 Figure 32.11. PCA Module 5 with Watchdog Timer Enabled ................................ 344 Figure 33.1. Si106x Revision Information .............................................................. 352 Figure 34.1. Typical C2 Pin Sharing ...................................................................... 356 Rev. 1.0 9 Si106x/108x List of Tables Table 2.1. Orderable Part Number .......................................................................... 24 Table 3.1. Si1060/Si1061/Si1080/Si1081 Pin Definitions ........................................ 25 Table 3.2. Si1062/Si1063/Si1082/Si1083 Pin Definitions ........................................ 28 Table 3.3. Si1064/Si1065/Si1084/Si1085 Pin Definitions ........................................ 31 Table 3.4. QFN-36 Package Dimensions ................................................................ 38 Table 3.5. QFN-36 PCB Land Pattern Dimensions ................................................. 40 Table 4.1. Absolute Maximum Ratings .................................................................... 42 Table 4.2. Global Electrical Characteristics ............................................................. 43 Table 4.3. Port I/O DC Electrical Characteristics ..................................................... 52 Table 4.4. Reset Electrical Characteristics .............................................................. 57 Table 4.5. Power Management Electrical Specifications ......................................... 58 Table 4.6. Flash Electrical Characteristics .............................................................. 58 Table 4.7. Internal Precision Oscillator Electrical Characteristics ........................... 59 Table 4.8. Internal Low-Power Oscillator Electrical Characteristics ........................ 59 Table 4.9. ADC0 Electrical Characteristics .............................................................. 60 Table 4.10. Temperature Sensor Electrical Characteristics .................................... 61 Table 4.11. Voltage Reference Electrical Characteristics ....................................... 62 Table 4.12. Comparator Electrical Characteristics .................................................. 63 Table 4.13. DC-DC Converter (DC0) Electrical Characteristics .............................. 65 Table 4.14. VREG0 Electrical Characteristics ......................................................... 66 Table 4.15. DC Characteristics ................................................................................ 67 Table 4.16. Synthesizer AC Electrical Characteristics ............................................ 68 Table 4.17. Receiver AC Electrical Characteristics ................................................. 69 Table 4.18. Transmitter AC Electrical Characteristics ............................................ 73 Table 4.19. Auxiliary Block Specifications ............................................................... 75 Table 4.20. Digital IO Specifications (GPIO_x, nIRQ) ............................................. 75 Table 4.21. Absolute Maximum Ratings (Radio) ..................................................... 77 Table 4.22. Thermal Properties ............................................................................... 77 Table 7.1. CIP-51 Instruction Set Summary .......................................................... 115 Table 10.1. Special Function Register (SFR) Memory Map (Page 0x0) ............... 129 Table 10.2. Special Function Register (SFR) Memory Map (Page 0xF) ............... 130 Table 10.3. Special Function Registers ................................................................. 131 Table 10.4. Select Registers with Varying Function .............................................. 135 Table 11.1. Interrupt Summary .............................................................................. 139 Table 12.1. Flash Security Summary .................................................................... 152 Table 13.1. Power Modes ...................................................................................... 160 Table 14.1. Example 16-bit CRC Outputs ............................................................. 168 Table 14.2. Example 32-bit CRC Outputs ............................................................. 170 Table 15.1. IPeak Inductor Current Limit Settings ................................................. 176 Table 18.1. Recommended XFCN Settings for Crystal Mode ............................... 194 Table 18.2. Recommended XFCN Settings for RC and C modes ......................... 195 Table 19.1. SmaRTClock Internal Registers ......................................................... 201 Table 19.2. SmaRTClock Load Capacitance Settings .......................................... 208 Rev. 1.0 10 Si106x/108x Table 19.3. SmaRTClock Bias Settings ................................................................ 210 Table 20.1. Port I/O Assignment for Analog Functions ......................................... 220 Table 20.2. Port I/O Assignment for Digital Functions ........................................... 220 Table 20.3. Port I/O Assignment for External Digital Event Capture Functions .... 221 Table 21.1. Internal Connection for Radio and MCU ............................................. 238 Table 21.2. Serial Interface Timing Parameters .................................................... 238 Table 21.3. Operating State Response Time and Current Consumption Si1060/61/62/63, Si1080/81/82/83 ..................................................... 242 Table 21.4. Operating State Response Time and Current Consumption (Si1064/65, Si1084/85) ....................................................................... 242 Table 21.5. POR Timing ........................................................................................ 243 Table 21.6. GPIOs ................................................................................................. 247 Table 23.1. Recommended Preamble Length ....................................................... 251 Table 24.1. Output Divider (Outdiv) Values for the Si1060-Si1063, Si1080-1083 256 Table 24.2. Output Divider (Outdiv) for the Si1064/Si1065/Si1084/Si1085 ........... 256 Table 27.1. WUT Specific Commands and Properties .......................................... 264 Table 28.1. SMBus Clock Source Selection .......................................................... 271 Table 28.2. Minimum SDA Setup and Hold Times ................................................ 272 Table 28.3. Sources for Hardware Changes to SMB0CN ..................................... 276 Table 28.4. Hardware Address Recognition Examples (EHACK = 1) ................... 277 Table 28.5. SMBus Status Decoding With Hardware ACK Generation Disabled (EHACK = 0) ....................................................................................... 286 Table 28.6. SMBus Status Decoding With Hardware ACK Generation Enabled (EHACK = 1) ....................................................................................... 288 Table 29.1. Timer Settings for Standard Baud Rates Using The Internal 24.5 MHz Oscillator .............................................. 297 Table 29.2. Timer Settings for Standard Baud Rates Using an External 22.1184 MHz Oscillator ......................................... 297 Table 30.1. SPI Slave Timing Parameters ............................................................ 310 Table 31.1. Timer 0 Running Modes ..................................................................... 313 Table 32.1. PCA Timebase Input Options ............................................................. 334 Table 32.2. PCA0CPM and PCA0PWM Bit Settings for PCA Capture/Compare Modules .............................................................................................. 336 Table 32.3. Watchdog Timer Timeout Intervals1 ................................................... 345 11 Rev. 1.0 Si106x/108x List of Registers SFR Definition 5.1. ADC0CN: ADC0 Control ................................................................ 86 SFR Definition 5.2. ADC0CF: ADC0 Configuration ...................................................... 87 SFR Definition 5.3. ADC0AC: ADC0 Accumulator Configuration ................................. 88 SFR Definition 5.4. ADC0PWR: ADC0 Burst Mode Power-Up Time ............................ 89 SFR Definition 5.5. ADC0TK: ADC0 Burst Mode Track Time ....................................... 90 SFR Definition 5.6. ADC0H: ADC0 Data Word High Byte ............................................ 91 SFR Definition 5.7. ADC0L: ADC0 Data Word Low Byte .............................................. 91 SFR Definition 5.8. ADC0GTH: ADC0 Greater-Than High Byte ................................... 92 SFR Definition 5.9. ADC0GTL: ADC0 Greater-Than Low Byte .................................... 92 SFR Definition 5.10. ADC0LTH: ADC0 Less-Than High Byte ...................................... 93 SFR Definition 5.11. ADC0LTL: ADC0 Less-Than Low Byte ........................................ 93 SFR Definition 5.12. ADC0MX: ADC0 Input Channel Select ........................................ 96 SFR Definition 5.13. TOFFH: ADC0 Data Word High Byte .......................................... 99 SFR Definition 5.14. TOFFL: ADC0 Data Word Low Byte ............................................ 99 SFR Definition 5.15. REF0CN: Voltage Reference Control ........................................ 102 SFR Definition 6.1. CPT0CN: Comparator 0 Control .................................................. 106 SFR Definition 6.2. CPT0MD: Comparator 0 Mode Selection .................................... 107 SFR Definition 6.3. CPT1CN: Comparator 1 Control .................................................. 108 SFR Definition 6.4. CPT1MD: Comparator 1 Mode Selection .................................... 109 SFR Definition 6.5. CPT0MX: Comparator0 Input Channel Select ............................. 111 SFR Definition 6.6. CPT1MX: Comparator1 Input Channel Select ............................. 112 SFR Definition 7.1. DPL: Data Pointer Low Byte ........................................................ 119 SFR Definition 7.2. DPH: Data Pointer High Byte ....................................................... 119 SFR Definition 7.3. SP: Stack Pointer ......................................................................... 120 SFR Definition 7.4. ACC: Accumulator ....................................................................... 120 SFR Definition 7.5. B: B Register ................................................................................ 120 SFR Definition 7.6. PSW: Program Status Word ........................................................ 121 SFR Definition 9.1. EMI0CN: External Memory Interface Control .............................. 128 SFR Definition 10.1. SFRPage: SFR Page ................................................................. 131 SFR Definition 11.1. IE: Interrupt Enable .................................................................... 141 SFR Definition 11.2. IP: Interrupt Priority .................................................................... 142 SFR Definition 11.3. EIE1: Extended Interrupt Enable 1 ............................................ 143 SFR Definition 11.4. EIP1: Extended Interrupt Priority 1 ............................................ 144 SFR Definition 11.5. EIE2: Extended Interrupt Enable 2 ............................................ 145 SFR Definition 11.6. EIP2: Extended Interrupt Priority 2 ............................................ 146 SFR Definition 11.7. IT01CF: INT0/INT1 Configuration .............................................. 148 SFR Definition 12.1. PSCTL: Program Store R/W Control ......................................... 157 SFR Definition 12.2. FLKEY: Flash Lock and Key ...................................................... 158 SFR Definition 12.3. FLSCL: Flash Scale ................................................................... 159 SFR Definition 12.4. FLWR: Flash Write Only ............................................................ 159 SFR Definition 13.1. PMU0CF: Power Management Unit Configuration ..................... 165 SFR Definition 13.2. PCON: Power Management Control Register ........................... 166 SFR Definition 14.1. CRC0CN: CRC0 Control ........................................................... 171 SFR Definition 14.2. CRC0IN: CRC0 Data Input ........................................................ 172 Rev. 1.0 12 Si106x/108x SFR Definition 14.3. CRC0DAT: CRC0 Data Output .................................................. 172 SFR Definition 14.4. CRC0AUTO: CRC0 Automatic Control ...................................... 173 SFR Definition 14.5. CRC0CNT: CRC0 Automatic Flash Sector Count ..................... 173 SFR Definition 14.6. CRC0FLIP: CRC0 Bit Flip .......................................................... 174 SFR Definition 15.1. DC0CN: DC-DC Converter Control ........................................... 181 SFR Definition 15.2. DC0CF: DC-DC Converter Configuration .................................. 182 SFR Definition 16.1. REG0CN: Voltage Regulator Control ........................................ 184 SFR Definition 17.1. VDM0CN: VDD_MCU Supply Monitor Control .......................... 189 SFR Definition 17.2. RSTSRC: Reset Source ............................................................ 191 SFR Definition 18.1. CLKSEL: Clock Select ............................................................... 197 SFR Definition 18.2. OSCICN: Internal Oscillator Control .......................................... 198 SFR Definition 18.3. OSCICL: Internal Oscillator Calibration ..................................... 198 SFR Definition 18.4. OSCXCN: External Oscillator Control ........................................ 199 SFR Definition 19.1. RTC0KEY: SmaRTClock Lock and Key .................................... 204 SFR Definition 19.2. RTC0ADR: SmaRTClock Address ............................................ 205 SFR Definition 19.3. RTC0DAT: SmaRTClock Data .................................................. 206 Internal Register Definition 19.4. RTC0CN: SmaRTClock Control . . . . . . . . . . . . . . . 213 Internal Register Definition 19.5. RTC0XCN: SmaRTClock Oscillator Control . . . . . . 214 Internal Register Definition 19.6. RTC0XCF: SmaRTClock Oscillator Configuration . 215 Internal Register Definition 19.7. RTC0PIN: SmaRTClock Pin Configuration . . . . . . 215 Internal Register Definition 19.8. CAPTUREn: SmaRTClock Timer Capture . . . . . . . 216 Internal Register Definition 19.9. ALARMn: SmaRTClock Alarm Programmed Value 216 SFR Definition 20.1. XBR0: Port I/O Crossbar Register 0 .......................................... 224 SFR Definition 20.2. XBR1: Port I/O Crossbar Register 1 .......................................... 225 SFR Definition 20.3. XBR2: Port I/O Crossbar Register 2 .......................................... 226 SFR Definition 20.4. P0MASK: Port0 Mask Register .................................................. 227 SFR Definition 20.5. P0MAT: Port0 Match Register ................................................... 227 SFR Definition 20.6. P1MASK: Port1 Mask Register .................................................. 228 SFR Definition 20.7. P1MAT: Port1 Match Register ................................................... 228 SFR Definition 20.8. P0: Port0 .................................................................................... 230 SFR Definition 20.9. P0SKIP: Port0 Skip .................................................................... 230 SFR Definition 20.10. P0MDIN: Port0 Input Mode ...................................................... 231 SFR Definition 20.11. P0MDOUT: Port0 Output Mode ............................................... 231 SFR Definition 20.12. P0DRV: Port0 Drive Strength .................................................. 232 SFR Definition 20.13. P1: Port1 .................................................................................. 233 SFR Definition 20.14. P1SKIP: Port1 Skip .................................................................. 233 SFR Definition 20.15. P1MDIN: Port1 Input Mode ...................................................... 234 SFR Definition 20.16. P1MDOUT: Port1 Output Mode ............................................... 234 SFR Definition 20.17. P1DRV: Port1 Drive Strength .................................................. 235 SFR Definition 20.18. P2: Port2 .................................................................................. 235 SFR Definition 20.19. P2SKIP: Port2 Skip .................................................................. 236 SFR Definition 20.20. P2MDIN: Port2 Input Mode ...................................................... 236 SFR Definition 20.21. P2MDOUT: Port2 Output Mode ............................................... 237 SFR Definition 20.22. P2DRV: Port2 Drive Strength .................................................. 237 SFR Definition 28.1. SMB0CF: SMBus Clock/Configuration ...................................... 273 13 Rev. 1.0 Si106x/108x SFR Definition 28.2. SMB0CN: SMBus Control .......................................................... 275 SFR Definition 28.3. SMB0ADR: SMBus Slave Address ............................................ 278 SFR Definition 28.4. SMB0ADM: SMBus Slave Address Mask .................................. 278 SFR Definition 28.5. SMB0DAT: SMBus Data ............................................................ 281 SFR Definition 29.1. SCON0: Serial Port 0 Control .................................................... 295 SFR Definition 29.2. SBUF0: Serial (UART0) Port Data Buffer .................................. 296 SFR Definition 30.7. SPI0CFG: SPI0 Configuration ................................................... 305 SFR Definition 30.8. SPI0CN: SPI0 Control ............................................................... 306 SFR Definition 30.9. SPI0CKR: SPI0 Clock Rate ....................................................... 307 SFR Definition 30.10. SPI0DAT: SPI0 Data ............................................................... 307 SFR Definition 31.1. CKCON: Clock Control .............................................................. 312 SFR Definition 31.2. TCON: Timer Control ................................................................. 317 SFR Definition 31.3. TMOD: Timer Mode ................................................................... 318 SFR Definition 31.4. TL0: Timer 0 Low Byte ............................................................... 319 SFR Definition 31.5. TL1: Timer 1 Low Byte ............................................................... 319 SFR Definition 31.6. TH0: Timer 0 High Byte ............................................................. 320 SFR Definition 31.7. TH1: Timer 1 High Byte ............................................................. 320 SFR Definition 31.8. TMR2CN: Timer 2 Control ......................................................... 324 SFR Definition 31.9. TMR2RLL: Timer 2 Reload Register Low Byte .......................... 325 SFR Definition 31.10. TMR2RLH: Timer 2 Reload Register High Byte ...................... 325 SFR Definition 31.11. TMR2L: Timer 2 Low Byte ....................................................... 326 SFR Definition 31.12. TMR2H Timer 2 High Byte ....................................................... 326 SFR Definition 31.13. TMR3CN: Timer 3 Control ....................................................... 330 SFR Definition 31.14. TMR3RLL: Timer 3 Reload Register Low Byte ........................ 331 SFR Definition 31.15. TMR3RLH: Timer 3 Reload Register High Byte ...................... 331 SFR Definition 31.16. TMR3L: Timer 3 Low Byte ....................................................... 332 SFR Definition 31.17. TMR3H Timer 3 High Byte ....................................................... 332 SFR Definition 32.1. PCA0CN: PCA Control .............................................................. 346 SFR Definition 32.2. PCA0MD: PCA Mode ................................................................ 347 SFR Definition 32.3. PCA0PWM: PCA PWM Configuration ....................................... 348 SFR Definition 32.4. PCA0CPMn: PCA Capture/Compare Mode .............................. 349 SFR Definition 32.5. PCA0L: PCA Counter/Timer Low Byte ...................................... 350 SFR Definition 32.6. PCA0H: PCA Counter/Timer High Byte ..................................... 350 SFR Definition 32.7. PCA0CPLn: PCA Capture Module Low Byte ............................. 351 SFR Definition 32.8. PCA0CPHn: PCA Capture Module High Byte ........................... 351 C2 Register Definition 34.1. C2ADD: C2 Address ...................................................... 353 C2 Register Definition 34.2. DEVICEID: C2 Device ID ............................................... 354 C2 Register Definition 34.3. REVID: C2 Revision ID .................................................. 354 C2 Register Definition 34.4. FPCTL: C2 Flash Programming Control ........................ 355 C2 Register Definition 34.5. FPDAT: C2 Flash Programming Data ............................ 355 Rev. 1.0 14 Si106x/108x 1. System Overview Silicon Laboratories' Si106x Wireless MCUs combine high-performance wireless connectivity and ultra-low power microcontroller processing into a small 5x6 mm form factor. Support for major frequency bands in the 142 to 1050 MHz range is provided including an integrated advanced packet handling engine and the ability to realize a link budget of up to 146 dB. The devices have been optimized to minimize energy consumption for battery-backed applications by minimizing TX, RX, active, and sleep mode current as well as supporting fast wake-up times. The Si106x and Si108x Wireless MCUs are pin-compatible and can scale from 8 to 64 kB of flash and provides a robust set of analog and digital peripherals including an ADC, dual comparators, timers, and GPIO. All devices are designed to be compliant with the 802.15.4g smart metering standard and support worldwide regulatory standards including FCC, ETSI, and ARIB. Refer to Table 2.1 for specific product feature selection and part ordering numbers. With on-chip power-on reset, VDD monitor, watchdog timer, and clock oscillator, the Si106x devices are truly standalone system-on-a-chip solutions. The flash memory can be reprogrammed even in-circuit, providing non-volatile data storage, and also allowing field upgrades of the 8051 firmware. User software has complete control of all peripherals, and may individually shut down any or all peripherals for power savings. The on-chip Silicon Labs 2-Wire (C2) Development Interface allows non-intrusive (uses no on-chip resources), full speed, in-circuit debugging using the production MCU installed in the final application. This debug logic supports inspection and modification of memory and registers, setting breakpoints, single stepping, and run and halt commands. All analog and digital peripherals are fully functional while debugging using C2. The two C2 interface pins can be shared with user functions, allowing in-system debugging without occupying package pins. Each device is specified for 1.8 to 3.6 V operation over the industrial temperature range (-40 to +85 C). Select devices will work down to 0.9 V with the dc-dc boost converter, supporting operation on a single alkaline cell battery. The Port I/O and RST pins are tolerant of input signals up to 5 V. The Si106x devices are available in a 36-pin QFN package (lead-free and RoHS compliant). See Table 2.1 for ordering information. See Figure 1.1 for the block diagram. The transceiver's extremely low receive sensitivity (-126 dBm) coupled with industry leading +20 dBm output power ensures extended range and improved link performance. Built-in antenna diversity and support for frequency hopping can be used to further extend range and enhance performance. The advanced radio supports major frequency bands in the 119 to 1050 MHz range. The Si106x family includes optimal phase noise, blocking, and selectivity performance for narrow band and licensed band applications such as FCC Part90 and 169 MHz wireless Mbus. The 60 dB adjacent channel selectivity with 12.5 kHz channel spacing ensures robust receive operation in harsh RF conditions, which is particularly important for narrow band operation. The Si106x offers exceptional output power of up to +20 dBm with outstanding TX efficiency. The high output power and sensitivity results in an industry-leading link budget of 146 dB allowing extended ranges and highly robust communication links. The active mode TX current consumption of 18 mA at +10 dBm and RX current of 10 mA coupled with extremely low standby current and fast wake times ensure extended battery life in the most demanding applications. The Si106x wireless MCUs can achieve up to +27 dBm output power with built-in ramping control of a low-cost external FET. The devices are highly flexible and can be configured via Silicon Labs' graphical configuration tools. Rev. 1.0 15 Si106x/108x Power On Reset/PMU Wake Reset RST/C2CK Debug / Programming Hardware CIP-51 8051 Controller Core Analog Peripherals ISP Flash Program Memory Internal External VREF VREF SRAM A M U X 10-bit 300ksps ADC XRAM VDD VREF Temp Sensor GND C2D VDD CP0, CP0A CRC Engine VREG CP1, CP1A Precision 24.5 MHz Oscillator SFR Bus P0.3/XTAL2 XTAL3 XTAL4 Digital Peripherals TX AGC RXp RXn LNA Mixer ADC Modem FIFO Packet Handler Digital Logic 4 GPIO UART External Oscillator Circuit Timers 0, 1, 2, 3 SmaRTClock Oscillator PCA/ WDT SPI 0 Figure 1.1. Si106x/Si108x Block Diagram Rev. 1.0 XIN XOUT OSC Priority Crossbar Decoder LDO POR SMBus System Clock Configuration 16 PA PGA Transceiver Control Interface Low Power 20 MHz Oscillator P0.2/XTAL1 + - Comparators SYSCLK GND + - RF XCVR Port I/O Config VDD 11 ANALOG & DIGITAL I/O Si106x/108x 1.1. Typical Connection Diagram The application shown in Figure 1.2 is designed for a system with a TX/RX direct-tie configuration without the use of a TX/RX switch. Most lower power applications will use this configuration. A complete direct-tie reference design is available from Silicon Laboratories applications support. For applications seeking improved performance in the presence of multipath fading, antenna diversity can be used. Antenna diversity support is integrated into the EZRadioPRO transceiver and can improve the system link budget by 8-10 dB in the presence of these fading conditions, resulting in substantial range increases. A complete Antenna Diversity reference design is available from Silicon Laboratories applications support. Figure 1.2. Si106x/108x RX/TX Direct-Tie Application Example Figure 1.3. Si106x/108x Antenna Diversity Application Example Rev. 1.0 17 Si106x/108x 1.2. CIP-51TM Microcontroller Core 1.2.1. Fully 8051 Compatible The Si106x/108x family utilizes Silicon Labs' proprietary CIP-51 microcontroller core. The CIP-51 is fully compatible with the MCS-51TM instruction set; standard 803x/805x assemblers and compilers can be used to develop software. The CIP-51 core offers all the peripherals included with a standard 8052. 1.2.2. Improved Throughput The CIP-51 employs a pipelined architecture that greatly increases its instruction throughput over the standard 8051 architecture. In a standard 8051, all instructions except for MUL and DIV take 12 or 24 system clock cycles to execute with a maximum system clock of 12-to-24 MHz. By contrast, the CIP-51 core executes 70% of its instructions in one or two system clock cycles, with only four instructions taking more than four system clock cycles. The CIP-51 has a total of 109 instructions. The table below shows the total number of instructions that require each execution time. Clocks to Execute 1 2 2/3 3 3/4 4 4/5 5 8 Number of Instructions 26 50 5 14 7 3 1 2 1 With the CIP-51's maximum system clock at 25 MHz, it has a peak throughput of 25 MIPS. 1.2.3. Additional Features The Si106x/108x SoC family includes several key enhancements to the CIP-51 core and peripherals to improve performance and ease of use in end applications. The extended interrupt handler provides multiple interrupt sources into the CIP-51, allowing numerous analog and digital peripherals to interrupt the controller. An interrupt driven system requires less intervention by the MCU, giving it more effective throughput. The extra interrupt sources are very useful when building multi-tasking, real-time systems. Eight reset sources are available: power-on reset circuitry (POR), an on-chip VDD monitor (forces reset when power supply voltage drops below safe levels), a watchdog timer, a Missing Clock Detector, SmaRTClock oscillator fail or alarm, a voltage level detection from Comparator0, a forced software reset, an external reset pin, and an illegal flash access protection circuit. Each reset source except for the POR, Reset Input Pin, or flash error may be disabled by the user in software. The WDT may be permanently disabled in software after a power-on reset during MCU initialization. The internal oscillator factory is calibrated to 24.5 MHz and is accurate to 2% over the full temperature and supply range. The internal oscillator period can also be adjusted by user firmware. An additional 20 MHz low power oscillator is also available which facilitates low-power operation. An external oscillator drive circuit is included, allowing an external crystal, ceramic resonator, capacitor, RC, or CMOS clock source to generate the system clock. If desired, the system clock source may be switched between both internal and external oscillator circuits. An external oscillator can also be extremely useful in low power applications, allowing the MCU to run from a slow (power saving) source, while periodically switching to the fast (up to 25 MHz) internal oscillator as needed. 18 Rev. 1.0 Si106x/108x 1.3. Port Input/Output Digital and analog resources are available through 11 I/O pins. Four additional GPIO pins are available through the radio peripheral. Port pins are organized as three byte-wide ports. Port pins P0.0-P0.6 and P1.4-P1.6 can be defined as digital or analog I/O. Digital I/O pins can be assigned to one of the internal digital resources or used as general purpose I/O (GPIO). Analog I/O pins are used by the internal analog resources. P2.7 can be used as GPIO and is shared with the C2 Interface Data signal (C2D). See Section "33. Device Specific Behavior" on page 352 for more details. The designer has complete control over which digital and analog functions are assigned to individual port pins and is limited only by the number of physical I/O pins. This resource assignment flexibility is achieved through the use of a Priority Crossbar Decoder. See Section "20.3. Priority Crossbar Decoder" on page 221 for more information on the crossbar. All Px.x Port I/Os are 5 V tolerant when used as digital inputs or open-drain outputs. For Port I/Os configured as push-pull outputs, current is sourced from the VDD_MCU supply. Port I/Os used for analog functions can operate up to the VDD_MCU supply voltage. See Section "20.1. Port I/O Modes of Operation" on page 218 for more information on Port I/O operating modes and the electrical specifications chapter for detailed electrical specifications. XBR0, XBR1, XBR2, PnSKIP Registers Port Match P0MASK, P0MAT P1MASK, P1MAT External Interrupts EX0 and EX1 Priority Decoder Highest Priority UART 4 (Internal Digital Signals) SPI0 SPI1 SMBus CP0 CP1 Outputs P0.0 2 Digital Crossbar 8 4 8 7 T0, T1 P0 I/O Cells P0.6 SYSCLK PCA Lowest Priority PnMDOUT, PnMDIN Registers 2 P1.4 P1 I/O Cells P1.5 P1.6 2 8 (Port Latches) P0 8 (P0.0-P0.7) 8 P1 (P1.0-P1.7) 8 P2 (P2.0-P2.7) P2 I/O Cell P2.7 To Analog Peripherals (ADC0, CP0, and CP1 inputs, VREF, AGND) No analog functionality available on P2.7 Note: P0.7, P1.0, P1.1, P1.2 and P1.3 are internally connected to the radio peripheral. P1.7 and P2.0 - P2.6 are not internally or externally connected. Figure 1.4. Port I/O Functional Block Diagram Rev. 1.0 19 Si106x/108x 1.4. Serial Ports The Si106x/108x family includes an SMBus/I2C interface, a full-duplex UART with enhanced baud rate configuration, and an Enhanced SPI interface. Each of the serial buses is fully implemented in hardware and makes extensive use of the CIP-51's interrupts, thus requiring very little CPU intervention. There is also a dedicated radio serial interface (SPI1) to allow communication with the radio peripheral. 1.5. Programmable Counter Array An on-chip Programmable Counter/Timer Array (PCA) is included in addition to the four 16-bit general purpose counter/timers. The PCA consists of a dedicated 16-bit counter/timer time base with six programmable capture/compare modules. The PCA clock is derived from one of six sources: the system clock divided by 12, the system clock divided by 4, Timer 0 overflows, an External Clock Input (ECI), the system clock, or the external oscillator clock source divided by 8. Each capture/compare module can be configured to operate in a variety of modes: edge-triggered capture, software timer, high-speed output, pulse width modulator (8, 9, 10, 11, or 16-bit), or frequency output. Additionally, Capture/Compare Module 5 offers watchdog timer capabilities. Following a system reset, Module 5 is configured and enabled in WDT mode. The PCA Capture/Compare Module I/O and External Clock Input may be routed to Port I/O via the Digital Crossbar. SYSCLK /12 SYSCLK /4 Timer 0 Overflow ECI PCA CLOCK MUX 16 -Bit Counter/Timer SYSCLK External Clock /8 Capture/ Compare Module 0 Capture/ Compare Module 1 Capture/ Compare Module 2 Capture/ Compare Module 3 Figure 1.5. PCA Block Diagram 20 Rev. 1.0 Capture/ Compare Module5 / WDT CEX5 Port I/O CEX4 CEX3 CEX2 CEX1 CEX0 ECI Crossbar Capture/ Compare Module 4 Si106x/108x 1.6. 10-bit SAR ADC with 16-bit Auto-Averaging Accumulator and Autonomous Low Power Burst Mode Si106x/108x devices have a 300 ksps, 10-bit successive-approximation-register (SAR) ADC with integrated track-and-hold and programmable window detector. ADC0 also has an autonomous low power Burst Mode which can automatically enable ADC0, capture and accumulate samples, then place ADC0 in a low power shutdown mode without CPU intervention. It also has a 16-bit accumulator that can automatically average the ADC results, providing an effective 11, 12, or 13-bit ADC result without any additional CPU intervention. The ADC can sample the voltage at any of the MCU GPIO pins (with the exception of P2.7) and has an onchip attenuator that allows it to measure voltages up to twice the voltage reference. Additional ADC inputs include an on-chip temperature sensor, the VDD_MCU supply voltage, the VBAT supply voltage, and the internal digital supply voltage. VDD ADC AD0CM1 AD0CM2 AD0CM0 010 011 100 Timer 2 Overflow Timer 3 Overflow CNVSTR Input REF 16-Bit Accumulator SYSCLK AD0TM AMP0GN AD08BE AD0SC0 AD0SC1 ADC0CF AD0BUSY (W) Timer 0 Overflow ADC0LTH ADC0H AIN+ 000 001 ADC0L 10-bit SAR AD0SC2 From AMUX0 Start Conversion Burst Mode Logic AD0SC3 ADC0PWR AD0SC4 ADC0TK AD0WINT AD0INT AD0BUSY BURSTEN AD0EN ADC0CN AD0WINT ADC0LTL 32 Window Compare Logic ADC0GTH ADC0GTL Figure 1.6. ADC0 Functional Block Diagram Rev. 1.0 21 Si106x/108x AD0MX4 AD0MX3 AD0MX2 AD0MX1 AM0MX0 ADC0MX P0.0 Programmable Attenuator AIN+ P2.6* AMUX Temp Sensor ADC0 Gain = 0. 5 or 1 Digital Supply VDD_MCU *P1.0 - P1.4 are not available as device pins Figure 1.7. ADC0 Multiplexer Block Diagram 1.7. Comparators Si106x/108x devices include two on-chip programmable voltage comparators: Comparator 0 (CPT0), which is shown in Figure 1.8, and Comparator 1 (CPT1), which is shown in Figure 1.9. The two comparators operate identically but may differ in their ability to be used as reset or wake-up sources. See Section "17. Reset Sources" on page 185 and Section "13. Power Management" on page 160 for details on reset sources and low power mode wake-up sources, respectively. The comparators offer programmable response time and hysteresis, an analog input multiplexer, and two outputs that are optionally available at the Port pins: a synchronous "latched" output (CP0, CP1), or an asynchronous "raw" output (CP0A, CP1A). The asynchronous CP0A signal is available even when the system clock is not active. This allows the comparator to operate and generate an output when the device is in some low power modes. The comparator inputs may be connected to Port I/O pins or to other internal signals. Port pins may also be used to directly sense capacitive touch switches. See Application Note "AN338: Capacitive Touch Sense Solution" for details on Capacitive Touch Switch sensing. 22 Rev. 1.0 CPT0CN Si106x/108x CP0EN CP0OUT CP0RIF CP0FIF VDD CP0HYP1 CP0HYP0 CP0HYN1 CP0 Interrupt CP0HYN0 CPT0MD Analog Input Multiplexer CP0FIE CP0RIE CP0MD1 CP0MD0 Px.x CP0 Rising-edge CP0 + CP0 Falling-edge Interrupt Logic Px.x CP0 + SET D - CLR D Q Q SET CLR Q Q Px.x Crossbar (SYNCHRONIZER) GND CP0 - CP0A (ASYNCHRONOUS) Reset Decision Tree Px.x Figure 1.8. Comparator 0 Functional Block Diagram CPT0CN CP1EN CP1OUT CP1RIF VDD CP1FIF CP1HYP1 CP1 Interrupt CP1HYP0 CP1HYN1 CP1HYN0 CPT0MD Analog Input Multiplexer CP1FIE CP1RIE CP1MD1 CP1MD0 Px.x CP1 Rising-edge CP1 + CP1 Falling-edge Interrupt Logic Px.x CP1 + D - SET CLR Q Q D SET CLR Q Q Px.x Crossbar (SYNCHRONIZER) CP1 - GND (ASYNCHRONOUS) CP1A Reset Decision Tree Px.x Figure 1.9. Comparator 1 Functional Block Diagram Rev. 1.0 23 2. Si106x/108x Ordering Information Table 2.1. Orderable Part Number Frequency 64 KB 64 KB 64 KB 32 KB 32 KB 32 KB 16 KB 16 KB 16 KB 8 KB 8 KB 8 KB 4 KB 4 KB 4 KB 4 KB 4 KB 4 KB 768 bytes 768 bytes 768 bytes 768 bytes 768 bytes 768 bytes No Yes Yes No Yes Yes No Yes Yes No Yes Yes 960-1050 MHz DC-DC Boost 850-960 MHz EZRadioPro EZRadioPro EZRadio EZRadioPro EZRadioPro EZRadio EZRadioPro EZRadioPro EZRadio EZRadioPro EZRadioPro EZRadio RAM 425-525 MHz Si1060-A-GM Si1062-A-GM Si1064-A-GM Si1061-A-GM Si1063-A-GM Si1065-A-GM Si1080-A-GM Si1082-A-GM Si1084-A-GM Si1081-A-GM Si1083-A-GM Si1085-A-GM Flash 283-350 MHz Radio 142-175 MHz Orderable Part Number Max Output Power +20 dBm +13 dBm +13 dBm +20 dBm +13 dBm +13 dBm +20 dBm +13 dBm +13 dBm +20 dBm +13 dBm +13 dBm Max Data Rate Max 40Kbps, GFSK 1 Mbps 1 Mbps 500 kbps 1 Mbps 1 Mbps 500 kbps 1 Mbps 1 Mbps 500 kbps 1 Mbps 1 Mbps 500 kbps -126 dBm -126 dBm -116 dBm -126 dBm -126 dBm -116 dBm -126 dBm -126 dBm -116 dBm -126 dBm -126 dBm -116 dBm -110 dBm -110 dBm -108 dBm -110 dBm -110 dBm -108 dBm -110 dBm -110 dBm -108 dBm -110 dBm -110 dBm -108 dBm *Note: Advanced features include antenna diversity, narrowband support and autonomous low-duty cycle support. 24 Rev. 1.0 Sensitivity Advanced Features* Yes Yes No Yes Yes No Yes Yes No Yes Yes No Si106x/108x 3. Pinout and Package Definitions Table 3.1. Si1060/Si1061/Si1080/Si1081 Pin Definitions Pin Designation Description 1 P2.7/C2D Port 2.7. This pin can only be used as GPIO. The Crossbar cannot route signals to this pin and it cannot be configured as an analog input. See Port I/O section for a complete description. Bi-directional data signal for the C2 Debug Interface. 2 XTAL4 SmaRTClock Oscillator Crystal Output. See Section 20 for a complete description. 3 XTAL3 SmaRTClock Oscillator Crystal Input. See Section 20 for a complete description. 4 P1.6 Port 1.6. See Port I/O section for a complete description. 5 P1.5 Port 1.5. See Port I/O section for a complete description. 6 P1.4 Port 1.4. See Port I/O section for a complete description. 7 XOUT 8 XIN 9 GND_RF 10 GPIO2 General Purpose I/O controlled by the EZRadioPRO peripheral. May be configured through the EZRadioPRO registers to perform various functions including: Clock Output, FIFO status, POR, Wake-Up Timer, TRSW, AntDiversity control, etc. See the EZRadioPRO GPIO Configuration Registers for more information. 11 GPIO3 General Purpose I/O controlled by the EZRadioPRO peripheral. May be configured through the EZRadioPRO registers to perform various functions including: Clock Output, FIFO status, POR, Wake-Up Timer, TRSW, AntDiversity control, etc. See the EZRadioPRO GPIO Configuration Registers for more information. 12 RXP EZRadioPRO peripheral differential RF input pins of the LNA. See application schematic for example matching network. 13 RXN EZRadioPRO peripheral differential RF input pins of the LNA. See application schematic for example matching network. 14 GND_RF Required ground for the digital and analog portions of the EZRadioPRO peripheral. 15 GND_RF Required ground for the digital and analog portions of the EZRadioPRO peripheral. Crystal Oscillator Output. Connect to an external 25 to 32 MHz crystal, or leave floating when driving with an external source on XIN. Crystal Oscillator Input. Connect to an external 25 to 32 MHz crystal, or connect to an external source. Required ground for the digital and analog portions of the EZRadioPRO peripheral. Rev. 1.0 25 Si106x/108x Table 3.1. Si1060/Si1061/Si1080/Si1081 Pin Definitions (Continued) 26 Pin Designation Description 16 TX EZRadioPRO peripheral transmit RF output pin. The PA output is an opendrain connection so the L-C match must supply 1.8 to 3.6 VDC to this pin. 17 GND_RF Required ground for the digital and analog portions of the EZRadioPRO peripheral. 18 VDD_RF Power Supply Voltage for the analog portion of the EZRadioPRO peripheral. Must be 1.8 to 3.6 V. 19 TXRAMP Programmable Bias Output with Ramp Capability for external FET PA. 20 VDD_RF Power Supply Voltage for the analog portion of the EZRadioPRO peripheral. Must be 1.8 to 3.6 V. 21 GPIO0 General Purpose I/O controlled by the EZRadioPRO peripheral. May be configured through the EZRadioPRO registers to perform various functions including: Clock Output, FIFO status, POR, Wake-Up Timer, TRSW, AntDiversity control, etc. See the EZRadioPRO GPIO Configuration Registers for more information. 22 GPIO1 General Purpose I/O controlled by the EZRadioPRO peripheral. May be configured through the EZRadioPRO registers to perform various functions including: Clock Output, FIFO status, POR, Wake-Up Timer, TRSW, AntDiversity control, etc. See the EZRadioPRO GPIO Configuration Registers for more information. 23 IRQ EZRadioPRO peripheral interrupt status pin. Will be set low to indicate a pending EZRadioPRO interrupt event. See the EZRadioPRO Control Logic Registers for more details. This pin is an open-drain output with a 220 k internal pullup resistor. An external pull-up resistor is recommended. 24 P0.6/CNVSTR 25 P0.5/RX Port 0.5. See Port I/O section for a complete description. UART RX Pin. See Port I/O section. 26 P0.4/TX Port 0.4. See Port I/O section for a complete description. UART TX Pin. See Port I/O section. 27 P0.3/XTAL2 Port 0.3. See Port I/O Section for a complete description. External Clock Output. This pin is the excitation driver for an external crystal or resonator. External Clock Input. This pin is the external clock input in external CMOS clock mode. External Clock Input. This pin is the external clock input in capacitor or RC oscillator configurations. See Oscillator section for complete details. 28 P0.2/XTAL1 Port 0.2. See Port I/O Section for a complete description. External Clock Input. This pin is the external oscillator return for a crystal or resonator. See Oscillator section. Port 0.6. See Port I/O section for a complete description. External Convert Start Input for ADC0. See ADC0 section for a complete description. Rev. 1.0 Si106x/108x Table 3.1. Si1060/Si1061/Si1080/Si1081 Pin Definitions (Continued) Pin Designation Description 29 P0.1/AGND Port 0.1. See Port I/O Section for a complete description. Optional Analog ground. See VREF chapter. 30 P0.0/VREF Port 0.0. See Port I/O section for a complete description. External VREF Input. Internal VREF Output. External VREF decoupling capacitors are recommended. See Voltage Reference section. 31 GND_MCU Required ground for the entire MCU except for the EZRadioPRO peripheral 32 NC 33 VDD_MCU 34 NC No Connect 35 NC No Connect 36 RST/C2CK No Connect Power Supply Voltage for the entire MCU except for the EZRadioPRO peripheral. Must be 1.8 to 3.6 V. This supply voltage is not required in low power sleep mode. This voltage must always be > VBAT. Device Reset. Open-drain output of internal POR or VDD monitor. An external source can initiate a system reset by driving this pin low for at least 15 s. A 1-5 k pullup to VDD_MCU is recommended. See Reset Sources section for a complete description. Clock signal for the C2 Debug Interface. Rev. 1.0 27 Si106x/108x Table 3.2. Si1062/Si1063/Si1082/Si1083 Pin Definitions 28 Pin Designation Description 1 P2.7/C2D Port 2.7. This pin can only be used as GPIO. The Crossbar cannot route signals to this pin and it cannot be configured as an analog input. See Port I/O section for a complete description. Bi-directional data signal for the C2 Debug Interface. 2 XTAL4 SmaRTClock Oscillator Crystal Output. See Section 20 for a complete description. 3 XTAL3 SmaRTClock Oscillator Crystal Input. See Section 20 for a complete description. 4 P1.6 Port 1.6. See Port I/O section for a complete description. 5 P1.5 Port 1.5. See Port I/O section for a complete description. 6 P1.4 Port 1.4. See Port I/O section for a complete description. 7 XOUT 8 XIN 9 GND_RF 10 GPIO2 General Purpose I/O controlled by the EZRadioPRO peripheral. May be configured through the EZRadioPRO registers to perform various functions including: Clock Output, FIFO status, POR, Wake-Up Timer, TRSW, AntDiversity control, etc. See the EZRadioPRO GPIO Configuration Registers for more information. 11 GPIO3 General Purpose I/O controlled by the EZRadioPRO peripheral. May be configured through the EZRadioPRO registers to perform various functions including: Clock Output, FIFO status, POR, Wake-Up Timer, TRSW, AntDiversity control, etc. See the EZRadioPRO GPIO Configuration Registers for more information. 12 RXP EZRadioPRO peripheral differential RF input pins of the LNA. See application schematic for example matching network. 13 RXN EZRadioPRO peripheral differential RF input pins of the LNA. See application schematic for example matching network. 14 TX 15 GND_RF Required ground for the digital and analog portions of the EZRadioPRO peripheral. 16 GND_RF Required ground for the digital and analog portions of the EZRadioPRO peripheral. 17 GND_RF Required ground for the digital and analog portions of the EZRadioPRO peripheral. Crystal Oscillator Output. Connect to an external 25 to 32 MHz crystal or leave floating when driving with an external source on XIN. Crystal Oscillator Input. Connect to an external 25 to 32 MHz crystal or connect to an external source. Required ground for the digital and analog portions of the EZRadioPRO peripheral. EZRadioPRO peripheral transmit RF output pin. The PA output is an opendrain connection so the L-C match must supply 1.8 to 3.6 VDC to this pin. Rev. 1.0 Si106x/108x Table 3.2. Si1062/Si1063/Si1082/Si1083 Pin Definitions (Continued) Pin Designation Description 18 VDD_RF Power Supply Voltage for the analog portion of the EZRadioPRO peripheral. Must be 1.8 to 3.6 V. 19 TXRAMP Programmable Bias Output with Ramp Capability for External FET PA. 20 VDD_RF Power Supply Voltage for the analog portion of the EZRadioPRO peripheral. Must be 1.8 to 3.6 V. 21 GPIO0 General Purpose I/O controlled by the EZRadioPRO peripheral. May be configured through the EZRadioPRO registers to perform various functions including: Clock Output, FIFO status, POR, Wake-Up Timer, TRSW, AntDiversity control, etc. See the EZRadioPRO GPIO Configuration Registers for more information. 22 GPIO1 General Purpose I/O controlled by the EZRadioPRO peripheral. May be configured through the EZRadioPRO registers to perform various functions including: Clock Output, FIFO status, POR, Wake-Up Timer, TRSW, AntDiversity control, etc. See the EZRadioPRO GPIO Configuration Registers for more information. 23 IRQ EZRadioPRO peripheral interrupt status pin. Will be set low to indicate a pending EZRadioPRO interrupt event. See the EZRadioPRO Control Logic Registers for more details. This pin is an open-drain output with a 220 k internal pullup resistor. An external pull-up resistor is recommended. 24 P0.6/CNVSTR 25 P0.5/RX Port 0.5. See Port I/O section for a complete description. UART RX Pin. See Port I/O section. 26 P0.4/TX Port 0.4. See Port I/O section for a complete description. UART TX Pin. See Port I/O section. 27 P0.3/XTAL2 Port 0.3. See Port I/O Section for a complete description. External Clock Output. This pin is the excitation driver for an external crystal or resonator. External Clock Input. This pin is the external clock input in external CMOS clock mode. External Clock Input. This pin is the external clock input in capacitor or RC oscillator configurations. See Oscillator section for complete details. 28 P0.2/XTAL1 Port 0.2. See Port I/O Section for a complete description. External Clock Input. This pin is the external oscillator return for a crystal or resonator. See Oscillator section. 29 P0.1/AGND Port 0.1. See Port I/O Section for a complete description. Optional Analog ground. See VREF chapter. Port 0.6. See Port I/O section for a complete description. External Convert Start Input for ADC0. See ADC0 section for a complete description. Rev. 1.0 29 Si106x/108x Table 3.2. Si1062/Si1063/Si1082/Si1083 Pin Definitions (Continued) Pin Designation 30 P0.0/VREF 31 32 33 30 Description Port 0.0. See Port I/O section for a complete description. External VREF Input. Internal VREF Output. External VREF decoupling capacitors are recommended. See Voltage Reference section. GND_MCU/DC- DC-DC converter return current path. In single-cell battery mode, this pin is typically not connected to ground. In dual-cell battery mode, this pin must be connected directly to ground. GND_MCU/ VBAT- Required ground for the entire MCU except for the EZRadioPRO peripheral. VDD_MCU/DC+ Power Supply Voltage. Must be 1.8 to 3.6 V. This supply voltage is not required in low power sleep mode. This voltage must always be > VBAT. Positive output of the dc-dc converter. In single-cell battery mode, a 1 F ceramic capacitor is required between DC+ and DC-. This pin can supply power to external devices when operating in single-cell battery mode. 34 DCEN DC-DC Enable Pin. In single-cell battery mode, this pin must be connected to VBAT through a 0.68 H inductor. In dual-cell battery mode, this pin must be connected directly to ground. 35 VBAT+ Battery Supply Voltage. Must be 0.9 to 1.8 V in single-cell battery mode and 1.8 to 3.6 V in dual-cell battery mode. 36 RST/C2CK Device Reset. Open-drain output of internal POR or VDD monitor. An external source can initiate a system reset by driving this pin low for at least 15 s. A 1-5 k pullup to VDD_MCU is recommended. See Reset Sources section for a complete description. Clock signal for the C2 Debug Interface. Rev. 1.0 Si106x/108x Table 3.3. Si1064/Si1065/Si1084/Si1085 Pin Definitions Pin Designation Description 1 P2.7/C2D Port 2.7. This pin can only be used as GPIO. The Crossbar cannot route signals to this pin and it cannot be configured as an analog input. See Port I/O section for a complete description. Bi-directional data signal for the C2 Debug Interface. 2 XTAL4 SmaRTClock Oscillator Crystal Output. See Section 20 for a complete description. 3 XTAL3 SmaRTClock Oscillator Crystal Input. See Section 20 for a complete description. 4 P1.6 Port 1.6. See Port I/O section for a complete description. 5 P1.5 Port 1.5. See Port I/O section for a complete description. 6 P1.4 Port 1.4. See Port I/O section for a complete description. 7 XOUT 8 XIN 9 GND_RF 10 GPIO2 General Purpose I/O controlled by the EZRadio peripheral. May be configured through the EZRadio registers to perform various functions including: Clock Output, FIFO status, POR, Wake-Up Timer, TRSW, AntDiversity control, etc. See the EZRadio GPIO Configuration Registers for more information. 11 GPIO3 General Purpose I/O controlled by the EZRadio peripheral. May be configured through the EZRadio registers to perform various functions including: Clock Output, FIFO status, POR, Wake-Up Timer, TRSW, AntDiversity control, etc. See the EZRadio GPIO Configuration Registers for more information. 12 RXP EZRadio peripheral differential RF input pins of the LNA. See application schematic for example matching network. 13 RXN EZRadio peripheral differential RF input pins of the LNA. See application schematic for example matching network. 14 TX EZRadio peripheral transmit RF output pin. The PA output is an open-drain connection so the L-C match must supply 1.8 to 3.6 VDC to this pin. 15 GND_RF Required ground for the digital and analog portions of the EZRadio peripheral. 16 GND_RF Required ground for the digital and analog portions of the EZRadio peripheral. 17 GND_RF Required ground for the digital and analog portions of the EZRadio peripheral. 18 VDD_RF Power Supply Voltage for the analog portion of the EZRadio peripheral. Must be 1.8 to 3.6 V. 19 NC 20 VDD_RF Crystal Oscillator Output. Crystal Oscillator Input. No bias required, but if used should be set to 0.7V. Also used for external TCXO input. Required ground for the digital and analog portions of the EZRadio peripheral. No Connect Power Supply Voltage for the analog portion of the EZRadio peripheral. Must be 1.8 to 3.6 V. Rev. 1.0 31 Si106x/108x Table 3.3. Si1064/Si1065/Si1084/Si1085 Pin Definitions (Continued) Pin Designation Description 21 GPIO0 General Purpose I/O controlled by the EZRadio peripheral. May be configured through the EZRadio registers to perform various functions including: Clock Output, FIFO status, POR, Wake-Up Timer, TRSW, AntDiversity control, etc. See the EZRadio GPIO Configuration Registers for more information. 22 GPIO1 General Purpose I/O controlled by the EZRadio peripheral. May be configured through the EZRadio registers to perform various functions including: Clock Output, FIFO status, POR, Wake-Up Timer, TRSW, AntDiversity control, etc. See the EZRadio GPIO Configuration Registers for more information. 23 IRQ 24 P0.6/ CNVSTR Port 0.6. See Port I/O section for a complete description. External Convert Start Input for ADC0. See ADC0 section for a complete description. 25 P0.5/RX Port 0.5. See Port I/O section for a complete description. UART RX Pin. See Port I/O section. 26 P0.4/TX Port 0.4. See Port I/O section for a complete description. UART TX Pin. See Port I/O section. 27 P0.3/XTAL2 Port 0.3. See Port I/O Section for a complete description. External Clock Output. This pin is the excitation driver for an external crystal or resonator. External Clock Input. This pin is the external clock input in external CMOS clock mode. External Clock Input. This pin is the external clock input in capacitor or RC oscillator configurations. See Oscillator section for complete details. 28 P0.2/XTAL1 Port 0.2. See Port I/O Section for a complete description. External Clock Input. This pin is the external oscillator return for a crystal or resonator. See Oscillator section. 29 P0.1/AGND Port 0.1. See Port I/O Section for a complete description. Optional Analog ground. See VREF chapter. 30 P0.0/VREF Port 0.0. See Port I/O section for a complete description. External VREF Input. Internal VREF Output. External VREF decoupling capacitors are recommended. See Voltage Reference section. 31 GND_MCU/ DC- DC-DC converter return current path. In single-cell battery mode, this pin is typically not connected to ground. In dual-cell battery mode, this pin must be connected directly to ground. 32 GND_MCU/ VBAT- Required ground for the entire MCU except for the EZRadio peripheral. 32 EZRadio peripheral interrupt status pin. Will be set low to indicate a pending EZRadio interrupt event. See the EZRadio Control Logic Registers for more details. This pin is an open-drain output with a 220 k internal pullup resistor. An external pull-up resistor is recommended. Rev. 1.0 Si106x/108x Table 3.3. Si1064/Si1065/Si1084/Si1085 Pin Definitions (Continued) Pin Designation Description 33 VDD_MCU/ DC+ Power Supply Voltage. Must be 1.8 to 3.6 V. This supply voltage is not required in low power sleep mode. This voltage must always be > VBAT. Positive output of the dc-dc converter. In single-cell battery mode, a 1 F ceramic capacitor is required between DC+ and DC-. This pin can supply power to external devices when operating in single-cell battery mode. 34 DCEN DC-DC Enable Pin. In single-cell battery mode, this pin must be connected to VBAT through a 0.68 H inductor. In dual-cell battery mode, this pin must be connected directly to ground. 35 VBAT+ Battery Supply Voltage. Must be 0.9 to 1.8 V in single-cell battery mode and 1.8 to 3.6 V in dual-cell battery mode. 36 RST/C2CK Device Reset. Open-drain output of internal POR or VDD monitor. An external source can initiate a system reset by driving this pin low for at least 15 s. A 1-5 k pullup to VDD_MCU is recommended. See Reset Sources section for a complete description. Clock signal for the C2 Debug Interface. Rev. 1.0 33 RST/C2CK NC NC VDD_MCU NC GND_MCU P0.0/VREF P0.1/AGND 36 35 34 33 32 31 30 29 Si106x/108x P2.7/C2D 1 28 P0.2/XTAL1 XTAL4 2 27 P0.3/XTAL2 XTAL3 3 26 P0.4/TX P1.6 4 25 P0.5/RX P1.5 5 24 P0.6/CNVSTR P1.4 6 23 IRQ XOUT 7 22 GPIO1 XIN 8 21 GPIO0 GND_RF 9 20 VDD_RF 19 TXRAMP Si1060/Si1061 Si1080/Si1081 (Top View) GND_RF 11 12 13 14 15 16 17 18 RXP RXN GND_RF GND_RF TX GND_RF VDD_RF 10 GPIO3 GPIO2 Figure 3.1. Si1060/1, Si1080/1-A-GM Pinout Diagram (Top View) Rev. 1.0 34 RST/C2CK VBAT+ DCEN VDD_MCU/DC+ GND_MCU/VBAT- GND_MCU/DC- P0.0/VREF P0.1/AGND 36 35 34 33 32 31 30 29 Si106x/108x P2.7/C2D 1 28 P0.2/XTAL1 XTAL4 2 27 P0.3/XTAL2 XTAL3 3 26 P0.4/TX P1.6 4 25 P0.5/RX P1.5 5 24 P0.6/CNVSTR P1.4 6 23 IRQ XOUT 7 22 GPIO1 XIN 8 21 GPIO0 GND_RF 9 20 VDD_RF 19 TXRAMP Si1062/Si1063 Si1082/Si1083 (Top View) GND_RF 16 17 18 GND_RF VDD_RF 14 TX GND_RF 13 RXN 15 12 RXP GND_RF 11 10 GPIO3 GPIO2 Figure 3.2. Si1062/3, Si1082/3-A-GM Pinout Diagram (Top View) 35 Rev. 1.0 RST/C2CK VBAT+ DCEN VDD_MCU/DC+ GND_MCU/VBAT- GND_MCU/DC- P0.0/VREF P0.1/AGND 36 35 34 33 32 31 30 29 Si106x/108x P2.7/C2D 1 28 P0.2/XTAL1 XTAL4 2 27 P0.3/XTAL2 XTAL3 3 26 P0.4/TX P1.6 4 25 P0.5/RX P1.5 5 24 P0.6/CNVSTR P1.4 6 23 IRQ XOUT 7 22 GPIO1 XIN 8 21 GPIO0 GND_RF 9 20 VDD_RF 19 NC Si1064/Si1065 Si1084/Si1085 (Top View) GND_RF 11 12 13 14 15 16 17 18 RXP RXN TX GND_RF GND_RF GND_RF VDD_RF 10 GPIO3 GPIO2 Figure 3.3. Si1064/5, Si1084/5-A-GM Pinout Diagram (Top View) Rev. 1.0 36 Si106x/108x Figure 3.4. QFN-36 Package Drawing 37 Rev. 1.0 Si106x/108x Table 3.4. QFN-36 Package Dimensions Dimension Min Nom Max A 0.70 0.75 0.80 A1 0.00 0.02 0.05 b 0.20 0.25 0.30 D D2 5.00 BSC 3.55 3.60 e 0.50 BSC E 6.00 BSC 3.65 E2 4.05 4.10 4.15 L 0.30 0.40 0.50 aaa -- -- 0.10 bbb -- -- 0.10 ccc -- -- 0.08 ddd -- -- 0.10 Notes: 1. All dimensions shown are in millimeters (mm) unless otherwise noted. 2. Dimensioning and Tolerancing per ANSI Y14.5M-1994. 3. This drawing conforms to the JEDEC Solid State Outline MO-220, Variation VHJD. Rev. 1.0 38 Si106x/108x Figure 3.5. QFN-36 PCB Land Pattern Dimensions 39 Rev. 1.0 Si106x/108x Table 3.5. QFN-36 PCB Land Pattern Dimensions Dimension mm C1 4.90 C2 5.90 E 0.50 X1 0.30 Y1 0.85 X2 3.65 Y2 4.15 Notes: General 1. All dimensions shown are at Maximum Material Condition (MMC). Least Material Condition (LMC) is calculated based on a Fabrication Allowance of 0.05 mm. 2. This Land Pattern Design is based on the IPC-7351 guidelines. Solder Mask Design 3. All metal pads are to be non-solder mask defined (NSMD). Clearance between the solder mask and the metal pad is to be 60 m minimum, all the way around the pad. Stencil Design 4. A stainless steel, laser-cut and electro-polished stencil with trapezoidal walls should be used to assure good solder paste release. 5. The stencil thickness should be 0.125 mm (5 mils). 6. The ratio of stencil aperture to land pad size should be 1:1 for all perimeter pins. 7. A 2x2 array of 1.550 mm x 1.300 mm square openings on 1.05 mm pitch should be used for the center ground pad. Card Assembly 8. A No-Clean, Type-3 solder paste is recommended. 9. The recommended card reflow profile is per the JEDEC/IPC J-STD-020 specification for Small Body Components. Rev. 1.0 40 1.756 1.756 Si106x/108x O0.250 1.506 1.506 Center pad paste detail: R 0.250 1.550 1.300 Figure 3.6. QFN-36 PCB Stencil and Via Placement 41 Rev. 1.0 Si106x/108x 4. Electrical Characteristics In sections 4.1 and 4.2, "VDD" refers to the VDD_MCU supply voltage on Si1060/1, Si1080/1 devices and to the VDD_MCU/DC+ supply voltage on Si1062/3/4/5, Si1082/3/4/5 devices. The ADC, Comparator, and Port I/O specifications in these two sections do not apply to the radio peripheral. In section 4.3, "VDD" refers to the VDD_RF Supply Voltage. All specifications in these sections pertain to the radio peripheral. 4.1. Absolute Maximum Specifications Table 4.1. Absolute Maximum Ratings Parameter Test Condition Min Typ Max Unit -65 -- 150 C VDD > 2.2 V VDD < 2.2 V -0.3 -0.3 -- -- 5.8 VDD + 3.6 V One-Cell Mode Two-Cell Mode -0.3 -0.3 -- -- 2.0 4.0 V -0.3 -- 4.0 V Maximum Total Current through VBAT, DCEN, VDD_MCU/DC+ or GND -- -- 500 mA Maximum Output Current Sunk by RST or any Px.x Pin -- -- 100 mA Maximum Total Current through all Px.x Pins -- -- 200 mA DC-DC Converter Output Power -- -- 110 mW All pins except TX, RXp, and RXn -- -- 2 kV TX, RXp, and RXn -- -- 1 kV All pins except TX, RXp, and RXn -- -- 150 V TX, RXp, and RXn -- -- 45 V Storage Temperature Voltage on any Px.x I/O Pin or RST with Respect to GND Voltage on VBAT with respect to GND Voltage on VDD_MCU or VDD_MCU/DC+ with respect to GND ESD (Human Body Model) ESD (Machine Model) Note: 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 devices 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. Rev. 1.0 42 Si106x/108x 4.2. MCU Electrical Characteristics Table 4.2. Global Electrical Characteristics -40 to +85 C, 25 MHz system clock unless otherwise specified. See "AN358: Optimizing Low Power Operation of the `F9xx" for details on how to achieve the supply current specifications listed in this table. Parameter Test Condition Min Typ Max Unit Battery Supply Voltage (VBAT) One-Cell Mode Two-Cell Mode 0.9 1.8 1.2 2.4 1.8 3.6 V Supply Voltage (VDD_MCU/DC+) One-Cell Mode Two-Cell Mode 1.8 1.8 1.9 2.4 3.6 3.6 V VDD (not in Sleep Mode) VBAT (in Sleep Mode) -- -- 1.4 0.3 -- 0.5 V SYSCLK (System Clock)2 0 -- 25 MHz TSYSH (SYSCLK High Time) 18 -- -- ns TSYSL (SYSCLK Low Time) 18 -- -- ns Specified Operating Temperature Range -40 -- +85 C Minimum RAM Data Retention Voltage1 Digital Supply Current--CPU Active (Normal Mode, fetching instructions from flash) IDD 3, 4, 5, 6, 7, 8 IDD Frequency Sensitivity3, 5, 6, 7. 8 43 VDD = 1.8-3.6 V, F = 24.5 MHz (includes precision oscillator current) -- 4.1 5.0 mA VDD = 1.8-3.6 V, F = 20 MHz (includes low power oscillator current) -- 3.5 -- mA VDD = 1.8 V, F = 1 MHz VDD = 3.6 V, F = 1 MHz (includes external oscillator/GPIO current) -- -- 295 365 -- -- A A VDD = 1.8-3.6 V, F = 32.768 kHz (includes SmaRTClock oscillator current) -- 90 -- A VDD = 1.8-3.6 V, T = 25 C, F < 10 MHz (flash oneshot active, see 12.6) -- 226 -- A/MHz VDD = 1.8-3.6 V, T = 25 C, F > 10 MHz (flash oneshot bypassed, see 12.6) -- 120 -- A/MHz Rev. 1.0 Si106x/108x Table 4.2. Global Electrical Characteristics (Continued) -40 to +85 C, 25 MHz system clock unless otherwise specified. See "AN358: Optimizing Low Power Operation of the `F9xx" for details on how to achieve the supply current specifications listed in this table. Parameter Test Condition Min Typ Max Unit Digital Supply Current--CPU Inactive (Idle Mode, not fetching instructions from flash) IDD4, 6,7,8 IDD Frequency Sensitivity1,6,8 VDD = 1.8-3.6 V, F = 24.5 MHz (includes precision oscillator current) -- 2.5 3.0 mA VDD = 1.8-3.6 V, F = 20 MHz (includes low power oscillator current) -- 1.8 -- mA VDD = 1.8 V, F = 1 MHz VDD = 3.6 V, F = 1 MHz (includes external oscillator/GPIO current) -- -- 165 235 -- -- A A VDD = 1.8-3.6 V, F = 32.768 kHz (includes SmaRTClock oscillator current) -- 84 -- A VDD = 1.8-3.6 V, T = 25 C -- 95 -- A/MHz -- 77 -- A Digital Supply Current--Suspend and Sleep Mode Digital Supply Current6,7,8 (Suspend Mode) VDD = 1.8-3.6 V, two-cell mode Digital Supply Current8 (Sleep Mode, SmaRTClock running) 1.8 V, T = 25 C 3.0 V, T = 25 C 3.6 V, T = 25 C 1.8 V, T = 85 C 3.0 V, T = 85 C 3.6 V, T = 85 C (includes SmaRTClock oscillator and brownout detector) -- -- -- -- -- -- 0.61 0.76 0.87 1.32 1.62 1.93 -- -- -- -- -- -- A Digital Supply Current8 (Sleep Mode) 1.8 V, T = 25 C 3.0 V, T = 25 C 3.6 V, T = 25 C 1.8 V, T = 85 C 3.0 V, T = 85 C 3.6 V, T = 85 C (includes brownout detector) -- -- -- -- -- -- 0.06 0.09 0.14 0.77 0.92 1.23 -- -- -- -- -- -- A Rev. 1.0 44 Si106x/108x Table 4.2. Global Electrical Characteristics (Continued) -40 to +85 C, 25 MHz system clock unless otherwise specified. See "AN358: Optimizing Low Power Operation of the `F9xx" for details on how to achieve the supply current specifications listed in this table. Parameter Test Condition Min Typ Max Unit Notes: 1. Based on device characterization data; Not production tested. 2. SYSCLK must be at least 32 kHz to enable debugging. 3. Digital Supply Current depends upon the particular code being executed. The values in this table are obtained with the CPU executing an "sjmp $" loop, which is the compiled form of a while(1) loop in C. One iteration requires 3 CPU clock cycles, and the flash memory is read on each cycle. The supply current will vary slightly based on the physical location of the sjmp instruction and the number of flash address lines that toggle as a result. In the worst case, current can increase by up to 30% if the sjmp loop straddles a 128-byte flash address boundary (e.g., 0x007F to 0x0080). Real-world code with larger loops and longer linear sequences will have few transitions across the 128-byte address boundaries. 4. Includes oscillator and regulator supply current. 5. IDD can be estimated for frequencies <10 MHz by simply multiplying the frequency of interest by the frequency sensitivity number for that range, then adding an offset of 90 A. When using these numbers to estimate IDD for >10 MHz, the estimate should be the current at 25 MHz minus the difference in current indicated by the frequency sensitivity number. For example: VDD = 3.0 V; F = 20 MHz, IDD = 4.1 mA - (25 MHz - 20 MHz) x 0.120 mA/MHz = 3.5 mA. 6. The Supply Voltage is the voltage at the VDD_MCU pin, typically 1.8 to 3.6 V (default = 1.9 V). Idle IDD can be estimated by taking the current at 25 MHz minus the difference in current indicated by the frequency sensitivity number. For example: VDD = 3.0 V; F = 5 MHz, Idle IDD = 2.5 mA - (25 MHz - 5 MHz) x 0.095 mA/MHz = 0.6 mA. 7. The supply current specifications in Table 4.2 are for two cell mode. The VBAT current in one-cell mode can be estimated using the following equation: Supply Voltage Supply Current (two-cell mode) VBAT Current (one-cell mode) = ----------------------------------------------------------------------------------------------------------------------------------DC-DC Converter Efficiency VBAT Voltage The VBAT Voltage is the voltage at the VBAT pin, typically 0.9 to 1.8 V. The Supply Current (two-cell mode) is the data sheet specification for supply current. The Supply Voltage is the voltage at the VDD/DC+ pin, typically 1.8 to 3.3 V (default = 1.9 V). The DC-DC Converter Efficiency can be estimated using Figure 4.3-Figure 4.5. 8. The radio peripheral is placed in Shutdown mode. 45 Rev. 1.0 Si106x/108x 4200 4100 F < 10 MHz Oneshot Enabled 4000 3900 F > 10 MHz Oneshot Bypassed 3800 3700 3600 3500 3400 < 170 A/MHz 3300 3200 3100 3000 2900 200 A/MHz 2800 2700 2600 215 A/MHz Supply Current (uA) 2500 2400 2300 2200 2100 2000 1900 1800 1700 1600 1500 1400 240 A/MHz 1300 1200 1100 1000 900 800 250 A/MHz 700 600 500 400 300 300 A/MHz 200 100 0 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 Frequency (MHz) Figure 4.1. Active Mode Current (External CMOS Clock) Rev. 1.0 46 Si106x/108x Supply Current vs. Frequency 4200 4100 4000 3900 3800 3700 3600 3500 3400 3300 3200 3100 3000 2900 2800 2700 2600 Supply Current (uA) 2500 2400 2300 2200 2100 2000 1900 1800 1700 1600 1500 1400 1300 1200 1100 1000 900 800 700 600 500 400 300 200 100 0 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 Frequency (MHz) Figure 4.2. Idle Mode Current (External CMOS Clock) 47 Rev. 1.0 21 22 23 24 25 Si106x/108x 6:6(/ 6:6(/ Efficiency (%) 9%$7 9 9%$7 9 9%$7 9 9%$7 9 9%$7 9 9%$7 9 9%$7 9 X+,QGXFWRUSDFNDJH(65 2KPV 9'''& 90LQLPXP3XOVH:LGWK QV 3XOVH6NLSSLQJ'LVDEOHG 1RWH(IILFLHQF\DWKLJKFXUUHQWVPD\EHLPSURYHGE\FKRRVLQJDQ LQGXFWRUZLWKDORZHU(65 Load Current (mA) Figure 4.3. Typical DC-DC Converter Efficiency (High Current, VDD/DC+ = 2 V Rev. 1.0 48 Si106x/108x 6:6(/ 6:6(/ 9%$7 9 Efficiency (%) 9%$7 9 9%$7 9 9%$7 9 9%$7 9 9%$7 9 9%$7 9 X+,QGXFWRUSDFNDJH(65 2KPV 9'''& 90LQLPXP3XOVH:LGWK QV 3XOVH6NLSSLQJ'LVDEOHG 1RWH(IILFLHQF\DWKLJKFXUUHQWVPD\EHLPSURYHGE\ FKRRVLQJDQLQGXFWRUZLWKDORZHU(65 Load current (mA) Figure 4.4. Typical DC-DC Converter Efficiency (High Current, VDD/DC+ = 3 V) 49 Rev. 1.0 Si106x/108x 9%$7 9 9%$7 9 Efficiency (%) 9%$7 9 9%$7 9 9%$7 9 9%$7 9 9%$7 9 X+,QGXFWRUSDFNDJH(65 2KPV 6:6(/ 9'''& 90LQLPXP3XOVH:LGWK QV Load current (mA) Figure 4.5. Typical DC-DC Converter Efficiency (Low Current, VDD/DC+ = 2 V) Rev. 1.0 50 Si106x/108x X+,QGXFWRUSDFNDJH(65 2KPV 6:6(/ 9'''& 9/RDG&XUUHQW X$ 0LQ3XOVH:LGWKQV 0LQ3XOVH:LGWKQV 0LQ3XOVH:LGWKQV 0LQ3XOVH:LGWKQV 9%$7&XUUHQW X$ 9%$7 9 Figure 4.6. Typical One-Cell Suspend Mode Current 51 Rev. 1.0 Si106x/108x Table 4.3. Port I/O DC Electrical Characteristics VDD = 1.8 to 3.6 V, -40 to +85 C unless otherwise specified. Parameters Test Condition Output High Voltage High Drive Strength, PnDRV.n = 1 IOH = -3 mA, Port I/O push-pull IOH = -10 A, Port I/O push-pull IOH = -10 mA, Port I/O push-pull Low Drive Strength, PnDRV.n = 0 IOH = -1 mA, Port I/O push-pull IOH = -10 A, Port I/O push-pull IOH = -3 mA, Port I/O push-pull Min Typ Max VDD - 0.7 VDD - 0.1 -- -- See Chart -- -- VDD - 0.7 -- VDD - 0.1 -- -- See Chart -- -- -- Unit V Output Low Voltage High Drive Strength, PnDRV.n = 1 IOL = 8.5 mA IOL = 10 A IOL = 25 mA -- -- -- -- -- See Chart 0.6 0.1 -- Low Drive Strength, PnDRV.n = 0 IOL = 1.4 mA IOL = 10 A IOL = 4 mA -- -- -- -- -- See Chart 0.6 0.1 -- VDD = 2.0 to 3.6 V VDD - 0.6 -- -- V VDD = 0.9 to 2.0 V 0.7 x VDD -- -- V VDD = 2.0 to 3.6 V -- -- 0.6 V VDD = 0.9 to 2.0 V -- -- 0.3 x VDD V Weal Pullup Off Weak Pullup On, VIN = 0 V, VDD = 1.8 V Weak Pullup On, Vin = 0 V, VDD = 3.6 V -- -- -- -- 4 20 1 -- 35 A Input High Voltage Input Low Voltage Input Leakage Current Rev. 1.0 V 52 Si106x/108x Typical VOH (High Drive Mode) Voltage 3.6 3.3 VDD = 3.6V 3 VDD = 3.0V 2.7 VDD = 2.4V 2.4 VDD = 1.8V 2.1 1.8 1.5 1.2 0.9 0 5 10 15 20 25 30 35 40 45 50 Load Current (mA) Typical VOH (Low Drive Mode) Voltage 3.6 3.3 VDD = 3.6V 3 VDD = 3.0V 2.7 VDD = 2.4V 2.4 VDD = 1.8V 2.1 1.8 1.5 1.2 0.9 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 Load Current (mA) Figure 4.7. Typical VOH Curves, 1.8-3.6 V 53 Rev. 1.0 Si106x/108x Typical VOH (High Drive Mode) 1.8 VDD = 1.8V 1.7 1.6 VDD = 1.5V 1.5 1.4 VDD = 1.2V Voltage 1.3 VDD = 0.9V 1.2 1.1 1 0.9 0.8 0.7 0.6 0.5 0 1 2 3 4 5 6 7 8 9 10 11 12 Load Current (mA) Typical VOH (Low Drive Mode) 1.8 1.7 VDD = 1.8V 1.6 VDD = 1.5V 1.5 1.4 VDD = 1.2V Voltage 1.3 1.2 VDD = 0.9V 1.1 1 0.9 0.8 0.7 0.6 0.5 0 1 2 3 Load Current (mA) Figure 4.8. Typical VOH Curves, 0.9-1.8 V Rev. 1.0 54 Si106x/108x Typical VOL (High Drive Mode) 1.8 VDD = 3.6V 1.5 VDD = 3.0V Voltage 1.2 VDD = 2.4V VDD = 1.8V 0.9 0.6 0.3 0 -80 -70 -60 -50 -40 -30 -20 -10 0 Load Current (mA) Typical VOL (Low Drive Mode) 1.8 VDD = 3.6V 1.5 VDD = 3.0V Voltage 1.2 VDD = 2.4V VDD = 1.8V 0.9 0.6 0.3 0 -10 -9 -8 -7 -6 -5 -4 -3 -2 -1 0 Load Current (mA) Figure 4.9. Typical VOL Curves, 1.8-3.6 V 55 Rev. 1.0 Si106x/108x Typical VOL (High Drive Mode) 0.5 VDD = 1.8V Voltage 0.4 VDD = 1.5V VDD = 1.2V 0.3 VDD = 0.9V 0.2 0.1 0 -5 -4 -3 -2 -1 0 Load Current (mA) Typical VOL (Low Drive Mode) 0.5 Voltage 0.4 0.3 VDD = 1.8V 0.2 VDD = 1.5V VDD = 1.2V 0.1 VDD = 0.9V 0 -3 -2 -1 0 Load Current (mA) Figure 4.10. Typical VOL Curves, 0.9-1.8 V Rev. 1.0 56 Si106x/108x Table 4.4. Reset Electrical Characteristics VDD = 1.8 to 3.6 V, -40 to +85 C unless otherwise specified. Parameter Test Condition Min Typ Max Unit RST Output Low Voltage IOL = 1.4 mA, -- -- 0.6 V RST Input High Voltage VDD = 2.0 to 3.6 V VDD - 0.6 -- -- V VDD = 0.9 to 2.0 V 0.7 x VDD -- -- V VDD = 2.0 to 3.6 V -- -- 0.6 V VDD = 0.9 to 2.0 V -- -- 0.3 x VDD V RST = 0.0 V, VDD = 1.8 V RST = 0.0 V, VDD = 3.6 V -- -- 4 20 -- 35 A Early Warning Reset Trigger (all power modes except Sleep) 1.8 1.7 1.85 1.75 1.9 1.8 V VDD Ramp Time for Power On One-cell Mode: VBAT Ramp 0-0.9 V Two-cell Mode: VBAT Ramp 0-1.8 V -- -- 3 ms VDD Monitor Threshold (VPOR) Initial Power-On (VDD Rising) Brownout Condition (VDD Falling) Recovery from Brownout (VDD Rising) -- 0.7 -- 0.75 0.8 0.95 -- 0.9 -- V Missing Clock Detector Timeout Time from last system clock rising edge to reset initiation 100 650 1000 s Minimum System Clock w/ Missing Clock Detector Enabled System clock frequency which triggers a missing clock detector timeout -- 7 10 kHz Delay between release of any reset source and code execution at location 0x0000 -- 10 -- s Minimum RST Low Time to Generate a System Reset 15 -- -- s VDD Monitor Turn-on Time -- 300 -- ns VDD Monitor Supply Current -- 7 -- A RST Input Low Voltage RST Input Pullup Current VDD_MCU Monitor Threshold (VRST) Reset Time Delay 57 Rev. 1.0 Si106x/108x Table 4.5. Power Management Electrical Specifications VDD = 1.8 to 3.6 V, -40 to +85 C unless otherwise specified. Parameter Test Condition Min Typ Max Unit 2 -- 3 SYSCLKs Low power oscillator -- 400 -- ns Precision oscillator -- 1.3 -- s Two-cell mode -- 2 -- s One-cell mode -- 10 -- s Idle Mode Wake-up Time Suspend Mode Wake-up Time Sleep Mode Wake-up Time Table 4.6. Flash Electrical Characteristics VDD = 1.8 to 3.6 V, -40 to +85 C unless otherwise specified. Parameter Test Condition Min Typ Max Unit Si1060, Si1062, Si1064 65536 -- -- bytes Si1061, Si1063, Si1065 32768 -- -- bytes Si1080, Si1082, Si1084 16384 -- -- bytes Si1081, Si1083, Si1085 8192 -- -- bytes Si1060-Si1065 1024 -- 1024 bytes Si1080-Si1085 512 -- 512 bytes Endurance 1k 30k -- Erase/Write Cycles Erase Cycle Time 28 32 36 ms Write Cycle Time 57 64 71 s Flash Size Scratchpad Size Notes: 1. 1024 bytes at addresses 0xFC00 to 0xFFFF are reserved. 2. 1024 bytes at addresses 0x3C00 to 0x3FFF are reserved. Rev. 1.0 58 Si106x/108x Table 4.7. Internal Precision Oscillator Electrical Characteristics VDD = 1.8 to 3.6 V; TA = -40 to +85 C unless otherwise specified; Using factory-calibrated settings. Parameter Test Condition Oscillator Frequency Oscillator Supply Current (from VDD) 25 C; includes bias current of 90-100 A Min Typ Max Unit 24 24.5 25 MHz -- 300* -- A *Note: Does not include clock divider or clock tree supply current. Table 4.8. Internal Low-Power Oscillator Electrical Characteristics VDD = 1.8 to 3.6 V; TA = -40 to +85 C unless otherwise specified; Using factory-calibrated settings. Parameter Test Condition Oscillator Frequency Oscillator Supply Current (from VDD) 25 C No separate bias current required. *Note: Does not include clock divider or clock tree supply current. 59 Rev. 1.0 Min Typ Max Unit 18 20 22 MHz -- 100* -- A Si106x/108x Table 4.9. ADC0 Electrical Characteristics VDD = 1.8 to 3.6V V, VREF = 1.65 V (REFSL[1:0] = 11), -40 to +85 C unless otherwise specified. Parameter Test Condition Min Typ Max Unit DC Accuracy Resolution 10 Integral Nonlinearity bits -- 0.5 1 LSB -- 0.5 1 LSB Offset Error -- <1 2 LSB Full Scale Error -- 1 2.5 LSB Differential Nonlinearity Guaranteed Monotonic Dynamic performance (10 kHz sine-wave single-ended input, 1 dB below Full Scale, 300 ksps) Signal-to-Noise Plus Distortion 54 58 -- dB Signal-to-Distortion -- 73 -- dB Spurious-Free Dynamic Range -- 75 -- dB -- -- 7.33 MHz 13 11 -- -- -- -- clocks Track/Hold Acquisition Time 1.5 -- -- us Throughput Rate -- -- 300 ksps Single Ended (AIN+ - GND) 0 -- VREF V Single Ended 0 -- VDD V 1x Gain 0.5x Gain -- 30 28 -- pF -- 5 -- k Conversion Rate SAR Conversion Clock Conversion Time in SAR Clocks 10-bit Mode 8-bit Mode Analog Inputs ADC Input Voltage Range Absolute Pin Voltage with respect to GND Sampling Capacitance Input Multiplexer Impedance Power Specifications Power Supply Current (VDD supplied to ADC0) Conversion Mode (300 ksps) Tracking Mode (0 ksps) -- -- 800 680 -- -- A Power Supply Rejection Internal High Speed VREF External VREF -- -- 67 74 -- -- dB Rev. 1.0 60 Si106x/108x Table 4.10. Temperature Sensor Electrical Characteristics VDD = 1.8 to 3.6V V, -40 to +85 C unless otherwise specified. Parameter Test Condition Linearity Slope Slope Error 1 Min Typ Max Unit -- 1 -- C -- 3.40 -- mV/C -- 40 -- V/C Offset Temp = 25 C -- 1025 -- mV Offset Error1 Temp = 25 C -- 18 -- mV Initial Voltage=0 V Initial Voltage=3.6 V -- -- 3.0 6.5 s -- 35 -- A Temperature Sensor Settling Time2 Supply Current Notes: 1. Represents one standard deviation from the mean. 2. The temperature sensor settling time is guaranteed by characterization. The temperature sensor settling time, resulting from an ADC mux change or enabling of the temperature sensor, varies with the voltage of the previously sampled channel and can be up to 6.5 s if the previously sampled channel voltage was greater than 3 V. To minimize the temperature sensor settling time, the ADC mux can be momentarily set to ground before being set to the temperature sensor output. This ensures that the temperature sensor output will settle in 3 s or less. 61 Rev. 1.0 Si106x/108x Table 4.11. Voltage Reference Electrical Characteristics VDD = 1.8 to 3.6 V, -40 to +85 C unless otherwise specified. Parameter Test Condition Internal High-Speed Reference (REFSL[1:0] = 11) -40 to +85 C, Output Voltage VDD = 1.8-3.6 V VREF Turn-on Time* Supply Current Internal Precision Reference (REFSL[1:0] = 00, REFOE = 1) -40 to +85 C, Output Voltage VDD = 1.8-3.6 V VREF Short-Circuit Current Load = 0 to 200 A to AGND Load Regulation VREF Turn-on Time 1 VREF Turn-on Time 2 VREF Turn-on Time 3 4.7 F tantalum, 0.1 F ceramic bypass, settling to 0.5 LSB 0.1 F ceramic bypass, settling to 0.5 LSB no bypass cap, settling to 0.5 LSB Supply Current Min Typ Max Unit 1.60 1.65 1.70 V -- -- 1.7 s -- 200 -- A 1.645 1.680 1.715 V -- 3.5 -- mA -- 400 -- V/A -- 15 -- ms -- 300 -- s -- 25 -- s -- 15 -- A 0 -- VDD V -- 5.25 -- A External Reference (REFSL[1:0] = 00, REFOE = 0) Input Voltage Range Input Current Sample Rate = 300 ksps; VREF = 3.0 V *Note: Guaranteed by characterization. Rev. 1.0 62 Si106x/108x Table 4.12. Comparator Electrical Characteristics VDD = 1.8 to 3.6 V, -40 to +85 C unless otherwise noted. Parameter Test Condition Min Typ Max Unit Response Time: Mode 0, VDD = 2.4 V, VCM* = 1.2 V CP0+ - CP0- = 100 mV -- 130 -- ns CP0+ - CP0- = -100 mV -- 200 -- ns CP0+ - CP0- = 100 mV -- 210 -- ns CP0+ - CP0- = -100 mV -- 410 -- ns CP0+ - CP0- = 100 mV -- 420 -- ns CP0+ - CP0- = -100 mV -- 1200 -- ns CP0+ - CP0- = 100 mV -- 1750 -- ns CP0+ - CP0- = -100 mV -- 6200 -- ns Common-Mode Rejection Ratio -- 1.5 4 mV/V Inverting or Non-Inverting Input Voltage Range -0.25 -- VDD + 0.25 V Input Capacitance -- 12 -- pF Input Bias Current -- 1 -- nA Input Offset Voltage -7 -- +7 mV -- 0.1 -- mV/V VDD = 3.6 V -- 0.6 -- s VDD = 3.0 V -- 1.0 -- s VDD = 2.4 V -- 1.8 -- s VDD = 1.8 V -- 10 -- s Mode 0 -- 23 -- A Mode 1 -- 8.8 -- A Mode 2 -- 2.6 -- A Mode 3 -- 0.4 -- A Response Time: Mode 1, VDD = 2.4 V, VCM* = 1.2 V Response Time: Mode 2, VDD = 2.4 V, VCM* = 1.2 V Response Time: Mode 3, VDD = 2.4 V, VCM* = 1.2 V Power Supply Power Supply Rejection Power-up Time Supply Current at DC Note: Vcm is the common-mode voltage on CP0+ and CP0-. 63 Rev. 1.0 Si106x/108x Table 4.12. Comparator Electrical Characteristics VDD = 1.8 to 3.6 V, -40 to +85 C unless otherwise noted. Parameter Test Condition Min Typ Max Unit Hysteresis 1 (CPnHYP/N1-0 = 00) -- 0 -- mV Hysteresis 2 (CPnHYP/N1-0 = 01) -- 8.5 -- mV Hysteresis 3 (CPnHYP/N1-0 = 10) -- 17 -- mV Hysteresis 4 (CPnHYP/N1-0 = 11) -- 34 -- mV Hysteresis 1 (CPnHYP/N1-0 = 00) -- 0 -- mV Hysteresis 2 (CPnHYP/N1-0 = 01) -- 6.5 -- mV Hysteresis 3 (CPnHYP/N1-0 = 10) -- 13 -- mV Hysteresis 4 (CPnHYP/N1-0 = 11) -- 26 -- mV Hysteresis 1 (CPnHYP/N1-0 = 00) -- 0 1 mV Hysteresis 2 (CPnHYP/N1-0 = 01) 2 5 10 mV Hysteresis 3 (CPnHYP/N1-0 = 10) 5 10 20 mV Hysteresis 4 (CPnHYP/N1-0 = 11) 12 20 30 mV Hysteresis 1 (CPnHYP/N1-0 = 00) -- 0 -- mV Hysteresis 2 (CPnHYP/N1-0 = 01) -- 4.5 -- mV Hysteresis 3 (CPnHYP/N1-0 = 10) -- 9 -- mV Hysteresis 4 (CPnHYP/N1-0 = 11) -- 17 -- mV Hysteresis Mode 0 Mode 1 Mode 2 Mode 3 Note: Vcm is the common-mode voltage on CP0+ and CP0-. Rev. 1.0 64 Si106x/108x Table 4.13. DC-DC Converter (DC0) Electrical Characteristics VBAT = 0.9 to 1.8 V, -40 to +85 C unless otherwise specified. Parameter Test Condition Min Typ Max Unit Input Voltage Range 0.9 -- 1.8 V Input Inductor Value 500 680 900 nH Input Inductor Current Rating 250 -- -- mA -- -- 0.5 -- -- 4.7 1.0 -- -- F Source Impedance < 2 Target Output = 1.8 V 1.73 1.80 1.87 V Target Output = 1.9 V 1.83 1.90 1.97 V Target Output = 2.0 V 1.93 2.00 2.07 V Target Output = 2.1 V 2.03 2.10 2.17 V Target Output = 2.1 V 2.30 2.40 2.50 V Target Output = 2.7 V 2.60 2.70 2.80 V Target Output = 3.0 V 2.90 3.00 3.10 V Target Output = 3.3 V 3.18 3.30 3.42 V Target Output = 2.0 V, 1 to 30 mA -- 0.3 -- % Target Output = 3.0 V, 1 to 20 mA -- 1 -- % Target Output = 1.8 V -- -- 36 mA Target Output = 1.9 V -- -- 34 mA Target Output = 2.0 V -- -- 32 mA Target Output = 2.1 V -- -- 30 mA Target Output = 2.4 V -- -- 27 mA Target Output = 2.7 V -- -- 24 mA Target Output = 3.0 V -- -- 21 mA Target Output = 3.3 V -- -- 19 mA -- -- 65 mW -- -- 80 100 -- -- A Clocking Frequency 1.6 2.4 3.2 MHz Maximum DC Load Current During Startup -- -- 1 mA Capacitance Connected to Output 0.8 1.0 2.0 F Inductor DC Resistance Input Capacitor Value Output Voltage Range Output Load Regulation Output Current (based on output power spec) Output Power Bias Current 65 from VBAT supply from VDD/DC+ supply Rev. 1.0 Si106x/108x Table 4.14. VREG0 Electrical Characteristics VDD = 1.8 to 3.6 V, -40 to +85 C unless otherwise specified. Parameter Test Condition Input Voltage Range Bias Current Normal, Idle, Suspend, or Stop Mode Rev. 1.0 Min Typ Max Unit 1.8 -- 3.6 V -- 20 -- A 66 Si106x/108x 4.3. Radio Electrical Characteristics Table 4.15. DC Characteristics Parameter Symbol Test Condition Min Typ Max Unit 1.8 3.3 3.6 V Supply Voltage Range VDD Power Saving Modes IShutdown RC Oscillator, Main Digital Regulator, and Low Power Digital Regulator OFF -- 30 -- nA IStandby Register values maintained and RC oscillator/WUT OFF -- 50 -- nA ISleepRC RC Oscillator/WUT ON and all register values maintained, and all other blocks OFF -- 900 -- nA IReady Crystal Oscillator and Main Digital Regulator ON, all other blocks OFF -- 1.8 -- mA ITune_RX RX Tune, High Performance Mode -- 7.2 -- mA ITune_TX TX Tune, High Performance Mode -- 8 -- mA IRXH High Performance Mode -- 13.7 -- mA IRXL Low Power Mode -- 10.7 -- mA ITX_+20 +20 dBm output power, switched-current match, 915 MHz, 3.3 V -- 85 -- mA +20 dBm output power, switched-current match, 460 MHz, 3.3 V -- 75 -- mA +20 dBm output power, square-wave match, 169 MHz, 3.3 V -- 70 -- mA ITX_+13 +13 dBm output power, switched-current match, 868 MHz, 3.3 V -- 29 -- mA ITX_+10 +10 dBm output power, Class-E match, 868 MHz, 3.3 V -- 18 -- mA TUNE Mode Current RX Mode Current TX Mode Current (Si1060/61, Si1080/81) TX Mode Current (Si1062/63/64/65, Si1082/83/84/85) Rev. 1.0 67 Si106x/108x Table 4.16. Synthesizer AC Electrical Characteristics Parameter Synthesizer Frequency Range (Si1060/61/62/63, Si1080/81/82/83) Synthesizer Frequency Range (Si1064/65, Si1084/85) Synthesizer Frequency Symbol Test Condition FSYN FSYN Min Typ Max Unit 850 -- 1050 MHz 420 -- 525 MHz 284 -- 350 MHz 142 -- 175 MHz 850 -- 960 MHz 425 -- 525 MHz 283 -- 350 MHz FRES-960 850-1050 MHz -- 28.6 -- Hz FRES-525 420-525 MHz -- 14.3 -- Hz FRES-350 283-350 MHz -- 9.5 -- Hz FRES-175 142-175 MHz -- 4.7 -- Hz FRES-960 850-960 MHz -- 114.4 -- Hz FRES-525 425-525 MHz -- 57.2 -- Hz FRES-350 283-350 MHz -- 38.1 -- Hz Synthesizer Settling Time tLOCK Measured from exiting Ready mode with XOSC running to any frequency. Including VCO Calibration. -- 50 -- s Phase Noise L(fM) F = 10 kHz, 460 MHz, High-Performance Mode -- -106 -- dBc/Hz F = 100 kHz, 460 MHz, High-Performance Mode -- -110 -- dBc/Hz F = 1 MHz, 460 MHz, High-Performance Mode -- -123 -- dBc/Hz F = 10 MHz, 460 MHz, High-Performance Mode -- -130 -- dBc/Hz Resolution * (Si1060/61/62/63, Si1080/81/82/83) Synthesizer Frequency Resolution (Si1064/65, Si1084/85) *Note: Default API setting for modulation deviation resolution is double the typical value specified. 68 Rev. 1.0 Si106x/108x Table 4.17. Receiver AC Electrical Characteristics Parameter RX Frequency Range (Si1060/61/62/63, Si1080/81/82/83) RX Frequency Range (Si1064/65, Si1084/85) RX Sensitivity (Si1060/61/62/63, Si1080/81/82/83) Symbol Test Condition FRX FRX Min Typ Max Unit 850 -- 1050 MHz 420 -- 525 MHz 284 -- 350 MHz 142 -- 175 MHz 850 -- 960 MHz 425 -- 525 MHz 283 -- 350 MHz PRX_0.5 (BER < 0.1%) (500 bps, GFSK, BT = 0.5, f = 250Hz) -- -126 -- dBm PRX_40 (BER < 0.1%) (40 kbps, GFSK, BT = 0.5, f = 20 kHz) -- -110 -- dBm PRX_100 (BER < 0.1%) (100 kbps, GFSK, BT = 0.5, f = 50 kHz) -- -106 -- dBm PRX_125 (BER < 0.1%) (125 kbps, GFSK, BT = 0.5, -- -105 -- dBm Df = 62.5 kHz)* PRX_500 (BER < 0.1%) (500 kbps, GFSK, BT = 0.5, f = 250 kHz) -- -97 -- dBm PRX_9.6 (PER 1%) (9.6 kbps, 4GFSK, BT = 0.5, -- -110 -- dBm -- -88 -- dBm f = kHz)* PRX_1M (PER 1%) (1 Mbps, 4GFSK, BT = 0.5, inner deviation = 83.3 kHz)* Notes: 1. For PER tests, 48 preamble symbols, 4 byte sync word, 10 byte payload and CRC-32 was used. PER and BER tested in the 450-470 MHz band. 2. Guaranteed by design. Rev. 1.0 69 Si106x/108x Table 4.17. Receiver AC Electrical Characteristics (Continued) Parameter RX Sensitivity (Si1060/61/62/63, Si1080/81/82/83) Symbol Test Condition Min -- Typ -110 Max -- Unit dBm PRX_OOK (BER < 0.1%, 4.8 kbps, 350 kHz (BER < 0.1%, 40 kbps, 350 kHz BW, OOK, PN15 data) -- -104 -- dBm (BER < 0.1%, 120 kbps, 350 kHz -- -99 -- dBm -- -116 -- dBm -- -108 -- dBm -- -103 -- dBm -- -108 -- dBm -- -102 -- dBm -- -97 -- dBm BW 1.1 -- 850 kHz BW 40 -- 850 kHz -- 0 0.1 Ppm -- 0.5 -- dB BW, OOK, PN15 data) BW, OOK, PN15 data) PRX_2 RX Sensitivity (Si1064/65, Si1084/85) PRX_2 PRX_40 (BER < 0.1%) (2.4 kbps, GFSK, BT = 0.5, f = 30 kHz, 114 kHz Rx BW) (BER < 0.1%) (40 kbps, GFSK, BT = 0.5, f = 20 kHz)Note1 PRX_128 (BER < 0.1%) (128 kbps, GFSK, BT = 0.5, f = 70 kHz, 305 kHz Rx BW) PRX_OOK (BER < 0.1%, 4.8 kbps, 350 kHz BW, OOK, PN15 data) (BER < 0.1%, 40 kbps, 350 kHz BW, OOK, PN15 data) (BER < 0.1%, 120 kbps, 350 kHz BW, OOK, PN15 data) RX Channel Bandwidth (Si1060/61/62/63, Si1080/81/82/83)2 RX Channel Bandwidth (Si1064/65, Si1084/85)2 BER Variation vs Power Level 2 RSSI Resolution1 PRX_RES Up to +5 dBm Input Level RESRSSI Notes: 1. For PER tests, 48 preamble symbols, 4 byte sync word, 10 byte payload and CRC-32 was used. PER and BER tested in the 450-470 MHz band. 2. Guaranteed by design. 70 Rev. 1.0 Si106x/108x Table 4.17. Receiver AC Electrical Characteristics (Continued) Parameter 1-Ch Offset Symbol Test Condition Min Typ Max Unit C/I1-CH Desired Ref Signal 3 dB above sensitivity, BER < 0.1%. Interferer is CW, and desired is modulated with 2.4 kbps F = 1.2 kHz GFSK with BT = 0.5, RX channel BW = 4.8 kHz, channel spacing = 12.5 kHz -- -60 -- dB -- -58 -- dB -- -53 -- dB Desired Ref Signal 3 dB above sensitivity, BER < 0.1%. Interferer is CW, and desired is modulated with 1.2 kbps F = 5.2 kHz GFSK with BT = 0.5, RX channel BW = 58 kHz, channel spacing = 100 kHz -- -56 -- dB -- -59 -- dB Desired Ref Signal 3 dB above sensitivity, BER < 0.1%. Interferer is CW, and desired is modulated with 1.2 kbps F = 5.2 kHz GFSK with BT = 0.5, RX channel BW = 58 kHz, -- -61 -- dB -- -79 -- dB Desired Ref Signal 3 dB above sensitivity, BER = 0.1%. Interferer is CW, and desired is modulated with 2.4 kbps, F = 1.2 kHz GFSK with BT = 0.5, RX channel BW = 4.8 kHz -- -75 -- dB -- -84 -- dB Selectivity, 169 MHz Si1060/61/62/63, Si1080/81/82/83 1-Ch Offset Selectivity, 450 MHz Si1060/61/62/63, Si1080/81/82/83 C/I1-CH 1-Ch Offset Selectivity, C/I1-CH 868/915 MHz Si1060/61/62/63, SI1080/81/82/83 1-Ch Offset Selectivity Si1064/65, Si1084/85 C/I1-CH 2-Ch Offset C/I1-CH Selectivity Blocking 1 MHz Offset Si1064/65, Si1084/85 1MBLOCK Blocking 8 MHz Offset Si1064/65, Si1084/85 8MBLOCK Blocking 1 MHz Offset Si1060/61/62/63, Si1080/81/82/83 1MBLOCK Blocking 8 MHz Offset Si1060/61/62/63, Si1080/81/82/83 8MBLOCK Notes: 1. For PER tests, 48 preamble symbols, 4 byte sync word, 10 byte payload and CRC-32 was used. PER and BER tested in the 450-470 MHz band. 2. Guaranteed by design. Rev. 1.0 71 Si106x/108x Table 4.17. Receiver AC Electrical Characteristics (Continued) Parameter Image Rejection Si1060/61/62/63, Si1080/81/82/83 Image Rejection (Si1064/65, Si1084/85) Spurious (Si1064/65, Si1084/85) Symbol Test Condition Min Typ Max Unit ImREJ No image rejection calibration. Rejection at the image frequency. IF = 468 kHz -- 35 -- dB With image rejection calibration. Rejection at the image frequency. IF = 468 kHz Rejection at the image frequency IF = 468 kHz -- 55 -- dB -- 35 -- dB Measured at RX pins -- -54 -- dBm ImREJ POB_RX1 Notes: 1. For PER tests, 48 preamble symbols, 4 byte sync word, 10 byte payload and CRC-32 was used. PER and BER tested in the 450-470 MHz band. 2. Guaranteed by design. 72 Rev. 1.0 Si106x/108x Table 4.18. Transmitter AC Electrical Characteristics Parameter TX Frequency Range (Si1060/61/62/63, Si1080/81/82/83) Symbol FTX TX Frequency Range Si1064/65, Si1084/85 FTX Test Condition Min 850 Typ -- Max 1050 Unit MHz 420 -- 525 MHz 284 -- 350 MHz 142 -- 175 MHz 850 -- 960 MHz 425 -- 525 MHz 283 -- 350 MHz (G)FSK Data Rate1,2 Si1060/61/62/63, Si1080/81/82/83 DRFSK 0.1 -- 500 kbps 4(G)FSK Data Rate1,2 Si1060/61/62/63, Si1080/81/82/83 DR4FSK 0.2 -- 1000 kbps OOK Data Rate1,2 Si1060/61/62/63, Si1084/85 DROOK 0.1 -- 120 kbps (G)FSK Data Rate1,2 Si1064/65, Si1084/85 DRFSK 1 -- 500 kbps DROOK 0.5 -- 120 kbps OOK Data Rate1,2 Si1064/65, Si1084/85 Modulation Deviation Range Si1060/61/62/63, Si1080/81/82/83 Modulation Deviation Range1 Si1064/65, Si1084/85 Modulation Deviation Resolution Si1060/61/62/63, Si1080/81/82/83 f960 850-1050 MHz -- 1.5 -- MHz f525 420-525 MHz -- 750 -- kHz f350 283-350 MHz -- 500 -- kHz f175 142-175 MHz -- 250 -- kHz f960 850-960 MHz -- 500 kHz f525 425-525 MHz -- 500 kHz f350 283-350 MHz -- 500 kHz FRES-960 850-1050 MHz -- 28.6 -- Hz FRES-525 420-525 MHz -- 14.3 -- Hz FRES-350 283-350 MHz -- 9.5 -- Hz FRES-175 142-175 MHz -- 4.7 -- Hz Notes: 1. Guaranteed by characterization. 2. Output power is dependent on matching components and board layout. Rev. 1.0 73 Si106x/108x Table 4.18. Transmitter AC Electrical Characteristics (Continued) Parameter Modulation Deviation Resolution Si1064/65, Si1084/85 Symbol Test Condition Min Typ Max Unit FRES-960 850-960 MHz -- 114.4 -- Hz FRES-525 425-525 MHz -- 57.2 -- Hz FRES-350 283-350 MHz -- 38.1 -- Hz Output Power Range1, 2 (Si1060/61, Si1080/81) PTX -20 -- +20 dBm Output Power Range1, 2 (Si1062/63/64/65, Si1082/83/84/85) PTX60 -40 -- +13 dBm TX RF Output Steps PRF_OUT Using switched current match within 6 dB of max power -- 0.1 -- dB TX RF Output Level Variation vs. Temperature PRF_TEMP -40 to +85 C -- 1 -- dB PRF_FREQ Measured across 902-928 MHz -- 0.5 -- dB B*T Gaussian Filtering Bandwidth Time Product -- 0.5 -- TX RF Output Level Variation vs. Frequency Transmit Modulation Filtering Notes: 1. Guaranteed by characterization. 2. Output power is dependent on matching components and board layout. 74 Rev. 1.0 Si106x/108x Table 4.19. Auxiliary Block Specifications Parameter XTAL Range * Symbol Min Typ Max Unit 25 -- 32 MHz -- 250 -- s 30MRES -- 70 -- fF tPOR -- -- 5 ms XTALRange 30 MHz XTAL Start-Up Time 30 MHz XTAL Cap Resolution Test Condition t30M POR Reset Time Using XTAL and board layout in reference design. Start-up time will vary with XTAL type and board layout. *Note: XTAL Range tested in production using an external clock source (similar to using a TCXO). Table 4.20. Digital IO Specifications (GPIO_x, nIRQ) Parameter Rise Time1,2 Symbol Test Condition Min Typ Max Unit TRISE 0.1 x VDD to 0.9 x VDD, -- 2.3 -- ns -- 2 -- ns CL = 10 pF, DRV<1:0> = LL Fall Time2,3 TFALL 0.9 x VDD to 0.1 x VDD, CL = 10 pF, DRV<1:0> = LL Input Capacitance CIN -- 2 -- pF Logic High Level Input Voltage VIH VDD x 0.7 -- -- V Logic Low Level Input Voltage VIL -- -- VDD x 0.3 V Input Current IIN 0<VIN< VDD -10 -- 10 A Input Current If Pullup is Activated IINP VIL = 0 V 1 -- 10 A Drive Strength for Output IOmaxLL DRV[1:0] = LL -- 6.66 -- mA IOmaxLH DRV[1:0] = LH -- 5.03 -- mA IOmaxHL DRV[1:0] = HL -- 3.16 -- mA IOmaxHH DRV[1:0] = HH -- 1.13 -- mA Low Level2 Notes: 1. 8 ns is typical for GPIO0 rise time. 2. Assuming VDD = 3.3 V, drive strength is specified at Voh (min) = 2.64 V and Vol(max) = 0.66 V at room temperature. 3. 2.4 ns is typical for GPIO0 fall time. Rev. 1.0 75 Si106x/108x Table 4.20. Digital IO Specifications (GPIO_x, nIRQ) (Continued) Parameter Test Condition Min Typ Max Unit IOmaxLL DRV[1:0] = LL -- 5.75 -- mA IOmaxLH DRV[1:0] = LH -- 4.37 -- mA IOmaxHL DRV[1:0] = HL -- 2.73 -- mA IOmaxHH DRV[1:0] = HH -- 0.96 -- mA IOmaxLL DRV[1:0] = LL -- 2.53 -- mA IOmaxLH DRV[1:0] = LH -- 2.21 -- mA IOmaxHL DRV[1:0] = HL -- 1.7 -- mA IOmaxHH DRV[1:0] = HH -- 0.80 -- mA Logic High Level Output Voltage VOH DRV[1:0] = HL VDD x 0.8 -- -- V Logic Low Level Output Voltage VOL DRV[1:0] = HL -- -- VDD x 0.2 V Drive Strength for Output High Level2 Drive Strength for Output High Level for GPIO02 Symbol Notes: 1. 8 ns is typical for GPIO0 rise time. 2. Assuming VDD = 3.3 V, drive strength is specified at Voh (min) = 2.64 V and Vol(max) = 0.66 V at room temperature. 3. 2.4 ns is typical for GPIO0 fall time. 76 Rev. 1.0 Si106x/108x Table 4.21. Absolute Maximum Ratings (Radio) Parameter Value Unit VDD to GND -0.3, +3.6 V Instantaneous VRF-peak to GND on TX Output Pin -0.3, +8.0 V Sustained VRF-peak to GND on TX Output Pin -0.3, +6.5 V Voltage on Digital Control Inputs -0.3, VDD + 0.3 V Voltage on Analog Inputs -0.3, VDD + 0.3 V +10 dBm RX Input Power Note: Stresses beyond those listed under "Absolute Maximum Ratings" may cause permanent damage to the device. These are stress ratings only and functional operation of the device at or beyond these ratings in the operational sections of the specifications is not implied. Exposure to absolute maximum rating conditions for extended periods may affect device reliability. Power Amplifier may be damaged if switched on without proper load or termination connected. TX matching network design will influence TX VRF-peak on TX output pin. Caution: ESD sensitive device. Table 4.22. Thermal Properties Parameter Value Unit -40 to +85 C 30 C/W Maximum Junction Temperature TJ +125 C Storage Temperature Range TSTG -55 to +125 C Operating Ambient Temperature Range TA Thermal Impedance JA Note: Stresses beyond those listed under "Absolute Maximum Ratings" may cause permanent damage to the device. Rev. 1.0 77 Si106x/108x 5. 10-Bit SAR ADC with 16-bit Auto-Averaging Accumulator and Autonomous Low Power Burst Mode The ADC0 on the Si106x/108x is a 300 ksps, 10-bit successive-approximation-register (SAR) ADC with integrated track-and-hold and programmable window detector. ADC0 also has an autonomous low power Burst Mode which can automatically enable ADC0, capture and accumulate samples, then place ADC0 in a low power shutdown mode without CPU intervention. It also has a 16-bit accumulator that can automatically oversample and average the ADC results. The ADC is fully configurable under software control via Special Function Registers. The ADC0 operates in Single-ended mode and may be configured to measure various different signals using the analog multiplexer described in "5.5. ADC0 Analog Multiplexer" on page 95. The voltage reference for the ADC is selected as described in "5.7. Voltage and Ground Reference Options" on page 100. VDD From AMUX0 Burst Mode Logic 10-bit SAR AIN+ ADC AD0CM1 AD0CM2 AD0CM0 AD0BUSY (W ) 001 Timer 0 Overflow 010 Timer 2 Overflow 011 Timer 3 Overflow 100 CNVSTR Input REF 16-Bit Accumulator SYSCLK AD0TM AMP0GN AD08BE AD0SC0 AD0SC1 AD0SC2 AD0SC3 AD0SC4 ADC0CF 000 ADC0L ADC0PWR Start Conversion ADC0LTH ADC0H ADC0TK AD0WINT AD0INT AD0BUSY AD0EN BURSTEN ADC0CN AD0WINT ADC0LTL 32 W indow Compare Logic ADC0GTH ADC0GTL Figure 5.1. ADC0 Functional Block Diagram 5.1. Output Code Formatting The registers ADC0H and ADC0L contain the high and low bytes of the output conversion code from the ADC at the completion of each conversion. Data can be right-justified or left-justified, depending on the setting of the AD0SJST[2:0]. When the repeat count is set to 1, conversion codes are represented as 10bit unsigned integers. Inputs are measured from 0 to VREF x 1023/1024. Example codes are shown below for both right-justified and left-justified data. Unused bits in the ADC0H and ADC0L registers are set to 0. Rev. 1.0 78 Si106x/108x Input Voltage Right-Justified ADC0H:ADC0L (AD0SJST = 000) Left-Justified ADC0H:ADC0L (AD0SJST = 100) VREF x 1023/1024 VREF x 512/1024 VREF x 256/1024 0 0x03FF 0x0200 0x0100 0x0000 0xFFC0 0x8000 0x4000 0x0000 When the repeat count is greater than 1, the output conversion code represents the accumulated result of the conversions performed and is updated after the last conversion in the series is finished. Sets of 4, 8, 16, 32, or 64 consecutive samples can be accumulated and represented in unsigned integer format. The repeat count can be selected using the AD0RPT bits in the ADC0AC register. When a repeat count higher than 1, the ADC output must be right-justified (AD0SJST = 0xx); unused bits in the ADC0H and ADC0L registers are set to 0. The example below shows the right-justified result for various input voltages and repeat counts. Notice that accumulating 2n samples is equivalent to left-shifting by n bit positions when all samples returned from the ADC have the same value. Input Voltage Repeat Count = 4 Repeat Count = 16 Repeat Count = 64 VREF x 1023/1024 VREF x 512/1024 VREF x 511/1024 0 0x0FFC 0x0800 0x07FC 0x0000 0x3FF0 0x2000 0x1FF0 0x0000 0xFFC0 0x8000 0x7FC0 0x0000 The AD0SJST bits can be used to format the contents of the 16-bit accumulator. The accumulated result can be shifted right by 1, 2, or 3 bit positions. Based on the principles of oversampling and averaging, the effective ADC resolution increases by 1 bit each time the oversampling rate is increased by a factor of 4. The example below shows how to increase the effective ADC resolution by 1, 2, and 3 bits to obtain an effective ADC resolution of 11-bit, 12-bit, or 13-bit respectively without CPU intervention. Input Voltage Repeat Count = 4 Shift Right = 1 11-Bit Result Repeat Count = 16 Shift Right = 2 12-Bit Result Repeat Count = 64 Shift Right = 3 13-Bit Result VREF x 1023/1024 VREF x 512/1024 VREF x 511/1024 0 0x07F7 0x0400 0x03FE 0x0000 0x0FFC 0x0800 0x04FC 0x0000 0x1FF8 0x1000 0x0FF8 0x0000 79 Rev. 1.0 Si106x/108x 5.2. Modes of Operation ADC0 has a maximum conversion speed of 300 ksps. The ADC0 conversion clock (SARCLK) is a divided version of the system clock when Burst Mode is disabled (BURSTEN = 0), or a divided version of the low power oscillator when Burst Mode is enabled (BURSEN = 1). The clock divide value is determined by the AD0SC bits in the ADC0CF register. 5.2.1. Starting a Conversion A conversion can be initiated in one of five ways, depending on the programmed states of the ADC0 Start of Conversion Mode bits (AD0CM2-0) in register ADC0CN. Conversions may be initiated by one of the following: 1. Writing a 1 to the AD0BUSY bit of register ADC0CN 2. A Timer 0 overflow (i.e., timed continuous conversions) 3. A Timer 2 overflow 4. A Timer 3 overflow 5. A rising edge on the CNVSTR input signal (pin P0.6) Writing a 1 to AD0BUSY provides software control of ADC0 whereby conversions are performed "ondemand". During conversion, the AD0BUSY bit is set to logic 1 and reset to logic 0 when the conversion is complete. The falling edge of AD0BUSY triggers an interrupt (when enabled) and sets the ADC0 interrupt flag (AD0INT). Note: When polling for ADC conversion completions, the ADC0 interrupt flag (AD0INT) should be used. Converted data is available in the ADC0 data registers, ADC0H:ADC0L, when bit AD0INT is logic 1. Note that when Timer 2 or Timer 3 overflows are used as the conversion source, Low Byte overflows are used if Timer 2/3 is in 8-bit mode; High byte overflows are used if Timer 2/3 is in 16-bit mode. See "31. Timers" on page 311 for timer configuration. Important Note About Using CNVSTR: The CNVSTR input pin also functions as Port pin P0.6. When the CNVSTR input is used as the ADC0 conversion source, Port pin P0.6 should be skipped by the Digital Crossbar. To configure the Crossbar to skip P0.6, set to 1 Bit 6 in register P0SKIP. See "20. Si106x/108xPort Input/Output" on page 217 for details on Port I/O configuration. Important Note: When operating the device in one-cell mode, there is an option available to automatically synchronize the start of conversion with the quietest portion of the dc-dc converter switching cycle. Activating this option may help to reduce interference from internal or external power supply noise generated by the dc-dc converter. Asserting this bit will hold off the start of an ADC conversion initiated by any of the methods described above until the ADC receives a synchronizing signal from the dc-dc converter. The delay in initiation of the conversion can be as much as one cycle of the dc-dc converter clock, which is 625 ns at the minimum dc-dc clock frequency of 1.6 MHz. The synchronization feature also causes the dcdc converter clock to be used as the ADC0 conversion clock. The maximum conversion rate will be limited to approximately 170 ksps at the maximum dc-dc converter clock rate of 3.2 MHz. In this mode, the ADC0 SAR Conversion Clock Divider must be set to 1 by setting AD0SC[4:0] = 00000b in SFR register ADC0CF. To provide additional flexibility in minimizing noise, the ADC0 conversion clock provided by the dc-dc converter can be inverted by setting the AD0CKINV bit in the DC0CF register. For additional information on the synchronization feature, see the description of the SYNC bit in "SFR Definition 15.1. DC0CN: DC-DC Converter Control" on page 181 and the description of the AD0CKINV bit in "SFR Definition 15.2. DC0CF: DC-DC Converter Configuration" on page 182. This bit must be set to 0 in two-cell mode for the ADC to operate. Rev. 1.0 80 Si106x/108x 5.2.2. Tracking Modes Each ADC0 conversion must be preceded by a minimum tracking time in order for the converted result to be accurate. The minimum tracking time is given in Table 4.9. The AD0TM bit in register ADC0CN controls the ADC0 track-and-hold mode. In its default state when Burst Mode is disabled, the ADC0 input is continuously tracked, except when a conversion is in progress. When the AD0TM bit is logic 1, ADC0 operates in low-power track-and-hold mode. In this mode, each conversion is preceded by a tracking period of 3 SAR clocks (after the start-of-conversion signal). When the CNVSTR signal is used to initiate conversions in low-power tracking mode, ADC0 tracks only when CNVSTR is low; conversion begins on the rising edge of CNVSTR (see Figure 5.2). Tracking can also be disabled (shutdown) when the device is in low power standby or sleep modes. Low-power track-and-hold mode is also useful when AMUX settings are frequently changed, due to the settling time requirements described in "5.2.4. Settling Time Requirements" on page 84. A. ADC0 Timing for External Trigger Source CNVSTR (AD0CM[2:0]=100) 1 2 3 4 5 6 7 8 9 10 11 12 13 14 SAR Clocks AD0TM=1 AD0TM=0 Write '1' to AD0BUSY, Timer 0, Timer 2, Timer 1, Timer 3 Overflow (AD0CM[2:0]=000, 001,010 011, 101) Low Power or Convert Track or Convert Low Power Mode Convert Track 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 Low Power Track or Convert Convert Low Power Mode 1 2 3 4 5 6 7 8 9 10 11 12 13 14 SAR Clocks AD0TM=0 Convert B. ADC0 Timing for Internal Trigger Source SAR Clocks AD0TM=1 Track Track or Convert Convert Track Figure 5.2. 10-Bit ADC Track and Conversion Example Timing (BURSTEN = 0) 81 Rev. 1.0 Si106x/108x 5.2.3. Burst Mode Burst Mode is a power saving feature that allows ADC0 to remain in a low power state between conversions. When Burst Mode is enabled, ADC0 wakes from a low power state, accumulates 1, 4, 8, 16, 32, or 64 using an internal Burst Mode clock (approximately 20 MHz), then re-enters a low power state. Since the Burst Mode clock is independent of the system clock, ADC0 can perform multiple conversions then enter a low power state within a single system clock cycle, even if the system clock is slow (e.g. 32.768 kHz), or suspended. Burst Mode is enabled by setting BURSTEN to logic 1. When in Burst Mode, AD0EN controls the ADC0 idle power state (i.e., the state ADC0 enters when not tracking or performing conversions). If AD0EN is set to logic 0, ADC0 is powered down after each burst. If AD0EN is set to logic 1, ADC0 remains enabled after each burst. On each convert start signal, ADC0 is awakened from its Idle Power State. If ADC0 is powered down, it will automatically power up and wait the programmable Power-Up Time controlled by the AD0PWR bits. Otherwise, ADC0 will start tracking and converting immediately. Figure 5.3 shows an example of Burst Mode Operation with a slow system clock and a repeat count of 4. When Burst Mode is enabled, a single convert start will initiate a number of conversions equal to the repeat count. When Burst Mode is disabled, a convert start is required to initiate each conversion. In both modes, the ADC0 End of Conversion Interrupt Flag (AD0INT) will be set after "repeat count" conversions have been accumulated. Similarly, the Window Comparator will not compare the result to the greater-than and less-than registers until "repeat count" conversions have been accumulated. In Burst Mode, tracking is determined by the settings in AD0PWR and AD0TK. The default settings for these registers will work in most applications without modification; however, settling time requirements may need adjustment in some applications. Refer to "5.2.4. Settling Time Requirements" on page 84 for more details. Notes: Setting AD0TM to 1 will insert an additional 3 SAR clocks of tracking before each conversion, regardless of the settings of AD0PWR and AD0TK. When using Burst Mode, care must be taken to issue a convert start signal no faster than once every four SYSCLK periods. This includes external convert start signals. A rising edge of external start-of-conversion (CNVSTR) will cause only one ADC conversion in Burst Mode, regardless of the value of the Repeat Count field. The end-of-conversion interrupt will occur after the number of conversions specified in Repeat Count have completed. In other words, if Repeat Count is set to 4, four pulses on CNVSTR will cause an ADC end-of-conversion interrupt. Refer to the bottom portion of Figure 5.3, "Burst Mode Tracking Example with Repeat Count Set to 4," on page 83 for an example. To start multiple conversions in Burst Mode with one external start-of-conversion signal, the external interrupts (/INT0 or /INT1) or Port Match can be used to trigger an ISR that writes to AD0BUSY. External interrupts are configurable to be active low or active high, edge or level sensitive, but is only avail-able on a limited number of pins. Port Match is only level sensitive, but is available on more port pins than the external interrupts. Refer to section "11.6. External Interrupts INT0 and INT1" on page 147 for details on external interrupts and section "20.4. Port Match" on page 226 for details on Port Match. Rev. 1.0 82 Si106x/108x System Clock Convert Start (AD0BUSY or Timer Overflow) Post-Tracking AD0TM = 01 AD0EN = 0 Powered Down Power-Up and Idle T C T C T C T C Powered Down Power-Up and Idle T C.. Dual-Tracking AD0TM = 11 AD0EN = 0 Powered Down Power-Up and Track T C T C T C T C Powered Down Power-Up and Track T C.. AD0PWR Post-Tracking AD0TM = 01 AD0EN = 1 Idle T C T C T C T C Idle T C T C T C.. Dual-Tracking AD0TM = 11 AD0EN = 1 Track T C T C T C T C Track T C T C T C.. T = Tracking C = Converting Convert Start (CNVSTR) Post-Tracking AD0TM = 01 AD0EN = 0 Powered Down Power-Up and Idle T C Powered Down Power-Up and Idle T C.. Dual-Tracking AD0TM = 11 AD0EN = 0 Powered Down Power-Up and Track T C Powered Down Power-Up and Track T C.. AD0PWR Post-Tracking AD0TM = 01 AD0EN = 1 Idle T C Idle T C Idle.. Dual-Tracking AD0TM = 11 AD0EN = 1 Track T C Track T C Track.. T = Tracking C = Converting Figure 5.3. Burst Mode Tracking Example with Repeat Count Set to 4 83 Rev. 1.0 Si106x/108x 5.2.4. Settling Time Requirements A minimum amount of tracking time is required before each conversion can be performed, to allow the sampling capacitor voltage to settle. This tracking time is determined by the AMUX0 resistance, the ADC0 sampling capacitance, any external source resistance, and the accuracy required for the conversion. Note that in low-power tracking mode, three SAR clocks are used for tracking at the start of every conversion. For many applications, these three SAR clocks will meet the minimum tracking time requirements, and higher values for the external source impedance will increase the required tracking time. Figure 5.4 shows the equivalent ADC0 input circuit. The required ADC0 settling time for a given settling accuracy (SA) may be approximated by Equation 5.1. When measuring the Temperature Sensor output or VDD with respect to GND, RTOTAL reduces to RMUX. See Table 4.9 for ADC0 minimum settling time requirements as well as the mux impedance and sampling capacitor values. n 2 t = ln ------- R TOTAL C SAMPLE SA Equation 5.1. ADC0 Settling Time Requirements Where: SA is the settling accuracy, given as a fraction of an LSB (for example, 0.25 to settle within 1/4 LSB) t is the required settling time in seconds RTOTAL is the sum of the AMUX0 resistance and any external source resistance. n is the ADC resolution in bits (10). MUX Select P0.x R MUX C SAMPLE RCInput= R MUX * C SAMPLE Note: The value of CSAMPLE depends on the PGA Gain. See Table 4.9 for details. Figure 5.4. ADC0 Equivalent Input Circuits Rev. 1.0 84 Si106x/108x 5.2.5. Gain Setting The ADC has gain settings of 1x and 0.5x. In 1x mode, the full scale reading of the ADC is determined directly by VREF. In 0.5x mode, the full-scale reading of the ADC occurs when the input voltage is VREF x 2. The 0.5x gain setting can be useful to obtain a higher input Voltage range when using a small VREF voltage, or to measure input voltages that are between VREF and VDD. Gain settings for the ADC are controlled by the AMP0GN bit in register ADC0CF. 5.3. 8-Bit Mode Setting the ADC08BE bit in register ADC0CF to 1 will put the ADC in 8-bit mode.In 8-bit mode, only the 8 MSBs of data are converted, allowing the conversion to be completed in two fewer SAR clock cycles than a 10-bit conversion. This can result in an overall lower power consumption since the system can spend more time in a low power mode. The two LSBs of a conversion are always 00 in this mode, and the ADC0L register will always read back 0x00. 85 Rev. 1.0 Si106x/108x SFR Definition 5.1. ADC0CN: ADC0 Control Bit 7 6 5 4 Name AD0EN BURSTEN AD0INT Type R/W R/W R/W W R/W Reset 0 0 0 0 0 AD0EN 2 AD0BUSY AD0WINT SFR Page = 0x0; SFR Address = 0xE8; bit-addressable; Bit Name 7 3 1 0 ADC0CM R/W 0 0 0 Function ADC0 Enable. 0: ADC0 Disabled (low-power shutdown). 1: ADC0 Enabled (active and ready for data conversions). 6 BURSTEN ADC0 Burst Mode Enable. 0: ADC0 Burst Mode Disabled. 1: ADC0 Burst Mode Enabled. 5 AD0INT ADC0 Conversion Complete Interrupt Flag. Set by hardware upon completion of a data conversion (BURSTEN=0), or a burst of conversions (BURSTEN=1). Can trigger an interrupt. Must be cleared by software. 4 AD0BUSY ADC0 Busy. Writing 1 to this bit initiates an ADC conversion when ADC0CM[2:0] = 000. 3 AD0WINT ADC0 Window Compare Interrupt Flag. Set by hardware when the contents of ADC0H:ADC0L fall within the window specified by ADC0GTH:ADC0GTL and ADC0LTH:ADC0LTL. Can trigger an interrupt. Must be cleared by software. 2:0 ADC0CM[2:0] ADC0 Start of Conversion Mode Select. Specifies the ADC0 start of conversion source. 000: ADC0 conversion initiated on write of 1 to AD0BUSY. 001: ADC0 conversion initiated on overflow of Timer 0. 010: ADC0 conversion initiated on overflow of Timer 2. 011: ADC0 conversion initiated on overflow of Timer 3. 1xx: ADC0 conversion initiated on rising edge of CNVSTR. Rev. 1.0 86 Si106x/108x SFR Definition 5.2. ADC0CF: ADC0 Configuration Bit 7 6 5 4 3 2 1 0 Name AD0SC[4:0] AD08BE AD0TM AMP0GN Type R/W R/W R/W R/W 0 0 0 Reset 1 1 1 1 SFR Page = 0x0; SFR Address = 0xBC Bit Name 7:3 1 Function AD0SC[4:0] ADC0 SAR Conversion Clock Divider. SAR Conversion clock is derived from FCLK by the following equation, where AD0SC refers to the 5-bit value held in bits AD0SC[4:0]. SAR Conversion clock requirements are given in Table 4.9. BURSTEN = 0: FCLK is the current system clock. BURSTEN = 1: FCLK is the 20 MHz low power oscillator, independent of the system clock. FCLK AD0SC = -------------------- - 1 * CLK SAR *Round the result up. or FCLK CLK SAR = ---------------------------AD0SC + 1 2 AD08BE ADC0 8-Bit Mode Enable. 0: ADC0 operates in 10-bit mode (normal operation). 1: ADC0 operates in 8-bit mode. 1 AD0TM ADC0 Track Mode. Selects between Normal or Delayed Tracking Modes. 0: Normal Track Mode: When ADC0 is enabled, conversion begins immediately following the start-of-conversion signal. 1: Delayed Track Mode: When ADC0 is enabled, conversion begins 3 SAR clock cycles following the start-of-conversion signal. The ADC is allowed to track during this time. 0 87 AMP0GN ADC0 Gain Control. 0: The on-chip PGA gain is 0.5. 1: The on-chip PGA gain is 1. Rev. 1.0 Si106x/108x SFR Definition 5.3. ADC0AC: ADC0 Accumulator Configuration Bit 7 6 5 4 Name Reserved AD0AE AD0SJST AD0RPT Type R/W W R/W R/W Reset 0 0 0 0 SFR Page = 0x0; SFR Address = 0xBA Bit Name 7 6 Reserved AD0AE 3 0 2 0 1 0 0 0 Function Read = 0b. ADC0 Accumulate Enable. Enables multiple conversions to be accumulated when burst mode is disabled. 0: ADC0H:ADC0L contain the result of the latest conversion when Burst Mode is disabled. 1: ADC0H:ADC0L contain the accumulated conversion results when Burst Mode is disabled. Software must write 0x0000 to ADC0H:ADC0L to clear the accumulated result. This bit is write-only. Always reads 0b. 5:3 AD0SJST[2:0] ADC0 Accumulator Shift and Justify. Specifies the format of data read from ADC0H:ADC0L. 000: Right justified. No shifting applied. 001: Right justified. Shifted right by 1 bit. 010: Right justified. Shifted right by 2 bits. 011: Right justified. Shifted right by 3 bits. 100: Left justified. No shifting applied. All remaining bit combinations are reserved. 2:0 AD0RPT[2:0] ADC0 Repeat Count. Selects the number of conversions to perform and accumulate in Burst Mode. This bit field must be set to 000 if Burst Mode is disabled. 000: Perform and Accumulate 1 conversion. 001: Perform and Accumulate 4 conversions. 010: Perform and Accumulate 8 conversions. 011: Perform and Accumulate 16 conversions. 100: Perform and Accumulate 32 conversions. 101: Perform and Accumulate 64 conversions. All remaining bit combinations are reserved. Rev. 1.0 88 Si106x/108x SFR Definition 5.4. ADC0PWR: ADC0 Burst Mode Power-Up Time Bit 7 6 5 4 Name Reserved Type R R R R Reset 0 0 0 0 2 1 0 AD0PWR[3:0] SFR Page = 0xF; SFR Address = 0xBA Bit Name 7 6:4 3:0 3 R/W 1 1 1 1 Function Reserved Read = 0b; Must write 0b. Unused Read = 0000b; Write = Don't Care. AD0PWR[3:0] ADC0 Burst Mode Power-Up Time. Sets the time delay required for ADC0 to power up from a low power state. For BURSTEN = 0: ADC0 power state controlled by AD0EN. For BURSTEN = 1 and AD0EN = 1: ADC0 remains enabled and does not enter a low power state after all conversions are complete. Conversions can begin immediately following the start-of-conversion signal. For BURSTEN = 1 and AD0EN = 0: ADC0 enters a low power state (as specified in Table 5.1) after all conversions are complete. Conversions can begin a programmed delay after the start-of-conversion signal. The ADC0 Burst Mode Power-Up time is programmed according to the following equation: Tstartup AD0PWR = ---------------------- - 1 400ns or Tstartup = AD0PWR + 1 400ns 89 Rev. 1.0 Si106x/108x SFR Definition 5.5. ADC0TK: ADC0 Burst Mode Track Time Bit 7 6 5 4 2 1 0 1 0 AD0TK[5:0] Name Type R R Reset 0 0 R/W 0 1 SFR Page = 0xF; SFR Address = 0xBD Bit Name 7:6 5:0 3 0 1 Function Unused Read = 00b; Write = Don't Care. AD0TK[5:0] ADC0 Burst Mode Track Time. Sets the time delay between consecutive conversions performed in Burst Mode. The ADC0 Burst Mode Track time is programmed according to the following equation: Ttrack AD0TK = 63 - ----------------- - 1 50ns or Ttrack = 64 - AD0TK 50ns Notes: 1. If AD0TM is set to 1, an additional 3 SAR clock cycles of Track time will be inserted prior to starting the conversion. 2. The Burst Mode Track delay is not inserted prior to the first conversion. The required tracking time for the first conversion should be met by the Burst Mode Power-Up Time. Rev. 1.0 90 Si106x/108x SFR Definition 5.6. ADC0H: ADC0 Data Word High Byte Bit 7 6 5 4 3 Name ADC0[15:8] Type R/W Reset 0 0 0 0 0 SFR Page = 0x0; SFR Address = 0xBE Bit Name Description 7:0 ADC0[15:8] ADC0 Data Word High Byte. 2 1 0 0 0 0 Read Write Most Significant Byte of the 16-bit ADC0 Accumulator formatted according to the settings in AD0SJST[2:0]. Set the most significant byte of the 16-bit ADC0 Accumulator to the value written. Note: If Accumulator shifting is enabled, the most significant bits of the value read will be zeros. This register should not be written when the SYNC bit is set to 1. SFR Definition 5.7. ADC0L: ADC0 Data Word Low Byte Bit 7 6 5 4 Name ADC0[7:0] Type R/W Reset 0 0 0 0 SFR Page = 0x0; SFR Address = 0xBD; Bit Name Description 7:0 ADC0[7:0] ADC0 Data Word Low Byte. 3 2 1 0 0 0 0 0 Read Write Least Significant Byte of the 16-bit ADC0 Accumulator formatted according to the settings in AD0SJST[2:0]. Set the least significant byte of the 16-bit ADC0 Accumulator to the value written. Note: If Accumulator shifting is enabled, the most significant bits of the value read will be the least significant bits of the accumulator high byte. This register should not be written when the SYNC bit is set to 1. 91 Rev. 1.0 Si106x/108x 5.4. Programmable Window Detector The ADC Programmable Window Detector continuously compares the ADC0 output registers to user-programmed limits, and notifies the system when a desired condition is detected. This is especially effective in an interrupt-driven system, saving code space and CPU bandwidth while delivering faster system response times. The window detector interrupt flag (AD0WINT in register ADC0CN) can also be used in polled mode. The ADC0 Greater-Than (ADC0GTH, ADC0GTL) and Less-Than (ADC0LTH, ADC0LTL) registers hold the comparison values. The window detector flag can be programmed to indicate when measured data is inside or outside of the user-programmed limits, depending on the contents of the ADC0 Less-Than and ADC0 Greater-Than registers. SFR Definition 5.8. ADC0GTH: ADC0 Greater-Than High Byte Bit 7 6 5 4 3 Name AD0GT[15:8] Type R/W Reset 1 1 1 1 1 SFR Page = 0x0; SFR Address = 0xC4 Bit Name 7:0 2 1 0 1 1 1 Function AD0GT[15:8] ADC0 Greater-Than High Byte. Most Significant Byte of the 16-bit Greater-Than window compare register. SFR Definition 5.9. ADC0GTL: ADC0 Greater-Than Low Byte Bit 7 6 5 4 3 Name AD0GT[7:0] Type R/W Reset 1 1 1 1 SFR Page = 0x0; SFR Address = 0xC3 Bit Name 7:0 1 2 1 0 1 1 1 Function AD0GT[7:0] ADC0 Greater-Than Low Byte. Least Significant Byte of the 16-bit Greater-Than window compare register. Note: In 8-bit mode, this register should be set to 0x00. Rev. 1.0 92 Si106x/108x SFR Definition 5.10. ADC0LTH: ADC0 Less-Than High Byte Bit 7 6 5 4 3 Name AD0LT[15:8] Type R/W Reset 0 0 0 0 0 SFR Page = 0x0; SFR Address = 0xC6 Bit Name 7:0 2 1 0 0 0 0 Function AD0LT[15:8] ADC0 Less-Than High Byte. Most Significant Byte of the 16-bit Less-Than window compare register. SFR Definition 5.11. ADC0LTL: ADC0 Less-Than Low Byte Bit 7 6 5 4 3 Name AD0LT[7:0] Type R/W Reset 0 0 0 0 SFR Page = 0x0; SFR Address = 0xC5 Bit Name 7:0 0 2 1 0 0 0 0 Function AD0LT[7:0] ADC0 Less-Than Low Byte. Least Significant Byte of the 16-bit Less-Than window compare register. Note: In 8-bit mode, this register should be set to 0x00. 5.4.1. Window Detector In Single-Ended Mode Figure 5.5 shows two example window comparisons for right-justified data, with ADC0LTH:ADC0LTL = 0x0080 (128d) and ADC0GTH:ADC0GTL = 0x0040 (64d). The input voltage can range from 0 to VREF x (1023/1024) with respect to GND, and is represented by a 10-bit unsigned integer value. In the left example, an AD0WINT interrupt will be generated if the ADC0 conversion word (ADC0H:ADC0L) is within the range defined by ADC0GTH:ADC0GTL and ADC0LTH:ADC0LTL (if 0x0040 < ADC0H:ADC0L < 0x0080). In the right example, and AD0WINT interrupt will be generated if the ADC0 conversion word is outside of the range defined by the ADC0GT and ADC0LT registers (if ADC0H:ADC0L < 0x0040 or ADC0H:ADC0L > 0x0080). Figure 5.6 shows an example using left-justified data with the same comparison values. 93 Rev. 1.0 Si106x/108x ADC0H:ADC0L ADC0H:ADC0L Input Voltage (Px.x - GND) VREF x (1023/1024) Input Voltage (Px.x - GND) 0x03FF VREF x (1023/1024) 0x03FF AD0WINT not affected AD0WINT=1 0x0081 VREF x (128/1024) 0x0080 0x0081 ADC0LTH:ADC0LTL VREF x (128/1024) 0x007F 0x0080 0x007F AD0WINT=1 VREF x (64/1024) 0x0041 0x0040 ADC0GTH:ADC0GTL VREF x (64/1024) 0x003F 0x0041 0x0040 ADC0GTH:ADC0GTL AD0WINT not affected ADC0LTH:ADC0LTL 0x003F AD0WINT=1 AD0WINT not affected 0 0x0000 0 0x0000 Figure 5.5. ADC Window Compare Example: Right-Justified Single-Ended Data ADC0H:ADC0L ADC0H:ADC0L Input Voltage (Px.x - GND) VREF x (1023/1024) Input Voltage (Px.x - GND) 0xFFC0 VREF x (1023/1024) 0xFFC0 AD0WINT not affected AD0WINT=1 0x2040 VREF x (128/1024) 0x2000 0x2040 ADC0LTH:ADC0LTL VREF x (128/1024) 0x1FC0 0x2000 0x1FC0 AD0WINT=1 0x1040 VREF x (64/1024) 0x1000 0x1040 ADC0GTH:ADC0GTL VREF x (64/1024) 0x0FC0 0x1000 ADC0GTH:ADC0GTL AD0WINT not affected ADC0LTH:ADC0LTL 0x0FC0 AD0WINT=1 AD0WINT not affected 0 0x0000 0 0x0000 Figure 5.6. ADC Window Compare Example: Left-Justified Single-Ended Data 5.4.2. ADC0 Specifications See "4. Electrical Characteristics" on page 42 for a detailed listing of ADC0 specifications. Rev. 1.0 94 Si106x/108x 5.5. ADC0 Analog Multiplexer ADC0 on Si106x/108x has an analog multiplexer, referred to as AMUX0. AMUX0 selects the positive inputs to the single-ended ADC0. Any of the following may be selected as the positive input: Port I/O pins, the on-chip temperature sensor, Regulated Digital Supply Voltage (Output of VREG0), VDD_MCU Supply, or the positive input may be connected to GND. The ADC0 input channels are selected in the ADC0MX register described in SFR Definition 5.12. AD0MX4 AD0MX3 AD0MX2 AD0MX1 AM0MX0 ADC0MX P0.0 Programmable Attenuator AIN+ P2.6* AMUX Temp Sensor ADC0 Gain = 0. 5 or 1 Digital Supply VDD_MCU Figure 5.7. ADC0 Multiplexer Block Diagram Important Note About ADC0 Input Configuration: Port pins selected as ADC0 inputs should be configured as analog inputs, and should be skipped by the Digital Crossbar. To configure a Port pin for analog input, set to 0 the corresponding bit in register PnMDIN and disable the digital driver (PnMDOUT = 0 and Port Latch = 1). To force the Crossbar to skip a Port pin, set to 1 the corresponding bit in register PnSKIP. See Section "20. Si106x/108xPort Input/Output" on page 217 for more Port I/O configuration details. Rev. 1.0 95 Si106x/108x SFR Definition 5.12. ADC0MX: ADC0 Input Channel Select Bit 7 6 5 4 3 2 1 0 AD0MX Name Type R R R R/W R/W R/W R/W R/W Reset 0 0 0 1 1 1 1 1 SFR Page = 0x0; SFR Address = 0xBB Bit Name 7:5 4:0 Unused AD0MX Function Read = 000b; Write = Don't Care. AMUX0 Positive Input Selection. Selects the positive input channel for ADC0. 00000: 00001: 00010: 00011: 00100: 00101: 00110: 00111: 01000: 01001: 01010: 01011: 01100: 01101: 01110: 01111: P0.0 P0.1 P0.2 P0.3 P0.4 P0.5 P0.6 P0.7 Reserved. Reserved. Reserved. Reserved. Reserved. P1.5 P1.6 P1.7 10000: 10001: 10010: 10011: 10100: 10101: 10110: 10111: 11000: 11001: 11010: 11011: 11100: P2.0 P2.1 P2.2 P2.3 P2.4 P2.5 P2.6 Reserved. Reserved. Reserved. Reserved. Temperature Sensor* VDD_MCU Supply Voltage (1.8-3.6 V) 11101: Digital Supply Voltage (VREG0 Output, 1.7 V Typical) 11110: VDD_MCU Supply Voltage (1.8-3.6 V) Ground 11111: *Note: Before switching the ADC multiplexer from another channel to the temperature sensor, the ADC mux should select the "Ground" channel as an intermediate step. The intermediate "Ground" channel selection step will discharge any voltage on the ADC sampling capacitor from the previous channel selection. This will prevent the possibility of a high voltage (> 2 V) being presented to the temperature sensor circuit, which can otherwise impact its long-term reliability. 96 Rev. 1.0 Si106x/108x 5.6. Temperature Sensor An on-chip temperature sensor is included on the Si106x/108x which can be directly accessed via the ADC multiplexer in single-ended configuration. To use the ADC to measure the temperature sensor, the ADC mux channel should select the temperature sensor. The temperature sensor transfer function is shown in Figure 5.8. The output voltage (VTEMP) is the positive ADC input when the ADC multiplexer is set correctly. The TEMPE bit in register REF0CN enables/disables the temperature sensor, as described in SFR Definition 5.15. While disabled, the temperature sensor defaults to a high impedance state and any ADC measurements performed on the sensor will result in meaningless data. Refer to Table 4.9 for the slope and offset parameters of the temperature sensor. Note: Before switching the ADC multiplexer from another channel to the temperature sensor, the ADC mux should select the "Ground" channel as an intermediate step. The intermediate "Ground" channel selection step will discharge any voltage on the ADC sampling capacitor from the previous channel selection. This will prevent the possibility of a high voltage (> 2 V) being presented to the temperature sensor circuit, which can otherwise impact its long-term reliability. V TEMP = Slope x (Temp C - 25) + Offset TempC = 25 + (V TEMP - Offset) / Slope Voltage Slope ( V / deg C) Offset ( V at 25 Celsius) Temperature Figure 5.8. Temperature Sensor Transfer Function 5.6.1. Calibration The uncalibrated temperature sensor output is extremely linear and suitable for relative temperature measurements (see Table 4.10 for linearity specifications). For absolute temperature measurements, offset and/or gain calibration is recommended. Typically a 1-point (offset) calibration includes the following steps: 1. Control/measure the ambient temperature (this temperature must be known). 2. Power the device, and delay for a few seconds to allow for self-heating. 3. Perform an ADC conversion with the temperature sensor selected as the positive input and GND Rev. 1.0 97 Si106x/108x selected as the negative input. 4. Calculate the offset characteristics, and store this value in non-volatile memory for use with subsequent temperature sensor measurements. Figure 5.9 shows the typical temperature sensor error assuming a 1-point calibration at 25 C. Parameters that affect ADC measurement, in particular the voltage reference value, will also affect temperature measurement. Error (degrees C) A single-point offset measurement of the temperature sensor is performed on each device during production test. The measurement is performed at 25 C 5 C, using the ADC with the internal high speed reference buffer selected as the Voltage Reference. The direct ADC result of the measurement is stored in the SFR registers TOFFH and TOFFL, shown in SFR Definition 5.13 and SFR Definition 5.14. 5.00 5.00 4.00 4.00 3.00 3.00 2.00 2.00 1.00 1.00 0.00 -40.00 -20.00 0.00 40.00 20.00 60.00 80.00 0.00 -1.00 -1.00 -2.00 -2.00 -3.00 -3.00 -4.00 -4.00 -5.00 -5.00 Temperature (degrees C) Figure 5.9. Temperature Sensor Error with 1-Point Calibration (VREF = 1.68 V) 98 Rev. 1.0 Si106x/108x SFR Definition 5.13. TOFFH: ADC0 Data Word High Byte Bit 7 6 5 4 3 2 1 0 TOFF[9:2] Name Type R R R R R R R R Reset Varies Varies Varies Varies Varies Varies Varies Varies SFR Page = 0xF; SFR Address = 0x86 Bit Name 7:0 TOFF[9:2] Function Temperature Sensor Offset High Bits. Most Significant Bits of the 10-bit temperature sensor offset measurement. SFR Definition 5.14. TOFFL: ADC0 Data Word Low Byte Bit 7 6 5 4 3 2 1 0 0 0 0 0 0 0 TOFF[1:0] Name Type R R Reset Varies Varies SFR Page = 0xF; SFR Address = 0x85 Bit Name 7:6 TOFF[1:0] Function Temperature Sensor Offset Low Bits. Least Significant Bits of the 10-bit temperature sensor offset measurement. 5:0 Unused Read = 0; Write = Don't Care. Rev. 1.0 99 Si106x/108x 5.7. Voltage and Ground Reference Options The voltage reference MUX is configurable to use an externally connected voltage reference, one of two internal voltage references, or one of two power supply voltages (see Figure 5.10). The ground reference MUX allows the ground reference for ADC0 to be selected between the ground pin (GND) or a port pin dedicated to analog ground (P0.1/AGND). The voltage and ground reference options are configured using the REF0CN SFR described on page 102. Electrical specifications are can be found in the Electrical Specifications Chapter. Important Note About the VREF and AGND Inputs: Port pins are used as the external VREF and AGND inputs. When using an external voltage reference or the internal precision reference, P0.0/VREF should be configured as an analog input and skipped by the Digital Crossbar. When using AGND as the ground reference to ADC0, P0.1/AGND should be configured as an analog input and skipped by the Digital Crossbar. Refer to Section "20. Si106x/108xPort Input/Output" on page 217 for complete Port I/O configuration details. The external reference voltage must be within the range 0 VREF VDD_MCU and the external ground reference must be at the same DC voltage potential as GND. REFOE REFGND REFSL1 REFSL0 TEMPE R E F 0C N T em p S ensor EN ADC Input M ux REFOE EN VDD R1 E xternal V oltage R eference C ircuit Internal 1.68V R eference P 0 .0/V R E F 00 V D D /D C + 01 Internal 1.8V R egulated D igital S upply GND 10 VREF (to A D C ) 11 4 .7 F + 0 .1 F R ecom m ended B ypass C apacitors Internal 1.65 V H igh S peed R eference GND 0 P 0.1/A G N D 1 G round (to A D C ) REFGND Figure 5.10. Voltage Reference Functional Block Diagram Rev. 1.0 100 Si106x/108x 5.8. External Voltage References To use an external voltage reference, REFSL[1:0] should be set to 00 and the internal 1.68 V precision reference should be disabled by setting REFOE to 0. Bypass capacitors should be added as recommended by the manufacturer of the external voltage reference. 5.9. Internal Voltage References For applications requiring the maximum number of port I/O pins, or very short VREF turn-on time, the 1.65 V high-speed reference will be the best internal reference option to choose. The high speed internal reference is selected by setting REFSL[1:0] to 11. When selected, the high speed internal reference will be automatically enabled/disabled on an as-needed basis by ADC0. For applications requiring the highest absolute accuracy, the 1.68 V precision voltage reference will be the best internal reference option to choose. The 1.68 V precision reference may be enabled and selected by setting REFOE to 1 and REFSL[1:0] to 00. An external capacitor of at least 0.1 F is recommended when using the precision voltage reference. In applications that leave the precision internal oscillator always running, there is no additional power required to use the precision voltage reference. In all other applications, using the high speed reference will result in lower overall power consumption due to its minimal startup time and the fact that it remains in a low power state when an ADC conversion is not taking place. Note: When using the precision internal oscillator as the system clock source, the precision voltage reference should not be enabled from a disabled state. To use the precision oscillator and the precision voltage reference simultaneously, the precision voltage reference should be enabled first and allowed to settle to its final value (charging the external capacitor) before the precision oscillator is started and selected as the system clock. For applications with a non-varying power supply voltage, using the power supply as the voltage reference can provide ADC0 with added dynamic range at the cost of reduced power supply noise rejection. To use the 1.8 to 3.6 V power supply voltage (VDD_MCU) or the 1.8 V regulated digital supply voltage as the reference source, REFSL[1:0] should be set to 01 or 10, respectively. 5.10. Analog Ground Reference To prevent ground noise generated by switching digital logic from affecting sensitive analog measurements, a separate analog ground reference option is available. When enabled, the ground reference for ADC0 during both the tracking/sampling and the conversion periods is taken from the P0.1/AGND pin. Any external sensors sampled by ADC0 should be referenced to the P0.1/AGND pin. This pin should be connected to the ground terminal of any external sensors sampled by ADC0. If an external voltage reference is used, the P0.1/AGND pin should be connected to the ground of the external reference and its associated decoupling capacitor. If the 1.68 V precision internal reference is used, then P0.1/AGND should be connected to the ground terminal of its external decoupling capacitor. The separate analog ground reference option is enabled by setting REFGND to 1. Note that when sampling the internal temperature sensor, the internal device ground is always used for the sampling operation, regardless of the setting of the REFGND bit. Similarly, whenever the internal 1.65 V high-speed reference is selected, the internal device ground is always used during the conversion period, regardless of the setting of the REFGND bit. 5.11. Temperature Sensor Enable The TEMPE bit in register REF0CN enables/disables the temperature sensor. While disabled, the temperature sensor defaults to a high impedance state and any ADC0 measurements performed on the sensor result in meaningless data. See Section "5.6. Temperature Sensor" on page 97 for details on temperature sensor characteristics when it is enabled. 101 Rev. 1.0 Si106x/108x SFR Definition 5.15. REF0CN: Voltage Reference Control Bit 7 6 5 4 REFGND Name 3 REFSL 2 1 TEMPE 0 REFOE Type R R R/W R/W R/W R/W R R/W Reset 0 0 0 1 1 0 0 0 SFR Page = 0x0; SFR Address = 0xD1 Bit Name 7:6 5 Unused Function Read = 00b; Write = Don't Care. REFGND Analog Ground Reference. Selects the ADC0 ground reference. 0: The ADC0 ground reference is the GND pin. 1: The ADC0 ground reference is the P0.1/AGND pin. 4:3 REFSL Voltage Reference Select. Selects the ADC0 voltage reference. 00: The ADC0 voltage reference is the P0.0/VREF pin. 01: The ADC0 voltage reference is the VDD_MCU pin. 10: The ADC0 voltage reference is the internal 1.8 V digital supply voltage. 11: The ADC0 voltage reference is the internal 1.65 V high speed voltage reference. 2 TEMPE Temperature Sensor Enable. Enables/Disables the internal temperature sensor. 0: Temperature Sensor Disabled. 1: Temperature Sensor Enabled. 1 Unused Read = 0b; Write = Don't Care. 0 REFOE Internal Voltage Reference Output Enable. Connects/Disconnects the internal voltage reference to the P0.0/VREF pin. 0: Internal 1.68 V Precision Voltage Reference disabled and not connected to P0.0/VREF. 1: Internal 1.68 V Precision Voltage Reference enabled and connected to P0.0/VREF. 5.12. Voltage Reference Electrical Specifications See Table 4.11 on page 62 for detailed Voltage Reference Electrical Specifications. Rev. 1.0 102 Si106x/108x 6. Comparators Si106x/108x devices include two on-chip programmable voltage comparators: Comparator 0 (CPT0) is shown in Figure 6.1; Comparator 1 (CPT1) is shown in Figure 6.2. The two comparators operate identically, but may differ in their ability to be used as reset or wake-up sources. See the Reset Sources chapter and the Power Management chapter for details on reset sources and low power mode wake-up sources, respectively. The Comparator offers programmable response time and hysteresis, an analog input multiplexer, and two outputs that are optionally available at the Port pins: a synchronous "latched" output (CP0, CP1), or an asynchronous "raw" output (CP0A, CP1A). The asynchronous CP0A signal is available even when the system clock is not active. This allows the Comparator to operate and generate an output when the device is in some low power modes. 6.1. Comparator Inputs Each Comparator performs an analog comparison of the voltage levels at its positive (CP0+ or CP1+) and negative (CP0- or CP1-) input. Both comparators support multiple port pin inputs multiplexed to their positive and negative comparator inputs using analog input multiplexers. The analog input multiplexers are completely under software control and configured using SFR registers. See Section "6.6. Comparator0 and Comparator1 Analog Multiplexers" on page 110 for details on how to select and configure Comparator inputs. Important Note About Comparator Inputs: The Port pins selected as Comparator inputs should be configured as analog inputs and skipped by the Crossbar. See the Port I/O chapter for more details on how to configure Port I/O pins as Analog Inputs. The Comparator may also be used to compare the logic level of digital signals, however, Port I/O pins configured as digital inputs must be driven to a valid logic state (HIGH or LOW) to avoid increased power consumption. CPT0CN CP0EN CP0OUT CP0RIF VDD CP0FIF CP0HYP1 CP0 Interrupt CP0HYP0 CP0HYN1 CP0HYN0 CPT0MD Analog Input Multiplexer CP0FIE CP0RIE CP0MD1 CP0MD0 Px.x CP0 Rising-edge CP0 + CP0 Falling-edge Interrupt Logic Px.x CP0 + D - SET CLR Q Q D SET CLR Q Q Px.x Crossbar (SYNCHRONIZER) CP0 - GND (ASYNCHRONOUS) Px.x CP0A Reset Decision Tree Figure 6.1. Comparator 0 Functional Block Diagram Rev. 1.0 103 Si106x/108x 6.2. Comparator Outputs When a comparator is enabled, its output is a logic 1 if the voltage at the positive input is higher than the voltage at the negative input. When disabled, the comparator output is a logic 0. The comparator output is synchronized with the system clock as shown in Figure 6.2. The synchronous "latched" output (CP0, CP1) can be polled in software (CPnOUT bit), used as an interrupt source, or routed to a Port pin through the Crossbar. The asynchronous "raw" comparator output (CP0A, CP1A) is used by the low power mode wakeup logic and reset decision logic. See the Power Options chapter and the Reset Sources chapter for more details on how the asynchronous comparator outputs are used to make wake-up and reset decisions. The asynchronous comparator output can also be routed directly to a Port pin through the Crossbar, and is available for use outside the device even if the system clock is stopped. When using a Comparator as an interrupt source, Comparator interrupts can be generated on rising-edge and/or falling-edge comparator output transitions. Two independent interrupt flags (CPnRIF and CPnFIF) allow software to determine which edge caused the Comparator interrupt. The comparator rising-edge and falling-edge interrupt flags are set by hardware when a corresponding edge is detected regardless of the interrupt enable state. Once set, these bits remain set until cleared by software. The rising-edge and falling-edge interrupts can be individually enabled using the CPnRIE and CPnFIE interrupt enable bits in the CPTnMD register. In order for the CPnRIF and/or CPnFIF interrupt flags to generate an interrupt request to the CPU, the Comparator must be enabled as an interrupt source and global interrupts must be enabled. See the Interrupt Handler chapter for additional information. CPT0CN CP1EN CP1OUT CP1RIF VDD CP1FIF CP1HYP1 CP1 Interrupt CP1HYP0 CP1HYN1 CP1HYN0 CPT0MD Analog Input Multiplexer CP1FIE CP1RIE CP1MD1 CP1MD0 Px.x CP1 Rising-edge CP1 + CP1 Falling-edge Interrupt Logic Px.x CP1 + D - SET CLR Q Q D SET CLR Q Q Px.x Crossbar (SYNCHRONIZER) CP1 - GND (ASYNCHRONOUS) Reset Decision Tree Px.x Figure 6.2. Comparator 1 Functional Block Diagram 104 Rev. 1.0 CP1A Si106x/108x 6.3. Comparator Response Time Comparator response time may be configured in software via the CPTnMD registers described on "CPT0MD: Comparator 0 Mode Selection" on page 107 and "CPT1MD: Comparator 1 Mode Selection" on page 109. Four response time settings are available: Mode 0 (Fastest Response Time), Mode 1, Mode 2, and Mode 3 (Lowest Power). Selecting a longer response time reduces the Comparator active supply current. The Comparators also have low power shutdown state, which is entered any time the comparator is disabled. Comparator rising edge and falling edge response times are typically not equal. See Table 4.12 on page 63 for complete comparator timing and supply current specifications. 6.4. Comparator Hysteresis The Comparators feature software-programmable hysteresis that can be used to stabilize the comparator output while a transition is occurring on the input. Using the CPTnCN registers, the user can program both the amount of hysteresis voltage (referred to the input voltage) and the positive and negative-going symmetry of this hysteresis around the threshold voltage (i.e., the comparator negative input). Figure 6.3 shows that when positive hysteresis is enabled, the comparator output does not transition from logic 0 to logic 1 until the comparator positive input voltage has exceeded the threshold voltage by an amount equal to the programmed hysteresis. It also shows that when negative hysteresis is enabled, the comparator output does not transition from logic 1 to logic 0 until the comparator positive input voltage has fallen below the threshold voltage by an amount equal to the programmed hysteresis. The amount of positive hysteresis is determined by the settings of the CPnHYP bits in the CPTnCN register and the amount of negative hysteresis voltage is determined by the settings of the CPnHYN bits in the same register. Settings of 20, 10, 5, or 0 mV can be programmed for both positive and negative hysteresis. See Section "Table 4.12. Comparator Electrical Characteristics" on page 63 for complete comparator hysteresis specifications. VIN+ VIN- CPn+ CPn- + CPn _ OUT CIRCUIT CONFIGURATION Positive Hysteresis Voltage (Programmed with CP0HYP Bits) VIN- INPUTS Negative Hysteresis Voltage (Programmed by CP0HYN Bits) VIN+ V OH OUTPUT V OL Negative Hysteresis Disabled Positive Hysteresis Disabled Maximum Negative Hysteresis Maximum Positive Hysteresis Figure 6.3. Comparator Hysteresis Plot Rev. 1.0 105 Si106x/108x 6.5. Comparator Register Descriptions The SFRs used to enable and configure the comparators are described in the following register descriptions. A Comparator must be enabled by setting the CPnEN bit to logic 1 before it can be used. From an enabled state, a comparator can be disabled and placed in a low power state by clearing the CPnEN bit to logic 0. Important Note About Comparator Settings: False rising and falling edges can be detected by the Comparator while powering on or if changes are made to the hysteresis or response time control bits. Therefore, it is recommended that the rising-edge and falling-edge flags be explicitly cleared to logic 0 a short time after the comparator is enabled or its mode bits have been changed. The Comparator Power Up Time is specified in Section "Table 4.12. Comparator Electrical Characteristics" on page 63. SFR Definition 6.1. CPT0CN: Comparator 0 Control Bit 7 6 5 4 Name CP0EN CP0OUT CP0RIF CP0FIF CP0HYP[1:0] CP0HYN[1:0] Type R/W R R/W R/W R/W R/W Reset 0 0 0 0 SFR Page= 0x0; SFR Address = 0x9B Bit Name 7 CP0EN 3 2 0 0 1 0 0 0 Function Comparator0 Enable Bit. 0: Comparator0 Disabled. 1: Comparator0 Enabled. 6 CP0OUT Comparator0 Output State Flag. 0: Voltage on CP0+ < CP0-. 1: Voltage on CP0+ > CP0-. 5 CP0RIF Comparator0 Rising-Edge Flag. Must be cleared by software. 0: No Comparator0 Rising Edge has occurred since this flag was last cleared. 1: Comparator0 Rising Edge has occurred. 4 CP0FIF Comparator0 Falling-Edge Flag. Must be cleared by software. 0: No Comparator0 Falling-Edge has occurred since this flag was last cleared. 1: Comparator0 Falling-Edge has occurred. 3:2 CP0HYP[1:0] Comparator0 Positive Hysteresis Control Bits. 00: Positive Hysteresis Disabled. 01: Positive Hysteresis = 5 mV. 10: Positive Hysteresis = 10 mV. 11: Positive Hysteresis = 20 mV. 1:0 CP0HYN[1:0] Comparator0 Negative Hysteresis Control Bits. 00: Negative Hysteresis Disabled. 01: Negative Hysteresis = 5 mV. 10: Negative Hysteresis = 10 mV. 11: Negative Hysteresis = 20 mV. 106 Rev. 1.0 Si106x/108x SFR Definition 6.2. CPT0MD: Comparator 0 Mode Selection Bit 7 6 Name 5 4 CP0RIE CP0FIE 3 2 R/W R R/W R/W R R Reset 1 0 0 0 0 0 R/W 1 0 Function 7 Reserved 6 Unused Read = 0b, Write = don't care. 5 CP0RIE Comparator0 Rising-Edge Interrupt Enable. 0: Comparator0 Rising-edge interrupt disabled. 1: Comparator0 Rising-edge interrupt enabled. 4 CP0FIE Comparator0 Falling-Edge Interrupt Enable. 0: Comparator0 Falling-edge interrupt disabled. 1: Comparator0 Falling-edge interrupt enabled. 3:2 Unused Read = 00b, Write = don't care. 1:0 0 CP0MD[1:0] Type SFR Page = All Pages; SFR Address = 0x9D Bit Name 1 Read = 1b, Must Write 1b. CP0MD[1:0] Comparator0 Mode Select. These bits affect the response time and power consumption for Comparator0. 00: Mode 0 (Fastest Response Time, Highest Power Consumption) 01: Mode 1 10: Mode 2 11: Mode 3 (Slowest Response Time, Lowest Power Consumption) Rev. 1.0 107 Si106x/108x SFR Definition 6.3. CPT1CN: Comparator 1 Control Bit 7 6 5 4 Name CP1EN CP1OUT CP1RIF CP1FIF CP1HYP[1:0] CP1HYN[1:0] Type R/W R R/W R/W R/W R/W Reset 0 0 0 0 SFR Page= 0x0; SFR Address = 0x9A Bit Name 7 CP1EN 3 2 0 0 1 0 0 0 Function Comparator1 Enable Bit. 0: Comparator1 Disabled. 1: Comparator1 Enabled. 6 CP1OUT Comparator1 Output State Flag. 0: Voltage on CP1+ < CP1-. 1: Voltage on CP1+ > CP1-. 5 CP1RIF Comparator1 Rising-Edge Flag. Must be cleared by software. 0: No Comparator1 Rising Edge has occurred since this flag was last cleared. 1: Comparator1 Rising Edge has occurred. 4 CP1FIF Comparator1 Falling-Edge Flag. Must be cleared by software. 0: No Comparator1 Falling-Edge has occurred since this flag was last cleared. 1: Comparator1 Falling-Edge has occurred. 3:2 CP1HYP[1:0] Comparator1 Positive Hysteresis Control Bits. 00: Positive Hysteresis Disabled. 01: Positive Hysteresis = 5 mV. 10: Positive Hysteresis = 10 mV. 11: Positive Hysteresis = 20 mV. 1:0 CP1HYN[1:0] Comparator1 Negative Hysteresis Control Bits. 00: Negative Hysteresis Disabled. 01: Negative Hysteresis = 5 mV. 10: Negative Hysteresis = 10 mV. 11: Negative Hysteresis = 20 mV. 108 Rev. 1.0 Si106x/108x SFR Definition 6.4. CPT1MD: Comparator 1 Mode Selection Bit 7 6 Name 5 4 CP1RIE CP1FIE 3 2 R/W R R/W R/W R R Reset 1 0 0 0 0 0 R/W 1 0 Function 7 Reserved 6 Unused Read = 00b, Write = don't care. 5 CP1RIE Comparator1 Rising-Edge Interrupt Enable. 0: Comparator1 Rising-edge interrupt disabled. 1: Comparator1 Rising-edge interrupt enabled. 4 CP1FIE Comparator1 Falling-Edge Interrupt Enable. 0: Comparator1 Falling-edge interrupt disabled. 1: Comparator1 Falling-edge interrupt enabled. 3:2 Unused Read = 00b, Write = don't care. 1:0 0 CP1MD[1:0] Type SFR Page = 0x0; SFR Address = 0x9C Bit Name 1 Read = 1b, Must Write 1b. CP1MD[1:0] Comparator1 Mode Select These bits affect the response time and power consumption for Comparator1. 00: Mode 0 (Fastest Response Time, Highest Power Consumption) 01: Mode 1 10: Mode 2 11: Mode 3 (Slowest Response Time, Lowest Power Consumption) Rev. 1.0 109 Si106x/108x 6.6. Comparator0 and Comparator1 Analog Multiplexers Comparator0 and Comparator1 on Si106x/108x devices have analog input multiplexers to connect Port I/O pins and internal signals the comparator inputs; CP0+/CP0- are the positive and negative input multiplexers for Comparator0 and CP1+/CP1- are the positive and negative input multiplexers for Comparator1. The comparator input multiplexers directly support capacitive touch switches. When the Capacitive Touch Sense Compare input is selected on the positive or negative multiplexer, any Port I/O pin connected to the other multiplexer can be directly connected to a capacitive touch switch with no additional external components. The Capacitive Touch Sense Compare provides the appropriate reference level for detecting when the capacitive touch switches have charged or discharged through the on-chip Rsense resistor. The Comparator outputs can be routed to Timer2 or Timer3 for capturing sense capacitor's charge and discharge time. See Section "31. Timers" on page 311 for details. See Application Note AN338 for details on Capacitive Touch Switch sensing. Any of the following may be selected as comparator inputs: Port I/O pins, Capacitive Touch Sense Compare, VDD_MCU Supply Voltage, Regulated Digital Supply Voltage (Output of VREG0) or ground. The Comparator's supply voltage divided by 2 is also available as an input; the resistors used to divide the voltage only draw current when this setting is selected. The Comparator input multiplexers are configured using the CPT0MX and CPT1MX registers described in SFR Definition 6.5 and SFR Definition 6.6. CMXnN3 CMXnN2 CMXnN1 CMXnN0 CMXnP3 CMXnP2 CMXnP1 CMXnP0 CPTnMX P0.1 P0.3 P0.5 P0.7 CPnOUT P1.5 P1.7 P2.1 P2.3 P2.5 VDD_MCU CPnOUT R R R R CPnOUT Rsense Capacitive Touch Sense Compare (1/3 or 2/3) x VDD_MCU VDD_MCU R P0.0 P0.2 P0.4 P0.6 P1.6 P2.0 P2.2 P2.4 P2.6 Capacitive VDD_MCU CPnOUT Touch Sense R R Compare (1/3 or 2/3) x VDD_MCU R Rsense Only enabled when Capacitive Touch Sense Compare is selected on CPn+ Input MUX. CPnInput MUX CPn+ Input MUX VDD_MCU 1/2 x VDD_MCU Digital Supply R R Only enabled when Capacitive Touch Sense Compare is selected on CPnInput MUX. VDD_MCU + GND 1/2 x VDD_MCU VBAT VDD_MCU GND Figure 6.4. CPn Multiplexer Block Diagram Important Note About Comparator Input Configuration: Port pins selected as comparator inputs should be configured as analog inputs, and should be skipped by the Digital Crossbar. To configure a Port pin for analog input, set to 0 the corresponding bit in register PnMDIN and disable the digital driver (PnMDOUT = 0 and Port Latch = 1). To force the Crossbar to skip a Port pin, set to 1 the corresponding bit in register PnSKIP. See Section "20. Si106x/108xPort Input/Output" on page 217 for more Port I/O configuration details. Rev. 1.0 110 Si106x/108x SFR Definition 6.5. CPT0MX: Comparator0 Input Channel Select Bit 7 6 5 4 3 CMX0N[3:0] Name 2 1 0 CMX0P[3:0] Type R/W R/W R/W R/W R/W R/W R/W R/W Reset 1 1 1 1 1 1 1 1 SFR Page = 0x0; SFR Address = 0x9F Bit Name 7:4 3:0 111 CMX0N CMX0P Function Comparator0 Negative Input Selection. Selects the negative input channel for Comparator0. 0000: P0.1 1000: P2.1 0001: P0.3 1001: P2.3 0010: P0.5 1010: P2.5 0011: P0.7 1011: Reserved 0100: Reserved 1100: Capacitive Touch Sense Compare 0101: Reserved 1101: VDD_MCU divided by 2 0110: P1.5 1110: Digital Supply Voltage 0111: P1.7 1111: Ground Comparator0 Positive Input Selection. Selects the positive input channel for Comparator0. 0000: P0.0 1000: P2.0 0001: P0.2 1001: P2.2 0010: P0.4 1010: P2.4 0011: P0.6 1011: P2.6 0100: Reserved 1100: Capacitive Touch Sense Compare 0101: Reserved 1101: VDD_MCU divided by 2 0110: Reserved 1110: VBAT Supply Voltage 0111: P1.6 1111: VDD_MCU Supply Voltage Rev. 1.0 Si106x/108x SFR Definition 6.6. CPT1MX: Comparator1 Input Channel Select Bit 7 6 5 4 3 CMX1N[3:0] Name 2 1 0 CMX1P[3:0] Type R/W R/W R/W R/W R/W R/W R/W R/W Reset 1 1 1 1 1 1 1 1 SFR Page = 0x0; SFR Address = 0x9E Bit Name 7:4 3:0 CMX1N CMX1P Function Comparator1 Negative Input Selection. Selects the negative input channel for Comparator1. 0000: P0.1 1000: P2.1 0001: P0.3 1001: P2.3 0010: P0.5 1010: P2.5 0011: P0.7 1011: Reserved 0100: Reserved 1100: Capacitive Touch Sense Compare 0101: Reserved 1101: VDD_MCU divided by 2 0110: P1.5 1110: Digital Supply Voltage 0111: P1.7 1111: Ground Comparator1 Positive Input Selection. Selects the positive input channel for Comparator1. 0000: P0.0 1000: P2.0 0001: P0.2 1001: P2.2 0010: P0.4 1010: P2.4 0011: P0.6 1011: P2.6 0100: Reserved 1100: Capacitive Touch Sense Compare 0101: Reserved 1101: VDD_MCU divided by 2 0110: Reserved 1110: VBAT Supply Voltage 0111: P1.6 1111: VDD_MCU Supply Voltage Rev. 1.0 112 Si106x/108x 7. CIP-51 Microcontroller The MCU system controller core is the CIP-51 microcontroller. The CIP-51 is fully compatible with the MCS-51TM instruction set; standard 803x/805x assemblers and compilers can be used to develop software. The MCU family has a superset of all the peripherals included with a standard 8051. The CIP-51 also includes on-chip debug hardware (see description in Section 33), and interfaces directly with the analog and digital subsystems providing a complete data acquisition or control-system solution in a single integrated circuit. The CIP-51 Microcontroller core implements the standard 8051 organization and peripherals as well as additional custom peripherals and functions to extend its capability (see Figure 7.1 for a block diagram). The CIP-51 includes the following features: Fully Compatible with MCS-51 Instruction Set 25 MIPS Peak Throughput with 25 MHz Clock 0 to 25 MHz Clock Frequency Extended Interrupt Handler Reset Input Power Management Modes On-chip Debug Logic Program and Data Memory Security 7.1. Performance The CIP-51 employs a pipelined architecture that greatly increases its instruction throughput over the standard 8051 architecture. In a standard 8051, all instructions except for MUL and DIV take 12 or 24 system clock cycles to execute, and usually have a maximum system clock of 12 MHz. By contrast, the CIP-51 core executes 70% of its instructions in one or two system clock cycles, with no instructions taking more than eight system clock cycles. DATA BUS D8 TMP2 B REGISTER STACK POINTER SRAM ADDRESS REGISTER PSW D8 D8 D8 ALU SRAM D8 D8 TMP1 ACCUMULATOR D8 D8 D8 DATA BUS DATA BUS SFR_ADDRESS BUFFER D8 D8 DATA POINTER D8 SFR BUS INTERFACE SFR_CONTROL SFR_WRITE_DATA SFR_READ_DATA DATA BUS PC INCREMENTER PROGRAM COUNTER (PC) PRGM. ADDRESS REG. PIPELINE RESET MEM_CONTROL A16 MEMORY INTERFACE MEM_READ_DATA SYSTEM_IRQs D8 STOP POWER CONTROL REGISTER MEM_WRITE_DATA D8 CONTROL LOGIC CLOCK IDLE MEM_ADDRESS D8 INTERRUPT INTERFACE EMULATION_IRQ D8 Figure 7.1. CIP-51 Block Diagram Rev. 1.0 113 Si106x/108x With the CIP-51's maximum system clock at 25 MHz, it has a peak throughput of 25 MIPS. The CIP-51 has a total of 109 instructions. The table below shows the total number of instructions that require each execution time. Clocks to Execute 1 2 2/3 3 3/4 4 4/5 5 8 Number of Instructions 26 50 5 14 7 3 1 2 1 7.2. Programming and Debugging Support In-system programming of the flash program memory and communication with on-chip debug support logic is accomplished via the Silicon Labs 2-Wire Development Interface (C2). The on-chip debug support logic facilitates full speed in-circuit debugging, allowing the setting of hardware breakpoints, starting, stopping and single stepping through program execution (including interrupt service routines), examination of the program's call stack, and reading/writing the contents of registers and memory. This method of on-chip debugging is completely non-intrusive, requiring no RAM, Stack, timers, or other on-chip resources. C2 details can be found in Section "33. Device Specific Behavior" on page 352. The CIP-51 is supported by development tools from Silicon Labs and third party vendors. Silicon Labs provides an integrated development environment (IDE) including editor, debugger and programmer. The IDE's debugger and programmer interface to the CIP-51 via the C2 interface to provide fast and efficient in-system device programming and debugging. Third party macro assemblers and C compilers are also available. 7.3. Instruction Set The instruction set of the CIP-51 System Controller is fully compatible with the standard MCS-51TM instruction set. Standard 8051 development tools can be used to develop software for the CIP-51. All CIP-51 instructions are the binary and functional equivalent of their MCS-51TM counterparts, including opcodes, addressing modes and effect on PSW flags. However, instruction timing is different than that of the standard 8051. 7.3.1. Instruction and CPU Timing In many 8051 implementations, a distinction is made between machine cycles and clock cycles, with machine cycles varying from 2 to 12 clock cycles in length. However, the CIP-51 implementation is based solely on clock cycle timing. All instruction timings are specified in terms of clock cycles. Due to the pipelined architecture of the CIP-51, most instructions execute in the same number of clock cycles as there are program bytes in the instruction. Conditional branch instructions take one less clock cycle to complete when the branch is not taken as opposed to when the branch is taken. Table 7.1 is the CIP-51 Instruction Set Summary, which includes the mnemonic, number of bytes, and number of clock cycles for each instruction. 114 Rev. 1.0 Si106x/108x Table 7.1. CIP-51 Instruction Set Summary Mnemonic Description Bytes Clock Cycles Add register to A Add direct byte to A Add indirect RAM to A Add immediate to A Add register to A with carry Add direct byte to A with carry Add indirect RAM to A with carry Add immediate to A with carry Subtract register from A with borrow Subtract direct byte from A with borrow Subtract indirect RAM from A with borrow Subtract immediate from A with borrow Increment A Increment register Increment direct byte Increment indirect RAM Decrement A Decrement register Decrement direct byte Decrement indirect RAM Increment Data Pointer Multiply A and B Divide A by B Decimal adjust A 1 2 1 2 1 2 1 2 1 2 1 2 1 1 2 1 1 1 2 1 1 1 1 1 1 2 2 2 1 2 2 2 1 2 2 2 1 1 2 2 1 1 2 2 1 4 8 1 AND Register to A AND direct byte to A AND indirect RAM to A AND immediate to A AND A to direct byte AND immediate to direct byte OR Register to A OR direct byte to A OR indirect RAM to A OR immediate to A OR A to direct byte OR immediate to direct byte Exclusive-OR Register to A Exclusive-OR direct byte to A Exclusive-OR indirect RAM to A Exclusive-OR immediate to A Exclusive-OR A to direct byte 1 2 1 2 2 3 1 2 1 2 2 3 1 2 1 2 2 1 2 2 2 2 3 1 2 2 2 2 3 1 2 2 2 2 Arithmetic Operations ADD A, Rn ADD A, direct ADD A, @Ri ADD A, #data ADDC A, Rn ADDC A, direct ADDC A, @Ri ADDC A, #data SUBB A, Rn SUBB A, direct SUBB A, @Ri SUBB A, #data INC A INC Rn INC direct INC @Ri DEC A DEC Rn DEC direct DEC @Ri INC DPTR MUL AB DIV AB DA A Logical Operations ANL A, Rn ANL A, direct ANL A, @Ri ANL A, #data ANL direct, A ANL direct, #data ORL A, Rn ORL A, direct ORL A, @Ri ORL A, #data ORL direct, A ORL direct, #data XRL A, Rn XRL A, direct XRL A, @Ri XRL A, #data XRL direct, A Rev. 1.0 115 Si106x/108x Table 7.1. CIP-51 Instruction Set Summary (Continued) Mnemonic XRL direct, #data CLR A CPL A RL A RLC A RR A RRC A SWAP A Description Bytes Clock Cycles Exclusive-OR immediate to direct byte Clear A Complement A Rotate A left Rotate A left through Carry Rotate A right Rotate A right through Carry Swap nibbles of A 3 1 1 1 1 1 1 1 3 1 1 1 1 1 1 1 Move Register to A Move direct byte to A Move indirect RAM to A Move immediate to A Move A to Register Move direct byte to Register Move immediate to Register Move A to direct byte Move Register to direct byte Move direct byte to direct byte Move indirect RAM to direct byte Move immediate to direct byte Move A to indirect RAM Move direct byte to indirect RAM Move immediate to indirect RAM Load DPTR with 16-bit constant Move code byte relative DPTR to A Move code byte relative PC to A Move external data (8-bit address) to A Move A to external data (8-bit address) Move external data (16-bit address) to A Move A to external data (16-bit address) Push direct byte onto stack Pop direct byte from stack Exchange Register with A Exchange direct byte with A Exchange indirect RAM with A Exchange low nibble of indirect RAM with A 1 2 1 2 1 2 2 2 2 3 2 3 1 2 2 3 1 1 1 1 1 1 2 2 1 2 1 1 1 2 2 2 1 2 2 2 2 3 2 3 2 2 2 3 3 3 3 3 3 3 2 2 1 2 2 2 Clear Carry Clear direct bit Set Carry Set direct bit Complement Carry Complement direct bit 1 2 1 2 1 2 1 2 1 2 1 2 Data Transfer MOV A, Rn MOV A, direct MOV A, @Ri MOV A, #data MOV Rn, A MOV Rn, direct MOV Rn, #data MOV direct, A MOV direct, Rn MOV direct, direct MOV direct, @Ri MOV direct, #data MOV @Ri, A MOV @Ri, direct MOV @Ri, #data MOV DPTR, #data16 MOVC A, @A+DPTR MOVC A, @A+PC MOVX A, @Ri MOVX @Ri, A MOVX A, @DPTR MOVX @DPTR, A PUSH direct POP direct XCH A, Rn XCH A, direct XCH A, @Ri XCHD A, @Ri Boolean Manipulation CLR C CLR bit SETB C SETB bit CPL C CPL bit 116 Rev. 1.0 Si106x/108x Table 7.1. CIP-51 Instruction Set Summary (Continued) Mnemonic ANL C, bit ANL C, /bit ORL C, bit ORL C, /bit MOV C, bit MOV bit, C JC rel JNC rel JB bit, rel JNB bit, rel JBC bit, rel Description Bytes Clock Cycles AND direct bit to Carry AND complement of direct bit to Carry OR direct bit to carry OR complement of direct bit to Carry Move direct bit to Carry Move Carry to direct bit Jump if Carry is set Jump if Carry is not set Jump if direct bit is set Jump if direct bit is not set Jump if direct bit is set and clear bit 2 2 2 2 2 2 2 2 3 3 3 2 2 2 2 2 2 2/3 2/3 3/4 3/4 3/4 Absolute subroutine call Long subroutine call Return from subroutine Return from interrupt Absolute jump Long jump Short jump (relative address) Jump indirect relative to DPTR Jump if A equals zero Jump if A does not equal zero Compare direct byte to A and jump if not equal Compare immediate to A and jump if not equal Compare immediate to Register and jump if not equal Compare immediate to indirect and jump if not equal Decrement Register and jump if not zero Decrement direct byte and jump if not zero No operation 2 3 1 1 2 3 2 1 2 2 3 3 3 3 4 5 5 3 4 3 3 2/3 2/3 4/5 3/4 3/4 3 4/5 2 3 1 2/3 3/4 1 Program Branching ACALL addr11 LCALL addr16 RET RETI AJMP addr11 LJMP addr16 SJMP rel JMP @A+DPTR JZ rel JNZ rel CJNE A, direct, rel CJNE A, #data, rel CJNE Rn, #data, rel CJNE @Ri, #data, rel DJNZ Rn, rel DJNZ direct, rel NOP Rev. 1.0 117 Si106x/108x Notes on Registers, Operands and Addressing Modes: Rn - Register R0-R7 of the currently selected register bank. @Ri - Data RAM location addressed indirectly through R0 or R1. rel - 8-bit, signed (twos complement) offset relative to the first byte of the following instruction. Used by SJMP and all conditional jumps. direct - 8-bit internal data location's address. This could be a direct-access Data RAM location (0x00- 0x7F) or an SFR (0x80-0xFF). #data - 8-bit constant #data16 - 16-bit constant bit - Direct-accessed bit in Data RAM or SFR addr11 - 11-bit destination address used by ACALL and AJMP. The destination must be within the same 2 kB page of program memory as the first byte of the following instruction. addr16 - 16-bit destination address used by LCALL and LJMP. The destination may be anywhere within the 8 kB program memory space. There is one unused opcode (0xA5) that performs the same function as NOP. All mnemonics copyrighted (c) Intel Corporation 1980. 118 Rev. 1.0 Si106x/108x 7.4. CIP-51 Register Descriptions Following are descriptions of SFRs related to the operation of the CIP-51 System Controller. Reserved bits should not be set to logic l. Future product versions may use these bits to implement new features in which case the reset value of the bit will be logic 0, selecting the feature's default state. Detailed descriptions of the remaining SFRs are included in the sections of the data sheet associated with their corresponding system function. SFR Definition 7.1. DPL: Data Pointer Low Byte Bit 7 6 5 4 Name DPL[7:0] Type R/W Reset 0 0 0 0 SFR Page = All Pages; SFR Address = 0x82 Bit Name 7:0 DPL[7:0] 3 2 1 0 0 0 0 0 Function Data Pointer Low. The DPL register is the low byte of the 16-bit DPTR. DPTR is used to access indirectly addressed flash memory or XRAM. SFR Definition 7.2. DPH: Data Pointer High Byte Bit 7 6 5 4 Name DPH[7:0] Type R/W Reset 0 0 0 0 SFR Page = All Pages; SFR Address = 0x83 Bit Name 7:0 DPH[7:0] 3 2 1 0 0 0 0 0 Function Data Pointer High. The DPH register is the high byte of the 16-bit DPTR. DPTR is used to access indirectly addressed flash memory or XRAM. Rev. 1.0 119 Si106x/108x SFR Definition 7.3. SP: Stack Pointer Bit 7 6 5 4 Name SP[7:0] Type R/W Reset 0 0 0 0 SFR Page = All Pages; SFR Address = 0x81 Bit Name 7:0 SP[7:0] 3 2 1 0 0 1 1 1 Function Stack Pointer. The Stack Pointer holds the location of the top of the stack. The stack pointer is incremented before every PUSH operation. The SP register defaults to 0x07 after reset. SFR Definition 7.4. ACC: Accumulator Bit 7 6 5 4 Name ACC[7:0] Type R/W Reset 0 0 0 0 3 2 1 0 0 0 0 0 SFR Page = All Pages; SFR Address = 0xE0; Bit-Addressable Bit Name Function 7:0 ACC[7:0] Accumulator. This register is the accumulator for arithmetic operations. SFR Definition 7.5. B: B Register Bit 7 6 5 4 Name B[7:0] Type R/W Reset 0 0 0 0 3 2 1 0 0 0 0 0 SFR Page = All Pages; SFR Address = 0xF0; Bit-Addressable Bit Name Function 7:0 B[7:0] B Register. This register serves as a second accumulator for certain arithmetic operations. 120 Rev. 1.0 Si106x/108x SFR Definition 7.6. PSW: Program Status Word Bit 7 6 5 Name CY AC F0 Type R/W R/W R/W Reset 0 0 0 4 3 2 1 0 RS[1:0] OV F1 PARITY R/W R/W R/W R 0 0 0 0 0 SFR Page = All Pages; SFR Address = 0xD0; Bit-Addressable Bit Name Function 7 CY Carry Flag. This bit is set when the last arithmetic operation resulted in a carry (addition) or a borrow (subtraction). It is cleared to logic 0 by all other arithmetic operations. 6 AC Auxiliary Carry Flag. This bit is set when the last arithmetic operation resulted in a carry into (addition) or a borrow from (subtraction) the high order nibble. It is cleared to logic 0 by all other arithmetic operations. 5 F0 User Flag 0. This is a bit-addressable, general purpose flag for use under software control. 4:3 RS[1:0] Register Bank Select. These bits select which register bank is used during register accesses. 00: Bank 0, Addresses 0x00-0x07 01: Bank 1, Addresses 0x08-0x0F 10: Bank 2, Addresses 0x10-0x17 11: Bank 3, Addresses 0x18-0x1F 2 OV Overflow Flag. This bit is set to 1 under the following circumstances: An ADD, ADDC, or SUBB instruction causes a sign-change overflow. A MUL instruction results in an overflow (result is greater than 255). A DIV instruction causes a divide-by-zero condition. The OV bit is cleared to 0 by the ADD, ADDC, SUBB, MUL, and DIV instructions in all other cases. 1 F1 User Flag 1. This is a bit-addressable, general purpose flag for use under software control. 0 PARITY Parity Flag. This bit is set to logic 1 if the sum of the eight bits in the accumulator is odd and cleared if the sum is even. Rev. 1.0 121 Si106x/108x 8. Memory Organization The memory organization of the CIP-51 System Controller is similar to that of a standard 8051. There are two separate memory spaces: program memory and data memory. Program and data memory share the same address space but are accessed via different instruction types. The memory organization of the Si106x device family is shown in Figure 8.1 and the Si108x device family is shown in Figure 8.2. PRO G RAM /DATA M EM O RY (FLASH) DATA M EM O RY (RA M ) IN TERNAL DATA ADDRESS SPACE Si1060/2/4 Upper 128 RAM 0x03FF 0x0000 0xFFFF Scrachpad M em ory (DATA only) RESERVED 0xFC 00 0xFBFF 64KB FLASH (In-System Program m able in 1024 Byte Sectors) Special Function Registers (Indirect Addressing O nly) (Direct Addressing O nly) 0 F (Direct and Indirect Addressing) Bit Addressable General Purpose Registers 0x0000 Lower 128 RAM (Direct and Indirect Addressing) EXTERNAL DATA ADDRESS SPACE Si1061/3/5 0x03FF 0x0000 0xFFFF Scrachpad M em ory (DATA only) R eserved 0x7FFF 0x1000 32KB FLASH 0x0FFF (In-System Program m able in 1024 Byte Sectors) XRAM - 4096 Bytes (accessable using M O VX instruction ) 0x0000 0x0000 Figure 8.1. Si106x Memory Map Rev. 1.0 122 Si106x/108x Figure 8.2. Si108x Memory Map 123 Rev. 1.0 Si106x/108x 8.1. Program Memory The CIP-51 core has a 64 kB program memory space. The Si106x implements 64 kB (Si1060/2/4) and 32 kB (Si1061/3/5) of this program memory space as in-system, re-programmable flash memory, organized in a contiguous block from addresses 0x0000 to 0xFBFF (Si1060/2/4) or 0x7FFF (Si1061/3/5). The address 0xFBFF (Si1060/2/4) or 0x7FFF (Si1061/3/5) serves as the security lock byte for the device. Any addresses above the lock byte are reserved. Si1060/2/4 (SFLE=0) Si1061/3/5 (SFLE=0) 0xFFFF 0xFFFF Reserved Area 0xFBFF 0xFBFE Lock Byte Page Unpopulated Address Space (Reserved) 0xF800 0xF7FF 0x8000 Lock Byte Si1060/2/4 Si1061/3/5 (SFLE=1) 0x7FFE Lock Byte Page Flash Memory Space 0x7C00 0x7BFF 0x03FF Scratchpad (Data Only) 0x7FFF 0x0000 FLASH memory organized in 1024-byte pages 0xFC00 Lock Byte Flash Memory Space 0x0000 0x0000 Figure 8.3. Si106x Flash Program Memory Map The Si108x implements 16 kB (Si1080/2/4) or 8 kB (Si1081/3/5) of this program memory space as in-system, re-programmable Flash memory, organized in a contiguous block from address 0x0000 to 0x3BFFF (Si1080/2/4) or 0x1FFF (Si1018/3/5). The last byte of this contiguous block of addresses serves as the security lock byte for the device. Any addresses above the lock byte are reserved. Figure 8.4. Si108x Flash Program Memory Map Rev. 1.0 124 Si106x/108x When creating applications that program their own Flash such as bootloaders, data loggers, etc, it is possible to write generic Flash management routines that operate on either 512 byte or 1024 byte Flash pages; however, this may not result in the most optimal memory usage. For example, in such a system, the logical Flash page size must be set to 1024 bytes. This can pose limitations on devices with a small Flash size. For example, an 8 kB device would only have 8 logical Flash pages. For larger Flash devices that have 1024 byte pages, each Flash page must be erased twice in order for the same code to support smaller devices that have 512 bytes per physical Flash page. In most applications, the most efficient method to support various devices is to use conditional compilation to tailor the Flash write/erase routines for each device. 8.1.1. MOVX Instruction and Program Memory The MOVX instruction in an 8051 device is typically used to access external data memory. On the Si106x/108x/S108x devices, the MOVX instruction is normally used to read and write on-chip XRAM, but can be re-configured to write and erase on-chip flash memory space. MOVC instructions are always used to read flash memory, while MOVX write instructions are used to erase and write flash. This flash access feature provides a mechanism for the Si106x/108x to update program code and use the program memory space for non-volatile data storage. Refer to Section "12. Flash Memory" on page 149 for further details. 8.2. Data Memory The Si106x/108x device family includes 4352 bytes of RAM data memory. 256 bytes of this memory is mapped into the internal RAM space of the 8051. 4096 bytes of this memory is on-chip "external" memory. The data memory map is shown in Figure 8.1 for reference. The Si108x device family include 768 bytes of RAM data memory. 256 bytes of this memory is mapped to the internal RAM space of the 8051. The remainder of this memory is on-chip "external" memory. The data memory map is shown in Figure 8.2 for reference. 8.2.1. Internal RAM There are 256 bytes of internal RAM mapped into the data memory space from 0x00 through 0xFF. The lower 128 bytes of data memory are used for general purpose registers and scratch pad memory. Either direct or indirect addressing may be used to access the lower 128 bytes of data memory. Locations 0x00 through 0x1F are addressable as four banks of general purpose registers, each bank consisting of eight byte-wide registers. The next 16 bytes, locations 0x20 through 0x2F, may either be addressed as bytes or as 128 bit locations accessible with the direct addressing mode. The upper 128 bytes of data memory are accessible only by indirect addressing. This region occupies the same address space as the Special Function Registers (SFR) but is physically separate from the SFR space. The addressing mode used by an instruction when accessing locations above 0x7F determines whether the CPU accesses the upper 128 bytes of data memory space or the SFRs. Instructions that use direct addressing will access the SFR space. Instructions using indirect addressing above 0x7F access the upper 128 bytes of data memory. Figure 8.1 and Figure 8.2 illustrate the data memory organization of the Si106x/108x and Si108x. 8.2.1.1. General Purpose Registers The lower 32 bytes of data memory, locations 0x00 through 0x1F, may be addressed as four banks of general-purpose registers. Each bank consists of eight byte-wide registers designated R0 through R7. Only one of these banks may be enabled at a time. Two bits in the program status word, RS0 (PSW.3) and RS1 (PSW.4), select the active register bank (see description of the PSW in SFR Definition 7.6). This allows fast context switching when entering subroutines and interrupt service routines. Indirect addressing modes use registers R0 and R1 as index registers. 125 Rev. 1.0 Si106x/108x 8.2.1.2. Bit Addressable Locations In addition to direct access to data memory organized as bytes, the sixteen data memory locations at 0x20 through 0x2F are also accessible as 128 individually addressable bits. Each bit has a bit address from 0x00 to 0x7F. Bit 0 of the byte at 0x20 has bit address 0x00 while bit7 of the byte at 0x20 has bit address 0x07. Bit 7 of the byte at 0x2F has bit address 0x7F. A bit access is distinguished from a full byte access by the type of instruction used (bit source or destination operands as opposed to a byte source or destination). The MCS-51TM assembly language allows an alternate notation for bit addressing of the form XX.B where XX is the byte address and B is the bit position within the byte. For example, the instruction: MOV C, 22.3h moves the Boolean value at 0x13 (bit 3 of the byte at location 0x22) into the Carry flag. 8.2.1.3. Stack A programmer's stack can be located anywhere in the 256-byte data memory. The stack area is designated using the Stack Pointer (SP) SFR. The SP will point to the last location used. The next value pushed on the stack is placed at SP+1 and then SP is incremented. A reset initializes the stack pointer to location 0x07. Therefore, the first value pushed on the stack is placed at location 0x08, which is also the first register (R0) of register bank 1. Thus, if more than one register bank is to be used, the SP should be initialized to a location in the data memory not being used for data storage. The stack depth can extend up to 256 bytes. 8.2.2. External RAM There are 512 bytes (Si108x) or 4096 bytes (Si106x) of on-chip RAM mapped into the external data memory space. All of these address locations may be accessed using the external move instruction (MOVX) and the data pointer (DPTR), or using MOVX indirect addressing mode (such as @R1) in combination with the EMI0CN register. Rev. 1.0 126 Si106x/108x 9. On-Chip XRAM The Si106x/108x MCUs include on-chip RAM mapped into the external data memory space (XRAM). The external memory space may be accessed using the external move instruction (MOVX) with the target address specified in either the data pointer (DPTR), or with the target address low byte in R0 or R1 and the target address high byte in the External Memory Interface Control Register (EMI0CN, shown in SFR Definition 9.1). When using the MOVX instruction to access on-chip RAM, no additional initialization is required and the MOVX instruction execution time is as specified in the CIP-51 chapter. Important Note: MOVX write operations can be configured to target flash memory, instead of XRAM. See Section "12. Flash Memory" on page 149 for more details. The MOVX instruction accesses XRAM by default. 9.1. Accessing XRAM The XRAM memory space is accessed using the MOVX instruction. The MOVX instruction has two forms, both of which use an indirect addressing method. The first method uses the Data Pointer, DPTR, a 16-bit register which contains the effective address of the XRAM location to be read from or written to. The second method uses R0 or R1 in combination with the EMI0CN register to generate the effective XRAM address. Examples of both of these methods are given below. 9.1.1. 16-Bit MOVX Example The 16-bit form of the MOVX instruction accesses the memory location pointed to by the contents of the DPTR register. The following series of instructions reads the value of the byte at address 0x1234 into the accumulator A: MOV MOVX DPTR, #1234h A, @DPTR ; load DPTR with 16-bit address to read (0x1234) ; load contents of 0x1234 into accumulator A The above example uses the 16-bit immediate MOV instruction to set the contents of DPTR. Alternately, the DPTR can be accessed through the SFR registers DPH, which contains the upper 8-bits of DPTR, and DPL, which contains the lower 8-bits of DPTR. 9.1.2. 8-Bit MOVX Example The 8-bit form of the MOVX instruction uses the contents of the EMI0CN SFR to determine the upper 8-bits of the effective address to be accessed and the contents of R0 or R1 to determine the lower 8-bits of the effective address to be accessed. The following series of instructions read the contents of the byte at address 0x1234 into the accumulator A. MOV MOV MOVX EMI0CN, #12h R0, #34h a, @R0 ; load high byte of address into EMI0CN ; load low byte of address into R0 (or R1) ; load contents of 0x1234 into accumulator A Rev. 1.0 127 Si106x/108x 9.2. Special Function Registers The special function register used for configuring XRAM access is EMI0CN. SFR Definition 9.1. EMI0CN: External Memory Interface Control Bit 7 6 5 4 3 2 1 0 PGSEL[3:0] Name Type R R R R Reset 0 0 0 0 R/W 0 0 0 0 SFR Page = 0x0; SFR Address = 0xAA Bit Name Function 7:4 Unused Read = 0000b; Write = Don't Care. 3:0 PGSEL XRAM Page Select. The EMI0CN register provides the high byte of the 16-bit external data memory address when using an 8-bit MOVX command, effectively selecting a 256-byte page of RAM. Since the upper (unused) bits of the register are always zero, EMI0CN determines which page of XRAM is accessed. For Example: If EMI0CN = 0x01, addresses 0x0100 through 0x01FF will be accessed. If EMI0CN = 0x0F, addresses 0x0F00 through 0x0FFF will be accessed. 128 Rev. 1.0 Si106x/108x 10. Special Function Registers The direct-access data memory locations from 0x80 to 0xFF constitute the special function registers (SFRs). The SFRs provide control and data exchange with the Si106x/108x's resources and peripherals. The CIP-51 controller core duplicates the SFRs found in a typical 8051 implementation as well as implementing additional SFRs used to configure and access the sub-systems unique to the Si106x/108x. This allows the addition of new functionality while retaining compatibility with the MCS-51TM instruction set. Table 10.1 and Table 10.2 list the SFRs implemented in the Si106x/108x device family. The SFR registers are accessed anytime the direct addressing mode is used to access memory locations from 0x80 to 0xFF. SFRs with addresses ending in 0x0 or 0x8 (e.g. P0, TCON, SCON0, IE, etc.) are bitaddressable as well as byte-addressable. All other SFRs are byte-addressable only. Unoccupied addresses in the SFR space are reserved for future use. Accessing these areas will have an indeterminate effect and should be avoided. Refer to the corresponding pages of the data sheet, as indicated in Table 10.3, for a detailed description of each register. Table 10.1. Special Function Register (SFR) Memory Map (Page 0x0) F8 F0 E8 E0 D8 D0 C8 C0 B8 B0 A8 A0 98 90 88 80 SPI0CN PCA0L PCA0H PCA0CPL0 PCA0CPH0 B P0MDIN P1MDIN P2MDIN SMB0ADR ADC0CN PCA0CPL1 PCA0CPH1 PCA0CPL2 PCA0CPH2 ACC XBR0 XBR1 XBR2 IT01CF PCA0CN PCA0MD PCA0CPM0 PCA0CPM1 PCA0CPM2 PSW REF0CN PCA0CPL5 PCA0CPH5 P0SKIP TMR2CN REG0CN TMR2RLL TMR2RLH TMR2L SMB0CN SMB0CF SMB0DAT ADC0GTL ADC0GTH IP ADC0AC ADC0MX ADC0CF SPI1CN OSCXCN OSCICN OSCICL IE CLKSEL EMI0CN Reserved RTC0ADR P2 SPI0CFG SPI0CKR SPI0DAT P0MDOUT SCON0 SBUF0 CPT1CN CPT0CN CPT1MD P1 TMR3CN TMR3RLL TMR3RLH TMR3L TCON TMOD TL0 TL1 TH0 P0 SP DPL DPH SPI1CFG 0(8) 1(9) 2(A) 3(B) 4(C) (bit addressable) Rev. 1.0 PCA0CPL4 SMB0ADM PCA0CPL3 PCA0CPM3 P1SKIP TMR2H ADC0LTL ADC0L PMU0CF RTC0DAT P1MDOUT CPT0MD TMR3H TH1 SPI1CKR 5(D) PCA0CPH4 VDM0CN EIP1 EIP2 PCA0CPH3 RSTSRC EIE1 EIE2 PCA0CPM4 PCA0PWM P2SKIP P0MAT PCA0CPM5 P1MAT ADC0LTH P0MASK ADC0H P1MASK FLSCL FLKEY RTC0KEY Reserved P2MDOUT SFRPAGE CPT1MX CPT0MX DC0CF DC0CN CKCON PSCTL SPI1DAT PCON 6(E) 7(F) 129 Si106x/108x 10.1. SFR Paging To accommodate more than 128 SFRs in the 0x80 to 0xFF address space, SFR paging has been implemented. By default, all SFR accesses target SFR Page 0x0 to allow access to the registers listed in Table 10.1. During device initialization, some SFRs located on SFR Page 0xF may need to be accessed. Table 10.2 lists the SFRs accessible from SFR Page 0x0F. Some SFRs are accessible from both pages, including the SFRPAGE register. SFRs accessible only from Page 0xF are in bold. The following procedure should be used when accessing SFRs from Page 0xF: 1. Save the current interrupt state (EA_save = EA). 2. Disable Interrupts (EA = 0). 3. Set SFRPAGE = 0xF. 4. Access the SFRs located on SFR Page 0xF. 5. Set SFRPAGE = 0x0. 6. Restore interrupt state (EA = EA_save). Table 10.2. Special Function Register (SFR) Memory Map (Page 0xF) F8 F0 E8 E0 D8 D0 C8 C0 B8 B0 A8 A0 98 90 88 80 B EIP1 EIP2 ACC EIE1 EIE2 P2DRV SFRPAGE PSW ADC0PWR IE P2 CLKSEL P1 CRC0DAT P0DRV P0 SP 0(8) 1(9) (bit addressable) 130 ADC0TK CRC0CN CRC0IN DPL 2(A) DPH 3(B) P1DRV CRC0FLIP 4(C) Rev. 1.0 TOFFL 5(D) CRC0AUTO CRC0CNT TOFFH 6(E) PCON 7(F) Si106x/108x SFR Definition 10.1. SFRPage: SFR Page Bit 7 6 5 4 3 Name SFRPAGE[7:0] Type R/W Reset 0 0 0 0 SFR Page = All Pages; SFR Address = 0xA7 Bit Name 0 2 1 0 0 0 0 Function 7:0 SFRPAGE[7:0] SFR Page. Specifies the SFR Page used when reading, writing, or modifying special function registers. Table 10.3. Special Function Registers SFRs are listed in alphabetical order. All undefined SFR locations are reserved Register Address SFR Page Description ACC 0xE0 All Accumulator 120 ADC0AC 0xBA 0x0 ADC0 Accumulator Configuration 88 ADC0CF 0xBC 0x0 ADC0 Configuration 87 ADC0CN 0xE8 0x0 ADC0 Control 86 ADC0GTH 0xC4 0x0 ADC0 Greater-Than Compare High 92 ADC0GTL 0xC3 0x0 ADC0 Greater-Than Compare Low 92 ADC0H 0xBE 0x0 ADC0 High 91 ADC0L 0xBD 0x0 ADC0 Low 91 ADC0LTH 0xC6 0x0 ADC0 Less-Than Compare Word High 93 ADC0LTL 0xC5 0x0 ADC0 Less-Than Compare Word Low 93 ADC0MX 0xBB 0x0 AMUX0 Channel Select 96 ADC0PWR 0xBA 0xF ADC0 Burst Mode Power-Up Time 89 ADC0TK 0xBD 0xF ADC0 Tracking Control 90 B 0xF0 All B Register 120 CKCON 0x8E 0x0 Clock Control 312 CLKSEL 0xA9 All Clock Select 197 CPT0CN 0x9B 0x0 Comparator0 Control 107 CPT0MD 0x9D 0x0 Comparator0 Mode Selection 107 CPT0MX 0x9F 0x0 Comparator0 Mux Selection 111 CPT1CN 0x9A 0x0 Comparator1 Control 108 CPT1MD 0x9C 0x0 Comparator1 Mode Selection 109 CPT1MX 0x9E 0x0 Comparator1 Mux Selection 112 CRC0AUTO 0x96 0xF CRC0 Automatic Control 173 Rev. 1.0 Page 131 Si106x/108x Table 10.3. Special Function Registers (Continued) SFRs are listed in alphabetical order. All undefined SFR locations are reserved Register Address SFR Page Description Page CRC0CN 0x92 0xF CRC0 Control 171 CRC0CNT 0x97 0xF CRC0 Automatic Flash Sector Count 173 CRC0DAT 0x91 0xF CRC0 Data 172 CRC0FLIP 0x95 0xF CRC0 Flip 174 CRC0IN 0x93 0xF CRC0 Input 172 DC0CF 0x96 0x0 DC0 (DC-DC Converter) Configuration 182 DC0CN 0x97 0x0 DC0 (DC-DC Converter) Control 181 DPH 0x83 All Data Pointer High 119 DPL 0x82 All Data Pointer Low 119 EIE1 0xE6 All Extended Interrupt Enable 1 143 EIE2 0xE7 All Extended Interrupt Enable 2 145 EIP1 0xF6 0x0 Extended Interrupt Priority 1 144 EIP2 0xF7 0x0 Extended Interrupt Priority 2 146 EMI0CN 0xAA 0x0 EMIF Control 128 FLKEY 0xB7 0x0 Flash Lock And Key 158 FLSCL 0xB6 0x0 Flash Scale 158 IE 0xA8 All Interrupt Enable 141 IP 0xB8 0x0 Interrupt Priority 142 IT01CF 0xE4 0x0 INT0/INT1 Configuration 148 OSCICL 0xB3 0x0 Internal Oscillator Calibration 198 OSCICN 0xB2 0x0 Internal Oscillator Control 198 OSCXCN 0xB1 0x0 External Oscillator Control 199 P0 0x80 All Port 0 Latch 230 P0DRV 0xA4 0xF Port 0 Drive Strength 232 P0MASK 0xC7 0x0 Port 0 Mask 227 P0MAT 0xD7 0x0 Port 0 Match 227 P0MDIN 0xF1 0x0 Port 0 Input Mode Configuration 231 P0MDOUT 0xA4 0x0 Port 0 Output Mode Configuration 231 P0SKIP 0xD4 0x0 Port 0 Skip 230 P1 0x90 All Port 1 Latch 233 P1DRV 0xA5 0xF Port 1 Drive Strength 235 P1MASK 0xBF 0x0 Port 1 Mask 228 P1MAT 0xCF 0x0 Port 1 Match 228 P1MDIN 0xF2 0x0 Port 1 Input Mode Configuration 234 P1MDOUT 0xA5 0x0 Port 1 Output Mode Configuration 234 P1SKIP 0xD5 0x0 Port 1 Skip 233 P2 0xA0 All Port 2 Latch 235 132 Rev. 1.0 Si106x/108x Table 10.3. Special Function Registers (Continued) SFRs are listed in alphabetical order. All undefined SFR locations are reserved Register Address SFR Page Description P2DRV 0xA6 0xF Port 2 Drive Strength 237 P2MDIN 0xF3 0x0 Port 2 Input Mode Configuration 236 P2MDOUT 0xA6 0x0 Port 2 Output Mode Configuration 237 P2SKIP 0xD6 0x0 Port 2 Skip 236 PCA0CN 0xD8 0x0 PCA0 Control 346 PCA0CPH0 0xFC 0x0 PCA0 Capture 0 High 351 PCA0CPH1 0xEA 0x0 PCA0 Capture 1 High 351 PCA0CPH2 0xEC 0x0 PCA0 Capture 2 High 351 PCA0CPH3 0xEE 0x0 PCA0 Capture 3 High 351 PCA0CPH4 0xFE 0x0 PCA0 Capture 4 High 351 PCA0CPH5 0xD3 0x0 PCA0 Capture 5 High 351 PCA0CPL0 0xFB 0x0 PCA0 Capture 0 Low 351 PCA0CPL1 0xE9 0x0 PCA0 Capture 1 Low 351 PCA0CPL2 0xEB 0x0 PCA0 Capture 2 Low 351 PCA0CPL3 0xED 0x0 PCA0 Capture 3 Low 351 PCA0CPL4 0xFD 0x0 PCA0 Capture 4 Low 351 PCA0CPL5 0xD2 0x0 PCA0 Capture 5 Low 351 PCA0CPM0 0xDA 0x0 PCA0 Module 0 Mode Register 349 PCA0CPM1 0xDB 0x0 PCA0 Module 1 Mode Register 349 PCA0CPM2 0xDC 0x0 PCA0 Module 2 Mode Register 349 PCA0CPM3 0xDD 0x0 PCA0 Module 3 Mode Register 349 PCA0CPM4 0xDE 0x0 PCA0 Module 4 Mode Register 349 PCA0CPM5 0xCE 0x0 PCA0 Module 5 Mode Register 349 PCA0H 0xFA 0x0 PCA0 Counter High 350 PCA0L 0xF9 0x0 PCA0 Counter Low 350 PCA0MD 0xD9 0x0 PCA0 Mode 347 PCA0PWM 0xDF 0x0 PCA0 PWM Configuration 348 PCON 0x87 0x0 Power Control 166 PMU0CF 0xB5 0x0 PMU0 Configuration 165 PSCTL 0x8F 0x0 Program Store R/W Control 157 PSW 0xD0 All Program Status Word 121 REF0CN 0xD1 0x0 Voltage Reference Control 102 REG0CN 0xC9 0x0 Voltage Regulator (VREG0) Control 184 RSTSRC 0xEF 0x0 Reset Source Configuration/Status 191 RTC0ADR 0xAC 0x0 RTC0 Address 205 RTC0DAT 0xAD 0x0 RTC0 Data 206 RTC0KEY 0xAE 0x0 RTC0 Key 204 SBUF0 0x99 0x0 UART0 Data Buffer 296 Rev. 1.0 Page 133 Si106x/108x Table 10.3. Special Function Registers (Continued) SFRs are listed in alphabetical order. All undefined SFR locations are reserved Register Address SFR Page Description Page SCON0 0x98 0x0 UART0 Control 295 SFRPAGE 0xA7 All SFR Page 131 SMB0ADM 0xF5 0x0 SMBus Slave Address Mask 278 SMB0ADR 0xF4 0x0 SMBus Slave Address 278 SMB0CF 0xC1 0x0 SMBus0 Configuration 273 SMB0CN 0xC0 0x0 SMBus0 Control 275 SMB0DAT 0xC2 0x0 SMBus0 Data 281 SP 0x81 All Stack Pointer 120 SPI0CFG 0xA1 0x0 SPI0 Configuration 305 SPI0CKR 0xA2 0x0 SPI0 Clock Rate Control 307 SPI0CN 0xF8 0x0 SPI0 Control 306 SPI0DAT 0xA3 0x0 SPI0 Data 307 SPI1CFG 0x84 0x0 SPI1 Configuration 305 SPI1CKR 0x85 0x0 SPI1 Clock Rate Control 307 SPI1CN 0xB0 0x0 SPI1 Control 306 SPI1DAT 0x86 0x0 SPI1 Data 307 TCON 0x88 0x0 Timer/Counter Control 317 TH0 0x8C 0x0 Timer/Counter 0 High 320 TH1 0x8D 0x0 Timer/Counter 1 High 320 TL0 0x8A 0x0 Timer/Counter 0 Low 319 TL1 0x8B 0x0 Timer/Counter 1 Low 319 TMOD 0x89 0x0 Timer/Counter Mode 318 TMR2CN 0xC8 0x0 Timer/Counter 2 Control 324 TMR2H 0xCD 0x0 Timer/Counter 2 High 326 TMR2L 0xCC 0x0 Timer/Counter 2 Low 326 TMR2RLH 0xCB 0x0 Timer/Counter 2 Reload High 325 TMR2RLL 0xCA 0x0 Timer/Counter 2 Reload Low 325 TMR3CN 0x91 0x0 Timer/Counter 3 Control 330 TMR3H 0x95 0x0 Timer/Counter 3 High 332 TMR3L 0x94 0x0 Timer/Counter 3 Low 332 TMR3RLH 0x93 0x0 Timer/Counter 3 Reload High 331 TMR3RLL 0x92 0x0 Timer/Counter 3 Reload Low 331 TOFFH 0x86 0xF Temperature Offset High 99 TOFFL 0x85 0xF Temperature Offset Low 99 VDM0CN 0xFF 0x0 VDD Monitor Control 189 XBR0 0xE1 0x0 Port I/O Crossbar Control 0 224 XBR1 0xE2 0x0 Port I/O Crossbar Control 1 225 XBR2 0xE3 0x0 Port I/O Crossbar Control 2 226 134 Rev. 1.0 Si106x/108x Devices in the Si106x device family share the same SFR address locations for most registers. This allows the si1060_defs.h and the si1080_defs.h header files to be used interchangeably in applications that target devices in the Si106x and Si108x family. It also allows code developed on one device to be executed on any other device in the product family without modification. There are few minor differences between the si1060_defs.h and the si1080_defs.h files. When writing software that targets multiple devices in the Si106x and Si108x family, the si1060_defs.h header file is recommended because it does not contain definitions for the "plus" registers which are only found on the Si106x devices. When using this header file, a compiler error will be generated if any of the "plus" registers are used in the software. Table 10.4 highlights the registers that are not identical in all devices in the Si106x and Si108x product family. Table 10.4. Select Registers with Varying Function Register Name Description of difference Registers Found only in C8051F930_defs.h EMI0CF EMI0TC Only apply to 32-pin devices. EMIF is not available on 24-pin devices. P2SKIP P2MDIN Only apply to 32-pin devices. On 24-pin devices, P2 does not have Crossbar or analog functionality. Registers Found only in C8051F912_defs.h PMU0MD DC0MD IREF0CF Only apply to the `F912 and `F902. Not available on the `F911 or `F901. Registers with bit differences PCA0MD On `F912 and `F902 devices, SmaRTClock/8 may be selected as the PCA timebase. VDM0CN On `F912 and `F902 devices, configuration bits for the VBAT supply monitor can be used to enable a VBAT low "early warning" interrupt. DC0CF On `F912 and `F902 devices, bit 7 enables the low power mode for the dcdc converter. This low power mode is a "plus" feature. ADC0AC On `F912 and `F902 devices, bit 7 enables the 12-bit mode for ADC0. The 12-bit mode is a "plus" feature. Rev. 1.0 135 Si106x/108x Table 10.4. Select Registers with Varying Function (Continued) Register Name ADC0PWR Description of difference On `F912 and `F902 devices, bit 7 enables the low power mode for ADC0. This low power mode is a "plus" feature. Indirect SmaRTClock registers with bit differences 136 RTC0XCN On `F912 and `F902 devices, bit 3 enables the SmaRTClock's internal low frequency oscillator. The LFO is a "plus" feature. RTC0PIN On C8051F930/31/20/21 devices, this register is write only. It is R/W on all other devices. Rev. 1.0 Si106x/108x 11. Interrupt Handler The Si106x/108x microcontroller family includes an extended interrupt system supporting multiple interrupt sources and two priority levels. The allocation of interrupt sources between on-chip peripherals and external input pins varies according to the specific version of the device. Refer to Table 11.1, "Interrupt Summary," on page 139 for a detailed listing of all interrupt sources supported by the device. Refer to the data sheet section associated with a particular on-chip peripheral for information regarding valid interrupt conditions for the peripheral and the behavior of its interrupt-pending flag(s). Each interrupt source has one or more associated interrupt-pending flag(s) located in an SFR or an indirect register. When a peripheral or external source meets a valid interrupt condition, the associated interrupt-pending flag is set to logic 1. If both global interrupts and the specific interrupt source is enabled, a CPU interrupt request is generated when the interrupt-pending flag is set. As soon as execution of the current instruction is complete, the CPU generates an LCALL to a predetermined address to begin execution of an interrupt service routine (ISR). Each ISR must end with an RETI instruction, which returns program execution to the next instruction that would have been executed if the interrupt request had not occurred. If interrupts are not enabled, the interrupt-pending flag is ignored by the hardware and program execution continues as normal. (The interrupt-pending flag is set to logic 1 regardless of the interrupt's enable/disable state.) Some interrupt-pending flags are automatically cleared by hardware when the CPU vectors to the ISR. However, most are not cleared by the hardware and must be cleared by software before returning from the ISR. If an interrupt-pending flag remains set after the CPU completes the return-from-interrupt (RETI) instruction, a new interrupt request will be generated immediately and the CPU will re-enter the ISR after the completion of the next instruction. 11.1. Enabling Interrupt Sources Each interrupt source can be individually enabled or disabled through the use of an associated interrupt enable bit in the Interrupt Enable and Extended Interrupt Enable SFRs. However, interrupts must first be globally enabled by setting the EA bit (IE.7) to logic 1 before the individual interrupt enables are recognized. Setting the EA bit to logic 0 disables all interrupt sources regardless of the individual interruptenable settings. Note that interrupts which occur when the EA bit is set to logic 0 will be held in a pending state, and will not be serviced until the EA bit is set back to logic 1. 11.2. MCU Interrupt Sources and Vectors The CPU services interrupts by generating an LCALL to a predetermined address (the interrupt vector address) to begin execution of an interrupt service routine (ISR). The interrupt vector addresses associated with each interrupt source are listed in Table 11.1 on page 139. Software should ensure that the interrupt vector for each enabled interrupt source contains a valid interrupt service routine. Software can simulate an interrupt by setting any interrupt-pending flag to logic 1. If interrupts are enabled for the flag, an interrupt request will be generated and the CPU will vector to the ISR address associated with the interrupt-pending flag. Rev. 1.0 137 Si106x/108x 11.3. Interrupt Priorities Each interrupt source can be individually programmed to one of two priority levels: low or high. A low priority interrupt service routine can be preempted by a high priority interrupt. A high priority interrupt cannot be preempted. If a high priority interrupt preempts a low priority interrupt, the low priority interrupt will finish execution after the high priority interrupt completes. Each interrupt has an associated interrupt priority bit in in the Interrupt Priority and Extended Interrupt Priority registers used to configure its priority level. Low priority is the default. If two interrupts are recognized simultaneously, the interrupt with the higher priority is serviced first. If both interrupts have the same priority level, a fixed priority order is used to arbitrate. See Table 11.1 on page 139 to determine the fixed priority order used to arbitrate between simultaneously recognized interrupts. 11.4. Interrupt Latency Interrupt response time depends on the state of the CPU when the interrupt occurs. Pending interrupts are sampled and priority decoded each system clock cycle. Therefore, the fastest possible response time is 7 system clock cycles: 1 clock cycle to detect the interrupt, 1 clock cycle to execute a single instruction, and 5 clock cycles to complete the LCALL to the ISR. If an interrupt is pending when a RETI is executed, a single instruction is executed before an LCALL is made to service the pending interrupt. Therefore, the maximum response time for an interrupt (when no other interrupt is currently being serviced or the new interrupt is of greater priority) occurs when the CPU is performing an RETI instruction followed by a DIV as the next instruction. In this case, the response time is 19 system clock cycles: 1 clock cycle to detect the interrupt, 5 clock cycles to execute the RETI, 8 clock cycles to complete the DIV instruction and 5 clock cycles to execute the LCALL to the ISR. If the CPU is executing an ISR for an interrupt with equal or higher priority, the new interrupt will not be serviced until the current ISR completes, including the RETI and following instruction. 138 Rev. 1.0 Si106x/108x Pending Flag Priority Order Bit addressable? 0x0000 Top None N/A N/A Always Enabled Always Highest External Interrupt 0 (INT0) 0x0003 0 IE0 (TCON.1) Y Y EX0 (IE.0) PX0 (IP.0) Timer 0 Overflow 0x000B 1 TF0 (TCON.5) Y Y ET0 (IE.1) PT0 (IP.1) External Interrupt 1 (INT1) 0x0013 2 IE1 (TCON.3) Y Y EX1 (IE.2) PX1 (IP.2) Timer 1 Overflow 0x001B 3 TF1 (TCON.7) Y Y ET1 (IE.3) PT1 (IP.3) UART0 0x0023 4 RI0 (SCON0.0) TI0 (SCON0.1) Y N ES0 (IE.4) PS0 (IP.4) Timer 2 Overflow 0x002B 5 TF2H (TMR2CN.7) TF2L (TMR2CN.6) Y N ET2 (IE.5) PT2 (IP.5) SPI0 0x0033 6 SPIF (SPI0CN.7) Y WCOL (SPI0CN.6) MODF (SPI0CN.5) RXOVRN (SPI0CN.4) N ESPI0 (IE.6) PSPI0 (IP.6) SMB0 0x003B 7 SI (SMB0CN.0) Y N ESMB0 (EIE1.0) PSMB0 (EIP1.0) SmaRTClock Alarm 0x0043 8 ALRM (RTC0CN.2)* N N EARTC0 (EIE1.1) PARTC0 (EIP1.1) ADC0 Window Comparator 0x004B 9 AD0WINT (ADC0CN.3) Y N EWADC0 (EIE1.2) PWADC0 (EIP1.2) ADC0 End of Conversion 0x0053 10 AD0INT (ADC0STA.5) Y N EADC0 (EIE1.3) PADC0 (EIP1.3) Programmable Counter Array 0x005B 11 CF (PCA0CN.7) CCFn (PCA0CN.n) Y N EPCA0 (EIE1.4) PPCA0 (EIP1.4) Comparator0 0x0063 12 CP0FIF (CPT0CN.4) CP0RIF (CPT0CN.5) N N ECP0 (EIE1.5) PCP0 (EIP1.5) Comparator1 0x006B 13 CP1FIF (CPT1CN.4) CP1RIF (CPT1CN.5) N N ECP1 (EIE1.6) PCP1 (EIP1.6) Timer 3 Overflow 0x0073 14 TF3H (TMR3CN.7) TF3L (TMR3CN.6) N N ET3 (EIE1.7) PT3 (EIP1.7) VDD_MCU Supply Monitor Early Warning 0x007B 15 VDDOK (VDM0CN.5)1 EWARN (EIE2.0) PWARN (EIP2.0) Port Match 0x0083 16 None EMAT (EIE2.1) PMAT (EIP2.1) Interrupt Source Reset Rev. 1.0 Cleared by HW? Interrupt Vector Table 11.1. Interrupt Summary Enable Flag Priority Control 139 Si106x/108x 0x0093 Cleared by HW? Radio Serial Interface (SPI1) Priority Control N N ERTC0F (EIE2.2) PFRTC0F (EIP2.2) N ESPI1 (EIE2.3) PSPI1 (EIP2.3) Pending Flag Priority Order SmaRTClock Oscillator Fail Enable Flag Interrupt Vector Interrupt Source Bit addressable? Table 11.1. Interrupt Summary (Continued) 0x008B 17 OSCFAIL (RTC0CN.5)2 18 SPIF (SPI1CN.7) N WCOL (SPI1CN.6) MODF (SPI1CN.5) RXOVRN (SPI1CN.4) Notes: 1. Indicates a read-only interrupt pending flag. The interrupt enable may be used to prevent software from vectoring to the associated interrupt service routine. 2. Indicates a register located in an indirect memory space. 11.5. Interrupt Register Descriptions The SFRs used to enable the interrupt sources and set their priority level are described in the following register descriptions. Refer to the data sheet section associated with a particular on-chip peripheral for information regarding valid interrupt conditions for the peripheral and the behavior of its interrupt-pending flag(s). 140 Rev. 1.0 Si106x/108x SFR Definition 11.1. IE: Interrupt Enable Bit 7 6 5 4 3 2 1 0 Name EA ESPI0 ET2 ES0 ET1 EX1 ET0 EX0 Type R/W R/W R/W R/W R/W R/W R/W R/W Reset 0 0 0 0 0 0 0 0 SFR Page = All Pages; SFR Address = 0xA8; Bit-Addressable Bit Name Function 7 EA 6 ESPI0 5 ET2 Enable Timer 2 Interrupt. This bit sets the masking of the Timer 2 interrupt. 0: Disable Timer 2 interrupt. 1: Enable interrupt requests generated by the TF2L or TF2H flags. 4 ES0 Enable UART0 Interrupt. This bit sets the masking of the UART0 interrupt. 0: Disable UART0 interrupt. 1: Enable UART0 interrupt. 3 ET1 Enable Timer 1 Interrupt. This bit sets the masking of the Timer 1 interrupt. 0: Disable all Timer 1 interrupt. 1: Enable interrupt requests generated by the TF1 flag. 2 EX1 Enable External Interrupt 1. This bit sets the masking of External Interrupt 1. 0: Disable external interrupt 1. 1: Enable interrupt requests generated by the INT1 input. 1 ET0 Enable Timer 0 Interrupt. This bit sets the masking of the Timer 0 interrupt. 0: Disable all Timer 0 interrupt. 1: Enable interrupt requests generated by the TF0 flag. 0 EX0 Enable External Interrupt 0. This bit sets the masking of External Interrupt 0. 0: Disable external interrupt 0. 1: Enable interrupt requests generated by the INT0 input. Enable All Interrupts. Globally enables/disables all interrupts. It overrides individual interrupt mask settings. 0: Disable all interrupt sources. 1: Enable each interrupt according to its individual mask setting. Enable Serial Peripheral Interface (SPI0) Interrupt. This bit sets the masking of the SPI0 interrupts. 0: Disable all SPI0 interrupts. 1: Enable interrupt requests generated by SPI0. Rev. 1.0 141 Si106x/108x SFR Definition 11.2. IP: Interrupt Priority Bit 7 Name 6 5 4 3 2 1 0 PSPI0 PT2 PS0 PT1 PX1 PT0 PX0 Type R R/W R/W R/W R/W R/W R/W R/W Reset 1 0 0 0 0 0 0 0 SFR Page = 0x0; SFR Address = 0xB8; Bit-Addressable Bit Name Function 7 6 Unused PSPI0 5 PT2 Timer 2 Interrupt Priority Control. This bit sets the priority of the Timer 2 interrupt. 0: Timer 2 interrupt set to low priority level. 1: Timer 2 interrupt set to high priority level. 4 PS0 UART0 Interrupt Priority Control. This bit sets the priority of the UART0 interrupt. 0: UART0 interrupt set to low priority level. 1: UART0 interrupt set to high priority level. 3 PT1 Timer 1 Interrupt Priority Control. This bit sets the priority of the Timer 1 interrupt. 0: Timer 1 interrupt set to low priority level. 1: Timer 1 interrupt set to high priority level. 2 PX1 External Interrupt 1 Priority Control. This bit sets the priority of the External Interrupt 1 interrupt. 0: External Interrupt 1 set to low priority level. 1: External Interrupt 1 set to high priority level. 1 PT0 Timer 0 Interrupt Priority Control. This bit sets the priority of the Timer 0 interrupt. 0: Timer 0 interrupt set to low priority level. 1: Timer 0 interrupt set to high priority level. 0 PX0 External Interrupt 0 Priority Control. This bit sets the priority of the External Interrupt 0 interrupt. 0: External Interrupt 0 set to low priority level. 1: External Interrupt 0 set to high priority level. 142 Read = 1b, Write = don't care. Serial Peripheral Interface (SPI0) Interrupt Priority Control. This bit sets the priority of the SPI0 interrupt. 0: SPI0 interrupt set to low priority level. 1: SPI0 interrupt set to high priority level. Rev. 1.0 Si106x/108x SFR Definition 11.3. EIE1: Extended Interrupt Enable 1 Bit 7 6 5 4 3 2 1 0 Name ET3 ECP1 ECP0 EPCA0 EADC0 EWADC0 ERTC0A ESMB0 Type R/W R/W R/W R/W R/W R/W R/W R/W Reset 0 0 0 0 0 0 0 0 SFR Page = All Pages; SFR Address = 0xE6 Bit Name Function 7 ET3 6 ECP1 Enable Comparator1 (CP1) Interrupt. This bit sets the masking of the CP1 interrupt. 0: Disable CP1 interrupts. 1: Enable interrupt requests generated by the CP1RIF or CP1FIF flags. 5 ECP0 Enable Comparator0 (CP0) Interrupt. This bit sets the masking of the CP0 interrupt. 0: Disable CP0 interrupts. 1: Enable interrupt requests generated by the CP0RIF or CP0FIF flags. 4 EPCA0 Enable Programmable Counter Array (PCA0) Interrupt. This bit sets the masking of the PCA0 interrupts. 0: Disable all PCA0 interrupts. 1: Enable interrupt requests generated by PCA0. 3 EADC0 Enable ADC0 Conversion Complete Interrupt. This bit sets the masking of the ADC0 Conversion Complete interrupt. 0: Disable ADC0 Conversion Complete interrupt. 1: Enable interrupt requests generated by the AD0INT flag. Enable Timer 3 Interrupt. This bit sets the masking of the Timer 3 interrupt. 0: Disable Timer 3 interrupts. 1: Enable interrupt requests generated by the TF3L or TF3H flags. 2 EWADC0 Enable Window Comparison ADC0 Interrupt. This bit sets the masking of ADC0 Window Comparison interrupt. 0: Disable ADC0 Window Comparison interrupt. 1: Enable interrupt requests generated by ADC0 Window Compare flag (AD0WINT). 1 ERTC0A Enable SmaRTClock Alarm Interrupts. This bit sets the masking of the SmaRTClock Alarm interrupt. 0: Disable SmaRTClock Alarm interrupts. 1: Enable interrupt requests generated by a SmaRTClock Alarm. 0 ESMB0 Enable SMBus (SMB0) Interrupt. This bit sets the masking of the SMB0 interrupt. 0: Disable all SMB0 interrupts. 1: Enable interrupt requests generated by SMB0. Rev. 1.0 143 Si106x/108x SFR Definition 11.4. EIP1: Extended Interrupt Priority 1 Bit 7 6 5 4 3 2 1 0 Name PT3 PCP1 PCP0 PPCA0 PADC0 PWADC0 PRTC0A PSMB0 Type R/W R/W R/W R/W R/W R/W R/W R/W Reset 0 0 0 0 0 0 0 0 SFR Page = All Pages; SFR Address = 0xF6 Bit Name Function 7 PT3 Timer 3 Interrupt Priority Control. This bit sets the priority of the Timer 3 interrupt. 0: Timer 3 interrupts set to low priority level. 1: Timer 3 interrupts set to high priority level. 6 PCP1 Comparator1 (CP1) Interrupt Priority Control. This bit sets the priority of the CP1 interrupt. 0: CP1 interrupt set to low priority level. 1: CP1 interrupt set to high priority level. 5 PCP0 Comparator0 (CP0) Interrupt Priority Control. This bit sets the priority of the CP0 interrupt. 0: CP0 interrupt set to low priority level. 1: CP0 interrupt set to high priority level. 4 PPCA0 Programmable Counter Array (PCA0) Interrupt Priority Control. This bit sets the priority of the PCA0 interrupt. 0: PCA0 interrupt set to low priority level. 1: PCA0 interrupt set to high priority level. 3 PADC0 ADC0 Conversion Complete Interrupt Priority Control. This bit sets the priority of the ADC0 Conversion Complete interrupt. 0: ADC0 Conversion Complete interrupt set to low priority level. 1: ADC0 Conversion Complete interrupt set to high priority level. 2 PWADC0 ADC0 Window Comparator Interrupt Priority Control. This bit sets the priority of the ADC0 Window interrupt. 0: ADC0 Window interrupt set to low priority level. 1: ADC0 Window interrupt set to high priority level. 1 PRTC0A SmaRTClock Alarm Interrupt Priority Control. This bit sets the priority of the SmaRTClock Alarm interrupt. 0: SmaRTClock Alarm interrupt set to low priority level. 1: SmaRTClock Alarm interrupt set to high priority level. 0 PSMB0 144 SMBus (SMB0) Interrupt Priority Control. This bit sets the priority of the SMB0 interrupt. 0: SMB0 interrupt set to low priority level. 1: SMB0 interrupt set to high priority level. Rev. 1.0 Si106x/108x SFR Definition 11.5. EIE2: Extended Interrupt Enable 2 Bit 7 6 5 4 Name 3 2 1 0 ESPI1 ERTC0F EMAT EWARN Type R/W R/W R/W R/W R/W R/W R/W R/W Reset 0 0 0 0 0 0 0 0 SFR Page = All Pages;SFR Address = 0xE7 Bit Name 7:4 3 2 1 0 Function Unused Read = 0000b. Write = Don't care. ESPI1 Enable Serial Peripheral Interface (SPI1) Interrupt. This bit sets the masking of the SPI1 interrupts. 0: Disable all SPI1 interrupts. 1: Enable interrupt requests generated by SPI1. ERTC0F Enable SmaRTClock Oscillator Fail Interrupt. This bit sets the masking of the SmaRTClock Alarm interrupt. 0: Disable SmaRTClock Alarm interrupts. 1: Enable interrupt requests generated by SmaRTClock Alarm. EMAT Enable Port Match Interrupts. This bit sets the masking of the Port Match Event interrupt. 0: Disable all Port Match interrupts. 1: Enable interrupt requests generated by a Port Match. EWARN Enable VDD_MCU Supply Monitor Early Warning Interrupt. This bit sets the masking of the VDD_MCU Supply Monitor Early Warning interrupt. 0: Disable the VDD_MCU Supply Monitor Early Warning interrupt. 1: Enable interrupt requests generated by VDD_MCU Supply Monitor. Rev. 1.0 145 Si106x/108x SFR Definition 11.6. EIP2: Extended Interrupt Priority 2 Bit 7 6 5 4 Name 3 2 1 0 PSPI1 PRTC0F PMAT PWARN Type R R R R R/W R/W R/W R/W Reset 0 0 0 0 0 0 0 0 SFR Page = All Pages; SFR Address = 0xF7 Bit Name Function 7:4 Unused Read = 0000b. Write = Don't care. 3 PSPI1 Serial Peripheral Interface (SPI1) Interrupt Priority Control. This bit sets the priority of the SPI1 interrupt. 0: SP1 interrupt set to low priority level. 1: SPI1 interrupt set to high priority level. 2 1 0 146 PRTC0F SmaRTClock Oscillator Fail Interrupt Priority Control. This bit sets the priority of the SmaRTClock Alarm interrupt. 0: SmaRTClock Alarm interrupt set to low priority level. 1: SmaRTClock Alarm interrupt set to high priority level. PMAT Port Match Interrupt Priority Control. This bit sets the priority of the Port Match Event interrupt. 0: Port Match interrupt set to low priority level. 1: Port Match interrupt set to high priority level. PWARN VDD_MCU Supply Monitor Early Warning Interrupt Priority Control. This bit sets the priority of the VDD_MCU Supply Monitor Early Warning interrupt. 0: VDD_MCU Supply Monitor Early Warning interrupt set to low priority level. 1: VDD_MCU Supply Monitor Early Warning interrupt set to high priority level. Rev. 1.0 Si106x/108x 11.6. External Interrupts INT0 and INT1 The INT0 and INT1 external interrupt sources are configurable as active high or low, edge or level sensitive. The IN0PL (INT0 Polarity) and IN1PL (INT1 Polarity) bits in the IT01CF register select active high or active low; the IT0 and IT1 bits in TCON (Section "31.1. Timer 0 and Timer 1" on page 313) select level or edge sensitive. The table below lists the possible configurations. IT0 IN0PL INT0 Interrupt IT1 IN1PL INT1 Interrupt 1 0 Active low, edge sensitive 1 0 Active low, edge sensitive 1 1 Active high, edge sensitive 1 1 Active high, edge sensitive 0 0 Active low, level sensitive 0 0 Active low, level sensitive 0 1 Active high, level sensitive 0 1 Active high, level sensitive INT0 and INT1 are assigned to Port pins as defined in the IT01CF register (see SFR Definition 11.7). Note that INT0 and INT0 Port pin assignments are independent of any Crossbar assignments. INT0 and INT1 will monitor their assigned Port pins without disturbing the peripheral that was assigned the Port pin via the Crossbar. To assign a Port pin only to INT0 and/or INT1, configure the Crossbar to skip the selected pin(s). This is accomplished by setting the associated bit in register XBR0 (see Section "20.3. Priority Crossbar Decoder" on page 221 for complete details on configuring the Crossbar). IE0 (TCON.1) and IE1 (TCON.3) serve as the interrupt-pending flags for the INT0 and INT1 external interrupts, respectively. If an INT0 or INT1 external interrupt is configured as edge-sensitive, the corresponding interrupt-pending flag is automatically cleared by the hardware when the CPU vectors to the ISR. When configured as level sensitive, the interrupt-pending flag remains logic 1 while the input is active as defined by the corresponding polarity bit (IN0PL or IN1PL); the flag remains logic 0 while the input is inactive. The external interrupt source must hold the input active until the interrupt request is recognized. It must then deactivate the interrupt request before execution of the ISR completes or another interrupt request will be generated. Rev. 1.0 147 Si106x/108x SFR Definition 11.7. IT01CF: INT0/INT1 Configuration Bit 7 6 Name IN1PL IN1SL[2:0] IN0PL IN0SL[2:0] Type R/W R/W R/W R/W Reset 0 0 5 0 4 0 3 0 2 0 1 0 0 1 SFR Page = 0x0; SFR Address = 0xE4 Bit Name 7 IN1PL 6:4 3 2:0 148 Function INT1 Polarity. 0: INT1 input is active low. 1: INT1 input is active high. IN1SL[2:0] INT1 Port Pin Selection Bits. These bits select which Port pin is assigned to INT1. Note that this pin assignment is independent of the Crossbar; INT1 will monitor the assigned Port pin without disturbing the peripheral that has been assigned the Port pin via the Crossbar. The Crossbar will not assign the Port pin to a peripheral if it is configured to skip the selected pin. 000: Select P0.0 001: Select P0.1 010: Select P0.2 011: Select P0.3 100: Select P0.4 101: Select P0.5 110: Select P0.6 111: Select P0.7 IN0PL INT0 Polarity. 0: INT0 input is active low. 1: INT0 input is active high. IN0SL[2:0] INT0 Port Pin Selection Bits. These bits select which Port pin is assigned to INT0. Note that this pin assignment is independent of the Crossbar; INT0 will monitor the assigned Port pin without disturbing the peripheral that has been assigned the Port pin via the Crossbar. The Crossbar will not assign the Port pin to a peripheral if it is configured to skip the selected pin. 000: Select P0.0 001: Select P0.1 010: Select P0.2 011: Select P0.3 100: Select P0.4 101: Select P0.5 110: Select P0.6 111: Select P0.7 Rev. 1.0 Si106x/108x 12. Flash Memory On-chip, re-programmable flash memory is included for program code and non-volatile data storage. The flash memory can be programmed in-system through the C2 interface or by software using the MOVX write instruction. Once cleared to logic 0, a flash bit must be erased to set it back to logic 1. Flash bytes would typically be erased (set to 0xFF) before being reprogrammed. The write and erase operations are automatically timed by hardware for proper execution; data polling to determine the end of the write/erase operations is not required. Code execution is stalled during flash write/erase operations. Refer to Table 4.6 for complete flash memory electrical characteristics. 12.1. Programming the Flash Memory The simplest means of programming the flash memory is through the C2 interface using programming tools provided by Silicon Laboratories or a third party vendor. This is the only means for programming a non-initialized device. For details on the C2 commands to program flash memory, see Section "33. Device Specific Behavior" on page 352. The flash memory can be programmed by software using the MOVX write instruction with the address and data byte to be programmed provided as normal operands. Before programming flash memory using MOVX, flash programming operations must be enabled by: (1) setting the PSWE Program Store Write Enable bit (PSCTL.0) to logic 1 (this directs the MOVX writes to target flash memory); and (2) Writing the flash key codes in sequence to the flash lock register (FLKEY). The PSWE bit remains set until cleared by software. For detailed guidelines on programming flash from firmware, please see Section "12.5. Flash Write and Erase Guidelines" on page 154. To ensure the integrity of the flash contents, the on-chip VDD Monitor must be enabled and enabled as a reset source in any system that includes code that writes and/or erases flash memory from software. Furthermore, there should be no delay between enabling the VDD Monitor and enabling the VDD Monitor as a reset source. Any attempt to write or erase flash memory while the VDD Monitor is disabled, or not enabled as a reset source, will cause a flash error device reset. 12.1.1. Flash Lock and Key Functions Flash writes and erases by user software are protected with a lock and key function. The flash lock and key register (FLKEY) must be written with the correct key codes, in sequence, before flash operations may be performed. The key codes are: 0xA5, 0xF1. The timing does not matter, but the codes must be written in order. If the key codes are written out of order, or the wrong codes are written, flash writes and erases will be disabled until the next system reset. Flash writes and erases will also be disabled if a flash write or erase is attempted before the key codes have been written properly. The flash lock resets after each write or erase; the key codes must be written again before a following flash operation can be performed. The FLKEY register is detailed in SFR Definition 12.2. Rev. 1.0 149 Si106x/108x 12.1.2. Flash Erase Procedure The flash memory is organized in 1024-byte pages. The erase operation applies to an entire page (setting all bytes in the page to 0xFF). To erase an entire 1024-byte page, perform the following steps: 1. Save current interrupt state and disable interrupts. 2. Set the PSEE bit (register PSCTL). 3. Set the PSWE bit (register PSCTL). 4. Write the first key code to FLKEY: 0xA5. 5. Write the second key code to FLKEY: 0xF1. 6. Using the MOVX instruction, write a data byte to any location within the 1024-byte page to be erased. 7. Clear the PSWE and PSEE bits. 8. Restore previous interrupt state. Steps 4-6 must be repeated for each 1024-byte page to be erased. Notes: 1. Future 16 and 8 kB derivatives in this product family will use a 512-byte page size. To maintain code compatibility across the entire family, the erase procedure should be performed on each 512-byte section of memory. 2. Flash security settings may prevent erasure of some flash pages, such as the reserved area and the page containing the lock bytes. For a summary of flash security settings and restrictions affecting flash erase operations, please see Section "12.3. Security Options" on page 151. 3. 8-bit MOVX instructions cannot be used to erase or write to flash memory at addresses higher than 0x00FF. 12.1.3. Flash Write Procedure A write to flash memory can clear bits to logic 0 but cannot set them; only an erase operation can set bits to logic 1 in flash. A byte location to be programmed should be erased before a new value is written. The recommended procedure for writing a single byte in flash is as follows: 1. Save current interrupt state and disable interrupts. 2. Ensure that the flash byte has been erased (has a value of 0xFF). 3. Set the PSWE bit (register PSCTL). 4. Clear the PSEE bit (register PSCTL). 5. Write the first key code to FLKEY: 0xA5. 6. Write the second key code to FLKEY: 0xF1. 7. Using the MOVX instruction, write a single data byte to the desired location within the 1024-byte sector. 8. Clear the PSWE bit. 9. Restore previous interrupt state. Steps 5-7 must be repeated for each byte to be written. Notes: 1. Future 16 and 8 kB derivatives in this product family will use a 512-byte page size. To maintain code compatibility across the entire family, the erase procedure should be performed on each 512-byte section of memory. 2. Flash security settings may prevent writes to some areas of flash, such as the reserved area. For a summary of flash security settings and restrictions affecting flash write operations, please see Section "12.3. Security Options" on page 151. 150 Rev. 1.0 Si106x/108x 12.2. Non-Volatile Data Storage The flash memory can be used for non-volatile data storage as well as program code. This allows data such as calibration coefficients to be calculated and stored at run time. Data is written using the MOVX write instruction and read using the MOVC instruction. Note: MOVX read instructions always target XRAM. An additional 1024-byte scratchpad is available for non-volatile data storage. It is accessible at addresses 0x0000 to 0x03FF when SFLE is set to 1. The scratchpad area cannot be used for code execution. 12.3. Security Options The CIP-51 provides security options to protect the flash memory from inadvertent modification by software as well as to prevent the viewing of proprietary program code and constants. The Program Store Write Enable (bit PSWE in register PSCTL) and the Program Store Erase Enable (bit PSEE in register PSCTL) bits protect the flash memory from accidental modification by software. PSWE must be explicitly set to 1 before software can modify the flash memory; both PSWE and PSEE must be set to 1 before software can erase flash memory. Additional security features prevent proprietary program code and data constants from being read or altered across the C2 interface. A Security Lock Byte located at the last byte of flash user space offers protection of the flash program memory from access (reads, writes, or erases) by unprotected code or the C2 interface. The flash security mechanism allows the user to lock n 1024-byte flash pages, starting at page 0 (addresses 0x0000 to 0x03FF), where n is the 1s complement number represented by the Security Lock Byte. Note that the page containing the flash Security Lock Byte is unlocked when no other flash pages are locked (all bits of the Lock Byte are 1) and locked when any other flash pages are locked (any bit of the Lock Byte is 0). See the example below. Security Lock Byte: ones Complement: Flash pages locked: 11111101b 00000010b 3 (First two flash pages + Lock Byte Page) Addresses locked: 0x0000 to 0x07FF (first two flash pages) and 0xF800 to 0xFBFF (Lock Byte Page) 64KB Flash Device (SFLE = 0) 32KB Flash Device (SFLE = 0) 0xFFFF 0xFFFF Reserved Unpopulated Address Space (Reserved) 0xFC00 0xFBFF Lock Byte 0xFBFE Lock Byte Page 0xF800 Locked when any other Flash pages are locked 0x8000 Lock Byte Lock Byte Page Flash memory organized in 1024-byte pages 0x7FFF 0x7FFE 0x7C00 Unlocked Flash Pages 64/32KB Flash Device (SFLE = 1) Unlocked Flash Pages 0x0000 Access limit set according to the Flash security lock byte 0x03FF Scratchpad Area (Data Only) 0x0000 0x0000 Figure 12.1. Si106x Flash Program Memory Map Rev. 1.0 151 Si106x/108x Figure 12.2. Si108x Flash Program Memory Map The level of flash security depends on the flash access method. The three flash access methods that can be restricted are reads, writes, and erases from the C2 debug interface, user firmware executing on unlocked pages, and user firmware executing on locked pages. Table 12.1 summarizes the flash security features of the Si106x/108x devices. Table 12.1. Flash Security Summary Action C2 Debug Interface User Firmware executing from: an unlocked page Read, Write or Erase unlocked pages (except page with Lock Byte) Permitted Read, Write or Erase locked pages (except page with Lock Byte) Not Permitted FEDR Permitted Read or Write page containing Lock Byte (if no pages are locked) Permitted Permitted Read or Write page containing Lock Byte (if any page is locked) Not Permitted FEDR Permitted Read contents of Lock Byte (if no pages are locked) Permitted Permitted Read contents of Lock Byte (if any page is locked) Not Permitted FEDR Permitted Erase page containing Lock Byte (if no pages are locked) Permitted FEDR FEDR Erase page containing Lock Byte - Unlock all pages (if any page is locked) Only by C2DE FEDR FEDR Lock additional pages (change 1s to 0s in the Lock Byte) Not Permitted FEDR FEDR Unlock individual pages (change 0s to 1s in the Lock Byte) Not Permitted FEDR FEDR 152 Rev. 1.0 Permitted a locked page Permitted Permitted Permitted Si106x/108x Table 12.1. Flash Security Summary (Continued) Read, Write or Erase Reserved Area Not Permitted FEDR FEDR C2DE--C2 Device Erase (Erases all flash pages including the page containing the Lock Byte) FEDR--Not permitted; Causes Flash Error Device Reset (FERROR bit in RSTSRC is 1 after reset) - All prohibited operations that are performed via the C2 interface are ignored (do not cause device reset). - Locking any flash page also locks the page containing the Lock Byte. - Once written to, the Lock Byte cannot be modified except by performing a C2 Device Erase. - If user code writes to the Lock Byte, the Lock does not take effect until the next device reset. - The scratchpad is locked when all other flash pages are locked. - The scratchpad is erased when a Flash Device Erase command is performed. Rev. 1.0 153 Si106x/108x 12.4. Determining the Device Part Number at Run Time In many applications, user software may need to determine the MCU part number at run time in order to determine the hardware capabilities. The part number can be determined by reading the value of the flash byte at address 0xFFFE. The value of the flash byte at address 0xFFFE can be decoded as follows: 0xE0--Si1060/Si1080 0xE1--Si1061/Si1081 0xE2--Si1062/Si1082 0xE3--Si1063/Si1083 0xE4--Si1064/Si1084 0xE5--Si1065/Si1085 12.5. Flash Write and Erase Guidelines Any system which contains routines which write or erase flash memory from software involves some risk that the write or erase routines will execute unintentionally if the CPU is operating outside its specified operating range of VDD, system clock frequency, or temperature. This accidental execution of flash modifying code can result in alteration of flash memory contents causing a system failure that is only recoverable by re-flashing the code in the device. To help prevent the accidental modification of flash by firmware, the VDD Monitor must be enabled and enabled as a reset source on Si106x devices for the flash to be successfully modified. If either the VDD Monitor or the VDD Monitor reset source is not enabled, a Flash Error Device Reset will be generated when the firmware attempts to modify the flash. The following guidelines are recommended for any system that contains routines which write or erase flash from code. 12.5.1. VDD Maintenance and the VDD Monitor 1. If the system power supply is subject to voltage or current "spikes," add sufficient transient protection devices to the power supply to ensure that the supply voltages listed in the Absolute Maximum Ratings table are not exceeded. 2. Make certain that the minimum VDD rise time specification of 1 ms is met. If the system cannot meet this rise time specification, then add an external VDD brownout circuit to the RST pin of the device that holds the device in reset until VDD reaches the minimum device operating voltage and re-asserts RST if VDD drops below the minimum device operating voltage. 3. Keep the on-chip VDD Monitor enabled and enable the VDD Monitor as a reset source as early in code as possible. This should be the first set of instructions executed after the Reset Vector. For C-based systems, this will involve modifying the startup code added by the C compiler. See your compiler documentation for more details. Make certain that there are no delays in software between enabling the VDD Monitor and enabling the VDD Monitor as a reset source. Code examples showing this can be found in "AN201: Writing to Flash from Firmware," available from the Silicon Laboratories website. Notes: On Si106x/108x devices, both the VDD Monitor and the VDD Monitor reset source must be enabled to write or erase flash without generating a Flash Error Device Reset. On Si106x/108x devices, both the VDD Monitor and the VDD Monitor reset source are enabled by hardware after a power-on reset. 4. As an added precaution, explicitly enable the VDD Monitor and enable the VDD Monitor as a reset source inside the functions that write and erase flash memory. The VDD Monitor enable instructions should be placed just after the instruction to set PSWE to a 1, but before the flash write or erase operation instruction. 154 Rev. 1.0 Si106x/108x 5. Make certain that all writes to the RSTSRC (Reset Sources) register use direct assignment operators and explicitly DO NOT use the bit-wise operators (such as AND or OR). For example, "RSTSRC = 0x02" is correct, but "RSTSRC |= 0x02" is incorrect. 6. Make certain that all writes to the RSTSRC register explicitly set the PORSF bit to a 1. Areas to check are initialization code which enables other reset sources, such as the Missing Clock Detector or Comparator, for example, and instructions which force a Software Reset. A global search on "RSTSRC" can quickly verify this. 12.5.2. PSWE Maintenance 7. Reduce the number of places in code where the PSWE bit (b0 in PSCTL) is set to a 1. There should be exactly one routine in code that sets PSWE to a 1 to write flash bytes and one routine in code that sets both PSWE and PSEE both to a 1 to erase flash pages. 8. Minimize the number of variable accesses while PSWE is set to a 1. Handle pointer address updates and loop maintenance outside the "PSWE = 1;... PSWE = 0;" area. Code examples showing this can be found in "AN201: Writing to Flash from Firmware," available from the Silicon Laboratories website. 9. Disable interrupts prior to setting PSWE to a 1 and leave them disabled until after PSWE has been reset to 0. Any interrupts posted during the flash write or erase operation will be serviced in priority order after the flash operation has been completed and interrupts have been re-enabled by software. 10.Make certain that the flash write and erase pointer variables are not located in XRAM. See your compiler documentation for instructions regarding how to explicitly locate variables in different memory areas. 11. Add address bounds checking to the routines that write or erase flash memory to ensure that a routine called with an illegal address does not result in modification of the flash. 12.5.3. System Clock 12.If operating from an external crystal, be advised that crystal performance is susceptible to electrical interference and is sensitive to layout and to changes in temperature. If the system is operating in an electrically noisy environment, use the internal oscillator or use an external CMOS clock. 13.If operating from the external oscillator, switch to the internal oscillator during flash write or erase operations. The external oscillator can continue to run, and the CPU can switch back to the external oscillator after the flash operation has completed. Additional flash recommendations and example code can be found in "AN201: Writing to Flash from Firmware," available from the Silicon Laboratories website. Rev. 1.0 155 Si106x/108x 12.6. Minimizing Flash Read Current The flash memory in the Si106x/108x devices is responsible for a substantial portion of the total digital supply current when the device is executing code. Below are suggestions to minimize flash read current. 1. Use Idle, Suspend, or Sleep Modes while waiting for an interrupt, rather than polling the interrupt flag. Idle Mode is particularly well-suited for use in implementing short pauses, since the wake-up time is no more than three system clock cycles. See the Power Management chapter for details on the various low-power operating modes. 2. Si106x/108x devices have a one-shot timer that saves power when operating at system clock frequencies of 10 MHz or less. The one-shot timer generates a minimum-duration enable signal for the flash sense amps on each clock cycle in which the flash memory is accessed. This allows the flash to remain in a low power state for the remainder of the long clock cycle. At clock frequencies above 10 MHz, the system clock cycle becomes short enough that the one-shot timer no longer provides a power benefit. Disabling the one-shot timer at higher frequencies reduces power consumption. The one-shot is enabled by default, and it can be disabled (bypassed) by setting the BYPASS bit (FLSCL.6) to logic 1. To re-enable the one-shot, clear the BYPASS bit to logic 0. After changing the BYPASS bit from 1 to 0, the third opcode byte fetched from program memory is indeterminate. Therefore, the operation which clears the BYPASS bit should be immediately followed by a benign 3-byte instruction whose third byte is a don't care. An example of such an instruction is a 3byte MOV that targets the FLWR register. When programming in C, the dummy value written to FLWR should be a non-zero value to prevent the compiler from generating a 2-byte MOV instruction. 3. Flash read current depends on the number of address lines that toggle between sequential flash read operations. In most cases, the difference in power is relatively small (on the order of 5%). 4. The flash memory is organized in rows. Each row in the Si106x/108x flash contains 128 bytes. A substantial current increase can be detected when the read address jumps from one row in the flash memory to another. Consider a 3-cycle loop (e.g., SJMP $, or while(1);) which straddles a 128-byte flash row boundary. The flash address jumps from one row to another on two of every three clock cycles. This can result in a current increase of up 30% when compared to the same 3-cycle loop contained entirely within a single row. 5. To minimize the power consumption of small loops, it is best to locate them within a single row, if possible. To check if a loop is contained within a flash row, divide the starting address of the first instruction in the loop by 128. If the remainder (result of modulo operation) plus the length of the loop is less than 127, then the loop fits inside a single flash row. Otherwise, the loop will be straddling two adjacent flash rows. If a loop executes in 20 or more clock cycles, then the transitions from one row to another will occur on relatively few clock cycles, and any resulting increase in operating current will be negligible. Note: Future 16 and 8 kB derivatives in this product family will use a flash memory that is organized in rows of 64 bytes each. To maintain code compatibility across the entire family, it is best to locate small loops within a single 64-byte segment. 156 Rev. 1.0 Si106x/108x SFR Definition 12.1. PSCTL: Program Store R/W Control Bit 7 6 5 4 3 Name 2 1 0 SFLE PSEE PSWE Type R R R R R R/W R/W R/W Reset 0 0 0 0 0 0 0 0 SFR Page =0x0; SFR Address = 0x8F Bit Name 7:3 Unused 2 SFLE Function Read = 00000b, Write = don't care. Scratchpad Flash Memory Access Enable. When this bit is set, flash MOVC reads and MOVX writes from user software are directed to the Scratchpad flash sector. Flash accesses outside the address range 0x0000-0x03FF should not be attempted and may yield undefined results when SFLE is set to 1. 0: Flash access from user software directed to the Program/Data Flash sector. 1: Flash access from user software directed to the Scratchpad Sector. 1 PSEE Program Store Erase Enable. Setting this bit (in combination with PSWE) allows an entire page of flash program memory to be erased. If this bit is logic 1 and flash writes are enabled (PSWE is logic 1), a write to flash memory using the MOVX instruction will erase the entire page that contains the location addressed by the MOVX instruction. The value of the data byte written does not matter. 0: Flash program memory erasure disabled. 1: Flash program memory erasure enabled. 0 PSWE Program Store Write Enable. Setting this bit allows writing a byte of data to the flash program memory using the MOVX write instruction. The flash location should be erased before writing data. 0: Writes to flash program memory disabled. 1: Writes to flash program memory enabled; the MOVX write instruction targets flash memory. Rev. 1.0 157 Si106x/108x SFR Definition 12.2. FLKEY: Flash Lock and Key Bit 7 6 5 4 3 Name FLKEY[7:0] Type R/W Reset 0 0 0 0 SFR Page = 0x0; SFR Address = 0xB6 Bit Name 7:0 0 2 1 0 0 0 0 Function FLKEY[7:0] Flash Lock and Key Register. Write: This register provides a lock and key function for flash erasures and writes. Flash writes and erases are enabled by writing 0xA5 followed by 0xF1 to the FLKEY register. Flash writes and erases are automatically disabled after the next write or erase is complete. If any writes to FLKEY are performed incorrectly, or if a flash write or erase operation is attempted while these operations are disabled, the flash will be permanently locked from writes or erasures until the next device reset. If an application never writes to flash, it can intentionally lock the flash by writing a non-0xA5 value to FLKEY from software. Read: When read, bits 1-0 indicate the current flash lock state. 00: Flash is write/erase locked. 01: The first key code has been written (0xA5). 10: Flash is unlocked (writes/erases allowed). 11: Flash writes/erases disabled until the next reset. 158 Rev. 1.0 Si106x/108x SFR Definition 12.3. FLSCL: Flash Scale Bit 7 6 5 4 3 2 1 0 BYPASS Name Type R R/W R R R R R R Reset 0 0 0 0 0 0 0 0 SFR Page = 0x0; SFR Address = 0xB6 Bit Name Function 7 Reserved Always Write to 0. 6 BYPASS Flash Read Timing One-Shot Bypass. 0: The one-shot determines the flash read time. This setting should be used for operating frequencies less than 10 MHz. 1: The system clock determines the flash read time. This setting should be used for frequencies greater than 10 MHz. 5:0 Reserved Always Write to 000000. Note: When changing the BYPASS bit from 1 to 0, the third opcode byte fetched from program memory is indeterminate. Therefore, the operation which clears the BYPASS bit should be immediately followed by a benign 3-byte instruction whose third byte is a don't care. An example of such an instruction is a 3-byte MOV that targets the FLWR register. When programming in C, the dummy value written to FLWR should be a nonzero value to prevent the compiler from generating a 2-byte MOV instruction. SFR Definition 12.4. FLWR: Flash Write Only Bit 7 6 5 4 Name FLWR[7:0] Type W Reset 0 0 0 0 SFR Page = 0x0; SFR Address = 0xE5 Bit Name 7:0 3 2 1 0 0 0 0 0 Function FLWR[7:0] Flash Write Only. All writes to this register have no effect on system operation. Rev. 1.0 159 Si106x/108x 13. Power Management Si106x/108x devices support 5 power modes: Normal, Idle, Stop, Suspend, and Sleep. The power management unit (PMU0) allows the device to enter and wake-up from the available power modes. A brief description of each power mode is provided in Table 13.1. Detailed descriptions of each mode can be found in the following sections. Table 13.1. Power Modes Power Mode Description Wake-Up Sources Power Savings N/A Excellent MIPS/mW Normal Device fully functional Idle All peripherals fully functional. Very easy to wake up. Any Interrupt Good No Code Execution Stop Legacy 8051 low power mode. A reset is required to wake up. Any Reset Good No Code Execution Precision Oscillator Disabled Suspend Similar to Stop Mode, but very fast wake-up time and code resumes execution at the next instruction. SmaRTClock, Port Match, Comparator0, RST pin Very Good No Code Execution All Internal Oscillators Disabled System Clock Gated Sleep Ultra Low Power and flexible wake-up sources. Code resumes execution at the next instruction. Comparator0 only functional in two-cell mode. SmaRTClock, Port Match, Comparator0, RST pin Excellent Power Supply Gated All Oscillators except SmaRTClock Disabled In battery powered systems, the system should spend as much time as possible in Sleep mode in order to preserve battery life. When a task with a fixed number of clock cycles needs to be performed, the device should switch to Normal mode, finish the task as quickly as possible, and return to Sleep mode. Idle Mode and Suspend modes provide a very fast wake-up time; however, the power savings in these modes will not be as much as in Sleep Mode. Stop Mode is included for legacy reasons; the system will be more power efficient and easier to wake up when Idle, Suspend, or Sleep Mode are used. Although switching power modes is an integral part of power management, enabling/disabling individual peripherals as needed will help lower power consumption in all power modes. Each analog peripheral can be disabled when not in use or placed in a low power mode. Digital peripherals such as timers or serial buses draw little power whenever they are not in use. Digital peripherals draw no power in Sleep Mode. Rev. 1.0 160 Si106x/108x 13.1. Normal Mode The MCU is fully functional in Normal Mode. Figure 13.1 shows the on-chip power distribution to various peripherals. There are three supply voltages powering various sections of the device: VBAT, VDD/DC+, and the 1.8 V internal core supply. VREG0, PMU0 and the SmaRTClock are always powered directly from the VBAT pin. All analog peripherals are directly powered from the VDD/DC+ pin, which is an output in one-cell mode and an input in two-cell mode. All digital peripherals and the CIP-51 core are powered from the 1.8 V internal core supply. The RAM is also powered from the core supply in Normal mode. VBAT One-cell: 0.9 to 1.8 V Two-cell: 1.8 to 3.6 V VDD/DC+ Note: VDD/DC+ must be > VBAT 1.9 V typical DC0 One-cell or Two-cell: 1.8 to 3.6 V GPIO Analog Peripherals One-Cell Active/ Idle/Stop/Suspend One-Cell Sleep VREF VREG0 A M U X 10-bit 300 ksps ADC TEMP SENSOR Sleep Active/Idle/ Stop/Suspend 1.8 V + + - VOLTAGE COMPARATORS Digital Peripherals UART PMU0 SmaRTClock CIP-51 Core RAM Flash SPI Timers Figure 13.1. Si106x/108x Power Distribution 161 Rev. 1.0 SMBus Si106x/108x 13.2. Idle Mode Setting the Idle Mode Select bit (PCON.0) causes the CIP-51 to halt the CPU and enter Idle mode as soon as the instruction that sets the bit completes execution. All internal registers and memory maintain their original data. All analog and digital peripherals can remain active during Idle mode. Note: To ensure the MCU enters a low power state upon entry into Idle Mode, the one-shot circuit should be enabled by clearing the BYPASS bit (FLSCL.6) to logic 0. See the note in SFR Definition 12.3. FLSCL: Flash Scale for more information on how to properly clear the BYPASS bit. Idle mode is terminated when an enabled interrupt is asserted or a reset occurs. The assertion of an enabled interrupt will cause the Idle Mode Selection bit (PCON.0) to be cleared and the CPU to resume operation. The pending interrupt will be serviced and the next instruction to be executed after the return from interrupt (RETI) will be the instruction immediately following the one that set the Idle Mode Select bit. If Idle mode is terminated by an internal or external reset, the CIP-51 performs a normal reset sequence and begins program execution at address 0x0000. If enabled, the Watchdog Timer (WDT) will eventually cause an internal watchdog reset and thereby terminate the Idle mode. This feature protects the system from an unintended permanent shutdown in the event of an inadvertent write to the PCON register. If this behavior is not desired, the WDT may be disabled by software prior to entering the Idle mode if the WDT was initially configured to allow this operation. This provides the opportunity for additional power savings, allowing the system to remain in the Idle mode indefinitely, waiting for an external stimulus to wake up the system. Refer to Section "17.6. PCA Watchdog Timer Reset" on page 190 for more information on the use and configuration of the WDT. 13.3. Stop Mode Setting the Stop Mode Select bit (PCON.1) causes the CIP-51 to enter Stop mode as soon as the instruction that sets the bit completes execution. In Stop mode the precision internal oscillator and CPU are stopped; the state of the low power oscillator and the external oscillator circuit is not affected. Each analog peripheral (including the external oscillator circuit) may be shut down individually prior to entering Stop Mode. Stop mode can only be terminated by an internal or external reset. On reset, the CIP-51 performs the normal reset sequence and begins program execution at address 0x0000. If enabled, the Missing Clock Detector will cause an internal reset and thereby terminate the Stop mode. The Missing Clock Detector should be disabled if the CPU is to be put to in STOP mode for longer than the MCD timeout of 100 s. Stop Mode is a legacy 8051 power mode; it will not result in optimal power savings. Sleep or Suspend mode will provide more power savings if the MCU needs to be inactive for a long period of time. On Si106x/108x devices, the Precision Oscillator Bias is not automatically disabled and should be disabled by software to achieve the lowest possible Stop mode current. Note: To ensure the MCU enters a low power state upon entry into Stop Mode, the one-shot circuit should be enabled by clearing the BYPASS bit (FLSCL.6) to logic 0. See the note in SFR Definition 12.3. FLSCL: Flash Scale for more information on how to properly clear the BYPASS bit. Rev. 1.0 162 Si106x/108x 13.4. Suspend Mode Setting the Suspend Mode Select bit (PMU0CF.6) causes the system clock to be gated off and all internal oscillators disabled. All digital logic (timers, communication peripherals, interrupts, CPU, etc.) stops functioning until one of the enabled wake-up sources occurs. Important Notes: When entering Suspend Mode, the global clock divider must be set to "divide by 1" by setting CLKDIV[2:0] = 000b in the CLKSEL register. The one-shot circuit should be enabled by clearing the BYPASS bit (FLSCL.6) to logic 0. See the note in SFR Definition 12.3. FLSCL: Flash Scale for more information on how to properly clear the BYPASS bit. Upon wake-up from suspend mode, PMU0 requires two system clocks in order to update the PMU0CF wake-up flags. All flags will read back a value of 0 during the first two system clocks following a wake-up from suspend mode. The system clock source must be set to the low power internal oscillator or the precision oscillator prior to entering suspend mode. The following wake-up sources can be configured to wake the device from suspend mode: SmaRTClock Oscillator Fail SmaRTClock Alarm Port Match Event Comparator0 Rising Edge In addition, a noise glitch on RST that is not long enough to reset the device will cause the device to exit suspend. In order for the MCU to respond to the pin reset event, software must not place the device back into suspend mode for a period of 15 s. The PMU0CF register may be checked to determine if the wakeup was due to a falling edge on the /RST pin. If the wake-up source is not due to a falling edge on RST, there is no time restriction on how soon software may place the device back into suspend mode. A 4.7 k pullup resistor to VDD_MCU/DC+ is recommend for RST to prevent noise glitches from waking the device. 13.5. Sleep Mode Setting the Sleep Mode Select bit (PMU0CF.6) turns off the internal 1.8 V regulator (VREG0) and switches the power supply of all on-chip RAM to the VDD_MCU pin (see Figure 13.1). Power to most digital logic on the device is disconnected; only PMU0 and the SmaRTClock remain powered. Analog peripherals remain powered. The Comparators remain functional when the device enters sleep mode. All other analog peripherals (ADC0, External Oscillator, etc.) should be disabled prior to entering sleep mode. The system clock source must be set to the low power internal oscillator or the precision oscillator prior to entering sleep mode. Important Notes: When entering Sleep Mode, the global clock divider must be set to "divide by 1" by setting CLKDIV[2:0] = 000b in the CLKSEL register. Any write to PMU0CF which places the device in sleep mode should be immediately followed by two NOP instructions. Software that does not place two NOP instructions immediately following the write to PMU0CF should continue to behave the same way as during software development. GPIO pins configured as digital outputs will retain their output state during sleep mode. In two-cell mode, they will maintain the same current drive capability in sleep mode as they have in normal mode. In one-cell mode, the VDD_MCU/DC+ supply will drop to the level of VBAT, which will reduce the output high-voltage level and the source and sink current drive capability. GPIO pins configured as digital inputs can be used during sleep mode as wakeup sources using the port match feature. In two-cell mode, they will maintain the same input level specifications in sleep mode as they have in normal mode. In one-cell mode, the VDD supply will drop to the level of VBAT, which will lower the switching threshold and increase the propagation delay. 163 Rev. 1.0 Si106x/108x Note: By default, the VDD/DC+ supply is connected to VBAT upon entry into Sleep Mode (one-cell mode). If the VDDSLP bit (DC0CF.1) is set to logic 1, the VDD/DC+ supply will float in Sleep Mode. This allows the decoupling capacitance on the VDD/DC+ supply to maintain the supply rail until the capacitors are discharged. For relatively short sleep intervals, this can result in substantial power savings because the decoupling capacitance is not continuously charged and discharged. RAM and SFR register contents are preserved in sleep mode as long as the voltage on VBAT (or VDD_MCU on Si1060/61/80/81 devices) does not fall below VPOR. The PC counter and all other volatile state information is preserved allowing the device to resume code execution upon waking up from sleep mode. The following wake-up sources can be configured to wake the device from sleep mode: SmaRTClock Oscillator Fail SmaRTClock Alarm Port Match Event Comparator0 Rising Edge The Comparator0 Rising Edge wakeup is only valid in two-cell mode. The comparator requires a supply voltage of at least 1.8 V to operate properly. In addition, any falling edge on RST (due to a pin reset or a noise glitch) will cause the device to exit sleep mode. In order for the MCU to respond to the pin reset event, software must not place the device back into sleep mode for a period of 15 s. The PMU0CF register may be checked to determine if the wake-up was due to a falling edge on the RST pin. If the wake-up source is not due to a falling edge on RST, there is no time restriction on how soon software may place the device back into sleep mode. A 4.7 k pullup resistor to VDD_MCU/DC+ is recommend for RST to prevent noise glitches from waking the device. 13.6. Configuring Wakeup Sources Before placing the device in a low power mode, one or more wakeup sources should be enabled so that the device does not remain in the low power mode indefinitely. For Idle Mode, this includes enabling any interrupt. For stop mode, this includes enabling any reset source or relying on the RST pin to reset the device. Wake-up sources for suspend and sleep modes are configured through the PMU0CF register. Wake-up sources are enabled by writing 1 to the corresponding wake-up source enable bit. Wake-up sources must be re-enabled each time the device is placed in suspend or sleep mode, in the same write that places the device in the low power mode. The reset pin is always enabled as a wake-up source. On the falling edge of RST, the device will be awaken from sleep mode. The device must remain awake for more than 15 s in order for the reset to take place. 13.7. Determining the Event that Caused the Last Wakeup When waking from Idle Mode, the CPU will vector to the interrupt which caused it to wake up. When waking from Stop mode, the RSTSRC register may be read to determine the cause of the last reset. Upon exit from Suspend or Sleep mode, the wake-up flags in the PMU0CF register can be read to determine the event which caused the device to wake up. After waking up, the wake-up flags will continue to be updated if any of the wake-up events occur. Wake-up flags are always updated, even if they are not enabled as wake-up sources. All wake-up flags enabled as wake-up sources in PMU0CF must be cleared before the device can enter suspend or sleep mode. After clearing the wake-up flags, each of the enabled wake-up events should be checked in the individual peripherals to ensure that a wake-up event did not occur while the wake-up flags were being cleared. Rev. 1.0 164 Si106x/108x SFR Definition 13.1. PMU0CF: Power Management Unit Configuration1,2 Bit 7 6 5 4 3 2 1 0 Name SLEEP SUSPEND CLEAR RSTWK RTCFWK RTCAWK PMATWK CPT0WK Type W W W R R/W R/W R/W R/W Reset 0 0 0 Varies Varies Varies Varies Varies SFR Page = 0x0; SFR Address = 0xB5 Bit Name Description 7 SLEEP 6 SUSPEND 5 Write Read Sleep Mode Select Writing 1 places the device in Sleep Mode. N/A Suspend Mode Select Writing 1 places the device in Suspend Mode. N/A CLEAR Wake-up Flag Clear Writing 1 clears all wakeup flags. N/A 4 RSTWK Reset Pin Wake-up Flag N/A Set to 1 if a falling edge has been detected on RST. 3 RTCFWK SmaRTClock Oscillator Fail Wake-up Source Enable and Flag 0: Disable wake-up on SmaRTClock Osc. Fail. 1: Enable wake-up on SmaRTClock Osc. Fail. Set to 1 if the SmaRTClock Oscillator has failed. 2 RTCAWK SmaRTClock Alarm Wake-up Source Enable and Flag 0: Disable wake-up on SmaRTClock Alarm. 1: Enable wake-up on SmaRTClock Alarm. Set to 1 if a SmaRTClock Alarm has occurred. 1 PMATWK Port Match Wake-up Source Enable and Flag 0: Disable wake-up on Port Match Event. 1: Enable wake-up on Port Match Event. Set to 1 if a Port Match Event has occurred. 0 CPT0WK Comparator0 Wake-up Source Enable and Flag 0: Disable wake-up on Comparator0 rising edge. 1: Enable wake-up on Comparator0 rising edge. Set to 1 if Comparator0 rising edge caused the last wake-up. Notes: 1. Read-modify-write operations (ORL, ANL, etc.) should not be used on this register. Wake-up sources must be re-enabled each time the SLEEP or SUSPEND bits are written to 1. 2. The Low Power Internal Oscillator cannot be disabled and the MCU cannot be placed in Suspend or Sleep Mode if any wake-up flags are set to 1. Software should clear all wake-up sources after each reset and after each wake-up from Suspend or Sleep Modes. 165 Rev. 1.0 Si106x/108x SFR Definition 13.2. PCON: Power Management Control Register Bit 7 6 5 4 3 2 1 0 Name GF[5:0] STOP IDLE Type R/W W W 0 0 Reset 0 0 0 0 SFR Page = All Pages; SFR Address = 0x87 Bit Name Description 7:2 GF[5:0] 1 0 0 0 Write Read General Purpose Flags Sets the logic value. Returns the logic value. STOP Stop Mode Select Writing 1 places the device in Stop Mode. N/A IDLE Idle Mode Select Writing 1 places the device in Idle Mode. N/A 13.8. Power Management Specifications See Table 4.5 on page 58 for detailed Power Management Specifications. Rev. 1.0 166 Si106x/108x 14. Cyclic Redundancy Check Unit (CRC0) Si106x/108x devices include a cyclic redundancy check unit (CRC0) that can perform a CRC using a 16-bit or 32-bit polynomial. CRC0 accepts a stream of 8-bit data written to the CRC0IN register. CRC0 posts the 16-bit or 32-bit result to an internal register. The internal result register may be accessed indirectly using the CRC0PNT bits and CRC0DAT register, as shown in Figure 14.1. CRC0 also has a bit reverse register for quick data manipulation. 8 CRC0CN CRC0IN 8 Automatic CRC Controller Flash Memory CRC0AUTO CRC0SEL CRC0INIT CRC0VAL CRC0PNT1 CRC0PNT0 CRC Engine CRC0CNT 32 RESULT CRC0FLIP Write 8 8 8 8 4 to 1 MUX 8 CRC0DAT CRC0FLIP Read Figure 14.1. CRC0 Block Diagram 14.1. 16-bit CRC Algorithm The Si106x/108x CRC unit calculates the 16-bit CRC MSB-first, using a poly of 0x1021. The following describes the 16-bit CRC algorithm performed by the hardware: 1. XOR the input with the most-significant bits of the current CRC result. If this is the first iteration of the CRC unit, the current CRC result will be the set initial value (0x0000 or 0xFFFF). 2a. If the MSB of the CRC result is set, left-shift the CRC result and XOR the result with the selected polynomial (0x1021). 2b. If the MSB of the CRC result is not set, left-shift the CRC result. Repeat Steps 2a/2b for the number of input bits (8). The algorithm is also described in the following example. The 16-bit Si106x/108x CRC algorithm can be described by the following code: unsigned short UpdateCRC (unsigned short CRC_acc, unsigned char CRC_input) { unsigned char i; // loop counter #define POLY 0x1021 Rev. 1.0 167 Si106x/108x // Create the CRC "dividend" for polynomial arithmetic (binary arithmetic // with no carries) CRC_acc = CRC_acc ^ (CRC_input << 8); // "Divide" the poly into the dividend using CRC XOR subtraction // CRC_acc holds the "remainder" of each divide // // Only complete this division for 8 bits since input is 1 byte for (i = 0; i < 8; i++) { // Check if the MSB is set (if MSB is 1, then the POLY can "divide" // into the "dividend") if ((CRC_acc & 0x8000) == 0x8000) { // if so, shift the CRC value, and XOR "subtract" the poly CRC_acc = CRC_acc << 1; CRC_acc ^= POLY; } else { // if not, just shift the CRC value CRC_acc = CRC_acc << 1; } } // Return the final remainder (CRC value) return CRC_acc; } The following table lists several input values and the associated outputs using the 16-bit Si106x/108x CRC algorithm: Table 14.1. Example 16-bit CRC Outputs 168 Input Output 0x63 0xBD35 0x8C 0xB1F4 0x7D 0x4ECA 0xAA, 0xBB, 0xCC 0x6CF6 0x00, 0x00, 0xAA, 0xBB, 0xCC 0xB166 Rev. 1.0 Si106x/108x 14.2. 32-bit CRC Algorithm The Si106x CRC unit calculates the 32-bit CRC using a poly of 0x04C11DB7. The CRC-32 algorithm is "reflected", meaning that all of the input bytes and the final 32-bit output are bit-reversed in the processing engine. The following is a description of a simplified CRC algorithm that produces results identical to the hardware: Step 1. XOR the least-significant byte of the current CRC result with the input byte. If this is the first iteration of the CRC unit, the current CRC result will be the set initial value (0x00000000 or 0xFFFFFFFF). Step 2. Right-shift the CRC result. Step 3. If the LSB of the CRC result is set, XOR the CRC result with the reflected polynomial (0xEDB88320). Step 4. Repeat at Step 2 for the number of input bits (8). For example, the 32-bit Si106x CRC algorithm can be described by the following code: unsigned long UpdateCRC (unsigned long CRC_acc, unsigned char CRC_input) { unsigned char i; // loop counter #define POLY 0xEDB88320 // bit-reversed version of the poly 0x04C11DB7 // Create the CRC "dividend" for polynomial arithmetic (binary arithmetic // with no carries) CRC_acc = CRC_acc ^ CRC_input; // "Divide" the poly into the dividend using CRC XOR subtraction // CRC_acc holds the "remainder" of each divide // // Only complete this division for 8 bits since input is 1 byte for (i = 0; i < 8; i++) { // Check if the MSB is set (if MSB is 1, then the POLY can "divide" // into the "dividend") if ((CRC_acc & 0x00000001) == 0x00000001) { // if so, shift the CRC value, and XOR "subtract" the poly CRC_acc = CRC_acc >> 1; CRC_acc ^= POLY; } else { // if not, just shift the CRC value CRC_acc = CRC_acc >> 1; } } // Return the final remainder (CRC value) return CRC_acc; } The following table lists several input values and the associated outputs using the 32-bit Si106x CRC algorithm (an initial value of 0xFFFFFFFF is used): Rev. 1.0 169 Si106x/108x Table 14.2. Example 32-bit CRC Outputs Input Output 0x63 0xF9462090 0xAA, 0xBB, 0xCC 0x41B207B3 0x00, 0x00, 0xAA, 0xBB, 0xCC 0x78D129BC 14.3. Preparing for a CRC Calculation To prepare CRC0 for a CRC calculation, software should select the desired polynomial and set the initial value of the result. Two polynomials are available: 0x1021 (16-bit) and 0x04C11DB7 (32-bit). The CRC0 result may be initialized to one of two values: 0x00000000 or 0xFFFFFFFF. The following steps can be used to initialize CRC0. 1. Select a polynomial (Set CRC0SEL to 0 for 32-bit or 1 for 16-bit). 2. Select the initial result value (Set CRC0VAL to 0 for 0x00000000 or 1 for 0xFFFFFFFF). 3. Set the result to its initial value (Write 1 to CRC0INIT). 14.4. Performing a CRC Calculation Once CRC0 is initialized, the input data stream is sequentially written to CRC0IN, one byte at a time. The CRC0 result is automatically updated after each byte is written. The CRC engine may also be configured to automatically perform a CRC on one or more Flash sectors. The following steps can be used to automatically perform a CRC on Flash memory. 1. Prepare CRC0 for a CRC calculation as shown above. 2. Write the index of the starting page to CRC0AUTO. 3. Set the AUTOEN bit in CRC0AUTO. 4. Write the number of Flash sectors to perform in the CRC calculation to CRC0CNT. Note: Each Flash sector is 1024 bytes. 5. Write any value to CRC0CN (or OR its contents with 0x00) to initiate the CRC calculation. The CPU will not execute code any additional code until the CRC operation completes. 6. After initiating an automatic CRC calculation, the third opcode byte fetched from program memory is indeterminate. Therefore, writes to CRC0CN that initiate a CRC operation must be immediately followed by a benign 3-byte instruction whose third byte is a don't care. An example of such an instruction is a 3-byte MOV that targets the CRC0FLIP register. When programming in C, the dummy value written to CRC0FLIP should be a non-zero value to prevent the compiler from generating a 2-byte MOV instruction. 7. Clear the AUTOEN bit in CRC0AUTO. 8. Read the CRC result using the procedure below. 14.5. Accessing the CRC0 Result The internal CRC0 result is 32-bits (CRC0SEL = 0b) or 16-bits (CRC0SEL = 1b). The CRC0PNT bits select the byte that is targeted by read and write operations on CRC0DAT and increment after each read or write. The calculation result will remain in the internal CR0 result register until it is set, overwritten, or additional data is written to CRC0IN. 170 Rev. 1.0 Si106x/108x SFR Definition 14.1. CRC0CN: CRC0 Control Bit 7 6 5 4 3 2 CRC0SEL CRC0INIT CRC0VAL Name Type R/W R/W R/W R/W R/W R/W Reset 0 0 0 0 0 0 SFR Page = 0xF; SFR Address = 0x92 Bit Name 7:5 Unused 4 CRC0SEL 1 0 CRC0PNT[1:0] R/W 0 0 Function Read = 000b; Write = Don't Care. CRC0 Polynomial Select Bit. This bit selects the CRC0 polynomial and result length (32-bit or 16-bit). 0: CRC0 uses the 32-bit polynomial 0x04C11DB7 for calculating the CRC result. 1: CRC0 uses the 16-bit polynomial 0x1021 for calculating the CRC result. 3 CRC0INIT CRC0 Result Initialization Bit. Writing a 1 to this bit initializes the entire CRC result based on CRC0VAL. 2 CRC0VAL CRC0 Set Value Initialization Bit. This bit selects the set value of the CRC result. 0: CRC result is set to 0x00000000 on write of 1 to CRC0INIT. 1: CRC result is set to 0xFFFFFFFF on write of 1 to CRC0INIT. 1:0 CRC0PNT[1:0] CRC0 Result Pointer. Specifies the byte of the CRC result to be read/written on the next access to CRC0DAT. The value of these bits will auto-increment upon each read or write. For CRC0SEL = 0: 00: CRC0DAT accesses bits 7-0 of the 32-bit CRC result. 01: CRC0DAT accesses bits 15-8 of the 32-bit CRC result. 10: CRC0DAT accesses bits 23-16 of the 32-bit CRC result. 11: CRC0DAT accesses bits 31-24 of the 32-bit CRC result. For CRC0SEL = 1: 00: CRC0DAT accesses bits 7-0 of the 16-bit CRC result. 01: CRC0DAT accesses bits 15-8 of the 16-bit CRC result. 10: CRC0DAT accesses bits 7-0 of the 16-bit CRC result. 11: CRC0DAT accesses bits 15-8 of the 16-bit CRC result. Note: Upon initiation of an automatic CRC calculation, the third opcode byte fetched from program memory is indeterminate. Therefore, writes to CRC0CN that initiate a CRC operation must be immediately followed by a benign 3-byte instruction whose third byte is a don't care. An example of such an instruction is a 3-byte MOV that targets the CRC0FLIP register. When programming in `C', the dummy value written to CRC0FLIP should be a non-zero value to prevent the compiler from generating a 2-byte MOV instruction. Rev. 1.0 171 Si106x/108x SFR Definition 14.2. CRC0IN: CRC0 Data Input Bit 7 6 5 4 3 Name CRC0IN[7:0] Type R/W Reset 0 0 0 0 0 SFR Page = 0xF; SFR Address = 0x93 Bit Name 7:0 CRC0IN[7:0] 2 1 0 0 0 0 Function CRC0 Data Input. Each write to CRC0IN results in the written data being computed into the existing CRC result according to the CRC algorithm described in Section 14.1 SFR Definition 14.3. CRC0DAT: CRC0 Data Output Bit 7 6 5 4 3 Name CRC0DAT[7:0] Type R/W Reset 0 0 0 0 SFR Page = 0xF; SFR Address = 0x91 Bit Name 0 2 1 0 0 0 0 Function 7:0 CRC0DAT[7:0] CRC0 Data Output. Each read or write performed on CRC0DAT targets the CRC result bits pointed to by the CRC0 Result Pointer (CRC0PNT bits in CRC0CN). 172 Rev. 1.0 Si106x/108x SFR Definition 14.4. CRC0AUTO: CRC0 Automatic Control Bit 7 6 Name AUTOEN CRCDONE 5 4 3 2 1 CRC0ST[5:0] R/W Type Reset 0 1 0 AUTOEN R/W 0 SFR Page = 0xF; SFR Address = 0x96 Bit Name 7 0 0 0 0 0 Function Automatic CRC Calculation Enable. When AUTOEN is set to 1, any write to CRC0CN will initiate an automatic CRC starting at Flash sector CRC0ST and continuing for CRC0CNT sectors. 6 CRCDONE CRCDONE Automatic CRC Calculation Complete. Set to '0' when a CRC calculation is in progress. Note that code execution is stopped during a CRC calculation, therefore reads from firmware will always return '1'. 5:0 CRC0ST[5:0] Automatic CRC Calculation Starting Flash Sector. These bits specify the Flash sector to start the automatic CRC calculation. The starting address of the first Flash sector included in the automatic CRC calculation is CRC0ST x 1024. SFR Definition 14.5. CRC0CNT: CRC0 Automatic Flash Sector Count Bit 7 6 5 4 1 R/W Type Reset 0 0 0 0 SFR Page = 0xF; SFR Address = 0x97 Bit Name 5:0 2 0 CRC0CNT[5:0] Name 7:6 3 Unused R/W 0 0 0 0 Function Read = 00b; Write = Don't Care. CRC0CNT[5:0] Automatic CRC Calculation Flash Sector Count. These bits specify the number of Flash sectors to include in an automatic CRC calculation. The starting address of the last Flash sector included in the automatic CRC calculation is (CRC0ST+CRC0CNT) x 1024. Rev. 1.0 173 Si106x/108x 14.6. CRC0 Bit Reverse Feature CRC0 includes hardware to reverse the bit order of each bit in a byte as shown in Figure 14.2. Each byte of data written to CRC0FLIP is read back bit reversed. For example, if 0xC0 is written to CRC0FLIP, the data read back is 0x03. Bit reversal is a useful mathematical function used in algorithms such as the FFT. CRC0FLIP Write CRC0FLIP Read Figure 14.2. Bit Reverse Register SFR Definition 14.6. CRC0FLIP: CRC0 Bit Flip Bit 7 6 5 4 3 Name CRC0FLIP[7:0] Type R/W Reset 0 0 0 0 SFR Page = 0xF; SFR Address = 0x95 Bit Name 7:0 CRC0FLIP[7:0] 0 2 1 0 0 0 0 Function CRC0 Bit Flip. Any byte written to CRC0FLIP is read back in a bit-reversed order, i.e. the written LSB becomes the MSB. For example: If 0xC0 is written to CRC0FLIP, the data read back will be 0x03. If 0x05 is written to CRC0FLIP, the data read back will be 0xA0. 174 Rev. 1.0 Si106x/108x 15. On-Chip DC-DC Converter (DC0) Si1062/3/4/5, Si1082/3/4/5 devices include an on-chip dc-dc converter to allow operation from a single cell battery with a supply voltage as low as 0.9 V. The dc-dc converter is a switching boost converter with an input voltage range of 0.9 to 1.8 V and a programmable output voltage range of 1.8 to 3.3 V. The default output voltage is 1.9 V. The dc-dc converter can supply the system with up to 65 mW of regulated power (or up to 100 mW in some applications) and can be used for powering other devices in the system. This allows the most flexibility when interfacing to sensors and other analog signals which typically require a higher supply voltage than a single-cell battery can provide. Figure 15.1 shows a block diagram of the dc-dc converter. During normal operation in the first half of the switching cycle, the Duty Cycle Control switch is closed and the Diode Bypass switch is open. Since the output voltage is higher than the voltage at the DCEN pin, no current flows through the diode and the load is powered from the output capacitor. During this stage, the DCEN pin is connected to ground through the Duty Cycle Control switch, generating a positive voltage across the inductor and forcing its current to ramp up. In the second half of the switching cycle, the Duty Cycle control switch is opened and the Diode Bypass switch is closed. This connects DCEN directly to VDD_MCU/DC+ and forces the inductor current to charge the output capacitor. Once the inductor transfers its stored energy to the output capacitor, the Duty Cycle Control switch is closed, the Diode Bypass switch is opened, and the cycle repeats. The dc-dc converter has a built in voltage reference and oscillator, and will automatically limit or turn off the switching activity in case the peak inductor current rises beyond a safe limit or the output voltage rises above the programmed target value. This allows the dc-dc converter output to be safely overdriven by a secondary power source (when available) in order to preserve battery life. The dc-dc converter's settings can be modified using SFR registers which provide the ability to change the target output voltage, oscillator frequency or source, Diode Bypass switch resistance, peak inductor current, and minimum duty cycle. DC/DC Converter VBAT VDD_MCU/DC+ 0.68 uH DCEN Diode Bypass 4.7 uF Duty Cycle Control GND/VBAT- Control Logic DC0CN Voltage Reference DC0CF DC/DC Oscillator Lparasitic Lparasitic 1uF Iload Cload GND_MCU/DC- Figure 15.1. DC-DC Converter Block Diagram Rev. 1.0 175 Si106x/108x 15.1. Startup Behavior On initial power-on, the dc-dc converter outputs a constant 50% duty cycle until there is sufficient voltage on the output capacitor to maintain regulation. The size of the output capacitor and the amount of load current present during startup will determine the length of time it takes to charge the output capacitor. During initial power-on reset, the maximum peak inductor current threshold, which triggers the overcurrent protection circuit, is set to approximately 125 mA. This generates a "soft-start" to limit the output voltage slew rate and prevent excessive in-rush current at the output capacitor. In order to ensure reliable startup of the dc-dc converter, the following restrictions have been imposed: * The maximum dc load current allowed during startup is given in Table 4.14 on page 66. If the dc-dc converter is powering external sensors or devices through the VDD_MCU/DC+ pin or through GPIO pins, then the current supplied to these sensors or devices is counted towards this limit. The in-rush current into capacitors does not count towards this limit. * The maximum total output capacitance is given in Table 4.14 on page 66. This value includes the required 1 F ceramic output capacitor and any additional capacitance connected to the VDD_MCU/DC+ pin. Once initial power-on is complete, the peak inductor current limit can be increased by software as shown in Table 15.1. Limiting the peak inductor current can allow the device to start up near the battery's end of life. . Table 15.1. IPeak Inductor Current Limit Settings SWSEL ILIMIT Peak Current (mA) 1 0 100 0 0 125 1 1 250 0 1 500 The peak inductor current is dependent on several factors including the dc load current and can be estimated using following equation: I PK = 2 I LOAD VDD/DC+ - VBAT -----------------------------------------------------------------------------------------efficiency inductance frequency efficiency = 0.80 inductance = 0.68 H frequency = 2.4 MHz 176 Rev. 1.0 Si106x/108x 15.2. High Power Applications The dc-dc converter is designed to provide the system with 65 mW of output power, however, it can safely provide up to 100 mW of output power without any risk of damage to the device. For high power applications, the system should be carefully designed to prevent unwanted VBAT and VDD_MCU/DC+ Supply Monitor resets, which are more likely to occur when the dc-dc converter output power exceeds 65mW. In addition, output power above 65 mW causes the dc-dc converter to have relaxed output regulation, high output ripple and more analog noise. At high output power, an inductor with low DC resistance should be chosen in order to minimize power loss and maximize efficiency. The combination of high output power and low input voltage will result in very high peak and average inductor currents. If the power supply has a high internal resistance, the transient voltage on the VBAT terminal could drop below 0.9 V and trigger a VBAT Supply Monitor Reset, even if the open-circuit voltage is well above the 0.9 V threshold. While this problem is most often associated with operation from very small batteries or batteries that are near the end of their useful life, it can also occur when using bench power supplies that have a slow transient response; the supply's display may indicate a voltage above 0.9 V, but the minimum voltage on the VBAT pin may be lower. A similar problem can occur at the output of the dc-dc converter: using the default low current limit setting (125 mA) can trigger VDD Supply Monitor resets if there is a high transient load current, particularly if the programmed output voltage is at or near 1.8 V. 15.3. Pulse Skipping Mode The dc-dc converter allows the user to set the minimum pulse width such that if the duty cycle needs to decrease below a certain width in order to maintain regulation, an entire "clock pulse" will be skipped. Pulse skipping can provide substantial power savings, particularly at low values of load current. The converter will continue to maintain a minimum output voltage at its programmed value when pulse skipping is employed, though the output voltage ripple can be higher. Another consideration is that the dc-dc will operate with pulse-frequency modulation rather than pulse-width modulation, which makes the switching frequency spectrum less predictable; this could be an issue if the dc-dc converter is used to power a radio. Figure 4.5 and Figure 4.6 on page 50 and page 51 show the effect of pulse skipping on power consumption. 15.4. Enabling the DC-DC Converter On power-on reset, the state of the DCEN pin is sampled to determine if the device will power up in onecell or two-cell mode. In two-cell mode, the dc-dc converter always remains disabled. In one-cell mode, the dc-dc converter remains disabled in Sleep Mode, and enabled in all other power modes. See Section "13. Power Management" on page 160 for complete details on available power modes. The dc-dc converter is enabled (one-cell mode) in hardware by placing a 0.68 H inductor between DCEN and VBAT. The dc-dc converter is disabled (two-cell mode) by shorting DCEN directly to GND. The DCEN pin should never be left floating. Note that the device can only switch between one-cell and two-cell mode during a power-on reset. See Section "17. Reset Sources" on page 185 for more information regarding reset behavior. Figure 15.2 shows the two dc-dc converter configuration options. Rev. 1.0 177 Si106x/108x 0.68 uH DC-DC Converter Enabled 0.9 to 1.8 V Supply Voltage VBAT GND/VBAT- DCEN (one-cell mode) DC-DC Converter Disabled 1 uF 4.7 uF VBAT GND/VBAT- DCEN 1.8 to 3.6 V Supply Voltage GND_MCU/ VDD_MCU/ DCDC+ GND_MCU/ DCVDD_MCU/ DC+ (two-cell mode) Figure 15.2. DC-DC Converter Configuration Options When the dc-dc converter "Enabled" configuration (one-cell mode) is chosen, the following guidelines apply: In most cases, the GND/VBAT- pin should not be externally connected to GND. The 0.68 H inductor should be placed as close as possible to the DCEN pin for maximum efficiency. The 4.7 F capacitor should be placed as close as possible to the inductor. The current loop including GND/VBAT-, the 4.7 F capacitor, the 0.68 H inductor and the DCEN pin should be made as short as possible to minimize capacitance. The PCB traces connecting VDD_MCU/DC+ to the output capacitor and the output capacitor to GND_MCU/DC- should be as short and as thick as possible in order to minimize parasitic inductance. 178 Rev. 1.0 Si106x/108x 15.5. Minimizing Power Supply Noise To minimize noise on the power supply lines, the GND/VBAT- and GND_MCU/DC- pins should be kept separate, as shown in Figure 15.2; GND_MCU/DC- should be connected to the pc board ground plane. The large decoupling capacitors in the input and output circuits ensure that each supply is relatively quiet with respect to its own ground. However, connecting a circuit element "diagonally" (e.g., connecting an external device between VDD_MCU/DC+ and GND/VBAT-, or between VBAT and GND_MCU/DC-) can result in high supply noise across that circuit element. To accommodate situations in which ADC0 is sampling a signal that is referenced to one of the external grounds, we recommend using the Analog Ground Reference (P0.1/AGND) option described in Section 5.12. This option prevents any voltage differences between the internal chip ground and the external grounds from modulating the ADC input signal. If this option is enabled, the P0.1 pin should be tied to the ground reference of the external analog input signal. When using the ADC with the dc-dc converter, we also recommend enabling the SYNC bit in the DC0CN register to minimize interference. These general guidelines provide the best performance in most applications, though some situations may benefit from experimentation to eliminate any residual noise issues. Examples might include tying the grounds together, using additional low-inductance decoupling caps in parallel with the recommended ones, investigating the effects of different dc-dc converter settings, etc. 15.6. Selecting the Optimum Switch Size The dc-dc converter has two built-in switches (the diode bypass switch and duty cycle control switch). To maximize efficiency, one of two switch sizes may be selected. The large switches are ideal for carrying high currents and the small switches are ideal for low current applications. The ideal switchover point to switch from the small switches to the large switches varies with the programmed output voltage. At an output voltage of 2 V, the ideal switchover point is at approximately 4 mA total output current. At an output voltage of 3 V, the ideal switchover point is at approximately 8 mA total output current. 15.7. DC-DC Converter Clocking Options The dc-dc converter may be clocked from its internal oscillator, or from any system clock source, selectable by the CLKSEL bit (DC0CF.0). The dc-dc converter internal oscillator frequency is approximately 2.4 MHz. For a more accurate clock source, the system clock, or a divided version of the system clock may be used as the dc-dc clock source. The dc-dc converter has a built in clock divider (configured using DC0CF[6:5]) which allows any system clock frequency over 1.6 MHz to generate a valid clock in the range of 1.6 to 3.2 MHz. When the precision internal oscillator is selected as the system clock source, the OSCICL register may be used to fine tune the oscillator frequency and the dc-dc converter clock. The oscillator frequency should only be decreased since it is factory calibrated at its maximum frequency. The minimum frequency which can be reached by the oscillator after taking into account process variations is approximately 16 MHz. The system clock routed to the dc-dc converter clock divider also may be inverted by setting the CLKINV bit (DC0CF.3) to logic 1. These options can be used to minimize interference in noise sensitive applications. Rev. 1.0 179 Si106x/108x 15.8. DC-DC Converter Behavior in Sleep Mode When the Si106x/108x devices are placed in Sleep mode, the dc-dc converter is disabled, and the VDD_MCU/DC+ output is internally connected to VBAT by default. This behavior ensures that the GPIO pins are powered from a low-impedance source during sleep mode. If the GPIO pins are not used as inputs or outputs during sleep mode, then the VDD_MCU/DC+ output can be made to float during Sleep mode by setting the VDDSLP bit in the DC0CF register to 1. Setting this bit can provide power savings in two ways. First, if the sleep interval is relatively short and the VDD_MCU/DC+ load current (include leakage currents) is negligible, then the capacitor on VDD_MCU/DC+ will maintain the output voltage near the programmed value, which means that the VDD_MCU/DC+ capacitor will not need to be recharged upon every wake up event. The second power advantage is that internal or external low-power circuits that require more than 1.8 V can continue to function during Sleep mode without operating the dc-dc converter, powered by the energy stored in the 1 F output decoupling capacitor. For example, the comparators require about 0.4 A when operating in their lowest power mode. If the dc-dc converter output were increased to 3.3 V just before putting the device into Sleep mode, then the comparator could be powered for more than 3 seconds before the output voltage dropped to 1.8 V. In this example, the overall energy consumption would be much lower than if the dc-dc converter were kept running to power the comparator. If the load current on VDD_MCU/DC+ is high enough to discharge the VDD_MCU/DC+ capacitance to a voltage lower than VBAT during the sleep interval, an internal diode will prevent VDD_MCU/DC+ from dropping more than a few hundred millivolts below VBAT. There may be some additional leakage current from VBAT to ground when the VDD_MCU/DC+ level falls below VBAT, but this leakage current should be small compared to the current from VDD_MCU/DC+. The amount of time that it takes for a device configured in one-cell mode to wake up from Sleep mode depends on a number of factors, including the dc-dc converter clock speed, the settings of the SWSEL and ILIMIT bits, the battery internal resistance, the load current, and the difference between the VBAT voltage level and the programmed output voltage. The wake up time can be as short as 2 s, though it is more commonly in the range of 5 to 10 s, and it can exceed 50 s under extreme conditions. See Section "13. Power Management" on page 160 for more information about sleep mode. 180 Rev. 1.0 Si106x/108x 15.9. DC-DC Converter Register Descriptions The SFRs used to configure the dc-dc converter are described in the following register descriptions. The reset values for these registers can be used as-is in most systems; therefore, no software intervention or initialization is required. SFR Definition 15.1. DC0CN: DC-DC Converter Control Bit 7 6 5 4 3 2 1 Name MINPW SWSEL Reserved SYNC VSEL Type R/W R/W R/W R/W R/W 1 0 0 Reset 0 0 SFR Page = 0x0; SFR Address = 0x97 Bit Name 7:6 0 0 0 1 Function MINPW[1:0] DC-DC Converter Minimum Pulse Width. Specifies the minimum pulse width. 00: No minimum duty cycle. 01: Minimum pulse width is 20 ns. 10: Minimum pulse width is 40 ns. 11: Minimum pulse width is 80 ns. 5 SWSEL DC-DC Converter Switch Select. Selects one of two possible converter switch sizes to maximize efficiency. 0: The large switches are selected (best efficiency for high output currents). 1: The small switches are selected (best efficiency for low output currents). 4 Reserved 3 SYNC Always Write to 0. ADC0 Synchronization Enable. When synchronization is enabled, the ADC0SC[4:0] bits in the ADC0CF register must be set to 00000b. Behavior as described is valid in REVC and later devices. 0: The ADC is not synchronized to the dc-dc converter. 1: The ADC is synchronized to the dc-dc converter. ADC0 tracking is performed during the longest quiet time of the dc-dc converter switching cycle and ADC0 SAR clock is also synchronized to the dc-dc converter switching cycle. 2:0 VSEL[2:0] DC-DC Converter Output Voltage Select. Specifies the target output voltage. 000: Target output voltage is 1.8 V. 001: Target output voltage is 1.9 V. 010: Target output voltage is 2.0 V. 011: Target output voltage is 2.1 V. 100: Target output voltage is 2.4 V. 101: Target output voltage is 2.7 V. 110: Target output voltage is 3.0 V. 111: Target output voltage is 3.3 V. Rev. 1.0 181 Si106x/108x SFR Definition 15.2. DC0CF: DC-DC Converter Configuration Bit 7 6 Name Reserved Type R R/W Reset 0 0 5 4 3 2 1 0 AD0CKINV CLKINV ILIMIT VDDSLP CLKSEL R/W R/W R/W R/W R/W R/W 0 0 0 0 0 0 CLKDIV[1:0] SFR Page = 0x0; SFR Address = 0x96 Bit Name 7 6:5 Reserved Function Read = 0b; Must write 0b. CLKDIV[1:0] DC-DC Clock Divider. Divides the dc-dc converter clock when the system clock is selected as the clock source for dc-dc converter. These bits are ignored when the dc-dc converter is clocked from its local oscillator. 00: The dc-dc converter clock is system clock divided by 1. 01: The dc-dc converter clock is system clock divided by 2. 10: The dc-dc converter clock is system clock divided by 4. 11: The dc-dc converter clock is system clock divided by 8. 4 AD0CKINV ADC0 Clock Inversion (Clock Invert During Sync). Inverts the ADC0 SAR clock derived from the dc-dc converter clock when the SYNC bit (DC0CN.3) is enabled. This bit is ignored when the SYNC bit is set to zero. 0: ADC0 SAR clock is inverted. 1: ADC0 SAR clock is not inverted. 3 CLKINV DC-DC Converter Clock Invert. Inverts the system clock used as the input to the dc-dc clock divider. 0: The dc-dc converter clock is not inverted. 1: The dc-dc converter clock is inverted. 2 ILIMIT Peak Current Limit Threshold. Sets the threshold for the maximum allowed peak inductor current. See Table 15.1 for peak inductor current levels. 0: Peak inductor current is set at a lower level. 1: Peak inductor current is set at a higher level. 1 VDDSLP VDD_MCU/DC+ Sleep Mode Connection. Specifies the power source for VDD_MCU/DC+ in Sleep Mode when the dc-dc converter is enabled. 0: VDD_MCU/DC+ connected to VBAT in Sleep Mode. 1: VDD_MCU/DC+ is floating in Sleep Mode. 0 CLKSEL DC-DC Converter Clock Source Select. Specifies the dc-dc converter clock source. 0: The dc-dc converter is clocked from its local oscillator. 1: The dc-dc converter is clocked from the system clock. 182 Rev. 1.0 Si106x/108x 15.10. DC-DC Converter Specifications See Table 4.13 on page 65 for a detailed listing of dc-dc converter specifications. Rev. 1.0 183 Si106x/108x 16. Voltage Regulator (VREG0) Si106x/108x devices include an internal voltage regulator (VREG0) to regulate the internal core supply to 1.8 V from a VDD_MCU supply of 1.8 to 3.6 V. Electrical characteristics for the on-chip regulator are specified in the Electrical Specifications chapter. The REG0CN register allows the Precision Oscillator Bias to be disabled, saving approximately 80 A in all non-Sleep power modes. This bias should only be disabled when the precision oscillator is not being used. The internal regulator (VREG0) is disabled when the device enters Sleep Mode and remains enabled when the device enters Suspend Mode. See Section "13. Power Management" on page 160 for complete details about low power modes. SFR Definition 16.1. REG0CN: Voltage Regulator Control Bit 7 Name 6 5 4 Reserved Reserved OSCBIAS 3 2 1 0 Reserved Type R R/W R/W R/W R R R R/W Reset 0 0 0 1 0 0 0 0 SFR Page = 0x0; SFR Address = 0xC9 Bit Name 7 Unused Function Read = 0b. Write = Don't care. 6:5 Reserved Read = 0b. Must Write 0b. 4 OSCBIAS Precision Oscillator Bias. When set to 1, the bias used by the precision oscillator is forced on. If the precision oscillator is not being used, this bit may be cleared to 0 to save approximately 80 A of supply current in all non-Sleep power modes. If disabled then re-enabled, the precision oscillator bias requires 4 s of settling time. 3:1 0 Unused Read = 000b. Write = Don't care. Reserved Read = 0b. Must Write 0b. 16.1. Voltage Regulator Electrical Specifications See Table 4.14 on page 66 for detailed Voltage Regulator Electrical Specifications. Rev. 1.0 184 Si106x/108x 17. Reset Sources Reset circuitry allows the controller to be easily placed in a predefined default condition. On entry to this reset state, the following occur: CIP-51 halts program execution Special Function Registers (SFRs) are initialized to their defined reset values External Port pins are forced to a known state Interrupts and timers are disabled All SFRs are reset to the predefined values noted in the SFR descriptions. The contents of RAM are unaffected during a reset; any previously stored data is preserved as long as power is not lost. Since the stack pointer SFR is reset, the stack is effectively lost, even though the data on the stack is not altered. The Port I/O latches are reset to 0xFF (all logic ones) in open-drain mode. Weak pull-ups are enabled during and after the reset. For power-on resets, the RST pin is high-impedance with the weak pull-up off until the device exits the reset state. For VDD monitor resets, the RST pin is driven low until the device exits the reset state. On exit from the reset state, the program counter (PC) is reset, and the system clock defaults to an internal oscillator. Refer to Section "18. Clocking Sources" on page 192 for information on selecting and configuring the system clock source. The Watchdog Timer is enabled with the system clock divided by 12 as its clock source (Section "32.4. Watchdog Timer Mode" on page 344 details the use of the Watchdog Timer). Program execution begins at location 0x0000. VDD_MCU/DC+ + - (wired-OR) RST 0 Enable RTC0RE Missing Clock Detector (oneshot) EN Reset Funnel PCA WDT (Software Reset) SWRSF EN System Clock Illegal Flash Operation WDT Enable SmaRTClock + - C0RSEF MCD Enable Px.x Power On Reset Supply Monitor Comparator 0 Px.x VBAT CIP-51 Microcontroller Core System Reset System Reset Power Management Block (PMU0) Power-On Reset Reset Extended Interrupt Handler Figure 17.1. Reset Sources Rev. 1.0 185 Si106x/108x 17.1. MCU Power-On (VBAT Supply Monitor) Reset During power-up, the device is held in a reset state and the RST pin is driven low until VBAT settles above VPOR. An additional delay occurs before the device is released from reset; the delay decreases as the VBAT ramp time increases (VBAT ramp time is defined as how fast VBAT ramps from 0 V to VPOR). Figure 17.3 plots the power-on and VDD monitor reset timing. For valid ramp times (less than 3 ms), the power-on reset delay (TPORDelay) is typically 3 ms (VBAT = 0.9 V), 7 ms (VBAT = 1.8 V), or 15 ms (VBAT = 3.6 V). Note: The maximum VDD ramp time is 3 ms; slower ramp times may cause the device to be released from reset before VBAT reaches the VPOR level. volts On exit from a power-on reset, the PORSF flag (RSTSRC.1) is set by hardware to logic 1. When PORSF is set, all of the other reset flags in the RSTSRC Register are indeterminate (PORSF is cleared by all other resets). Since all resets cause program execution to begin at the same location (0x0000), software can read the PORSF flag to determine if a power-up was the cause of reset. The contents of internal data memory should be assumed to be undefined after a power-on reset. VBAT ~0.8 VPOR VB AT 0.6 ~0.5 See specification table for min/max voltages. t Logic HIGH Logic LOW RST TPORDelay Power-On Reset TPORDelay Power-On Reset Figure 17.2. Power-Fail Reset Timing Diagram 186 Rev. 1.0 Si106x/108x 17.2. Power-Fail (VDD_MCU Supply Monitor) Reset Si106x/108x devices have a VDD_MCU Supply Monitor that is enabled and selected as a reset source after each power-on or power-fail reset. When enabled and selected as a reset source, any power down transition or power irregularity that causes VDD_MCU to drop below VRST will cause the RST pin to be driven low and the CIP-51 will be held in a reset state (see Figure 17.3). When VDD_MCU returns to a level above VRST, the CIP-51 will be released from the reset state. After a power-fail reset, the PORSF flag reads 1, the contents of RAM invalid, and the VDD_MCU supply monitor is enabled and selected as a reset source. The enable state of the VDD_MCU supply monitor and its selection as a reset source is only altered by power-on and power-fail resets. For example, if the VDD_MCU supply monitor is de-selected as a reset source and disabled by software, then a software reset is performed, the VDD_MCU supply monitor will remain disabled and de-selected after the reset. In battery-operated systems, the contents of RAM can be preserved near the end of the battery's usable life if the device is placed in sleep mode prior to a power-fail reset occurring. When the device is in sleep mode, the power-fail reset is automatically disabled and the contents of RAM are preserved as long as the VBAT supply does not fall below VPOR. A large capacitor can be used to hold the power supply voltage above VPOR while the user is replacing the battery. Upon waking from sleep mode, the enable and reset source select state of the VDD_MCU supply monitor are restored to the value last set by the user. To allow software early notification that a power failure is about to occur, the VDDOK bit is cleared when the VDD_MCU supply falls below the VWARN threshold. The VDDOK bit can be configured to generate an interrupt. See Section "11. Interrupt Handler" on page 137 for more details. volts Important Note: To protect the integrity of Flash contents, the VDD_MCU supply monitor must be enabled and selected as a reset source if software contains routines which erase or write Flash memory. If the VDD_MCU supply monitor is not enabled, any erase or write performed on Flash memory will cause a Flash Error device reset. VDD_MCU/DC+ V WARN V RST VBAT V POR t VDDOK SLEEP RST Active M ode Pow er-Fail R eset Sleep M ode R AM Retained - No Reset N ote: W akeup signal required after new battery insertion Figure 17.3. Power-Fail Reset Timing Diagram Rev. 1.0 187 Si106x/108x Important Notes: The Power-on Reset (POR) delay is not incurred after a VDD_MCU supply monitor reset. See Section "4. Electrical Characteristics" on page 42 for complete electrical characteristics of the VDD_MCU monitor. Software should take care not to inadvertently disable the VDD Monitor as a reset source when writing to RSTSRC to enable other reset sources or to trigger a software reset. All writes to RSTSRC should explicitly set PORSF to '1' to keep the VDD Monitor enabled as a reset source. The VDD_MCU supply monitor must be enabled before selecting it as a reset source. Selecting the VDD_MCU supply monitor as a reset source before it has stabilized may generate a system reset. In systems where this reset would be undesirable, a delay should be introduced between enabling the VDD_MCU supply monitor and selecting it as a reset source. See Section "4. Electrical Characteristics" on page 42 for minimum VDD_MCU Supply Monitor turn-on time. No delay should be introduced in systems where software contains routines that erase or write Flash memory. The procedure for enabling the VDD_MCU supply monitor and selecting it as a reset source is shown below: 1. Enable the VDD_MCU Supply Monitor (VDMEN bit in VDM0CN = 1). 2. Wait for the VDD_MCU Supply Monitor to stabilize (optional). 3. Select the VDD_MCU Supply Monitor as a reset source (PORSF bit in RSTSRC = 1). 188 Rev. 1.0 Si106x/108x SFR Definition 17.1. VDM0CN: VDD_MCU Supply Monitor Control Bit 7 6 5 4 3 2 Name VDMEN VDDSTAT VDDOK Reserved Reserved Reserved Type R/W R R R/W R/W Reset 1 Varies Varies 0 0 SFR Page = 0x0; SFR Address = 0xFF Bit Name 7 VDMEN 1 0 R/W R/W R/W 0 0 0 Function VDD_MCU Supply Monitor Enable. This bit turns the VDD_MCU supply monitor circuit on/off. The VDD_MCU Supply Monitor cannot generate system resets until it is also selected as a reset source in register RSTSRC (SFR Definition 17.2). 0: VDD_MCU Supply Monitor Disabled. 1: VDD_MCU Supply Monitor Enabled. 6 VDDSTAT VDD_MCU Supply Status. This bit indicates the current power supply status. 0: VDD_MCU is at or below the VRST threshold. 1: VDD_MCU is above the VRST threshold. 5 VDDOK VDD_MCU Supply Status (Early Warning). This bit indicates the current power supply status. 0: VDD_MCU is at or below the VWARN threshold. 1: VDD_MCU is above the VWARN monitor threshold. 4:2 Reserved Read = 000b. Must Write 000b. 1:0 Unused Read = 00b. Write = Don't Care. 17.3. External Reset The external RST pin provides a means for external circuitry to force the device into a reset state. Asserting an active-low signal on the RST pin generates a reset; an external pullup and/or decoupling of the RST pin may be necessary to avoid erroneous noise-induced resets. See Table 4.4 for complete RST pin specifications. The external reset remains functional even when the device is in the low power Suspend and Sleep Modes. The PINRSF flag (RSTSRC.0) is set on exit from an external reset. 17.4. Missing Clock Detector Reset The Missing Clock Detector (MCD) is a one-shot circuit that is triggered by the system clock. If the system clock remains high or low for more than 100 s, the one-shot will time out and generate a reset. After a MCD reset, the MCDRSF flag (RSTSRC.2) will read 1, signifying the MCD as the reset source; otherwise, this bit reads 0. Writing a 1 to the MCDRSF bit enables the Missing Clock Detector; writing a 0 disables it. The missing clock detector reset is automatically disabled when the device is in the low power Suspend or Sleep mode. Upon exit from either low power state, the enabled/disabled state of this reset source is restored to its previous value. The state of the RST pin is unaffected by this reset. Rev. 1.0 189 Si106x/108x 17.5. Comparator0 Reset Comparator0 can be configured as a reset source by writing a 1 to the C0RSEF flag (RSTSRC.5). Comparator0 should be enabled and allowed to settle prior to writing to C0RSEF to prevent any turn-on chatter on the output from generating an unwanted reset. The Comparator0 reset is active-low: if the non-inverting input voltage (on CP0+) is less than the inverting input voltage (on CP0-), the device is put into the reset state. After a Comparator0 reset, the C0RSEF flag (RSTSRC.5) will read 1 signifying Comparator0 as the reset source; otherwise, this bit reads 0. The Comparator0 reset source remains functional even when the device is in the low power Suspend and Sleep states as long as Comparator0 is also enabled as a wakeup source. The state of the RST pin is unaffected by this reset. 17.6. PCA Watchdog Timer Reset The programmable Watchdog Timer (WDT) function of the Programmable Counter Array (PCA) can be used to prevent software from running out of control during a system malfunction. The PCA WDT function can be enabled or disabled by software as described in Section "32.4. Watchdog Timer Mode" on page 344; the WDT is enabled and clocked by SYSCLK / 12 following any reset. If a system malfunction prevents user software from updating the WDT, a reset is generated and the WDTRSF bit (RSTSRC.5) is set to 1. The PCA Watchdog Timer reset source is automatically disabled when the device is in the low power Suspend or Sleep mode. Upon exit from either low power state, the enabled/disabled state of this reset source is restored to its previous value.The state of the RST pin is unaffected by this reset. 17.7. Flash Error Reset If a Flash read/write/erase or program read targets an illegal address, a system reset is generated. This may occur due to any of the following: A Flash write or erase is attempted above user code space. This occurs when PSWE is set to 1 and a MOVX write operation targets an address above the Lock Byte address. A Flash read is attempted above user code space. This occurs when a MOVC operation targets an address above the Lock Byte address. A Program read is attempted above user code space. This occurs when user code attempts to branch to an address above the Lock Byte address. A Flash read, write or erase attempt is restricted due to a Flash security setting (see Section "12.3. Security Options" on page 151). A Flash write or erase is attempted while the VDD Monitor is disabled. The FERROR bit (RSTSRC.6) is set following a Flash error reset. The state of the RST pin is unaffected by this reset. 17.8. SmaRTClock (Real Time Clock) Reset The SmaRTClock can generate a system reset on two events: SmaRTClock Oscillator Fail or SmaRTClock Alarm. The SmaRTClock Oscillator Fail event occurs when the SmaRTClock Missing Clock Detector is enabled and the SmaRTClock clock is below approximately 20 kHz. A SmaRTClock alarm event occurs when the SmaRTClock Alarm is enabled and the SmaRTClock timer value matches the ALARMn registers. The SmaRTClock can be configured as a reset source by writing a 1 to the RTC0RE flag (RSTSRC.7). The SmaRTClock reset remains functional even when the device is in the low power Suspend or Sleep mode. The state of the RST pin is unaffected by this reset. 17.9. Software Reset Software may force a reset by writing a 1 to the SWRSF bit (RSTSRC.4). The SWRSF bit will read 1 following a software forced reset. The state of the RST pin is unaffected by this reset. 190 Rev. 1.0 Si106x/108x SFR Definition 17.2. RSTSRC: Reset Source Bit 7 6 5 4 3 2 1 0 Name RTC0RE FERROR C0RSEF SWRSF WDTRSF MCDRSF PORSF PINRSF Type R/W R R/W R/W R R/W R/W R Reset Varies Varies Varies Varies Varies Varies Varies Varies SFR Page = 0x0; SFR Address = 0xEF. Bit Name Description Write Read 7 RTC0RE SmaRTClock Reset Enable and Flag 0: Disable SmaRTClock Set to 1 if SmaRTClock as a reset source. alarm or oscillator fail 1: Enable SmaRTClock as caused the last reset. a reset source. 6 FERROR Flash Error Reset Flag. N/A 5 C0RSEF Comparator0 Reset Enable and Flag. 0: Disable Comparator0 as Set to 1 if Comparator0 a reset source. caused the last reset. 1: Enable Comparator0 as a reset source. 4 SWRSF Writing a 1 forces a system reset. Software Reset Force and Flag. 3 WDTRSF Watchdog Timer Reset Flag. N/A 2 MCDRSF Missing Clock Detector (MCD) Enable and Flag. Set to 1 if Flash read/write/erase error caused the last reset. Set to 1 if last reset was caused by a write to SWRSF. Set to 1 if Watchdog Timer overflow caused the last reset. 0: Disable the MCD. Set to 1 if Missing Clock Detector timeout caused 1: Enable the MCD. The MCD triggers a reset the last reset. if a missing clock condition is detected. 1 PORSF Power-On / Power-Fail Reset Flag, and Power-Fail Reset Enable. 0: Disable the VDD_MCU Supply Monitor as a reset source. 1: Enable the VDD_MCU Supply Monitor as a reset source.3 Set to 1 anytime a poweron or VDD monitor reset occurs.2 0 PINRSF HW Pin Reset Flag. N/A Set to 1 if RST pin caused the last reset. Notes: 1. It is safe to use read-modify-write operations (ORL, ANL, etc.) to enable or disable specific interrupt sources. 2. If PORSF read back 1, the value read from all other bits in this register are indeterminate. 3. Writing a 1 to PORSF before the VDD_MCU Supply Monitor is stabilized may generate a system reset. Rev. 1.0 191 Si106x/108x 18. Clocking Sources Si106x/108x devices include a programmable precision internal oscillator, an external oscillator drive circuit, a low power internal oscillator, and a SmaRTClock real time clock oscillator. The precision internal oscillator can be enabled/disabled and calibrated using the OSCICN and OSCICL registers, as shown in Figure 18.1. The external oscillator can be configured using the OSCXCN register. The low power internal oscillator is automatically enabled and disabled when selected and deselected as a clock source. SmaRTClock operation is described in the SmaRTClock oscillator chapter. The system clock (SYSCLK) can be derived from the precision internal oscillator, external oscillator, low power internal oscillator, or SmaRTClock oscillator. The global clock divider can generate a system clock that is 1, 2, 4, 8, 16, 32, 64, or 128 times slower that the selected input clock source. Oscillator electrical specifications can be found in the Electrical Specifications Chapter. OSCICL OSCICN CLKSEL VDD XTAL2 CLKSL1 CLKSL0 CLKRDY CLKDIV2 CLKDIV1 CLKDIV0 Option 3 IOSCEN IFRDY Option 2 XTAL2 EN Precision Internal Oscillator Option 1 Precision Internal Oscillator XTAL1 External Oscillator External Oscillator Drive Circuit 10M CLKRDY Low Power Internal Oscillator XTAL2 n SYSCLK Clock Divider smaRTClock Oscillator Option 4 XFCN2 XFCN1 XFCN0 XTLVLD XOSCMD2 XOSCMD1 XOSCMD0 XTAL2 Low Power Internal Oscillator smaRTClock Oscillator OSCXCN Figure 18.1. Clocking Sources Block Diagram The proper way of changing the system clock when both the clock source and the clock divide value are being changed is as follows: If switching from a fast "undivided" clock to a slower "undivided" clock: 1. Change the clock divide value. 2. Poll for CLKRDY > 1. 3. Change the clock source. If switching from a slow "undivided" clock to a faster "undivided" clock: 1. Change the clock source. 2. Change the clock divide value. 3. Poll for CLKRDY > 1. Rev. 1.0 192 Si106x/108x 18.1. Programmable Precision Internal Oscillator All Si106x/108x devices include a programmable precision internal oscillator that may be selected as the system clock. OSCICL is factory calibrated to obtain a 24.5 MHz frequency. See Table 4.7, "Internal Precision Oscillator Electrical Characteristics," on page 59 for complete oscillator specifications. The precision oscillator supports a spread spectrum mode which modulates the output frequency in order to reduce the EMI generated by the system. When enabled (SSE = 1), the oscillator output frequency is modulated by a stepped triangle wave whose frequency is equal to the oscillator frequency divided by 384 (63.8 kHz using the factory calibration). The deviation from the nominal oscillator frequency is +0%, -1.6%, and the step size is typically 0.26% of the nominal frequency. When using this mode, the typical average oscillator frequency is lowered from 24.5 MHz to 24.3 MHz. 18.2. Low Power Internal Oscillator All Si106x/108x devices include a low power internal oscillator that defaults as the system clock after a system reset. The low power internal oscillator frequency is 20 MHz 10% and is automatically enabled when selected as the system clock and disabled when not in use. See Table 4.8, "Internal Low-Power Oscillator Electrical Characteristics," on page 59 for complete oscillator specifications. 18.3. External Oscillator Drive Circuit All Si106x/108x devices include an external oscillator circuit that may drive an external crystal, ceramic resonator, capacitor, or RC network. A CMOS clock may also provide a clock input. Figure 18.1 shows a block diagram of the four external oscillator options. The external oscillator is enabled and configured using the OSCXCN register. The external oscillator output may be selected as the system clock or used to clock some of the digital peripherals (e.g., Timers, PCA, etc.). See the data sheet chapters for each digital peripheral for details. See Section "4. Electrical Characteristics" on page 42 for complete oscillator specifications. 18.3.1. External Crystal Mode If a crystal or ceramic resonator is used as the external oscillator, the crystal/resonator and a 10 Mresistor must be wired across the XTAL1 and XTAL2 pins as shown in Figure 18.1, Option 1. Appropriate loading capacitors should be added to XTAL1 and XTAL2, and both pins should be configured for analog I/O with the digital output drivers disabled. Figure 18.2 shows the external oscillator circuit for a 20 MHz quartz crystal with a manufacturer recommended load capacitance of 12.5 pF. Loading capacitors are "in series" as seen by the crystal and "in parallel" with the stray capacitance of the XTAL1 and XTAL2 pins. The total value of the each loading capacitor and the stray capacitance of each XTAL pin should equal 12.5pF x 2 = 25 pF. With a stray capacitance of 10 pF per pin, the 15 pF capacitors yield an equivalent series capacitance of 12.5 pF across the crystal. Note: The recommended load capacitance depends upon the crystal and the manufacturer. Please refer to the crystal data sheet when completing these calculations. 193 Rev. 1.0 Si106x/108x 15 pF XTAL1 10 M 25 MHz XTAL2 15 pF Figure 18.2. 25 MHz External Crystal Example Important Note on External Crystals: Crystal oscillator circuits are quite sensitive to PCB layout. The crystal should be placed as close as possible to the XTAL pins on the device. The traces should be as short as possible and shielded with ground plane from any other traces which could introduce noise or interference. When using an external crystal, the external oscillator drive circuit must be configured by software for Crystal Oscillator Mode or Crystal Oscillator Mode with divide by 2 stage. The divide by 2 stage ensures that the clock derived from the external oscillator has a duty cycle of 50%. The External Oscillator Frequency Control value (XFCN) must also be specified based on the crystal frequency. The selection should be based on Table 18.1. For example, a 25 MHz crystal requires an XFCN setting of 111b. Table 18.1. Recommended XFCN Settings for Crystal Mode XFCN Crystal Frequency Bias Current Typical Supply Current (VDD = 2.4 V) 000 f 20 kHz 0.5 A 3.0 A, f = 32.768 kHz 001 20 kHz f 58 kHz 1.5 A 4.8 A, f = 32.768 kHz 010 58 kHz f 155 kHz 4.8 A 9.6 A, f = 32.768 kHz 011 155 kHz f 415 kHz 14 A 28 A, f = 400 kHz 100 415 kHz f 1.1 MHz 40 A 71 A, f = 400 kHz 101 1.1 MHz f 3.1 MHz 120 A 193 A, f = 400 kHz 110 3.1 MHz f 8.2 MHz 550 A 940 A, f = 8 MHz 111 8.2 MHz f 25 MHz 2.6 mA 3.9 mA, f = 25 MHz When the crystal oscillator is first enabled, the external oscillator valid detector allows software to determine when the external system clock has stabilized. Switching to the external oscillator before the crystal oscillator has stabilized can result in unpredictable behavior. The recommended procedure for starting the crystal is: 1. Configure XTAL1 and XTAL2 for analog I/O and disable the digital output drivers. 2. Configure and enable the external oscillator. 3. Poll for XTLVLD => 1. 4. Switch the system clock to the external oscillator. Rev. 1.0 194 Si106x/108x 18.3.2. External RC Mode If an RC network is used as the external oscillator, the circuit should be configured as shown in Figure 18.1, Option 2. The RC network should be added to XTAL2, and XTAL2 should be configured for analog I/O with the digital output drivers disabled. XTAL1 is not affected in RC mode. The capacitor should be no greater than 100 pF; however for very small capacitors, the total capacitance may be dominated by parasitic capacitance in the PCB layout. The resistor should be no smaller than 10k. The oscillation frequency can be determined by the following equation: 3 1.23 10 f = ------------------------RC where f = frequency of clock in MHzR = pull-up resistor value in k VDD = power supply voltage in VoltsC = capacitor value on the XTAL2 pin in pF To determine the required External Oscillator Frequency Control value (XFCN) in the OSCXCN Register, first select the RC network value to produce the desired frequency of oscillation. For example, if the frequency desired is 100 kHz, let R = 246 k and C = 50 pF: 3 3 1.23 10 1.23 10 f = ------------------------- = ------------------------- = 100 kHz RC 246 50 where f = frequency of clock in MHz; R = pull-up resistor value in k VDD = power supply voltage in Volts; C = capacitor value on the XTAL2 pin in pF Referencing Table 18.2, the recommended XFCN setting is 010. Table 18.2. Recommended XFCN Settings for RC and C modes XFCN Approximate Frequency Range (RC and C Mode) K Factor (C Mode) Typical Supply Current/ Actual Measured Frequency (C Mode, VDD = 2.4 V) 000 f 25 kHz K Factor = 0.87 3.0 A, f = 11 kHz, C = 33 pF 001 25 kHz f 50 kHz K Factor = 2.6 5.5 A, f = 33 kHz, C = 33 pF 010 50 kHz f 100 kHz K Factor = 7.7 13 A, f = 98 kHz, C = 33 pF 011 100 kHz f 200 kHz K Factor = 22 32 A, f = 270 kHz, C = 33 pF 100 200 kHz f 400 kHz K Factor = 65 82 A, f = 310 kHz, C = 46 pF 101 400 kHz f 800 kHz K Factor = 180 242 A, f = 890 kHz, C = 46 pF 110 800 kHz f 1.6 MHz K Factor = 664 1.0 mA, f = 2.0 MHz, C = 46 pF 111 1.6 MHz f 3.2 MHz K Factor = 1590 4.6 mA, f = 6.8 MHz, C = 46 pF When the RC oscillator is first enabled, the external oscillator valid detector allows software to determine when oscillation has stabilized. The recommended procedure for starting the RC oscillator is: 1. Configure XTAL2 for analog I/O and disable the digital output drivers. 2. Configure and enable the external oscillator. 195 Rev. 1.0 Si106x/108x 3. Poll for XTLVLD > 1. 4. Switch the system clock to the external oscillator. 18.3.3. External Capacitor Mode If a capacitor is used as the external oscillator, the circuit should be configured as shown in Figure 18.1, Option 3. The capacitor should be added to XTAL2, and XTAL2 should be configured for analog I/O with the digital output drivers disabled. XTAL1 is not affected in RC mode. The capacitor should be no greater than 100 pF; however, for very small capacitors, the total capacitance may be dominated by parasitic capacitance in the PCB layout. The oscillation frequency and the required External Oscillator Frequency Control value (XFCN) in the OSCXCN Register can be determined by the following equation: KF f = --------------------C V DD where f = frequency of clock in MHzR = pull-up resistor value in k VDD = power supply voltage in VoltsC = capacitor value on the XTAL2 pin in pF Below is an example of selecting the capacitor and finding the frequency of oscillation Assume VDD = 3.0 V and f = 150 kHz: KF f = --------------------C V DD KF 0.150 MHz = ----------------C 3.0 Since a frequency of roughly 150 kHz is desired, select the K Factor from Table 18.2 as KF = 22: 22 0.150 MHz = ----------------------C 3.0 V 22 C = ----------------------------------------------0.150 MHz 3.0 V C = 48.8 pF Therefore, the XFCN value to use in this example is 011 and C is approximately 50 pF. The recommended startup procedure for C mode is the same as RC mode. 18.3.4. External CMOS Clock Mode If an external CMOS clock is used as the external oscillator, the clock should be directly routed into XTAL2. The XTAL2 pin should be configured as a digital input. XTAL1 is not used in external CMOS clock mode. The external oscillator valid detector will always return zero when the external oscillator is configured to External CMOS Clock mode. Rev. 1.0 196 Si106x/108x 18.4. Special Function Registers for Selecting and Configuring the System Clock The clocking sources on Si106x/108x devices are enabled and configured using the OSCICN, OSCICL, OSCXCN and the SmaRTClock internal registers. See Section "19. SmaRTClock (Real Time Clock)" on page 200 for SmaRTClock register descriptions. The system clock source for the MCU can be selected using the CLKSEL register. To minimize active mode current, the oneshot timer which sets Flash read time should by bypassed when the system clock is greater than 10 MHz. See the FLSCL register description for details. The clock selected as the system clock can be divided by 1, 2, 4, 8, 16, 32, 64, or 128. When switching between two clock divide values, the transition may take up to 128 cycles of the undivided clock source. The CLKRDY flag can be polled to determine when the new clock divide value has been applied. The clock divider must be set to "divide by 1" when entering Suspend or Sleep Mode. The system clock source may also be switched on-the-fly. The switchover takes effect after one clock period of the slower oscillator. SFR Definition 18.1. CLKSEL: Clock Select Bit 7 6 5 4 3 2 Name CLKRDY Type R R/W R/W R/W R/W R/W R/W R/W Reset 0 0 1 1 0 1 0 0 CLKDIV[2:0] 1 0 CLKSEL[2:0] SFR Page = All Pages; SFR Address = 0xA9 Bit Name 7 CLKRDY 6:4 3 2:0 197 CLKDIV[2:0] Unused CLKSEL[2:0] Function System Clock Divider Clock Ready Flag. 0: The selected clock divide setting has not been applied to the system clock. 1: The selected clock divide setting has been applied to the system clock. System Clock Divider Bits. Selects the clock division to be applied to the undivided system clock source. 000: System clock is divided by 1. 001: System clock is divided by 2. 010: System clock is divided by 4. 011: System clock is divided by 8. 100: System clock is divided by 16. 101: System clock is divided by 32. 110: System clock is divided by 64. 111: System clock is divided by 128. Read = 0b. Must Write 0b. System Clock Select. Selects the oscillator to be used as the undivided system clock source. 000: Precision Internal Oscillator. 001: External Oscillator. 010: Reserved. 011: SmaRTClock Oscillator. 1xx: Low Power Oscillator. Rev. 1.0 Si106x/108x SFR Definition 18.2. OSCICN: Internal Oscillator Control Bit 7 6 5 4 3 Name IOSCEN IFRDY Type R/W R R/W R/W R/W Reset 0 0 0 0 1 2 1 0 R/W R/W R/W 1 1 1 Reserved[5:0] SFR Page = 0x0; SFR Address = 0xB2 Bit Name 7 IOSCEN Function Internal Oscillator Enable. 0: Internal oscillator disabled. 1: Internal oscillator enabled. 6 5:0 IFRDY Internal Oscillator Frequency Ready Flag. 0: Internal oscillator is not running at its programmed frequency. 1: Internal oscillator is running at its programmed frequency. Reserved Reserved. Si106x--Read=001111b. Must write 001111b. Si108x--Must perform read-modify-write. Note: It is recommended to use read-modify-write operations such as ORL and ANL to set or clear the enable bit of this register. SFR Definition 18.3. OSCICL: Internal Oscillator Calibration Bit 7 6 5 4 Name SSE Type R/W R R/W R/W Reset 0 Varies Varies Varies 3 2 1 0 R/W R/W R/W R/W Varies Varies Varies Varies OSCICL[6:0] SFR Page = 0x0; SFR Address = 0xB3 Bit Name 7 SSE 6:0 OSCICL Function Spread Spectrum Enable. 0: Spread Spectrum clock dithering disabled. 1: Spread Spectrum clock dithering enabled. Internal Oscillator Calibration. Factory calibrated to obtain a frequency of 24.5 MHz. Incrementing this register decreases the oscillator frequency and decrementing this register increases the oscillator frequency. The step size is approximately 1% of the calibrated frequency. The recommended calibration frequency range is between 16 and 24.5 MHz. Note: If the Precision Internal Oscillator is selected as the system clock, the following procedure should be used when changing the value of the internal oscillator calibration bits. 1. Switch to a different clock source. 2. Disable the oscillator by writing OSCICN.7 to 0. Rev. 1.0 198 Si106x/108x 3. Change OSCICL to the desired setting. 4. Enable the oscillator by writing OSCICN.7 to 1. SFR Definition 18.4. OSCXCN: External Oscillator Control Bit 7 6 Name XCLKVLD 5 4 XOSCMD[2:0] 3 2 Reserved 1 0 XFCN[2:0] Type R R R/W R/W R/W R/W R/W R/W Reset 0 0 0 0 0 0 0 0 SFR Page = 0x0; SFR Address = 0xB1 Bit 7 Name Function XCLKVLD External Oscillator Valid Flag. Provides External Oscillator status and is valid at all times for all modes of operation except External CMOS Clock Mode and External CMOS Clock Mode with divide by 2. In these modes, XCLKVLD always returns 0. 0: External Oscillator is unused or not yet stable. 1: External Oscillator is running and stable. 6:4 XOSCMD External Oscillator Mode Bits. Configures the external oscillator circuit to the selected mode. 00x: External Oscillator circuit disabled. 010: External CMOS Clock Mode. 011: External CMOS Clock Mode with divide by 2 stage. 100: RC Oscillator Mode. 101: Capacitor Oscillator Mode. 110: Crystal Oscillator Mode. 111: Crystal Oscillator Mode with divide by 2 stage. 3 2:0 Reserved Read = 0b. Must Write 0b. XFCN External Oscillator Frequency Control Bits. Controls the external oscillator bias current. 000-111: See Table 18.1 on page 194 (Crystal Mode) or Table 18.2 on page 195 (RC or C Mode) for recommended settings. 199 Rev. 1.0 Si106x/108x 19. SmaRTClock (Real Time Clock) Si106x/108x devices include an ultra low power 32-bit SmaRTClock Peripheral (Real Time Clock) with alarm. The SmaRTClock has a dedicated 32 kHz oscillator that can be configured for use with or without a crystal. No external resistor or loading capacitors are required. The on-chip loading capacitors are programmable to 16 discrete levels allowing compatibility with a wide range of crystals. The SmaRTClock can operate directly from a 0.9-3.6 V battery voltage and remains operational even when the device goes into its lowest power down mode. The SmaRTClock allows a maximum of 36 hour 32-bit independent time-keeping when used with a 32.768 kHz Watch Crystal. The SmaRTClock provides an Alarm and Missing SmaRTClock events, which could be used as reset or wakeup sources. See Section "17. Reset Sources" on page 185 and Section "13. Power Management" on page 160 for details on reset sources and low power mode wake-up sources, respectively. XTAL3 XTAL4 SmaRTClock Power/ Clock Mgmt Programmable Load Capacitors SmaRTClock Oscillator CIP-51 CPU 32-Bit SmaRTClock Timer SmaRTClock State Machine Wake-Up Interrupt Internal Registers CAPTUREn RTC0CN RTC0XCN RTC0XCF RTC0PIN ALARMn Interface Registers RTC0KEY RTC0ADR RTC0DAT Figure 19.1. SmaRTClock Block Diagram 19.1. SmaRTClock Interface The SmaRTClock Interface consists of three registers: RTC0KEY, RTC0ADR, and RTC0DAT. These interface registers are located on the CIP-51's SFR map and provide access to the SmaRTClock internal registers listed in Table 19.1. The SmaRTClock internal registers can only be accessed indirectly through the SmaRTClock Interface Rev. 1.0 200 Si106x/108x . Table 19.1. SmaRTClock Internal Registers SmaRTClock SmaRTClock Address Register Register Name Description 0x00-0x03 CAPTUREn SmaRTClock Capture Registers Four Registers used for setting the 32-bit SmaRTClock timer or reading its current value. 0x04 RTC0CN SmaRTClock Control Register Controls the operation of the SmaRTClock State Machine. 0x05 RTC0XCN SmaRTClock Oscillator Control Register Controls the operation of the SmaRTClock Oscillator. 0x06 RTC0XCF SmaRTClock Oscillator Configuration Register Controls the value of the progammable oscillator load capacitance and enables/disables AutoStep. 0x07 RTC0PIN SmaRTClock Pin Configuration Register Note: Forces XTAL3 and XTAL4 to be internally shorted. This register also contains other reserved bits which should not be modified. 0x08-0x0B ALARMn SmaRTClock Alarm Registers Four registers used for setting or reading the 32-bit SmaRTClock alarm value. 19.1.1. SmaRTClock Lock and Key Functions The SmaRTClock Interface is protected with a lock and key function. The SmaRTClock Lock and Key Register (RTC0KEY) must be written with the correct key codes, in sequence, before writes and reads to RTC0ADR and RTC0DAT may be performed. The key codes are: 0xA5, 0xF1. There are no timing restrictions, but the key codes must be written in order. If the key codes are written out of order, the wrong codes are written, or an indirect register read or write is attempted while the interface is locked, the SmaRTClock interface will be disabled, and the RTC0ADR and RTC0DAT registers will become inaccessible until the next system reset. Once the SmaRTClock interface is unlocked, software may perform any number of accesses to the SmaRTClock registers until the interface is re-locked or the device is reset. Any write to RTC0KEY while the SmaRTClock interface is unlocked will re-lock the interface. Reading the RTC0KEY register at any time will provide the SmaRTClock Interface status and will not interfere with the sequence that is being written. The RTC0KEY register description in SFR Definition 19.1 lists the definition of each status code. 19.1.2. Using RTC0ADR and RTC0DAT to Access SmaRTClock Internal Registers The SmaRTClock internal registers can be read and written using RTC0ADR and RTC0DAT. The RTC0ADR register selects the SmaRTClock internal register that will be targeted by subsequent reads or writes. Recommended instruction timing is provided in this section. If the recommended instruction timing is not followed, then BUSY (RTC0ADR.7) should be checked prior to each read or write operation to make sure the SmaRTClock Interface is not busy performing the previous read or write operation. A SmaRTClock Write operation is initiated by writing to the RTC0DAT register. Below is an example of writing to a SmaRTClock internal register. 1. Poll BUSY (RTC0ADR.7) until it returns 0 or follow recommended instruction timing. 2. Write 0x05 to RTC0ADR. This selects the internal RTC0CN register at SmaRTClock Address 0x05. 3. Write 0x00 to RTC0DAT. This operation writes 0x00 to the internal RTC0CN register. A SmaRTClock Read operation is initiated by setting the SmaRTClock Interface Busy bit. This transfers the contents of the internal register selected by RTC0ADR to RTC0DAT. The transferred data will remain in 201 Rev. 1.0 Si106x/108x RTC0DAT until the next read or write operation. Below is an example of reading a SmaRTClock internal register. 1. Poll BUSY (RTC0ADR.7) until it returns 0 or follow recommended instruction timing. 2. Write 0x05 to RTC0ADR. This selects the internal RTC0CN register at SmaRTClock Address 0x05. 3. Write 1 to BUSY. This initiates the transfer of data from RTC0CN to RTC0DAT. 4. Poll BUSY (RTC0ADR.7) until it returns 0 or follow recommend instruction timing. 5. Read data from RTC0DAT. This data is a copy of the RTC0CN register. Note: The RTC0ADR and RTC0DAT registers will retain their state upon a device reset. 19.1.3. RTC0ADR Short Strobe Feature Reads and writes to indirect SmaRTClock registers normally take 7 system clock cycles. To minimize the indirect register access time, the Short Strobe feature decreases the read and write access time to 6 system clocks. The Short Strobe feature is automatically enabled on reset and can be manually enabled/disabled using the SHORT (RTC0ADR.4) control bit. Recommended Instruction Timing for a single register read with short strobe enabled: mov RTC0ADR, #095h nop nop nop mov A, RTC0DAT Recommended Instruction Timing for a single register write with short strobe enabled: mov RTC0ADR, #095h mov RTC0DAT, #000h nop 19.1.4. SmaRTClock Interface Autoread Feature When Autoread is enabled, each read from RTC0DAT initiates the next indirect read operation on the SmaRTClock internal register selected by RTC0ADR. Software should set the BUSY bit once at the beginning of each series of consecutive reads. Software should follow recommended instruction timing or check if the SmaRTClock Interface is busy prior to reading RTC0DAT. Autoread is enabled by setting AUTORD (RTC0ADR.6) to logic 1. 19.1.5. RTC0ADR Autoincrement Feature For ease of reading and writing the 32-bit CAPTURE and ALARM values, RTC0ADR automatically increments after each read or write to a CAPTUREn or ALARMn register. This speeds up the process of setting an alarm or reading the current SmaRTClock timer value. Autoincrement is always enabled. Recommended Instruction Timing for a multi-byte register read with short strobe and autoread enabled: mov nop nop nop mov nop nop mov nop nop mov RTC0ADR, #0d0h A, RTC0DAT A, RTC0DAT A, RTC0DAT Rev. 1.0 202 Si106x/108x nop nop mov A, RTC0DAT Recommended Instruction Timing for a multi-byte register write with short strobe enabled: mov mov nop mov nop mov nop mov nop 203 RTC0ADR, #010h RTC0DAT, #05h RTC0DAT, #06h RTC0DAT, #07h RTC0DAT, #08h Rev. 1.0 Si106x/108x SFR Definition 19.1. RTC0KEY: SmaRTClock Lock and Key Bit 7 6 5 4 3 Name RTC0ST[7:0] Type R/W Reset 0 0 0 0 SFR Page = 0x0; SFR Address = 0xAE Bit Name 7:0 RTC0ST 0 2 1 0 0 0 0 Function SmaRTClock Interface Lock/Key and Status. Locks/unlocks the SmaRTClock interface when written. Provides lock status when read. Read: 0x00: SmaRTClock Interface is locked. 0x01: SmaRTClock Interface is locked. First key code (0xA5) has been written, waiting for second key code. 0x02: SmaRTClock Interface is unlocked. First and second key codes (0xA5, 0xF1) have been written. 0x03: SmaRTClock Interface is disabled until the next system reset. Write: When RTC0ST = 0x00 (locked), writing 0xA5 followed by 0xF1 unlocks the SmaRTClock Interface. When RTC0ST = 0x01 (waiting for second key code), writing any value other than the second key code (0xF1) will change RTC0STATE to 0x03 and disable the SmaRTClock Interface until the next system reset. When RTC0ST = 0x02 (unlocked), any write to RTC0KEY will lock the SmaRTClock Interface. When RTC0ST = 0x03 (disabled), writes to RTC0KEY have no effect. Rev. 1.0 204 Si106x/108x SFR Definition 19.2. RTC0ADR: SmaRTClock Address Bit 7 6 Name BUSY AUTORD Type R/W R/W Reset 0 0 5 4 BUSY 2 SHORT ADDR[3:0] R R/W R/W 0 0 SFR Page = 0x0; SFR Address = 0xAC Bit Name 7 3 0 0 1 0 0 0 Function SmaRTClock Interface Busy Indicator. Indicates SmaRTClock interface status. Writing 1 to this bit initiates an indirect read. 6 AUTORD SmaRTClock Interface Autoread Enable. Enables/disables Autoread. 0: Autoread Disabled. 1: Autoread Enabled. 5 Unused Read = 0b; Write = Don't Care. 4 SHORT Short Strobe Enable. Enables/disables the Short Strobe Feature. 0: Short Strobe disabled. 1: Short Strobe enabled. 3:0 ADDR[3:0] SmaRTClock Indirect Register Address. Sets the currently selected SmaRTClock register. See Table 19.1 for a listing of all SmaRTClock indirect registers. Note: The ADDR bits increment after each indirect read/write operation that targets a CAPTUREn or ALARMn internal SmaRTClock register. 205 Rev. 1.0 Si106x/108x SFR Definition 19.3. RTC0DAT: SmaRTClock Data Bit 7 6 5 4 3 Name RTC0DAT[7:0] Type R/W Reset 0 0 0 0 SFR Page= 0x0; SFR Address = 0xAD Bit Name 7:0 0 2 1 0 0 0 0 Function RTC0DAT SmaRTClock Data Bits. Holds data transferred to/from the internal SmaRTClock register selected by RTC0ADR. Note: Read-modify-write instructions (orl, anl, etc.) should not be used on this register. Rev. 1.0 206 Si106x/108x 19.2. SmaRTClock Clocking Sources The SmaRTClock peripheral is clocked from its own timebase, independent of the system clock. The SmaRTClock timebase is derived from the SmaRTClock oscillator circuit, which has two modes of operation: Crystal Mode, and Self-Oscillate Mode. The oscillation frequency is 32.768 kHz in Crystal Mode and can be programmed in the range of 10 kHz to 40 kHz in Self-Oscillate Mode. The frequency of the SmaRTClock oscillator can be measured with respect to another oscillator using an on-chip timer. See Section "31. Timers" on page 311 for more information on how this can be accomplished. Note: The SmaRTClock timebase can be selected as the system clock and routed to a port pin. See Section "18. Clocking Sources" on page 192 for information on selecting the system clock source and Section "20. Si106x/108xPort Input/Output" on page 217 for information on how to route the system clock to a port pin. 19.2.1. Using the SmaRTClock Oscillator with a Crystal or External CMOS Clock When using Crystal Mode, a 32.768 kHz crystal should be connected between XTAL3 and XTAL4. No other external components are required. The following steps show how to start the SmaRTClock crystal oscillator in software: 1. Set SmaRTClock to Crystal Mode (XMODE = 1). 2. Disable Automatic Gain Control (AGCEN) and enable Bias Doubling (BIASX2) for fast crystal startup. 3. Set the desired loading capacitance (RTC0XCF). 4. Enable power to the SmaRTClock oscillator circuit (RTC0EN = 1). 5. Wait 20 ms. 6. Poll the SmaRTClock Clock Valid Bit (CLKVLD) until the crystal oscillator stabilizes. 7. Poll the SmaRTClock Load Capacitance Ready Bit (LOADRDY) until the load capacitance reaches its programmed value. 8. Enable Automatic Gain Control (AGCEN) and disable Bias Doubling (BIASX2) for maximum power savings. 9. Enable the SmaRTClock missing clock detector. 10.Wait 2 ms. 11. Clear the PMU0CF wake-up source flags. In Crystal Mode, the SmaRTClock oscillator may be driven by an external CMOS clock. The CMOS clock should be applied to XTAL3. XTAL4 should be left floating. The input low voltage (VIL) and input high voltage (VIH) for XTAL3 when used with an external CMOS clock are 0.1 and 0.8 V, respectively. The SmaRTClock oscillator should be configured to its lowest bias setting with AGC disabled. The CLKVLD bit is indeterminate when using a CMOS clock, however, the OSCFAIL bit may be checked 2 ms after SmaRTClock oscillator is powered on to ensure that there is a valid clock on XTAL3. 19.2.2. Using the SmaRTClock Oscillator in Self-Oscillate Mode When using Self-Oscillate Mode, the XTAL3 and XTAL4 pins should be shorted together. The RTC0PIN register can be used to internally short XTAL3 and XTAL4. The following steps show how to configure SmaRTClock for use in Self-Oscillate Mode: 1. Set SmaRTClock to Self-Oscillate Mode (XMODE = 0). 2. Set the desired oscillation frequency: For oscillation at about 20 kHz, set BIASX2 = 0. For oscillation at about 40 kHz, set BIASX2 = 1. 3. The oscillator starts oscillating instantaneously. 4. Fine tune the oscillation frequency by adjusting the load capacitance (RTC0XCF). 207 Rev. 1.0 Si106x/108x 19.2.3. Using the Low Frequency Oscillator (LFO) The low frequency oscillator provides an ultra low power, on-chip clock source to the SmaRTClock. The typical frequency of oscillation is 16.4 kHz 20%. No external components are required to use the LFO, and the XTAL3 and XTAL4 pins do not need to be shorted together. The LFO is only available on the Si108x devices. The following steps show how to configure SmaRTClock for use with the LFO: 1. Enable and select the Low Frequency Oscillator (LFOEN=1). 2. The LFO starts oscillating instantaneously. When the LFO is enabled, the SmaRTClock oscillator increments bit 1 of the 32-bit timer (instead of bit 0). This effectively multiplies the LFO frequency by 2, making the RTC timebase behave as if a 32.768 kHz crystal is connected at the output. 19.2.4. Programmable Load Capacitance The programmable load capacitance has 16 values to support crystal oscillators with a wide range of recommended load capacitance. If Automatic Load Capacitance Stepping is enabled, the crystal load capacitors start at the smallest setting to allow a fast startup time, then slowly increase the capacitance until the final programmed value is reached. The final programmed loading capacitor value is specified using the LOADCAP bits in the RTC0XCF register. The LOADCAP setting specifies the amount of on-chip load capacitance and does not include any stray PCB capacitance. Once the final programmed loading capacitor value is reached, the LOADRDY flag will be set by hardware to logic 1. When using the SmaRTClock oscillator in Self-Oscillate mode, the programmable load capacitance can be used to fine tune the oscillation frequency. In most cases, increasing the load capacitor value will result in a decrease in oscillation frequency.Table 19.2 shows the crystal load capacitance for various settings of LOADCAP. . Table 19.2. SmaRTClock Load Capacitance Settings LOADCAP Crystal Load Capacitance Equivalent Capacitance seen on XTAL3 and XTAL4 0000 4.0 pF 8.0 pF 0001 4.5 pF 9.0 pF 0010 5.0 pF 10.0 pF 0011 5.5 pF 11.0 pF 0100 6.0 pF 12.0 pF 0101 6.5 pF 13.0 pF 0110 7.0 pF 14.0 pF 0111 7.5 pF 15.0 pF 1000 8.0 pF 16.0 pF 1001 8.5 pF 17.0 pF 1010 9.0 pF 18.0 pF 1011 9.5 pF 19.0 pF 1100 10.5 pF 21.0 pF 1101 11.5 pF 23.0 pF Rev. 1.0 208 Si106x/108x Table 19.2. SmaRTClock Load Capacitance Settings (Continued) LOADCAP Crystal Load Capacitance Equivalent Capacitance seen on XTAL3 and XTAL4 1110 12.5 pF 25.0 pF 1111 13.5 pF 27.0 pF 19.2.5. Automatic Gain Control (Crystal Mode Only) and SmaRTClock Bias Doubling Automatic Gain Control allows the SmaRTClock oscillator to trim the oscillation amplitude of a crystal in order to achieve the lowest possible power consumption. Automatic Gain Control automatically detects when the oscillation amplitude has reached a point where it safe to reduce the drive current, therefore, it may be enabled during crystal startup. It is recommended to enable Automatic Gain Control in most systems which use the SmaRTClock oscillator in Crystal Mode. The following are recommended crystal specifications and operating conditions when Automatic Gain Control is enabled: ESR < 50 k Load Capacitance < 10 pF Supply Voltage < 3.0 V Temperature > -20 C When using Automatic Gain Control, it is recommended to perform an oscillation robustness test to ensure that the chosen crystal will oscillate under the worst case condition to which the system will be exposed. The worst case condition that should result in the least robust oscillation is at the following system conditions: lowest temperature, highest supply voltage, highest ESR, highest load capacitance, and lowest bias current (AGC enabled, Bias Double Disabled). To perform the oscillation robustness test, the SmaRTClock oscillator should be enabled and selected as the system clock source. Next, the SYSCLK signal should be routed to a port pin configured as a push-pull digital output. The positive duty cycle of the output clock can be used as an indicator of oscillation robustness. As shown in Figure 19.2, duty cycles less than 55% indicate a robust oscillation. As the duty cycle approaches 60%, oscillation becomes less reliable and the risk of clock failure increases. Increasing the bias current (by disabling AGC) will always improve oscillation robustness and will reduce the output clock's duty cycle. This test should be performed at the worst case system conditions, as results at very low temperatures or high supply voltage will vary from results taken at room temperature or low supply voltage. Safe Operating Zone 25% Low Risk of Clock Failure 55% High Risk of Clock Failure 60% Duty Cycle Figure 19.2. Interpreting Oscillation Robustness (Duty Cycle) Test Results As an alternative to performing the oscillation robustness test, Automatic Gain Control may be disabled at the cost of increased power consumption (approximately 200 nA). Disabling Automatic Gain Control will provide the crystal oscillator with higher immunity against external factors which may lead to clock failure. Automatic Gain Control must be disabled if using the SmaRTClock oscillator in self-oscillate mode. 209 Rev. 1.0 Si106x/108x Table 19.3 shows a summary of the oscillator bias settings. The SmaRTClock Bias Doubling feature allows the self-oscillation frequency to be increased (almost doubled) and allows a higher crystal drive strength in crystal mode. High crystal drive strength is recommended when the crystal is exposed to poor environmental conditions such as excessive moisture. SmaRTClock Bias Doubling is enabled by setting BIASX2 (RTC0XCN.5) to 1. . Table 19.3. SmaRTClock Bias Settings Mode Setting Power Consumption Crystal Bias Double Off, AGC On Lowest 600 nA Bias Double Off, AGC Off Low 800 nA Bias Double On, AGC On High Bias Double On, AGC Off Highest Bias Double Off Low Bias Double On High Self-Oscillate 19.2.6. Missing SmaRTClock Detector The missing SmaRTClock detector is a one-shot circuit enabled by setting MCLKEN (RTC0CN.6) to 1. When the SmaRTClock Missing Clock Detector is enabled, OSCFAIL (RTC0CN.5) is set by hardware if SmaRTClock oscillator remains high or low for more than 100 s. A SmaRTClock Missing Clock detector timeout can trigger an interrupt, wake the device from a low power mode, or reset the device. See Section "11. Interrupt Handler" on page 137, Section "13. Power Management" on page 160, and Section "17. Reset Sources" on page 185 for more information. Note: The SmaRTClock Missing Clock Detector should be disabled when making changes to the oscillator settings in RTC0XCN. 19.2.7. SmaRTClock Oscillator Crystal Valid Detector The SmaRTClock oscillator crystal valid detector is an oscillation amplitude detector circuit used during crystal startup to determine when oscillation has started and is nearly stable. The output of this detector can be read from the CLKVLD bit (RTX0XCN.4). Notes: The CLKVLD bit has a blanking interval of 2 ms. During the first 2 ms after turning on the crystal oscillator, the output of CLKVLD is not valid. This SmaRTClock crystal valid detector (CLKVLD) is not intended for detecting an oscillator failure. The missing SmaRTClock detector (CLKFAIL) should be used for this purpose. Rev. 1.0 210 Si106x/108x 19.3. SmaRTClock Timer and Alarm Function The SmaRTClock timer is a 32-bit counter that, when running (RTC0TR = 1), is incremented every SmaRTClock oscillator cycle. The timer has an alarm function that can be set to generate an interrupt, wake the device from a low power mode, or reset the device at a specific time. See Section "11. Interrupt Handler" on page 137, Section "13. Power Management" on page 160, and Section "17. Reset Sources" on page 185 for more information. The SmaRTClock timer includes an Auto Reset feature, which automatically resets the timer to zero one SmaRTClock cycle after the alarm signal is deasserted. When using Auto Reset, the Alarm match value should always be set to 2 counts less than the desired match value. Auto Reset can be enabled by writing a 1 to ALRM (RTC0CN.2). 19.3.1. Setting and Reading the SmaRTClock Timer Value The 32-bit SmaRTClock timer can be set or read using the six CAPTUREn internal registers. Note that the timer does not need to be stopped before reading or setting its value. The following steps can be used to set the timer value: 1. Write the desired 32-bit set value to the CAPTUREn registers. 2. Write 1 to RTC0SET. This will transfer the contents of the CAPTUREn registers to the SmaRTClock timer. 3. Operation is complete when RTC0SET is cleared to 0 by hardware. The following steps can be used to read the current timer value: 1. Write 1 to RTC0CAP. This will transfer the contents of the timer to the CAPTUREn registers. 2. Poll RTC0CAP until it is cleared to 0 by hardware. 3. A snapshot of the timer value can be read from the CAPTUREn registers 19.3.2. Setting a SmaRTClock Alarm The SmaRTClock alarm function compares the 32-bit value of SmaRTClock Timer to the value of the ALARMn registers. An alarm event is triggered if the SmaRTClock timer is equal to the ALARMn registers. If Auto Reset is enabled, the 32-bit timer will be cleared to zero one SmaRTClock cycle after the alarm event. The SmaRTClock alarm event can be configured to reset the MCU, wake it up from a low power mode, or generate an interrupt. See Section "11. Interrupt Handler" on page 137, Section "13. Power Management" on page 160, and Section "17. Reset Sources" on page 185 for more information. The following steps can be used to set up a SmaRTClock Alarm: 1. Disable SmaRTClock Alarm Events (RTC0AEN = 0). 2. Set the ALARMn registers to the desired value. 3. Enable SmaRTClock Alarm Events (RTC0AEN = 1). Notes: The ALRM bit, which is used as the SmaRTClock Alarm Event flag, is cleared by disabling SmaRTClock Alarm Events (RTC0AEN = 0). If AutoReset is disabled, disabling (RTC0AEN = 0) then Re-enabling Alarm Events (RTC0AEN = 1) after a SmaRTClock Alarm without modifying ALARMn registers will automatically schedule the next alarm after 2^32 SmaRTClock cycles (approximately 36 hours using a 32.768 kHz crystal). The SmaRTClock Alarm Event flag will remain asserted for a maximum of one SmaRTClock cycle. See Section "13. Power Management" on page 160 for information on how to capture a SmaRTClock Alarm event using a flag which is not automatically cleared by hardware. 211 Rev. 1.0 Si106x/108x 19.3.3. Software Considerations for using the SmaRTClock Timer and Alarm The SmaRTClock timer and alarm have two operating modes to suit varying applications. The two modes are described below: Mode 1: The first mode uses the SmaRTClock timer as a perpetual timebase which is never reset to zero. Every 36 hours, the timer is allowed to overflow without being stopped or disrupted. The alarm interval is software managed and is added to the ALRMn registers by software after each alarm. This allows the alarm match value to always stay ahead of the timer by one software managed interval. If software uses 32-bit unsigned addition to increment the alarm match value, then it does not need to handle overflows since both the timer and the alarm match value will overflow in the same manner. This mode is ideal for applications which have a long alarm interval (e.g. 24 or 36 hours) and/or have a need for a perpetual timebase. An example of an application that needs a perpetual timebase is one whose wake-up interval is constantly changing. For these applications, software can keep track of the number of timer overflows in a 16-bit variable, extending the 32-bit (36 hour) timer to a 48-bit (272 year) perpetual timebase. Mode 2: The second mode uses the SmaRTClock timer as a general purpose up counter which is auto reset to zero by hardware after each alarm. The alarm interval is managed by hardware and stored in the ALRMn registers. Software only needs to set the alarm interval once during device initialization. After each alarm, software should keep a count of the number of alarms that have occurred in order to keep track of time. This mode is ideal for applications that require minimal software intervention and/or have a fixed alarm interval. This mode is the most power efficient since it requires less CPU time per alarm. Rev. 1.0 212 Si106x/108x Internal Register Definition 19.4. RTC0CN: SmaRTClock Control Bit 7 6 5 4 3 2 Name RTC0EN MCLKEN OSCFAIL RTC0TR RTC0AEN ALRM Type R/W R/W R/W R/W R/W R/W R/W R/W Reset 0 0 Varies 0 0 0 0 0 SmaRTClock Address = 0x04 Bit Name 7 RTC0EN SmaRTClock Enable. 1 RTC0SET RTC0CAP Function 6 Enables/disables the SmaRTClock oscillator and associated bias currents. 0: SmaRTClock oscillator disabled. 1: SmaRTClock oscillator enabled. MCLKEN Missing SmaRTClock Detector Enable. 5 Enables/disables the missing SmaRTClock detector. 0: Missing SmaRTClock detector disabled. 1: Missing SmaRTClock detector enabled. OSCFAIL SmaRTClock Oscillator Fail Event Flag. 4 3 RTC0TR 0 Set by hardware when a missing SmaRTClock detector timeout occurs. Must be cleared by software. The value of this bit is not defined when the SmaRTClock oscillator is disabled. SmaRTClock Timer Run Control. Controls if the SmaRTClock timer is running or stopped (holds current value). 0: SmaRTClock timer is stopped. 1: SmaRTClock timer is running. RTC0AEN SmaRTClock Alarm Enable. 1 Enables/disables the SmaRTClock alarm function. Also clears the ALRM flag. 0: SmaRTClock alarm disabled. 1: SmaRTClock alarm enabled. ALRM SmaRTClock Alarm Event Read: Write: Flag and Auto Reset 0: Disable Auto Reset. 0: SmaRTClock alarm Enable event flag is de-asserted. 1: Enable Auto Reset. Reads return the state of the 1: SmaRTClock alarm event flag is asserted. alarm event flag. Writes enable/disable the Auto Reset function. RTC0SET SmaRTClock Timer Set. 0 Writing 1 initiates a SmaRTClock timer set operation. This bit is cleared to 0 by hardware to indicate that the timer set operation is complete. RTC0CAP SmaRTClock Timer Capture. 2 Writing 1 initiates a SmaRTClock timer capture operation. This bit is cleared to 0 by hardware to indicate that the timer capture operation is complete. Note: The ALRM flag will remain asserted for a maximum of one SmaRTClock cycle. See Section "Power Management" on page 160 for information on how to capture a SmaRTClock Alarm event using a flag which is not automatically cleared by hardware. 213 Rev. 1.0 Si106x/108x Internal Register Definition 19.5. RTC0XCN: SmaRTClock Oscillator Control Bit 7 6 5 4 3 2 1 0 Name AGCEN XMODE BIASX2 CLKVLD Type R/W R/W R/W R R R R R Reset 0 0 0 0 0 0 0 0 SmaRTClock Address = 0x05 Bit Name 7 AGCEN Function SmaRTClock Oscillator Automatic Gain Control (AGC) Enable. 0: AGC disabled. 1: AGC enabled. 6 XMODE SmaRTClock Oscillator Mode. Selects Crystal or Self Oscillate Mode. 0: Self-Oscillate Mode selected. 1: Crystal Mode selected. 5 BIASX2 SmaRTClock Oscillator Bias Double Enable. Enables/disables the Bias Double feature. 0: Bias Double disabled. 1: Bias Double enabled. 4 CLKVLD SmaRTClock Oscillator Crystal Valid Indicator. Indicates if oscillation amplitude is sufficient for maintaining oscillation. 0: Oscillation has not started or oscillation amplitude is too low to maintain oscillation. 1: Sufficient oscillation amplitude detected. 3:0 Unused Read = 0000b; Write = Don't Care. Rev. 1.0 214 Si106x/108x Internal Register Definition 19.6. RTC0XCF: SmaRTClock Oscillator Configuration Bit 7 6 Name AUTOSTP 5 4 3 LOADRDY R/W R R R Reset 0 0 0 0 0 R/W Varies SmaRTClock Address = 0x06 Bit Name AUTOSTP 1 LOADCAP Type 7 2 Varies Varies Varies Function Automatic Load Capacitance Stepping Enable. Enables/disables automatic load capacitance stepping. 0: Load capacitance stepping disabled. 1: Load capacitance stepping enabled. 6 LOADRDY Load Capacitance Ready Indicator. Set by hardware when the load capacitance matches the programmed value. 0: Load capacitance is currently stepping. 1: Load capacitance has reached it programmed value. 5:4 Unused Read = 00b; Write = Don't Care. 3:0 LOADCAP Load Capacitance Programmed Value. Holds the user's desired value of the load capacitance. See Table 19.2 on page 208. Internal Register Definition 19.7. RTC0PIN: SmaRTClock Pin Configuration Bit 7 6 5 4 Name RTC0PIN Type W Reset 0 1 1 0 SmaRTClock Address = 0x07 Bit Name 7:0 3 2 1 0 0 1 1 1 Function RTC0PIN SmaRTClock Pin Configuration. Writing 0xE7 to this register forces XTAL3 and XTAL4 to be internally shorted for use with Self Oscillate Mode. Writing 0x67 returns XTAL3 and XTAL4 to their normal configuration. 215 Rev. 1.0 Si106x/108x Internal Register Definition 19.8. CAPTUREn: SmaRTClock Timer Capture Bit 7 6 5 4 3 2 1 0 CAPTURE[31:0] Name Type R/W R/W R/W R/W R/W R/W R/W R/W Reset 0 0 0 0 0 0 0 0 SmaRTClock Addresses: CAPTURE0 = 0x00; CAPTURE1 = 0x01; CAPTURE2 =0x02; CAPTURE3: 0x03. Bit Name Function 7:0 CAPTURE[31:0] SmaRTClock Timer Capture. These 4 registers (CAPTURE3-CAPTURE0) are used to read or set the 32-bit SmaRTClock timer. Data is transferred to or from the SmaRTClock timer when the RTC0SET or RTC0CAP bits are set. Note: The least significant bit of the timer capture value is in CAPTURE0.0. Internal Register Definition 19.9. ALARMn: SmaRTClock Alarm Programmed Value Bit 7 6 5 4 3 2 1 0 ALARM[31:0] Name Type R/W R/W R/W R/W R/W R/W R/W R/W Reset 0 0 0 0 0 0 0 0 SmaRTClock Addresses: ALARM0 = 0x08; ALARM1 = 0x09; ALARM2 = 0x0A; ALARM3 = 0x0B Bit Name Function 7:0 ALARM[31:0] SmaRTClock Alarm Programmed Value. These 4 registers (ALARM3-ALARM0) are used to set an alarm event for the SmaRTClock timer. The SmaRTClock alarm should be disabled (RTC0AEN=0) when updating these registers. Note: The least significant bit of the alarm programmed value is in ALARM0.0. Rev. 1.0 216 Si106x/108x 20. Si106x/108xPort Input/Output Digital and analog resources are available through 11 I/O pins. The radio peripheral provides an additional 4 GPIO pins which are independent of the pins described in this chapter. Port pins are organized as three byte-wide ports. Port pins P0.0-P0.6, P1.4-P1.6, and P2.7 can be defined as digital or analog I/O. Digital I/O pins can be assigned to one of the internal digital resources or used as general purpose I/O (GPIO). Analog I/O pins are used by the internal analog resources. P0.7, P1.0-P1.3 are dedicated for communication with the radio peripheral. P2.7 can be used as GPIO and is shared with the C2 Interface Data signal (C2D). See Section "33. Device Specific Behavior" on page 352 for more details. The designer has complete control over which digital and analog functions are assigned to individual Port pins, limited only by the number of physical I/O pins. This resource assignment flexibility is achieved through the use of a Priority Crossbar Decoder. See Section 20.3 for more information on the Crossbar. All Px.x Port I/Os are 5V tolerant when used as digital inputs or open-drain outputs. For Port I/Os configured as push-pull outputs, current is sourced from the VDD_MCU supply. Port I/Os used for analog functions can operate up to the VDD_MCU supply voltage. See Section 20.1 for more information on Port I/O operating modes and the electrical specifications chapter for detailed electrical specifications. XBR0, XBR1, XBR2, PnSKIP Registers Port Match P0MASK, P0MAT P1MASK, P1MAT External Interrupts EX0 and EX1 Priority Decoder Highest Priority UART 4 (Internal Digital Signals) SPI0 SPI1 SMBus CP0 CP1 Outputs P0.0 2 Digital Crossbar 8 4 8 7 T0, T1 P0 I/O Cells P0.6 SYSCLK PCA Lowest Priority PnMDOUT, PnMDIN Registers 2 P1.4 P1 I/O Cells P1.5 P1.6 2 8 (Port Latches) P0 8 (P0.0-P0.7) 8 P1 (P1.0-P1.7) 8 P2 (P2.0-P2.7) P2 I/O Cell P2.7 To Analog Peripherals (ADC0, CP0, and CP1 inputs, VREF, AGND) No analog functionality available on P2.7 Note: P0.7, P1.0, P1.1, P1.2 and P1.3 are internally connected to the radio peripheral. P1.7 and P2.0 - P2.6 are not internally or externally connected. Figure 20.1. Port I/O Functional Block Diagram Rev. 1.0 217 Si106x/108x 20.1. Port I/O Modes of Operation Port pins P0.0-P0.6 and P1.4-P1.6 use the Port I/O cell shown in Figure 20.2. Each Port I/O cell can be configured by software for analog I/O or digital I/O using the PnMDIN registers. On reset, all Port I/O cells default to a digital high impedance state with weak pull-ups enabled. 20.1.1. Port Pins Configured for Analog I/O Any pins to be used as Comparator or ADC input, external oscillator input/output, or AGND, VREF, or Current Reference output should be configured for analog I/O (PnMDIN.n = 0). When a pin is configured for analog I/O, its weak pullup and digital receiver are disabled. In most cases, software should also disable the digital output drivers. Port pins configured for analog I/O will always read back a value of 0 regardless of the actual voltage on the pin. Configuring pins as analog I/O saves power and isolates the Port pin from digital interference. Port pins configured as digital inputs may still be used by analog peripherals; however, this practice is not recommended and may result in measurement errors. 20.1.2. Port Pins Configured For Digital I/O Any pins to be used by digital peripherals (UART, SPI, SMBus, etc.), external digital event capture functions, or as GPIO should be configured as digital I/O (PnMDIN.n = 1). For digital I/O pins, one of two output modes (push-pull or open-drain) must be selected using the PnMDOUT registers. Push-pull outputs (PnMDOUT.n = 1) drive the Port pad to the VDD_MCU or GND supply rails based on the output logic value of the Port pin. Open-drain outputs have the high side driver disabled; therefore, they only drive the Port pad to GND when the output logic value is 0 and become high impedance inputs (both high and low drivers turned off) when the output logic value is 1. When a digital I/O cell is placed in the high impedance state, a weak pull-up transistor pulls the Port pad to the VDD_MCU supply voltage to ensure the digital input is at a defined logic state. Weak pull-ups are disabled when the I/O cell is driven to GND to minimize power consumption and may be globally disabled by setting WEAKPUD to 1. The user must ensure that digital I/O are always internally or externally pulled or driven to a valid logic state. Port pins configured for digital I/O always read back the logic state of the Port pad, regardless of the output logic value of the Port pin. WEAKPUD (Weak Pull-Up Disable) PnMDOUT.x (1 for push-pull) (0 for open-drain) VDD/DC+ VDD/DC+ XBARE (Crossbar Enable) (WEAK) PORT PAD Pn.x - Output Logic Value (Port Latch or Crossbar) PnMDIN.x (1 for digital) (0 for analog) To/From Analog Peripheral GND Pn.x - Input Logic Value (Reads 0 when pin is configured as an analog I/O) Figure 20.2. Port I/O Cell Block Diagram 218 Rev. 1.0 Si106x/108x 20.1.3. Interfacing Port I/O to 5 V and 3.3 V Logic All Port I/O configured for digital, open-drain operation are capable of interfacing to digital logic operating at a supply voltage higher than 4.5 V and less than 5.25 V. When the supply voltage is in the range of 1.8 to 2.2 V, the I/O may also interface to digital logic operating between 3.0 to 3.6 V if the input signal frequency is less than 12.5 MHz or less than 25 MHz if the signal rise time (10% to 90%) is less than 1.2 ns. When operating at a supply voltage above 2.2 V, the device should not interface to 3.3 V logic; however, interfacing to 5 V logic is permitted. An external pull-up resistor to the higher supply voltage is typically required for most systems. Important Notes: When interfacing to a signal that is between 4.5 and 5.25 V, the maximum clock frequency that may be input on a GPIO pin is 12.5 MHz. The exception to this rule is when routing an external CMOS clock to P0.3, in which case, a signal up to 25 MHz is valid as long as the rise time (10% to 90%) is shorter than 1.8 ns. When the supply voltage is less than 2.2 V and interfacing to a signal that is between 3.0 and 3.6 V, the maximum clock frequency that may be input on a GPIO pin is 3.125 MHz. The exception to this rule is when routing an external CMOS clock to P0.3, in which case, a signal up to 25 MHz is valued as long as the rise time (10% to 90%) is shorter than 1.2 ns. In a multi-voltage interface, the external pull-up resistor should be sized to allow a current of at least 150 A to flow into the Port pin when the supply voltage is between (VDD_MCU/DC+ plus 0.4 V) and (VDD_MCU/DC+ plus 1.0 V). Once the Port pad voltage increases beyond this range, the current flowing into the Port pin is minimal. These guidelines only apply to multi-voltage interfaces. Port I/Os may always interface to digital logic operating at the same supply voltage. 20.1.4. Increasing Port I/O Drive Strength Port I/O output drivers support a high and low drive strength; the default is low drive strength. The drive strength of a Port I/O can be configured using the PnDRV registers. See Section "4. Electrical Characteristics" on page 42 for the difference in output drive strength between the two modes. 20.2. Assigning Port I/O Pins to Analog and Digital Functions Port I/O pins P0.0-P0.6 and P1.4-P1.6 can be assigned to various analog, digital, and external interrupt functions. The Port pins assuaged to analog functions should be configured for analog I/O and Port pins assuaged to digital or external interrupt functions should be configured for digital I/O. 20.2.1. Assigning Port I/O Pins to Analog Functions Table 20.1 shows all available analog functions that need Port I/O assignments. Port pins selected for these analog functions should have their digital drivers disabled (PnMDOUT.n = 0 and Port Latch = 1) and their corresponding bit in PnSKIP set to 1. This reserves the pin for use by the analog function and does not allow it to be claimed by the Crossbar. Table 20.1 shows the potential mapping of Port I/O to each analog function. Rev. 1.0 219 Si106x/108x Table 20.1. Port I/O Assignment for Analog Functions Analog Function Potentially Assignable Port Pins SFR(s) used for Assignment ADC Input P0.0-P0.6 and P1.4-P1.6 ADC0MX, PnSKIP Comparator0 Input P0.0-P0.6 and P1.4-P1.6 CPT0MX, PnSKIP Comparator1 Input P0.0-P0.6 and P1.4-P1.6 CPT1MX, PnSKIP Voltage Reference (VREF0) P0.0 REF0CN, PnSKIP Analog Ground Reference (AGND) P0.1 REF0CN, PnSKIP External Oscillator Input (XTAL1) P0.2 OSCXCN, PnSKIP External Oscillator Output (XTAL2) P0.3 OSCXCN, PnSKIP 20.2.2. Assigning Port I/O Pins to Digital Functions Any Port pins not assigned to analog functions may be assigned to digital functions or used as GPIO. Most digital functions rely on the Crossbar for pin assignment; however, some digital functions bypass the Crossbar in a manner similar to the analog functions listed above. Port pins used by these digital functions and any Port pins selected for use as GPIO should have their corresponding bit in PnSKIP set to 1. Table 20.2 shows all available digital functions and the potential mapping of Port I/O to each digital function. Table 20.2. Port I/O Assignment for Digital Functions Digital Function UART0, SPI1, SPI0, SMBus, CP0 and CP1 Outputs, System Clock Output, PCA0, Timer0 and Timer1 External Inputs. Any pin used for GPIO Potentially Assignable Port Pins SFR(s) used for Assignment Any Port pin available for assignment by the Crossbar. This includes P0.0-P2.6 pins which have their PnSKIP bit set to 0. Note: The Crossbar will always assign UART0 and SPI1 pins to fixed locations. XBR0, XBR1, XBR2 P0.0-P0.6 and P1.4-P1.6 P0SKIP, P1SKIP, P2SKIP 20.2.3. Assigning Port I/O Pins to External Digital Event Capture Functions External digital event capture functions can be used to trigger an interrupt or wake the device from a low power mode when a transition occurs on a digital I/O pin. The digital event capture functions do not require dedicated pins and will function on both GPIO pins (PnSKIP = 1) and pins in use by the Crossbar (PnSKIP = 0). External digital even capture functions cannot be used on pins configured for analog I/O. Table 20.3 shows all available external digital event capture functions. 220 Rev. 1.0 Si106x/108x Table 20.3. Port I/O Assignment for External Digital Event Capture Functions Digital Function Potentially Assignable Port Pins SFR(s) used for Assignment External Interrupt 0 P0.0-P0.6 IT01CF External Interrupt 1 P0.0-P0.6 IT01CF P0.0-P0.6 and P1.4-P1.6 P0MASK, P0MAT P1MASK, P1MAT Port Match 20.3. Priority Crossbar Decoder The Priority Crossbar Decoder assigns a Port I/O pin to each software selected digital function using the fixed peripheral priority order shown in Figure 20.3. The registers XBR0, XBR1, and XBR2 defined in SFR Definition 20.1, SFR Definition 20.2, and SFR Definition 20.3 are used to select digital functions in the Crossbar. The Port pins available for assignment by the Crossbar include all Port pins (P0.0-P2.6) which have their corresponding bit in PnSKIP set to 0. From Figure 20.3, the highest priority peripheral is UART0. If UART0 is selected in the Crossbar (using the XBRn registers), then P0.4 and P0.5 will be assigned to UART0. The next highest priority peripheral is SPI1. SPI1 is dedicated to the radio and must always be enabled. The user should ensure that the pins to be assigned by the Crossbar have their PnSKIP bits set to 0. For all remaining digital functions selected in the Crossbar, starting at the top of Figure 20.3 going down, the least-significant unskipped, unassigned Port pin(s) are assigned to that function. If a Port pin is already assigned (e.g., UART0 or SPI1 pins), or if its PnSKIP bit is set to 1, then the Crossbar will skip over the pin and find next available unskipped, unassigned Port pin. All Port pins used for analog functions, GPIO, or dedicated digital functions such as the EMIF should have their PnSKIP bit set to 1. Figure 20.3 shows the Crossbar Decoder priority with no Port pins skipped (P0SKIP, P1SKIP, P2SKIP = 0x00); Figure 20.4 shows the Crossbar Decoder priority with the External Oscillator pins (XTAL1 and XTAL2) skipped (P0SKIP = 0x0C). Notes: The Crossbar must be enabled (XBARE = 1) before any Port pin is used as a digital output. Port output drivers are disabled while the Crossbar is disabled. When SMBus is selected in the Crossbar, the pins associated with SDA and SCL will automatically be forced into open-drain output mode regardless of the PnMDOUT setting. SPI0 can be operated in either 3-wire or 4-wire modes, depending on the state of the NSSMD1NSSMD0 bits in register SPI0CN. The NSS signal is only routed to a Port pin when 4-wire mode is selected. When SPI0 is selected in the Crossbar, the SPI0 mode (3-wire or 4-wire) will affect the pinout of all digital functions lower in priority than SPI0. For given XBRn, PnSKIP, and SPInCN register settings, one can determine the I/O pin-out of the device using Figure 20.3 and Figure 20.4. Rev. 1.0 221 Si106x/108x P1 3 4 5 6 0 0 0 0 0 0 0 7 0 1 2 0 0 0 Radio Shutdown Input RX0 SCK (SPI1) MISO (SPI1) MOSI (SPI1) SCK (SPI0) MISO (SPI0) MOSI (SPI0) 3 4 5 6 1 0 0 Radio Serial Interface Select Input TX0 C2D 2 NSS* (SPI0) SDA 7 0 1 2 3 4 5 6 7 0 0 0 0 0 0 0 0 X No Connect No Connect No Connect XTAL2 1 No Connect No Connect No Connect XTAL1 0 Radio Serial Interface No Connect AGND PIN I/O P2 No Connect SF Signals VREF CNVSTR P0 SCL CP0 CP0A CP1 CP1A /SYSCLK CEX0 CEX1 CEX2 CEX3 CEX4 CEX5 ECI T0 T1 P0SKIP[0:7] 0 1 P1SKIP[0:7] P2SKIP[0:7] Figure 20.3. Crossbar Priority Decoder with No Pins Skipped 222 Rev. 1.0 Si106x/108x P1 3 4 5 6 0 0 0 0 0 0 0 7 0 1 2 1 1 0 Radio Shutdown Input RX0 SCK (SPI1) MISO (SPI1) MOSI (SPI1) NSS* (SPI1) SCK (SPI0) MISO (SPI0) 4 5 6 1 1 1 Radio Serial Interface Select Input TX0 3 C2D 2 MOSI (SPI0) NSS* (SPI0) 7 0 1 2 3 4 5 6 7 1 0 0 0 0 0 0 0 X No Connect No Connect No Connect XTAL2 1 No Connect No Connect No Connect XTAL1 0 Radio Serial Interface No Connect AGND PIN I/O P2 No Connect SF Signals VREF CNVSTR P0 SDA SCL CP0 CP0A CP1 CP1A /SYSCLK CEX0 CEX1 CEX2 CEX3 CEX4 CEX5 ECI T0 T1 P0SKIP[0:7] 1 1 P1SKIP[0:7] P2SKIP[0:7] Figure 20.4. Crossbar Priority Decoder with Crystal Pins Skipped Rev. 1.0 223 Si106x/108x SFR Definition 20.1. XBR0: Port I/O Crossbar Register 0 Bit 7 6 5 4 3 2 1 0 Name CP1AE CP1E CP0AE CP0E SYSCKE SMB0E SPI0E URT0E Type R/W R/W R/W R/W R/W R/W R/W R/W Reset 0 0 0 0 0 0 0 0 SFR Page = 0x0; SFR Address = 0xE1 Bit Name 7 CP1AE Function Comparator1 Asynchronous Output Enable. 0: Asynchronous CP1 output unavailable at Port pin. 1: Asynchronous CP1 output routed to Port pin. 6 CP1E Comparator1 Output Enable. 0: CP1 output unavailable at Port pin. 1: CP1 output routed to Port pin. 5 CP0AE Comparator0 Asynchronous Output Enable. 0: Asynchronous CP0 output unavailable at Port pin. 1: Asynchronous CP0 output routed to Port pin. 4 CP0E Comparator0 Output Enable. 0: CP1 output unavailable at Port pin. 1: CP1 output routed to Port pin. 3 SYSCKE SYSCLK Output Enable. 0: SYSCLK output unavailable at Port pin. 1: SYSCLK output routed to Port pin. 2 SMB0E SMBus I/O Enable. 0: SMBus I/O unavailable at Port pin. 1: SDA and SCL routed to Port pins. 1 SPI0E SPI0 I/O Enable 0: SPI0 I/O unavailable at Port pin. 1: SCK, MISO, and MOSI (for SPI0) routed to Port pins. NSS (for SPI0) routed to Port pin only if SPI0 is configured to 4-wire mode. 0 URT0E UART0 Output Enable. 0: UART I/O unavailable at Port pin. 1: TX0 and RX0 routed to Port pins P0.4 and P0.5. Note: SPI0 can be assigned either 3 or 4 Port I/O pins. 224 Rev. 1.0 Si106x/108x SFR Definition 20.2. XBR1: Port I/O Crossbar Register 1 Bit 7 Name 6 5 4 3 SPI1E T1E T0E ECIE 2 1 0 PCA0ME[2:0] Type R/W R/W R/W R/W R/W R/W R/W R/W Reset 0 0 0 0 0 0 0 0 SFR Page = 0x0; SFR Address = 0xE2 Bit Name 7 Unused 6 SPI1E Function Read = 0b; Write = Don't Care. Radio Serial Interface (SPI1) Enable. 0: Radio peripheral unavailable. 1: SCK (for radio) routed to P1.0. SDO (for radio) routed to P1.1. SDI (for radio) routed to P1.2 nSEL (for radio) is routed to P1.3. SDN1 (for radio) routed to P0.7 5 T1E Timer1 Input Enable. 0: T1 input unavailable at Port pin. 1: T1 input routed to Port pin. 4 T0E Timer0 Input Enable. 0: T0 input unavailable at Port pin. 1: T0 input routed to Port pin. 3 ECIE PCA0 External Counter Input (ECI) Enable. 0: PCA0 external counter input unavailable at Port pin. 1: PCA0 external counter input routed to Port pin. 2:0 PCA0ME PCA0 Module I/O Enable. 000: All PCA0 I/O unavailable at Port pin. 001: CEX0 routed to Port pin. 010: CEX0, CEX1 routed to Port pins. 011: CEX0, CEX1, CEX2 routed to Port pins. 100: CEX0, CEX1, CEX2 CEX3 routed to Port pins. 101: CEX0, CEX1, CEX2, CEX3, CEX4 routed to Port pins. 110: CEX0, CEX1, CEX2, CEX3, CEX4, CEX5 routed to Port pins. 111: Reserved. Note: SPI1 can be assigned either 3 or 4 Port I/O pins. Rev. 1.0 225 Si106x/108x SFR Definition 20.3. XBR2: Port I/O Crossbar Register 2 Bit 7 6 5 4 3 2 1 0 Name WEAKPUD XBARE Type R/W R/W R/W R/W R/W R/W R/W R/W Reset 0 0 0 0 0 0 0 0 SFR Page = 0x0; SFR Address = 0xE3 Bit 7 Name Function WEAKPUD Port I/O Weak Pullup Disable 0: Weak Pullups enabled (except for Port I/O pins configured for analog mode). 6 XBARE Crossbar Enable 0: Crossbar disabled. 1: Crossbar enabled. 5:0 Unused Read = 000000b; Write = Don't Care. Note: The Crossbar must be enabled (XBARE = 1) to use any Port pin as a digital output. 20.4. Port Match Port match functionality allows system events to be triggered by a logic value change on P0 or P1. A software controlled value stored in the PnMAT registers specifies the expected or normal logic values of P0 and P1. A Port mismatch event occurs if the logic levels of the Port's input pins no longer match the software controlled value. This allows Software to be notified if a certain change or pattern occurs on P0 or P1 input pins regardless of the XBRn settings. The PnMASK registers can be used to individually select which P0 and P1 pins should be compared against the PnMAT registers. A Port mismatch event is generated if (P0 & P0MASK) does not equal (PnMAT & P0MASK) or if (P1 & P1MASK) does not equal (PnMAT & P1MASK). A Port mismatch event may be used to generate an interrupt or wake the device from a low power mode. See Section "11. Interrupt Handler" on page 137 and Section "13. Power Management" on page 160 for more details on interrupt and wake-up sources. 226 Rev. 1.0 Si106x/108x SFR Definition 20.4. P0MASK: Port0 Mask Register Bit 7 6 5 4 3 Name P0MASK[7:0] Type R/W Reset 0 0 0 0 0 2 1 0 0 0 0 SFR Page= 0x0; SFR Address = 0xC7 Bit 7:0 Name Function P0MASK[7:0] Port0 Mask Value. Selects the P0 pins to be compared with the corresponding bits in P0MAT. 0: P0.n pin pad logic value is ignored and cannot cause a Port Mismatch event. 1: P0.n pin pad logic value is compared to P0MAT.n. SFR Definition 20.5. P0MAT: Port0 Match Register Bit 7 6 5 4 3 Name P0MAT[7:0] Type R/W Reset 1 1 1 1 1 2 1 0 1 1 1 SFR Page= 0x0; SFR Address = 0xD7 Bit 7 :0 Name Function P0MAT[7:0] Port 0 Match Value. Match comparison value used on Port 0 for bits in P0MASK which are set to 1. 0: P0.n pin logic value is compared with logic LOW. 1: P0.n pin logic value is compared with logic HIGH. Rev. 1.0 227 Si106x/108x SFR Definition 20.6. P1MASK: Port1 Mask Register Bit 7 6 5 4 3 Name P1MASK[7:0] Type R/W Reset 0 0 0 0 0 SFR Page= 0x0; SFR Address = 0xBF Bit Name 7:0 2 1 0 0 0 0 Function P1MASK[7:0] Port 1 Mask Value. Selects P1 pins to be compared to the corresponding bits in P1MAT. 0: P1.n pin logic value is ignored and cannot cause a Port Mismatch event. 1: P1.n pin logic value is compared to P1MAT.n. Note: P0.7, P1.2, P1.5, P1.6 and P1.7 are internally connected to the radio peripheral. P1.0, P1.1, P1.3, P1.4, P2.2, P2.3, P2.5, and P2.6 is not externally or internally connected. SFR Definition 20.7. P1MAT: Port1 Match Register Bit 7 6 5 4 3 Name P1MAT[7:0] Type R/W Reset 1 1 1 1 SFR Page = 0x0; SFR Address = 0xCF Bit Name 7:0 1 2 1 0 1 1 1 Function P1MAT[7:0] Port 1 Match Value. Match comparison value used on Port 1 for bits in P1MASK which are set to 1. 0: P1.n pin logic value is compared with logic LOW. 1: P1.n pin logic value is compared with logic HIGH. Note: P0.7, P1.2, P1.5, P1.6 and P1.7 are internally connected to the radio peripheral. P1.0, P1.1, P1.3, P1.4, P2.2, P2.3, P2.5, and P2.6 is not externally or internally connected. 228 Rev. 1.0 Si106x/108x 20.5. Special Function Registers for Accessing and Configuring Port I/O All Port I/O are accessed through corresponding special function registers (SFRs) that are both byte addressable and bit addressable. When writing to a Port, the value written to the SFR is latched to maintain the output data value at each pin. When reading, the logic levels of the Port's input pins are returned regardless of the XBRn settings (i.e., even when the pin is assigned to another signal by the Crossbar, the Port register can always read its corresponding Port I/O pin). The exception to this is the execution of the read-modify-write instructions that target a Port Latch register as the destination. The read-modify-write instructions when operating on a Port SFR are the following: ANL, ORL, XRL, JBC, CPL, INC, DEC, DJNZ and MOV, CLR or SETB, when the destination is an individual bit in a Port SFR. For these instructions, the value of the latch register (not the pin) is read, modified, and written back to the SFR. Each Port has a corresponding PnSKIP register which allows its individual Port pins to be assigned to digital functions or skipped by the Crossbar. All Port pins used for analog functions, GPIO, or dedicated digital functions such as the EMIF should have their PnSKIP bit set to 1. The Port input mode of the I/O pins is defined using the Port Input Mode registers (PnMDIN). Each Port cell can be configured for analog or digital I/O. This selection is required even for the digital resources selected in the XBRn registers, and is not automatic. The only exception to this is P2.7, which can only be used for digital I/O. The output driver characteristics of the I/O pins are defined using the Port Output Mode registers (PnMDOUT). Each Port Output driver can be configured as either open drain or push-pull. This selection is required even for the digital resources selected in the XBRn registers, and is not automatic. The only exception to this is the SMBus (SDA, SCL) pins, which are configured as open-drain regardless of the PnMDOUT settings. The drive strength of the output drivers are controlled by the Port Drive Strength (PnDRV) registers. The default is low drive strength. See Section "4. Electrical Characteristics" on page 42 for the difference in output drive strength between the two modes. Rev. 1.0 229 Si106x/108x SFR Definition 20.8. P0: Port0 Bit 7 6 5 4 Name P0[7:0] Type R/W Reset 1 1 1 1 3 2 1 0 1 1 1 1 SFR Page = All Pages; SFR Address = 0x80; Bit-Addressable Bit Name Description Write 7:0 P0[7:0] Read 0: Set output latch to logic LOW. Sets the Port latch logic value or reads the Port pin 1: Set output latch to logic logic state in Port cells con- HIGH. figured for digital I/O. Port 0 Data. 0: P0.n Port pin is logic LOW. 1: P0.n Port pin is logic HIGH. SFR Definition 20.9. P0SKIP: Port0 Skip Bit 7 6 5 4 3 Name P0SKIP[7:0] Type R/W Reset 0 0 0 0 SFR Page= 0x0; SFR Address = 0xD4 Bit Name 7:0 0 2 1 0 0 0 0 Function P0SKIP[7:0] Port 0 Crossbar Skip Enable Bits. These bits select Port 0 pins to be skipped by the Crossbar Decoder. Port pins used for analog, special functions or GPIO should be skipped by the Crossbar. 0: Corresponding P0.n pin is not skipped by the Crossbar. 1: Corresponding P0.n pin is skipped by the Crossbar. 230 Rev. 1.0 Si106x/108x SFR Definition 20.10. P0MDIN: Port0 Input Mode Bit 7 6 5 4 3 Name P0MDIN[7:0] Type R/W Reset 1 1 1 1 1 SFR Page= 0x0; SFR Address = 0xF1 Bit Name 7:0 P0MDIN[7:0] 2 1 0 1 1 1 Function Analog Configuration Bits for P0.7-P0.0 (respectively). Port pins configured for analog mode have their weak pullup, and digital receiver disabled. The digital driver is not explicitly disabled. 0: Corresponding P0.n pin is configured for analog mode. 1: Corresponding P0.n pin is not configured for analog mode. SFR Definition 20.11. P0MDOUT: Port0 Output Mode Bit 7 6 5 4 3 Name P0MDOUT[7:0] Type R/W Reset 0 0 0 0 SFR Page = 0x0; SFR Address = 0xA4 Bit Name 7:0 0 2 1 0 0 0 0 Function P0MDOUT[7:0] Output Configuration Bits for P0.7-P0.0 (respectively). These bits control the digital driver even when the corresponding bit in register P0MDIN is logic 0. 0: Corresponding P0.n Output is open-drain. 1: Corresponding P0.n Output is push-pull. Rev. 1.0 231 Si106x/108x SFR Definition 20.12. P0DRV: Port0 Drive Strength Bit 7 6 5 4 3 Name P0DRV[7:0] Type R/W Reset 0 0 0 0 SFR Page = 0xF; SFR Address = 0xA4 Bit Name 7:0 0 2 1 0 0 0 0 Function P0DRV[7:0] Drive Strength Configuration Bits for P0.7-P0.0 (respectively). Configures digital I/O Port cells to high or low output drive strength. 0: Corresponding P0.n Output has low output drive strength. 1: Corresponding P0.n Output has high output drive strength. 232 Rev. 1.0 Si106x/108x SFR Definition 20.13. P1: Port1 Bit 7 6 5 4 Name P1[7:0] Type R/W Reset 1 1 1 1 3 2 1 0 1 1 1 1 SFR Page = All Pages; SFR Address = 0x90; Bit-Addressable Bit Name Description Write 7:0 P1[7:0] Read 0: Set output latch to logic LOW. Sets the Port latch logic value or reads the Port pin 1: Set output latch to logic logic state in Port cells con- HIGH. figured for digital I/O. Port 1 Data. 0: P1.n Port pin is logic LOW. 1: P1.n Port pin is logic HIGH. Note: P0.7, P1.2, P1.5, P1.6 and P1.7 are internally connected to the radio peripheral. P1.0, P1.1, P1.3, P1.4, P2.2, P2.3, P2.5, and P2.6 is not externally or internally connected. SFR Definition 20.14. P1SKIP: Port1 Skip Bit 7 6 5 4 3 Name P1SKIP[7:0] Type R/W Reset 0 0 0 0 SFR Page = 0x0; SFR Address = 0xD5 Bit Name 7:0 0 2 1 0 0 0 0 Function P1SKIP[7:0] Port 1 Crossbar Skip Enable Bits. These bits select Port 1 pins to be skipped by the Crossbar Decoder. Port pins used for analog, special functions or GPIO should be skipped by the Crossbar. 0: Corresponding P1.n pin is not skipped by the Crossbar. 1: Corresponding P1.n pin is skipped by the Crossbar. Note: P0.7, P1.2, P1.5, P1.6 and P1.7 are internally connected to the radio peripheral. P1.0, P1.1, P1.3, P1.4, P2.2, P2.3, P2.5, and P2.6 is not externally or internally connected. Rev. 1.0 233 Si106x/108x SFR Definition 20.15. P1MDIN: Port1 Input Mode Bit 7 6 5 4 3 Name P1MDIN[7:0] Type R/W Reset 1 1 1 1 1 SFR Page = 0x0; SFR Address = 0xF2 Bit Name 7:0 P1MDIN[7:0] 2 1 0 1 1 1 Function Analog Configuration Bits for P1.7-P1.0 (respectively). Port pins configured for analog mode have their weak pullup and digital receiver disabled. The digital driver is not explicitly disabled. 0: Corresponding P1.n pin is configured for analog mode. 1: Corresponding P1.n pin is not configured for analog mode. Note: P0.7, P1.2, P1.5, P1.6 and P1.7 are internally connected to the radio peripheral. P1.0, P1.1, P1.3, P1.4, P2.2, P2.3, P2.5, and P2.6 is not externally or internally connected. SFR Definition 20.16. P1MDOUT: Port1 Output Mode Bit 7 6 5 4 3 Name P1MDOUT[7:0] Type R/W Reset 0 0 0 0 SFR Page = 0x0; SFR Address = 0xA5 Bit Name 7:0 0 2 1 0 0 0 0 Function P1MDOUT[7:0] Output Configuration Bits for P1.7-P1.0 (respectively). These bits control the digital driver even when the corresponding bit in register P1MDIN is logic 0. 0: Corresponding P1.n Output is open-drain. 1: Corresponding P1.n Output is push-pull. Note: P0.7, P1.2, P1.5, P1.6 and P1.7 are internally connected to the radio peripheral. P1.0, P1.1, P1.3, P1.4, P2.2, P2.3, P2.5, and P2.6 is not externally or internally connected. 234 Rev. 1.0 Si106x/108x SFR Definition 20.17. P1DRV: Port1 Drive Strength Bit 7 6 5 4 3 Name P1DRV[7:0] Type R/W Reset 0 0 0 0 0 SFR Page = 0xF; SFR Address = 0xA5 Bit Name 7:0 2 1 0 0 0 0 Function P1DRV[7:0] Drive Strength Configuration Bits for P1.7-P1.0 (respectively). Configures digital I/O Port cells to high or low output drive strength. 0: Corresponding P1.n Output has low output drive strength. 1: Corresponding P1.n Output has high output drive strength. Note: P0.7, P1.2, P1.5, P1.6 and P1.7 are internally connected to the radio peripheral. P1.0, P1.1, P1.3, P1.4, P2.2, P2.3, P2.5, and P2.6 is not externally or internally connected. SFR Definition 20.18. P2: Port2 Bit 7 6 5 4 Name P2[7:0] Type R/W Reset 1 1 1 1 3 2 1 0 1 1 1 1 SFR Page = All Pages; SFR Address = 0xA0; Bit-Addressable Bit Name 7:0 P2[7:0] Description Read 0: Set output latch to logic LOW. Sets the Port latch logic value or reads the Port pin 1: Set output latch to logic logic state in Port cells con- HIGH. figured for digital I/O. Port 2 Data. Rev. 1.0 Write 0: P2.n Port pin is logic LOW. 1: P2.n Port pin is logic HIGH. 235 Si106x/108x SFR Definition 20.19. P2SKIP: Port2 Skip Bit 7 6 5 4 3 Name P2SKIP[7:0] Type R/W Reset 0 0 0 0 0 2 1 0 0 0 0 SFR Page = 0x0; SFR Address = 0xD6 Bit Name 7:0 P2SKIP[7:0] Description Read Write Port 1 Crossbar Skip Enable Bits. These bits select Port 2 pins to be skipped by the Crossbar Decoder. Port pins used for analog, special functions or GPIO should be skipped by the Crossbar. 0: Corresponding P2.n pin is not skipped by the Crossbar. 1: Corresponding P2.n pin is skipped by the Crossbar. SFR Definition 20.20. P2MDIN: Port2 Input Mode Bit 7 Name Reserved 6 5 4 1 0 1 1 1 R/W 1 1 1 1 SFR Page = 0x0; SFR Address = 0xF3 Bit Name 7 6:0 2 P2MDIN[6:0] Type Reset 3 1 Function Reserved. Read = 1b; Must Write 1b. P2MDIN[3:0] Analog Configuration Bits for P2.6-P2.0 (respectively). Port pins configured for analog mode have their weak pullup and digital receiver disabled. The digital driver is not explicitly disabled. 0: Corresponding P2.n pin is configured for analog mode. 1: Corresponding P2.n pin is not configured for analog mode. 236 Rev. 1.0 Si106x/108x SFR Definition 20.21. P2MDOUT: Port2 Output Mode Bit 7 6 5 4 3 Name P2MDOUT[7:0] Type R/W Reset 0 0 0 0 0 SFR Page = 0x0; SFR Address = 0xA6 Bit Name 7:0 2 1 0 0 0 0 Function P2MDOUT[7:0] Output Configuration Bits for P2.7-P2.0 (respectively). These bits control the digital driver even when the corresponding bit in register P2MDIN is logic 0. 0: Corresponding P2.n Output is open-drain. 1: Corresponding P2.n Output is push-pull. SFR Definition 20.22. P2DRV: Port2 Drive Strength Bit 7 6 5 4 3 Name P2DRV[7:0] Type R/W Reset 0 0 0 0 SFR Page = 0x0F; SFR Address = 0xA6 Bit Name 7:0 P2DRV[7:0] 0 2 1 0 0 0 0 Function Drive Strength Configuration Bits for P2.7-P2.0 (respectively). Configures digital I/O Port cells to high or low output drive strength. 0: Corresponding P2.n Output has low output drive strength. 1: Corresponding P2.n Output has high output drive strength. Rev. 1.0 237 Si106x/108x 21. Controller Interface 21.1. Serial Interface (SPI1) The radio in the Si106x/8x communicates with the MCU over an internal 4-wire serial peripheral interface (SPI): SCLK, SDI, SDO, and nSEL. Table 21.1 shows the mapping between the MCU GPIO and the radio pins. The SPI interface is designed to operate at a maximum of 10 MHz. The SPI timing parameters are demonstrated in Table 21.2. The host MCU writes data over the SDI pin and can read data from the device on the SDO output pin. Figure 21.1 demonstrates an SPI write command. The nSEL pin should go low to initiate the SPI command. The first byte of SDI data will be one of the firmware commands followed by n bytes of parameter data which will be variable depending on the specific command. The rising edges of SCLK should be aligned with the center of the SDI data. Table 21.1. Internal Connection for Radio and MCU MCU GPIO P0.7 P1.0/SCK P1.1/MISO P1.2/MOSI P1.3/NSS Radio Control Interface SDN SCLK SDO SDI nSEL Table 21.2. Serial Interface Timing Parameters Symbol Parameter Min (ns) tCH Clock high time 40 tCL Clock low time 40 tDS Data setup time 20 tDH Data hold time 20 tDD Output data delay time 20 tEN Output enable time 20 tDE Output disable time tSS Select setup time 20 tSH Select hold time 50 tSW Select high period 80 Diagram SCLK tSS tCL tCH tDS tDH tDD tSH tDE SDI SDO 50 tEN tSW nSEL Rev. 1.0 238 Si106x/108x nSEL SDO SDI FW Command Param Byte 0 Param Byte n SCLK Figure 21.1. SPI Write Command The Si106x/8x transceiver contains an internal MCU which controls all the internal functions of the radio. For SPI read commands a typical MCU flow of checking clear-to-send (CTS) is used to make sure the internal MCU has executed the command and prepared the data to be output over the SDO pin. Figure 21.1 demonstrates the general flow of an SPI read command. Once the CTS value reads 0xFF then the read data is ready to be clocked out to the host MCU. The typical time for a valid 0xFF CTS reading is 20 s. Figure 21.3 demonstrates the remaining read cycle after CTS is set to 0xFF. The internal MCU will clock out the SDO data on the negative edge so the host MCU should process the SDO data on the rising edge of SCLK. Firmware Flow 0xFF Send Command Read CTS CTS Value 0x00 NSEL CTS SDO SDI ReadCmdBuff SCK Figure 21.2. SPI Read Command--Check CTS Value 239 Rev. 1.0 Retrieve Response Si106x/108x NSEL SDO Response Byte 0 Response Byte n SDI SCK Figure 21.3. SPI Read Command--Clock Out Read Data Rev. 1.0 240 Si106x/108x 21.2. Fast Response Registers (Si1060/61/62/63 and Si1080/81/82/83) The fast response registers are registers that can be read immediately without the requirement to monitor and check CTS. There are four fast response registers that can be programmed for a specific function. The fast response registers can be read through API commands, 0x50 for Fast Response A, 0x51 for Fast Response B, 0x53 for Fast Response C, and 0x57 for Fast Response D. The fast response registers can be configured by the "FRR_CTL_X_MODE" properties. The fast response registers may be read in a burst fashion. After the initial 16 clock cycles, each additional eight clock cycles will clock out the contents of the next fast response register in a circular fashion. The value of the FRRs will not be updated unless NSEL is toggled. 21.3. Operating Modes and Timing The primary states of the Si106x transceiver are shown in Figure 21.4. The shutdown state completely shuts down the radio to minimize current consumption. Standby/Sleep, SPI Active, Ready, TX Tune, and RX tune are available to optimize the current consumption and response time to RX/TX for a given application. API commands START_RX, START_TX, and CHANGE_STATE control the operating state with the exception of shutdown which is controlled by SDN, pin 1. Figure 21.4 shows each of the operating modes with the time required to reach either RX or TX mode as well as the current consumption of each mode. The times in Table 21.5 are measured from the rising edge of nSEL until the device is in the desired state. Note that these times are indicative of state transition timing but are not guaranteed and should only be used as a reference data point. An automatic sequencer will put the device into RX or TX from any state. It is not necessary to manually step through the states. To simplify the diagram it is not shown but any of the lower power states can be returned to automatically after RX or TX. Figure 21.4. State Machine Diagram 241 Rev. 1.0 Si106x/108x Table 21.3. Operating State Response Time and Current Consumption* Si1060/61/62/63, Si1080/81/82/83 Response Time to TX RX Current in State / Mode Shutdown State 15 ms 15 ms 30 nA Standby State Sleep State SPI Active State Ready State TX Tune State RX Tune State 440 s 440 s 340 s 126 s 58 s -- 440 s 440 s 340 s 122 s -- 74 s 50 nA 900 nA 1.35 mA 1.8 mA 8 mA 7.2 mA TX State -- 138 s 18 mA @ +10 dBm RX State 130 s 75 s 10 or 13 mA State/Mode *Note: TXRX and RXTX state transition timing can be reduced to 70 s if using Zero-IF mode. Table 21.4. Operating State Response Time and Current Consumption (Si1064/65, Si1084/85) State / Mode Response Time to Current in State / Mode Tx Rx Shutdown 30 ms 30 ms 30 nA Standby 500 s 460 s 50 nA SPI Active 500 s 330 s 1.35 mA Ready 150 s 130 s 1.8 mA Tx Tune 75 s 6.9 mA Rx Tune 75 s 6.5 mA Tx 150 s 18 mA @ +10 dBm 150 s 10 mA Rx 150 s Figure 21.5 shows the POR timing and voltage requirements. The power consumption (battery life) depends on the duty cycle of the application or how often the part is in either RX or TX state. In most applications the utilization of the standby state will be most advantageous for battery life but for very low duty cycle applications shutdown will have an advantage. For the fastest timing the next state can be selected in the START_RX or START_TX API commands to minimize SPI transactions and internal MCU processing. Rev. 1.0 242 Si106x/108x 21.3.1. Radio Power on Reset (POR) A Power On Reset (POR) sequence is used to boot the device up from a fully off or shutdown state. To execute this process, VDD must ramp within 1ms and must remain applied to the device for at least 10 ms. If VDD is removed, then it must stay below 0.15 V for at least 10 ms before being applied again. See Figure 21.5 and Table 21.5 for details. VDD VR RH VR RL Time tSR tPORH Figure 21.5. POR Timing Diagram Table 21.5. POR Timing Variable Min Typ Max Units tPORH High time for VDD to fully settle POR circuit 10 -- -- ms tPORL Low time for VDD to enable POR 10 -- -- ms VRRH Voltage for successful POR 90% x Vdd -- -- V VRRL Starting Voltage for successful POR 0 -- 150 mV Slew rate of VDD for successful POR -- -- 1 ms tSR 243 Description Rev. 1.0 Si106x/108x 21.3.2. Shutdown State The shutdown state is the lowest current consumption state of the device with nominally less than 30 nA of current consumption. The shutdown state may be entered by driving the SDN pin (Pin 1) high. The SDN pin should be held low in all states except the shutdown state. In the shutdown state, the contents of the registers are lost and there is no SPI access. When coming out of the shutdown state a power on reset (POR) will be initiated along with the internal calibrations. After the POR the POWER_UP command is required to initialize the radio. The SDN pin needs to be held high for at least 10us before driving low again so that internal capacitors can discharge. Not holding the SDN high for this period of time may cause the POR to be missed and the device to boot up incorrectly. If POR timing and voltage requirements cannot be met, it is highly recommended that SDN be controlled using the host processor rather than tying it to GND on the board. 21.3.3. Standby State Standby state has the lowest current consumption with the exception of shutdown but has much faster response time to RX or TX mode. In most cases standby should be used as the low power state. In this state the register values are maintained with all other blocks disabled. The SPI is accessible during this mode but any SPI event, including FIFO R/W, will enable an internal boot oscillator and automatically move the part to SPI active state. After an SPI event the host will need to re-command the device back to standby through the "Change State" API command to achieve the 50 nA current consumption. If an interrupt has occurred (i.e., the nIRQ pin = 0) the interrupt registers must be read to achieve the minimum current consumption of this mode. 21.3.4. Sleep State (Si1060/61/62/63 and Si1080/81/82/83) Sleep state is the same as standby state but the wake-up-timer and a 32 kHz clock source are enabled. The source of the 32 kHz clock can either be an internal 32 kHz RC oscillator which is periodically calibrated or a 32 kHz oscillator using an external XTAL.The SPI is accessible during this mode but an SPI event will enable an internal boot oscillator and automatically move the part to SPI active mode. After an SPI event the host will need to re-command the device back to sleep. If an interrupt has occurred (i.e., the nIRQ pin = 0) the interrupt registers must be read to achieve the minimum current consumption of this mode. 21.3.5. SPI Active State In SPI active state the SPI and a boot up oscillator are enabled. After SPI transactions during either standby or sleep the device will not automatically return to these states. A "Change State" API command will be required to return to either the standby or sleep modes. 21.3.6. Ready State Ready state is designed to give a fast transition time to TX or RX state with reasonable current consumption. In this mode the Crystal oscillator remains enabled reducing the time required to switch to TX or RX mode by eliminating the crystal start-up time. 21.3.7. TX State The TX state may be entered from any of the state with the "Start TX" or "Change State" API commands. A built-in sequencer takes care of all the actions required to transition between states from enabling the crystal oscillator to ramping up the PA. The following sequence of events will occur automatically when going from standby to TX state. 1. Enable internal LDOs. 2. Start up crystal oscillator and wait until ready (controlled by an internal timer). 3. Enable PLL. 4. Calibrate VCO/PLL. 5. Wait until PLL settles to required transmit frequency (controlled by an internal timer). Rev. 1.0 244 Si106x/108x 6. Activate power amplifier and wait until power ramping is completed (controlled by an internal timer). 7. Transmit packet. Steps in this sequence may be eliminated depending on which state the device is configured to prior to commanding to TX. By default, the VCO and PLL are calibrated every time the PLL is enabled. When the START_TX API command is utilized the next state may be defined to ensure optimal timing and turnaround. Figure 21.6 shows an example of the commands and timing for the START_TX command. CTS will go high as soon as the sequencer puts the part into TX state. As the sequencer is stepping through the events listed above, CTS will be low and no new commands or property changes are allowed. If the Fast Response (FRR) or nIRQ is used to monitor the current state there will be slight delay caused by the internal hardware from when the event actually occurs to when the transition occurs on the FRR or nIRQ. The time from entering TX state to when the FRR will update is 5 s and the time to when the nIRQ will transition is 13 s. If a GPIO is programmed for TX state or used as control for a transmit/receive switch (TR switch) there is no delay. CTS NSEL SDI Current State FRR START_TX YYY State Tx State YYY State TXCOMPLETE_STATE Tx State nIRQ GPIOx - TX state Figure 21.6. Start_TX Commands and Timing 245 Rev. 1.0 TXCOMPLETE_STATE Si106x/108x 21.4. Application Programming Interface (API) An application programming interface (API), which the host MCU will communicate with, is embedded inside the device. The API is divided into two sections, commands and properties. The commands are used to control the device and retrieve its status. The properties are general configurations which will change infrequently. The API descriptions for the Si1060/61/62/63 and Si1080/81/82/83 can be found in the EZRadioPRO API documentation. The API descriptions for the Si1064/65 and Si1084/85 can be found in the EZRadio API documentation. The radio in the Si106x/Si108x is capable of generating an interrupt signal when certain events occur. The radio notifies the microcontroller that an interrupt event has occurred by setting the nIRQ output pin LOW = 0. This interrupt signal will be generated when any one (or more) of the interrupt events (corresponding to the Interrupt Status bits) occur. The nIRQ pin will remain low until the microcontroller reads the Interrupt Status Registers. The nIRQ output signal will then be reset until the next change in status is detected. The interrupts sources are grouped into three groups: packet handler, device status, and modem. The individual interrupts in these groups can be enabled/disabled in the interrupt property registers, 0101, 0102, and 0103. An interrupt must be enabled for it to trigger an event on the nIRQ pin. The interrupt group must be enabled as well as the individual interrupts in API property 0100. Number Command Summary 0x20 GET_INT_STATUS Returns the interrupt status--packet handler, modem, and chip 0x21 GET_PH_STATUS Returns the packet handler status. 0x22 GET_MODEM_STATUS 0x23 GET_CHIP_STATUS Returns the modem status byte. Returns the chip status. Number Property Default Summary 0x0100 INT_CTL_ENABLE 0x04 Enables interrupt groups for PH, Modem, and Chip. 0x0101 INT_CTL_PH_ENABLE 0x00 Packet handler interrupt enable property. 0x0102 INT_CTL_MODEM_ENABLE 0x00 Modem interrupt enable property. 0x0103 INT_CTL_CHIP_ENABLE 0x04 Chip interrupt enable property. Once an interrupt event occurs and the nIRQ pin is low there are two ways to read and clear the interrupts. All of the interrupts may be read and cleared in the "GET_INT_STATUS" API command. By default all interrupts will be cleared once read. If only specific interrupts want to be read in the fastest possible method the individual interrupt groups (Packet Handler, Chip Status, Modem) may be read and cleared by the "GET_MODEM_STATUS", "GET_PH_STATUS" (packet handler), and "GET_CHIP_STATUS" API commands. The instantaneous status of a specific function maybe read if the specific interrupt is enabled or disabled. The status results are provided after the interrupts and can be read with the same commands as the interrupts. The status bits will give the current state of the function whether the interrupt is enabled or not. The fast response registers can also give information about the interrupt groups but reading the fast response registers will not clear the interrupt and reset the nIRQ pin. Rev. 1.0 246 Si106x/108x 21.5. GPIO Four general purpose IO pins are available to utilize in the application. The GPIO are configured by the GPIO_PIN_CFG command in address 13h. For a complete list of the GPIO options please see the API guide. GPIO pins 0 and 1 should be used for active signals such as data or clock. GPIO pins 2 and 3 have more susceptibility to generating spurious in the synthesizer than pins 0 and 1. The drive strength of the GPIOs can be adjusted with the GEN_CONFIG parameter in the GPIO_PIN_CFG command. By default the drive strength is set to minimum. The default configuration for the GPIOs and the state during SDN is shown below in Table 21.6.The state of the IO during shutdown is also shown in Table 21.6. As indicated previously in Table 4.20 on page 75, GPIO 0 has lower drive strength than the other GPIOs. Table 21.6. GPIOs 247 Pin SDN State POR Default GPIO0 0 POR GPIO1 0 CTS GPIO2 0 POR GPIO3 0 POR nIRQ resistive VDD pull-up nIRQ SDO resistive VDD pull-up SDO SDI High Z SDI Rev. 1.0 Si106x/108x 22. Radio 142-1050 MHz Transceiver Functional Description The Si106x/8x transceivers are high-performance, low-current, wireless MCUs that cover the sub-GHz bands. The wide operating voltage range of 1.8-3.6 V and low current consumption make the Si106x/8x an ideal solution for battery-powered applications. The Si106x operates as a time division duplexing (TDD) transceiver where the device alternately transmits and receives data packets. The device uses a singleconversion mixer to downconvert the 2/4-level FSK/GFSK or OOK modulated receive signal to a low IF frequency. Following a programmable gain amplifier (PGA) the signal is converted to the digital domain by a high performance ADC allowing filtering, demodulation, slicing, and packet handling to be performed in the built-in DSP increasing the receiver's performance and flexibility versus analog-based architectures. The demodulated signal is output to the system MCU through a programmable GPIO or via the standard SPI bus by reading the 64-byte RX FIFO. A single high precision local oscillator (LO) is used for both transmit and receive modes since the transmitter and receiver do not operate at the same time. The LO is generated by an integrated VCO and Fractional-N PLL synthesizer. The synthesizer is designed to support configurable data rates. The Si1060/61/62/63 and Si1080/81/82/83 operate in the frequency bands of 142-175, 283-350, 420-525, and 850-1050 MHz with a maximum frequency accuracy step size of 28.6 Hz and data rates from 100 bps to 1 Mbps. The Si1064/65/Si1084/85 operates in the frequency bands of 283-350, 425-525 and 850- 960 MHz with a maximum frequency accuracy step size of 114.4 Hz, and a data rate from 1 to 500 kbps. The Si1060/61/80/81 contains a power amplifier (PA) that supports output power up to +20 dBm with very high efficiency, consuming only 70 mA at 169 MHz and 85 mA at 915 MHz. The integrated +20 dBm power amplifier can also be used to compensate for the reduced performance of a lower cost, lower performance antenna or antenna with size constraints due to a small form factor. Competing solutions require expensive external PAs to achieve comparable performance. The Si1062/63/64/65/Si1082/83/84/85 is designed to support single cell operation with current consumption below 18 mA for +10 dBm output power. Two match topologies are available for the Si1062-65/Si1082-85, class-E and switched-current. Class-E matching provides optimal current consumption, while switched-current matching demonstrates the best performance over varying battery voltage and temperature with slightly higher current consumption. The PA is singleended to allow for easy antenna matching and low BOM cost. The PA incorporates automatic ramp-up and ramp-down control to reduce unwanted spectral spreading. The Si106x/8x family supports frequency hopping, TX/RX switch control, and antenna diversity switch control to extend the link range and improve performance. Built-in antenna diversity and support for frequency hopping can be used to further extend range and enhance performance. Antenna diversity is completely integrated into the Si1060-63, Si108083 and can improve the system link budget by 8-10 dB, resulting in substantial range increases under adverse environmental conditions. A highly configurable packet handler allows for autonomous encoding/decoding of nearly any packet structure. Additional system features, such as an automatic wake-up timer, 64 byte TX/RX FIFOs, and preamble detection, reduce overall current consumption and allows for the use of lower-cost system MCUs. The Si106x/8x is designed to work with a crystal, and a few passive components to create a very low-cost system. Rev. 1.0 248 Si106x/108x 23. Modulation and Hardware Configuration Options The Si106x/8x supports different modulation options and can be used in various configurations to tailor the device to any specific application or legacy system for drop in replacement. The modulation and configuration options are set in the API. For more information on the API commands, refer to the EZRadioPRO API document for the Si1060-Si1063/Si1080-Si1083 and the EZRadio API Guide for the Si1064/65/84/85. 23.1. Modulation Types The Si106x/8x supports up to five different modulation options: On-off keying (OOK), Gaussian frequency shift keying (GFSK), frequency-shift keying (FSK), as well as four-level GFSK (4GFSK), and four-level FSK (4FSK) for the Si1060-Si1063 devices. Minimum shift keying (MSK) can also be created by using GFSK settings. GFSK is the recommended modulation type as it provides the best performance and cleanest modulation spectrum. The modulation type is set by the API. A continuous-wave (CW) carrier may also be selected for RF evaluation purposes. The modulation source may also be selected to be a pseudo-random source for evaluation purposes. 23.2. Hardware Configuration Options There are different receive demodulator options to optimize the performance and mutually-exclusive options for how the RX/TX data is transferred from the host MCU to the RF device. 23.2.1. Receive Demodulator Options There are multiple demodulators integrated into the device to optimize the performance for different applications, modulation formats, and packet structures. The calculator built into WDS will choose the optimal demodulator based on the input criteria. 23.2.1.1. Synchronous Demodulator The synchronous demodulator's internal frequency error estimator acquires the frequency error based on a 101010 preamble structure. The bit clock recovery circuit locks to the incoming data stream within four transactions of a "10" or "01" bit stream. The synchronous demodulator gives optimal performance for 2- or 4-level FSK or GFSK modulation that has a modulation index less than 2. 23.2.1.2. Asynchronous Demodulator The asynchronous demodulator should be used OOK modulation and for FSK/GFSK/4GFSK under one or more of the following conditions: Modulation index > 2 Non-standard preamble (not 1010101... pattern) When the modulation index exceeds 2, the asynchronous demodulator has better sensitivity compared to the synchronous demodulator. An internal deglitch circuit provides a glitch-free data output and a data clock signal to simplify the interface to the host. There is no requirement to perform deglitching in the host MCU. The asynchronous demodulator will typically be utilized for legacy systems and will have many performance benefits over devices used in legacy designs. Unlike the Si100x/Si101x solution for non-standard packet structures, there is no requirement to perform deglitching on the data in the host MCU. Glitchfree data is output from Si106x/8x devices, and a sample clock for the asynchronous data can also be supplied to the host MCU; so, oversampling or bit clock recovery is not required by the host MCU. There are multiple detector options in the asynchronous demodulator block, which will be selected based upon the options entered into the WDS calculator. The asynchronous demodulator's internal frequency error estimator is able to acquire the frequency error based on any preamble structure. 249 Rev. 1.0 Si106x/108x 23.2.2. RX/TX Data Interface With MCU There are two different options for transferring the data from the RF device to the host MCU. FIFO mode uses the SPI interface to transfer the data, while direct mode transfers the data in real time over GPIO. 23.2.2.1. FIFO Mode In FIFO mode, the transmit and receive data is stored in integrated FIFO register memory. The TX FIFO is accessed by writing Command 66h followed directly by the data/clk that the host wants to write into the TX FIFO. The RX FIFO is accessed by writing command 77h followed by the number of clock cycles of data the host would like to read out of the RX FIFO. The RX data will be clocked out onto the SDO pin. In TX mode, if the packet handler is enabled, the data bytes stored in FIFO memory are "packaged" together with other fields and bytes of information to construct the final transmit packet structure. These other potential fields include the Preamble, Sync word, Header, CRC checksum, etc. The configuration of the packet structure in TX mode is determined by the Automatic Packet Handler (if enabled), in conjunction with a variety of Packet Handler properties. If the Automatic Packet Handler is disabled, the entire desired packet structure should be loaded into FIFO memory; no other fields (such as Preamble or Sync word) will be automatically added to the bytes stored in FIFO memory. For further information on the configuration of the FIFOs for a specific application or packet size, see Section "25. Data Handling and Packet Handler" on page 262. In RX mode, only the bytes of the received packet structure that are considered to be "data bytes" are stored in FIFO memory. Which bytes of the received packet are considered "data bytes" is determined by the Automatic Packet Handler (if enabled) in conjunction with the Packet Handler configuration. If the Automatic Packet Handler is disabled, all bytes following the Sync word are considered data bytes and are stored in FIFO memory. Thus, even if Automatic Packet Handling operation is not desired, the preamble detection threshold and Sync word still need to be programmed so that the RX Modem knows when to start filling data into the FIFO. When the FIFO is being used in RX mode, all of the received data may still be observed directly (in realtime) by properly programming a GPIO pin as the RXDATA output pin; this can be quite useful during application development. When in FIFO mode, the chip will automatically exit the TX or RX State when either the PACKET_SENT or PACKET_RX interrupt occurs. The chip will return to the IDLE state programmed in the API. 23.2.2.2. Direct Mode (Si1060-Si1063, Si1080-Si1083) For legacy systems that perform packet handling within the host MCU or other baseband chip, it may not be desirable to use the FIFO. For this scenario, a Direct mode is provided, which bypasses the FIFOs entirely. In TX Direct mode, the TX modulation data is applied to an input pin of the chip and processed in "real time" (i.e., not stored in a register for transmission at a later time). Any of the GPIOs may be configured for use as the TX Data input function. Furthermore, an additional pin may be required for a TX Clock output function if GFSK modulation is desired (only the TX Data input pin is required for FSK). To achieve direct mode, the GPIO must be configured in the API. 23.3. Preamble Length The preamble length requirement is only relevant if using the synchronous demodulator. If the asynchronous demodulator is being used, then there is no requirement for a conventional 101010 pattern. The preamble detection threshold determines the number of valid preamble bits the radio must receive to qualify a valid preamble. The preamble threshold should be adjusted depending on the nature of the application. The required preamble length threshold depends on when receive mode is entered in relation to the start of the transmitted packet and the length of the transmit preamble. With a shorter than recommended preamble detection threshold, the probability of false detection is directly related to how long the receiver operates on noise before the transmit preamble is received. False detection on noise may cause the actual packet to be missed. The preamble detection threshold may be adjusted in the modem calculator by modifying the "PM detection threshold" in the "RX parameters tab" in the radio control panel. For most applications with a preamble length longer than 32 bits, the default value of 20 is recommended for the preamble detection threshold. A shorter Preamble Detection Threshold may be chosen if occasional false detections Rev. 1.0 250 Si106x/108x may be tolerated. When antenna diversity is enabled, a 20-bit preamble detection threshold is recommended. When the receiver is synchronously enabled just before the start of the packet, a shorter preamble detection threshold may be used. Table 23.1 demonstrates the recommended preamble detection threshold and preamble length for various modes. Table 23.1. Recommended Preamble Length Mode AFC Antenna Diversity Preamble Type Recommended Preamble Length Recommended Preamble Detection Threshold (G)FSK Disabled Disabled Standard 4 Bytes 20 bits (G)FSK Enabled Disabled Standard 5 Bytes 20 bits (G)FSK Disabled Disabled Non-standard 2 Bytes 0 bits (G)FSK Enabled (G)FSK Disabled Enabled Standard 7 Bytes 24 bits (G)FSK Enabled Enabled Standard 8 Bytes 24 bits 4(G)FSK Disabled Disabled Standard 40 symbols 16 symbols 4(G)FSK Enabled Disabled Standard 48 symbols 16 symbols Non-standard 4(G)FSK Not Supported Non-standard Not Supported OOK Disabled Disabled Standard 4 Bytes 20 bits OOK Disabled Disabled Non-standard 2 Bytes 0 bits OOK Enabled Not Supported Notes: 1. The recommended preamble length and preamble detection thresholds listed above are to achieve 0% PER. They may be shortened when occasional packet errors are tolerable. 2. All recommended preamble lengths and detection thresholds include AGC and BCR settling times. 3. "Standard" preamble type should be set for an alternating data sequence at the max data rate (...10101010...) 4. "Non-standard" preamble type can be set for any preamble type including ...10101010... 5. When preamble detection threshold = 0, sync word needs to be 3 Bytes to avoid false syncs. When only a 2 Byte sync word is available the sync word detection can be extended by including the last preamble Byte into the RX sync word setting. 251 Rev. 1.0 Si106x/108x 24. Internal Functional Blocks The following sections provide an overview to the key internal blocks and features. 24.1. RX Chain The internal low-noise amplifier (LNA) is designed to be a wide-band LNA that can be matched with three external discrete components to cover any common range of frequencies in the sub-GHz band. The LNA has extremely low noise to suppress the noise of the following stages and achieve optimal sensitivity; so, no external gain or front-end modules are necessary. The LNA has gain control, which is controlled by the internal automatic gain control (AGC) algorithm. The LNA is followed by an I-Q mixer, filter, programmable gain amplifier (PGA), and ADC. The I-Q mixers downconvert the signal to an intermediate frequency. The PGA then boosts the gain to be within dynamic range of the ADC. The ADC rejects out-of-band blockers and converts the signal to the digital domain where filtering, demodulation, and processing is performed. Peak detectors are integrated at the output of the LNA and PGA for use in the AGC algorithm. The RX and TX pins maybe directly tied externally for output powers less than +17 dBm, see the direct-tie reference designs on the Silicon Labs web site for more details. 24.1.1. RX Chain Architecture It is possible to operate the RX chain in different architecture configurations: fixed-IF, zero-IF, scaled-IF, and modulated IF (Si1064/65 and Si1084/85 support fixed-IF only). There are trade-offs between the architectures in terms of sensitivity, selectivity, and image rejection. Fixed-IF is the default configuration and is recommended for most applications. With 35 dB native image rejection and autonomous image calibration to achieve 55 dB, the fixed-IF solution gives the best performance for most applications. Fixed-IF obtains the best sensitivity, but it has the effect of degraded selectivity at the image frequency. An autonomous image rejection calibration is included in Si1060-Si1063/Si1080-Si1083 devices and described in more detail in Section "24.2.3. Image Rejection and Calibration (Si1060-Si1063, Si1080-S1083)" on page 254. For fixed-IF and zero-IF, the sensitivity is degraded for data rates less than 100 kbps or bandwidths less than 200 kHz. The reduction in sensitivity is caused by increased flicker noise as dc is approached. The benefit of zero-IF is that there is no image frequency; so, there is no degradation in the selectivity curve, but it has the worst sensitivity. Scaled-IF is a trade-off between fixed-IF and zero-IF. In the scaled-IF architecture, the image frequency is placed or hidden in the adjacent channel where it only slightly degrades the typical adjacent channel selectivity. The scaled-IF approach has better sensitivity than zero-IF but still some degradation in selectivity due to the image. In scaled-IF mode, the image frequency is directly proportional to the channel bandwidth selected. Figure 24.1 demonstrates the trade-off in sensitivity between the different architecture options. Rev. 1.0 252 Si106x/108x 1% PER sensitivity vs. data rate (h=1) -95 Sensitivity (dBm) -100 -105 Fixed IF Scaled IF -110 Zero IF -115 -120 1 10 100 Data rate (kbps) Figure 24.1. RX Architecture vs. Data Rate 24.2. RX Modem Using high-performance ADCs allows channel filtering, image rejection, and demodulation to be performed in the digital domain, which allows for flexibility in optimizing the device for particular applications. The digital modem performs the following functions: Channel selection filter TX modulation RX demodulation Automatic Gain Control (AGC) Preamble detection Invalid preamble detection Radio signal strength indicator (RSSI) Automatic frequency compensation (AFC) Image Rejection Calibration (Si1060-Si1063, Si1080-Si1083) Packet handling Cyclic redundancy check (CRC) The digital channel filter and demodulator are optimized for ultra-low-power consumption and are highly configurable. Supported modulation types are OOK, GFSK, FSK, GMSK as well as 4FSK/4GFSK for the Si1060-Si1063. The channel filter can be configured to support bandwidths ranging from 850 down to 1.1 kHz on the Si1060-Si1063/Si1080-Si1083. A large variety of data rates are supported ranging from 100 bps up to 1 Mbps. The configurable preamble detector is used with the synchronous demodulator to improve the reliability of the sync-word detection. Preamble detection can be skipped using only sync detection, which is a valuable feature of the asynchronous demodulator when very short preambles are used in protocols, such as MBus. The received signal strength indicator (RSSI) provides a measure of the signal strength received on the tuned channel. The resolution of the RSSI is 0.5 dB. This high-resolution RSSI enables accurate channel power measurements for clear channel assessment (CCA), carrier sense (CS), and listen before talk (LBT) functionality. The extensive programmability of the packet header allows 253 Rev. 1.0 Si106x/108x for advanced packet filtering, which, in turn enables a mix of broadcast, group, and point-to-point communication. A wireless communication channel can be corrupted by noise and interference, so it is important to know if the received data is free of errors. A cyclic redundancy check (CRC) is used to detect the presence of erroneous bits in each packet. A CRC is computed and appended at the end of each transmitted packet and verified by the receiver to confirm that no errors have occurred. The packet handler and CRC can significantly reduce the load on the system microcontroller allowing for a simpler and cheaper microcontroller. The digital modem includes the TX modulator, which converts the TX data bits into the corresponding stream of digital modulation values to be summed with the fractional input to the sigma-delta modulator. This modulation approach results in highly accurate resolution of the frequency deviation. A Gaussian filter is implemented to support GFSK and 4GFSK, considerably reducing the energy in adjacent channels. The default bandwidth-time product (BT) is 0.5 for all programmed data rates, but it may be adjusted to other values. 24.2.1. Automatic Gain Control (AGC) The AGC algorithm is implemented digitally using an advanced control loop optimized for fast response time. The AGC occurs within a single bit or in less than 2 s. Peak detectors at the output of the LNA and PGA allow for optimal adjustment of the LNA gain and PGA gain to optimize IM3, selectivity, and sensitivity performance. 24.2.2. Auto Frequency Correction (AFC) Frequency mistuning caused by crystal inaccuracies can be compensated for by enabling the digital automatic frequency control (AFC) in receive mode. There are two types of integrated frequency compensation: modem frequency compensation, and AFC by adjusting the PLL frequency. With AFC disabled, the modem compensation can correct for frequency offsets up to 0.25 times the IF bandwidth. When the AFC is enabled, the received signal will be centered in the pass-band of the IF filter, providing optimal sensitivity and selectivity over a wider range of frequency offsets up to 0.35 times the IF bandwidth. When AFC is enabled, the preamble length needs to be long enough to settle the AFC. As shown in Table 23.1 on page 251, an additional byte of preamble is typically required to settle the AFC. 24.2.3. Image Rejection and Calibration (Si1060-Si1063, Si1080-S1083) Since the receiver utilizes a low-IF architecture, the selectivity will be affected by the image frequency. The IF frequency is 468.75 kHz (Fxtal/64), and the image frequency will be at 937.5 kHz below the RF frequency. The native image rejection of the Si106x/8x family is 35 dB. Image rejection calibration is available in the Si106x/8x to improve the image rejection to more than 55 dB. The calibration is initiated with the IRCAL API command. The calibration uses an internal signal source, so no external signal generator is required. The initial calibration takes 250 ms, and periodic re-calibration takes 100 ms. Re-calibration should be initiated when the temperature has changed more than 30 C. 24.2.4. Received Signal Strength Indicator The received signal strength indicator (RSSI) is an estimate of the signal strength in the channel to which the receiver is tuned. The RSSI measurement is done after the channel filter, so it is only a measurement of the desired or undesired in-band signal power. There are two different methods for reading the RSSI value and several different options for configuring the RSSI value that is returned. The fastest method for reading the RSSI is to configure one of the four fast response registers (FRR) to return a latched RSSI value. The latched RSSI value is measured once per packet and is latched at a configurable amount of time after RX mode is entered. The fast response registers can be read in 16 SPI clock cycles with no requirement to wait for CTS. The RSSI value may also be read out of the GET_MODEM_STATUS command. In this command, both the current RSSI and the latched RSSI are available. The current RSSI value represents the signal strength at the instant in time the GET_MODEM_STATUS command is processed and may be read multiple times per packet. Reading the RSSI in the GET_MODEM_STATUS command takes longer than reading the RSSI out of the fast response register. After the initial command, it will take 33 s for CTS to be set and then the four or five bytes of SPI clock cycles to read out the respective current or latched RSSI values. Rev. 1.0 254 Si106x/108x The RSSI configuration options are set in the MODEM_RSSI_CONTROL API property. The latched RSSI value may be latched and stored based on the following events: preamble detection, sync detection, or a configurable number of bit times measured after the start of RX mode (minimum of 4 bit times). The requirement for four bit times is determined by the processing delay and settling through the modem and digital channel filter. In MODEM_RSSI_CONTROL, the RSSI may be defined to update every bit period or to be averaged and updated every four bit periods. If RSSI averaging over four bits is enabled, the latched RSSI value will be delayed to a minimum of 7 bits after the start of RX mode to allow for the averaging. The latched RSSI values are cleared when entering RX mode so they may be read after the packet is received or after dropping back to standby mode. If the RSSI value has been cleared by the start of RX but not latched yet, a value of 0 will be returned if it is attempted to be read. The RSSI value read by the API could be translated to dBm by the following linear equation: RSSI (in dBm) = (RSSI_value /2) - RSSIcal RSSIcal in the above formula depends on the matching network, modem settings, and external LNA gain (if present). The RSSIcal value can be obtained by a simple calibration with a signal generator connected at the antenna input. Without external LNA, the value of RSSIcal is around 130 30. During packet reception, it may be useful to detect whether a secondary interfering signal (desired or undesired) arrives. To detect this event, a feature for RSSI jump detection is available. If the RSSI level changes by a programmable amount during the reception of a packet, an interrupt or GPIO can be configured to notify the host. The level of RSSI increase or decrease (jump) is programmable through the MODEM_RSSI_JUMP_THRESH API property. If an RSSI jump is detected, the modem may be programmed to automatically reset so that it may lock onto the new stronger signal. The chip may also be configured to automatically reset the receiver upon jump detection in order to acquire the new signal. The configuration and options for RSSI jump detection are programmed in the MODEM_RSSI_CONTROL2 API property. By default, RSSI jump detection is not enabled. The RSSI values and curves may be offset by the MODEM_RSSI_COMP API property. The default value of 7'h32 corresponds to no RSSI offset. Setting a value less than 7'h32 corresponds to a negative offset, and a value higher than 7'h32 corresponds to a positive offset. The offset value is in 1 dB steps. For example, setting a value of 7'h3A corresponds to a positive offset of 8 dB. Clear channel assessment (CCA) or RSSI threshold detection is also available. An RSSI threshold may be set in the MODEM_RSSI_THRESH API property. If the RSSI value is above this threshold, an interrupt or GPIO may notify the host. Both the latched version and asynchronous version of this threshold are available on any of the GPIOs. Automatic fast hopping based on RSSI is available. See Section "24.3.1.2. Automatic RX Hopping and Hop Table" on page 256. 24.3. Synthesizer An integrated Sigma Delta () Fractional-N PLL synthesizer capable of operating over the bands from 142-175, 283-350, 420-525, and 850-1050 MHz for the Si1060-Si1063/Si1080-Si1083. Using a synthesizer has many advantages; it provides flexibility in choosing data rate, deviation, channel frequency, and channel spacing. The transmit modulation is applied directly to the loop in the digital domain through the fractional divider, which results in very precise accuracy and control over the transmit deviation. The frequency resolution in the 850-1050 MHz band is 28.6 Hz with more resolution in the other bands. The nominal reference frequency to the PLL is 30 MHz, but any XTAL frequency from 25 to 32 MHz may be used. The modem configuration calculator in WDS will automatically account for the XTAL frequency being used. The PLL utilizes a differential LC VCO with integrated on-chip inductors. The output of the VCO is followed by a configurable divider, which will divide the signal down to the desired output frequency band. 255 Rev. 1.0 Si106x/108x 24.3.1. Synthesizer Frequency Control The frequency is set by changing the integer and fractional settings to the synthesizer. The WDS calculator will automatically provide these settings, but the synthesizer equation is shown below for convenience. The APIs for setting the frequency are FREQ_CONTROL_INTE, FREQ_CONTROL_FRAC2, FREQ_CONTROL_FRAC1, and FREQ_CONTROL_FRAC0. Note: The fc_frac/219 value in the above formula has to be a number between 1 and 2. Table 24.1. Output Divider (Outdiv) Values for the Si1060-Si1063, Si1080-1083 Outdiv Lower (MHz) Upper (MHz) 24 142 175 12 284 350 8 420 525 4 850 1050 Table 24.2. Output Divider (Outdiv) for the Si1064/Si1065/Si1084/Si1085 Outdiv Lower (MHz) Upper (MHz) 12 284 350 8 425 525 4 850 960 24.3.1.1. EZ Frequency Programming In applications that utilize multiple frequencies or channels, it may not be desirable to write four API registers each time a frequency change is required. EZ frequency programming is provided so that only a single register write (channel number) is required to change frequency. A base frequency is first set by first programming the integer and fractional components of the synthesizer. This base frequency will correspond to channel 0. Next, a channel step size is programmed into the API registers. The resulting frequency will be RF Frequency = Base Frequency + Channel Step Size: The second argument of the START_RX or START_TX is CHANNEL, which sets the channel number for EZ frequency programming. For example, if the channel step size is set to 1 MHz, the base frequency is set to 900 MHz with the INTE and FRAC API registers, and a CHANNEL number of 5 is programmed during the START_TX command, the resulting frequency will be 905 MHz. If no CHANNEL argument is written as part of the START_RX/TX command, it will default to the previous value. The initial value of CHANNEL is 0; so, if no CHANNEL value is written, it will result in the programmed base frequency. 24.3.1.2. Automatic RX Hopping and Hop Table The transceiver supports an automatic hopping feature that can be fully configured through the API. This is intended for RX hopping where the device has to hop from channel to channel and look for packets. Once the device is put into the RX state, it automatically starts hopping through the hop table if the feature is enabled. The hop table can hold up to 64 entries and is maintained in firmware. Each entry is a channel number; so, the hop table can hold up to 64 channels. The number of entries in the table is set by RX HOP TABLE_SIZE API. The specified channels correspond to the EZ frequency programming method for programming the frequency. The receiver starts at the base channel and hops in sequence from the top of the hop table to the bottom. The table will wrap around to the base channel once it reaches the end of the table. An entry of 0xFF in the table indicates that the entry should be skipped. The device will hop to the next non 0xFF entry. Rev. 1.0 256 Si106x/108x There are three conditions that can be used to determine whether to continue hopping or to stay on a particular channel. These conditions are: RSSI threshold Preamble timeout (invalid preamble pattern) Sync word timeout (invalid or no sync word detected after preamble) These conditions can be used individually, or they can be enabled all together by configuring the RX_HOP_CONTROL API. However, the firmware will make a decision on whether or not to hop based on the first condition that is met. The RSSI that is monitored is the current RSSI value. This is compared to the threshold, and, if it is above the threshold value, it will stay on the channel. If the RSSI is below the threshold, it will continue hopping. There is no averaging of RSSI done during the automatic hopping from channel to channel. Since the preamble timeout and the sync word timeout are features that require packet handling, the RSSI threshold is the only condition that can be used if the user is in "direct" or "RAW" mode where packet handling features are not used. Note that the RSSI threshold is not an absolute RSSI value; instead, it is a relative value and should be verified on the bench to find an optimal threshold for the application. The turnaround time from RX to RX on a different channel using this method is 115 s. The time spent in receive mode will be determined by the configuration of the hop conditions. Manual RX hopping will have the fastest turn-around time but will require more overhead and management by the host MCU. The following are example steps for using Auto Hop: 1. Set the base frequency (inte + frac) and channel step size. 2. Define the number of entries in the hop table (RX_HOP_TABLE_SIZE). 3. Write the channels to the hop table (RX_HOP_TABLE_ENTRY_n) 4. Configure the hop condition and enable auto hopping- RSSI, preamble, or sync (RX_HOP_CONTROL). 5. Set preamble and sync parameters if enabled. 6. Program the RSSI threshold property in the modem using "MODEM_RSSI_THRESH". 7. Set the preamble threshold using "PREAMBLE_CONFIG_STD_1". 8. Program the preamble timeout property using "PREAMBLE_CONFIG_STD_2". 9. Set the sync detection parameters if enabled. 10.If needed, use "GPIO_PIN_CFG" to configure a GPIO to toggle on hop and hop table wrap. 11. Use the "START_RX" API with channel number set to the first valid entry in the hop table (i.e., the first non 0xFF entry). 12.Device should now be in auto hop mode. 257 Rev. 1.0 Si106x/108x 24.3.1.3. Manual RX Hopping The RX_HOP command provides the fastest method for hopping from RX to RX but it requires more overhead and management by the host MCU. Using the RX_HOP command, the turn-around time is 75 s. The timing is faster with this method than Start_RX or RX hopping because one of the calculations required for the synthesizer calibrations is offloaded to the host and must be calculated/stored by the host, VCO_CNT0. For information about using fast manual hopping, contact customer support. 24.4. Transmitter (TX) The Si1060/Si1061/Si1080/Si1081 contains an integrated +20 dBm transmitter or power amplifier that is capable of transmitting from -20 to +20 dBm. The output power steps are less than 0.25 dB within 6 dB of max power but become larger and more non-linear close to minimum output power. The PA is designed to provide the highest efficiency and lowest current consumption possible. The Si1062-Si1065/Si1082Si1085 is designed to supply +10 dBm output power for less than 20 mA for applications that require operation from a single coin cell battery. The Si1062-Si1065/Si1082-Si1085 can also operate with either classE or switched current matching and output up to +13 dBm TX power. All PA options are single-ended to allow for easy antenna matching and low BOM cost. Automatic ramp-up and ramp-down is performed to reduce unwanted spectral spreading. The Si1060-Si1063/Si1080-Si1083 TXRAMP pin is disabled by default to save current in cases where onchip PA will be able to drive the antenna. In cases where on-chip PA will drive the external PA, and the external PA needs a ramping signal, TXRAMP is the signal to use. TXRAMP will start to ramp up, and ramp down at the same time as the internal on-chip PA ramps up/down. The ramping speed is programmed by TC[3:0] in the PA_RAMP_EX API property, which has the following characteristics: TC Ramp Time (s) 0.0 2.0 1.0 2.1 2.0 2.2 3.0 2.4 4.0 2.6 5.0 2.8 6.0 3.1 7.0 3.4 8.0 3.7 9.0 4.1 10.0 4.5 11.0 5.0 12.0 6.0 13.0 8.0 14.0 10.0 15.0 20.0 The ramping profile is close to a linear ramping profile with smoothed out corner when approaching Vhi and Vlo. The TXRAMP pin can source up to 1 mA without voltage drooping. Rev. 1.0 258 Si106x/108x The TXRAMP pin's sinking capability is equivalent to a 10 k pull-down resistor. Vhi = 3 V when Vdd > 3.3 V. When Vdd < 3.3 V, the Vhi will be closely following the Vdd, and ramping time will be smaller also. Vlo = 0 V when no current needs to be sunk into the TXRAMP pin. If 10 A needs to be sunk into the chip, Vlo will be 10 A x 10k = 100 mV. Number Command Summary 0x2200 PA_MODE 0x2201 PA_PWR_LVL 0x2202 PA_BIAS_CLKDUTY Adjust TX power in coarse steps and optimizes for different match configurations. 0x2203 PA_TC Changes the ramp up/down time of the PA. Sets PA type. Adjust TX power in fine steps. 24.4.1. Si1060/Si1061/Si1080/Si1081: +20 dBm PA The +20 dBm configuration utilizes a class-E matching configuration. Typical performance for the 900 MHz band for output power steps, voltage, and temperature are shown in Figure 24.2-Figure 24.4. The output power is changed in 128 steps through PA_PWR_LVL API. For detailed matching values, BOM, and performance at other frequencies, refer to the PA Matching application note. TX Power(dBm) TX Power vs. PA_PWR_LVL 25 20 15 10 5 0 -5 -10 -15 -20 -25 -30 -35 0 10 20 30 40 50 60 70 80 90 100 110 120 PA_PWR_LVL Figure 24.2. +20 dBm TX Power vs. PA_PWR_LVL 259 Rev. 1.0 Si106x/108x TX Power vs. VDD TX Power (dBm) 22 20 18 16 14 12 10 1.8 2 2.2 2.4 2.6 2.8 3 3.2 3.4 3.6 Supply Voltage (VDD) Figure 24.3. +20 dBm TX Power vs. VDD TX Power vs Temp TX Power (dBm) 20.5 20 19.5 19 18.5 18 -40 -30 -20 -10 0 10 20 30 40 50 60 70 80 Temperature (C) Figure 24.4. +20 dBm TX Power vs. Temp Rev. 1.0 260 Si106x/108x 24.5. Crystal Oscillator The Si106x/8x includes an integrated crystal oscillator with a fast start-up time of less than 250 s. The design is differential with the required crystal load capacitance integrated on-chip to minimize the number of external components. By default, all that is required off-chip is the crystal. The default crystal is 30 MHz, but the circuit is designed to handle any crystal from 25 to 32 MHz. If a crystal different than 30 MHz is used, the POWER_UP API boot command must be modified. The WDS calculator crystal frequency field must also be changed to reflect the frequency being used. The crystal load capacitance can be digitally programmed to accommodate crystals with various load capacitance requirements and to adjust the frequency of the crystal oscillator. The tuning of the crystal load capacitance is programmed through the GLOBAL_XO_TUNE API property. The total internal capacitance is 11 pF and is adjustable in 127 steps (70 fF/step). The crystal frequency adjustment can be used to compensate for crystal production tolerances. The frequency offset characteristics of the capacitor bank are demonstrated in Figure 24.5. Figure 24.5. Capacitor Bank Frequency Offset Characteristics A TCXO or external signal source can easily be used in place of a conventional XTAL and should be connected to the XIN pin. The incoming clock signal is recommended to have a peak-to-peak swing in the range of 600 mV to 1.4 V and ac-coupled to the XIN pin. If the peak-to-peak swing of the TCXO exceeds 1.4 V peak-to-peak, then dc coupling to the XIN pin should be used. The maximum allowed swing on XIN is 1.8 V peak-to-peak. The XO capacitor bank should be set to 0 whenever an external drive is used on the XIN pin. In addition, the POWER_UP command should be invoked with the TCXO option whenever external drive is used. 261 Rev. 1.0 Si106x/108x 25. Data Handling and Packet Handler 25.1. RX and TX FIFOs Two 64-byte FIFOs are integrated into the Si106x/8x, one for RX and one for TX, as shown in Figure 25.1. Writing to command Register 66h loads data into the TX FIFO, and reading from command Register 77h reads data from the RX FIFO. The TX FIFO has a threshold for when the FIFO is almost empty, which is set by the "TX_FIFO_EMPTY" property. An interrupt event occurs when the data in the TX FIFO reaches the almost empty threshold. If more data is not loaded into the FIFO, the chip automatically exits the TX state after the PACKET_SENT interrupt occurs. The RX FIFO has one programmable threshold, which is programmed by setting the "RX_FIFO_FULL" property. When the incoming RX data crosses the Almost Full Threshold, an interrupt will be generated to the microcontroller via the nIRQ pin. The microcontroller will then need to read the data from the RX FIFO. The RX Almost Full Threshold indication implies that the host can read at least the threshold number of bytes from the RX FIFO at that time. Both the TX and RX FIFOs may be cleared or reset with the "FIFO_RESET" command. RX FIFO TX FIFO RX FIFO Almost Full Threshold TX FIFO Almost Empty Threshold Figure 25.1. TX and RX FIFOs 25.2. Packet Handler Config 0, 2, or 4 Bytes Con fig 0, 2, or 4 Bytes Config 0, 2, or 4 B ytes C RC Field 5 (opt) Field 5 (opt) Data C RC Field 4 (opt) Field 4 (opt) Data C RC Field 3 (opt) Field 3 (opt) Data Con fig C RC Field 2 (opt) 1-4 Bytes Field 2 (opt) Pkt Len gth or Data Field 1 Header or Data 1-255 Bytes C RC Field 1 (opt) Preamble Sync Word When using the FIFOs, automatic packet handling may be enabled for TX mode, RX mode, or both. The usual fields for network communication, such as preamble, synchronization word, headers, packet length, and CRC, can be configured to be automatically added to the data payload. The fields needed for packet generation normally change infrequently and can therefore be stored in registers. Automatically adding these fields to the data payload in TX mode and automatically checking them in RX mode greatly reduces the amount of communication between the microcontroller and Si106x. It also greatly reduces the required computational power of the microcontroller. The general packet structure is shown in Figure 25.2. Any or all of the fields can be enabled and checked by the internal packet handler. Con fig 0, 2, or 4 Bytes 0, 2, or 4 Bytes Figure 25.2. Packet Handler Structure Rev. 1.0 262 Si106x/108x The fields are highly programmable and can be used to check any kind of pattern in a packet structure. The general functions of the packet handler include the following: Detection/validation of Preamble quality in RX mode (PREAMBLE_VALID signal) Detection of Sync word in RX mode (SYNC_OK signal) Detection of valid packets in RX mode (PKT_VALID signal) Detection of CRC errors in RX mode (CRC_ERR signal) Data de-whitening and/or Manchester decoding (if enabled) in RX mode Match/Header checking in RX mode Storage of Data Field bytes into FIFO memory in RX mode Construction of Preamble field in TX mode Construction of Sync field in TX mode Construction of Data Field from FIFO memory in TX mode Construction of CRC field (if enabled) in TX mode Data whitening and/or Manchester encoding (if enabled) in TX mode For details on how to configure the packet handler, see "AN626: Packet Handler Operation for Si106x RFICs". 26. RX Modem Configuration The Si106x/8x can easily be configured for different data rate, deviation, frequency, etc. by using the WDS settings calculator, which generates an example file for use by the host MCU. 27. Auxiliary Blocks 27.1. Wake-Up Timer and 32 kHz Clock Source The chip contains an integrated wake-up timer that can be used to periodically wake the chip from sleep mode. The wake-up timer runs from either the internal 32 kHz RC Oscillator, or from an external 32 kHz crystal. The wake-up timer can be configured to run when in sleep mode. If WUT_EN = 1 in the GLOBAL_WUT_CONFIG property, prior to entering sleep mode, the wake-up timer will count for a time specified defined by the GLOBAL_WUT_R and GLOBAL_WUT_M properties. At the expiration of this period, an interrupt will be generated on the nIRQ pin if this interrupt is enabled in the INT_CTL_CHIP_ENABLE property. The microcontroller will then need to verify the interrupt by reading the chip interrupt status either via GET_INT_STATUS or a fast response register. The formula for calculating the Wake-Up Period is as follows: WUT_R 42 WUT = WUT_M ---------------------------- ms 32 768 The RC oscillator frequency will change with temperature; so, a periodic recalibration is required. The RC oscillator is automatically calibrated during the POWER_UP command and exits from the Shutdown state. To enable the recalibration feature, CAL_EN must be set in the GLOBAL_WUT_CONFIG property, and the desired calibration period should be selected via WUT_CAL_PERIOD[2:0] in the same API property. During the calibration, the 32 kHz RC oscillator frequency is compared to the 30 MHz crystal and then adjusted accordingly. The calibration needs to start the 30 MHz crystal, which increases the average current consumption; so, a longer CAL_PERIOD results in a lower average current consumption. The 32 kHz crystal accuracy is comprised of both the crystal parameters and the internal circuit. The crystal accuracy can be defined as the initial error + aging + temperature drift + detuning from the internal oscillator circuit. The error caused by the internal circuit is typically less than 10 ppm. Refer to the API documentation for WUT related API commands and properties. 263 Rev. 1.0 Si106x/108x Table 27.1. WUT Specific Commands and Properties API Properties Description GLOBAL_WUT_CONFIG GLOBAL WUT configuration WUT_EN--Enable/disable wake up timer. WUT_LBD_EN--Enable/disable low battery detect measurement on WUT interval. WUT_LDC_EN: 0 = Disable low duty cycle operation. 1 = RX LDC operation treated as wake up START_RX WUT state is used 2 = TX LDC operation treated as wakeup START_TX WUT state is used CAL_EN--Enable calibration of the 32 kHz RC oscillator WUT_CAL_PERIOD[2:0]--Sets calibration period. GLOBAL_WUT_M_15_ 8 Sets HW WUT_M[15:8] WUT_M--Parameter to set the actual wakeup time. See equation above. GLOBAL_ WUT_M_7_0 Sets HW WUT_M[7:0] WUT_M--Parameter to set the actual wakeup time. See equation above. GLOBAL_WUT_R Sets WUT_R[4:0] Sets WUT_SLEEP to choose WUT state WUT_R--Parameter to set the actual wakeup time. See equation above. WUT_SLEEP: 0 = Go to ready state after WUT 1 = Go to sleep state after WUT GLOBAL_WUT_LDC Requirements/Notes Sets FW internal WUT_LDC--Parameter to set the actual wakeup time. See equation in "27.2. Low Duty Cycle Mode (Auto RX WakeWUT_LDC Up)" . Rev. 1.0 264 Si106x/108x 27.2. Low Duty Cycle Mode (Auto RX Wake-Up) The Low Duty Cycle (LDC) mode is implemented to automatically wake-up the receiver to check if a valid signal is available or to enable the transmitter to send a packet. It allows low average current polling operation by the Si106x for which the wake-up timer (WUT) is used. RX and TX LDC operation must be set via the GLOBAL_WUT_CONFIG property when setting up the WUT. The LDC wake-up period is determined by the following formula: WUT_R 42 LDC = WUT_LDC ---------------------------- ms 32 768 where the WUT_LDC parameter can be set by the GLOBAL_WUT_LDC property. The WUT period must be set in conjunction with the LDC mode duration; for the relevant API properties, see the wake-up timer (WUT) section. Figure 27.1. RX and TX LDC Sequences The basic operation of RX LDC mode is shown in Figure 27.2. The receiver periodically wakes itself up to work on RX_STATE during LDC mode duration. If a valid preamble is not detected, a receive error is detected, or an entire packet is not received, the receiver returns to the WUT state (i.e., ready or sleep) at the end of LDC mode duration and remains in that mode until the beginning of the next wake-up period. If a valid preamble or sync word is detected, the receiver delays the LDC mode duration to receive the entire packet. If a packet is not received during two LDC mode durations, the receiver returns to the WUT state at the last LDC mode duration until the beginning of the next wake-up period. Figure 27.2. Low Duty Cycle Mode for RX In TX LDC mode, the transmitter periodically wakes itself up to transmit a packet that is in the data buffer. If a packet has been transmitted, nIRQ goes low if the option is set in the INT_CTL_ENABLE property. After transmitting, the transmitter immediately returns to the WUT state and stays there until the next wake-up time expires. 265 Rev. 1.0 Si106x/108x 27.3. Antenna Diversity (Si1060-Si1063, Si1080-Si1083) To mitigate the problem of frequency-selective fading due to multipath propagation, some transceiver systems use a scheme known as antenna diversity. In this scheme, two antennas are used. Each time the transceiver enters RX mode the receive signal strength from each antenna is evaluated. This evaluation process takes place during the preamble portion of the packet. The antenna with the strongest received signal is then used for the remainder of that RX packet. The same antenna will also be used for the next corresponding TX packet. This chip fully supports antenna diversity with an integrated antenna diversity control algorithm. The required signals needed to control an external SPDT RF switch (such as a PIN diode or GaAs switch) are available on the GPIOx pins. The operation of these GPIO signals is programmable to allow for different antenna diversity architectures and configurations. The antdiv[2:0] bits are found in the MODEM_ANT_DIV_CONTROL API property descriptions and enable the antenna diversity mode. The GPIO pins are capable of sourcing up to 5 mA of current; so, it may be used directly to forward-bias a PIN diode if desired. The antenna diversity algorithm will automatically toggle back and forth between the antennas until the packet starts to arrive. The recommended preamble length for optimal antenna selection is 8 bytes. Rev. 1.0 266 Si106x/108x 28. SMBus The SMBus I/O interface is a two-wire, bi-directional serial bus. The SMBus is compliant with the System Management Bus Specification, version 1.1, and compatible with the I2C serial bus. Reads and writes to the interface by the system controller are byte oriented with the SMBus interface autonomously controlling the serial transfer of the data. Data can be transferred at up to 1/20th of the system clock as a master or slave (this can be faster than allowed by the SMBus specification, depending on the system clock used). A method of extending the clock-low duration is available to accommodate devices with different speed capabilities on the same bus. The SMBus interface may operate as a master and/or slave, and may function on a bus with multiple masters. The SMBus provides control of SDA (serial data), SCL (serial clock) generation and synchronization, arbitration logic, and START/STOP control and generation. The SMBus peripheral can be fully driven by software (i.e., software accepts/rejects slave addresses, and generates ACKs), or hardware slave address recognition and automatic ACK generation can be enabled to minimize software overhead. A block diagram of the SMBus peripheral and the associated SFRs is shown in Figure 28.1. SMB0CN M T S S A A A S A X T T CR C I SMAOK B K T O R L E D QO R E S T SMB0CF E I B E S S S S N N U XMMMM S H S T B B B B M Y H T F CC B OO T S S L E E 1 0 D SMBUS CONTROL LOGIC Arbitration SCL Synchronization SCL Generation (Master Mode) SDA Control Hardware Slave Address Recognition Hardware ACK Generation Data Path IRQ Generation Control Interrupt Request 00 T0 Overflow 01 T1 Overflow 10 TMR2H Overflow 11 TMR2L Overflow SCL Control S L V 5 S L V 4 S L V 3 S L V 2 S L V 1 SMB0ADR SG L C V 0 S S S S S S S L L L L L L L V V V V V V V MMMMMMM 6 5 4 3 2 1 0 SMB0ADM C R O S S B A R N SDA Control SMB0DAT 7 6 5 4 3 2 1 0 S L V 6 SCL FILTER Port I/O SDA FILTER E H A C K N Figure 28.1. SMBus Block Diagram Rev. 1.0 267 Si106x/108x 28.1. Supporting Documents It is assumed the reader is familiar with or has access to the following supporting documents: 1. The I2C-Bus and How to Use It (including specifications), Philips Semiconductor. 2. The I2C-Bus Specification--Version 2.0, Philips Semiconductor. 3. System Management Bus Specification--Version 1.1, SBS Implementers Forum. 28.2. SMBus Configuration Figure 28.2 shows a typical SMBus configuration. The SMBus specification allows any recessive voltage between 3.0 V and 5.0 V; different devices on the bus may operate at different voltage levels. The bi-directional SCL (serial clock) and SDA (serial data) lines must be connected to a positive power supply voltage through a pullup resistor or similar circuit. Every device connected to the bus must have an open-drain or open-collector output for both the SCL and SDA lines, so that both are pulled high (recessive state) when the bus is free. The maximum number of devices on the bus is limited only by the requirement that the rise and fall times on the bus not exceed 300 ns and 1000 ns, respectively. VDD = 5V VDD = 3V VDD = 5V VDD = 3V Master Device Slave Device 1 Slave Device 2 SDA SCL Figure 28.2. Typical SMBus Configuration 28.3. SMBus Operation Two types of data transfers are possible: data transfers from a master transmitter to an addressed slave receiver (WRITE), and data transfers from an addressed slave transmitter to a master receiver (READ). The master device initiates both types of data transfers and provides the serial clock pulses on SCL. The SMBus interface may operate as a master or a slave, and multiple master devices on the same bus are supported. If two or more masters attempt to initiate a data transfer simultaneously, an arbitration scheme is employed with a single master always winning the arbitration. Note that it is not necessary to specify one device as the Master in a system; any device who transmits a START and a slave address becomes the master for the duration of that transfer. A typical SMBus transaction consists of a START condition followed by an address byte (Bits7-1: 7-bit slave address; Bit0: R/W direction bit), one or more bytes of data, and a STOP condition. Bytes that are received (by a master or slave) are acknowledged (ACK) with a low SDA during a high SCL (see Figure 28.3). If the receiving device does not ACK, the transmitting device will read a NACK (not acknowledge), which is a high SDA during a high SCL. The direction bit (R/W) occupies the least-significant bit position of the address byte. The direction bit is set to logic 1 to indicate a "READ" operation and cleared to logic 0 to indicate a "WRITE" operation. 268 Rev. 1.0 Si106x/108x All transactions are initiated by a master, with one or more addressed slave devices as the target. The master generates the START condition and then transmits the slave address and direction bit. If the transaction is a WRITE operation from the master to the slave, the master transmits the data a byte at a time waiting for an ACK from the slave at the end of each byte. For READ operations, the slave transmits the data waiting for an ACK from the master at the end of each byte. At the end of the data transfer, the master generates a STOP condition to terminate the transaction and free the bus. Figure 28.3 illustrates a typical SMBus transaction. SCL SDA SLA6 START SLA5-0 Slave Address + R/W R/W D7 ACK D6-0 Data Byte NACK STOP Figure 28.3. SMBus Transaction 28.3.1. Transmitter vs. Receiver On the SMBus communications interface, a device is the "transmitter" when it is sending an address or data byte to another device on the bus. A device is a "receiver" when an address or data byte is being sent to it from another device on the bus. The transmitter controls the SDA line during the address or data byte. After each byte of address or data information is sent by the transmitter, the receiver sends an ACK or NACK bit during the ACK phase of the transfer, during which time the receiver controls the SDA line. 28.3.2. Arbitration A master may start a transfer only if the bus is free. The bus is free after a STOP condition or after the SCL and SDA lines remain high for a specified time (see Section "28.3.5. SCL High (SMBus Free) Timeout" on page 270). In the event that two or more devices attempt to begin a transfer at the same time, an arbitration scheme is employed to force one master to give up the bus. The master devices continue transmitting until one attempts a HIGH while the other transmits a LOW. Since the bus is open-drain, the bus will be pulled LOW. The master attempting the HIGH will detect a LOW SDA and lose the arbitration. The winning master continues its transmission without interruption; the losing master becomes a slave and receives the rest of the transfer if addressed. This arbitration scheme is non-destructive: one device always wins, and no data is lost. 28.3.3. Clock Low Extension SMBus provides a clock synchronization mechanism, similar to I2C, which allows devices with different speed capabilities to coexist on the bus. A clock-low extension is used during a transfer in order to allow slower slave devices to communicate with faster masters. The slave may temporarily hold the SCL line LOW to extend the clock low period, effectively decreasing the serial clock frequency. Rev. 1.0 269 Si106x/108x 28.3.4. SCL Low Timeout If the SCL line is held low by a slave device on the bus, no further communication is possible. Furthermore, the master cannot force the SCL line high to correct the error condition. To solve this problem, the SMBus protocol specifies that devices participating in a transfer must detect any clock cycle held low longer than 25 ms as a "timeout" condition. Devices that have detected the timeout condition must reset the communication no later than 10 ms after detecting the timeout condition. When the SMBTOE bit in SMB0CF is set, Timer 3 is used to detect SCL low timeouts. Timer 3 is forced to reload when SCL is high, and allowed to count when SCL is low. With Timer 3 enabled and configured to overflow after 25 ms (and SMBTOE set), the Timer 3 interrupt service routine can be used to reset (disable and re-enable) the SMBus in the event of an SCL low timeout. 28.3.5. SCL High (SMBus Free) Timeout The SMBus specification stipulates that if the SCL and SDA lines remain high for more that 50 s, the bus is designated as free. When the SMBFTE bit in SMB0CF is set, the bus will be considered free if SCL and SDA remain high for more than 10 SMBus clock source periods (as defined by the timer configured for the SMBus clock source). If the SMBus is waiting to generate a Master START, the START will be generated following this timeout. Note that a clock source is required for free timeout detection, even in a slave-only implementation. 28.4. Using the SMBus The SMBus can operate in both Master and Slave modes. The interface provides timing and shifting control for serial transfers; higher level protocol is determined by user software. The SMBus interface provides the following application-independent features: Byte-wise serial data transfers Clock signal generation on SCL (Master Mode only) and SDA data synchronization Timeout/bus error recognition, as defined by the SMB0CF configuration register START/STOP timing, detection, and generation Bus arbitration Interrupt generation Status information Optional hardware recognition of slave address and automatic acknowledgment of address/data SMBus interrupts are generated for each data byte or slave address that is transferred. When hardware acknowledgment is disabled, the point at which the interrupt is generated depends on whether the hardware is acting as a data transmitter or receiver. When a transmitter (i.e. sending address/data, receiving an ACK), this interrupt is generated after the ACK cycle so that software may read the received ACK value; when receiving data (i.e. receiving address/data, sending an ACK), this interrupt is generated before the ACK cycle so that software may define the outgoing ACK value. If hardware acknowledgment is enabled, these interrupts are always generated after the ACK cycle. See Section 28.5 for more details on transmission sequences. Interrupts are also generated to indicate the beginning of a transfer when a master (START generated), or the end of a transfer when a slave (STOP detected). Software should read the SMB0CN (SMBus Control register) to find the cause of the SMBus interrupt. The SMB0CN register is described in Section 28.4.2; Table 28.5 provides a quick SMB0CN decoding reference. 270 Rev. 1.0 Si106x/108x 28.4.1. SMBus Configuration Register The SMBus Configuration register (SMB0CF) is used to enable the SMBus Master and/or Slave modes, select the SMBus clock source, and select the SMBus timing and timeout options. When the ENSMB bit is set, the SMBus is enabled for all master and slave events. Slave events may be disabled by setting the INH bit. With slave events inhibited, the SMBus interface will still monitor the SCL and SDA pins; however, the interface will NACK all received addresses and will not generate any slave interrupts. When the INH bit is set, all slave events will be inhibited following the next START (interrupts will continue for the duration of the current transfer). Table 28.1. SMBus Clock Source Selection SMBCS1 SMBCS0 SMBus Clock Source 0 0 1 1 0 1 0 1 Timer 0 Overflow Timer 1 Overflow Timer 2 High Byte Overflow Timer 2 Low Byte Overflow The SMBCS1-0 bits select the SMBus clock source, which is used only when operating as a master or when the Free Timeout detection is enabled. When operating as a master, overflows from the selected source determine the absolute minimum SCL low and high times as defined in Equation 28.1. Note that the selected clock source may be shared by other peripherals so long as the timer is left running at all times. For example, Timer 1 overflows may generate the SMBus and UART baud rates simultaneously. Timer configuration is covered in Section "31. Timers" on page 311. 1 T HighMin = T LowMin = ---------------------------------------------f ClockSourceOverflow Equation 28.1. Minimum SCL High and Low Times The selected clock source should be configured to establish the minimum SCL High and Low times as per Equation 28.1. When the interface is operating as a master (and SCL is not driven or extended by any other devices on the bus), the typical SMBus bit rate is approximated by Equation 28.2. f ClockSourceOverflow BitRate = ---------------------------------------------3 Equation 28.2. Typical SMBus Bit Rate Figure 28.4 shows the typical SCL generation described by Equation 28.2. Notice that THIGH is typically twice as large as TLOW. The actual SCL output may vary due to other devices on the bus (SCL may be extended low by slower slave devices, or driven low by contending master devices). The bit rate when operating as a master will never exceed the limits defined by equation Equation 28.1. Timer Source Overflows SCL TLow SCL High Timeout THigh Figure 28.4. Typical SMBus SCL Generation Rev. 1.0 271 Si106x/108x Setting the EXTHOLD bit extends the minimum setup and hold times for the SDA line. The minimum SDA setup time defines the absolute minimum time that SDA is stable before SCL transitions from low-to-high. The minimum SDA hold time defines the absolute minimum time that the current SDA value remains stable after SCL transitions from high-to-low. EXTHOLD should be set so that the minimum setup and hold times meet the SMBus Specification requirements of 250 ns and 300 ns, respectively. Table 28.2 shows the minimum setup and hold times for the two EXTHOLD settings. Setup and hold time extensions are typically necessary when SYSCLK is above 10 MHz. Table 28.2. Minimum SDA Setup and Hold Times EXTHOLD 0 1 Minimum SDA Setup Time Tlow - 4 system clocks or 1 system clock + s/w delay* 11 system clocks Minimum SDA Hold Time 3 system clocks 12 system clocks Note: Setup Time for ACK bit transmissions and the MSB of all data transfers. When using software acknowledgment, the s/w delay occurs between the time SMB0DAT or ACK is written and when SI is cleared. Note that if SI is cleared in the same write that defines the outgoing ACK value, s/w delay is zero. With the SMBTOE bit set, Timer 3 should be configured to overflow after 25 ms in order to detect SCL low timeouts (see Section "28.3.4. SCL Low Timeout" on page 270). The SMBus interface will force Timer 3 to reload while SCL is high, and allow Timer 3 to count when SCL is low. The Timer 3 interrupt service routine should be used to reset SMBus communication by disabling and re-enabling the SMBus. SMBus Free Timeout detection can be enabled by setting the SMBFTE bit. When this bit is set, the bus will be considered free if SDA and SCL remain high for more than 10 SMBus clock source periods (see Figure 28.4). 272 Rev. 1.0 Si106x/108x SFR Definition 28.1. SMB0CF: SMBus Clock/Configuration Bit 7 6 5 4 Name ENSMB INH BUSY Type R/W R/W R R/W Reset 0 0 0 0 EXTHOLD SMBTOE SFR Page = 0x0; SFR Address = 0xC1 Bit Name 7 ENSMB 3 2 1 0 SMBFTE SMBCS[1:0] R/W R/W R/W 0 0 0 0 Function SMBus Enable. This bit enables the SMBus interface when set to 1. When enabled, the interface constantly monitors the SDA and SCL pins. 6 INH SMBus Slave Inhibit. When this bit is set to logic 1, the SMBus does not generate an interrupt when slave events occur. This effectively removes the SMBus slave from the bus. Master Mode interrupts are not affected. 5 BUSY SMBus Busy Indicator. This bit is set to logic 1 by hardware when a transfer is in progress. It is cleared to logic 0 when a STOP or free-timeout is sensed. 4 EXTHOLD SMBus Setup and Hold Time Extension Enable. This bit controls the SDA setup and hold times according to Table 28.2. 0: SDA Extended Setup and Hold Times disabled. 1: SDA Extended Setup and Hold Times enabled. 3 SMBTOE SMBus SCL Timeout Detection Enable. This bit enables SCL low timeout detection. If set to logic 1, the SMBus forces Timer 3 to reload while SCL is high and allows Timer 3 to count when SCL goes low. If Timer 3 is configured to Split Mode, only the High Byte of the timer is held in reload while SCL is high. Timer 3 should be programmed to generate interrupts at 25 ms, and the Timer 3 interrupt service routine should reset SMBus communication. 2 SMBFTE SMBus Free Timeout Detection Enable. When this bit is set to logic 1, the bus will be considered free if SCL and SDA remain high for more than 10 SMBus clock source periods. 1 :0 SMBCS[1:0] SMBus Clock Source Selection. These two bits select the SMBus clock source, which is used to generate the SMBus bit rate. The selected device should be configured according to Equation 28.1. 00: Timer 0 Overflow 01: Timer 1 Overflow 10:Timer 2 High Byte Overflow 11: Timer 2 Low Byte Overflow Rev. 1.0 273 Si106x/108x 28.4.2. SMB0CN Control Register SMB0CN is used to control the interface and to provide status information (see SFR Definition 28.2). The higher four bits of SMB0CN (MASTER, TXMODE, STA, and STO) form a status vector that can be used to jump to service routines. MASTER indicates whether a device is the master or slave during the current transfer. TXMODE indicates whether the device is transmitting or receiving data for the current byte. STA and STO indicate that a START and/or STOP has been detected or generated since the last SMBus interrupt. STA and STO are also used to generate START and STOP conditions when operating as a master. Writing a 1 to STA will cause the SMBus interface to enter Master Mode and generate a START when the bus becomes free (STA is not cleared by hardware after the START is generated). Writing a 1 to STO while in Master Mode will cause the interface to generate a STOP and end the current transfer after the next ACK cycle. If STO and STA are both set (while in Master Mode), a STOP followed by a START will be generated. The ARBLOST bit indicates that the interface has lost an arbitration. This may occur anytime the interface is transmitting (master or slave). A lost arbitration while operating as a slave indicates a bus error condition. ARBLOST is cleared by hardware each time SI is cleared. The SI bit (SMBus Interrupt Flag) is set at the beginning and end of each transfer, after each byte frame, or when an arbitration is lost; see Table 28.3 for more details. Important Note About the SI Bit: The SMBus interface is stalled while SI is set; thus SCL is held low, and the bus is stalled until software clears SI. 28.4.2.1. Software ACK Generation When the EHACK bit in register SMB0ADM is cleared to 0, the firmware on the device must detect incoming slave addresses and ACK or NACK the slave address and incoming data bytes. As a receiver, writing the ACK bit defines the outgoing ACK value; as a transmitter, reading the ACK bit indicates the value received during the last ACK cycle. ACKRQ is set each time a byte is received, indicating that an outgoing ACK value is needed. When ACKRQ is set, software should write the desired outgoing value to the ACK bit before clearing SI. A NACK will be generated if software does not write the ACK bit before clearing SI. SDA will reflect the defined ACK value immediately following a write to the ACK bit; however SCL will remain low until SI is cleared. If a received slave address is not acknowledged, further slave events will be ignored until the next START is detected. 28.4.2.2. Hardware ACK Generation When the EHACK bit in register SMB0ADM is set to 1, automatic slave address recognition and ACK generation is enabled. More detail about automatic slave address recognition can be found in Section 28.4.3. As a receiver, the value currently specified by the ACK bit will be automatically sent on the bus during the ACK cycle of an incoming data byte. As a transmitter, reading the ACK bit indicates the value received on the last ACK cycle. The ACKRQ bit is not used when hardware ACK generation is enabled. If a received slave address is NACKed by hardware, further slave events will be ignored until the next START is detected, and no interrupt will be generated. Table 28.3 lists all sources for hardware changes to the SMB0CN bits. Refer to Table 28.5 for SMBus status decoding using the SMB0CN register. Refer to "Limitations for Hardware Acknowledge Feature" on page 279 when using hardware ACK generation. 274 Rev. 1.0 Si106x/108x SFR Definition 28.2. SMB0CN: SMBus Control Bit 7 6 5 4 3 2 1 0 Name MASTER TXMODE STA STO ACKRQ ARBLOST ACK SI Type R R R/W R/W R R R/W R/W Reset 0 0 0 0 0 0 0 0 SFR Page = 0x0; SFR Address = 0xC0; Bit-Addressable Bit Name Description Read Write 7 MASTER SMBus Master/Slave Indicator. This read-only bit indicates when the SMBus is operating as a master. 0: SMBus operating in slave mode. 1: SMBus operating in master mode. N/A 6 TXMODE SMBus Transmit Mode Indicator. This read-only bit indicates when the SMBus is operating as a transmitter. 0: SMBus in Receiver Mode. 1: SMBus in Transmitter Mode. N/A 5 STA SMBus Start Flag. 0: No Start or repeated Start detected. 1: Start or repeated Start detected. 0: No Start generated. 1: When Configured as a Master, initiates a START or repeated START. 4 STO SMBus Stop Flag. 0: No Stop condition detected. 1: Stop condition detected (if in Slave Mode) or pending (if in Master Mode). 0: No STOP condition is transmitted. 1: When configured as a Master, causes a STOP condition to be transmitted after the next ACK cycle. Cleared by Hardware. 3 ACKRQ SMBus Acknowledge Request. 0: No Ack requested 1: ACK requested N/A 0: No arbitration error. 1: Arbitration Lost N/A 2 ARBLOST SMBus Arbitration Lost Indicator. 1 ACK SMBus Acknowledge. 0: NACK received. 1: ACK received. 0: Send NACK 1: Send ACK 0 SI SMBus Interrupt Flag. 0: No interrupt pending 0: Clear interrupt, and initiate next state machine event. 1: Force interrupt. This bit is set by hardware 1: Interrupt Pending under the conditions listed in Table 15.3. SI must be cleared by software. While SI is set, SCL is held low and the SMBus is stalled. Rev. 1.0 275 Si106x/108x Table 28.3. Sources for Hardware Changes to SMB0CN Bit Set by Hardware When: MASTER A START is generated. Cleared by Hardware When: TXMODE START is generated. SMB0DAT is written before the start of an SMBus frame. A START followed by an address byte is received. A STOP is detected while addressed as a slave. Arbitration is lost due to a detected STOP. A byte has been received and an ACK response value is needed (only when hardware ACK is not enabled). A repeated START is detected as a MASTER when STA is low (unwanted repeated START). SCL is sensed low while attempting to generate a STOP or repeated START condition. SDA is sensed low while transmitting a 1 (excluding ACK bits). The incoming ACK value is low (ACKNOWLEDGE). A START has been generated. Lost arbitration. A byte has been transmitted and an ACK/NACK received. A byte has been received. A START or repeated START followed by a slave address + R/W has been received. A STOP has been received. A STOP is generated. Arbitration is lost. A START is detected. Arbitration is lost. SMB0DAT is not written before the start of an SMBus frame. Must be cleared by software. A pending STOP is generated. After each ACK cycle. Each time SI is cleared. The incoming ACK value is high (NOT ACKNOWLEDGE). Must be cleared by software. STA STO ACKRQ ARBLOST ACK SI 276 Rev. 1.0 Si106x/108x 28.4.3. Hardware Slave Address Recognition The SMBus hardware has the capability to automatically recognize incoming slave addresses and send an ACK without software intervention. Automatic slave address recognition is enabled by setting the EHACK bit in register SMB0ADM to 1. This will enable both automatic slave address recognition and automatic hardware ACK generation for received bytes (as a master or slave). More detail on automatic hardware ACK generation can be found in Section 28.4.2.2. The registers used to define which address(es) are recognized by the hardware are the SMBus Slave Address register (SFR Definition 28.3) and the SMBus Slave Address Mask register (SFR Definition 28.4). A single address or range of addresses (including the General Call Address 0x00) can be specified using these two registers. The most-significant seven bits of the two registers are used to define which addresses will be ACKed. A 1 in bit positions of the slave address mask SLVM[6:0] enable a comparison between the received slave address and the hardware's slave address SLV[6:0] for those bits. A 0 in a bit of the slave address mask means that bit will be treated as a "don't care" for comparison purposes. In this case, either a 1 or a 0 value are acceptable on the incoming slave address. Additionally, if the GC bit in register SMB0ADR is set to 1, hardware will recognize the General Call Address (0x00). Table 28.4 shows some example parameter settings and the slave addresses that will be recognized by hardware under those conditions. Refer to "Limitations for Hardware Acknowledge Feature" on page 279 when using hardware slave address recognition. Table 28.4. Hardware Address Recognition Examples (EHACK = 1) Hardware Slave Address SLV[6:0] Slave Address Mask SLVM[6:0] GC bit Slave Addresses Recognized by Hardware 0x34 0x34 0x34 0x34 0x70 0x7F 0x7F 0x7E 0x7E 0x73 0 1 0 1 0 0x34 0x34, 0x00 (General Call) 0x34, 0x35 0x34, 0x35, 0x00 (General Call) 0x70, 0x74, 0x78, 0x7C Rev. 1.0 277 Si106x/108x SFR Definition 28.3. SMB0ADR: SMBus Slave Address Bit 7 6 5 4 3 2 1 0 Name SLV[6:0] GC Type R/W R/W Reset 0 0 0 0 SFR Page = 0x0; SFR Address = 0xF4 Bit Name 7 :1 SLV[6:0] 0 0 0 0 Function SMBus Hardware Slave Address. Defines the SMBus Slave Address(es) for automatic hardware acknowledgement. Only address bits which have a 1 in the corresponding bit position in SLVM[6:0] are checked against the incoming address. This allows multiple addresses to be recognized. 0 GC General Call Address Enable. When hardware address recognition is enabled (EHACK = 1), this bit will determine whether the General Call Address (0x00) is also recognized by hardware. 0: General Call Address is ignored. 1: General Call Address is recognized. SFR Definition 28.4. SMB0ADM: SMBus Slave Address Mask Bit 7 6 5 4 3 2 1 0 Name SLVM[6:0] EHACK Type R/W R/W Reset 1 1 1 1 SFR Page = 0x0; SFR Address = 0xF5 Bit Name 7 :1 SLVM[6:0] 1 1 1 0 Function SMBus Slave Address Mask. Defines which bits of register SMB0ADR are compared with an incoming address byte, and which bits are ignored. Any bit set to 1 in SLVM[6:0] enables comparisons with the corresponding bit in SLV[6:0]. Bits set to 0 are ignored (can be either 0 or 1 in the incoming address). 0 EHACK Hardware Acknowledge Enable. Enables hardware acknowledgement of slave address and received data bytes. 0: Firmware must manually acknowledge all incoming address and data bytes. 1: Automatic Slave Address Recognition and Hardware Acknowledge is Enabled. 278 Rev. 1.0 Si106x/108x 28.4.4. Limitations for Hardware Acknowledge Feature In some system management bus (SMBus) configurations, the Hardware Acknowledge mechanism of the SMBus peripheral can cause incorrect or undesired behavior. The Hardware Acknowledge mechanism is enabled when the EHACK bit (SMB0ADM.0) is set to logic 1. The configurations to which these limitations do not apply are as follows: a. All SMBus configurations when Hardware Acknowledge is disabled. b. All single-master/single-slave SMBus configurations when Hardware Acknowledge is enabled and the MCU is operating as a master or slave. c. All multi-master/single-slave SMBus configurations when Hardware Acknowledge is enabled and the MCU is operating as a slave. d. All single-master/multi-slave SMBus configurations when Hardware Acknowledge is enabled and the MCU is operating as a master. These limitations only apply to the following configurations: a. All multi-slave SMBus configurations when Hardware Acknowledge is enabled and the MCU is operating as a slave. b. All multi-master SMBus configurations when Hardware Acknowledge is enabled and the MCU is operating as a master. The following issues are present when operating as a slave in a multi-slave SMBus configuration: a. When Hardware Acknowledge is enabled and SDA setup and hold times are not extended (EXTHOLD = 0 in the SMB0CF register), the SMBus hardware will always generate an SMBus interrupt following the ACK/NACK cycle of any slave address transmission on the bus, whether or not the address matches the conditions of SMB0ADR and SMB0MASK. The expected behavior is that an interrupt is only generated when the address matches. b. When Hardware Acknowledge is enabled and SDA setup and hold times are extended (EXTHOLD = 1 in the SMB0CF register), the SMBus hardware will only generate an SMBus interrupt as expected when the slave address transmission on the bus matches the conditions of SMB0ADR and SMB0MASK. However, in this mode, the Start bit (STA) will be incorrectly cleared on reception of a slave address before software vectors to the interrupt service routine. c. When Hardware Acknowledge is enabled and the ACK bit (SMB0CN.1) is set to 1, an unaddressed slave may cause interference on the SMBus by driving SDA low during an ACK cycle. The ACK bit of the unaddressed slave may be set to 1 if any device on the bus generates an ACK. Impact: a. Once the CPU enters the interrupt service routine, SCL will be asserted low until SI is cleared, causing the clock to be stretched when the MCU is not being addressed. This may limit the maximum speed of the SMBus if the master supports SCL clock stretching. Incompliant SMBus masters that do not support SCL clock stretching will not recognize that the clock is being stretched. If the CPU issues a write to SMB0DAT, it will have no effect on the bus. No data collisions will occur. b. Once the hardware has matched an address and entered the interrupt service routine, the firmware will not be able to use the Start bit to distinguish between the reception of an address byte versus the reception of a data byte. However, the hardware will still correctly acknowledge the address byte (SLA+R/W). c. The SMBus master and the addressed slave are prevented from generating a NACK by the unaddressed slave because it is holding SDA low during the ACK cycle. There is a potential for the SMBus to lock up. Rev. 1.0 279 Si106x/108x Workarounds: a. The SMBus interrupt service routine should verify an address when it is received and clear SI as soon as possible if the address does not match to minimize clock stretching. To prevent clock stretching when not being addressed, enable setup and hold time extensions (EXTHOLD = 1). b. Detection of Initial Start: To distinguish between the reception of an address byte at the beginning of a transfer versus the reception of a data byte when setup and hold time extensions are enabled (EXTHOLD = 1), software should maintain a status bit to determine whether it is currently inside or outside a transfer. Once hardware detects a matching slave address and interrupts the MCU, software should assume a start condition and set the software bit to indicate that it is currently inside a transfer. A transfer ends any time the STO bit is set or on an error condition (e.g., SCL Low Timeout). Detection of Repeated Start: To detect the reception of an address byte in the middle of a transfer when setup and hold time extensions are enabled (EXTHOLD = 1), disable setup and hold time extensions (EXTHOLD = 0) upon entry into a transfer and re-enable setup and hold time extensions (EXHOLD = 1) at the end of a transfer. c. Schedule a timer interrupt to clear the ACK bit at an interval shorter than 7 bit periods when the slave is not being addressed. For example, on a 400 kHz SMBus, the ACK bit should be cleared every 17.5 s (or at 1/7 the bus frequency, 57 kHz). As soon as a matching slave address is detected (a transfer is started), the timer which clears the ACK bit should be stopped and its interrupt flag cleared. The timer should be re-started once a stop or error condition is detected (the transfer has ended). A code example demonstrating these workarounds can be found in the SMBus examples folder with the following default location: Si106x C:\SiLabs\MCU\Examples\C8051F93x_92x\SMBus\F93x_SMBus_Slave_Multibyte_HWACK.c Si108x C:\SiLabs\MCU\Examples\C8051F91x_90x\SMBus\F91x_SMBus_Slave_Multibyte_HWACK.c The SMBus examples folder, along with examples for many additional peripherals, is created when the Silicon Laboratories IDE is installed. The latest version of the IDE may be downloaded from the software downloads page www.silabs.com/MCUDownloads on the Silicon Laboratories website. The following issue is present when operating as a master in a multi-master SMBus configuration: If the SMBus master loses arbitration in a multi-master system, it may cause interference on the SMBus by driving SDA low during the ACK cycle of transfers which it is not participating. This will occur regardless of the state of the ACK bit (SMB0CN.1). Impact: The SMBus master and slave participating in the transfer are prevented from generating a NACK by the MCU because it is holding SDA low during the ACK cycle. There is a potential for the SMBus to lock up. Workaround: Disable Hardware Acknowledge (EHACK = 0) when the MCU is operating as a master in a multi-master SMBus configuration. 280 Rev. 1.0 Si106x/108x 28.4.5. Data Register The SMBus Data register SMB0DAT holds a byte of serial data to be transmitted or one that has just been received. Software may safely read or write to the data register when the SI flag is set. Software should not attempt to access the SMB0DAT register when the SMBus is enabled and the SI flag is cleared to logic 0, as the interface may be in the process of shifting a byte of data into or out of the register. Data in SMB0DAT is always shifted out MSB first. After a byte has been received, the first bit of received data is located at the MSB of SMB0DAT. While data is being shifted out, data on the bus is simultaneously being shifted in. SMB0DAT always contains the last data byte present on the bus. In the event of lost arbitration, the transition from master transmitter to slave receiver is made with the correct data or address in SMB0DAT. SFR Definition 28.5. SMB0DAT: SMBus Data Bit 7 6 5 4 3 Name SMB0DAT[7:0] Type R/W Reset 0 0 0 0 SFR Page = 0x0; SFR Address = 0xC2 Bit Name 0 2 1 0 0 0 0 Function 7:0 SMB0DAT[7:0] SMBus Data. The SMB0DAT register contains a byte of data to be transmitted on the SMBus serial interface or a byte that has just been received on the SMBus serial interface. The CPU can read from or write to this register whenever the SI serial interrupt flag (SMB0CN.0) is set to logic 1. The serial data in the register remains stable as long as the SI flag is set. When the SI flag is not set, the system may be in the process of shifting data in/out and the CPU should not attempt to access this register. Rev. 1.0 281 Si106x/108x 28.5. SMBus Transfer Modes The SMBus interface may be configured to operate as master and/or slave. At any particular time, it will be operating in one of the following four modes: Master Transmitter, Master Receiver, Slave Transmitter, or Slave Receiver. The SMBus interface enters Master Mode any time a START is generated, and remains in Master Mode until it loses an arbitration or generates a STOP. An SMBus interrupt is generated at the end of all SMBus byte frames. Note that the position of the ACK interrupt when operating as a receiver depends on whether hardware ACK generation is enabled. As a receiver, the interrupt for an ACK occurs before the ACK with hardware ACK generation disabled, and after the ACK when hardware ACK generation is enabled. As a transmitter, interrupts occur after the ACK, regardless of whether hardware ACK generation is enabled or not. 28.5.1. Write Sequence (Master) During a write sequence, an SMBus master writes data to a slave device. The master in this transfer will be a transmitter during the address byte, and a transmitter during all data bytes. The SMBus interface generates the START condition and transmits the first byte containing the address of the target slave and the data direction bit. In this case the data direction bit (R/W) will be logic 0 (WRITE). The master then transmits one or more bytes of serial data. After each byte is transmitted, an acknowledge bit is generated by the slave. The transfer is ended when the STO bit is set and a STOP is generated. Note that the interface will switch to Master Receiver Mode if SMB0DAT is not written following a Master Transmitter interrupt. Figure 28.5 shows a typical master write sequence. Two transmit data bytes are shown, though any number of bytes may be transmitted. Notice that all of the `data byte transferred' interrupts occur after the ACK cycle in this mode, regardless of whether hardware ACK generation is enabled. Interrupts with Hardware ACK Enabled (EHACK = 1) S SLA W A Data Byte A Data Byte A P Interrupts with Hardware ACK Disabled (EHACK = 0) S = START P = STOP A = ACK W = WRITE SLA = Slave Address Received by SMBus Interface Transmitted by SMBus Interface Figure 28.5. Typical Master Write Sequence 28.5.2. Read Sequence (Master) During a read sequence, an SMBus master reads data from a slave device. The master in this transfer will be a transmitter during the address byte, and a receiver during all data bytes. The SMBus interface generates the START condition and transmits the first byte containing the address of the target slave and the data direction bit. In this case the data direction bit (R/W) will be logic 1 (READ). Serial data is then received from the slave on SDA while the SMBus outputs the serial clock. The slave transmits one or more bytes of serial data. If hardware ACK generation is disabled, the ACKRQ is set to 1 and an interrupt is generated after each received byte. Software must write the ACK bit at that time to ACK or NACK the received byte. 282 Rev. 1.0 Si106x/108x With hardware ACK generation enabled, the SMBus hardware will automatically generate the ACK/NACK, and then post the interrupt. It is important to note that the appropriate ACK or NACK value should be set up by the software prior to receiving the byte when hardware ACK generation is enabled. Writing a 1 to the ACK bit generates an ACK; writing a 0 generates a NACK. Software should write a 0 to the ACK bit for the last data transfer, to transmit a NACK. The interface exits Master Receiver Mode after the STO bit is set and a STOP is generated. The interface will switch to Master Transmitter Mode if SMB0DAT is written while an active Master Receiver. Figure 28.6 shows a typical master read sequence. Two received data bytes are shown, though any number of bytes may be received. Notice that the `data byte transferred' interrupts occur at different places in the sequence, depending on whether hardware ACK generation is enabled. The interrupt occurs before the ACK with hardware ACK generation disabled, and after the ACK when hardware ACK generation is enabled. Interrupts with Hardware ACK Enabled (EHACK = 1) S SLA R A Data Byte A Data Byte N P Interrupts with Hardware ACK Disabled (EHACK = 0) S = START P = STOP A = ACK N = NACK R = READ SLA = Slave Address Received by SMBus Interface Transmitted by SMBus Interface Figure 28.6. Typical Master Read Sequence 28.5.3. Write Sequence (Slave) During a write sequence, an SMBus master writes data to a slave device. The slave in this transfer will be a receiver during the address byte, and a receiver during all data bytes. When slave events are enabled (INH = 0), the interface enters Slave Receiver Mode when a START followed by a slave address and direction bit (WRITE in this case) is received. If hardware ACK generation is disabled, upon entering Slave Receiver Mode, an interrupt is generated and the ACKRQ bit is set. The software must respond to the received slave address with an ACK, or ignore the received slave address with a NACK. If hardware ACK generation is enabled, the hardware will apply the ACK for a slave address which matches the criteria set up by SMB0ADR and SMB0ADM. The interrupt will occur after the ACK cycle. If the received slave address is ignored (by software or hardware), slave interrupts will be inhibited until the next START is detected. If the received slave address is acknowledged, zero or more data bytes are received. If hardware ACK generation is disabled, the ACKRQ is set to 1 and an interrupt is generated after each received byte. Software must write the ACK bit at that time to ACK or NACK the received byte. With hardware ACK generation enabled, the SMBus hardware will automatically generate the ACK/NACK, and then post the interrupt. It is important to note that the appropriate ACK or NACK value should be set up by the software prior to receiving the byte when hardware ACK generation is enabled. The interface exits Slave Receiver Mode after receiving a STOP. Note that the interface will switch to Slave Transmitter Mode if SMB0DAT is written while an active Slave Receiver. Figure 28.7 shows a typical slave write sequence. Two received data bytes are shown, though any number of bytes may be received. Notice Rev. 1.0 283 Si106x/108x that the "data byte transferred" interrupts occur at different places in the sequence, depending on whether hardware ACK generation is enabled. The interrupt occurs before the ACK with hardware ACK generation disabled, and after the ACK when hardware ACK generation is enabled. Interrupts with Hardware ACK Enabled (EHACK = 1) S SLA W A Data Byte A Data Byte A P Interrupts with Hardware ACK Disabled (EHACK = 0) S = START P = STOP A = ACK W = WRITE SLA = Slave Address Received by SMBus Interface Transmitted by SMBus Interface Figure 28.7. Typical Slave Write Sequence 28.5.4. Read Sequence (Slave) During a read sequence, an SMBus master reads data from a slave device. The slave in this transfer will be a receiver during the address byte, and a transmitter during all data bytes. When slave events are enabled (INH = 0), the interface enters Slave Receiver Mode (to receive the slave address) when a START followed by a slave address and direction bit (READ in this case) is received. If hardware ACK generation is disabled, upon entering Slave Receiver Mode, an interrupt is generated and the ACKRQ bit is set. The software must respond to the received slave address with an ACK, or ignore the received slave address with a NACK. If hardware ACK generation is enabled, the hardware will apply the ACK for a slave address which matches the criteria set up by SMB0ADR and SMB0ADM. The interrupt will occur after the ACK cycle. If the received slave address is ignored (by software or hardware), slave interrupts will be inhibited until the next START is detected. If the received slave address is acknowledged, zero or more data bytes are transmitted. If the received slave address is acknowledged, data should be written to SMB0DAT to be transmitted. The interface enters Slave Transmitter Mode, and transmits one or more bytes of data. After each byte is transmitted, the master sends an acknowledge bit; if the acknowledge bit is an ACK, SMB0DAT should be written with the next data byte. If the acknowledge bit is a NACK, SMB0DAT should not be written to before SI is cleared (Note: an error condition may be generated if SMB0DAT is written following a received NACK while in Slave Transmitter Mode). The interface exits Slave Transmitter Mode after receiving a STOP. Note that the interface will switch to Slave Receiver Mode if SMB0DAT is not written following a Slave Transmitter interrupt. Figure 28.8 shows a typical slave read sequence. Two transmitted data bytes are shown, though any number of bytes may be transmitted. Notice that all of the `data byte transferred' interrupts occur after the ACK cycle in this mode, regardless of whether hardware ACK generation is enabled. 284 Rev. 1.0 Si106x/108x Interrupts with Hardware ACK Enabled (EHACK = 1) S SLA R A Data Byte A Data Byte N P Interrupts with Hardware ACK Disabled (EHACK = 0) S = START P = STOP N = NACK R = READ SLA = Slave Address Received by SMBus Interface Transmitted by SMBus Interface Figure 28.8. Typical Slave Read Sequence 28.6. SMBus Status Decoding The current SMBus status can be easily decoded using the SMB0CN register. The appropriate actions to take in response to an SMBus event depend on whether hardware slave address recognition and ACK generation is enabled or disabled. Table 28.5 describes the typical actions when hardware slave address recognition and ACK generation is disabled. Table 28.6 describes the typical actions when hardware slave address recognition and ACK generation is enabled. In the tables, STATUS VECTOR refers to the four upper bits of SMB0CN: MASTER, TXMODE, STA, and STO. The shown response options are only the typical responses; application-specific procedures are allowed as long as they conform to the SMBus specification. Highlighted responses are allowed by hardware but do not conform to the SMBus specification. Rev. 1.0 285 Si106x/108x STO ACK Load slave address + R/W into SMB0DAT. 0 0 X 1100 1 0 X 1110 0 1 X - A master data or address byte Load next data byte into SMB0- 0 DAT. was transmitted; ACK received. End transfer with STOP. 0 0 X 1100 1 X - End transfer with STOP and start 1 another transfer. 1 X - Send repeated START. 1 0 X 1110 Switch to Master Receiver Mode 0 (clear SI without writing new data to SMB0DAT). 0 X 1000 Acknowledge received byte; Read SMB0DAT. 0 0 1 1000 Send NACK to indicate last byte, 0 and send STOP. 1 0 - Send NACK to indicate last byte, 1 and send STOP followed by START. 1 0 1110 Send ACK followed by repeated 1 START. 0 1 1110 Send NACK to indicate last byte, 1 and send repeated START. 0 0 1110 Send ACK and switch to Master 0 Transmitter Mode (write to SMB0DAT before clearing SI). 0 1 1100 Send NACK and switch to Mas- 0 ter Transmitter Mode (write to SMB0DAT before clearing SI). 0 0 1100 0 0 X A master START was generated. 1100 0 0 0 0 1 A master data or address byte Set STA to restart transfer. was transmitted; NACK Abort transfer. received. Master Transmitter 0 ACK 1110 Master Receiver 1000 1 286 0 X A master data byte was received; ACK requested. Rev. 1.0 Next Status Vector Expected Values to Write ARBLOST Typical Response Options ACKRQ Current SMbus State Status Vector Mode Values Read STA Table 28.5. SMBus Status Decoding With Hardware ACK Generation Disabled (EHACK = 0) Si106x/108x STO ACK 0 A slave byte was transmitted; No action required (expecting NACK received. STOP condition). 0 0 X 0001 0 0 1 A slave byte was transmitted; Load SMB0DAT with next data ACK received. byte to transmit. 0 0 X 0100 0 1 X A Slave byte was transmitted; No action required (expecting error detected. Master to end transfer). 0 0 X 0001 ACKRQ 0 Status Vector STA Values to Write ACK Typical Response Options 0100 0 0101 0 X X An illegal STOP or bus error Clear STO. was detected while a Slave Transmission was in progress. 0 0 X - 0010 1 0 0 0 1 0000 If Read, Load SMB0DAT with 0 data byte; ACK received address 0 1 0100 NACK received address. 0 0 0 - X Lost arbitration as master; If Write, Acknowledge received 0 slave address + R/W received; address ACK requested. If Read, Load SMB0DAT with 0 data byte; ACK received address 0 1 0000 0 1 0100 1 Bus Error Condition Slave Receiver Current SMbus State ARBLOST Slave Transmitter Mode Values Read Next Status Vector Expected Table 28.5. SMBus Status Decoding With Hardware ACK Generation Disabled (EHACK = 0) (Continued) 1 X A slave address + R/W was received; ACK requested. If Write, Acknowledge received address NACK received address. 0 0 0 - Reschedule failed transfer; NACK received address. 1 0 0 1110 Clear STO. 0 0 X - 0001 0 0 X A STOP was detected while addressed as a Slave Transmitter or Slave Receiver. 1 1 X Lost arbitration while attempt- No action required (transfer ing a STOP. complete/aborted). 0 0 0 - 0000 1 0 X A slave byte was received; ACK requested. Acknowledge received byte; Read SMB0DAT. 0 0 1 0000 NACK received byte. 0 0 0 - X Lost arbitration while attempt- Abort failed transfer. ing a repeated START. Reschedule failed transfer. 0 0 X - 1 0 X 1110 X Lost arbitration due to a detected STOP. Abort failed transfer. 0 0 X - Reschedule failed transfer. 1 0 X 1110 X Lost arbitration while transmit- Abort failed transfer. ting a data byte as master. Reschedule failed transfer. 0 0 0 - 1 0 0 1110 0010 0 0001 0 0000 1 1 1 1 Rev. 1.0 287 Si106x/108x STO ACK Load slave address + R/W into SMB0DAT. 0 0 X 1100 1 0 X 1110 0 1 X - A master data or address byte Load next data byte into SMB0- 0 DAT. was transmitted; ACK received. End transfer with STOP. 0 0 X 1100 1 X - End transfer with STOP and start 1 another transfer. 1 X - Send repeated START. 1 0 X 1110 Switch to Master Receiver Mode 0 (clear SI without writing new data to SMB0DAT). Set ACK for initial data byte. 0 1 1000 Set ACK for next data byte; Read SMB0DAT. 0 0 1 1000 Set NACK to indicate next data byte as the last data byte; Read SMB0DAT. 0 0 0 1000 Initiate repeated START. 1 0 0 1110 Switch to Master Transmitter 0 Mode (write to SMB0DAT before clearing SI). 0 X 1100 Read SMB0DAT; send STOP. 0 1 0 - Read SMB0DAT; Send STOP followed by START. 1 1 0 1110 Initiate repeated START. 1 0 0 1110 Switch to Master Transmitter 0 Mode (write to SMB0DAT before clearing SI). 0 X 1100 0 0 X A master START was generated. 1100 0 0 0 0 1 A master data or address byte Set STA to restart transfer. was transmitted; NACK Abort transfer. received. Master Transmitter 0 ACK 1110 1000 0 Master Receiver 0 288 0 0 1 0 A master data byte was received; ACK sent. A master data byte was received; NACK sent (last byte). Rev. 1.0 Next Status Vector Expected Values to Write ARBLOST Typical Response Options ACKRQ Current SMbus State Status Vector Mode Values Read STA Table 28.6. SMBus Status Decoding With Hardware ACK Generation Enabled (EHACK = 1) Si106x/108x STO ACK 0 A slave byte was transmitted; No action required (expecting NACK received. STOP condition). 0 0 X 0001 0 0 1 A slave byte was transmitted; Load SMB0DAT with next data ACK received. byte to transmit. 0 0 X 0100 0 1 X A Slave byte was transmitted; No action required (expecting error detected. Master to end transfer). 0 0 X 0001 ACKRQ 0 Status Vector STA Values to Write ACK Typical Response Options 0100 0 0101 0 X X An illegal STOP or bus error Clear STO. was detected while a Slave Transmission was in progress. 0 0 X - 0010 0 0 If Write, Set ACK for first data byte. 0 0 1 If Read, Load SMB0DAT with data byte 0 0 X 0100 X Lost arbitration as master; If Write, Set ACK for first data slave address + R/W received; byte. ACK sent. If Read, Load SMB0DAT with data byte 0 0 1 0 0 X 0100 Reschedule failed transfer 1 0 X 1110 Clear STO. 0 0 X - 0 Bus Error Condition Slave Receiver Current SMbus State ARBLOST Slave Transmitter Mode Values Read Next Status Vector Expected Table 28.6. SMBus Status Decoding With Hardware ACK Generation Enabled (EHACK = 1) (Continued) 1 X A slave address + R/W was received; ACK sent. 0000 0000 0001 0 0 X A STOP was detected while addressed as a Slave Transmitter or Slave Receiver. 0 1 X Lost arbitration while attempt- No action required (transfer ing a STOP. complete/aborted). 0 0 0 - 0000 0 0 X A slave byte was received. Set ACK for next data byte; Read SMB0DAT. 0 0 1 0000 Set NACK for next data byte; Read SMB0DAT. 0 0 0 0000 X Lost arbitration while attempt- Abort failed transfer. ing a repeated START. Reschedule failed transfer. 0 0 X - 1 0 X 1110 X Lost arbitration due to a detected STOP. Abort failed transfer. 0 0 X - Reschedule failed transfer. 1 0 X 1110 X Lost arbitration while transmit- Abort failed transfer. ting a data byte as master. Reschedule failed transfer. 0 0 X - 1 0 X 1110 0010 0 0001 0 0000 0 1 1 1 Rev. 1.0 289 Si106x/108x 29. UART0 UART0 is an asynchronous, full duplex serial port offering modes 1 and 3 of the standard 8051 UART. Enhanced baud rate support allows a wide range of clock sources to generate standard baud rates (details in Section "29.1. Enhanced Baud Rate Generation" on page 291). Received data buffering allows UART0 to start reception of a second incoming data byte before software has finished reading the previous data byte. UART0 has two associated SFRs: Serial Control Register 0 (SCON0) and Serial Data Buffer 0 (SBUF0). The single SBUF0 location provides access to both transmit and receive registers. Writes to SBUF0 always access the Transmit register. Reads of SBUF0 always access the buffered Receive register; it is not possible to read data from the Transmit register. With UART0 interrupts enabled, an interrupt is generated each time a transmit is completed (TI0 is set in SCON0), or a data byte has been received (RI0 is set in SCON0). The UART0 interrupt flags are not cleared by hardware when the CPU vectors to the interrupt service routine. They must be cleared manually by software, allowing software to determine the cause of the UART0 interrupt (transmit complete or receive complete). SFR Bus Write to SBUF TB8 SBUF (TX Shift) SET D Q TX CLR Crossbar Zero Detector Stop Bit Shift Start Data Tx Control Tx Clock Send Tx IRQ TI MCE REN TB8 RB8 TI RI SMODE SCON UART Baud Rate Generator RI Serial Port Interrupt Port I/O Rx IRQ Rx Clock Rx Control Start Shift 0x1FF RB8 Load SBUF Input Shift Register (9 bits) Load SBUF SBUF (RX Latch) Read SBUF SFR Bus RX Crossbar Figure 29.1. UART0 Block Diagram Rev. 1.0 290 Si106x/108x 29.1. Enhanced Baud Rate Generation The UART0 baud rate is generated by Timer 1 in 8-bit auto-reload mode. The TX clock is generated by TL1; the RX clock is generated by a copy of TL1 (shown as RX Timer in Figure 29.2), which is not useraccessible. Both TX and RX Timer overflows are divided by two to generate the TX and RX baud rates. The RX Timer runs when Timer 1 is enabled, and uses the same reload value (TH1). However, an RX Timer reload is forced when a START condition is detected on the RX pin. This allows a receive to begin any time a START is detected, independent of the TX Timer state. Timer 1 TL1 UART Overflow 2 TX Clock Overflow 2 RX Clock TH1 Start Detected RX Timer Figure 29.2. UART0 Baud Rate Logic Timer 1 should be configured for Mode 2, 8-bit auto-reload (see Section "31.1.3. Mode 2: 8-bit Counter/Timer with Auto-Reload" on page 314). The Timer 1 reload value should be set so that overflows will occur at two times the desired UART baud rate frequency. Note that Timer 1 may be clocked by one of six sources: SYSCLK, SYSCLK / 4, SYSCLK / 12, SYSCLK / 48, the external oscillator clock / 8, or an external input T1. For any given Timer 1 clock source, the UART0 baud rate is determined by Equation 29.1-A and Equation 29.1-B. A) 1 UartBaudRate = --- T1_Overflow_Rate 2 B) T1 CLK T1_Overflow_Rate = -------------------------256 - TH1 Equation 29.1. UART0 Baud Rate Where T1CLK is the frequency of the clock supplied to Timer 1, and T1H is the high byte of Timer 1 (reload value). Timer 1 clock frequency is selected as described in Section "31.1. Timer 0 and Timer 1" on page 313. A quick reference for typical baud rates and system clock frequencies is given in Table 29.1 through Table 29.2. Note that the internal oscillator may still generate the system clock when the external oscillator is driving Timer 1. 291 Rev. 1.0 Si106x/108x 29.2. Operational Modes UART0 provides standard asynchronous, full duplex communication. The UART mode (8-bit or 9-bit) is selected by the S0MODE bit (SCON0.7). Typical UART connection options are shown below. Figure 29.3. UART Interconnect Diagram 29.2.1. 8-Bit UART 8-Bit UART mode uses a total of 10 bits per data byte: one start bit, eight data bits (LSB first), and one stop bit. Data are transmitted LSB first from the TX0 pin and received at the RX0 pin. On receive, the eight data bits are stored in SBUF0 and the stop bit goes into RB80 (SCON0.2). Data transmission begins when software writes a data byte to the SBUF0 register. The TI0 Transmit Interrupt Flag (SCON0.1) is set at the end of the transmission (the beginning of the stop-bit time). Data reception can begin any time after the REN0 Receive Enable bit (SCON0.4) is set to logic 1. After the stop bit is received, the data byte will be loaded into the SBUF0 receive register if the following conditions are met: RI0 must be logic 0, and if MCE0 is logic 1, the stop bit must be logic 1. In the event of a receive data overrun, the first received 8 bits are latched into the SBUF0 receive register and the following overrun data bits are lost. If these conditions are met, the eight bits of data is stored in SBUF0, the stop bit is stored in RB80 and the RI0 flag is set. If these conditions are not met, SBUF0 and RB80 will not be loaded and the RI0 flag will not be set. An interrupt will occur if enabled when either TI0 or RI0 is set. MARK SPACE START BIT D0 D1 D2 D3 D4 D5 D6 D7 STOP BIT BIT TIMES BIT SAMPLING Figure 29.4. 8-Bit UART Timing Diagram Rev. 1.0 292 Si106x/108x 29.2.2. 9-Bit UART 9-bit UART mode uses a total of eleven bits per data byte: a start bit, 8 data bits (LSB first), a programmable ninth data bit, and a stop bit. The state of the ninth transmit data bit is determined by the value in TB80 (SCON0.3), which is assigned by user software. It can be assigned the value of the parity flag (bit P in register PSW) for error detection, or used in multiprocessor communications. On receive, the ninth data bit goes into RB80 (SCON0.2) and the stop bit is ignored. Data transmission begins when an instruction writes a data byte to the SBUF0 register. The TI0 Transmit Interrupt Flag (SCON0.1) is set at the end of the transmission (the beginning of the stop-bit time). Data reception can begin any time after the REN0 Receive Enable bit (SCON0.4) is set to 1. After the stop bit is received, the data byte will be loaded into the SBUF0 receive register if the following conditions are met: (1) RI0 must be logic 0, and (2) if MCE0 is logic 1, the 9th bit must be logic 1 (when MCE0 is logic 0, the state of the ninth data bit is unimportant). If these conditions are met, the eight bits of data are stored in SBUF0, the ninth bit is stored in RB80, and the RI0 flag is set to 1. If the above conditions are not met, SBUF0 and RB80 will not be loaded and the RI0 flag will not be set to 1. A UART0 interrupt will occur if enabled when either TI0 or RI0 is set to 1. MARK SPACE START BIT D0 D1 D2 D3 D4 D5 D6 D7 D8 STOP BIT BIT TIMES BIT SAMPLING Figure 29.5. 9-Bit UART Timing Diagram 29.3. Multiprocessor Communications 9-Bit UART mode supports multiprocessor communication between a master processor and one or more slave processors by special use of the ninth data bit. When a master processor wants to transmit to one or more slaves, it first sends an address byte to select the target(s). An address byte differs from a data byte in that its ninth bit is logic 1; in a data byte, the ninth bit is always set to logic 0. Setting the MCE0 bit (SCON0.5) of a slave processor configures its UART such that when a stop bit is received, the UART will generate an interrupt only if the ninth bit is logic 1 (RB80 = 1) signifying an address byte has been received. In the UART interrupt handler, software will compare the received address with the slave's own assigned 8-bit address. If the addresses match, the slave will clear its MCE0 bit to enable interrupts on the reception of the following data byte(s). Slaves that weren't addressed leave their MCE0 bits set and do not generate interrupts on the reception of the following data bytes, thereby ignoring the data. Once the entire message is received, the addressed slave resets its MCE0 bit to ignore all transmissions until it receives the next address byte. Multiple addresses can be assigned to a single slave and/or a single address can be assigned to multiple slaves, thereby enabling "broadcast" transmissions to more than one slave simultaneously. The master processor can be configured to receive all transmissions or a protocol can be implemented such that the master/slave role is temporarily reversed to enable half-duplex transmission between the original master and slave(s). 293 Rev. 1.0 Si106x/108x Master Device RX TX Slave Device RX TX Slave Device RX TX Slave Device RX V+ TX Figure 29.6. UART Multi-Processor Mode Interconnect Diagram Rev. 1.0 294 Si106x/108x SFR Definition 29.1. SCON0: Serial Port 0 Control Bit 7 6 Name S0MODE Type R/W Reset 0 5 4 3 2 1 0 MCE0 REN0 TB80 RB80 TI0 RI0 R R/W R/W R/W R/W R/W R/W 1 0 0 0 0 0 0 SFR Page = 0x0; SFR Address = 0x98; Bit-Addressable Bit 7 Name Function S0MODE Serial Port 0 Operation Mode. Selects the UART0 Operation Mode. 0: 8-bit UART with Variable Baud Rate. 1: 9-bit UART with Variable Baud Rate. 6 Unused 5 MCE0 Read = 1b. Write = Don't Care. Multiprocessor Communication Enable. For Mode 0 (8-bit UART): Checks for valid stop bit. 0: Logic level of stop bit is ignored. 1: RI0 will only be activated if stop bit is logic level 1. For Mode 1 (9-bit UART): Multiprocessor Communications Enable. 0: Logic level of ninth bit is ignored. 1: RI0 is set and an interrupt is generated only when the ninth bit is logic 1. 4 REN0 Receive Enable. 0: UART0 reception disabled. 1: UART0 reception enabled. 3 TB80 Ninth Transmission Bit. The logic level of this bit will be sent as the ninth transmission bit in 9-bit UART Mode (Mode 1). Unused in 8-bit mode (Mode 0). 2 RB80 Ninth Receive Bit. RB80 is assigned the value of the STOP bit in Mode 0; it is assigned the value of the 9th data bit in Mode 1. 1 TI0 Transmit Interrupt Flag. Set by hardware when a byte of data has been transmitted by UART0 (after the 8th bit in 8-bit UART Mode, or at the beginning of the STOP bit in 9-bit UART Mode). When the UART0 interrupt is enabled, setting this bit causes the CPU to vector to the UART0 interrupt service routine. This bit must be cleared manually by software. 0 RI0 Receive Interrupt Flag. Set to 1 by hardware when a byte of data has been received by UART0 (set at the STOP bit sampling time). When the UART0 interrupt is enabled, setting this bit to 1 causes the CPU to vector to the UART0 interrupt service routine. This bit must be cleared manually by software. 295 Rev. 1.0 Si106x/108x SFR Definition 29.2. SBUF0: Serial (UART0) Port Data Buffer Bit 7 6 5 4 3 2 1 0 SBUF0[7:0] Name Type R/W R/W R/W R/W R/W R/W R/W R/W Reset 0 0 0 0 0 0 0 0 SFR Page = 0x0; SFR Address = 0x99 Bit Name 7:0 SBUF0 Function Serial Data Buffer Bits 7:0 (MSB-LSB) This SFR accesses two registers; a transmit shift register and a receive latch register. When data is written to SBUF0, it goes to the transmit shift register and is held for serial transmission. Writing a byte to SBUF0 initiates the transmission. A read of SBUF0 returns the contents of the receive latch. Rev. 1.0 296 Si106x/108x Table 29.1. Timer Settings for Standard Baud Rates Using The Internal 24.5 MHz Oscillator Frequency: 24.5 MHz SYSCLK from Internal Osc. Target Baud Rate (bps) 230400 115200 57600 28800 14400 9600 2400 1200 Baud Rate % Error -0.32% -0.32% 0.15% -0.32% 0.15% -0.32% -0.32% 0.15% Timer Clock Oscillator Source Divide Factor 106 212 426 848 1704 2544 10176 20448 SCA1-SCA0 (pre-scale select)1 SYSCLK SYSCLK SYSCLK SYSCLK/4 SYSCLK/12 SYSCLK/12 SYSCLK/48 SYSCLK/48 XX2 XX XX 01 00 00 10 10 T1M1 Timer 1 Reload Value (hex) 1 1 1 0 0 0 0 0 0xCB 0x96 0x2B 0x96 0xB9 0x96 0x96 0x2B Notes: 1. SCA1-SCA0 and T1M bit definitions can be found in Section 31.1. 2. X = Don't care. Table 29.2. Timer Settings for Standard Baud Rates Using an External 22.1184 MHz Oscillator Frequency: 22.1184 MHz SYSCLK from Internal Osc. SYSCLK from External Osc. Target Baud Rate (bps) 230400 115200 57600 28800 14400 9600 2400 1200 230400 115200 57600 28800 14400 9600 Baud Rate % Error 0.00% 0.00% 0.00% 0.00% 0.00% 0.00% 0.00% 0.00% 0.00% 0.00% 0.00% 0.00% 0.00% 0.00% Timer Clock SCA1-SCA0 Oscillator Source (pre-scale Divide select)1 Factor 96 192 384 768 1536 2304 9216 18432 96 192 384 768 1536 2304 SYSCLK SYSCLK SYSCLK SYSCLK / 12 SYSCLK / 12 SYSCLK / 12 SYSCLK / 48 SYSCLK / 48 EXTCLK / 8 EXTCLK / 8 EXTCLK / 8 EXTCLK / 8 EXTCLK / 8 EXTCLK / 8 Notes: 1. SCA1-SCA0 and T1M bit definitions can be found in Section 31.1. 2. X = Don't care. 297 Rev. 1.0 XX2 XX XX 00 00 00 10 10 11 11 11 11 11 11 T1M1 Timer 1 Reload Value (hex) 1 1 1 0 0 0 0 0 0 0 0 0 0 0 0xD0 0xA0 0x40 0xE0 0xC0 0xA0 0xA0 0x40 0xFA 0xF4 0xE8 0xD0 0xA0 0x70 Si106x/108x 30. Enhanced Serial Peripheral Interface (SPI0) The Enhanced Serial Peripheral Interface (SPI0) provides access to a flexible, full-duplex synchronous serial bus. SPI0 can operate as a master or slave device in both 3-wire or 4-wire modes, and supports multiple masters and slaves on a single SPI bus. The slave-select (NSS) signal can be configured as an input to select SPI0 in slave mode, or to disable Master Mode operation in a multi-master environment, avoiding contention on the SPI bus when more than one master attempts simultaneous data transfers. NSS can also be configured as a chip-select output in master mode, or disabled for 3-wire operation. Additional general purpose port I/O pins can be used to select multiple slave devices in master mode. SFR Bus SYSCLK SPI0CN SPIBSY MSTEN CKPHA CKPOL SLVSEL NSSIN SRMT RXBMT SPIF WCOL MODF RXOVRN NSSMD1 NSSMD0 TXBMT SPIEN SPI0CFG SCR7 SCR6 SCR5 SCR4 SCR3 SCR2 SCR1 SCR0 SPI0CKR Clock Divide Logic SPI CONTROL LOGIC Data Path Control SPI IRQ Pin Interface Control MOSI Tx Data SPI0DAT SCK Transmit Data Buffer Shift Register Rx Data 7 6 5 4 3 2 1 0 Receive Data Buffer Pin Control Logic MISO C R O S S B A R Port I/O NSS Read SPI0DAT Write SPI0DAT SFR Bus Figure 30.1. SPI Block Diagram Rev. 1.0 298 Si106x/108x 30.1. Signal Descriptions The four signals used by SPI0 (MOSI, MISO, SCK, NSS) are described below. 30.1.1. Master Out, Slave In (MOSI) The master-out, slave-in (MOSI) signal is an output from a master device and an input to slave devices. It is used to serially transfer data from the master to the slave. This signal is an output when SPI0 is operating as a master and an input when SPI0 is operating as a slave. Data is transferred most-significant bit first. When configured as a master, MOSI is driven by the MSB of the shift register in both 3- and 4-wire mode. 30.1.2. Master In, Slave Out (MISO) The master-in, slave-out (MISO) signal is an output from a slave device and an input to the master device. It is used to serially transfer data from the slave to the master. This signal is an input when SPI0 is operating as a master and an output when SPI0 is operating as a slave. Data is transferred mostsignificant bit first. The MISO pin is placed in a high-impedance state when the SPI module is disabled and when the SPI operates in 4-wire mode as a slave that is not selected. When acting as a slave in 3-wire mode, MISO is always driven by the MSB of the shift register. 30.1.3. Serial Clock (SCK) The serial clock (SCK) signal is an output from the master device and an input to slave devices. It is used to synchronize the transfer of data between the master and slave on the MOSI and MISO lines. SPI0 generates this signal when operating as a master. The SCK signal is ignored by a SPI slave when the slave is not selected (NSS = 1) in 4-wire slave mode. 30.1.4. Slave Select (NSS) The function of the slave-select (NSS) signal is dependent on the setting of the NSSMD1 and NSSMD0 bits in the SPI0CN register. There are three possible modes that can be selected with these bits: 1. NSSMD[1:0] = 00: 3-Wire Master or 3-Wire Slave Mode: SPI0 operates in 3-wire mode, and NSS is disabled. When operating as a slave device, SPI0 is always selected in 3-wire mode. Since no select signal is present, SPI0 must be the only slave on the bus in 3-wire mode. This is intended for point-topoint communication between a master and one slave. 2. NSSMD[1:0] = 01: 4-Wire Slave or Multi-Master Mode: SPI0 operates in 4-wire mode, and NSS is enabled as an input. When operating as a slave, NSS selects the SPI0 device. When operating as a master, a 1-to-0 transition of the NSS signal disables the master function of SPI0 so that multiple master devices can be used on the same SPI bus. 3. NSSMD[1:0] = 1x: 4-Wire Master Mode: SPI0 operates in 4-wire mode, and NSS is enabled as an output. The setting of NSSMD0 determines what logic level the NSS pin will output. This configuration should only be used when operating SPI0 as a master device. See Figure 30.2, Figure 30.3, and Figure 30.4 for typical connection diagrams of the various operational modes. Note that the setting of NSSMD bits affects the pinout of the device. When in 3-wire master or 3-wire slave mode, the NSS pin will not be mapped by the crossbar. In all other modes, the NSS signal will be mapped to a pin on the device. See Section "20. Si106x/108xPort Input/Output" on page 217 for general purpose port I/O and crossbar information. 30.2. SPI0 Master Mode Operation A SPI master device initiates all data transfers on a SPI bus. SPI0 is placed in master mode by setting the Master Enable flag (MSTEN, SPI0CN.6). Writing a byte of data to the SPI0 data register (SPI0DAT) when in master mode writes to the transmit buffer. If the SPI shift register is empty, the byte in the transmit buffer is moved to the shift register, and a data transfer begins. The SPI0 master immediately shifts out the data serially on the MOSI line while providing the serial clock on SCK. The SPIF (SPI0CN.7) flag is set to logic 1 at the end of the transfer. If interrupts are enabled, an interrupt request is generated when the SPIF flag is set. While the SPI0 master transfers data to a slave on the MOSI line, the addressed SPI slave device simultaneously transfers the contents of its shift register to the SPI master on the MISO line in a full-duplex 299 Rev. 1.0 Si106x/108x operation. Therefore, the SPIF flag serves as both a transmit-complete and receive-data-ready flag. The data byte received from the slave is transferred MSB-first into the master's shift register. When a byte is fully shifted into the register, it is moved to the receive buffer where it can be read by the processor by reading SPI0DAT. When configured as a master, SPI0 can operate in one of three different modes: multi-master mode, 3-wire single-master mode, and 4-wire single-master mode. The default, multi-master mode is active when NSSMD1 (SPI0CN.3) = 0 and NSSMD0 (SPI0CN.2) = 1. In this mode, NSS is an input to the device, and is used to disable the master SPI0 when another master is accessing the bus. When NSS is pulled low in this mode, MSTEN (SPI0CN.6) and SPIEN (SPI0CN.0) are set to 0 to disable the SPI master device, and a Mode Fault is generated (MODF, SPI0CN.5 = 1). Mode Fault will generate an interrupt if enabled. SPI0 must be manually re-enabled in software under these circumstances. In multi-master systems, devices will typically default to being slave devices while they are not acting as the system master device. In multimaster mode, slave devices can be addressed individually (if needed) using general-purpose I/O pins. Figure 30.2 shows a connection diagram between two master devices in multiple-master mode. 3-wire single-master mode is active when NSSMD1 (SPI0CN.3) = 0 and NSSMD0 (SPI0CN.2) = 0. In this mode, NSS is not used, and is not mapped to an external port pin through the crossbar. Any slave devices that must be addressed in this mode should be selected using general-purpose I/O pins. Figure 30.3 shows a connection diagram between a master device in 3-wire master mode and a slave device. 4-wire single-master mode is active when NSSMD1 (SPI0CN.3) = 1. In this mode, NSS is configured as an output pin, and can be used as a slave-select signal for a single SPI device. In this mode, the output value of NSS is controlled (in software) with the bit NSSMD0 (SPI0CN.2). Additional slave devices can be addressed using general-purpose I/O pins. Figure 30.4 shows a connection diagram for a master device in 4-wire master mode and two slave devices. Master Device 1 NSS GPIO MISO MISO MOSI MOSI SCK SCK GPIO NSS Master Device 2 Figure 30.2. Multiple-Master Mode Connection Diagram Master Device MISO MISO MOSI MOSI SCK SCK Slave Device Figure 30.3. 3-Wire Single Master and Slave Mode Connection Diagram Rev. 1.0 300 Si106x/108x Master Device GPIO MISO MISO MOSI MOSI SCK SCK NSS NSS MISO MOSI Slave Device Slave Device SCK NSS Figure 30.4. 4-Wire Single Master and Slave Mode Connection Diagram 30.3. SPI0 Slave Mode Operation When SPI0 is enabled and not configured as a master, it will operate as a SPI slave. As a slave, bytes are shifted in through the MOSI pin and out through the MISO pin by a master device controlling the SCK signal. A bit counter in the SPI0 logic counts SCK edges. When 8 bits have been shifted through the shift register, the SPIF flag is set to logic 1, and the byte is copied into the receive buffer. Data is read from the receive buffer by reading SPI0DAT. A slave device cannot initiate transfers. Data to be transferred to the master device is pre-loaded into the shift register by writing to SPI0DAT. Writes to SPI0DAT are doublebuffered, and are placed in the transmit buffer first. If the shift register is empty, the contents of the transmit buffer will immediately be transferred into the shift register. When the shift register already contains data, the SPI will load the shift register with the transmit buffer's contents after the last SCK edge of the next (or current) SPI transfer. When configured as a slave, SPI0 can be configured for 4-wire or 3-wire operation. The default, 4-wire slave mode, is active when NSSMD1 (SPI0CN.3) = 0 and NSSMD0 (SPI0CN.2) = 1. In 4-wire mode, the NSS signal is routed to a port pin and configured as a digital input. SPI0 is enabled when NSS is logic 0, and disabled when NSS is logic 1. The bit counter is reset on a falling edge of NSS. Note that the NSS signal must be driven low at least 2 system clocks before the first active edge of SCK for each byte transfer. Figure 30.4 shows a connection diagram between two slave devices in 4-wire slave mode and a master device. 3-wire slave mode is active when NSSMD1 (SPI0CN.3) = 0 and NSSMD0 (SPI0CN.2) = 0. NSS is not used in this mode, and is not mapped to an external port pin through the crossbar. Since there is no way of uniquely addressing the device in 3-wire slave mode, SPI0 must be the only slave device present on the bus. It is important to note that in 3-wire slave mode there is no external means of resetting the bit counter that determines when a full byte has been received. The bit counter can only be reset by disabling and reenabling SPI0 with the SPIEN bit. Figure 30.3 shows a connection diagram between a slave device in 3wire slave mode and a master device. 301 Rev. 1.0 Si106x/108x 30.4. SPI0 Interrupt Sources When SPI0 interrupts are enabled, the following four flags will generate an interrupt when they are set to logic 1: All of the following bits must be cleared by software. The SPI Interrupt Flag, SPIF (SPI0CN.7) is set to logic 1 at the end of each byte transfer. This flag can occur in all SPI0 modes. The Write Collision Flag, WCOL (SPI0CN.6) is set to logic 1 if a write to SPI0DAT is attempted when the transmit buffer has not been emptied to the SPI shift register. When this occurs, the write to SPI0DAT will be ignored, and the transmit buffer will not be written.This flag can occur in all SPI0 modes. The Mode Fault Flag MODF (SPI0CN.5) is set to logic 1 when SPI0 is configured as a master, and for multi-master mode and the NSS pin is pulled low. When a Mode Fault occurs, the MSTEN and SPIEN bits in SPI0CN are set to logic 0 to disable SPI0 and allow another master device to access the bus. The Receive Overrun Flag RXOVRN (SPI0CN.4) is set to logic 1 when configured as a slave, and a transfer is completed and the receive buffer still holds an unread byte from a previous transfer. The new byte is not transferred to the receive buffer, allowing the previously received data byte to be read. The data byte which caused the overrun is lost. Rev. 1.0 302 Si106x/108x 30.5. Serial Clock Phase and Polarity Four combinations of serial clock phase and polarity can be selected using the clock control bits in the SPI0 Configuration Register (SPI0CFG). The CKPHA bit (SPI0CFG.5) selects one of two clock phases (edge used to latch the data). The CKPOL bit (SPI0CFG.4) selects between an active-high or active-low clock. Both master and slave devices must be configured to use the same clock phase and polarity. SPI0 should be disabled (by clearing the SPIEN bit, SPI0CN.0) when changing the clock phase or polarity. The clock and data line relationships for master mode are shown in Figure 30.5. For slave mode, the clock and data relationships are shown in Figure 30.6 and Figure 30.7. Note that CKPHA should be set to 0 on both the master and slave SPI when communicating between two Silicon Labs C8051 devices. The SPI0 Clock Rate Register (SPI0CKR) as shown in SFR Definition 30.9 controls the master mode serial clock frequency. This register is ignored when operating in slave mode. When the SPI is configured as a master, the maximum data transfer rate (bits/sec) is one-half the system clock frequency or 12.5 MHz, whichever is slower. When the SPI is configured as a slave, the maximum data transfer rate (bits/sec) for full-duplex operation is 1/10 the system clock frequency, provided that the master issues SCK, NSS (in 4wire slave mode), and the serial input data synchronously with the slave's system clock. If the master issues SCK, NSS, and the serial input data asynchronously, the maximum data transfer rate (bits/sec) must be less than 1/10 the system clock frequency. In the special case where the master only wants to transmit data to the slave and does not need to receive data from the slave (i.e. half-duplex operation), the SPI slave can receive data at a maximum data transfer rate (bits/sec) of 1/4 the system clock frequency. This is provided that the master issues SCK, NSS, and the serial input data synchronously with the slave's system clock. SCK (CKPOL=0, CKPHA=0) SCK (CKPOL=0, CKPHA=1) SCK (CKPOL=1, CKPHA=0) SCK (CKPOL=1, CKPHA=1) MISO/MOSI MSB Bit 6 Bit 5 Bit 4 Bit 3 Bit 2 NSS (Must Remain High in Multi-Master Mode) Figure 30.5. Master Mode Data/Clock Timing 303 Rev. 1.0 Bit 1 Bit 0 Si106x/108x SCK (CKPOL=0, CKPHA=0) SCK (CKPOL=1, CKPHA=0) MOSI MSB Bit 6 Bit 5 Bit 4 Bit 3 Bit 2 Bit 1 Bit 0 MISO MSB Bit 6 Bit 5 Bit 4 Bit 3 Bit 2 Bit 1 Bit 0 NSS (4-Wire Mode) Figure 30.6. Slave Mode Data/Clock Timing (CKPHA = 0) SCK (CKPOL=0, CKPHA=1) SCK (CKPOL=1, CKPHA=1) MOSI MSB Bit 6 Bit 5 Bit 4 Bit 3 Bit 2 Bit 1 MISO MSB Bit 6 Bit 5 Bit 4 Bit 3 Bit 2 Bit 1 Bit 0 Bit 0 NSS (4-Wire Mode) Figure 30.7. Slave Mode Data/Clock Timing (CKPHA = 1) 30.6. SPI Special Function Registers SPI0 is accessed and controlled through four special function registers in the system controller: SPI0CN Control Register, SPI0DAT Data Register, SPI0CFG Configuration Register, and SPI0CKR Clock Rate Register. The four special function registers related to the operation of the SPI0 Bus are described in the following figures. Rev. 1.0 304 Si106x/108x SFR Definition 30.7. SPI0CFG: SPI0 Configuration Bit 7 6 5 4 3 2 1 0 Name SPIBSY MSTEN CKPHA CKPOL SLVSEL NSSIN SRMT RXBMT Type R R/W R/W R/W R R R R Reset 0 0 0 0 0 1 1 1 SFR Page = 0x0; SFR Address = 0xA1 Bit Name 7 SPIBSY Function SPI Busy. This bit is set to logic 1 when a SPI transfer is in progress (master or slave mode). 6 MSTEN Master Mode Enable. 0: Disable master mode. Operate in slave mode. 1: Enable master mode. Operate as a master. 5 CKPHA SPI0 Clock Phase. 0: Data centered on first edge of SCK period.* 1: Data centered on second edge of SCK period.* 4 CKPOL SPI0 Clock Polarity. 0: SCK line low in idle state. 1: SCK line high in idle state. 3 SLVSEL Slave Selected Flag. This bit is set to logic 1 whenever the NSS pin is low indicating SPI0 is the selected slave. It is cleared to logic 0 when NSS is high (slave not selected). This bit does not indicate the instantaneous value at the NSS pin, but rather a de-glitched version of the pin input. 2 NSSIN NSS Instantaneous Pin Input. This bit mimics the instantaneous value that is present on the NSS port pin at the time that the register is read. This input is not de-glitched. 1 SRMT Shift Register Empty (valid in slave mode only). This bit will be set to logic 1 when all data has been transferred in/out of the shift register, and there is no new information available to read from the transmit buffer or write to the receive buffer. It returns to logic 0 when a data byte is transferred to the shift register from the transmit buffer or by a transition on SCK. SRMT = 1 when in Master Mode. 0 RXBMT Receive Buffer Empty (valid in slave mode only). This bit will be set to logic 1 when the receive buffer has been read and contains no new information. If there is new information available in the receive buffer that has not been read, this bit will return to logic 0. RXBMT = 1 when in Master Mode. Note: In slave mode, data on MOSI is sampled in the center of each data bit. In master mode, data on MISO is sampled one SYSCLK before the end of each data bit, to provide maximum settling time for the slave device. See Table 30.1 for timing parameters. 305 Rev. 1.0 Si106x/108x SFR Definition 30.8. SPI0CN: SPI0 Control Bit 7 6 5 4 Name SPIF WCOL MODF RXOVRN Type R/W R/W R/W R/W Reset 0 0 0 0 SFR Page = 0x0; SFR Address = 0xF8; Bit-Addressable Bit Name 7 SPIF 3 2 1 0 NSSMD[1:0] TXBMT SPIEN R/W R R/W 1 0 0 1 Function SPI0 Interrupt Flag. This bit is set to logic 1 by hardware at the end of a data transfer. If SPI interrupts are enabled, an interrupt will be generated. This bit is not automatically cleared by hardware, and must be cleared by software. 6 WCOL Write Collision Flag. This bit is set to logic 1 if a write to SPI0DAT is attempted when TXBMT is 0. When this occurs, the write to SPI0DAT will be ignored, and the transmit buffer will not be written. If SPI interrupts are enabled, an interrupt will be generated. This bit is not automatically cleared by hardware, and must be cleared by software. 5 MODF Mode Fault Flag. This bit is set to logic 1 by hardware when a master mode collision is detected (NSS is low, MSTEN = 1, and NSSMD[1:0] = 01). If SPI interrupts are enabled, an interrupt will be generated. This bit is not automatically cleared by hardware, and must be cleared by software. 4 RXOVRN Receive Overrun Flag (valid in slave mode only). This bit is set to logic 1 by hardware when the receive buffer still holds unread data from a previous transfer and the last bit of the current transfer is shifted into the SPI0 shift register. If SPI interrupts are enabled, an interrupt will be generated. This bit is not automatically cleared by hardware, and must be cleared by software. 3:2 NSSMD[1:0] Slave Select Mode. Selects between the following NSS operation modes: (See Section 30.2 and Section 30.3). 00: 3-Wire Slave or 3-Wire Master Mode. NSS signal is not routed to a port pin. 01: 4-Wire Slave or Multi-Master Mode (Default). NSS is an input to the device. 1x: 4-Wire Single-Master Mode. NSS signal is mapped as an output from the device and will assume the value of NSSMD0. 1 TXBMT Transmit Buffer Empty. This bit will be set to logic 0 when new data has been written to the transmit buffer. When data in the transmit buffer is transferred to the SPI shift register, this bit will be set to logic 1, indicating that it is safe to write a new byte to the transmit buffer. 0 SPIEN SPI0 Enable. 0: SPI disabled. 1: SPI enabled. Rev. 1.0 306 Si106x/108x SFR Definition 30.9. SPI0CKR: SPI0 Clock Rate Bit 7 6 5 4 Name SCR[7:0] Type R/W Reset 0 0 0 0 SFR Page = 0x0; SFR Address = 0xA2 Bit Name 7:0 SCR[7:0] 3 2 1 0 0 0 0 0 Function SPI0 Clock Rate. These bits determine the frequency of the SCK output when the SPI0 module is configured for master mode operation. The SCK clock frequency is a divided version of the system clock, and is given in the following equation, where SYSCLK is the system clock frequency and SPI0CKR is the 8-bit value held in the SPI0CKR register. SYSCLK f SCK = ----------------------------------------------------------2 SPI0CKR[7:0] + 1 for 0 <= SPI0CKR <= 255 Example: If SYSCLK = 2 MHz and SPI0CKR = 0x04, 2000000 f SCK = -------------------------2 4 + 1 f SCK = 200kHz SFR Definition 30.10. SPI0DAT: SPI0 Data Bit 7 6 5 4 3 Name SPI0DAT[7:0] Type R/W Reset 0 0 0 0 SFR Page = 0x0; SFR Address = 0xA3 Bit Name 7:0 0 2 1 0 0 0 0 Function SPI0DAT[7:0] SPI0 Transmit and Receive Data. The SPI0DAT register is used to transmit and receive SPI0 data. Writing data to SPI0DAT places the data into the transmit buffer and initiates a transfer when in Master Mode. A read of SPI0DAT returns the contents of the receive buffer. 307 Rev. 1.0 Si106x/108x SCK* T T MCKH MCKL T T MIS MIH MISO MOSI * SCK is shown for CKPOL = 0. SCK is the opposite polarity for CKPOL = 1. Figure 30.8. SPI Master Timing (CKPHA = 0) SCK* T T MCKH MCKL T T MIS MIH MISO MOSI * SCK is shown for CKPOL = 0. SCK is the opposite polarity for CKPOL = 1. Figure 30.9. SPI Master Timing (CKPHA = 1) Rev. 1.0 308 Si106x/108x NSS T T SE T CKL SD SCK* T CKH T SIS T SIH MOSI T T SEZ T SOH SDZ MISO * SCK is shown for CKPOL = 0. SCK is the opposite polarity for CKPOL = 1. Figure 30.10. SPI Slave Timing (CKPHA = 0) NSS T T SE T CKL SD SCK* T CKH T SIS T SIH MOSI T SEZ T T SOH SLH MISO * SCK is shown for CKPOL = 0. SCK is the opposite polarity for CKPOL = 1. Figure 30.11. SPI Slave Timing (CKPHA = 1) 309 Rev. 1.0 T SDZ Si106x/108x Table 30.1. SPI Slave Timing Parameters Parameter Description Min Max Units Master Mode Timing (See Figure 30.8 and Figure 30.9) TMCKH SCK High Time 1 x TSYSCLK -- ns TMCKL SCK Low Time 1 x TSYSCLK -- ns TMIS MISO Valid to SCK Shift Edge 1 x TSYSCLK + 20 -- ns TMIH SCK Shift Edge to MISO Change 0 -- ns Slave Mode Timing (See Figure 30.10 and Figure 30.11) TSE NSS Falling to First SCK Edge 2 x TSYSCLK -- ns TSD Last SCK Edge to NSS Rising 2 x TSYSCLK -- ns TSEZ NSS Falling to MISO Valid -- 4 x TSYSCLK ns TSDZ NSS Rising to MISO High-Z -- 4 x TSYSCLK ns TCKH SCK High Time 5 x TSYSCLK -- ns TCKL SCK Low Time 5 x TSYSCLK -- ns TSIS MOSI Valid to SCK Sample Edge 2 x TSYSCLK -- ns TSIH SCK Sample Edge to MOSI Change 2 x TSYSCLK -- ns TSOH SCK Shift Edge to MISO Change -- 4 x TSYSCLK ns TSLH Last SCK Edge to MISO Change (CKPHA = 1 ONLY) 6 x TSYSCLK 8 x TSYSCLK ns Note: TSYSCLK is equal to one period of the device system clock (SYSCLK). Rev. 1.0 310 Si106x/108x 31. Timers Each MCU includes four counter/timers: two are 16-bit counter/timers compatible with those found in the standard 8051, and two are 16-bit auto-reload timer for use with the ADC, SMBus, or for general purpose use. These timers can be used to measure time intervals, count external events and generate periodic interrupt requests. Timer 0 and Timer 1 are nearly identical and have four primary modes of operation. Timer 2 and Timer 3 offer 16-bit and split 8-bit timer functionality with auto-reload. Additionally, Timer 2 and Timer 3 have a Capture Mode that can be used to measure the SmaRTClock or a Comparator period with respect to another oscillator. This is particularly useful when using Capacitive Touch Switches. See Application Note AN338 for details on Capacitive Touch Switch sensing. Timer 0 and Timer 1 Modes: Timer 2 Modes: Timer 3 Modes: 13-bit counter/timer 16-bit timer with auto-reload 16-bit timer with auto-reload Two 8-bit timers with auto-reload Two 8-bit timers with auto-reload 16-bit counter/timer 8-bit counter/timer with autoreload Two 8-bit counter/timers (Timer 0 only) Timers 0 and 1 may be clocked by one of five sources, determined by the Timer Mode Select bits (T1M- T0M) and the Clock Scale bits (SCA1-SCA0). The Clock Scale bits define a pre-scaled clock from which Timer 0 and/or Timer 1 may be clocked (See SFR Definition 31.1 for pre-scaled clock selection). Timer 0/1 may then be configured to use this pre-scaled clock signal or the system clock. Timer 2 and Timer 3 may be clocked by the system clock, the system clock divided by 12. Timer 2 may additionally be clocked by the SmaRTClock divided by 8 or the Comparator0 output. Timer 3 may additionally be clocked by the external oscillator clock source divided by 8 or the Comparator1 output. Timer 0 and Timer 1 may also be operated as counters. When functioning as a counter, a counter/timer register is incremented on each high-to-low transition at the selected input pin (T0 or T1). Events with a frequency of up to one-fourth the system clock frequency can be counted. The input signal need not be periodic, but it should be held at a given level for at least two full system clock cycles to ensure the level is properly sampled. Rev. 1.0 311 Si106x/108x SFR Definition 31.1. CKCON: Clock Control Bit 7 6 5 4 3 2 Name T3MH T3ML T2MH T2ML T1M T0M SCA[1:0] Type R/W R/W R/W R/W R/W R/W R/W Reset 0 0 0 0 0 0 SFR Page = 0x0; SFR Address = 0x8E Bit Name 7 T3MH 1 0 0 0 Function Timer 3 High Byte Clock Select. Selects the clock supplied to the Timer 3 high byte (split 8-bit timer mode only). 0: Timer 3 high byte uses the clock defined by the T3XCLK bit in TMR3CN. 1: Timer 3 high byte uses the system clock. 6 T3ML Timer 3 Low Byte Clock Select. Selects the clock supplied to Timer 3. Selects the clock supplied to the lower 8-bit timer in split 8-bit timer mode. 0: Timer 3 low byte uses the clock defined by the T3XCLK bit in TMR3CN. 1: Timer 3 low byte uses the system clock. 5 T2MH Timer 2 High Byte Clock Select. Selects the clock supplied to the Timer 2 high byte (split 8-bit timer mode only). 0: Timer 2 high byte uses the clock defined by the T2XCLK bit in TMR2CN. 1: Timer 2 high byte uses the system clock. 4 T2ML Timer 2 Low Byte Clock Select. Selects the clock supplied to Timer 2. If Timer 2 is configured in split 8-bit timer mode, this bit selects the clock supplied to the lower 8-bit timer. 0: Timer 2 low byte uses the clock defined by the T2XCLK bit in TMR2CN. 1: Timer 2 low byte uses the system clock. 3 T1M Timer 1 Clock Select. Selects the clock source supplied to Timer 1. Ignored when C/T1 is set to 1. 0: Timer 1 uses the clock defined by the prescale bits SCA[1:0]. 1: Timer 1 uses the system clock. 2 T0M Timer 0 Clock Select. Selects the clock source supplied to Timer 0. Ignored when C/T0 is set to 1. 0: Counter/Timer 0 uses the clock defined by the prescale bits SCA[1:0]. 1: Counter/Timer 0 uses the system clock. 1:0 SCA[1:0] Timer 0/1 Prescale Bits. These bits control the Timer 0/1 Clock Prescaler: 00: System clock divided by 12 01: System clock divided by 4 10: System clock divided by 48 11: External clock divided by 8 (synchronized with the system clock) 312 Rev. 1.0 Si106x/108x 31.1. Timer 0 and Timer 1 Each timer is implemented as a 16-bit register accessed as two separate bytes: a low byte (TL0 or TL1) and a high byte (TH0 or TH1). The Counter/Timer Control register (TCON) is used to enable Timer 0 and Timer 1 as well as indicate status. Timer 0 interrupts can be enabled by setting the ET0 bit in the IE register (Section "11.5. Interrupt Register Descriptions" on page 140); Timer 1 interrupts can be enabled by setting the ET1 bit in the IE register (Section "11.5. Interrupt Register Descriptions" on page 140). Both counter/timers operate in one of four primary modes selected by setting the Mode Select bits T1M1-T0M0 in the Counter/Timer Mode register (TMOD). Each timer can be configured independently. Each operating mode is described below. 31.1.1. Mode 0: 13-bit Counter/Timer Timer 0 and Timer 1 operate as 13-bit counter/timers in Mode 0. The following describes the configuration and operation of Timer 0. However, both timers operate identically, and Timer 1 is configured in the same manner as described for Timer 0. The TH0 register holds the eight MSBs of the 13-bit counter/timer. TL0 holds the five LSBs in bit positions TL0.4-TL0.0. The three upper bits of TL0 (TL0.7-TL0.5) are indeterminate and should be masked out or ignored when reading. As the 13-bit timer register increments and overflows from 0x1FFF (all ones) to 0x0000, the timer overflow flag TF0 (TCON.5) is set and an interrupt will occur if Timer 0 interrupts are enabled. The C/T0 bit (TMOD.2) selects the counter/timer's clock source. When C/T0 is set to logic 1, high-to-low transitions at the selected Timer 0 input pin (T0) increment the timer register (Refer to Section "20.3. Priority Crossbar Decoder" on page 221 for information on selecting and configuring external I/O pins). Clearing C/T selects the clock defined by the T0M bit (CKCON.3). When T0M is set, Timer 0 is clocked by the system clock. When T0M is cleared, Timer 0 is clocked by the source selected by the Clock Scale bits in CKCON (see SFR Definition 31.1). Setting the TR0 bit (TCON.4) enables the timer when either GATE0 (TMOD.3) is logic 0 or the input signal INT0 is active as defined by bit IN0PL in register IT01CF (see SFR Definition 11.7). Setting GATE0 to 1 allows the timer to be controlled by the external input signal INT0 (see Section "11.5. Interrupt Register Descriptions" on page 140), facilitating pulse width measurements Table 31.1. Timer 0 Running Modes TR0 GATE0 INT0 Counter/Timer 0 X X Disabled 1 0 X Enabled 1 1 0 Disabled 1 1 1 Enabled Note: X = Don't Care Setting TR0 does not force the timer to reset. The timer registers should be loaded with the desired initial value before the timer is enabled. TL1 and TH1 form the 13-bit register for Timer 1 in the same manner as described above for TL0 and TH0. Timer 1 is configured and controlled using the relevant TCON and TMOD bits just as with Timer 0. The input signal INT1 is used with Timer 1; the INT1 polarity is defined by bit IN1PL in register IT01CF (see SFR Definition 11.7). Rev. 1.0 313 Si106x/108x CKCON T 3 M H P re -s ca le d C lo c k 0 SYSCLK 1 T 3 M L T 2 M H TM OD T T T S S 2 1 0 C C MMM A A 1 0 L G A T E 1 C / T 1 T 1 M 1 T 1 M 0 G A T E 0 C / T 0 IT 0 1 C F T 0 M 1 T 0 M 0 I N 1 P L I N 1 S L 2 I N 1 S L 1 I N 1 S L 0 I N 0 P L I N 0 S L 2 I N 0 S L 1 I N 0 S L 0 0 1 TCLK TR0 C ro ss b a r IN T 0 TL0 (5 b its ) TH0 (8 b its) G ATE0 IN 0 P L TCON T0 TF1 TR1 TF0 TR0 IE 1 IT 1 IE 0 IT 0 Inte rru pt XOR Figure 31.1. T0 Mode 0 Block Diagram 31.1.2. Mode 1: 16-bit Counter/Timer Mode 1 operation is the same as Mode 0, except that the counter/timer registers use all 16 bits. The counter/timers are enabled and configured in Mode 1 in the same manner as for Mode 0. 31.1.3. Mode 2: 8-bit Counter/Timer with Auto-Reload Mode 2 configures Timer 0 and Timer 1 to operate as 8-bit counter/timers with automatic reload of the start value. TL0 holds the count and TH0 holds the reload value. When the counter in TL0 overflows from all ones to 0x00, the timer overflow flag TF0 (TCON.5) is set and the counter in TL0 is reloaded from TH0. If Timer 0 interrupts are enabled, an interrupt will occur when the TF0 flag is set. The reload value in TH0 is not changed. TL0 must be initialized to the desired value before enabling the timer for the first count to be correct. When in Mode 2, Timer 1 operates identically to Timer 0. Both counter/timers are enabled and configured in Mode 2 in the same manner as Mode 0. Setting the TR0 bit (TCON.4) enables the timer when either GATE0 (TMOD.3) is logic 0 or when the input signal INT0 is active as defined by bit IN0PL in register IT01CF (see Section "11.6. External Interrupts INT0 and INT1" on page 147 for details on the external input signals INT0 and INT1). 314 Rev. 1.0 Si106x/108x CKCON T T T T T T S 3 3 2 2 1 0 C MMMMMMA H L H L 1 Pre-scaled Clock TMOD S C A 0 G A T E 1 C / T 1 T 1 M 1 T 1 M 0 G A T E 0 C / T 0 IT01CF T 0 M 1 T 0 M 0 I N 1 P L I N 1 S L 2 I N 1 S L 1 I N 1 S L 0 I N 0 P L I N 0 S L 2 I N 0 S L 1 I N 0 S L 0 0 0 SYSCLK 1 1 T0 TL0 (8 bits) TCON TCLK TR0 Crossbar GATE0 TH0 (8 bits) INT0 IN0PL TF1 TR1 TF0 TR0 IE1 IT1 IE0 IT0 Interrupt Reload XOR Figure 31.2. T0 Mode 2 Block Diagram 31.1.4. Mode 3: Two 8-bit Counter/Timers (Timer 0 Only) In Mode 3, Timer 0 is configured as two separate 8-bit counter/timers held in TL0 and TH0. The counter/timer in TL0 is controlled using the Timer 0 control/status bits in TCON and TMOD: TR0, C/T0, GATE0 and TF0. TL0 can use either the system clock or an external input signal as its timebase. The TH0 register is restricted to a timer function sourced by the system clock or prescaled clock. TH0 is enabled using the Timer 1 run control bit TR1. TH0 sets the Timer 1 overflow flag TF1 on overflow and thus controls the Timer 1 interrupt. Timer 1 is inactive in Mode 3. When Timer 0 is operating in Mode 3, Timer 1 can be operated in Modes 0, 1 or 2, but cannot be clocked by external signals nor set the TF1 flag and generate an interrupt. However, the Timer 1 overflow can be used to generate baud rates for the SMBus and/or UART, and/or initiate ADC conversions. While Timer 0 is operating in Mode 3, Timer 1 run control is handled through its mode settings. To run Timer 1 while Timer 0 is in Mode 3, set the Timer 1 Mode as 0, 1, or 2. To disable Timer 1, configure it for Mode 3. Rev. 1.0 315 Si106x/108x CKCON T T T T T T S 3 3 2 2 1 0 C MMMMMMA H L H L 1 Pre-scaled Clock TMOD S C A 0 G A T E 1 C / T 1 T 1 M 1 T 1 M 0 G A T E 0 C / T 0 T 0 M 1 T 0 M 0 0 TR1 1 0 TCON SYSCLK TH0 (8 bits) 1 T0 TL0 (8 bits) TR0 Crossbar INT0 GATE0 IN0PL XOR Figure 31.3. T0 Mode 3 Block Diagram 316 Rev. 1.0 TF1 TR1 TF0 TR0 IE1 IT1 IE0 IT0 Interrupt Interrupt Si106x/108x SFR Definition 31.2. TCON: Timer Control Bit 7 6 5 4 3 2 1 0 Name TF1 TR1 TF0 TR0 IE1 IT1 IE0 IT0 Type R/W R/W R/W R/W R/W R/W R/W R/W Reset 0 0 0 0 0 0 0 0 SFR Page = 0x0; SFR Address = 0x88; Bit-Addressable Bit Name Function 7 TF1 Timer 1 Overflow Flag. Set to 1 by hardware when Timer 1 overflows. This flag can be cleared by software but is automatically cleared when the CPU vectors to the Timer 1 interrupt service routine. 6 TR1 Timer 1 Run Control. Timer 1 is enabled by setting this bit to 1. 5 TF0 Timer 0 Overflow Flag. Set to 1 by hardware when Timer 0 overflows. This flag can be cleared by software but is automatically cleared when the CPU vectors to the Timer 0 interrupt service routine. 4 TR0 Timer 0 Run Control. Timer 0 is enabled by setting this bit to 1. 3 IE1 External Interrupt 1. This flag is set by hardware when an edge/level of type defined by IT1 is detected. It can be cleared by software but is automatically cleared when the CPU vectors to the External Interrupt 1 service routine in edge-triggered mode. 2 IT1 Interrupt 1 Type Select. This bit selects whether the configured INT1 interrupt will be edge or level sensitive. INT1 is configured active low or high by the IN1PL bit in the IT01CF register (see SFR Definition 11.7). 0: INT1 is level triggered. 1: INT1 is edge triggered. 1 IE0 External Interrupt 0. This flag is set by hardware when an edge/level of type defined by IT1 is detected. It can be cleared by software but is automatically cleared when the CPU vectors to the External Interrupt 0 service routine in edge-triggered mode. 0 IT0 Interrupt 0 Type Select. This bit selects whether the configured INT0 interrupt will be edge or level sensitive. INT0 is configured active low or high by the IN0PL bit in register IT01CF (see SFR Definition 11.7). 0: INT0 is level triggered. 1: INT0 is edge triggered. Rev. 1.0 317 Si106x/108x SFR Definition 31.3. TMOD: Timer Mode Bit 7 6 Name GATE1 C/T1 Type R/W R/W Reset 0 0 5 4 3 2 T1M[1:0] GATE0 C/T0 T0M[1:0] R/W R/W R/W R/W 0 0 0 0 SFR Page = 0x0; SFR Address = 0x89 Bit Name 7 GATE1 1 0 0 0 Function Timer 1 Gate Control. 0: Timer 1 enabled when TR1 = 1 irrespective of INT1 logic level. 1: Timer 1 enabled only when TR1 = 1 AND INT1 is active as defined by bit IN1PL in register IT01CF (see SFR Definition 11.7). 6 C/T1 Counter/Timer 1 Select. 0: Timer: Timer 1 incremented by clock defined by T1M bit in register CKCON. 1: Counter: Timer 1 incremented by high-to-low transitions on external pin (T1). 5:4 T1M[1:0] Timer 1 Mode Select. These bits select the Timer 1 operation mode. 00: Mode 0, 13-bit Counter/Timer 01: Mode 1, 16-bit Counter/Timer 10: Mode 2, 8-bit Counter/Timer with Auto-Reload 11: Mode 3, Timer 1 Inactive 3 GATE0 Timer 0 Gate Control. 0: Timer 0 enabled when TR0 = 1 irrespective of INT0 logic level. 1: Timer 0 enabled only when TR0 = 1 AND INT0 is active as defined by bit IN0PL in register IT01CF (see SFR Definition 11.7). 2 C/T0 Counter/Timer 0 Select. 0: Timer: Timer 0 incremented by clock defined by T0M bit in register CKCON. 1: Counter: Timer 0 incremented by high-to-low transitions on external pin (T0). 1:0 T0M[1:0] Timer 0 Mode Select. These bits select the Timer 0 operation mode. 00: Mode 0, 13-bit Counter/Timer 01: Mode 1, 16-bit Counter/Timer 10: Mode 2, 8-bit Counter/Timer with Auto-Reload 11: Mode 3, Two 8-bit Counter/Timers 318 Rev. 1.0 Si106x/108x SFR Definition 31.4. TL0: Timer 0 Low Byte Bit 7 6 5 4 Name TL0[7:0] Type R/W Reset 0 0 0 0 SFR Page = 0x0; SFR Address = 0x8A Bit Name 7:0 TL0[7:0] 3 2 1 0 0 0 0 0 3 2 1 0 0 0 0 0 Function Timer 0 Low Byte. The TL0 register is the low byte of the 16-bit Timer 0. SFR Definition 31.5. TL1: Timer 1 Low Byte Bit 7 6 5 4 Name TL1[7:0] Type R/W Reset 0 0 0 0 SFR Page = 0x0; SFR Address = 0x8B Bit Name 7:0 TL1[7:0] Function Timer 1 Low Byte. The TL1 register is the low byte of the 16-bit Timer 1. Rev. 1.0 319 Si106x/108x SFR Definition 31.6. TH0: Timer 0 High Byte Bit 7 6 5 4 Name TH0[7:0] Type R/W Reset 0 0 0 0 SFR Page = 0x0; SFR Address = 0x8C Bit Name 7:0 TH0[7:0] 3 2 1 0 0 0 0 0 Function Timer 0 High Byte. The TH0 register is the high byte of the 16-bit Timer 0. SFR Definition 31.7. TH1: Timer 1 High Byte Bit 7 6 5 4 Name TH1[7:0] Type R/W Reset 0 0 0 0 SFR Page = 0x0; SFR Address = 0x8D Bit Name 7:0 TH1[7:0] 3 2 1 0 0 0 0 0 Function Timer 1 High Byte. The TH1 register is the high byte of the 16-bit Timer 1. 320 Rev. 1.0 Si106x/108x 31.2. Timer 2 Timer 2 is a 16-bit timer formed by two 8-bit SFRs: TMR2L (low byte) and TMR2H (high byte). Timer 2 may operate in 16-bit auto-reload mode or (split) 8-bit auto-reload mode. The T2SPLIT bit (TMR2CN.3) defines the Timer 2 operation mode. Timer 2 can also be used in Capture Mode to measure the SmaRTClock or the Comparator 0 period with respect to another oscillator. The ability to measure the Comparator 0 period with respect to the system clock is makes using Touch Sense Switches very easy. Timer 2 may be clocked by the system clock, the system clock divided by 12, SmaRTClock divided by 8, or Comparator 0 output. Note that the SmaRTClock divided by 8 and Comparator 0 output is synchronized with the system clock. 31.2.1. 16-bit Timer with Auto-Reload When T2SPLIT (TMR2CN.3) is zero, Timer 2 operates as a 16-bit timer with auto-reload. Timer 2 can be clocked by SYSCLK, SYSCLK divided by 12, SmaRTClock divided by 8, or Comparator 0 output. As the 16-bit timer register increments and overflows from 0xFFFF to 0x0000, the 16-bit value in the Timer 2 reload registers (TMR2RLH and TMR2RLL) is loaded into the Timer 2 register as shown in Figure 31.4, and the Timer 2 High Byte Overflow Flag (TMR2CN.7) is set. If Timer 2 interrupts are enabled (if IE.5 is set), an interrupt will be generated on each Timer 2 overflow. Additionally, if Timer 2 interrupts are enabled and the TF2LEN bit is set (TMR2CN.5), an interrupt will be generated each time the lower 8 bits (TMR2L) overflow from 0xFF to 0x00. CKCON T2XCLK[1:0] 00 SmaRTClock / 8 01 Comparator 0 11 TL2 Overflow 0 TR2 TCLK TMR2L To ADC, SMBus To SMBus TMR2H TMR2CN SYSCLK / 12 TTTTTTSS 3 3 2 2 1 0 CC MMMMMM A A HLHL 10 1 SYSCLK TF2H TF2L TF2LEN TF2CEN T2SPLIT TR2 Interrupt T2XCLK TMR2RLL TMR2RLH Reload Figure 31.4. Timer 2 16-Bit Mode Block Diagram 31.2.2. 8-bit Timers with Auto-Reload When T2SPLIT is set, Timer 2 operates as two 8-bit timers (TMR2H and TMR2L). Both 8-bit timers operate in auto-reload mode as shown in Figure 31.5. TMR2RLL holds the reload value for TMR2L; TMR2RLH holds the reload value for TMR2H. The TR2 bit in TMR2CN handles the run control for TMR2H. TMR2L is always running when configured for 8-bit Mode. Rev. 1.0 321 Si106x/108x Each 8-bit timer may be configured to use SYSCLK, SYSCLK divided by 12, SmaRTClock divided by 8 or Comparator 0 output. The Timer 2 Clock Select bits (T2MH and T2ML in CKCON) select either SYSCLK or the clock defined by the Timer 2 External Clock Select bits (T2XCLK[1:0] in TMR2CN), as follows: T2MH T2XCLK[1:0] TMR2H Clock Source T2ML T2XCLK[1:0] TMR2L Clock Source 0 00 SYSCLK / 12 0 00 SYSCLK / 12 0 01 SmaRTClock / 8 0 01 SmaRTClock / 8 0 10 Reserved 0 10 Reserved 0 11 Comparator 0 0 11 Comparator 0 1 X SYSCLK 1 X SYSCLK The TF2H bit is set when TMR2H overflows from 0xFF to 0x00; the TF2L bit is set when TMR2L overflows from 0xFF to 0x00. When Timer 2 interrupts are enabled (IE.5), an interrupt is generated each time TMR2H overflows. If Timer 2 interrupts are enabled and TF2LEN (TMR2CN.5) is set, an interrupt is generated each time either TMR2L or TMR2H overflows. When TF2LEN is enabled, software must check the TF2H and TF2L flags to determine the source of the Timer 2 interrupt. The TF2H and TF2L interrupt flags are not cleared by hardware and must be manually cleared by software. CKCON TTTTTTSS 3 3 2 2 1 0 CC MMMMMM A A HLHL 1 0 T2XCLK[1:0] SYSCLK / 12 00 SmaRTClock / 8 01 TMR2RLH Reload To SMBus 0 TCLK TR2 11 TMR2RLL SYSCLK Reload TMR2CN Comparator 0 TMR2H 1 TF2H TF2L TF2LEN TF2CEN T2SPLIT TR2 T2XCLK 1 TCLK TMR2L To ADC, SMBus 0 Figure 31.5. Timer 2 8-Bit Mode Block Diagram 322 Rev. 1.0 Interrupt Si106x/108x 31.2.3. Comparator 0/SmaRTClock Capture Mode The Capture Mode in Timer 2 allows either Comparator 0 or the SmaRTClock period to be measured against the system clock or the system clock divided by 12. Comparator 0 and the SmaRTClock period can also be compared against each other. Timer 2 Capture Mode is enabled by setting TF2CEN to 1. Timer 2 should be in 16-bit auto-reload mode when using Capture Mode. When Capture Mode is enabled, a capture event will be generated either every Comparator 0 rising edge or every 8 SmaRTClock clock cycles, depending on the T2XCLK1 setting. When the capture event occurs, the contents of Timer 2 (TMR2H:TMR2L) are loaded into the Timer 2 reload registers (TMR2RLH:TMR2RLL) and the TF2H flag is set (triggering an interrupt if Timer 2 interrupts are enabled). By recording the difference between two successive timer capture values, the Comparator 0 or SmaRTClock period can be determined with respect to the Timer 2 clock. The Timer 2 clock should be much faster than the capture clock to achieve an accurate reading. For example, if T2ML = 1b, T2XCLK1 = 0b, and TF2CEN = 1b, Timer 2 will clock every SYSCLK and capture every SmaRTClock clock divided by 8. If the SYSCLK is 24.5 MHz and the difference between two successive captures is 5984, then the SmaRTClock clock is as follows: 24.5 MHz/(5984/8) = 0.032754 MHz or 32.754 kHz. This mode allows software to determine the exact SmaRTClock frequency in self-oscillate mode and the time between consecutive Comparator 0 rising edges, which is useful for detecting changes in the capacitance of a Touch Sense Switch. T2XCLK[1:0] CKCON X0 Comparator 0 01 SmaRTClock/8 11 T2XCLK1 Comparator 0 TR2 TCLK TMR2L TMR2H Capture 1 SYSCLK SmaRTClock/8 0 TF2CEN TMR2RLL TMR2RLH TMR2CN SYSCLK/12 TTTTTTSS 3 3 2 2 1 0CC MMMMMM A A HLHL 1 0 0 TF2H TF2L TF2LEN TF2CEN T2SPLIT TR2 T2XCLK1 T2XCLK0 Interrupt 1 Figure 31.6. Timer 2 Capture Mode Block Diagram Rev. 1.0 323 Si106x/108x SFR Definition 31.8. TMR2CN: Timer 2 Control Bit 7 6 5 4 3 2 Name TF2H TF2L TF2LEN TF2CEN T2SPLIT TR2 T2XCLK[1:0] Type R/W R/W R/W R/W R/W R/W R/W Reset 0 0 0 0 0 0 SFR Page = 0x0; SFR Address = 0xC8; Bit-Addressable Bit Name 7 TF2H 1 0 0 0 Function Timer 2 High Byte Overflow Flag. Set by hardware when the Timer 2 high byte overflows from 0xFF to 0x00. In 16 bit mode, this will occur when Timer 2 overflows from 0xFFFF to 0x0000. When the Timer 2 interrupt is enabled, setting this bit causes the CPU to vector to the Timer 2 interrupt service routine. This bit is not automatically cleared by hardware. 6 TF2L Timer 2 Low Byte Overflow Flag. Set by hardware when the Timer 2 low byte overflows from 0xFF to 0x00. TF2L will be set when the low byte overflows regardless of the Timer 2 mode. This bit is not automatically cleared by hardware. 5 TF2LEN Timer 2 Low Byte Interrupt Enable. When set to 1, this bit enables Timer 2 Low Byte interrupts. If Timer 2 interrupts are also enabled, an interrupt will be generated when the low byte of Timer 2 overflows. 4 TF2CEN Timer 2 Capture Enable. When set to 1, this bit enables Timer 2 Capture Mode. 3 T2SPLIT Timer 2 Split Mode Enable. When set to 1, Timer 2 operates as two 8-bit timers with auto-reload. Otherwise, Timer 2 operates in 16-bit auto-reload mode. 2 TR2 Timer 2 Run Control. Timer 2 is enabled by setting this bit to 1. In 8-bit mode, this bit enables/disables TMR2H only; TMR2L is always enabled in split mode. 1:0 T2XCLK[1:0] Timer 2 External Clock Select. This bit selects the "external" and "capture trigger" clock sources for Timer 2. If Timer 2 is in 8-bit mode, this bit selects the "external" clock source for both timer bytes. Timer 2 Clock Select bits (T2MH and T2ML in register CKCON) may still be used to select between the "external" clock and the system clock for either timer. Note: External clock sources are synchronized with the system clock. 00: External Clock is SYSCLK/12. Capture trigger is SmaRTClock/8. 01: External Clock is Comparator 0. Capture trigger is SmaRTClock/8. 10: External Clock is SYSCLK/12. Capture trigger is Comparator 0. 11: External Clock is SmaRTClock/8. Capture trigger is Comparator 0. 324 Rev. 1.0 Si106x/108x SFR Definition 31.9. TMR2RLL: Timer 2 Reload Register Low Byte Bit 7 6 5 4 3 Name TMR2RLL[7:0] Type R/W Reset 0 0 0 0 0 SFR Page = 0x0; SFR Address = 0xCA Bit Name 7:0 2 1 0 0 0 0 2 1 0 0 0 0 Function TMR2RLL[7:0] Timer 2 Reload Register Low Byte. TMR2RLL holds the low byte of the reload value for Timer 2. SFR Definition 31.10. TMR2RLH: Timer 2 Reload Register High Byte Bit 7 6 5 4 3 Name TMR2RLH[7:0] Type R/W Reset 0 0 0 0 SFR Page = 0x0; SFR Address = 0xCB Bit Name 0 Function 7:0 TMR2RLH[7:0] Timer 2 Reload Register High Byte. TMR2RLH holds the high byte of the reload value for Timer 2. Rev. 1.0 325 Si106x/108x SFR Definition 31.11. TMR2L: Timer 2 Low Byte Bit 7 6 5 4 3 Name TMR2L[7:0] Type R/W Reset 0 0 0 0 0 SFR Page = 0x0; SFR Address = 0xCC Bit Name 7:0 2 1 0 0 0 0 Function TMR2L[7:0] Timer 2 Low Byte. In 16-bit mode, the TMR2L register contains the low byte of the 16-bit Timer 2. In 8bit mode, TMR2L contains the 8-bit low byte timer value. SFR Definition 31.12. TMR2H Timer 2 High Byte Bit 7 6 5 4 3 Name TMR2H[7:0] Type R/W Reset 0 0 0 0 SFR Page = 0x0; SFR Address = 0xCD Bit Name 7:0 0 2 1 0 0 0 0 Function TMR2H[7:0] Timer 2 Low Byte. In 16-bit mode, the TMR2H register contains the high byte of the 16-bit Timer 2. In 8bit mode, TMR2H contains the 8-bit high byte timer value. 326 Rev. 1.0 Si106x/108x 31.3. Timer 3 Timer 3 is a 16-bit timer formed by two 8-bit SFRs: TMR3L (low byte) and TMR3H (high byte). Timer 3 may operate in 16-bit auto-reload mode or (split) 8-bit auto-reload mode. The T3SPLIT bit (TMR3CN.3) defines the Timer 3 operation mode. Timer 3 can also be used in Capture Mode to measure the external oscillator source or the Comparator 1 period with respect to another oscillator. The ability to measure the Comparator 1 period with respect to the system clock is makes using Touch Sense Switches very easy. Timer 3 may be clocked by the system clock, the system clock divided by 12, external oscillator source divided by 8, or Comparator 1 output. The external oscillator source divided by 8 and Comparator 1 output is synchronized with the system clock. 31.3.1. 16-bit Timer with Auto-Reload When T3SPLIT (TMR3CN.3) is zero, Timer 3 operates as a 16-bit timer with auto-reload. Timer 3 can be clocked by SYSCLK, SYSCLK divided by 12, external oscillator clock source divided by 8, or Comparator 1 output. As the 16-bit timer register increments and overflows from 0xFFFF to 0x0000, the 16-bit value in the Timer 3 reload registers (TMR3RLH and TMR3RLL) is loaded into the Timer 3 register as shown in Figure 31.7, and the Timer 3 High Byte Overflow Flag (TMR3CN.7) is set. If Timer 3 interrupts are enabled (if EIE1.7 is set), an interrupt will be generated on each Timer 3 overflow. Additionally, if Timer 3 interrupts are enabled and the TF3LEN bit is set (TMR3CN.5), an interrupt will be generated each time the lower 8 bits (TMR3L) overflow from 0xFF to 0x00. CKCON TTTTTTSS 3 3 2 2 1 0CC MMMMMM A A HLHL 1 0 T3XCLK[1:0] SYSCLK / 12 00 External Clock / 8 01 SYSCLK / 12 10 Comparator 1 11 To ADC 0 TCLK TMR3L TMR3H TMR3CN TR3 1 SYSCLK TMR3RLL TMR3RLH TF3H TF3L TF3LEN TF3CEN T3SPLIT TR3 T3XCLK1 T3XCLK0 Interrupt Reload Figure 31.7. Timer 3 16-Bit Mode Block Diagram 31.3.2. 8-bit Timers with Auto-Reload When T3SPLIT is set, Timer 3 operates as two 8-bit timers (TMR3H and TMR3L). Both 8-bit timers operate in auto-reload mode as shown in Figure 31.8. TMR3RLL holds the reload value for TMR3L; TMR3RLH holds the reload value for TMR3H. The TR3 bit in TMR3CN handles the run control for TMR3H. TMR3L is always running when configured for 8-bit Mode. Rev. 1.0 327 Si106x/108x Each 8-bit timer may be configured to use SYSCLK, SYSCLK divided by 12, the external oscillator clock source divided by 8, or Comparator 1. The Timer 3 Clock Select bits (T3MH and T3ML in CKCON) select either SYSCLK or the clock defined by the Timer 3 External Clock Select bits (T3XCLK[1:0] in TMR3CN), as follows: T3MH T3XCLK[1:0] TMR3H Clock Source T3ML T3XCLK[1:0] TMR3L Clock Source 0 00 SYSCLK / 12 0 00 SYSCLK / 12 0 01 External Clock / 8 0 01 External Clock / 8 0 10 SYSCLK / 12 0 10 SYSCLK / 12 0 11 Comparator 1 0 11 Comparator 1 1 X SYSCLK 1 X SYSCLK The TF3H bit is set when TMR3H overflows from 0xFF to 0x00; the TF3L bit is set when TMR3L overflows from 0xFF to 0x00. When Timer 3 interrupts are enabled, an interrupt is generated each time TMR3H overflows. If Timer 3 interrupts are enabled and TF3LEN (TMR3CN.5) is set, an interrupt is generated each time either TMR3L or TMR3H overflows. When TF3LEN is enabled, software must check the TF3H and TF3L flags to determine the source of the Timer 3 interrupt. The TF3H and TF3L interrupt flags are not cleared by hardware and must be manually cleared by software. CKCON TT T TT TSS 3 3 2 2 1 0CC MMMMMM A A HLHL 1 0 T3XCLK[1:0] SYSCLK / 12 00 External Clock / 8 01 SYSCLK / 12 10 TMR3RLH Reload 0 TCLK TR3 TMR3H Comparator 1 11 TMR3RLL SYSCLK Reload TMR3CN 1 TF3H TF3L TF3LEN TF3CEN T3SPLIT TR3 T3XCLK1 T3XCLK0 1 TCLK TMR3L To ADC 0 Figure 31.8. Timer 3 8-Bit Mode Block Diagram. 328 Rev. 1.0 Interrupt Si106x/108x 31.3.3. Comparator 1/External Oscillator Capture Mode The Capture Mode in Timer 3 allows either Comparator 1 or the external oscillator period to be measured against the system clock or the system clock divided by 12. Comparator 1 and the external oscillator period can also be compared against each other. Setting TF3CEN to 1 enables the Comparator 1/External Oscillator Capture Mode for Timer 3. In this mode, T3SPLIT should be set to 0, as the full 16-bit timer is used. When Capture Mode is enabled, a capture event will be generated either every Comparator 1 rising edge or every 8 external clock cycles, depending on the T3XCLK1 setting. When the capture event occurs, the contents of Timer 3 (TMR3H:TMR3L) are loaded into the Timer 3 reload registers (TMR3RLH:TMR3RLL) and the TF3H flag is set (triggering an interrupt if Timer 3 interrupts are enabled). By recording the difference between two successive timer capture values, the Comparator 1 or external clock period can be determined with respect to the Timer 3 clock. The Timer 3 clock should be much faster than the capture clock to achieve an accurate reading. For example, if T3ML = 1b, T3XCLK1 = 0b, and TF3CEN = 1b, Timer 3 will clock every SYSCLK and capture every Comparator 1 rising edge. If SYSCLK is 24.5 MHz and the difference between two successive captures is 350 counts, then the Comparator 1 period is: 350 x (1 / 24.5 MHz) = 14.2 s. This mode allows software to determine the exact frequency of the external oscillator in C and RC mode or the time between consecutive Comparator 0 rising edges, which is useful for detecting changes in the capacitance of a Touch Sense Switch. T 3 X C L K [1 :0 ] CKCON SYSCLK / 12 00 E xte rn a l C lo ck / 8 01 SYSCLK / 12 10 C o m p a ra to r 1 11 T 3 M H T 3 M L T 2 M H T T T S S 2 1 0 C C MMM A A 1 0 L 0 TR3 SYSCLK 0 E xte rn a l C lo ck / 8 1 TM R3H TF3CEN TM R3RLL TM R3RLH TMR3CN C o m p a ra to r 1 TM R3L C a p tu re 1 T3XCLK1 TC LK T F 3H TF3L T F 3 LE N TF3CEN T 3 S P LIT TR3 T3XCLK1 T3XCLK0 In te rru p t Figure 31.9. Timer 3 Capture Mode Block Diagram Rev. 1.0 329 Si106x/108x SFR Definition 31.13. TMR3CN: Timer 3 Control Bit 7 6 5 4 3 2 Name TF3H TF3L TF3LEN TF3CEN T3SPLIT TR3 T3XCLK[1:0] Type R/W R/W R/W R/W R/W R/W R/W Reset 0 0 0 0 0 0 SFR Page = 0x0; SFR Address = 0x91 Bit Name 7 TF3H 1 0 0 0 Function Timer 3 High Byte Overflow Flag. Set by hardware when the Timer 3 high byte overflows from 0xFF to 0x00. In 16 bit mode, this will occur when Timer 3 overflows from 0xFFFF to 0x0000. When the Timer 3 interrupt is enabled, setting this bit causes the CPU to vector to the Timer 3 interrupt service routine. This bit is not automatically cleared by hardware. 6 TF3L Timer 3 Low Byte Overflow Flag. Set by hardware when the Timer 3 low byte overflows from 0xFF to 0x00. TF3L will be set when the low byte overflows regardless of the Timer 3 mode. This bit is not automatically cleared by hardware. 5 TF3LEN Timer 3 Low Byte Interrupt Enable. When set to 1, this bit enables Timer 3 Low Byte interrupts. If Timer 3 interrupts are also enabled, an interrupt will be generated when the low byte of Timer 3 overflows. 4 TF3CEN Timer 3 Comparator 1/External Oscillator Capture Enable. When set to 1, this bit enables Timer 3 Capture Mode. 3 T3SPLIT Timer 3 Split Mode Enable. When this bit is set, Timer 3 operates as two 8-bit timers with auto-reload. 0: Timer 3 operates in 16-bit auto-reload mode. 1: Timer 3 operates as two 8-bit auto-reload timers. 2 TR3 Timer 3 Run Control. Timer 3 is enabled by setting this bit to 1. In 8-bit mode, this bit enables/disables TMR3H only; TMR3L is always enabled in split mode. 1:0 T3XCLK[1:0] Timer 3 External Clock Select. This bit selects the "external" and "capture trigger" clock sources for Timer 3. If Timer 3 is in 8-bit mode, this bit selects the "external" clock source for both timer bytes. Timer 3 Clock Select bits (T3MH and T3ML in register CKCON) may still be used to select between the "external" clock and the system clock for either timer. Note: External clock sources are synchronized with the system clock. 00: External Clock is SYSCLK /12. Capture trigger is Comparator 1. 01: External Clock is External Oscillator/8. Capture trigger is Comparator 1. 10: External Clock is SYSCLK/12. Capture trigger is External Oscillator/8. 11: External Clock is Comparator 1. Capture trigger is External Oscillator/8. 330 Rev. 1.0 Si106x/108x SFR Definition 31.14. TMR3RLL: Timer 3 Reload Register Low Byte Bit 7 6 5 4 3 Name TMR3RLL[7:0] Type R/W Reset 0 0 0 0 0 SFR Page = 0x0; SFR Address = 0x92 Bit Name 7:0 2 1 0 0 0 0 2 1 0 0 0 0 Function TMR3RLL[7:0] Timer 3 Reload Register Low Byte. TMR3RLL holds the low byte of the reload value for Timer 3. SFR Definition 31.15. TMR3RLH: Timer 3 Reload Register High Byte Bit 7 6 5 4 3 Name TMR3RLH[7:0] Type R/W Reset 0 0 0 0 SFR Page = 0x0; SFR Address = 0x93 Bit Name 0 Function 7:0 TMR3RLH[7:0] Timer 3 Reload Register High Byte. TMR3RLH holds the high byte of the reload value for Timer 3. Rev. 1.0 331 Si106x/108x SFR Definition 31.16. TMR3L: Timer 3 Low Byte Bit 7 6 5 4 3 Name TMR3L[7:0] Type R/W Reset 0 0 0 0 0 SFR Page = 0x0; SFR Address = 0x94 Bit Name 7:0 TMR3L[7:0] 2 1 0 0 0 0 Function Timer 3 Low Byte. In 16-bit mode, the TMR3L register contains the low byte of the 16-bit Timer 3. In 8-bit mode, TMR3L contains the 8-bit low byte timer value. SFR Definition 31.17. TMR3H Timer 3 High Byte Bit 7 6 5 4 3 Name TMR3H[7:0] Type R/W Reset 0 0 0 0 SFR Page = 0x0; SFR Address = 0x95 Bit Name 7:0 TMR3H[7:0] 0 2 1 0 0 0 0 Function Timer 3 High Byte. In 16-bit mode, the TMR3H register contains the high byte of the 16-bit Timer 3. In 8-bit mode, TMR3H contains the 8-bit high byte timer value. 332 Rev. 1.0 Si106x/108x 32. Si106x/108xSi106x/108x Programmable Counter Array The Programmable Counter Array (PCA0) provides enhanced timer functionality while requiring less CPU intervention than the standard 8051 counter/timers. The PCA consists of a dedicated 16-bit counter/timer and six 16-bit capture/compare modules. Each capture/compare module has its own associated I/O line (CEXn) which is routed through the Crossbar to Port I/O when enabled. The counter/timer is driven by a programmable timebase that can select between the following sources: system clock, system clock divided by four, system clock divided by twelve, the external oscillator clock source divided by 8, Timer 0 overflows, or an external clock signal on the ECI input pin. Each capture/compare module may be configured to operate independently in one of six modes: Edge-Triggered Capture, Software Timer, High-Speed Output, Frequency Output, 8 to 11-Bit PWM, or 16-Bit PWM (each mode is described in Section "32.3. Capture/Compare Modules" on page 336). The external oscillator clock option is ideal for real-time clock (RTC) functionality, allowing the PCA to be clocked by a precision external oscillator while the internal oscillator drives the system clock. The PCA is configured and controlled through the system controller's Special Function Registers. The PCA block diagram is shown in Figure 32.1 Important Note: The PCA Module 5 may be used as a watchdog timer (WDT), and is enabled in this mode following a system reset. Access to certain PCA registers is restricted while WDT mode is enabled. See Section 32.4 for details. SYSCLK/12 SYSCLK/4 Timer 0 Overflow ECI SYSCLK PCA CLOCK MUX 16-Bit Counter/Timer External Clock/8 Capture/Compare Module 0 Capture/Compare Module 1 Capture/Compare Module 2 Capture/Compare Module 3 Capture/Compare Module 4 Capture/Compare Module 5 / WDT CEX5 CEX4 CEX3 CEX2 CEX1 CEX0 ECI Crossbar Port I/O Figure 32.1. PCA Block Diagram Rev. 1.0 333 Si106x/108x 32.1. PCA Counter/Timer The 16-bit PCA counter/timer consists of two 8-bit SFRs: PCA0L and PCA0H. PCA0H is the high byte (MSB) of the 16-bit counter/timer and PCA0L is the low byte (LSB). Reading PCA0L automatically latches the value of PCA0H into a "snapshot" register; the following PCA0H read accesses this "snapshot" register. Reading the PCA0L Register first guarantees an accurate reading of the entire 16-bit PCA0 counter. Reading PCA0H or PCA0L does not disturb the counter operation. The CPS2-CPS0 bits in the PCA0MD register select the timebase for the counter/timer as shown in Table 32.1. When the counter/timer overflows from 0xFFFF to 0x0000, the Counter Overflow Flag (CF) in PCA0MD is set to logic 1 and an interrupt request is generated if CF interrupts are enabled. Setting the ECF bit in PCA0MD to logic 1 enables the CF flag to generate an interrupt request. The CF bit is not automatically cleared by hardware when the CPU vectors to the interrupt service routine, and must be cleared by software. Clearing the CIDL bit in the PCA0MD register allows the PCA to continue normal operation while the CPU is in Idle mode. Table 32.1. PCA Timebase Input Options CPS2 CPS1 CPS0 Timebase 0 0 0 System clock divided by 12 0 0 1 System clock divided by 4 0 1 0 Timer 0 overflow 0 1 1 High-to-low transitions on ECI (max rate = system clock divided by 4) 1 0 0 System clock 1 0 1 External oscillator source divided by 8* 1 1 0 Reserved 1 1 1 Reserved Note: External oscillator source divided by 8 is synchronized with the system clock. IDLE PCA0MD C I D L WW D D T L E C K C P S 2 C P S 1 CE PC S F 0 PCA0CN CCC FRC F 5 C C F 4 C C F 3 C C F 2 C C F 1 C C F 0 To SFR Bus PCA0L read Snapshot Register SYSCLK/12 SYSCLK/4 Timer 0 Overflow ECI SYSCLK External Clock/8 000 001 010 0 1 PCA0H PCA0L Overflow 011 100 To PCA Modules 101 Figure 32.2. PCA Counter/Timer Block Diagram 334 To PCA Interrupt System CF Rev. 1.0 Si106x/108x 32.2. PCA0 Interrupt Sources Figure 32.3 shows a diagram of the PCA interrupt tree. There are eight independent event flags that can be used to generate a PCA0 interrupt. They are: the main PCA counter overflow flag (CF), which is set upon a 16-bit overflow of the PCA0 counter, an intermediate overflow flag (COVF), which can be set on an overflow from the 8th, 9th, 10th, or 11th bit of the PCA0 counter, and the individual flags for each PCA channel (CCF0, CCF1, CCF2, CCF3, CCF4, and CCF5), which are set according to the operation mode of that module. These event flags are always set when the trigger condition occurs. Each of these flags can be individually selected to generate a PCA0 interrupt, using the corresponding interrupt enable flag (ECF for CF, ECOV for COVF, and ECCFn for each CCFn). PCA0 interrupts must be globally enabled before any individual interrupt sources are recognized by the processor. PCA0 interrupts are globally enabled by setting the EA bit and the EPCA0 bit to logic 1. (for n = 0 to 5) PCA0CPMn PCA0CN P ECCMT P E WC A A AOWC MOPP TGMC 1 MP N n n n F 6 n n n n n CCCCCCCC FRCCCCCC FFFFFF 5 4 3 2 1 0 PCA0MD C WW I DD DT L LEC K PCA0PWM A CE ROC S VO EFV L CCCE PPPC SSSF 2 1 0 C L S E L 1 PCA Counter/Timer 8, 9, 10 or 11-bit Overflow C L S E L 0 Set 8, 9, 10, or 11 bit Operation 0 PCA Counter/Timer 16bit Overflow 0 1 1 ECCF0 PCA Module 0 (CCF0) EPCA0 EA 0 0 0 1 1 1 Interrupt Priority Decoder ECCF1 0 PCA Module 1 (CCF1) 1 ECCF2 0 PCA Module 2 (CCF2) 1 ECCF3 0 PCA Module 3 (CCF3) 1 ECCF4 0 PCA Module 4 (CCF4) 1 ECCF5 PCA Module 5 (CCF5) 0 1 Figure 32.3. PCA Interrupt Block Diagram Rev. 1.0 335 Si106x/108x 32.3. Capture/Compare Modules Each module can be configured to operate independently in one of six operation modes: edge-triggered capture, software timer, high speed output, frequency output, 8 to 11-bit pulse width modulator, or 16-bit pulse width modulator. Each module has Special Function Registers (SFRs) associated with it in the CIP51 system controller. These registers are used to exchange data with a module and configure the module's mode of operation. Table 32.2 summarizes the bit settings in the PCA0CPMn and PCA0PWM registers used to select the PCA capture/compare module's operating mode. Note that all modules set to use 8, 9, 10, or 11-bit PWM mode must use the same cycle length (8-11 bits). Setting the ECCFn bit in a PCA0CPMn register enables the module's CCFn interrupt. Table 32.2. PCA0CPM and PCA0PWM Bit Settings for PCA Capture/Compare Modules Operational Mode PCA0CPMn PCA0PWM Bit Number 7 6 5 4 3 2 1 0 7 6 5 4-2 Capture triggered by positive edge on CEXn X X 1 0 0 0 0 A 0 X B XXX XX Capture triggered by negative edge on CEXn X X 0 1 0 0 0 A 0 X B XXX XX Capture triggered by any transition on CEXn X X 1 1 0 0 0 A 0 X B XXX XX Software Timer X C 0 0 1 0 0 A 0 X B XXX XX High Speed Output X C 0 0 1 1 0 A 0 X B XXX XX Frequency Output X C 0 0 0 1 1 A 0 X B XXX XX 8-Bit Pulse Width Modulator (Note 7) 0 C 0 0 E 0 1 A 0 X B XXX 00 9-Bit Pulse Width Modulator (Note 7) 0 C 0 0 E 0 1 A D X B XXX 01 10-Bit Pulse Width Modulator (Note 7) 0 C 0 0 E 0 1 A D X B XXX 10 11-Bit Pulse Width Modulator (Note 7) 0 C 0 0 E 0 1 A D X B XXX 11 16-Bit Pulse Width Modulator 1 C 0 0 E 0 1 A 0 X B XXX XX 1-0 Notes: 1. X = Don't Care (no functional difference for individual module if 1 or 0). 2. A = Enable interrupts for this module (PCA interrupt triggered on CCFn set to 1). 3. B = Enable 8th, 9th, 10th or 11th bit overflow interrupt (Depends on setting of CLSEL[1:0]). 4. C = When set to 0, the digital comparator is off. For high speed and frequency output modes, the associated pin will not toggle. In any of the PWM modes, this generates a 0% duty cycle (output = 0). 5. D = Selects whether the Capture/Compare register (0) or the Auto-Reload register (1) for the associated channel is accessed via addresses PCA0CPHn and PCA0CPLn. 6. E = When set, a match event will cause the CCFn flag for the associated channel to be set. 7. All modules set to 8, 9, 10 or 11-bit PWM mode use the same cycle length setting. 336 Rev. 1.0 Si106x/108x 32.3.1. Edge-triggered Capture Mode In this mode, a valid transition on the CEXn pin causes the PCA to capture the value of the PCA counter/timer and load it into the corresponding module's 16-bit capture/compare register (PCA0CPLn and PCA0CPHn). The CAPPn and CAPNn bits in the PCA0CPMn register are used to select the type of transition that triggers the capture: low-to-high transition (positive edge), high-to-low transition (negative edge), or either transition (positive or negative edge). When a capture occurs, the Capture/Compare Flag (CCFn) in PCA0CN is set to logic 1. An interrupt request is generated if the CCFn interrupt for that module is enabled. The CCFn bit is not automatically cleared by hardware when the CPU vectors to the interrupt service routine, and must be cleared by software. If both CAPPn and CAPNn bits are set to logic 1, then the state of the Port pin associated with CEXn can be read directly to determine whether a rising-edge or falling-edge caused the capture. PCA Interrupt PCA0CPMn P ECCMT P E WC A A AOWC MOPP TGMC 1 MP N n n n F 6 n n n n n 0 0 0 x 0 Port I/O Crossbar CEXn CCC CCC FFF 2 1 0 (to CCFn) x x PCA0CN CC FR 1 PCA0CPLn PCA0CPHn Capture 0 1 PCA Timebase PCA0L PCA0H Figure 32.4. PCA Capture Mode Diagram Note: The CEXn input signal must remain high or low for at least 2 system clock cycles to be recognized by the hardware. Rev. 1.0 337 Si106x/108x 32.3.2. Software Timer (Compare) Mode In Software Timer mode, the PCA counter/timer value is compared to the module's 16-bit capture/compare register (PCA0CPHn and PCA0CPLn). When a match occurs, the Capture/Compare Flag (CCFn) in PCA0CN is set to logic 1. An interrupt request is generated if the CCFn interrupt for that module is enabled. The CCFn bit is not automatically cleared by hardware when the CPU vectors to the interrupt service routine, and must be cleared by software. Setting the ECOMn and MATn bits in the PCA0CPMn register enables Software Timer mode. Important Note About Capture/Compare Registers: When writing a 16-bit value to the PCA0 Capture/Compare registers, the low byte should always be written first. Writing to PCA0CPLn clears the ECOMn bit to 0; writing to PCA0CPHn sets ECOMn to 1. Write to PCA0CPLn 0 ENB Reset Write to PCA0CPHn PCA Interrupt ENB 1 PCA0CPMn P ECCMT P E WC A A AOWC MOPP TGMC 1 MP N n n n F 6 n n n n n x 0 0 PCA0CN PCA0CPLn CC FR PCA0CPHn 0 0 x Enable 16-bit Comparator PCA Timebase PCA0L Match PCA0H Figure 32.5. PCA Software Timer Mode Diagram 338 CCC CCC FFF 2 1 0 Rev. 1.0 0 1 Si106x/108x 32.3.3. High-Speed Output Mode In High-Speed Output mode, a module's associated CEXn pin is toggled each time a match occurs between the PCA Counter and the module's 16-bit capture/compare register (PCA0CPHn and PCA0CPLn). When a match occurs, the Capture/Compare Flag (CCFn) in PCA0CN is set to logic 1. An interrupt request is generated if the CCFn interrupt for that module is enabled. The CCFn bit is not automatically cleared by hardware when the CPU vectors to the interrupt service routine, and must be cleared by software. Setting the TOGn, MATn, and ECOMn bits in the PCA0CPMn register enables the HighSpeed Output mode. If ECOMn is cleared, the associated pin will retain its state, and not toggle on the next match event. Important Note About Capture/Compare Registers: When writing a 16-bit value to the PCA0 Capture/Compare registers, the low byte should always be written first. Writing to PCA0CPLn clears the ECOMn bit to 0; writing to PCA0CPHn sets ECOMn to 1. Write to PCA0CPLn 0 ENB Reset Write to PCA0CPHn PCA0CPMn P ECCMT P E WC A A AOWC MOPP TGMC 1 MPN n n n F 6 n n n n n ENB 1 x 0 0 0 x PCA Interrupt PCA0CN PCA0CPLn Enable CC FR PCA0CPHn 16-bit Comparator Match 0 1 Toggle PCA Timebase CCC CCC FFF 2 1 0 TOGn 0 CEXn 1 PCA0L Crossbar Port I/O PCA0H Figure 32.6. PCA High-Speed Output Mode Diagram Rev. 1.0 339 Si106x/108x 32.3.4. Frequency Output Mode Frequency Output Mode produces a programmable-frequency square wave on the module's associated CEXn pin. The capture/compare module high byte holds the number of PCA clocks to count before the output is toggled. The frequency of the square wave is then defined by Equation 32.1. F PCA F CEXn = ----------------------------------------2 PCA0CPHn Note: A value of 0x00 in the PCA0CPHn register is equal to 256 for this equation. Equation 32.1. Square Wave Frequency Output Where FPCA is the frequency of the clock selected by the CPS2-0 bits in the PCA mode register, PCA0MD. The lower byte of the capture/compare module is compared to the PCA counter low byte; on a match, CEXn is toggled and the offset held in the high byte is added to the matched value in PCA0CPLn. Frequency Output Mode is enabled by setting the ECOMn, TOGn, and PWMn bits in the PCA0CPMn register. Note that the MATn bit should normally be set to 0 in this mode. If the MATn bit is set to 1, the CCFn flag for the channel will be set when the 16-bit PCA0 counter and the 16-bit capture/compare register for the channel are equal. Write to PCA0CPLn 0 ENB Reset PCA0CPMn Write to PCA0CPHn ENB 1 P ECCMT P E WC A A AOWC MOPP TGMC 1 MP N n n n F 6 n n n n n x 0 0 0 PCA0CPLn 8-bit Adder Adder Enable Toggle x Enable PCA Timebase 8-bit Comparator PCA0CPHn TOGn match 0 CEXn 1 Crossbar Port I/O PCA0L Figure 32.7. PCA Frequency Output Mode 32.3.5. 8-Bit, 9-Bit, 10-Bit and 11-Bit Pulse Width Modulator Modes Each module can be used independently to generate a pulse width modulated (PWM) output on its associated CEXn pin. The frequency of the output is dependent on the timebase for the PCA counter/timer, and the setting of the PWM cycle length (8, 9, 10 or 11-bits). For backwards-compatibility with the 8-bit PWM mode available on other devices, the 8-bit PWM mode operates slightly different than 9, 10 and 11-bit PWM modes. It is important to note that all channels configured for 8/9/10/11-bit PWM mode will use the same cycle length. It is not possible to configure one channel for 8-bit PWM mode and another for 11bit mode (for example). However, other PCA channels can be configured to Pin Capture, High-Speed Output, Software Timer, Frequency Output, or 16-bit PWM mode independently. 340 Rev. 1.0 Si106x/108x 32.3.5.1. 8-Bit Pulse Width Modulator Mode The duty cycle of the PWM output signal in 8-bit PWM mode is varied using the module's PCA0CPLn capture/compare register. When the value in the low byte of the PCA counter/timer (PCA0L) is equal to the value in PCA0CPLn, the output on the CEXn pin will be set. When the count value in PCA0L overflows, the CEXn output will be reset (see Figure 32.8). Also, when the counter/timer low byte (PCA0L) overflows from 0xFF to 0x00, PCA0CPLn is reloaded automatically with the value stored in the module's capture/compare high byte (PCA0CPHn) without software intervention. Setting the ECOMn and PWMn bits in the PCA0CPMn register, and setting the CLSEL bits in register PCA0PWM to 00b enables 8-Bit Pulse Width Modulator mode. If the MATn bit is set to 1, the CCFn flag for the module will be set each time an 8-bit comparator match (rising edge) occurs. The COVF flag in PCA0PWM can be used to detect the overflow (falling edge), which will occur every 256 PCA clock cycles. The duty cycle for 8-Bit PWM Mode is given in Equation 32.2. Important Note About Capture/Compare Registers: When writing a 16-bit value to the PCA0 Capture/Compare registers, the low byte should always be written first. Writing to PCA0CPLn clears the ECOMn bit to 0; writing to PCA0CPHn sets ECOMn to 1. 256 - PCA0CPHn Duty Cycle = --------------------------------------------------256 Equation 32.2. 8-Bit PWM Duty Cycle Using Equation 32.2, the largest duty cycle is 100% (PCA0CPHn = 0), and the smallest duty cycle is 0.39% (PCA0CPHn = 0xFF). A 0% duty cycle may be generated by clearing the ECOMn bit to 0. Write to PCA0CPLn 0 ENB Reset PCA0CPHn Write to PCA0CPHn ENB COVF 1 PCA0PWM A R S E L EC CO OV VF 0 x C L S E L 1 PCA0CPMn C L S E L 0 0 0 P ECCMT P E WC A A AOWC MOPP TGMC 1 MP N n n n F 6 n n n n n 0 0 0 x 0 PCA0CPLn x Enable 8-bit Comparator match S R PCA Timebase PCA0L SET CLR Q CEXn Crossbar Port I/O Q Overflow Figure 32.8. PCA 8-Bit PWM Mode Diagram Rev. 1.0 341 Si106x/108x 32.3.5.2. 9/10/11-bit Pulse Width Modulator Mode The duty cycle of the PWM output signal in 9/10/11-bit PWM mode should be varied by writing to an "AutoReload" Register, which is dual-mapped into the PCA0CPHn and PCA0CPLn register locations. The data written to define the duty cycle should be right-justified in the registers. The auto-reload registers are accessed (read or written) when the bit ARSEL in PCA0PWM is set to 1. The capture/compare registers are accessed when ARSEL is set to 0. When the least-significant N bits of the PCA0 counter match the value in the associated module's capture/compare register (PCA0CPn), the output on CEXn is asserted high. When the counter overflows from the Nth bit, CEXn is asserted low (see Figure 32.9). Upon an overflow from the Nth bit, the COVF flag is set, and the value stored in the module's auto-reload register is loaded into the capture/compare register. The value of N is determined by the CLSEL bits in register PCA0PWM. The 9, 10 or 11-bit PWM mode is selected by setting the ECOMn and PWMn bits in the PCA0CPMn register, and setting the CLSEL bits in register PCA0PWM to the desired cycle length (other than 8-bits). If the MATn bit is set to 1, the CCFn flag for the module will be set each time a comparator match (rising edge) occurs. The COVF flag in PCA0PWM can be used to detect the overflow (falling edge), which will occur every 512 (9-bit), 1024 (10-bit) or 2048 (11-bit) PCA clock cycles. The duty cycle for 9/10/11-Bit PWM Mode is given in Equation 32.2, where N is the number of bits in the PWM cycle. Important Note About PCA0CPHn and PCA0CPLn Registers: When writing a 16-bit value to the PCA0CPn registers, the low byte should always be written first. Writing to PCA0CPLn clears the ECOMn bit to 0; writing to PCA0CPHn sets ECOMn to 1. 2 N - PCA0CPn Duty Cycle = ------------------------------------------2N Equation 32.3. 9, 10, and 11-Bit PWM Duty Cycle A 0% duty cycle may be generated by clearing the ECOMn bit to 0. Write to PCA0CPLn 0 R/W when ARSEL = 1 ENB Reset Write to PCA0CPHn (Auto-Reload) PCA0PWM PCA0CPH:Ln A R S E L (right-justified) ENB 1 C L S E L 1 EC CO OV VF PCA0CPMn P ECCMT P E WC A A AOWC MOPP TGMC 1 MP N n n n F 6 n n n n n 0 0 0 x 0 R/W when ARSEL = 0 C L S E L 0 x (Capture/Compare) Set "N" bits: 01 = 9 bits 10 = 10 bits 11 = 11 bits PCA0CPH:Ln (right-justified) x Enable N-bit Comparator match S R PCA Timebase SET CLR Q CEXn Crossbar Q PCA0H:L Overflow of Nth Bit Figure 32.9. PCA 9, 10 and 11-Bit PWM Mode Diagram 342 Rev. 1.0 Port I/O Si106x/108x 32.3.6. 16-Bit Pulse Width Modulator Mode A PCA module may also be operated in 16-Bit PWM mode. 16-bit PWM mode is independent of the other (8/9/10/11-bit) PWM modes. In this mode, the 16-bit capture/compare module defines the number of PCA clocks for the low time of the PWM signal. When the PCA counter matches the module contents, the output on CEXn is asserted high; when the 16-bit counter overflows, CEXn is asserted low. To output a varying duty cycle, new value writes should be synchronized with PCA CCFn match interrupts. 16-Bit PWM Mode is enabled by setting the ECOMn, PWMn, and PWM16n bits in the PCA0CPMn register. For a varying duty cycle, match interrupts should be enabled (ECCFn = 1 AND MATn = 1) to help synchronize the capture/compare register writes. If the MATn bit is set to 1, the CCFn flag for the module will be set each time a 16-bit comparator match (rising edge) occurs. The CF flag in PCA0CN can be used to detect the overflow (falling edge). The duty cycle for 16-Bit PWM Mode is given by Equation 32.4. Important Note About Capture/Compare Registers: When writing a 16-bit value to the PCA0 Capture/Compare registers, the low byte should always be written first. Writing to PCA0CPLn clears the ECOMn bit to 0; writing to PCA0CPHn sets ECOMn to 1. 65536 - PCA0CPn Duty Cycle = ----------------------------------------------------65536 Equation 32.4. 16-Bit PWM Duty Cycle Using Equation 32.4, the largest duty cycle is 100% (PCA0CPn = 0), and the smallest duty cycle is 0.0015% (PCA0CPn = 0xFFFF). A 0% duty cycle may be generated by clearing the ECOMn bit to 0. Write to PCA0CPLn 0 ENB Reset Write to PCA0CPHn ENB 1 PCA0CPMn P EC WCA MOP 1 MP 6 n n n 1 C A P N n MT P AOW TGM n n n 0 0 x 0 E C C F n PCA0CPHn PCA0CPLn x Enable 16-bit Comparator match S R PCA Timebase PCA0H PCA0L SET CLR Q CEXn Crossbar Port I/O Q Overflow Figure 32.10. PCA 16-Bit PWM Mode Rev. 1.0 343 Si106x/108x 32.4. Watchdog Timer Mode A programmable watchdog timer (WDT) function is available through the PCA Module 5. The WDT is used to generate a reset if the time between writes to the WDT update register (PCA0CPH5) exceed a specified limit. The WDT can be configured and enabled/disabled as needed by software. With the WDTE bit set in the PCA0MD register, Module 5 operates as a watchdog timer (WDT). The Module 5 high byte is compared to the PCA counter high byte; the Module 5 low byte holds the offset to be used when WDT updates are performed. The Watchdog Timer is enabled on reset. Writes to some PCA registers are restricted while the Watchdog Timer is enabled. The WDT will generate a reset shortly after code begins execution. To avoid this reset, the WDT should be explicitly disabled (and optionally re-configured and re-enabled if it is used in the system). 32.4.1. Watchdog Timer Operation While the WDT is enabled: PCA counter is forced on. Writes to PCA0L and PCA0H are not allowed. PCA clock source bits (CPS2-CPS0) are frozen. PCA Idle control bit (CIDL) is frozen. Module 5 is forced into software timer mode. Writes to the Module 5 mode register (PCA0CPM5) are disabled. While the WDT is enabled, writes to the CR bit will not change the PCA counter state; the counter will run until the WDT is disabled. The PCA counter run control bit (CR) will read zero if the WDT is enabled but user software has not enabled the PCA counter. If a match occurs between PCA0CPH5 and PCA0H while the WDT is enabled, a reset will be generated. To prevent a WDT reset, the WDT may be updated with a write of any value to PCA0CPH5. Upon a PCA0CPH5 write, PCA0H plus the offset held in PCA0CPL5 is loaded into PCA0CPH5 (See Figure 32.11). PCA 0M D C I D L W D T E W D L C K C P S 2 C P S 1 C E P C S F 0 PCA0CPH 5 Enable PCA0CPL5 8-bit Adder W rite to (PCA0CPH5) 8-bit Com parator PCA 0H M atch Reset PCA0L O verflow Adder Enable Figure 32.11. PCA Module 5 with Watchdog Timer Enabled Note that the 8-bit offset held in PCA0CPH5 is compared to the upper byte of the 16-bit PCA counter. This offset value is the number of PCA0L overflows before a reset. Up to 256 PCA clocks may pass before the first PCA0L overflow occurs, depending on the value of the PCA0L when the update is performed. The total offset is then given (in PCA clocks) by Equation 32.5, where PCA0L is the value of the PCA0L register at the time of the update. 344 Rev. 1.0 Si106x/108x Offset = 256 PCA0CPL5 + 256 - PCA0L Equation 32.5. Watchdog Timer Offset in PCA Clocks The WDT reset is generated when PCA0L overflows while there is a match between PCA0CPH5 and PCA0H. Software may force a WDT reset by writing a 1 to the CCF5 flag (PCA0CN.5) while the WDT is enabled. 32.4.2. Watchdog Timer Usage To configure the WDT, perform the following tasks: Disable the WDT by writing a 0 to the WDTE bit. Select the desired PCA clock source (with the CPS2-CPS0 bits). Load PCA0CPL5 with the desired WDT update offset value. Configure the PCA Idle mode (set CIDL if the WDT should be suspended while the CPU is in Idle mode). Enable the WDT by setting the WDTE bit to 1. Reset the WDT timer by writing to PCA0CPH5. The PCA clock source and Idle mode select cannot be changed while the WDT is enabled. The watchdog timer is enabled by setting the WDTE or WDLCK bits in the PCA0MD register. When WDLCK is set, the WDT cannot be disabled until the next system reset. If WDLCK is not set, the WDT is disabled by clearing the WDTE bit. The WDT is enabled following any reset. The PCA0 counter clock defaults to the system clock divided by 12, PCA0L defaults to 0x00, and PCA0CPL5 defaults to 0x00. Using Equation 32.5, this results in a WDT timeout interval of 256 PCA clock cycles, or 3072 system clock cycles. Table 32.3 lists some example timeout intervals for typical system clocks. Table 32.3. Watchdog Timer Timeout Intervals1 System Clock (Hz) PCA0CPL5 Timeout Interval (ms) 24,500,000 255 32.1 24,500,000 128 16.2 24,500,000 32 4.1 3,062,5002 255 257 2 128 129.5 2 3,062,500 32 33.1 32,000 255 24576 32,000 128 12384 32,000 32 3168 3,062,500 Notes: 1. Assumes SYSCLK/12 as the PCA clock source, and a PCA0L value of 0x00 at the update time. 2. Internal SYSCLK reset frequency = Internal Oscillator divided by 8. Rev. 1.0 345 Si106x/108x 32.5. Register Descriptions for PCA0 Following are detailed descriptions of the special function registers related to the operation of the PCA. SFR Definition 32.1. PCA0CN: PCA Control Bit 7 6 5 4 3 2 1 0 Name CF CR CCF5 CCF4 CCF3 CCF2 CCF1 CCF0 Type R/W R/W R/W R/W R/W R/W R/W R/W Reset 0 0 0 0 0 0 0 0 SFR Page = 0x0; SFR Address = 0xD8; Bit-Addressable Bit Name Function 7 CF PCA Counter/Timer Overflow Flag. Set by hardware when the PCA Counter/Timer overflows from 0xFFFF to 0x0000. When the Counter/Timer Overflow (CF) interrupt is enabled, setting this bit causes the CPU to vector to the PCA interrupt service routine. This bit is not automatically cleared by hardware and must be cleared by software. 6 CR PCA Counter/Timer Run Control. This bit enables/disables the PCA Counter/Timer. 0: PCA Counter/Timer disabled. 1: PCA Counter/Timer enabled. 5:0 CCF[5:0] PCA Module n Capture/Compare Flag. These bits are set by hardware when a match or capture occurs in the associated PCA Module n. When the CCFn interrupt is enabled, setting this bit causes the CPU to vector to the PCA interrupt service routine. This bit is not automatically cleared by hardware and must be cleared by software. 346 Rev. 1.0 Si106x/108x SFR Definition 32.2. PCA0MD: PCA Mode Bit 7 6 5 Name CIDL WDTE WDLCK Type R/W R/W R/W Reset 0 1 0 4 3 2 1 0 CPS2 CPS1 CPS0 ECF R R/W R/W R/W R/W 0 0 0 0 0 SFR Page = 0x0; SFR Address = 0xD9 Bit Name 7 CIDL Function PCA Counter/Timer Idle Control. Specifies PCA behavior when CPU is in Idle Mode. 0: PCA continues to function normally while the system controller is in Idle Mode. 1: PCA operation is suspended while the system controller is in Idle Mode. 6 WDTE Watchdog Timer Enable. If this bit is set, PCA Module 2 is used as the watchdog timer. 0: Watchdog Timer disabled. 1: PCA Module 2 enabled as Watchdog Timer. 5 WDLCK Watchdog Timer Lock. This bit locks/unlocks the Watchdog Timer Enable. When WDLCK is set, the Watchdog Timer may not be disabled until the next system reset. 0: Watchdog Timer Enable unlocked. 1: Watchdog Timer Enable locked. 4 3:1 Unused Read = 0b, Write = don't care. CPS[2:0] PCA Counter/Timer Pulse Select. These bits select the timebase source for the PCA counter 000: System clock divided by 12 001: System clock divided by 4 010: Timer 0 overflow 011: High-to-low transitions on ECI (max rate = system clock divided by 4) 100: System clock 101: External clock divided by 8 (synchronized with the system clock) 110: Reserved 111: Reserved 0 ECF PCA Counter/Timer Overflow Interrupt Enable. This bit sets the masking of the PCA Counter/Timer Overflow (CF) interrupt. 0: Disable the CF interrupt. 1: Enable a PCA Counter/Timer Overflow interrupt request when CF (PCA0CN.7) is set. Note: When the WDTE bit is set to 1, the other bits in the PCA0MD register cannot be modified. To change the contents of the PCA0MD register, the Watchdog Timer must first be disabled. Rev. 1.0 347 Si106x/108x SFR Definition 32.3. PCA0PWM: PCA PWM Configuration Bit 7 6 5 4 Name ARSEL ECOV COVF Type R/W R/W R/W R R R Reset 0 0 0 0 0 0 ARSEL 2 1 0 CLSEL[1:0] SFR Page = 0x0; SFR Address = 0xDF Bit Name 7 3 R/W 0 0 Function Auto-Reload Register Select. This bit selects whether to read and write the normal PCA capture/compare registers (PCA0CPn), or the Auto-Reload registers at the same SFR addresses. This function is used to define the reload value for 9, 10, and 11-bit PWM modes. In all other modes, the Auto-Reload registers have no function. 0: Read/Write Capture/Compare Registers at PCA0CPHn and PCA0CPLn. 1: Read/Write Auto-Reload Registers at PCA0CPHn and PCA0CPLn. 6 ECOV Cycle Overflow Interrupt Enable. This bit sets the masking of the Cycle Overflow Flag (COVF) interrupt. 0: COVF will not generate PCA interrupts. 1: A PCA interrupt will be generated when COVF is set. 5 COVF Cycle Overflow Flag. This bit indicates an overflow of the 8th, 9th, 10th, or 11th bit of the main PCA counter (PCA0). The specific bit used for this flag depends on the setting of the Cycle Length Select bits. The bit can be set by hardware or software, but must be cleared by software. 0: No overflow has occurred since the last time this bit was cleared. 1: An overflow has occurred since the last time this bit was cleared. 4:2 Unused Read = 000b; Write = don't care. 1:0 CLSEL[1:0] Cycle Length Select. When 16-bit PWM mode is not selected, these bits select the length of the PWM cycle, between 8, 9, 10, or 11 bits. This affects all channels configured for PWM which are not using 16-bit PWM mode. These bits are ignored for individual channels configured to16-bit PWM mode. 00: 8 bits. 01: 9 bits. 10: 10 bits. 11: 11 bits. 348 Rev. 1.0 Si106x/108x SFR Definition 32.4. PCA0CPMn: PCA Capture/Compare Mode Bit 7 6 5 4 3 2 1 0 Name PWM16n ECOMn CAPPn CAPNn MATn TOGn PWMn ECCFn Type R/W R/W R/W R/W R/W R/W R/W R/W Reset 0 0 0 0 0 0 0 0 SFR Address, Page: PCA0CPM0 = 0xDA, 0x0; PCA0CPM1 = 0xDB, 0x0; PCA0CPM2 = 0xDC, 0x0 PCA0CPM3 = 0xDD, 0x0; PCA0CPM4 = 0xDE, 0x0; PCA0CPM5 = 0xCE, 0x0 Bit Name Function 7 PWM16n 16-bit Pulse Width Modulation Enable. This bit enables 16-bit mode when Pulse Width Modulation mode is enabled. 0: 8 to 11-bit PWM selected. 1: 16-bit PWM selected. 6 ECOMn Comparator Function Enable. This bit enables the comparator function for PCA module n when set to 1. 5 CAPPn Capture Positive Function Enable. This bit enables the positive edge capture for PCA module n when set to 1. 4 CAPNn Capture Negative Function Enable. This bit enables the negative edge capture for PCA module n when set to 1. 3 MATn Match Function Enable. This bit enables the match function for PCA module n when set to 1. When enabled, matches of the PCA counter with a module's capture/compare register cause the CCFn bit in PCA0MD register to be set to logic 1. 2 TOGn Toggle Function Enable. This bit enables the toggle function for PCA module n when set to 1. When enabled, matches of the PCA counter with a module's capture/compare register cause the logic level on the CEXn pin to toggle. If the PWMn bit is also set to logic 1, the module operates in Frequency Output Mode. 1 PWMn Pulse Width Modulation Mode Enable. This bit enables the PWM function for PCA module n when set to 1. When enabled, a pulse width modulated signal is output on the CEXn pin. 8 to 11-bit PWM is used if PWM16n is cleared; 16-bit mode is used if PWM16n is set to logic 1. If the TOGn bit is also set, the module operates in Frequency Output Mode. 0 ECCFn Capture/Compare Flag Interrupt Enable. This bit sets the masking of the Capture/Compare Flag (CCFn) interrupt. 0: Disable CCFn interrupts. 1: Enable a Capture/Compare Flag interrupt request when CCFn is set. Note: When the WDTE bit is set to 1, the PCA0CPM5 register cannot be modified, and module 5 acts as the watchdog timer. To change the contents of the PCA0CPM5 register or the function of module 5, the Watchdog Timer must be disabled. Rev. 1.0 349 Si106x/108x SFR Definition 32.5. PCA0L: PCA Counter/Timer Low Byte Bit 7 6 5 4 3 2 1 0 PCA0[7:0] Name Type R/W R/W R/W R/W R/W R/W R/W R/W Reset 0 0 0 0 0 0 0 0 SFR Page = 0x0; SFR Address = 0xF9 Bit Name 7:0 Function PCA0[7:0] PCA Counter/Timer Low Byte. The PCA0L register holds the low byte (LSB) of the 16-bit PCA Counter/Timer. Note: When the WDTE bit is set to 1, the PCA0L register cannot be modified by software. To change the contents of the PCA0L register, the Watchdog Timer must first be disabled. SFR Definition 32.6. PCA0H: PCA Counter/Timer High Byte Bit 7 6 5 4 3 2 1 0 PCA0[15:8] Name Type R/W R/W R/W R/W R/W R/W R/W R/W Reset 0 0 0 0 0 0 0 0 SFR Page = 0x0; SFR Address = 0xFA Bit Name 7:0 Function PCA0[15:8] PCA Counter/Timer High Byte. The PCA0H register holds the high byte (MSB) of the 16-bit PCA Counter/Timer. Reads of this register will read the contents of a "snapshot" register, whose contents are updated only when the contents of PCA0L are read (see Section 32.1). Note: When the WDTE bit is set to 1, the PCA0H register cannot be modified by software. To change the contents of the PCA0H register, the Watchdog Timer must first be disabled. 350 Rev. 1.0 Si106x/108x SFR Definition 32.7. PCA0CPLn: PCA Capture Module Low Byte Bit 7 6 5 4 3 2 1 0 PCA0CPn[7:0] Name Type R/W R/W R/W R/W R/W R/W R/W R/W Reset 0 0 0 0 0 0 0 0 SFR Addresses: PCA0CPL0 = 0xFB, PCA0CPL1 = 0xE9, PCA0CPL2 = 0xEB, PCA0CPL3 = 0xED, PCA0CPL4 = 0xFD, PCA0CPL5 = 0xD2 PCA0CPL0 = 0x0, PCA0CPL1 = 0x0, PCA0CPL2 = 0x0, PCA0CPL3 = 0x0, PCA0CPL4 = 0x0, PCA0CPL5 = 0x0 Name Function SFR Pages: Bit 7:0 PCA0CPn[7:0] PCA Capture Module Low Byte. The PCA0CPLn register holds the low byte (LSB) of the 16-bit capture module n. This register address also allows access to the low byte of the corresponding PCA channel's auto-reload value for 9, 10, or 11-bit PWM mode. The ARSEL bit in register PCA0PWM controls which register is accessed. Note: A write to this register will clear the module's ECOMn bit to a 0. SFR Definition 32.8. PCA0CPHn: PCA Capture Module High Byte Bit 7 6 5 4 3 2 1 0 PCA0CPn[15:8] Name Type R/W R/W R/W R/W R/W R/W R/W R/W Reset 0 0 0 0 0 0 0 0 SFR Addresses: PCA0CPH0 = 0xFC, PCA0CPH1 = 0xEA, PCA0CPH2 = 0xEC, PCA0CPH3 = 0xEE, PCA0CPH4 = 0xFE, PCA0CPH5 = 0xD3 PCA0CPH0 = 0x0, PCA0CPH1 = 0x0, PCA0CPH2 = 0x0, PCA0CPH3 = 0x0, PCA0CPH4 = 0x0, PCA0CPH5 = 0x0 Name Function SFR Pages: Bit 7:0 PCA0CPn[15:8] PCA Capture Module High Byte. The PCA0CPHn register holds the high byte (MSB) of the 16-bit capture module n. This register address also allows access to the high byte of the corresponding PCA channel's auto-reload value for 9, 10, or 11-bit PWM mode. The ARSEL bit in register PCA0PWM controls which register is accessed. Note: A write to this register will set the module's ECOMn bit to a 1. Rev. 1.0 351 Si106x/108x 33. Device Specific Behavior This chapter contains behavioral differences between the silicon revisions of Si106x/108x devices. These differences do not affect the functionality or performance of most systems and are described below. 33.1. Device Identification The Part Number Identifier on the top side of the device package can be used for decoding device information. The first character of the trace code identifies the silicon revision. On Si106x/108x devices, the trace code will be the fifth letter on the second line. Figure 33.1 show how to find the part number on the top side of the device package. This fifth character identifies the device revision. Figure 33.1. Si106x Revision Information Rev. 1.0 352 Si106x/108x 34. C2 Interface Si106x/108x devices include an on-chip Silicon Labs 2-Wire (C2) debug interface to allow flash programming and in-system debugging with the production part installed in the end application. The C2 interface uses a clock signal (C2CK) and a bi-directional C2 data signal (C2D) to transfer information between the device and a host system. See the C2 Interface Specification for details on the C2 protocol. 34.1. C2 Interface Registers The following describes the C2 registers necessary to perform flash programming through the C2 interface. All C2 registers are accessed through the C2 interface as described in the C2 Interface Specification. C2 Register Definition 34.1. C2ADD: C2 Address Bit 7 6 5 4 3 Name C2ADD[7:0] Type R/W Reset Bit 0 0 0 0 Name 0 2 1 0 0 0 0 Function 7:0 C2ADD[7:0] C2 Address. The C2ADD register is accessed via the C2 interface to select the target Data register for C2 Data Read and Data Write commands. 353 Address Description 0x00 Selects the Device ID register for Data Read instructions 0x01 Selects the Revision ID register for Data Read instructions 0x02 Selects the C2 Flash Programming Control register for Data Read/Write instructions 0xB4 Selects the C2 Flash Programming Data register for Data Read/Write instructions Rev. 1.0 Si106x/108x C2 Register Definition 34.2. DEVICEID: C2 Device ID Bit 7 6 5 4 3 Name DEVICEID[7:0] Type R/W Reset 0 0 0 1 0 C2 Address: 0x00 Bit Name 7:0 2 1 0 1 0 0 Function DEVICEID[7:0] Device ID. This read-only register returns the 8-bit device ID: 0x16 (Si106x/108x). C2 Register Definition 34.3. REVID: C2 Revision ID Bit 7 6 5 4 3 Name REVID[7:0] Type R/W Reset Varies Varies Varies Varies C2 Address: 0x01 Bit Name 7:0 Varies 2 1 0 Varies Varies Varies Function REVID[7:0] Revision ID. This read-only register returns the 8-bit revision ID. For example: 0x00 = Revision A. Rev. 1.0 354 Si106x/108x C2 Register Definition 34.4. FPCTL: C2 Flash Programming Control Bit 7 6 5 4 3 Name FPCTL[7:0] Type R/W Reset 0 0 0 0 0 C2 Address: 0x02 Bit Name 7:0 2 1 0 0 0 0 Function FPCTL[7:0] Flash Programming Control Register. This register is used to enable flash programming via the C2 interface. To enable C2 flash programming, the following codes must be written in order: 0x02, 0x01. Note that once C2 flash programming is enabled, a system reset must be issued to resume normal operation. C2 Register Definition 34.5. FPDAT: C2 Flash Programming Data Bit 7 6 5 4 3 Name FPDAT[7:0] Type R/W Reset 0 0 0 0 C2 Address: 0xB4 Bit Name 7:0 0 2 1 0 0 0 0 Function FPDAT[7:0] C2 Flash Programming Data Register. This register is used to pass flash commands, addresses, and data during C2 flash accesses. Valid commands are listed below. 355 Code Command 0x06 Flash Block Read 0x07 Flash Block Write 0x08 Flash Page Erase 0x03 Device Erase Rev. 1.0 Si106x/108x 34.2. C2 Pin Sharing The C2 protocol allows the C2 pins to be shared with user functions so that in-system debugging and flash programming may be performed. This is possible because C2 communication is typically performed when the device is in the halt state, where all on-chip peripherals and user software are stalled. In this halted state, the C2 interface can safely "borrow" the C2CK (RST) and C2D pins. In most applications, external resistors are required to isolate C2 interface traffic from the user application. A typical isolation configuration is shown in Figure 34.1. Si106x/Si108x RST (a) C2CK Input (b) C2D Output (c) C2 Interface Master Figure 34.1. Typical C2 Pin Sharing The configuration in Figure 34.1 assumes the following: 1. The user input (b) cannot change state while the target device is halted. 2. The RST pin on the target device is used as an input only. Additional resistors may be necessary depending on the specific application. Rev. 1.0 356 Si106x/108x DOCUMENT CHANGE LIST Revision 0.1 to Revision 0.5 Updated data sheet to include Si108x family information. Updated block diagram figure 1.1 to include Si108x functionality. Updated application examples for Figures 1.2 and 1.3. Revised package drawing in Figure 3.4 and Table 3.4. Revision 0.5 to Revision 1.0 Updated the XIN and XOUT descriptions in Tables 3.1, 3.2, and 3.3 Updated the notes in Tables 4.11-4.20 to reflect final production parts. Removed the section entitled Definition of Test Conditions. Updated Figure 21.4 to reflect both EZRadio and EZRadioPRO. 357 Rev. 1.0 Smart. Connected. Energy-Friendly Products Quality Support and Community www.silabs.com/products www.silabs.com/quality community.silabs.com Disclaimer Silicon Laboratories intends to provide customers with the latest, accurate, and in-depth documentation of all peripherals and modules available for system and software implementers using or intending to use the Silicon Laboratories products. Characterization data, available modules and peripherals, memory sizes and memory addresses refer to each specific device, and "Typical" parameters provided can and do vary in different applications. Application examples described herein are for illustrative purposes only. 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