HC05
MC68HC05B6/D
Rev. 3
MC68HC05B4
MC68HC705B5
MC68HC05B6
MC68HC05B8
MC68HC05B16
MC68HC705B16
MC68HC05B32
MC68HC705B32
TECHNICAL
DATA
MC68HC05B6 !MOTOROLA
TECHNICAL DATA
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INTRODUCTION
MODES OF OPERATION AND PIN DESCRIPTIONS
MEMORY AND REGISTERS
INPUT/OUTPUT PORTS
PROGRAMMABLE TIMER
SERIAL COMMUNICATIONS INTERFACE
PULSE LENGTH D/A CONVERTERS
ANALOG TO DIGITAL CONVERTER
RESETS AND INTERRUPTS
CPU CORE AND INSTRUCTION SET
ELECTRICAL SPECIFICATIONS
MECHANICAL DATA
ORDERING INFORMATION
APPENDICES
HIGH SPEED OPERATION
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3
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INTRODUCTION
MODES OF OPERATION AND PIN DESCRIPTIONS
MEMORY AND REGISTERS
INPUT/OUTPUT PORTS
PROGRAMMABLE TIMER
SERIAL COMMUNICATIONS INTERFACE
PULSE LENGTH D/A CONVERTERS
ANALOG TO DIGITAL CONVERTER
RESETS AND INTERRUPTS
CPU CORE AND INSTRUCTION SET
ELECTRICAL SPECIFICATIONS
MECHANICAL DATA
ORDERING INFORMATION
MC68HC05B4
HIGH SPEED OPERATION
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All products are sold on Motorola’s Terms & Conditions of Supply. In ordering a product covered by this document the
Customer agrees to be bound by those Terms & Conditions and nothing contained in this document constitutes or forms part
of a contract (with the exception of the contents of this Notice). A copy of Motorola’s Terms & Conditions of Supply is available
on request.
Motorola reserves the right to make changes without further notice to any products herein. Motorola makes no warranty,
representation or guarantee regarding the suitability of its products for any particular purpose, nor does Motorola assume any
liability arising out of the application or use of any product or circuit, and specifically disclaims any and all liability, including
without limitation consequential or incidental damages. “Typical” parameters can and do vary in different applications. All
operating parameters, including “Typicals”, must be validated for each customer application by customer’s technical experts.
Motorola does not convey any license under its patent rights nor the rights of others. Motorola products are not designed,
intended, or authorized for use as components in systems intended for surgical implant into the body, or other applications
intended to support or sustain life, or for any other application in which the failure of the Motorola product could create a
situation where personal injury or death may occur. Should Buyer purchase or use Motorola products for any such unintended
or unauthorized application, Buyer shall indemnify and hold Motorola and its officers, employees, subsidiaries, affiliates, and
distributors harmless against all claims, costs, damages, and expenses, and reasonable attorney fees arising out of, directly
or indirectly, any claim of personal injury or death associated with such unintended or unauthorized use, even if such claim
alleges that Motorola was negligent regarding the design or manufacture of the part. Motorola and !are registered trademarks
of Motorola, Inc. Motorola, Inc. is an Equal Opportunity/Affirmative Action Employer.
The Customer should ensure that it has the most up to date version of the document by contacting its local Motorola office.
This document supersedes any earlier documentation relating to the products referred to herein. The information contained
in this document is current at the date of publication. It may subsequently be updated, revised or withdrawn.
© MOTOROLA LTD., 1995
All Trade Marks recognised. This document contains information on new products. Specifications and information herein are
subject to change without notice.
MC68HC05B6
High-density Complementary
Metal Oxide Semiconductor
(HCMOS) Microcomputer Unit
2
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CAUTION
This document includes descriptions of the various
self-check and bootstrap mechanisms that are
currently implemented as firmware in the non-user
ROM areas of the MC68HC05B6 and related devices.
As these firmware routines are intended primarily to
help Motorola’s engineers test the devices, they may
be changed or removed at any time.
For this reason, Motorola recommends that the
self-check and bootstrap routines are not called from
from the user software. Customers who do call these
routines from the user software do so at their own risk.
MC68HC05B6 MOTOROLA
i
TABLE OF CONTENTS
Paragraph
Number Page
NumberTitle
1
INTRODUCTION
1.1 Features................................................................................................................ 1-2
1.2 Mask options for the MC68HC05B6 ..................................................................... 1-2
2
MODES OF OPERATION AND PIN DESCRIPTIONS
2.1 Modes of operation............................................................................................... 2-1
2.1.1 Single chip mode ............................................................................................ 2-1
2.1.2 Self-check mode............................................................................................. 2-1
2.2 Serial RAM loader ................................................................................................ 2-4
2.3 ‘Jump to any address’........................................................................................... 2-4
2.4 Low power modes................................................................................................. 2-7
2.4.1 STOP .............................................................................................................. 2-7
2.4.2 WAIT............................................................................................................... 2-9
2.4.2.1 Power consumption during WAIT mode.................................................... 2-9
2.4.3 SLOW mode.................................................................................................... 2-10
2.4.3.1 Miscellaneous register ............................................................................. 2-10
2.5 Pin descriptions ................................................................................................... 2-11
2.5.1 VDD and VSS................................................................................................. 2-11
2.5.2 IRQ ................................................................................................................. 2-11
2.5.3 RESET............................................................................................................ 2-11
2.5.4 TCAP1 ............................................................................................................ 2-11
2.5.5 TCAP2 ............................................................................................................ 2-12
2.5.6 TCMP1............................................................................................................ 2-12
2.5.7 TCMP2............................................................................................................ 2-12
2.5.8 OSC1, OSC2 .................................................................................................. 2-12
2.5.8.1 Crystal....................................................................................................... 2-12
2.5.8.2 Ceramic resonator..................................................................................... 2-12
2.5.8.3 External clock............................................................................................ 2-13
2.5.9 RDI (Receive data in)...................................................................................... 2-14
2.5.10 TDO (Transmit data out).................................................................................. 2-14
2.5.11 SCLK............................................................................................................... 2-14
MOTOROLA
ii MC68HC05B6
Table of Contents (continued)
Paragraph
Number Page
NumberTitle
2.5.12 PLMA...............................................................................................................2-14
2.5.13 PLMB...............................................................................................................2-14
2.5.14 VPP1................................................................................................................2-14
2.5.15 VRH.................................................................................................................2-14
2.5.16 VRL..................................................................................................................2-14
2.5.17 PA0 – PA7/PB0 – PB7/PC0 – PC7...................................................................2-14
2.5.18 PD0/AN0–PD7/AN7.........................................................................................2-14
3
MEMORY AND REGISTERS
3.1 Registers ...............................................................................................................3-1
3.2 RAM.......................................................................................................................3-1
3.3 ROM......................................................................................................................3-1
3.4 Self-check ROM ....................................................................................................3-2
3.5 EEPROM...............................................................................................................3-3
3.5.1 EEPROM control register ................................................................................3-3
3.5.2 EEPROM read operation.................................................................................3-5
3.5.3 EEPROM erase operation ...............................................................................3-5
3.5.4 EEPROM programming operation ...................................................................3-6
3.5.5 Options register (OPTR)..................................................................................3-6
3.6 EEPROM during STOP mode ...............................................................................3-7
3.7 EEPROM during WAIT mode................................................................................3-7
3.8 Miscellaneous register .........................................................................................3-9
4
INPUT/OUTPUT PORTS
4.1 Input/output programming .....................................................................................4-1
4.2 Ports A and B ........................................................................................................4-2
4.3 Port C ....................................................................................................................4-3
4.4 Port D ....................................................................................................................4-3
4.5 Port registers.........................................................................................................4-4
4.5.1 Port data registers A and B (PORTA and PORTB)..........................................4-4
4.5.2 Port data register C (PORTC)..........................................................................4-4
4.5.3 Port data register D (PORTD)..........................................................................4-5
4.5.3.1 A/D status/control register..........................................................................4-5
4.5.4 Data direction registers (DDRA, DDRB and DDRC)........................................4-5
4.6 Other port considerations......................................................................................4-6
MC68HC05B6 MOTOROLA
iii
Table of Contents (continued)
Paragraph
Number Page
NumberTitle
5
PROGRAMMABLE TIMER
5.1 Counter................................................................................................................. 5-1
5.1.1 Counter register and alternate counter register ............................................ 5-3
5.2 Timer control and status....................................................................................... 5-4
5.2.1 Timer control register (TCR) ........................................................................... 5-4
5.2.2 Timer status register (TSR)............................................................................. 5-6
5.3 Input capture......................................................................................................... 5-7
5.3.1 Input capture register 1 (ICR1) ....................................................................... 5-7
5.3.2 Input capture register 2 (ICR2) ....................................................................... 5-8
5.4 Output compare.................................................................................................... 5-9
5.4.1 Output compare register 1 (OCR1)................................................................. 5-9
5.4.2 Output compare register 2 (OCR2)................................................................. 5-10
5.4.3 Software force compare.................................................................................. 5-11
5.5 Pulse Length Modulation (PLM) ........................................................................... 5-11
5.5.1 Pulse length modulation registers A and B (PLMA/PLMB) .......................... 5-11
5.6 Timer during STOP mode..................................................................................... 5-12
5.7 Timer during WAIT mode...................................................................................... 5-12
5.8 Timer state diagrams............................................................................................ 5-12
6
SERIAL COMMUNICATIONS INTERFACE
6.1 SCI two-wire system features............................................................................... 6-1
6.2 SCI receiver features............................................................................................ 6-3
6.3 SCI transmitter features........................................................................................ 6-3
6.4 Functional description........................................................................................... 6-3
6.5 Data format........................................................................................................... 6-5
6.6 Receiver wake-up operation................................................................................. 6-5
6.6.1 Idle line wake-up............................................................................................. 6-6
6.6.2 Address mark wake-up ................................................................................... 6-6
6.7 Receive data in (RDI) ........................................................................................... 6-6
6.8 Start bit detection.................................................................................................. 6-6
6.9 Transmit data out (TDO)....................................................................................... 6-8
6.10 SCI synchronous transmission............................................................................. 6-9
6.11 SCI registers......................................................................................................... 6-10
6.11.1 Serial communications data register (SCDR) ............................................... 6-10
6.11.2 Serial communications control register 1 (SCCR1) ...................................... 6-10
6.11.3 Serial communications control register 2 (SCCR2) ........................................ 6-14
6.11.4 Serial communications status register (SCSR) ............................................. 6-16
MOTOROLA
iv MC68HC05B6
Table of Contents (continued)
Paragraph
Number Page
NumberTitle
6.11.5 Baud rate register (BAUD)...............................................................................6-18
6.12 Baud rate selection................................................................................................6-19
6.13 SCI during STOP mode.........................................................................................6-21
6.14 SCI during WAIT mode..........................................................................................6-21
7
PULSE LENGTH D/A CONVERTERS
7.1 Miscellaneous register ..........................................................................................7-3
7.2 PLM clock selection...............................................................................................7-4
7.3 PLM during STOP mode .......................................................................................7-4
7.4 PLM during WAIT mode ........................................................................................7-4
8
ANALOG TO DIGITAL CONVERTER
8.1 A/D converter operation.........................................................................................8-1
8.2 A/D registers..........................................................................................................8-3
8.2.1 Port D data register (PORTD)..........................................................................8-3
8.2.2 A/D result data register (ADDATA)...................................................................8-3
8.2.3 A/D status/control register (ADSTAT)...............................................................8-4
8.3 A/D converter during STOP mode.........................................................................8-5
8.4 A/D converter during WAIT mode..........................................................................8-6
8.5 Port D analog input................................................................................................8-6
9
RESETS AND INTERRUPTS
9.1 Resets ...................................................................................................................9-1
9.1.1 Power-on reset.................................................................................................9-2
9.1.2 Miscellaneous register ...................................................................................9-2
9.1.3 RESET pin.......................................................................................................9-3
9.1.4 Computer operating properly (COP) watchdog reset.......................................9-3
9.1.4.1 COP watchdog during STOP mode ...........................................................9-4
9.1.4.2 COP watchdog during WAIT mode............................................................9-4
9.1.5 Functions affected by reset..............................................................................9-5
9.2 Interrupts ...............................................................................................................9-6
9.2.1 Interrupt priorities.............................................................................................9-6
9.2.2 Nonmaskable software interrupt (SWI)............................................................9-6
9.2.3 Maskable hardware interrupts..........................................................................9-7
MC68HC05B6 MOTOROLA
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Table of Contents (continued)
Paragraph
Number Page
NumberTitle
9.2.3.1 External interrupt (IRQ)............................................................................. 9-7
9.2.3.2 Miscellaneous register ............................................................................. 9-9
9.2.3.3 Timer interrupts......................................................................................... 9-10
9.2.3.4 Serial communications interface (SCI) interrupts...................................... 9-10
9.2.4 Hardware controlled interrupt sequence......................................................... 9-11
10
CPU CORE AND INSTRUCTION SET
10.1 Registers............................................................................................................. 10-1
10.1.1 Accumulator (A) ............................................................................................ 10-2
10.1.2 Index register (X)........................................................................................... 10-2
10.1.3 Program counter (PC)................................................................................... 10-2
10.1.4 Stack pointer (SP)......................................................................................... 10-2
10.1.5 Condition code register (CCR)...................................................................... 10-2
10.2 Instruction set ..................................................................................................... 10-3
10.2.1 Register/memory Instructions....................................................................... 10-4
10.2.2 Branch instructions ....................................................................................... 10-4
10.2.3 Bit manipulation instructions ......................................................................... 10-4
10.2.4 Read/modify/write instructions...................................................................... 10-4
10.2.5 Control instructions ....................................................................................... 10-4
10.2.6 Tables............................................................................................................ 10-4
10.3 Addressing modes.............................................................................................. 10-11
10.3.1 Inherent......................................................................................................... 10-11
10.3.2 Immediate..................................................................................................... 10-11
10.3.3 Direct............................................................................................................. 10-11
10.3.4 Extended....................................................................................................... 10-12
10.3.5 Indexed, no offset.......................................................................................... 10-12
10.3.6 Indexed, 8-bit offset....................................................................................... 10-12
10.3.7 Indexed, 16-bit offset..................................................................................... 10-12
10.3.8 Relative......................................................................................................... 10-13
10.3.9 Bit set/clear................................................................................................... 10-13
10.3.10 Bit test and branch........................................................................................ 10-13
MOTOROLA
vi MC68HC05B6
Table of Contents (continued)
Paragraph
Number Page
NumberTitle
11
ELECTRICAL SPECIFICATIONS
11.1 Maximum ratings ................................................................................................11-1
11.2 Thermal characteristics and power considerations .............................................11-2
11.3 DC electrical characteristics ..............................................................................11-3
11.3.1 IDD trends for 5V operation ...............................................................11-4
11.3.2 IDD trends for 3.3V operation ..............................................................11-7
11.4 A/D converter characteristics ...........................................................................11-9
11.5 Control timing ..............................................................................................11-11
12
MECHANICAL DATA
12.1 MC68HC05B6 pin configurations........................................................................12-1
12.1.1 52-pin plastic leaded chip carrier (PLCC) .....................................................12-1
12.1.2 64-pin quad flat pack (QFP) ..........................................................................12-2
12.1.3 56-pin shrink dual in line package (SDIP) ....................................................12-3
12.2 MC68HC05B6 mechanical dimensions...............................................................12-4
12.2.1 52-pin plastic leaded chip carrier (PLCC) .....................................................12-4
12.2.2 64-pin quad flat pack (QFP) .........................................................................12-5
12.2.3 56-pin shrink dual in line package (SDIP)......................................................12-6
13
ORDERING INFORMATION
13.1 EPROMS.............................................................................................................13-2
13.2 Verification media................................................................................................13-2
13.3 ROM verification units (RVU)...............................................................................13-2
MC68HC05B6 MOTOROLA
vii
Table of Contents (continued)
Paragraph
Number Page
NumberTitle
A
MC68HC05B4
B
MC68HC05B8
C
MC68HC705B5
C.1 EPROM.................................................................................................................C-5
C.1.1 EPROM programming operation.....................................................................C-5
C.2 EPROM registers..................................................................................................C-6
C.2.1 EPROM control register ...............................................................................C-6
C.3 Options register (OPTR) ......................................................................................C-7
C.4 Bootstrap mode ....................................................................................................C-8
C.4.1 Erased EPROM verification ............................................................................C-11
C.4.2 EPROM parallel bootstrap load.......................................................................C-11
C.4.3 EPROM (RAM) serial bootstrap load and execute..........................................C-13
C.4.4 RAM parallel bootstrap load and execute .......................................................C-14
C.4.5 Bootstrap loader timing diagrams ............................................................C-17
C.5 DC electrical characteristics .................................................................................C-19
C.6 Control timing........................................................................................................C-19
D
MC68HC05B16
D.1 Self-check routines..............................................................................................D-1
E
MC68HC705B16
E.1 EPROM.................................................................................................................E-5
E.1.1 EPROM read operation...................................................................................E-5
E.1.2 EPROM program operation.............................................................................E-5
E.1.3 EPROM/EEPROM/ECLK control register .....................................................E-6
E.1.4 Mask option register ......................................................................................E-8
E.1.5 EEPROM options register (OPTR) ................................................................E-9
E.2 Bootstrap mode ....................................................................................................E-10
E.2.1 Erased EPROM verification ............................................................................E-13
MOTOROLA
viii MC68HC05B6
Table of Contents (continued)
Paragraph
Number Page
NumberTitle
E.2.2 EPROM/EEPROM parallel bootstrap.............................................................. E-13
E.2.3 EEPROM/EPROM/RAM serial bootstrap........................................................ E-16
E.2.4 RAM parallel bootstrap ................................................................................... E-19
E.2.4.1 Jump to start of RAM ($0050)................................................................... E-20
E.2.5 Maximum ratings ............................................................................................ E-21
E.2.6 Thermal characteristics and power considerations......................................... E-22
E.2.7 DC electrical characteristics .......................................................................E-23
E.2.8 A/D converter characteristics .....................................................................E-26
E.3 Control timing ................................................................................................E-28
F
MC68HC05B32
G
MC68HC705B32
G.1 EPROM ................................................................................................................G-5
G.1.1 EPROM read operation...................................................................................G-5
G.1.2 EPROM program operation ............................................................................G-5
G.1.3 EPROM/EEPROM control register ...............................................................G-6
G.1.4 Mask option register .....................................................................................G-8
G.1.5 Options register (OPTR) ...............................................................................G-9
G.2 Bootstrap mode....................................................................................................G-10
G.2.1 Erased EPROM verification............................................................................G-13
G.2.2 EPROM/EEPROM parallel bootstrap..............................................................G-13
G.2.3 Serial RAM loader...........................................................................................G-16
G.2.3.1 Jump to start of RAM ($0051)...................................................................G-16
G.2.4 Maximum ratings ............................................................................................G-19
G.2.5 Thermal characteristics and power considerations.........................................G-20
G.2.6 DC electrical characteristics ......................................................................G-21
G.2.7 A/D converter characteristics ....................................................................G-24
G.2.8 Control timing ..........................................................................................G-26
H
HIGH SPEED OPERATION
H.1 DC electrical characteristics ...............................................................................H-2
H.2 A/D converter characteristics ..............................................................................H-3
H.3 Control timing for 5V operation .......................................................................H-4
MC68HC05B6 MOTOROLA
ix
LIST OF FIGURES
Figure
Number Page
NumberTitle
1-1 MC68HC05B6 block diagram.................................................................................1-3
2-1 MC68HC05B6 self-check schematic diagram........................................................2-3
2-2 MC68HC05B6 ‘load program in RAM and execute’ schematic diagram ................2-5
2-3 MC68HC05B6 ‘jump to any address’ schematic diagram ......................................2-6
2-4 STOP and WAIT flowcharts....................................................................................2-8
2-5 Slow mode divider block diagram...........................................................................2-10
2-6 Oscillator connections ............................................................................................2-13
3-1 Memory map of the MC68HC05B6 ........................................................................3-2
4-1 Standard I/O port structure.....................................................................................4-2
4-2 ECLK timing diagram..............................................................................................4-3
4-3 Port logic levels.......................................................................................................4-6
5-1 16-bit programmable timer block diagram ..............................................................5-2
5-2 Timer state timing diagram for reset.......................................................................5-13
5-3 Timer state timing diagram for input capture..........................................................5-13
5-4 Timer state timing diagram for output compare......................................................5-14
5-5 Timer state timing diagram for timer overflow.........................................................5-14
6-1 Serial communications interface block diagram......................................................6-2
6-2 SCI rate generator division.....................................................................................6-4
6-3 Data format.............................................................................................................6-5
6-4 SCI examples of start bit sampling technique ........................................................6-7
6-5 SCI sampling technique used on all bits.................................................................6-7
6-6 Artificial start following a framing error ...................................................................6-8
6-7 SCI start bit following a break.................................................................................6-8
6-8 SCI example of synchronous and asynchronous transmission..............................6-9
6-9 SCI data clock timing diagram (M=0) .....................................................................6-12
6-10 SCI data clock timing diagram (M=1) .....................................................................6-13
7-1 PLM system block diagram.....................................................................................7-1
7-2 PLM output waveform examples.............................................................................7-2
7-3 PLM clock selection................................................................................................7-4
8-1 A/D converter block diagram ..................................................................................8-2
8-2 Electrical model of an A/D input pin........................................................................8-6
9-1 Reset timing diagram..............................................................................................9-1
9-2 Watchdog system block diagram............................................................................9-3
9-3 Interrupt flow chart..................................................................................................9-8
MOTOROLA
xMC68HC05B6
LIST OF FIGURES (continued)
Figure
Number Page
NumberTitle
10-1 Programming model.............................................................................................10-1
10-2 Stacking order......................................................................................................10-1
11-1 Equivalent test load..............................................................................................11-2
11-2 Run IDD vs internal operating frequency (4.5V, 5.5V)..........................................11-4
11-3 Run IDD (SM = 1) vs internal operating frequency (4.5V, 5.5V)...........................11-4
11-4 Wait IDD vs internal operating frequency (4.5V, 5.5V)..........................................11-4
11-5 Wait IDD (SM = 1) vs internal operating frequency (4.5V, 5.5V)...........................11-5
11-6 Increase in IDD vs frequency for A/D, SCI systems active, VDD = 5.5V...............11-5
11-7 IDD vs mode vs internal operating frequency, VDD = 5.5V ...................................11-5
11-8 Run IDD vs internal operating frequency (3V, 3.6V).............................................11-7
11-9 Run IDD (SM = 1) vs internal operating frequency (3V,3.6V)...............................11-7
11-10 Wait IDD vs internal operating frequency (3V, 3.6V).............................................11-7
11-11 Wait IDD (SM = 1) vs internal operating frequency (3V, 3.6V)..............................11-8
11-12 Increase in IDD vs frequency for A/D, SCI systems active, VDD = 3.6V................11-8
11-13 IDD vs mode vs internal operating frequency, VDD = 3.6V ...................................11-8
11-14 Timer relationship.................................................................................................11-13
12-1 52-pin PLCC pinout..............................................................................................12-1
12-2 64-pin QFP pinout................................................................................................12-2
12-3 56-pin SDIP pinout...............................................................................................12-3
12-4 52-pin PLCC mechanical dimensions ..................................................................12-4
12-5 64-pin QFP mechanical dimensions.....................................................................12-5
12-6 56-pin SDIP mechanical dimensions....................................................................12-6
A-1 MC68HC05B4 block diagram.................................................................................A-2
A-2 Memory map of the MC68HC05B4........................................................................A-3
B-1 MC68HC05B8 block diagram.................................................................................B-2
B-2 Memory map of the MC68HC05B8........................................................................B-3
C-1 MC68HC705B5 block diagram.............................................................................. C-2
C-2 Memory map of the MC68HC705B5..................................................................... C-3
C-3 Modes of operation flow chart (1 of 2)................................................................... C-9
C-4 Modes of operation flow chart (2 of 2)................................................................... C-10
C-5 Timing diagram with handshake............................................................................ C-11
C-6 EPROM(RAM) parallel bootstrap schematic diagram........................................... C-12
C-7 EPROM (RAM) serial bootstrap schematic diagram............................................. C-15
C-8 RAM parallel bootstrap schematic diagram........................................................... C-16
C-9 EPROM parallel bootstrap loader timing diagram................................................. C-17
C-10 RAM parallel loader timing diagram..................................................................... C-18
D-1 MC68HC05B16 block diagram.............................................................................. D-2
D-2 Memory map of the MC68HC05B16..................................................................... D-3
E-1 MC68HC705B16 block diagram.............................................................................E-2
E-2 Memory map of the MC68HC705B16....................................................................E-3
MC68HC05B6 MOTOROLA
xi
LIST OF FIGURES (continued)
Figure
Number Page
NumberTitle
E-3 Modes of operation flow chart (1 of 2)................................................................... E-11
E-4 Modes of operation flow chart (2 of 2)................................................................... E-12
E-5 Timing diagram with handshake............................................................................ E-13
E-6 Parallel EPROM loader timing diagram................................................................. E-14
E-7 EPROM Parallel bootstrap schematic diagram...................................................... E-15
E-8 RAM/EPROM/EEPROM serial bootstrap schematic diagram............................... E-17
E-9 Parallel RAM loader timing diagram...................................................................... E-19
E-10 RAM parallel bootstrap schematic diagram........................................................... E-20
E-11 Equivalent test load............................................................................................... E-22
E-12 Timer relationship.................................................................................................. E-30
F-1 MC68HC05B32 block diagram...............................................................................F-2
F-2 Memory map of the MC68HC05B32 ......................................................................F-3
G-1 MC68HC705B32 block diagram............................................................................G-2
G-2 Memory map of the MC68HC705B32 ...................................................................G-3
G-3 Modes of operation flow chart (1 of 2)...................................................................G-11
G-4 Modes of operation flow chart (2 of 2)...................................................................G-12
G-5 Timing diagram with handshake............................................................................G-14
G-6 Parallel EPROM loader timing diagram.................................................................G-14
G-7 EPROM parallel bootstrap schematic diagram......................................................G-15
G-8 RAM load and execute schematic diagram ...........................................................G-17
G-9 Parallel RAM loader timing diagram......................................................................G-18
G-10 Equivalent test load ...............................................................................................G-20
G-11 Timer relationship..................................................................................................G-28
H-1 Timer relationship..................................................................................................H-4
THIS PAGE INTENTIONALLY LEFT BLANK
MOTOROLA
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MC68HC05B6 MOTOROLA
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LIST OF TABLES
Table
Number Page
NumberTitle
1-1 Data sheet appendices...........................................................................................1-1
2-1 Mode of operation selection ...................................................................................2-1
2-2 MC68HC05B6 self-check results............................................................................2-2
3-1 EEPROM control bits description ...........................................................................3-4
3-2 Register outline.......................................................................................................3-8
3-3 IRQ sensitivity.........................................................................................................3-9
4-1 I/O pin states ..........................................................................................................4-2
6-1 Method of receiver wake-up ...................................................................................6-11
6-2 SCI clock on SCLK pin ...........................................................................................6-13
6-3 First prescaler stage...............................................................................................6-18
6-4 Second prescaler stage (transmitter) .....................................................................6-18
6-5 Second prescaler stage (receiver)..........................................................................6-19
6-6 SCI baud rate selection..........................................................................................6-20
8-1 A/D clock selection .................................................................................................8-4
8-2 A/D channel assignment.........................................................................................8-5
9-1 Effect of RESET, POR, STOP and WAIT................................................................9-5
9-2 Interrupt priorities ...................................................................................................9-7
9-3 IRQ sensitivity.........................................................................................................9-9
10-1 MUL instruction.....................................................................................................10-5
10-2 Register/memory instructions...............................................................................10-5
10-3 Branch instructions...............................................................................................10-6
10-4 Bit manipulation instructions.................................................................................10-6
10-5 Read/modify/write instructions .............................................................................10-7
10-6 Control instructions...............................................................................................10-7
10-7 Instruction set (1 of 2)...........................................................................................10-8
10-8 Instruction set (2 of 2)...........................................................................................10-9
10-9 M68HC05 opcode map.........................................................................................10-10
11-1 Maximum ratings ..................................................................................................11-1
11-2 Package thermal characteristics...........................................................................11-2
11-3 DC electrical characteristics for 5V operation.......................................................11-3
11-4 DC electrical characteristics for 3.3V operation....................................................11-6
11-5 A/D characteristics for 5V operation.....................................................................11-9
11-6 A/D characteristics for 3.3V operation..................................................................11-10
11-7 Control timing for 5V operation.............................................................................11-11
11-8 Control timing for 3.3V operation..........................................................................11-12
MOTOROLA
xiv MC68HC05B6
LIST OF TABLES (continued)
Table
Number Page
NumberTitle
13-1 MC order numbers ...............................................................................................13-1
13-2 EPROMs for pattern generation...........................................................................13-2
A-1 Register outline ......................................................................................................A-4
B-1 Register outline ......................................................................................................B-4
C-1 Register outline ..................................................................................................... C-4
C-2 Mode of operation selection.................................................................................. C-8
C-3 Bootstrap vector targets in RAM............................................................................ C-14
C-4 Additional DC electrical characteristics for MC68HC705B5.................................. C-19
C-5 Additional control timing for MC68HC705B5......................................................... C-19
D-1 Register outline ..................................................................................................... D-4
E-1 Register outline ......................................................................................................E-4
E-2 EPROM control bits description .............................................................................E-6
E-3 EEPROM control bits description...........................................................................E-7
E-4 Mode of operation selection...................................................................................E-10
E-5 Bootstrap vector targets in RAM.............................................................................E-18
E-6 Maximum ratings....................................................................................................E-21
E-7 Package thermal characteristics.............................................................................E-22
E-8 DC electrical characteristics for 5V operation ........................................................E-23
E-9 DC electrical characteristics for 3.3V operation .....................................................E-25
E-10 A/D characteristics for 5V operation.......................................................................E-26
E-11 A/D characteristics for 3.3V operation....................................................................E-27
E-12 Control timing for 5V operation...............................................................................E-28
E-13 Control timing for 3.3V operation............................................................................E-29
F-1 Register outline ......................................................................................................F-4
G-1 Register outline .....................................................................................................G-4
G-2 EPROM control bits description ............................................................................G-6
G-3 EEPROM control bits description..........................................................................G-7
G-4 Mode of operation selection..................................................................................G-10
G-5 Bootstrap vector targets in RAM............................................................................G-16
G-6 Maximum ratings...................................................................................................G-19
G-7 Package thermal characteristics............................................................................G-20
G-8 DC electrical characteristics for 5V operation .......................................................G-21
G-9 DC electrical characteristics for 3.3V operation ....................................................G-23
G-10 A/D characteristics for 5V operation......................................................................G-24
G-11 A/D characteristics for 3.3V operation...................................................................G-25
G-12 Control timing for 5V operation..............................................................................G-26
G-13 Control timing for operation at 3.3V.......................................................................G-27
H-1 Ordering information.............................................................................................. H-1
H-2 DC electrical characteristics for 5V operation ....................................................... H-2
H-3 A/D characteristics for 5V operation...................................................................... H-3
MC68HC05B6 MOTOROLA
1-1
INTRODUCTION
1
1
INTRODUCTION
The MC68HC05B6 microcomputer (MCU) is a member of Motorola’s MC68HC05 family of
low-cost single chip microcomputers. This 8-bit MCU contains an on-chip oscillator, CPU, RAM,
ROM, EEPROM, A/D converter, pulse length modulated outputs, I/O, serial communications
interface, programmable timer system and watchdog. The fully static design allows operation at
frequencies down to dc to further reduce the already low power consumption to a f ew micro-amps.
This data sheet is structured such that devices similar to the MC68HC05B6 are described in a set
of appendices (see Table 1-1).
Table 1-1 Data sheet appendices
Device Appendix Differences from MC68HC05B6
MC68HC05B4 A 4K bytes ROM; no EEPROM
MC68HC05B8 B 7.25K bytes ROM
MC68HC705B5 C 6K bytes EPROM; self-check replaced by bootstrap
firmware; no EEPROM
MC68HC05B16 D 16K bytes ROM; increased RAM and self-check ROM
MC68HC705B16 E 16K bytes EPROM; increased RAM; self-check replaced
by bootstrap firmware; modified power-on reset routine
MC68HC05B32 F 32K bytes ROM; no page zero ROM; increased RAM
MC68HC705B32 G 32K bytes EPROM; no page zero ROM; increased RAM;
self-check mode replaced by bootstrap firmware
MOTOROLA
1-2 MC68HC05B6INTRODUCTION
1
1.1 Features
Hardware features
• Fully static design featuring the industry standard M68HC05 family CPU core
• On chip crystal oscillator with divide by 2 or a software selectable divide by 32 option (SLOW
mode)
• 2.1 MHz internal operating frequency at 5V; 1.0 MHz at 3V
• 176 bytes of RAM
• 5936 bytes of user ROM plus 14 bytes of user vectors
• 256 bytes of byte erasable EEPROM with internal charge pump and security bit
• Write/erase protect bit for 224 of the 256 bytes EEPROM
• Self test/bootstrap mode
• Power saving STOP, WAIT and SLOW modes
• Three 8-bit parallel I/O ports and one 8-bit input-only port
• Software option available to output the internal E-clock to port pin PC2
• 16-bit timer with 2 input captures and 2 output compares
• Computer operating properly (COP) watchdog timer
• Serial communications interface system (SCI) with independent transmitter/receiver baud rate
selection; receiver wake-up function for use in multi-receiver systems
• 8 channel A/D converter
• 2 pulse length modulation systems which can be used as D/A converters
• One interrupt request input plus 4 on-board hardware interrupt sources
• Available in 52-pin plastic leaded chip carrier (PLCC), 64-pin quad flat pack (QFP) and 56-pin
shrink dual in line (SDIP) packages
•Complete development system support available using the MMDS05 development station with
the M68HC05BEM emulation module or the M68HC05BEVS evaluation system
1.2 Mask options for the MC68HC05B6
The MC68HC05B6 has three mask options that are programmed during manufacture and must
be specified on the order form.
• Power-on-reset delay (tPORL) = 16 or 4064 cycles
MC68HC05B6 MOTOROLA
1-3
INTRODUCTION
1
• Automatic watchdog enable/disable following a power-on or external reset
• Watchdog enable/disable during WAIT mode
Warning: It is recommended that an external clock is always used if tPORL is set to 16 cycles. This
will prevent any problems arising with oscillator stability when the device is put into
STOP mode.
Figure 1-1 MC68HC05B6 block diagram
Port A
PA0
PA1
PA2
PA3
PA4
PA5
PA6
PA7
Port B
PB0
PB1
PB2
PB3
PB4
PB5
PB6
PB7
Port C
PC0
PC1
PC2/ECLK
PC3
PC4
PC5
PC6
PC7
16-bit
programmable
timer
Port D
PD0/AN0
PD1/AN1
PD2/AN2
PD3/AN3
PD4/AN4
PD5/AN5
PD6/AN6
PD7/AN7
Oscillator
176 bytes
RAM
COP watchdog
RESET
IRQ
VDD
VSS
OSC1
OSC2
M68HC05
CPU
SCI
A/D converter
PLM
TCAP1
TCAP2
TCMP1
TCMP2
VRH
VRL
RDI
SCLK
TDO
VPP1
256 bytes
EEPROM
Charge pump
2 / 32
PLMA D/A
PLMB D/A
8-bit
432 bytes
User ROM
5950 bytes
self check ROM
(including 14 bytes
User vectors)
MOTOROLA
1-4 MC68HC05B6INTRODUCTION
THIS PAGE INTENTIONALLY LEFT BLANK
1
MC68HC05B6 MOTOROLA
2-1
MODES OF OPERATION AND PIN DESCRIPTIONS
2
2
MODES OF OPERATION AND PIN
DESCRIPTIONS
2.1 Modes of operation
The MC68HC05B6 MCU has two modes of operation, namely single chip and self check modes.
Table 2-1 shows the conditions required to enter each mode on the rising edge of
RESET.
2.1.1 Single chip mode
This is the normal operating mode of the MC68HC05B6. In this mode the device functions as a
self-contained microcomputer (MCU) with all on-board peripherals, including the three 8-bit I/O
ports and the 8-bit input-only port, available to the user. All address and data activity occurs within
the MCU.
2.1.2 Self-check mode
The self-check function available on the MC68HC05B6 provides an internal capability to
determine if the device is functional. Self-check is perf ormed using the circuit shown in Figure 2-1.
Port C pins PC0–PC3 are monitored for the self-chec k results (light emitting diodes are shown but
other devices could be used), and are interpreted as described in Table 2-2. The self-check mode
Table 2-1 Mode of operation selection
IRQ pin TCAP1 pin PD3 PD4 Mode
VSS to VDD VSS to VDD X X Single chip
2VDD VDD 0 X Self-check
2VDD VDD 1 0 Serial RAM loader
2VDD VDD 1 1 Jump to any address
MOTOROLA
2-2 MC68HC05B6MODES OF OPERATION AND PIN DESCRIPTIONS
2
is entered by applying 2 x VDD dc (via a 4.7k resistor) to the IRQ pin and 5V dc input (via a 4.7k
resistor) to the TCAP1 pin and then depressing the reset s witch to execute a reset. After reset, the
following tests are performed automatically and once completed they continually repeat. A good
device will exhibit flashing LEDs; a bad device will be indicated b y the LEDs holding at one v alue.
I/0 — Functionally exercises ports A, B, C and D
RAM — Counter test for each RAM byte
ROM — Exclusive OR with odd ones parity result
Timer — Tracks counter registers and checks ICF1, ICF2, OCF1,
OCF2 and TOF flags
SCI — Transmission test; check for RDRF, TDRE, TC and FE
flags
A/D — Check A/D functionality on internal channels: VRL, VRH
and (VRL + VRH)/2
EEPROM — This test is optional; it executes a write/erase test of the
256 bytes EEPROM (available only for the MC68HC05B6
version), and then deactivates the security bit.
PLM — Checks the PLM basic functionality
Interrupts — Tests external timer and SCI interrupts
Watchdog — Tests the watchdog
Table 2-2 MC68HC05B6 self-check results
PC3 PC2 PC1 PC0 Remarks
1 0 0 1 Bad port
0 1 1 0 Bad port
1 0 1 0 Bad RAM
1 0 1 1 Bad ROM
1 1 0 0 Bad Timer
1 1 0 1 Bad SCI
1 1 1 0 Bad A/D
0 0 0 0 Bad EEPROM (or other if B4)
0 0 0 1 Bad PLM
0 0 1 0 Bad interrupts
0 0 1 1 Bad watchdog
Flashing Good device
All others Bad device, bad port etc.
‘0’ indicates LED on; ‘1’ indicates LED off
MC68HC05B6 MOTOROLA
2-3
MODES OF OPERATION AND PIN DESCRIPTIONS
2
Figure 2-1 MC68HC05B6 self-check schematic diagram
6
40
51
OSC1
OSC2
IRQ
TCAP2
TCMP2
TCAP1
PB7
PB6
PB5
PB4
PB3
PB2
PB1
PB0
PC7
PC6
PC5
PC4
PC3
PC2
PC1
PC0
VRLVSS
PD7
PD6
PD5
PD4
PD3
PD2
PD1
PD0
PA7
PA6
PA5
PA4
PA3
PA2
PA1
PA0
TCMP1
SCLK
PLMB
PLMA
TDO
RDI
VPP1
NC
RESET
NC VRH VDD
18
50
52
20
21
2
3
4
5
9
11
12
13
14
24
25
26
27
28
29
30
31
16
17
19
23
1
22
32
33
34
35
36
37
38
39
42
43
44
45
46
47
48
49
41 7
0.01 F
10 nF 47 F
10 M
4 MHz
22 pF 4k7 
4k7 
680 
22 pF
4k7 
4k7 
680 
680 
680 
BC239
P1 GND
+5V
2xVDD
RESET
EEPROM tested
EEPROM not tested
15 8 10
Note:
For the MC68HC05B4, switches on PB5 and PB6 have no effect
All resistors are 10 k, unless otherwise stated.
MC68HC05B6 (52-pin package)
MOTOROLA
2-4 MC68HC05B6MODES OF OPERATION AND PIN DESCRIPTIONS
2
2.2 Serial RAM loader
The ‘load program in RAM and execute’ mode is entered if the following conditions are satisfied
when the reset pin is released to VDD. The format used is identical to the format used for the
MC68HC805C4. The SEC bit in the options register must be inactive, i.e. set to ‘1’.
–IRQ at 2xVDD
– TCAP1 at VDD
– PD3 at VDD for at least 30 machine cycles after reset
– PD4 at VSS for at least 30 machine cycles after reset
In the ‘load program in RAM and execute’ routine, user programs are loaded into MCU RAM via
the SCI port and then e xecuted. Data is loaded sequentially, starting at RAM location $0050, until
the last byte is loaded. Prog ram control is then transferred to the RAM program starting at location
$0051. The first byte loaded is the count of the total n umber of bytes in the program plus the count
byte. The program starts at the second byte in RAM. During the firmware initialization stage, the
SCI is configured f or the NRZ data format (idle line, start bit, eight data bits and stop bit). The baud
rate is 9600 with a 4 MHz crystal. A program to convert ASCII S-records to the format required by
the RAM loader is available from Motorola.
If immediate execution is not desired after loading the RAM program, it is possible to hold off
execution. This is accomplished b y setting the byte count to a v alue that is greater than the o verall
length of the loaded data. When the last byte is loaded, the firmware will halt operation expecting
additional data to arrive. At this point, the reset switch is placed in the reset position which will
reset the MCU, but keep the RAM program intact. All routines can now be entered from this state ,
including the one which will execute the program in RAM (see Section 2.3).
To load a program in the EEPROM, the ‘load program in RAM and execute’ function is also used.
In this instance the process involves two distinct steps. Firstly, the RAM is loaded with a program
which will control the loading of the EEPROM, and when the RAM contents are executed, the
MCU is instructed to load the EEPROM.
The erased state of the EEPROM is $FF.
Figure 2-2 shows the schematic diagram of the circuit required for the serial RAM loader.
2.3 ‘Jump to any address’
The ‘jump to any address’ mode is entered when the reset pin is released to VDD, if the following
conditions are satisfied:
–IRQ at 2xVDD
– TCAP1 at VDD
– PD3 at VDD for at least 30 machine cycles after reset
– PD4 at VDD for at least 30 machine cycles after reset
MC68HC05B6 MOTOROLA
2-5
MODES OF OPERATION AND PIN DESCRIPTIONS
2
This function allows execution of programs previously loaded in RAM or EEPROM using the
methods outlined in Section 2.2.
To execute the ‘jump to any address’ function, data input at port A has to be $CC and data input at
port B and por t C should represent the MSB and LSB respectively, of the address to jump to for
execution of the user program. A schematic diagram of the circuit required is shown inFigure 2-3.
Figure 2-2 MC68HC05B6 ‘load program in RAM and e xecute’ schematic diagram
32
OSC1
OSC2
IRQ
TCAP2
TCMP2
TCAP1
PB7
PB6
PB5
PB4
PB3
PB2
PB1
PB0
PC7
PC6
PC5
PC4
PC3
PC2
PC1
PC0
VSS
PD7
PD6
PD5
PD4
PD3
PD2
PD1
PD0
PA7
PA6
PA5
PA4
PA3
PA2
PA1
PA0
RESET
VDD
18
24
25
26
27
28
29
30
31
16
17
19
41
10 k
0.01 F
10 nF 47 F
10 M
4 MHz
22 pF
10 k
22 pF
P1 GND
+5V
2xVDD
RESET 10
VRH
VRL
VPP1
PLMA
PLMB
TCMP1
RDI
TDO
NC
NC
RS232 level translator
suggested:
MC145406 or MAX232
9600 Bd
RS232
SCLK
10 k
10 k
10 k
11
9
22
8
7
40
20
21
51
1
23
2
3
4
5
12
13
14
33
34
35
36
37
38
39
42
43
44
45
46
47
48
49
6
15
50
52
optional
3 x 10 k
Connect as required
for the application
Connect as required
for the application
MC68HC05B6 (52-pin package)
MOTOROLA
2-6 MC68HC05B6MODES OF OPERATION AND PIN DESCRIPTIONS
2
Figure 2-3 MC68HC05B6 ‘jump to any address’ schematic diagram
32
OSC1
OSC2
IRQ
TCAP2
TCMP2
TCAP1
PB7
PB6
PB5
PB4
PB3
PB2
PB1
PB0
PC7
PC6
PC5
PC4
PC3
PC2
PC1
PC0
VSS
PD7
PD6
PD5
PD4
PD3
PD2
PD1
PD0
PA7
PA6
PA5
PA4
PA3
PA2
PA1
PA0
RESET
VDD
18
24
25
26
27
28
29
30
31
16
17
19
41
10 k
0.01 F
10 nF 47 F
10 M
4 MHz
22 pF
10 k
22 pF
P1 GND
+5V
2xVDD
RESET 10
VRH
VRL
VPP1
PLMA
PLMB
TCMP1
RDI
TDO
NC
NC
SCLK
10 k
10 k
10 k
11
9
22
8
7
40
20
21
51
1
23
2
3
4
5
12
13
14
33
34
35
36
37
38
39
42
43
44
45
46
47
48
49
6
15
50
52
optional
3 x 10 k
Connect as required
for the application
8 x 10 k optional (see note)
8 x 10 k
8 x 10 k
MSBLSB
Select required address
Note:
These eight resistors are optional; direct connection is possible if pins PA0-PA7, PB0-PB7 and PC0-PC7 are
kept in input mode during application.
MC68HC05B6 (52-pin package)
MC68HC05B6 MOTOROLA
2-7
MODES OF OPERATION AND PIN DESCRIPTIONS
2
2.4 Low power modes
The STOP and WAIT instructions have different effects on the programmable timer, the serial
communications interface, the watchdog system, the EEPROM and the A/D converter. These
different effects are described in the following sections.
2.4.1 STOP
The STOP instruction places the MCU in its lowest power consumption mode. In ST OP mode, the
internal oscillator is turned off, halting all internal processing including timer, serial
communications interface and the A/D converter (see flowchart in Figure 2-4). The only way for
the MCU to wake-up from the STOP mode is b y receipt of an e xternal interrupt or by the detection
of a reset (logic low on RESET pin or a power-on reset).
During STOP mode, the I-bit in the CCR is cleared to enable external interrupts (see Section
10.1.5). The SM bit is cleared to allow nominal speed operation for the 4064 cycles count while
exiting STOP mode (see Section 2.4.3).
All other registers and memory remain unaltered and all input/output lines remain unchanged.
This continues until an external interrupt (IRQ) or reset is sensed, at which time the internal
oscillator is turned on. The external interrupt or reset causes the program counter to vector to the
corresponding locations ($1FFA, B and $1FFE, F respectively).
When leaving STOP mode, a tPORL internal cycles delay is provided to give the oscillator time to
stabilise before releasing CPU operation. This delay is selectable via a mask option to be either
16 or 4064 cycles. The CPU will resume operation by servicing the interr upt that wakes it up, or
by fetching the reset vector, if reset wakes it up.
Warning: If tPORL is selected to be 16 cycles, it is recommended that an external clock signal is
used to avoid problems with oscillator stability while the device is in STOP mode.
Note:
The stacking corresponding to an eventual interrupt to go out of STOP mode will only
be executed when going out of STOP mode.
The following list summarizes the effect of STOP mode on the individual modules of the
MC68HC05B6.
– The watchdog timer is reset; refer to Section 9.1.4.1
– The EEPROM acts as read-only memory (ROM); refer to Section 3.6
– All SCI activity stopped; refer to Section 6.13
– The timer stops counting; refer to Section 5.6
– The PLM outputs remain at current level; refer to Section 7.2
– The A/D converter is disabled; refer to Section 8.3
– The I-bit in the CCR is cleared
MOTOROLA
2-8 MC68HC05B6MODES OF OPERATION AND PIN DESCRIPTIONS
2
Figure 2-4 STOP and WAIT flowcharts
Timer interrupt?
IRQ
external
interrupt?
SCI interrupt?
Stop oscillator and all
clocks.
Clear I bit.
STOP WAIT
Reset?
IRQ
external
interrupt?
Generate watchdog
interrupt
Reset?
Watchdog active?
(1) Fetch reset vector or
(2) Service interrupt:
a. stack
b. set I-bit
c. vector to interrupt
routine
(1) Fetch reset vector or
(2) Service interrupt:
a. stack
b. set I-bit
c. vector to interrupt
routine
Turn on oscillator.
Wait for time delay to
stabilise Restart processor clock
YES
NO
YES
YES
YES
YES
YES
YES
NO
NO
NO
NO
NO
NO
Oscillator active. Timer, SCI,
A/D, EEPROM clocks active.
Processor clocks stopped
Clear I-bit
MC68HC05B6 MOTOROLA
2-9
MODES OF OPERATION AND PIN DESCRIPTIONS
2
2.4.2 WAIT
The WAIT instruction places the MCU in a low power consumption mode, but WAIT mode
consumes more power than STOP mode. All CPU action is suspended and the watchdog is
disabled, but the timer, A/D and SCI systems remain activ e and operate as normal (see flowchart
in Figure 2-4). All other memory and registers remain unaltered and all parallel input/output lines
remain unchanged. The programming or er ase mechanism of the EEPROM is also unaff ected, as
well as the charge pump high voltage generator.
During WAIT mode the I-bit in the CCR is cleared to enable all interrupts. The INTE bit in the
miscellaneous register (Section 2.5) is not affected by WAIT mode. When any interrupt or reset is
sensed, the program counter vectors to the locations containing the start address of the interrupt
or reset service routine.
Any IRQ, timer (overflow, input capture or output compare) or SCI interrupt (in addition to a logic
low on the RESET pin) causes the processor to exit WAIT mode.
If a non-reset e xit from WAIT mode is perf ormed (i.e. timer overflow interrupt exit), the state of the
remaining systems will be unchanged.
If a reset exit from WAIT mode is performed the entire system reverts to the disabled reset state.
Note:
The stacking corresponding to an eventual interrupt to leave WAIT mode will only be
executed when leaving WAIT mode.
The following list summarizes the effect of WAIT mode on the modules of the MC68HC05B6.
– The watchdog timer functions according to the mask option selected; refer
to Section 9.1.4.2
– The EEPROM is not affected; refer to Section 3.7
– The SCI is not affected; refer to Section 6.14
– The timer is not affected; refer to Section 5.7
– The PLM is not affected; refer to Section 7.4
– The A/D converter is not affected; refer to Section 8.4
– The I-bit in the CCR is cleared
2.4.2.1 Power consumption during WAIT mode
Power consumption during WAIT mode depends on how many systems are active. The power
consumption will be highest when all the systems (A/D, timer, EEPROM and SCI) are active, and
lowest when the EEPROM erase and programming mechanism, SCI and A/D are disabled. The
timer cannot be disabled in WAIT mode. It is important that before entering WAIT mode, the
programmer sets the relevant control bits for the individual modules to reflect the desired
functionality during WAIT mode.
Power consumption may be further reduced by the use of SLOW mode.
MOTOROLA
2-10 MC68HC05B6MODES OF OPERATION AND PIN DESCRIPTIONS
2
2.4.3 SLOW mode
The SLOW mode function is controlled by the SM bit in the miscellaneous register at location
$000C. It allows the user to insert, under software control, an extra divide-by-16 between the
oscillator and the internal clock driver (see Figure 2-5). This f eature permits a slo w down of all the
internal operations and thus reduces power consumption. The SLOW mode function should not
be enabled while using the A/D converter or while erasing/programming the EEPROM unless the
internal A/D RC oscillator is turned on.
2.4.3.1 Miscellaneous register
SM — Slow mode
1 (set) – The system runs at a bus speed 16 times lower than normal
(fOSC/32). SLOW mode affects all sections of the device, including
SCI, A/D and timer.
0 (clear) – The system runs at normal bus speed (fOSC/2).
The SM bit is cleared by external or power-on reset. The SM bit is automatically cleared when
entering STOP mode.
Note:
The bits shown shaded in the above representation are explained individually in the
relevant sections of this manual. The complete register plus an explanation of each bit
can be found in Section 3.8.
Figure 2-5 Slow mode divider block diagram
Address bit 7 bit 6 bit 5 bit 4 bit 3 bit 2 bit 1 bit 0 State
on reset
Miscellaneous $000C POR INTP INTN INTE SFA SFB SM WDOG ?001 000?
OSC1
pin OSC2
pin
Oscillator fOSC
Control logicSM–bit
fOSC/2
2 16
Main internal clock
fOSC/32
(bit 1, $000C)
MC68HC05B6 MOTOROLA
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MODES OF OPERATION AND PIN DESCRIPTIONS
2
2.5 Pin descriptions
2.5.1 VDD and VSS
Power is supplied to the microcontroller using these tw o pins. VDD is the positive supply and VSS
is ground.
It is in the nature of CMOS designs that v ery fast signal transitions occur on the MCU pins. These
short rise and fall times place very high short-duration current demands on the power supply. To
prevent noise problems, special care must be taken to provide good power supply by-passing at
the MCU. By-pass capacitors should have good high-frequency char acteristics and be as close to
the MCU as possible. Bypassing requirements vary, depending on how heavily the MCU pins are
loaded.
2.5.2 IRQ
This is an input-only pin for external interrupt sources. Interrupt triggering is selected using the
INTP and INTN bits in the miscellaneous register, to be one of four options detailed in Table 9-3.
In addition, the external interrupt facility (IRQ) can be disabled using the INTE bit in the
miscellaneous register (see Section 3.8). It is only possible to change the interrupt option bits in
the miscellaneous register while the I-bit is set. Selecting a different interrupt option will
automatically clear any pending interrupts. Further details of the external interrupt procedure can
be found in Section 9.2.3.1.
The IRQ pin contains an internal Schmitt trigger as part of its input to improve noise immunity.
2.5.3 RESET
This active low I/O pin is used to reset the MCU . Applying a logic zero to this pin f orces the device
to a known start-up state. An external RC-circuit can be connected to this pin to generate a
power-on-reset (POR) if required. In this case, the time constant must be great enough (at least
100ms) to allow the oscillator circuit to stabilise. This input has an internal Schmitt trigger to
improve noise immunity. When a reset condition occurs internally, i.e. from the COP watchdog, the
RESET pin provides an active-low open drain output signal that may be used to reset external
hardware.
2.5.4 TCAP1
The TCAP1 input controls the input capture 1 function of the on-chip programmable timer system.
MOTOROLA
2-12 MC68HC05B6MODES OF OPERATION AND PIN DESCRIPTIONS
2
2.5.5 TCAP2
The TCAP2 input controls the input capture 2 function of the on-chip programmable timer system.
2.5.6 TCMP1
The TCMP1 pin is the output of the output compare 1 function of the timer system.
2.5.7 TCMP2
The TCMP2 pin is the output of the output compare 2 function of the timer system.
2.5.8 OSC1, OSC2
These pins provide control input for an on-chip oscillator circuit. A cr ystal, ceramic resonator or
external clock signal connected to these pins supplies the oscillator clock. The oscillator frequency
(fOSC) is divided by two to give the internal bus frequency (fOP). There is also a software option
which introduces an additional divide by 16 into the oscillator clock, giving an internal bus
frequency of fOSC/32.
2.5.8.1 Crystal
The circuit shown in Figure 2-6(a) is recommended when using either a crystal or a ceramic
resonator. Figure 2-6(d) lists the recommended capacitance and feedback resistance values. The
internal oscillator is designed to interface with an AT-cut parallel-resonant quartz crystal resonator
in the frequency range specified for fOSC (see Section 11.5). Use of an external CMOS oscillator
is recommended when crystals outside the specified ranges are to be used. The crystal and
associated components should be mounted as close as possible to the input pins to minimise
output distortion and star t-up stabilisation time. The manufacturer of the par ticular crystal being
considered should be consulted for specific information.
2.5.8.2 Ceramic resonator
A ceramic resonator may be used instead of a crystal in cost sensitiv e applications . The circuit shown
in Figure 2-6(a) is recommended when using either a crystal or a ceramic resonator. Figure 2-6(d) lists
the recommended capacitance and feedback resistance values. The manufacturer of the particular
ceramic resonator being considered should be consulted f or specific information.
MC68HC05B6 MOTOROLA
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MODES OF OPERATION AND PIN DESCRIPTIONS
2
2.5.8.3 External clock
An external clock should be applied to the OSC1 input, with the OSC2 pin left unconnected, as
shown in Figure 2-6(c). The tOXOV or tILCH specifications (see Section 11.5) do not apply when
using an external clock input. The equivalent specification of the external clock source should be
used in lieu of tOXOV or tILCH.
Figure 2-6 Oscillator connections
Ceramic resonator
2 – 4MHz Unit
RS(typ) 10
C040 pF
C14.3 pF
COSC1 30 pF
COSC2 30 pF
RP1 – 10 M
Q 1250 —
Crystal
2MHz 4MHz Unit
RS(max) 400 75
C05 7 pF
C18 12 nF
COSC1 15 – 40 15 – 30 pF
COSC2 15 – 30 15 – 25 pF
RP10 10 M
Q 30 000 40 000 —
OSC1 OSC2
RP
MCU
COSC2
COSC1
OSC1 OSC2
MCU
NCExternal
clock
OSC1 OSC2
RS
C1
L
C0
(d) Typical crystal and ceramic resonator parameters
(c) External clock source connections
(b) Crystal equivalent circuit
(a) Crystal/ceramic resonator
oscillator connections
MOTOROLA
2-14 MC68HC05B6MODES OF OPERATION AND PIN DESCRIPTIONS
2
2.5.9 RDI (Receive data in)
The RDI pin is the input pin of the SCI receiver.
2.5.10 TDO (Transmit data out)
The TDO pin is the output pin of the SCI transmitter.
2.5.11 SCLK
The SCLK pin is the clock output pin of the SCI transmitter.
2.5.12 PLMA
The PLMA pin is the output of pulse length modulation converter A.
2.5.13 PLMB
The PLMB pin is the output of pulse length modulation converter B.
2.5.14 VPP1
The VPP1 pin is the output of the charge pump for the EEPROM1 array.
2.5.15 VRH
The VRH pin is the positive reference voltage for the A/D converter.
2.5.16 VRL
The VRL pin is the negative reference voltage for the A/D converter.
2.5.17 PA0 – PA7/PB0 – PB7/PC0 – PC7
These 24 I/O lines comprise ports A, B and C. The state of an y pin is software programmable, and
all the pins are configured as inputs during power-on or reset.
Under software control the PC2 pin can output the internal E-clock (see Section 4.2).
2.5.18 PD0/AN0–PD7/AN7
This 8-bit input only port (D) shares its pins with the A/D converter. When enabled, the A/D
converter uses pins PD0/AN0 – PD7/AN7 as its analog inputs. On reset, the A/D converter is
disabled which forces the port D pins to be input only port pins (see Section 8.5).
MC68HC05B6 MOTOROLA
3-1
MEMORY AND REGISTERS
3
3
MEMORY AND REGISTERS
The MC68HC05B6 MCU is capable of addressing 8192 bytes of memor y and registers with its
program counter. The memory map includes 5950 bytes of User ROM (including User vectors),
432 bytes of self check ROM, 176 bytes of RAM and 256 bytes of EEPROM.
3.1 Registers
All the I/O, control and status registers of the MC68HC05B6 are contained within the first 32-byte
block of the memory map, as shown in Figure 3-1. The miscellaneous register is sho wn in Section
3.8 as this register contains bits which are relevant to several modules.
3.2 RAM
The user RAM comprises 176 bytes of memory, from $0050 to $00FF. This is shared with a 64
byte stack area. The stack begins at $00FF and may extend down to $00C0.
Note:
Using the stac k area for data stor age or tempor ary work locations requires care to prevent
the data from being overwritten due to stacking from an interrupt or subroutine call.
3.3 ROM
The User ROM consists of 5950 bytes of ROM mapped as follows:
• 48 bytes of page zero ROM from $0020 to $004F
• 5888 bytes of User ROM from $0800 to $1EFF
• 14 bytes of User vectors from $1FF2 to $1FFF
MOTOROLA
3-2 MC68HC05B6MEMORY AND REGISTERS
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3.4 Self-check ROM
There are two areas of self-check ROM (ROMI and ROMII) located from $0200 to $02BF (192
bytes) and $1F00 to $1FEF (240 bytes) respectively.
Figure 3-1 Memory map of the MC68HC05B6
MC68HC05B6 MOTOROLA
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MEMORY AND REGISTERS
3
3.5 EEPROM
The user EEPROM consists of 256 bytes of memory located from address $0100 to $01FF. 255
bytes are general purpose and 1 byte is used by the option register. The non-volatile EEPROM is
byte erasable.
An internal charge pump provides the EEPROM voltage (VPP1), which removes the need to supply
a high voltage for erase and programming functions. The charge pump is a capacitor/diode ladder
network which will give a very high impedance output of around 20-30 M. The voltage of the
charge pump is visible at the VPP1 pin. During normal operation of the device, where
programming/erasing of the EEPROM array will occur, VPP1 should ne ver be connected to either
VDD or VSS as this could pre vent the charge pump reaching the necessary programming voltage.
Where it is considered dangerous to leave VPP1 unconnected for reasons of excessive noise in
a system, it may be tied to VDD; this will protect the EEPROM data but will also increase power
consumption, and therefore it is recommended that the protect bit function is used for regular
protection of EEPROM data (see Section 3.5.5).
In order to achie ve a higher degree of security for stored data, there is no capability for bulk or row
erase operations.
The EEPROM control register ($0007) provides control of the EEPROM programming and erase
operations.
Warning: The VPP1 pin should never be connected to VSS, as this could cause permanent
damage to the device.
3.5.1 EEPROM control register
ECLK
See Section 4.3 for a description of this bit.
E1ERA — EEPROM erase/programming bit
Providing the E1LAT and E1PGM bits are at logic one, this bit indicates whether the access to the
EEPROM is for erasing or programming purposes.
1 (set) – An erase operation will take place.
0 (clear) – A programming operation will take place.
Once the program/erase EEPROM address has been selected, E1ERA cannot be changed.
Address bit 7 bit 6 bit 5 bit 4 bit 3 bit 2 bit 1 bit 0 State
on reset
EEPROM/ECLK control $0007 0 0 0 0 ECLK E1ERA E1LAT E1PGM 0000 0000
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E1LAT — EEPROM programming latch enable bit
1 (set) – Address and data can be latched into the EEPROM for further
program or erase operations, providing the E1PGM bit is cleared.
0 (clear) – Data can be read from the EEPROM. The E1ERA bit and the
E1PGM bit are reset to zero when E1LAT is ‘0’.
STOP, power-on and external reset clear the E1LAT bit.
Note:
After the tERA1 erase time or tPROG1 programming time, the E1LAT bit has to be reset
to zero in order to clear the E1ERA bit and the E1PGM bit.
E1PGM — EEPROM charge pump enable/disable
1 (set) – Internal charge pump generator switched on.
0 (clear) – Internal charge pump generator switched off.
When the charge pump generator is on, the resulting high voltage is applied to the EEPROM array.
This bit cannot be set before the data is selected, and once this bit has been set it can only be
cleared by clearing the E1LAT bit.
A summary of the effects of setting/clearing bits 0, 1 and 2 of the control register are giv e in Table 3-1.
Note:
All combinations are not shown in the above table, since the E1PGM and E1ERA bits
are cleared when the E1LAT bit is at zero, and will result in a read condition.
Table 3-1 EEPROM control bits description
E1ERA E1LAT E1PGM Description
0 0 0 Read condition
0 1 0 Ready to load address/data for program/erase
0 1 1 Byte programming in progress
1 1 0 Ready for byte erase (load address)
1 1 1 Byte erase in progress
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3.5.2 EEPROM read operation
To be able to read from EEPROM, the E1LAT bit has to be at logic zero, as shown in Table 3-1.
While this bit is at logic zero, the E1PGM bit and the E1ERA bit are permanently reset to zero and
the 256 bytes of EEPROM may be read as if it were a normal ROM area. The internal charge
pump generator is automatically switched off since the E1PGM bit is reset.
If a read operation is executed while the E1LAT bit is set (erase or programming sequence), data
resulting from the operation will be $FF.
Note:
When not performing any programming or erase operation, it is recommended that
EEPROM should remain in the read mode (E1LAT = 0)
3.5.3 EEPROM erase operation
To erase the contents of a byte of the EEPROM, the following steps should be taken:
1 Set the E1LAT bit.
2 Set the E1ERA bit (1& 2 may be done simultaneously with the same
instruction).
3 Write address/data to the EEPROM address to be erased.
4 Set the E1PGM bit.
5 Wait for a time tERA1.
6 Reset the E1LAT bit (to logic zero).
While an erase operation is being performed, any access of the EEPROM array will not be
successful.
The erased state of the EEPROM is $FF and the programmed state is $00.
Note:
Data written to the address to be erased is not used, therefore its value is not
significant.
If a second word is to be erased, it is important that the E1LAT bit be reset before restarting the
erasing sequence otherwise any write to a new address will have no eff ect. This condition provides
a higher degree of security for the stored data.
User programs must be running from the RAM or R OM as the EEPROM will have its address and
data buses latched.
MOTOROLA
3-6 MC68HC05B6MEMORY AND REGISTERS
3
3.5.4 EEPROM programming operation
To program a byte of EEPROM, the following steps should be taken:
1 Set the E1LAT bit.
2 Write address/data to the EEPROM address to be programmed.
3 Set the E1PGM bit.
4 Wait for time tPROG1.
5 Reset the E1LAT bit (to logic zero).
While a programming operation is being performed, any access of the EEPROM array will not be
successful.
Warning: To program a byte correctly, it has to have been previously erased.
If a second word is to be programmed, it is important that the E1LAT bit be reset before restarting
the programming sequence otherwise any write to a new address will have no effect. This
condition provides a higher degree of security for the stored data.
User programs must be running from the RAM or R OM as the EEPROM will have its address and
data buses latched.
Note:
224 bytes of EEPROM (address $0120 to $01FF) can be prog ram and erase protected
under the control of bit 1 of the OPTR register detailed in Section 3.5.5.
3.5.5 Options register (OPTR)
This register (OPTR), located at $0010, contains the secure and protect functions for the
EEPROM and allows the user to select options in a non-volatile manner. The contents of the
OPTR register are loaded into data latches with each power-on or external reset.
(1) This register is implemented in EEPROM; therefore reset has no effect on the individual bits.
Address bit 7 bit 6 bit 5 bit 4 bit 3 bit 2 bit 1 bit 0 State
on reset
Options (OPTR)(1) $0100
EE1P SEC Not affected
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MEMORY AND REGISTERS
3
EE1P – EEPROM protect bit
In order to achieve a higher degree of protection, the EEPROM is effectively split into two parts,
both working from the VPP1 charge pump. Part 1 of the EEPROM array (32 bytes from $0100 to
$011F) cannot be protected; part 2 (224 bytes from $0120 to $01FF) is protected by the EE1P bit
of the options register.
1 (set) – Part 2 of the EEPROM array is not protected; all 256 b ytes of EEPROM
can be accessed f or any read, er ase or programming operations
0 (clear) – Part 2 of the EEPROM array is protected; any attempt to erase or
program a location will be unsuccessful
When this bit is set to 1 (erased), the protection will remain until the next power-on or external
reset. EE1P can only be written to ‘0’ when the ELAT bit in the EEPROM control register is set.
SEC – Security bit
This high security bit allows the user to secure the EEPROM data from external accesses. When
the SEC bit is at ‘0’, the EEPROM contents are secured b y preventing any entry to test mode . The
only way to erase the SEC bit to ‘1’ externally is to enter self-check mode, at which time the entire
EEPROM contents will be er ased. When the SEC bit is changed, its new value will have no effect
until the next external or power-on reset.
3.6 EEPROM during STOP mode
When entering STOP mode, the EEPROM is automatically set to the read mode and the VPP1
high voltage charge pump generator is automatically disabled.
3.7 EEPROM during WAIT mode
The EEPROM is not affected by WAIT mode. Any program/erase operation will continue as in
normal operating mode. The charge pump is not affected by WAIT mode, therefore it is possible
to wait the tERA1 erase time or tPROG1 programming time in WAIT mode.
Under normal operating conditions, the charge pump generator is driven by the internal CPU
clocks. When the operating frequency is low, e.g. during WAIT mode, the clocking should be done
by the internal A/D RC oscillator. The RC oscillator is enabled by setting the ADRC bit of the A/D
status/control register at $0009.
MOTOROLA
3-8 MC68HC05B6MEMORY AND REGISTERS
3
(1) The POR bit is set each time there is a power-on reset.
(2) The state of the WDOG bit after reset is dependent on the mask option selected; 1=watchdog enabled, 0=watchdog disabled.
(3) This register is implemented in EEPROM; therefore reset has no effect on the individual bits.
Table 3-2 Register outline
Register name Address bit 7 bit 6 bit 5 bit 4 bit 3 bit 2 bit 1 bit 0 State on
reset
Port A data (PORTA) $0000 Undefined
Port B data (PORTB) $0001 Undefined
Port C data (PORTC) $0002 PC2/
ECLK Undefined
Port D data (PORTD) $0003 PD7 PD6 PD5 PD4 PD3 PD2 PD1 PD0 Undefined
Port A data direction (DDRA) $0004 0000 0000
Port B data direction (DDRB) $0005 0000 0000
Port C data direction (DDRC) $0006 0000 0000
EEPROM/ECLK control $0007 0 0 0 0 ECLK E1ERA E1LAT E1PGM 0000 0000
A/D data (ADDATA) $0008 0000 0000
A/D status/control (ADSTAT) $0009 COCO ADRC ADON 0 CH3 CH2 CH1 CH0 0000 0000
Pulse length modulation A (PLMA) $000A 0000 0000
Pulse length modulation B (PLMB) $000B 0000 0000
Miscellaneous $000C POR(1) INTP INTN INTE SFA SFB SM WDOG(2) ?001 000?
SCI baud rate (BAUD) $000D SPC1 SPC0 SCT1 SCT0 SCT0 SCR2 SCR1 SCR0 00uu uuuu
SCI control 1 (SCCR1) $000E R8 T8
M WAKE CPOL CPHA LBCL Undefined
SCI control 2 (SCCR2) $000F TIE TCIE RIE ILIE TE RE RWU SBK 0000 0000
SCI status (SCSR) $0010 TDRE TC RDRF IDLE OR NF FE 1100 000u
SCI data (SCDR) $0011 0000 0000
Timer control (TCR) $0012 ICIE OCIE TOIE FOLV2 FOLV1 OLV2 IEDG1 OLVL1 0000 00u0
Timer status (TSR) $0013 ICF1 OCF1 TOF ICF2 OCF2 Undefined
Input capture high 1 $0014 Undefined
Input capture low 1 $0015 Undefined
Output compare high 1 $0016 Undefined
Output compare low 1 $0017 Undefined
Timer counter high $0018 1111 1111
Timer counter low $0019 1111 1100
Alternate counter high $001A 1111 1111
Alternate counter low $001B 1111 1100
Input capture high 2 $001C Undefined
Input capture low 2 $001D Undefined
Output compare high 2 $001E Undefined
Output compare low 2 $001F Undefined
Options (OPTR)(3) $0100 EE1P SEC Not affected
MC68HC05B6 MOTOROLA
3-9
MEMORY AND REGISTERS
3
3.8 Miscellaneous register
POR — Power-on reset bit (see Section 9.1)
This bit is set each time the device is powered on. Therefore, the state of the POR bit allows the
user to make a software distinction between a power-on and an external reset. This bit cannot be
set by software and is cleared by writing it to zero.
1 (set) – A power-on reset has occurred.
0 (clear) – No power-on reset has occurred.
INTP, INTN — External interrupt sensitivity options (see Section 9.2)
These two bits allow the user to select which edge the IRQ pin will be sensitive to (see Table 3-3).
Both bits can be written to only while the I-bit is set, and are cleared by power-on or external reset,
thus the device is initialised with negative edge and low level sensitivity.
INTE — External interrupt enable (see Section 9.2)
1 (set) – External interrupt function (IRQ) enabled.
0 (clear) – External interrupt function (IRQ) disabled.
The INTE bit can be written to only while the I-bit is set, and is set by power-on or external reset,
thus enabling the external interrupt function.
(1) The POR bit is set each time there is a power-on reset.
(2) The state of the WDOG bit after reset is dependent on the mask option selected; 1=watchdog enabled, 0=watchdog disabled.
Address bit 7 bit 6 bit 5 bit 4 bit 3 bit 2 bit 1 bit 0 State
on reset
Miscellaneous $000C POR(1) INTP INTN INTE SFA SFB SM WDOG(2) ?001 000?
Table 3-3
IRQ sensitivity
INTP INTN IRQ sensitivity
0 0 Negative edge and low level sensitive
0 1 Negative edge only
1 0 Positive edge only
1 1 Positive and negative edge sensitive
MOTOROLA
3-10 MC68HC05B6MEMORY AND REGISTERS
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SFA — Slow or fast mode selection for PLMA (see Section 7.1)
This bit allows the user to select the slow or fast mode of the PLMA pulse length modulation
output.
1 (set) – Slow mode PLMA (4096 x timer clock period).
0 (clear) – Fast mode PLMA (256 x timer clock period).
SFB — Slow or fast mode selection for PLMB (see Section 7.1)
This bit allows the user to select the slow or fast mode of the PLMB pulse length modulation
output.
1 (set) – Slow mode PLMB (4096 x timer clock period).
0 (clear) – Fast mode PLMB (256 x timer clock period).
Note:
The highest speed of the PLM system corresponds to the frequency of the TOF bit
being set, multiplied by 256. The lowest speed of the PLM system corresponds to the
frequency of the TOF bit being set, multiplied by 16.
Warning: Because the SF A bit and SFB bit are not doub le buffered, it is mandatory to set the SF A
bit and SFB bit to the desired values before writing to the PLM registers; not doing so
could temporarily give incorrect values at the PLM outputs.
SM — Slow mode (see Section 2.4.3)
1 (set) – The system runs at a bus speed 16 times lower than normal
(fOSC/32). SLOW mode affects all sections of the device, including
SCI, A/D and timer.
0 (clear) – The system runs at normal bus speed (fOSC/2).
The SM bit is cleared by external or power-on reset. The SM bit is automatically cleared when
entering STOP mode.
WDOG — Watchdog enable/disable (see Section 9.1.4)
The WDOG bit can be used to enable the watchdog timer previously disabled by a mask option.
Following a watchdog reset the state of the WDOG bit is as defined by the mask option specified.
1 (set) – Watchdog counter cleared and enabled.
0 (clear) – The watchdog cannot be disabled by software; writing a zero to this
bit has no effect.
MC68HC05B6 MOTOROLA
4-1
INPUT/OUTPUT PORTS
4
4
INPUT/OUTPUT PORTS
In single-chip mode, the MC68HC05B6 has a total of 24 I/O lines, arranged as three 8-bit por ts
(A, B and C), and eight input-only lines, arranged as one 8-bit port (D). Each I/O line is individually
programmable as either input or output, under the software control of the data direction registers.
The 8-bit input-only port (D) shares its pins with the A/D converter, when the A/D converter is
enabled. To avoid glitches on the output pins, data should be written to the I/O por t data register
before writing ones to the corresponding data direction register bits to set the pins to output mode.
4.1 Input/output programming
The bidirectional port lines may be programmed as inputs or outputs under software control. The
direction of each pin is determined by the state of the corresponding bit in the port data direction
register (DDR). Each por t has an associated DDR. Any I/O port pin is configured as an output if
its corresponding DDR bit is set to a logic one. A pin is configured as an input if its corresponding
DDR bit is cleared to a logic zero.
At power-on or reset, all DDRs are cleared, thus configuring all port pins as inputs. The data
direction registers can be written to or read by the MCU. During the programmed output state, a
read of the data register actually reads the value of the output data latch and not the I/O pin. The
operation of the standard port hardware is shown schematically in Figure 4-1.
MOTOROLA
4-2 MC68HC05B6INPUT/OUTPUT PORTS
4
Table 4-1 shows the effect of reading from or writing to an I/O pin in various circumstances. Note
that the read/write signal shown is internal and not available to the user.
4.2 Ports A and B
These ports are standard M68HC05 bidirectional I/O por ts, each comprising a data register and
a data direction register.
Reset does not affect the state of the data register, but clears the data direction register, thereby
returning all port pins to input mode. Writing a ‘1’ to any DDR bit sets the corresponding port pin
to output mode.
Figure 4-1 Standard I/O port structure
Table 4-1 I/O pin states
R/W DDRn Action of MCU write to/read of data bit
0 0 The I/O pin is in input mode. Data is written into the output data latch.
0 1 Data is written into the output data latch, and output to the I/O pin.
1 0 The state of the I/O pin is read.
1 1 The I/O pin is in output mode. The output data latch is read.
Latched data
register bit
DDRn
DATA
Input
buffer
Output
buffer
O/P
data
buffer
M68HC05 internal connections
DDRn DATA I/O Pin
1 0 0
1 1 1
0 0 tristate
0 1 tristate
I/O
Pin
Output
Input
Data direction
register bit
MC68HC05B6 MOTOROLA
4-3
INPUT/OUTPUT PORTS
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4.3 Port C
In addition to the standard port functions described for port A and B, port C pin 2 can be
configured, using the ECLK bit of the EEPROM/ECLK control register, to output the CPU clock. If
this is selected the corresponding DDR bit is automatically set and bit 2 of port C will always read
the output data latch. The other port C pins are not affected by this feature.
ECLK — External clock output bit
1 (set) – ECLK CPU clock is output on PC2.
0 (clear) –ECLK CPU clock is not output on PC2; port C acts as a normal I/O port.
The ECLK bit is cleared by po wer-on or external reset. It is not affected b y the execution of a STOP
or WAIT instruction.
The timing diagram of the clock output is shown in Figure 4-2.
4.4 Port D
This 8-bit input-only port shares its pins with the A/D converter subsystem. When the A/D
converter is enabled, pins PD0-PD7 read the eight analog inputs to the A/D converter. Port D can
be read at any time, however, if it is read during an A/D conversion sequence noise, may be
injected on the analog inputs, resulting in reduced accuracy of the A/D. Furthermore, performing
Address bit 7 bit 6 bit 5 bit 4 bit 3 bit 2 bit 1 bit 0 State
on reset
EEPROM/ECLK control $0007 0 0 0 0 ECLK E1ERA E1LAT E1PGM 0000 0000
Figure 4-2 ECLK timing diagram
Internal clock (PHI2)
External clock (ECLK/PC2)
Output port (if write to output port)
MOTOROLA
4-4 MC68HC05B6INPUT/OUTPUT PORTS
4
a digital read of por t D with levels other than VDD or VSS on the por t D pins will result in greater
power dissipation during the read cycle.
As port D is an input-only por t there is no DDR associated with it. Also, at power up or external
reset, the A/D converter is disabled, thus the port is configured as a standard input-only port.
Note:
It is recommended that all unused input ports and I/O ports be tied to an appropriate
logic level (i.e. either VDD or VSS).
4.5 Port registers
The following sections explain in detail the individual bits in the data and control registers
associated with the ports.
4.5.1 Port data registers A and B (PORTA and PORTB)
Each bit can be configured as input or output via the corresponding data direction bit in the por t
data direction register (DDRx).
The state of the port data registers following reset is not defined.
4.5.2 Port data register C (PORTC)
Each bit can be configured as input or output via the corresponding data direction bit in the por t
data direction register (DDRx).
In addition, bit 2 of port C is used to output the CPU clock if the ECLK bit in the EEPROM
CTL/ECLK register is set (see Section 4.3).
The state of the port data registers following reset is not defined.
Address bit 7 bit 6 bit 5 bit 4 bit 3 bit 2 bit 1 bit 0 State
on reset
Port A data (PORTA) $0000 Undefined
Port B data (PORTB) $0001 Undefined
Address bit 7 bit 6 bit 5 bit 4 bit 3 bit 2 bit 1 bit 0 State
on reset
Port C data (PORTC) $0002 PC2/
ECLK Undefined
MC68HC05B6 MOTOROLA
4-5
INPUT/OUTPUT PORTS
4
4.5.3 Port data register D (PORTD)
All the port D bits are input-only and are shared with the A/D con verter. The function of each bit is
determined by the ADON bit in the A/D status/control register.
The state of the port data registers following reset is not defined.
4.5.3.1 A/D status/control register
ADON — A/D converter on
1 (set) – A/D converter is switched on; all port D pins act as analog inputs for
the A/D converter.
0 (clear) – A/D converter is switched off; all port D pins act as input only pins.
Reset clears the ADON bit, thus configuring port D as an input only port.
4.5.4 Data direction registers (DDRA, DDRB and DDRC)
Writing a ‘1’ to any bit configures the corresponding port pin as an output; conversely, writing any
bit to ‘0’ configures the corresponding port pin as an input.
Reset clears these registers, thus configuring all ports as inputs.
Address bit 7 bit 6 bit 5 bit 4 bit 3 bit 2 bit 1 bit 0 State
on reset
Port D data (PORTD) $0003 PD7 PD6 PD5 PD4 PD3 PD2 PD1 PD0 Undefined
Address bit 7 bit 6 bit 5 bit 4 bit 3 bit 2 bit 1 bit 0 State
on reset
A/D status/control $0009 COCO ADRC ADON 0 CH3 CH2 CH1 CH0 0000 0000
Address bit 7 bit 6 bit 5 bit 4 bit 3 bit 2 bit 1 bit 0 State
on reset
Port A data direction (DDRA) $0004 0000 0000
Port B data direction (DDRB) $0005 0000 0000
Port C data direction (DDRC) $0006 0000 0000
MOTOROLA
4-6 MC68HC05B6INPUT/OUTPUT PORTS
4
4.6 Other port considerations
All output ports can emulate ‘open-drain’ outputs. This is achie ved by writing a z ero to the relevant
output port latch. By toggling the corresponding data direction bit, the por t pin will either be an
output zero or tri-state (an input). This is shown diagrammatically in Figure 4-3.
When using a por t pin as an ‘open-drain’ output, cer tain precautions must be taken in the user
software. If a read-modify-wr ite instruction is used on a por t where the ‘open-drain’ is assigned
and the pin at this time is programmed as an input, it will read it as a ‘one’. The read-modify-write
instruction will then write this ‘one’ into the output data latch on the next cycle. This would cause
the ‘open-drain’ pin not to output a ‘zero’ when desired.
Note:
‘Open-drain’ outputs should not be pulled above VDD.
Figure 4-3 Port logic levels
DDRn A Y
(b)
100
Normal operation – tri state
111
0 0 tri state
0 1 tri state
1 0 low
‘Open-drain’
1 1 —
0 0 high
0 1 high
Y
A
Read buffer output
Data direction register bit DDRn
Px0
VDD
VDD
DDRx, bit 0 = 0
Portx, bit 0 = 0 DDRx, bit 0 = 0
Portx, bit 0 = 0
(c)
(a)
‘Open-drain’ output
MC68HC05B6 MOTOROLA
5-1
PROGRAMMABLE TIMER
5
5
PROGRAMMABLE TIMER
The programmable timer on the MC68HC05B6 consists of a 16-bit read-only free-running counter ,
with a fix ed divide-by-four prescaler , plus the input capture/output compare circuitry. The timer can
be used for many purposes including measuring pulse length of two input signals and generating
two output signals. Pulse lengths for both input and output signals can vary from several
microseconds to many seconds. In addition, it works in conjunction with the pulse width
modulation (PLM) system to execute two 8-bit D/A PLM (pulse length modulation) conversions,
with a choice of two repetition rates. The timer is also capable of generating periodic interrupts or
indicating passage of an arbitrary multiple of f our CPU cycles . A block diagram is shown in Figure
5-1, and timing diagrams are shown in Figure 5-2, Figure 5-3, Figure 5-4 and Figure 5-5.
The timer has a 16-bit architecture, hence each specific functional segment is represented b y two
8-bit registers (e xcept the PLMA and PLMB which use one 8-bit register for each). These registers
contain the high and low byte of that functional segment. Accessing the low byte of a specific timer
function allows full control of that function; however, an access of the high byte inhibits that specific
timer function until the low byte is also accessed.
The 16-bit programmable timer is monitored and controlled by a group of sixteen registers, full
details of which are contained in this section.
Note:
A problem may arise if an interrupt occurs in the time between the high and low bytes
being accessed. To prevent this, the I-bit in the condition code register (CCR) should be
set while manipulating both the high and low byte register of a specific timer function,
ensuring that an interrupt does not occur.
5.1 Counter
The key element in the programmable timer is a 16-bit, free-running counter or counter register,
preceded by a prescaler that divides the internal processor clock by four. The prescaler gives the
timer a resolution of 2s if the internal bus cloc k is 2 MHz. The counter is incremented dur ing the
low portion of the inter nal bus clock. Software can read the counter at any time without affecting
its value.
MOTOROLA
5-2 MC68HC05B6PROGRAMMABLE TIMER
5
Figure 5-1 16-bit programmable timer block diagram
Internal
Internal bus
8
Output
compare
register 1
processor
clock
+
+
8-bit
buffer
4
High Low
16-bit
free-running
counter
Counter
alternate
register
register 1
register 2 Input capture
Internal timer bus
Overflow
detect
circuit
Edge
detect
TCAP1
TCMP2
TCMP1
Latch
D
C
Q
compare
Output register 2
Input capture
byte byte
High
byte Low
byte
High
byte Low
byte High
byte Low
byte Low
byte
High
byte
circuit 1
compare
Output
circuit 2
compare
Output
circuit 1
Edge
detect
circuit 2 TCAP2
pin
pin
pin
pin
D
C
Q
Latch
76543Timer status
register Timer control
$0013
$0012
$0018
$0019
$001A
$001B
$001C
$0016
$0017 $0014
$0015
$001E
$001F $001D
To PLM
register
ICF1 OCF1 TOF ICF2 OCF2
ICIE OCIE TOIE FOLV2 OLVL2 IEDG1 OLVL1
FOLV1
Interrupt circuit
Input capture
interrupt
$1FF8,9
Output compare
interrupt
$1FF6,7
Overflow interrupt
$1FF4,5
COP watchdog
counter input
MC68HC05B6 MOTOROLA
5-3
PROGRAMMABLE TIMER
5
5.1.1 Counter register and alternate counter register
The double-byte, free-running counter can be read from either of two locations, $18-$19 (counter
register) or $1A-$1B (alternate counter register). A read from only the less significant byte (LSB)
of the free-running counter ($19 or $1B) receives the count value at the time of the read. If a read
of the free-running counter or alternate counter register first addresses the more significant byte
(MSB) ($18 or $1A), the LSB is transferred to a buffer. This buffer value remains fix ed after the first
MSB read, even if the user reads the MSB several times. This buffer is accessed when reading
the free-running counter or alter nate counter register LSB and thus completes a read sequence
of the total counter value. In reading either the free-running counter or alternate counter register,
if the MSB is read, the LSB must also be read to complete the sequence . If the timer overflow flag
(TOF) is set when the counter register LSB is read then a read of the timer status register (TSR)
will clear the flag.
The alternate counter register diff ers from the counter register only in that a read of the LSB does
not clear TOF. Therefore, where it is critical to avoid the possibility of missing timer overflow
interrupts due to clearing of TOF, the alternate counter register should be used.
The free-running counter is set to $FFFC during power-on and external reset and is always a
read-only register . During a power-on reset, the counter begins running after the oscillator start-up
delay. Because the free-running counter is 16 bits preceded by a fixed divide-by-4 prescaler, the
value in the free-running counter repeats e very 262,144 internal bus clock cycles. TOF is set when
the counter overflows (from $FFFF to $0000); this will cause an interrupt if TOIE is set.
In some par ticular timing control applications it may be desirable to reset the 16-bit free running
counter under software control. When the low byte of the counter ($19 or $1B) is wr itten to, the
counter is configured to its reset value ($FFFC).
The divide-by-4 prescaler is also reset and the counter resumes normal counting operation. All of
the flags and enable bits remain unaltered by this operation. If access has previously been made
to the high byte of the free-running counter ($18 or $1A), then the reset counter operation
terminates the access sequence.
Warning: This operation may affect the function of the watchdog system (see Section 9.1.4). The
PLM results will also be affected while resetting the counter.
Address bit 7 bit 6 bit 5 bit 4 bit 3 bit 2 bit 1 bit 0 State
on reset
Timer counter high $0018 1111 1111
Timer counter low $0019 1111 1100
Address bit 7 bit 6 bit 5 bit 4 bit 3 bit 2 bit 1 bit 0 State
on reset
Alternate counter high $001A 1111 1111
Alternate counter low $001B 1111 1100
MOTOROLA
5-4 MC68HC05B6PROGRAMMABLE TIMER
5
5.2 Timer control and status
The various functions of the timer are monitored and controlled using the timer control and status
registers described below.
5.2.1 Timer control register (TCR)
The timer control register ($0012) is used to enable the input captures (ICIE), output compares
(OCIE), and timer overflow (TOIE) functions as well as forcing output compares (FOLV1 and
FOLV2), selecting input edge sensitivity (IEDG1) and levels of output polarity (OLV1 and OLV2).
ICIE — Input captures interrupt enable
If this bit is set, a timer interrupt is enabled whenever the ICF1 or ICF2 status flag (in the timer
status register) is set.
1 (set) – Interrupt enabled.
0 (clear) – Interrupt disabled.
OCIE — Output compares interrupt enable
If this bit is set, a timer interrupt is enabled whenever the OCF1 or OCF2 status flag (in the timer
status register) is set.
1 (set) – Interrupt enabled.
0 (clear) – Interrupt disabled.
TOIE — Timer overflow interrupt enable
If this bit is set, a timer interrupt is enabled whenever the TOF status flag (in the timer status
register) is set.
1 (set) – Interrupt enabled.
0 (clear) – Interrupt disabled.
Address bit 7 bit 6 bit 5 bit 4 bit 3 bit 2 bit 1 bit 0 State
on reset
Timer control (TCR) $0012 ICIE OCIE TOIE FOLV2 FOLV1 OLV2 IEDG1 OLVL1 0000 00u0
MC68HC05B6 MOTOROLA
5-5
PROGRAMMABLE TIMER
5
FOLV2 — Force output compare 2
This bit always reads as zero, hence writing a zero to this bit has no effect. Wr iting a one at this position
will f orce the OLV2 bit to the corresponding output le vel latch, thus appearing at the TCMP2 pin. Note
that this bit does not aff ect the OCF2 bit of the status register (see Section 5.4.3).
1 (set) – OLV2 bit forced to output level latch.
0 (clear) – No effect.
FOLV1 — Force output compare 1
This bit always reads as zero, hence writing a zero to this bit has no effect. Wr iting a one at this position
will f orce the OLV1 bit to the corresponding output le vel latch, thus appearing at the TCMP1 pin. Note
that this bit does not aff ect the OCF1 bit of the status register (see Section 5.4.3).
1 (set) – OLV1 bit forced to output level latch.
0 (clear) – No effect.
OLV2 — Output level 2
When OLV2 is set a high output level will be clocked into the output level register by the next
successful output compare, and will appear on the TCMP2 pin. When clear, it will be a low level
which will appear on the TCMP2 pin.
1 (set) – A high output level will appear on the TCMP2 pin.
0 (clear) – A low output level will appear on the TCMP2 pin.
IEDG1 — Input edge 1
When IEDG1 is set, a positive-going edge on the TCAP1 pin will trigger a transfer of the
free-running counter value to the input capture register 1. When clear, a negative-going edge
triggers the transfer.
1 (set) – TCAP1 is positive-going edge sensitive.
0 (clear) – TCAP1 is negative-going edge sensitive.
Note:
There is no need for an equivalent bit for the input capture register 2 as TCAP2 is
negative-going edge sensitive only.
OLV1 — Output level 1
When OLV1 is set a high output level will be clocked into the output level register by the next
successful output compare, and will appear on the TCMP1 pin. When clear, it will be a low level
which will appear on the TCMP1 pin.
1 (set) – A high output level will appear on the TCMP1 pin.
0 (clear) – A low output level will appear on the TCMP1 pin.
MOTOROLA
5-6 MC68HC05B6PROGRAMMABLE TIMER
5
5.2.2 Timer status register (TSR)
The timer status register ($13) contains the status bits corresponding to the four timer interrupt
conditions – ICF1,OCF1, TOF, ICF2 and OCF2.
Accessing the timer status register satisfies the first condition required to clear the status bits. The
remaining step is to access the register corresponding to the status bit.
ICF1 — Input capture flag 1
This bit is set when the selected polarity of edge is detected by the input capture edge detector 1
at TCAP1; an input capture interrupt will be generated, if ICIE is set. ICF1 is cleared by reading
the TSR and then the input capture low register 1 ($15).
1 (set) – A valid input capture has occurred.
0 (clear) – No input capture has occurred.
OCF1 — Output compare flag 1
This bit is set when the output compare 1 register contents match those of the free-running
counter; an output compare interrupt will be generated if OCIE is set. OCF1 is cleared by reading
the TSR and then the output compare 1 low register ($17).
1 (set) – A valid output compare has occurred.
0 (clear) – No output compare has occurred.
TOF — Timer overflow status flag
This bit is set when the free-running counter overflows from $FFFF to $0000; a timer overflow interr upt
will occur if T OIE is set. TOF is cleared by reading the TSR and the counter lo w register ($19).
1 (set) – Timer overflow has occurred.
0 (clear) – No timer overflow has occurred.
When using the timer overflow function and reading the free-running counter at random times to
measure an elapsed time, a problem may occur whereby the timer overflow flag is unintentionally
cleared if:
1 The timer status register is read or written when TOF is set, and
2 The LSB of the free-running counter is read, but not for the purpose of
servicing the flag.
Reading the alternate counter register instead of the counter register will avoid this potential
problem.
Address bit 7 bit 6 bit 5 bit 4 bit 3 bit 2 bit 1 bit 0 State
on reset
Timer status (TSR) $0013 ICF1 OCF1 TOF ICF2 OCF2 Undefined
MC68HC05B6 MOTOROLA
5-7
PROGRAMMABLE TIMER
5
ICF2 — Input capture flag 2
This bit is set when a negative edge is detected by the input capture edge detector 2 at TCAP2;
an input capture interrupt will be generated if ICIE is set. ICF2 is cleared by reading the TSR and
then the input capture low register 2 ($1D).
1 (set) – A valid (negative) input capture has occurred.
0 (clear) – No input capture has occurred.
OCF2 — Output compare flag 2
This bit is set when the output compare 2 register contents match those of the free-running
counter; an output compare interrupt will be generated if OCIE is set. OCF2 is cleared by reading
the TSR and then the output compare 2 low register ($1F).
1 (set) – A valid output compare has occurred.
0 (clear) – No output compare has occurred.
5.3 Input capture
‘Input capture’ is a technique whereby an external signal is used to trigger a read of the free
running counter. In this way it is possible to relate the timing of an external signal to the inter nal
counter value, and hence to elapsed time.
There are two input capture registers: input capture register 1 (ICR1) and input capture register 2 (ICR2).
The same input capture interrupt enable bit (ICIE) is used for the two input captures.
5.3.1 Input capture register 1 (ICR1)
The two 8-bit registers that make up the 16-bit input capture register 1 are read-only, and are used
to latch the value of the free-running counter after the input capture edge detector circuit 1 senses
a valid transition at TCAP1. The level transition that triggers the counter transfer is defined by the
input edge bit (IEDG1). When an input capture 1 occurs, the corresponding flag ICF1 in TSR is
set. An interrupt can also accompany an input capture 1 provided the ICIE bit in TCR is set. The
8 most significant bits are stored in the input capture high 1 register at $14, the 8 least significant
bits in the input capture low 1 register at $15.
Address bit 7 bit 6 bit 5 bit 4 bit 3 bit 2 bit 1 bit 0 State
on reset
Input capture high 1 $0014 Undefined
Input capture low 1 $0015 Undefined
MOTOROLA
5-8 MC68HC05B6PROGRAMMABLE TIMER
5
The result obtained from an input capture will be one greater than the value of the free-r unning
counter on the rising edge of the internal bus clock preceding the external transition. This delay is
required for internal synchronization. Resolution is one count of the free-running counter, which is
four internal bus clock cycles. The free-running counter contents are transferred to the input
capture register 1 on each valid signal transition whether the input capture 1 flag (ICF1) is set or
clear. The input capture register 1 always contains the free-running counter value that
corresponds to the most recent input capture 1. After a read of the input capture 1 register MSB
($14), the counter transfer is inhibited until the LSB ($15) is also read. This characteristic causes
the time used in the input capture software routine and its interaction with the main program to
determine the minimum pulse per iod. A read of the input capture 1 register LSB ($15) does not
inhibit the free-running counter transfer since the two actions occur on opposite edges of the
internal bus clock.
Reset does not aff ect the contents of the input capture 1 register, e xcept when exiting ST OP mode
(see Section 5.6).
5.3.2 Input capture register 2 (ICR2)
The two 8-bit registers that make up the 16-bit input capture register 2 are read-only, and are used
to latch the value of the free-running counter after the input capture edge detector circuit 2 senses
a negative transition at pin TCAP2. When an input capture 2 occurs, the corresponding flag ICF2
in TSR is set. An interrupt can also accompany an input capture 2 provided the ICIE bit in TCR is
set.The 8 most significant bits are stored in the input capture 2 high register at $1C, the 8 least
significant bits in the input capture 2 low register at $1D.
The result obtained from an input capture will be one greater than the value of the free-r unning
counter on the rising edge of the internal bus clock preceding the external transition. This delay is
required for internal synchronization. Resolution is one count of the free-running counter, which is
four internal bus clock cycles. The free-running counter contents are transferred to the input
capture register 2 on each negative signal transition whether the input capture 2 flag (IC2F) is set
or clear. The input capture register 2 always contains the free-running counter value that
corresponds to the most recent input capture 2. After a read of the input capture register 2 MSB
($1C), the counter transfer is inhibited until the LSB ($1D) is also read. This characteristic causes
the time used in the input capture software routine and its interaction with the main program to
determine the minimum pulse per iod. A read of the input capture register 2 LSB ($1C) does not
inhibit the free-running counter transfer since the two actions occur on opposite edges of the
internal bus clock.
Reset does not aff ect the contents of the input capture 2 register, e xcept when exiting ST OP mode
(see Section 5.6).
Address bit 7 bit 6 bit 5 bit 4 bit 3 bit 2 bit 1 bit 0 State
on reset
Input capture high 2 $001C Undefined
Input capture low 2 $001D Undefined
MC68HC05B6 MOTOROLA
5-9
PROGRAMMABLE TIMER
5
5.4 Output compare
‘Output compare’ is a technique which may be used, for e xample, to generate an output waveform,
or to signal when a specific time period has elapsed, by presetting the output compare register to
the appropriate value.
There are two output compare registers: output compare register 1 (OCR1) and output compare
register 2 (OCR2).
Note:
The same output compare interrupt enable bit (OCIE) is used for the two output
compares.
5.4.1 Output compare register 1 (OCR1)
The 16-bit output compare register 1 is made up of two 8-bit registers at locations $16 (MSB) and
$17 (LSB). The contents of the output compare register 1 are compared with the contents of the
free-running counter continually and, if a match is found, the corresponding output compare flag
(OCF1) in the timer status register is set and the output le vel (OLVL1) is transferred to pin TCMP1.
The output compare register 1 values and the output level bit should be changed after each
successful comparison to establish a new elapsed timeout. An interrupt can also accompany a
successful output compare provided the corresponding interrupt enable bit (OCIE) is set. (The
free-running counter is updated every four internal bus clock cycles.)
After a processor write cycle to the output compare register 1 containing the MSB ($16), the output
compare function is inhibited until the LSB ($17) is also written. The user must write both bytes
(locations) if the MSB is written first. A write made only to the LSB ($17) will not inhibit the compare
1 function. The processor can write to either byte of the output compare register 1 without aff ecting
the other byte. The output level (OLVL1) bit is clocked to the output le vel register and hence to the
TCMP1 pin whether the output compare flag 1 (OCF1) is set or clear. The minimum time required
to update the output compare register 1 is a function of the program rather than the internal
hardware. Because the output compare flag 1 and the output compare register 1 are not defined
at power on, and not affected by reset, care must be taken when initializing output compare
functions with software. The following procedure is recommended:
– Write to output compare high 1 to inhibit further compares;
– Read the timer status register to clear OCF1 (if set);
– Write to output compare low 1 to enable the output compare 1 function.
Address bit 7 bit 6 bit 5 bit 4 bit 3 bit 2 bit 1 bit 0 State
on reset
Output compare high 1 $0016 Undefined
Output compare low 1 $0017 Undefined
MOTOROLA
5-10 MC68HC05B6PROGRAMMABLE TIMER
5
The purpose of this procedure is to pre vent the OCF1 bit from being set between the time it is read
and the write to the corresponding output compare register.
All bits of the output compare register are readable and writable and are not altered by the timer
hardware or reset. If the compare function is not needed, the two bytes of the output compare
register can be used as storage locations.
5.4.2 Output compare register 2 (OCR2)
The 16-bit output compare register 2 is made up of two 8-bit registers at locations $1E (MSB) and
$1F (LSB). The contents of the output compare register 2 are compared with the contents of the
free-running counter continually and, if a match is found, the corresponding output compare flag
(OCF2) in the timer status register is set and the output le vel (OLVL2) is transferred to pin TCMP2.
The output compare register 2 values and the output level bit should be changed after each
successful comparison to establish a new elapsed timeout. An interrupt can also accompany a
successful output compare provided the corresponding interrupt enable bit (OCIE) is set. (The
free-running counter is updated every four internal bus clock cycles.)
After a processor write cycle to the output compare register 2 containing the MSB ($1E), the
output compare function is inhibited until the LSB ($1F) is also written. The user must write both
bytes (locations) if the MSB is written first. A write made only to the LSB ($1F) will not inhibit the
compare 2 function. The processor can write to either byte of the output compare register 2
without affecting the other byte. The output level (OLVL2) bit is clocked to the output level register
and hence to the TCMP2 pin whether the output compare flag 2 (OCF2) is set or clear. The
minimum time required to update the output compare register 2 is a function of the program rather
than the internal hardware. Because the output compare flag 2 and the output compare register
2 are not defined at power on, and not affected by reset, care must be taken when initializing
output compare functions with software. The following procedure is recommended:
– Write to output compare high 2 to inhibit further compares;
– Read the timer status register to clear OCF2 (if set);
– Write to output compare low 2 to enable the output compare 2 function.
Address bit 7 bit 6 bit 5 bit 4 bit 3 bit 2 bit 1 bit 0 State
on reset
Output compare high 2 $001E Undefined
Output compare low 2 $001F Undefined
MC68HC05B6 MOTOROLA
5-11
PROGRAMMABLE TIMER
5
The purpose of this procedure is to pre vent the OCF1 bit from being set between the time it is read
and the write to the corresponding output compare register.
All bits of the output compare register are readable and writable and are not altered by the timer
hardware or reset. If the compare function is not needed, the two bytes of the output compare
register can be used as storage locations.
5.4.3 Software force compare
A software f orce compare is required in many applications. To achieve this, bit 3 (FOLV1 f or OCR1)
and bit 4 (FOLV2 f or OCR2) in the timer control register are used. These bits always read as ‘z ero’,
but a write to ‘one’ causes the respective OLVL1 or OLVL2 values to be copied to the respective
output level (TCMP1 and TCMP2 pins).
Internal logic is arranged such that in a single instruction, one can change OLVL1 and/or OLVL2,
at the same time causing a forced output compare with the new values of OLVL1 and OLVL2. In
conjunction with normal compare, this function allows a wide range of applications including fixed
frequency generation.
Note:
A software force compare will affect the corresponding output pin TCMP1 and/or
TCMP2, but will not affect the compare flag, thus it will not generate an interrupt.
5.5 Pulse Length Modulation (PLM)
The programmable timer works in conjunction with the PLM system to execute two 8-bit D/A PLM
conversions, with a choice of two repetition rates (see Section 7).
5.5.1 Pulse length modulation registers A and B (PLMA/PLMB)
Address bit 7 bit 6 bit 5 bit 4 bit 3 bit 2 bit 1 bit 0 State
on reset
Pulse length modulation A (PLMA) $000A 0000 0000
Address bit 7 bit 6 bit 5 bit 4 bit 3 bit 2 bit 1 bit 0 State
on reset
Pulse length modulation B (PLMB) $000B 0000 0000
MOTOROLA
5-12 MC68HC05B6PROGRAMMABLE TIMER
5
5.6 Timer during STOP mode
When the MCU enters STOP mode, the timer counter stops counting and remains at that
particular count value until STOP mode is exited by an interrupt. If STOP mode is exited by
power-on or external reset, the counter is forced to $FFFC but if it is exited by external interrupt
(IRQ) then the counter resumes from its stopped value.
Another feature of the programmable timer is that if at least one valid input capture edge occurs
at one of the TCAP pins while in STOP mode, the corresponding input capture detect circuitr y is
armed. This action does not wake the MCU or set any timer flags, but when the MCU does
wake-up there will be an active input capture flag (and data) from that first valid edge which
occurred during STOP mode.
If STOP mode is exited by an external reset then no such input capture flag or data action takes
place even if there was a valid input capture edge (at one of the TCAP pins) during STOP mode.
5.7 Timer during WAIT mode
The timer system is not affected by WAIT mode and continues normal operation. Any valid timer
interrupt will wake-up the system.
5.8 Timer state diagrams
The relationships between the internal clock signals, the counter contents and the status of the
flag bits are shown in the following figures. It should be noted that the signals labelled ‘inter nal’
(processor clock, timer clocks and reset) are not available to the user.
MC68HC05B6 MOTOROLA
5-13
PROGRAMMABLE TIMER
5
Figure 5-2 Timer state timing diagram for reset
Figure 5-3 Timer state timing diagram for input capture
Internal
processor clock
Internal
reset
16-bit
counter
External reset
or end of POR
Internal
timer clocks
$FFFC $FFFD $FFFE $FFFF
Note:
The counter and timer control registers are the only ones affected by power-on or external reset.
T00
T01
T11
T10
Internal
processor clock
16-bit
counter $F123 $F124 $F125 $F126
Internal
timer clocks
T00
T01
T11
T10
Internal
capture latch
$F124$????
Input capture
register
Input capture
flag
Input
edge
}
}
}
}
Note:
If the input edge occurs in the shaded area from one timer state T10 to the next timer state T10, then
the input capture flag will be set during the next T11 state.
MOTOROLA
5-14 MC68HC05B6PROGRAMMABLE TIMER
5
Figure 5-4 Timer state timing diagram for output compare
Figure 5-5 Timer state timing diagram for timer overflow
Internal
processor clock
16-bit
counter $F456 $F457 $F458 $F459
Internal
timer clocks
T00
T01
T11
T10
$F457
CPU writes $F457
Output compare
flag and TCMP1,2
Note: 1 The CPU write to the compare registers may take place at any time, but a compare only occurs at timer state
T01. Thus a f our cycle diff erence may exist between the write to the compare register and the actual compare .
2The output compare flag is set at the timer state T11 that follows the comparison match ($F457 in this e xample).
Output compare
register
Compare register
latch
(Note 2)
(Note 1)
(Note 1)
Internal
processor clock
16-bit
counter $FFFF $0000 $0001 $0002
Internal
timer clocks
T00
T01
T11
T10
Note:
The timer overflow flag is set at timer state T11 (transition of counter from $FFFF to $0000). It is cleared
by a read of the timer status register dur ing the internal processor cloc k high time , followed by a read of the
counter low register.
Timer overflow
flag
MC68HC05B6 MOTOROLA
6-1
SERIAL COMMUNICATIONS INTERFACE
6
6
SERIAL COMMUNICATIONS INTERFACE
A full-duplex asynchronous serial communications interface (SCI) is provided with a standard
non-return-to-zero (NRZ) format and a variety of baud rates. The SCI tr ansmitter and receiv er are
functionally independent and have their own baud rate generator; however they share a common
baud rate prescaler and data format.
The serial data f ormat is standard mark/space (NRZ) and provides one start bit, eight or nine data
bits, and one stop bit.
The SCLK pin is the output of the transmitter clock. It outputs the transmitter data clock for
synchronous transmission (no clocks on start bit and stop bit, and a software option to send cloc k
on last data bit). This allows control of peripherals containing shift registers (e.g. LCD drivers).
Phase and polarity of these clocks are software programmable.
Any SCI bidirectional communication requires a two-wire system: receive data in (RDI) and
transmit data out (TDO).
‘Baud’ and ‘bit rate’ are used synonymously in the following description.
6.1 SCI two-wire system features
• Standard NRZ (mark/space) format
•Advanced error detection method with noise detection for noise duration of up to 1/16th bit time
• Full-duplex operation (simultaneous transmit and receive)
• 32 software selectable baud rates
• Different baud rates for transmit and receive; for each transmit baud rate, 8 possible receive
baud rates
• Software selectable word length (eight or nine bits)
• Separate transmitter and receiver enable bits
• Capable of being interrupt driven
• Transmitter clocks available without altering the regular transmitter or receiver functions
• Four separate enable bits for interrupt control
MOTOROLA
6-2 MC68HC05B6SERIAL COMMUNICATIONS INTERFACE
6
Figure 6-1 Serial communications interface block diagram
& & & &
+
+
Internal bus
SCI interrupt
Transmit Receive
TDO
pin RDI
Transmitter
control Receiver
control
clock
Clock extraction
phase and
polarity control
pin
Receiver
clock
Transmitter
Flag
control
data register data register
TIE
TCIE
RIE
ILIE
TE
RE
SBK
RWU
7
6
5
4
3
2
1
0
$000F
SCCR2
SCSR
$0010
SCCR1
$000E
TRDE TC RDRF IDLE OR NF FE
TE SBK
$0011
(See note) (See note)
R8 T8 M WAKE CPOL CPHA LBCL
012
4
3
6
5
7
7 6 5 2
34
1
SCLK
pin
Wake up
unit
Receive
data shift
register
Transmit
data shift
register
$0011
Note:
The serial communications data register (SCI SCDR) is controlled by the internal
R/W signal. It is the tr ansmit data register when wr itten to and the receiv e data
register when read.
7
MC68HC05B6 MOTOROLA
6-3
SERIAL COMMUNICATIONS INTERFACE
6
6.2 SCI receiver features
• Receiver wake-up function (idle line or address bit)
• Idle line detection
• Framing error detection
• Noise detection
• Overrun detection
• Receiver data register full flag
6.3 SCI transmitter features
• Transmit data register empty flag
• Transmit complete flag
• Send break
6.4 Functional description
A block diagram of the SCI is shown in Figure 6-1. Option bits in serial control register1 (SCCR1)
select the ‘wake-up’ method (W AKE bit) and data word length (M-bit) of the SCI. SCCR2 provides
control bits that individually enable the transmitter and receiver, enable system interrupts and
provide the w ake-up enable bit (RWU) and the send break code bit (SBK). Control bits in the baud
rate register (BAUD) allow the user to select one of 32 different baud rates for the transmitter and
receiver (see Section 6.11.5).
Data transmission is initiated by writing to the serial communications data register (SCDR).
Provided the transmitter is enabled, data stored in the SCDR is transferred to the transmit data
shift register. This transfer of data sets the transmit data register empty flag (TDRE) in the SCI
status register (SCSR) and generates an interrupt (if transmitter interrupts are enabled). The
transfer of data to the transmit data shift register is synchronized with the bit rate clock (see Figure
6-2). All data is transmitted least significant bit first. Upon completion of data transmission, the
transmission complete flag (TC) in the SCSR is set (pro vided no pending data, preamble or break
is to be sent) and an interrupt is generated (if the transmit complete interrupt is enabled). If the
transmitter is disabled, and the data, preamble or break (in the transmit data shift register) has
been sent, the TC bit will also be set. This will also generate an interrupt if the transmission
complete interrupt enable bit (TCIE) is set. If the transmitter is disab led during a transmission, the
character being transmitted will be completed before the transmitter gives up control of the
TDO pin.
MOTOROLA
6-4 MC68HC05B6SERIAL COMMUNICATIONS INTERFACE
6
When SCDR is read, it contains the last data byte received, provided that the receiv er is enabled.
The receive data register full flag bit (RDRF) in the SCSR is set to indicate that a data byte has
been transferred from the input serial shift register to the SCDR; this will cause an interrupt if the
receiver interrupt is enabled. The data transfer from the input serial shift register to the SCDR is
synchronized by the receiver bit rate clock. The OR (overrun), NF (noise), or FE (framing) error
flags in the SCSR may be set if data reception errors occurred.
An idle line interrupt is generated if the idle line interrupt is enabled and the IDLE bit (which detects
idle line transmission) in SCSR is set. This allows a receiver that is not in the wake-up mode to
detect the end of a message or the preamble of a new message, or to resynchronize with the
transmitter. A v alid character must be received before the idle line condition or the IDLE bit will not
be set and idle line interrupt will not be generated.
The SCP0 and SCP1 bits function as a prescaler for SCR0–SCR2 to generate the receiv er baud r ate
and for SCT0–SCT2 to generate the transmitter baud rate. Together , these eight bits provide multiple
transmitter/receiver rate combinations for a given crystal frequency (see Figure 6-2). This register
should only be written to while both the transmitter and receiver are disab led (TE=0, RE=0).
Figure 6-2 SCI rate generator division
SCP1 SPC0 SCT2 SCT1 SCT0 SCR2 SCR1 SCR0
Internal processor clock
SCP0 – SCP1
prescaler
rate control
( NP)
SCR0 – SCR2
receiver
( NR)
SCT0 – SCT2
transmitter
rate control
( NT)
16
Transmitter clock Receiver clock
rate control
76543210$000D
Baud rate register
Note:
There is a fixed rate divide-by-16 before the transmitter to compensate for the inherent divide-by-16 of the receiver (sampling).
This means that by loading the same value for both the transmitter and receiver baud rate selector, the same baud rates can be
obtained.
MC68HC05B6 MOTOROLA
6-5
SERIAL COMMUNICATIONS INTERFACE
6
6.5 Data format
Receive data or tr ansmit data is the serial data that is transferred to the internal data bus from the
receive data input pin (RDI) or from the internal bus to the transmit data output pin (TDO). The
non-return-to-zero (NRZ) data format shown in Figure 6-3 is used and must meet the following
criteria:
–The idle line is brought to a logic one state prior to transmission/reception of
a character.
– A start bit (logic zero) is used to indicate the start of a frame.
– The data is transmitted and received least significant bit first.
–A stop bit (logic one) is used to indicate the end of a frame. A fr ame consists
of a start bit, a character of eight or nine data bits, and a stop bit.
–A break is defined as the transmission or reception of a low (logic z ero) for at
least one complete frame time (10 zeros for 8-bit f ormat, 11 z eros for 9-bit).
6.6 Receiver wake-up operation
The receiver logic hardware also supports a receiver wake-up function which is intended for
systems having more than one receiver. With this function a transmitting device directs messages
to an individual receiver or group of receivers by passing addressing information as the initial
byte(s) of each message. The wake-up function allows receivers not addressed to remain in a
dormant state for the remainder of the unwanted message. This eliminates any further software
overhead to service the remaining characters of the unwanted message and thus improves
system performance.
The receiver is placed in wake-up mode by setting the receiver wake-up bit (RWU) in the SCCR2
register. While RWU is set, all of the receiver related status flags (RDRF, IDLE, OR, NF, and FE)
are inhibited (cannot become set). Note that the idle line detect function is inhibited while the R WU
bit is set. Although R WU may be cleared by a software write to SCCR2, it would be unusual to do
so. Normally RWU is set by software and is cleared automatically in hardware by one of the two
methods described below.
Figure 6-3 Data format
StartStop
Control bit M selects
8 or 9 bit data
Start
Idle line 0 1 2 3 4 5 6 7 8
0
MOTOROLA
6-6 MC68HC05B6SERIAL COMMUNICATIONS INTERFACE
6
6.6.1 Idle line wake-up
In idle line wake-up mode, a dor mant receiver wakes up as soon as the RDI line becomes idle.
Idle is defined as a continuous logic high level on the RDI line for ten (or eleven) full bit times.
Systems using this type of wake-up must provide at least one character time of idle between
messages to wake up sleeping receivers, but must not allow any idle time between characters
within a message.
6.6.2 Address mark wake-up
In address mark wake-up, the most significant bit (MSB) in a character is used to indicate whether
it is an address (1) or data (0) character. Sleeping receivers will wake up whenever an address
character is received. Systems using this method for wake-up would set the MSB of the first
character of each message and lea ve it clear for all other characters in the message . Idle periods
may be present within messages and no idle time is required between messages for this w ake-up
method.
6.7 Receive data in (RDI)
Receive data is the serial data that is applied through the input line and the SCI to the internal bus.
The receiver circuitry clocks the input at a rate equal to 16 times the baud rate. This time is referred
to as the RT rate in Figure 6-4 and as the receiver clock in Figure 6-2.
The receiver clock generator is controlled by the baud rate register, as shown in Figure 6-1 and
Figure 6-2; however, the SCI is synchronized by the start bit, independent of the transmitter.
Once a valid start bit is detected, the star t bit, each data bit and the stop bit are sampled three
times at R T intervals 8 R T, 9 RT and 10 R T (1 R T is the position where the bit is e xpected to start),
as shown in Figure 6-5. The value of the bit is determined by voting logic which takes the value of
the majority of the samples. A noise flag is set when all three samples on a valid start bit or data
bit or the stop bit do not agree.
6.8 Start bit detection
When the input (idle) line is detected low, it is tested for three more sample times (referred to as
the start edge v erification samples in Figure 6-4). If at least two of these three v erification samples
detect a logic zero, a valid start bit has been detected, otherwise the line is assumed to be idle. A
noise flag is set if one of the three verification samples detect a logic one, thus a valid star t bit
could be assumed with a set noise flag present.
MC68HC05B6 MOTOROLA
6-7
SERIAL COMMUNICATIONS INTERFACE
6
If there has been a framing error without detection of a break (10 zeros for 8 bit format or 11 zeros
for 9 bit format), the circuit continues to operate as if there actually was a stop bit, and the start
edge will be placed ar tificially. The last bit received in the data shift register is inverted to a logic
one, and the three logic one start qualifiers (shown in Figure 6-4) are forced into the sample shift
register during the interval when detection of a start bit is anticipated (see Figure 6-6); therefore,
the start bit will be accepted no sooner than it is anticipated.
Figure 6-4 SCI examples of start bit sampling technique
Figure 6-5 SCI sampling technique used on all bits
1 1 1 11 1 1111 1 0 0 0 0
1RT 2RT 3RT 5RT 7RT4RT 6RT 8RT
Start
qualifiers
Idle
Start edge
verification samples
16X internal sampling clock
RT clock edges for all three examples
Noise
Start
1 1 1 11 1 1110 1 0 0 0 0
1 1 1 11 1 1111 1 0 0 1 0
Start
Start
Noise
RDI
RDI
RDI
<
<
<
SamplesPresent bit Next bitPrevious bit
16RT 1RT 8RT 9RT 10RT 16RT 1RT
RDI
MOTOROLA
6-8 MC68HC05B6SERIAL COMMUNICATIONS INTERFACE
6
If the receiver detects that a break (RDRF = 1, FE = 1, receiver data register = $0000) produced
the framing error, the start bit will not be artificially induced and the receiver must actually detect
a logic one before the start bit can be recognised (see Figure 6-7).
6.9 Transmit data out (TDO)
Transmit data is the ser ial data from the internal data bus that is applied through the SCI to the
output line. Data format is as discussed in Section 6.5 and shown in Figure 6-3. The transmitter
generates a bit time by using a derivative of the RT clock, thus producing a transmission rate equal
to 1/16th that of the receiver sample clock (assuming the same baud rate is selected for both the
receiver and transmitter).
Figure 6-6 Artificial start following a framing error
Figure 6-7 SCI start bit following a break
Data Expected stop
Data samples
Artificial edge
Start bit
Data
RDI
Data Expected stop
Data samples
Start edge
Start bit
Data
RDI
a) Case 1: receive line low during artificial edge
b) Case 2: receive line high during expected start edge
Expected stop
Data samples
Detected as valid start edge
Start bit
RDI
Break
Start
qualifiers Start edge
verification
samples
MC68HC05B6 MOTOROLA
6-9
SERIAL COMMUNICATIONS INTERFACE
6
6.10 SCI synchronous transmission
The SCI transmitter allows the user to control a one way synchronous serial transmission. The
SCLK pin is the clock output of the SCI transmitter. No clocks are sent to that pin during start bit
and stop bit. Depending on the state of the LBCL bit (bit 0 of SCCR1), clocks will or will not be
activated during the last valid data bit (address mark). The CPOL bit (bit 2 of SCCR1) allows the
user to select the clock polarity, and the CPHA bit (bit 1 of SCCR1) allows the user to select the
phase of the external clock (see Figure 6-8, Figure 6-9 and Figure 6-10).
During idle, preamble and send break, the external SCLK clock is not activated.
These options allow the user to serially control peripherals which consist of shift registers, without
losing any functions of the SCI transmitter which can still talk to other SCI receiv ers. These options
do not affect the SCI receiver which is independent of the transmitter.
The SCLK pin works in conjunction with the TDO pin. When the SCI transmitter is disabled
(TE = 0), the SCLK and TDO pins go to the high impedance state.
Note:
The LBCL, CPOL and CPHA bits have to be selected before enabling the transmitter
to ensure that the clocks function correctly. These bits should not be changed while the
transmitter is enabled.
Figure 6-8 SCI example of synchronous and asynchronous transmission
RDI
TDO
SCLK
Output port
Data out
Data in
Data in
Clock
Enable
Asynchronous
MC68HC05B6
(e.g. Modem)
Synchronous
(e.g. shift register,
display driver, etc.)
MOTOROLA
6-10 MC68HC05B6SERIAL COMMUNICATIONS INTERFACE
6
6.11 SCI registers
The SCI system is configured and controlled by five registers: SCDR, SCCR1, SCCR2, SCSR,
and BAUD.
6.11.1 Serial communications data register (SCDR)
The SCDR is controlled by the internal R/W signal and performs two functions in the SCI. It acts
as the receive data register (RDR) when it is read and as the transmit data register (TDR) when
it is written. Figure 6-1 shows this register as two separate registers, RDR and TDR. The RDR
provides the interf ace from the receiv e shift register to the internal data bus and the TDR pro vides
the parallel interface from the internal data bus to the transmit shift register.
The receive data register is a read-only register containing the last byte of data received from the
shift register f or the internal data bus. The RDR full bit (RDRF) in the serial communications status
register is set to indicate that a byte has been transferred from the input serial shift register to the
SCDR. The transfer is synchronized with the receiver bit rate clock (from the receiver control) as
shown in Figure 6-1. All data is received with the least significant bit first.
The transmit data register (TDR) is a write-only register containing the next byte of data to be
applied to the transmit shift register from the internal data bus. As long as the transmitter is
enabled, data stored in the SCDR is tr ansferred to the tr ansmit shift register (after the current byte
in the shift register has been transmitted).
The transfer is synchronized with the transmitter bit rate clock (from the transmitter control) as
shown in Figure 6-1. All data is received with the least significant bit first.
6.11.2 Serial communications control register 1 (SCCR1)
The SCI control register 1 (SCCR1) contains control bits related to the nine data bit character
format, the receiver wake-up feature and the options to output the transmitter clocks for
synchronous transmissions.
Address bit 7 bit 6 bit 5 bit 4 bit 3 bit 2 bit 1 bit 0 State
on reset
SCI data (SCDR) $0011 0000 0000
Address bit 7 bit 6 bit 5 bit 4 bit 3 bit 2 bit 1 bit 0 State
on reset
SCI control 1 (SCCR1) $000E R8 T8 M WAKE CPOL CPHA LBCL Undefined
MC68HC05B6 MOTOROLA
6-11
SERIAL COMMUNICATIONS INTERFACE
6
R8 — Receive data bit 8
This read-only bit is the ninth serial data bit received when the SCI system is configured for nine
data bit operation (M = 1). The most significant bit (bit 8) of the received character is transferred
into this bit at the same time as the remaining eight bits (bits 0–7) are transferred from the serial
receive shifter to the SCI receive data register.
T8 — Transmit data bit 8
This read/write bit is the ninth data bit to be transmitted when the SCI system is configured f or nine
data bit operation (M = 1). When the eight low order bits (bits 0–7) of a transmit character are
transferred from the SCI data register to the serial transmit shift register, this bit (bit 8) is
transferred to the ninth bit position of the shifter.
M — Mode (select character format)
The read/write M-bit controls the character length for both the tr ansmitter and receiver at the same
time. The 9th data bit is most commonly used as an extra stop bit or in conjunction with the
‘address mark’ wake-up method. It can also be used as a parity bit (see Table 6-1).
1 (set) – Start bit, 8 data bits, 1 stop bit.
0 (clear) – Start bit, 9 data bits, 1 stop bit.
WAKE — Wake-up mode select
This bit allows the user to select the method for receiver wake-up. The WAKE bit can be read or
written to any time. See Table 6-1.
1 (set) – Wake-up on address mark.
0 (clear) – Wake-up on idle line.
Table 6-1 Method of receiver wake-up
WAKE M Method of receiver wake-up
0 x Detection of an idle line allows the next data type received to cause the receive
data register to fill and produce an RDRF flag.
1 0 Detection of a received one in the eighth data bit allows an RDRF flag and
associated error flags.
1 1 Detection of a received one in the ninth data bit allows an RDRF flag and
associated error flags.
x = Don’t care
MOTOROLA
6-12 MC68HC05B6SERIAL COMMUNICATIONS INTERFACE
6
CPOL – Clock polarity
This bit allows the user to select the polar ity of the clocks to be sent to the SCLK pin. It works in
conjunction with the CPHA bit to produce the desired clock-data relation (see Figure 6-9 and
Figure 6-10).
1 (set) – Steady high value at SCLK pin outside transmission window.
0 (clear) – Steady low value at SCLK pin outside transmission window.
This bit should not be manipulated while the transmitter is enabled.
CPHA – Clock phase
This bit allows the user to select the phase of the cloc ks to be sent to the SCLK pin. This bit works
in conjunction with the CPOL bit to produce the desired clock-data relation (see Figure 6-9 and
Figure 6-10).
1 (set) – SCLK clock line activated at beginning of data bit.
0 (clear) – SCLK clock line activated in middle of data bit.
This bit should not be manipulated while the transmitter is enabled.
Figure 6-9 SCI data clock timing diagram (M=0)
Idle or preceding
transmission
clock
Stop
Start
LSB
data
M = 0 (8 data bits) Idle or next
LBCL bit controls last data clock
transmission
clock
clock
clock
*
*
*
*
*
Start Stop
0123456MSB
7
(CPOL = 0, CPHA = 0)
(CPOL = 0, CPHA = 1)
(CPOL = 1, CPHA = 0)
(CPOL = 1, CPHA = 1)
MC68HC05B6 MOTOROLA
6-13
SERIAL COMMUNICATIONS INTERFACE
6
LBCL – Last bit clock
This bit allows the user to select whether the clock associated with the last data bit transmitted
(MSB) has to be output to the SCLK pin. The clock of the last data bit is output to the SCLK pin if
the LBCL bit is a logic one, and is not output if it is a logic zero.
The last bit is the 8th or 9th data bit transmitted depending on the 8 or 9 bit format selected by
M-bit (seeTable 6-2).
This bit should not be manipulated while the transmitter is enabled.
Figure 6-10 SCI data clock timing diagram (M=1)
Table 6-2 SCI clock on SCLK pin
Data format M-bit LBCL bit Number of clocks on
SCLK pin
8 bit 0 0 7
8 bit 0 1 8
9 bit 1 0 8
9 bit 1 1 9
Idle or preceding
transmission
clock
StopStart
LSB
data
M = 1 (9 data bits) Idle or next
LBCL bit controls last data clock
transmission
clock
clock
clock
*
*
*
*
Start Stop
0123456MSB
7
*
8
(CPOL = 0, CPHA = 0)
(CPOL = 0, CPHA = 1)
(CPOL = 1, CPHA = 0)
(CPOL = 1, CPHA = 1)
MOTOROLA
6-14 MC68HC05B6SERIAL COMMUNICATIONS INTERFACE
6
6.11.3 Serial communications control register 2 (SCCR2)
The SCI control register 2 (SCCR2) provides the control bits that enable/disable individual SCI
functions.
TIE — Transmit interrupt enable
1 (set) – TDRE interrupts enabled.
0 (clear) – TDRE interrupts disabled.
TCIE — Transmit complete interrupt enable
1 (set) – TC interrupts enabled.
0 (clear) – TC interrupts disabled.
RIE — Receiver interrupt enable
1 (set) – RDRF and OR interrupts enabled.
0 (clear) – RDRF and OR interrupts disabled.
ILIE — Idle line interrupt enable
1 (set) – IDLE interrupts enabled.
0 (clear) – IDLE interrupts disabled.
TE — Transmitter enable
When the transmit enable bit is set, the transmit shift register output is applied to the TDO line and
the corresponding clocks are applied to the SCLK pin. Depending on the state of control bit M
(SCCR1), a preamble of 10 (M = 0) or 11 (M = 1) consecutive ones is transmitted when software
sets the TE bit from a cleared state.
If a transmission is in progress and a zero is written to TE, the transmitter will wait until after the
present byte has been transmitted before placing the TDO and the SCLK pin in the idle, high
impedance state.
If the TE bit has been written to a zero and then set to a one before the current b yte is transmitted,
the transmitter will wait for that byte to be transmitted and will then initiate transmission of a new
preamble. After this latest transmission, and provided the TDRE bit is set (no new data to
transmit), the line remains idle (driven high while TE = 1); otherwise , normal transmission occurs.
This function allows the user to neatly terminate a transmission sequence.
Address bit 7 bit 6 bit 5 bit 4 bit 3 bit 2 bit 1 bit 0 State
on reset
SCI control (SCCR2) $000F TIE TCIE RIE ILIE TE RE RWU SBK 0000 0000
MC68HC05B6 MOTOROLA
6-15
SERIAL COMMUNICATIONS INTERFACE
6
After loading the last byte in the serial communications data register and receiving the TDRE flag,
the user should clear TE. Transmission of the last byte will then be completed and the line will go
idle.
1 (set) – Transmitter enabled.
0 (clear) – Transmitter disabled.
RE — Receiver enable
1 (set) – Receiver enabled.
0 (clear) – Receiver disabled.
When RE is clear (receiver disabled) all the status bits associated with the receiver (RDRF, IDLE,
OR, NF and FE) are inhibited.
RWU — Receiver wake-up
When the receiver wake-up bit is set b y the user software, it puts the receiv er to sleep and enables
the wake-up function. The type of wake-up mode for the receiver is determined by the WAKE bit
discussed above (in the SCCR1). When the RWU bit is set, no status flags will be set. Flags which
were set previously will not be cleared when RWU is set.
If the W AKE bit is cleared, R WU is cleared b y the SCI logic after receiving 10 (M = 0) or 11 (M =1)
consecutive ones. Under these conditions, RWU cannot be set if the line is idle. If the WAKE bit
is set, RWU is cleared after receiving an address bit. The RDRF flag will then be set and the
address byte stored in the receiver data register.
SBK — Send break
If the send break bit is toggled set and cleared, the transmitter sends 10 (M = 0) or 11 (M = 1)
zeros and then reverts to idle sending data. If SBK remains set, the transmitter will continually
send whole blocks of zeros (sets of 10 or 11) until cleared. At the completion of the break code,
the transmitter sends at least one high bit to guarantee recognition of a valid start bit.
MOTOROLA
6-16 MC68HC05B6SERIAL COMMUNICATIONS INTERFACE
6
6.11.4 Serial communications status register (SCSR)
The serial communications status register (SCSR) provides inputs to the interrupt logic circuits for
generation of the SCI system interrupt. In addition, a noise flag bit and a framing error bit are also
contained in the SCSR.
TDRE — Transmit data register empty flag
This bit is set when the contents of the transmit data register are transferred to the serial shift
register. New data will not be transmitted unless the SCSR register is read before writing to the
transmit data register to clear the TDRE flag.
If the TDRE bit is clear , this indicates that the transfer has not yet occurred and a write to the serial
communications data register will overwrite the previous value. The TDRE bit is cleared by
accessing the serial communications status register (with TDRE set) followed by writing to the
serial communications data register.
TC — Transmit complete flag
This bit is set to indicate that the SCI transmitter has no meaningful information to transmit (no
data in shifter, no preamble, no break). When TC is set the serial line will go idle (continuous
MARK). The TC bit is cleared by accessing the serial communications data register (with TC set)
followed by writing to the serial communications data register. It does not inhibit the transmitter
function in any way.
RDRF — Receive data register full flag
This bit is set when the contents of the receiver serial shift register are transferred to the receiver
data register.
If multiple errors are detected in any one received word, the NF and RDRF bits will be aff ected as
appropriate during the same clock cycle . The RDRF bit is cleared when the serial communications
status register is accessed (with RDRF set) f ollowed by a read of the serial communications data
register.
IDLE — Idle line detected flag
This bit is set when a receiver idle line is detected (the receipt of a minimum of ten/eleven
consecutive “1”s). This bit will not be set by the idle line condition when the RWU bit is set. This
allows a receiver that is not in the wake-up mode to detect the end of a message, detect the
preamble of a new message or resynchronize with the transmitter. The IDLE bit is cleared by
accessing the serial communications status register (with IDLE set) followed by a read of the serial
communications data register . Once cleared, IDLE will not be set again until after RDRF has been
set, (i.e. until after the line has been active and becomes idle again).
Address bit 7 bit 6 bit 5 bit 4 bit 3 bit 2 bit 1 bit 0 State
on reset
SCI status (SCSR) $0010 TDRE TC RDRF IDLE OR NF FE 1100 000u
MC68HC05B6 MOTOROLA
6-17
SERIAL COMMUNICATIONS INTERFACE
6
OR — Overrun error flag
This bit is set when a new byte is ready to be transferred from the receiver shift register to the
receiver data register and the receive data register is already full (RDRF bit is set). Data transfer
is inhibited until the RDRF bit is cleared. Data in the serial communications data register is valid
in this case, but additional data received during an overrun condition (including the byte causing
the overrun) will be lost.
The OR bit is cleared when the serial communications status register is accessed (with OR set)
followed by a read of the serial communications data register.
NF — Noise error flag
This bit is set if there is noise on a ‘valid’ start bit, any of the data bits or on the stop bit. The NF
bit is not set by noise on the idle line nor by invalid start bits. If there is noise, the NF bit is not set
until the RDRF flag is set. Each data bit is sampled three times as described in Section 6.7.
The NF bit represents the status of the byte in the serial communications data register. For the
byte being received (shifted in) there will be also a ‘working’ noise flag, the value of which will be
transferred to the NF bit when the serial data is loaded into the serial communications data
register. The NF bit does not generate an interrupt because the RDRF bit gets set with NF and
can be used to generate the interrupt.
The NF bit is cleared when the serial communications status register is accessed (with NF set)
followed by a read of the serial communications data register.
FE — Framing error flag
This bit is set when the word boundaries in the bit stream are not synchronized with the receiver
bit counter (generated by the reception of a logic z ero bit where a stop bit w as expected). The FE
bit reflects the status of the byte in the receive data register and the transfer from the receive
shifter to the receive data register is inhibited by an overrun. The FE bit is set during the same
cycle as the RDRF bit but does not get set in the case of an overrun (OR). The framing error flag
inhibits further transfer of data into the receive data register until it is cleared.
The FE bit is cleared when the serial communications status register is accessed (with FE set)
followed by a read of the serial communications data register.
MOTOROLA
6-18 MC68HC05B6SERIAL COMMUNICATIONS INTERFACE
6
6.11.5 Baud rate register (BAUD)
The baud rate register provides the means to select two different or equivalent baud rates for the
transmitter and receiver.
SCP1, SCP0 — Serial prescaler select bits
These read/write bits deter mine the prescale factor, NP, by which the internal processor clock is
divided before it is applied to the transmitter and receiver rate control dividers, NT and NR. This
common prescaled output is used as the input to a divider that is controlled by the SCR0–SCR2
bits for the SCI receiver, and by the SCT0–SCT2 bits for the transmitter.
SCT2, SCT1,SCT0 — SCI rate select bits (transmitter)
These three read/write bits select the baud rates for the transmitter. The prescaler output is
divided by the factors shown in Table 6-4.
Address bit 7 bit 6 bit 5 bit 4 bit 3 bit 2 bit 1 bit 0 State
on reset
SCI baud rate (BAUD) $000D SCP1 SCP0 SCT2 SCT1 SCT0 SCR2 SCR1 SCR0 00uu uuuu
Table 6-3 First prescaler stage
SCP1 SCP0 Prescaler
division ratio (NP)
0 0 1
0 1 3
1 0 4
1 1 13
Table 6-4 Second prescaler stage (transmitter)
SCT2 SCT1 SCT0 Transmitter
division ratio (NT)
0 0 0 1
0 0 1 2
0 1 0 4
0 1 1 8
1 0 0 16
1 0 1 32
1 1 0 64
1 1 1 128
MC68HC05B6 MOTOROLA
6-19
SERIAL COMMUNICATIONS INTERFACE
6
SCR2, SCR1, SCR0 — SCI rate select bits (receiver)
These three read/write bits select the baud rates for the receiver. The prescaler output described
above is divided by the factors shown in Table 6-5.
The following equations are used to calculate the receiver and transmitter baud rates:
where:
NP = prescaler divide ratio
NT = transmitter baud rate divide ratio
NR = receiver baud rate divide ratio
baudTx = transmitter baud rate
baudRx = receiver baud rate
fOSC = oscillator frequency
6.12 Baud rate selection
The flexibility of the baud rate generator allows many different baud rates to be selected. A
particular baud rate may be generated in several ways by manipulating the various prescaler and
division ratio bits. Table 6-6 shows the baud rates that can be achieved, for five typical crystal
frequencies. These are effectively the highest baud rates which can be achieved using a given
crystal.
Table 6-5 Second prescaler stage (receiver)
SCR2 SCR1 SCR0 Receiver
division ratio (NR)
0 0 0 1
0 0 1 2
0 1 0 4
0 1 1 8
1 0 0 16
1 0 1 32
1 1 0 64
1 1 1 128
baudTx fosc
32 NP N
T• •
----------------------------------
=
baudRx fosc
32 NP NR• •
--------------------------------
---
=
MOTOROLA
6-20 MC68HC05B6SERIAL COMMUNICATIONS INTERFACE
6
Note:
The examples shown above do not apply when the part is operating in slow mode (see
Section 2.4.3).
Table 6-6 SCI baud rate selection
Crystal frequency – fosc (MHz)
SCP1 SCP0 SCT/R2 SCT/R1 SCT/R0 NP NT/NR 4.194304 4.00 2.4576 2.00 1.8432
0 0 0 0 0 1 1 131072 125000 76800 62500 57600
0 0 0 0 1 1 2 65536 62500 38400 31250 28800
0 0 0 1 0 1 4 32768 31250 19200 15625 14400
0 0 0 1 1 1 8 16384 15625 9600 7813 7200
0 0 1 0 0 1 16 8192 7813 4800 3906 3600
0 0 1 0 1 1 32 4096 3906 2400 1953 1800
0 0 1 1 0 1 64 2048 1953 1200 977 900
0 0 1 1 1 1 128 1024 977 600 488 450
0 1 0 0 0 3 1 43691 41667 25600 20833 19200
0 1 0 0 1 3 2 21845 20833 12800 10417 9600
0 1 0 1 0 3 4 10923 10417 6400 5208 4800
0 1 0 1 1 3 8 5461 5208 3200 2604 2400
0 1 1 0 0 3 16 2731 2604 1600 1302 1200
0 1 1 0 1 3 32 1365 1302 800 651 600
0 1 1 1 0 3 64 683 651 400 326 300
0 1 1 1 1 3 128 341 326 200 163 150
1 0 0 0 0 4 1 32768 31250 19200 15625 14400
1 0 0 0 1 4 2 16384 15625 9600 7813 7200
1 0 0 1 0 4 4 8192 7813 4800 3906 3600
1 0 0 1 1 4 8 4096 3906 2400 1953 1800
1 0 1 0 0 4 16 2048 1953 1200 977 900
1 0 1 0 1 4 32 1024 977 600 488 450
1 0 1 1 0 4 64 512 488 300 244 225
1 0 1 1 1 4 128 256 244 150 122 113
1 1 0 0 0 13 1 10082 9615 5908 4808 4431
1 1 0 0 1 13 2 5041 4808 2954 2404 2215
1 1 0 1 0 13 4 2521 2404 1477 1202 1108
1 1 0 1 1 13 8 1260 1202 738 601 554
1 1 1 0 0 13 16 630 601 369 300 277
1 1 1 0 1 13 32 315 300 185 150 138
1 1 1 1 0 13 64 158 150 92 75 69
1 1 1 1 1 13 128 79 75 46 38 35
MC68HC05B6 MOTOROLA
6-21
SERIAL COMMUNICATIONS INTERFACE
6
6.13 SCI during STOP mode
When the MCU enters STOP mode, the baud rate generator driving the receiver and transmitter
is shut down. This stops all SCI activity. Both the receiver and the transmitter are unable to
operate.
If the STOP instruction is executed during a transmitter transfer, that transfer is halted. When
STOP mode is exited as a result of an external interrupt, that particular transmission resumes.
If the receiver is receiving data when the STOP instruction is executed, received data sampling is
stopped (baud generator stops) and the rest of the data is lost.
Warning: For the above reasons, all SCI transactions should be in the idle state when the ST OP
instruction is executed.
6.14 SCI during WAIT mode
The SCI system is not affected by WAIT mode and continues normal operation. Any valid SCI
interrupt will wake-up the system. If required, the SCI system can be disabled prior to entering
WAIT mode by writing a zero to the transmitter and receiver enable bits in the serial
communication control register 2 at $000F. This action will result in a reduction of power
consumption during WAIT mode.
MOTOROLA
6-22 MC68HC05B6SERIAL COMMUNICATIONS INTERFACE
THIS PAGE INTENTIONALLY LEFT BLANK
6
MC68HC05B6 MOTOROLA
7-1
PULSE LENGTH D/A CONVERTERS
7
7
PULSE LENGTH D/A CONVERTERS
The pulse length D/A converter (PLM) system works in conjunction with the timer to execute two
8-bit D/A conversions, with a choice of two repetition rates. (See Figure 7-1.)
Figure 7-1 PLM system block diagram
PLMA
register
PLMB
‘A’ register
buffer ‘B’ register
‘A’
comparator ‘B’
Latch
Zero detector
SFA bit
SFB
D/A
pin
Timer bus From timer
Data bus
8
16
multiplexer
‘A’ ‘B’
buffer
register
comparator
multiplexer
PLMA
PLMB
D/A R
S
bit
Zero detector
8
16
8 8
pin
Latch
R
S
MOTOROLA
7-2 MC68HC05B6PULSE LENGTH D/A CONVERTERS
7
The D/A converter has two data registers associated with it, PLMA and PLMB.
This is a dual 8-bit resolution D/A converter associated with two output pins (PLMA and PLMB).
The outputs are pulse length modulated signals whose duty cycle ratio may be modified. These
signals can be used directly as PLMs, or the filtered average may be used as general purpose
analog outputs.
The longest repetition period is 4096 times the programmable timer clock period (CPU clock
multiplied by four), and the shor test repetition per iod is 256 times the programmable timer clock
period (the repetition rate frequencies for a 4 MHz crystal are 122 Hz and 1953 Hz respectively).
Registers PLMA ($0A) and PLMB ($0B) are associated with the pulse length values of the two
counters. A value of $00 loaded into these registers results in a continuously low output on the
corresponding D/A output pin. A value of $80 results in a 50% duty cycle output, and so on, to the
maximum value $FF corresponding to an output which is at ‘1’ f or 255/256 of the cycle . When the
MCU makes a wr ite to register PLMA or PLMB the new value will only be picked up by the D/A
converters at the end of a complete cycle of conversion. This results in a monotonic change of the
DC component at the output without overshoots or vicious starts (a vicious start is an output which
gives totally erroneous PLM during the period immediately following an update of the PLM D/A
registers). This feature is achieved by double buffering of the PLM D/A registers. Examples of
PWM output waveforms are shown in Figure 7-2.
Address bit 7 bit 6 bit 5 bit 4 bit 3 bit 2 bit 1 bit 0 State
on reset
Pulse length modulation A (PLMA) $000A 0000 0000
Pulse length modulation B (PLMB) $000B 0000 0000
Figure 7-2 PLM output waveform examples
256 T
255 T
128 T
T
$80
$FF
T = 4 CPU clocks in fast mode and 64 CPU clocks in slow mode
128 T
T
$00
$01
255 T
MC68HC05B6 MOTOROLA
7-3
PULSE LENGTH D/A CONVERTERS
7
Note:
Since the PLM system uses the timer counter, PLM results will be affected while resetting
the timer counter. Both D/A registers are reset to $00 during power-on or external reset.
WAIT mode does not affect the output waveform of the D/A converters.
7.1 Miscellaneous register
SFA — Slow or fast mode selection for PLMA
This bit allows the user to select the slow or fast mode of the PLMA pulse length modulation
output.
1 (set) – Slow mode PLMA (4096 x timer clock period).
0 (clear) – Fast mode PLMA (256 x timer clock period).
SFB — Slow or fast mode selection for PLMB
This bit allows the user to select the slow or fast mode of the PLMB pulse length modulation
output.
1 (set) – Slow mode PLMB (4096 x timer clock period).
0 (clear) – Fast mode PLMB (256 x timer clock period).
The highest speed of the PLM system corresponds to the frequency of the TOF bit being set,
multiplied by 256. The lowest speed of the PLM system corresponds to the frequency of the TOF
bit being set, multiplied by 16. Because the SFA bit and SFB bit are not double buffered, it is
mandatory to set them to the desired values before writing to the PLM registers; not doing so could
temporarily give incorrect values at the PLM outputs.
SM — Slow mode
1 (set) – The system runs at a bus speed 16 times lower than normal
(fOSC/32). SLOW mode affects all sections of the device, including
SCI, A/D and timer.
0 (clear) – The system runs at normal bus speed (fOSC/2).
Address bit 7 bit 6 bit 5 bit 4 bit 3 bit 2 bit 1 bit 0 State
on reset
Miscellaneous $000C POR INTP INTN INTE SFA SFB SM WDOG ?001 000?
MOTOROLA
7-4 MC68HC05B6PULSE LENGTH D/A CONVERTERS
7
The SM bit is cleared by external or power-on reset. The SM bit is automatically cleared when
entering STOP mode.
Note:
The bits that are shown shaded in the above representation are explained individually
in the relevant sections of this manual. The complete register plus an explanation of
each bit can be found in Section 3.8
7.2 PLM clock selection
The slow/fast mode of the PLM D/A converters is selected by bits 1, 2, and 3 of the miscellaneous
register at address $000C (SFA bit for PLMA and SFB bit for PLMB). The slow/fast mode has no
effect on the D/A converters’ 8-bit resolution (see Figure 7-3).
7.3 PLM during STOP mode
On entering STOP mode, the PLM outputs remain at their par ticular level. When STOP mode is
exited by an interrupt, the PLM systems resume regular operation. If STOP mode is exited by
power-on or external reset the registers values are forced to $00.
7.4 PLM during WAIT mode
The PLM system is not affected by WAIT mode and continues normal operation.
Figure 7-3 PLM clock selection
fOSC 2
32
SM bit = 0
SM bit = 1
4 x4096
x256
SF bit = 1
SF bit = 0
Timer
clock PLM
clock
Bus
frequency (fOP)
MC68HC05B6 MOTOROLA
8-1
ANALOG TO DIGITAL CONVERTER
8
8
ANALOG TO DIGITAL CONVERTER
The analog to digital converter system consists of a single 8-bit successive approximation
converter and a sixteen channel multiplexer. Eight of the channels are connected to the
PD0/AN0 – PD7/AN7 pins of the MC68HC05B6 and the other eight channels are dedicated to
internal reference points for test functions. The channel input pins do not ha ve any internal output
driver circuitry connected to them because such circuitry would load the analog input signals due
to output buffer leakage current. There is one 8-bit result data register (address $08) and one 8-bit
status/control register (address $09).
The A/D converter is ratiometric and two dedicated pins, VRH and VRL, are used to supply the
reference voltage levels for all analog inputs. These pins are used in preference to the system
power supply lines because any voltage drops in the bonding wires of the heavily loaded supply
pins could degrade the accuracy of the A/D conversion. An input voltage equal to or greater than
VRH converts to $FF (full scale) with no overflow indication and an input voltage equal to VRL
converts to $00.
The A/D converter can operate from either the bus clock or an internal RC type oscillator. The
internal RC type oscillator is activated by the ADRC bit in the A/D status/control register (ADSTAT)
and can be used to giv e a sufficiently high clock rate to the A/D converter when the bus speed is too
low to provide accurate results. When the A/D converter is not being used it can be disconnected,
by clearing the ADON bit in the ADSTAT register, in order to save power (see Section 8.2.3).
For further information on A/D converter operation please refer to the M68HC11 Reference
Manual — M68HC11RM/AD.
8.1 A/D converter operation
The A/D converter consists of an analog multiplexer, an 8-bit digital to analog converter capacitor
array, a comparator and a successive approximation register (SAR) (see Figure 8-1).
There are eleven options that can be selected by the multiplexer; AN0–AN7, VRH, (VRH+VRL)/2
or VRL. Selection is done via the CHx bits in the ADSTAT register (see Section 8.2.3). AN0–AN7
are the only input points for A/D conversion operations; the others are reference points that can
be used for test purposes.
MOTOROLA
8-2 MC68HC05B6ANALOG TO DIGITAL CONVERTER
8
The A/D reference input (AN0–AN7) is applied to a precision internal D/A converter. Control logic
drives this D/A converter and the analog output is successively compared with the analog input
sampled at the beginning of the conversion. The conversion is monotonic with no missing codes.
The result of each successive comparison is stored in the SAR and, when the conversion is
complete, the contents of the SAR are transferred to the read-only result data register ($08), and
the conversion complete flag, COCO, is set in the A/D status/control register ($09).
Warning: Any write to the A/D status/control register will abor t the current conversion, reset the
conversion complete flag and start a new conversion on the selected channel.
At power-on or e xternal reset, both the ADRC and ADON bits are cleared; thus the A/D is disabled.
Figure 8-1 A/D converter block diagram
AN0
VRH
(VRH+VRL)/2
VRL
Analog MUX
A/D result register (ADDATA) $08
8-bit capacitive DAC
with sample and hold
VRH
VRL
Result
A/D status/control register (ADSTAT)$09
(Channel assignment)
COCO
ADRCADON0CH3CH2CH1CH0
AN1
AN2
AN3
AN4
AN5
AN6
AN7
Successive approximation
register (SAR) and control
MC68HC05B6 MOTOROLA
8-3
ANALOG TO DIGITAL CONVERTER
8
8.2 A/D registers
8.2.1 Port D data register (PORTD)
Port D is an input-only por t which routes the eight analog inputs to the A/D converter. When the
A/D converter is disabled, the pins are configured as standard input-only port pins, which can be
read via the port D data register.
Note:
When the A/D function is enabled, pins PD0–PD7 will act as analog inputs . Using a pin
or pins as A/D inputs does not aff ect the ability to read port D as static inputs; however,
reading port D during an A/D conversion sequence may inject noise on the analog
inputs and result in reduced accuracy of the A/D result.
Performing a digital read of por t D with levels other than VDD or VSS on the pins will
result in greater power dissipation dur ing the read cycle, and may give unpredictable
results on the corresponding port D pins.
8.2.2 A/D result data register (ADDATA)
ADDATA is a read-only register which is used to store the results of A/D conversions. Each result
is loaded into the register from the SAR and the conversion complete flag, COCO , in the ADSTAT
register is set.
Address bit 7 bit 6 bit 5 bit 4 bit 3 bit 2 bit 1 bit 0 State
on reset
Port D data (PORTD) $0003 PD7 PD6 PD5 PD4 PD3 PD2 PD1 PD0 Undefined
Address bit 7 bit 6 bit 5 bit 4 bit 3 bit 2 bit 1 bit 0 State
on reset
A/D data (ADDATA) $0008 0000 0000
MOTOROLA
8-4 MC68HC05B6ANALOG TO DIGITAL CONVERTER
8
8.2.3 A/D status/control register (ADSTAT)
COCO — Conversion complete flag
1 (set) – COCO is set each time a conversion is complete, allowing the new
result to be read from the A/D result data register ($08). The
converter then starts a new conversion.
0 (clear) – COCO is cleared by reading the result data register or writing to the
status/control register.
Reset clears the COCO flag.
ADRC — A/D RC oscillator control
The ADRC bit allows the user to control the A/D RC oscillator, which is used to provide a
sufficiently high clock rate to the A/D to ensure accuracy when the chip is running at low speeds.
1 (set) –When the ADRC bit is set, the A/D RC oscillator is turned on and, if
ADON is set, the A/D runs from the RC oscillator clock. See Table 8-1.
0 (clear) – When the ADRC bit is cleared, the A/D RC oscillator is turned-off
and, if ADON is set, the A/D runs from the CPU clock.
When the A/D RC oscillator is turned on, it takes a time tADRC to stabilize (see Table 11-7 and
Table 11-8). During this time A/D conversion results may be inaccurate.
Note:
If the MCU bus clock falls below 1MHz, the A/D RC oscillator should be switched on.
Power-on or external reset clears the ADRC bit.
Address bit 7 bit 6 bit 5 bit 4 bit 3 bit 2 bit 1 bit 0 State
on reset
A/D status/control (ADSTAT) $0009 COCO ADRC ADON 0 CH3 CH2 CH1 CH0 0000 0000
Table 8-1 A/D clock selection
ADRC ADON RC
oscillator A/D
converter Comments
0 0 OFF OFF A/D switched off.
0 1 OFF ON A/D using CPU clock.
1 0 ON OFF Allows the RC oscillator to stabilize.
1 1 ON ON A/D using RC oscillator clock.
MC68HC05B6 MOTOROLA
8-5
ANALOG TO DIGITAL CONVERTER
8
ADON — A/D converter on
The ADON bit allows the user to enable/disable the A/D converter.
1 (set) – A/D converter is switched on.
0 (clear) – A/D converter is switched off.
When the A/D converter is switched on, it takes a time tADON for the current sources to stabilize
(see Table 11-7 and Table 11-8). During this time A/D conversion results may be inaccurate.
Power-on or external reset will clear the ADON bit, thus disabling the A/D converter.
CH3–CH0 — A/D channels 3, 2, 1 and 0
The CH3–CH0 bits allow the user to determine which channel of the A/D converter multiplexer is
selected. See Table 8-2 for channel selection.
Reset clears the CH0–CH3 bits.
8.3 A/D converter during STOP mode
When the MCU enters ST OP mode with the A/D converter turned on, the A/D clocks are stopped
and the A/D converter is disabled for the duration of STOP mode, including the 4064 cycles
start-up time. If the A/D RC oscillator is in operation it will also be disabled.
Table 8-2 A/D channel assignment
CH3 CH2 CH1 CH0 Channel selected
0 0 0 0 AN0
0 0 0 1 AN1
0 0 1 0 AN2
0 0 1 1 AN3
0 1 0 0 AN4
0 1 0 1 AN5
0 1 1 0 AN6
0 1 1 1 AN7
1 0 0 0 VRH pin (high)
1 0 0 1 (VRH + VRL) / 2
1 0 1 0 VRL pin (low)
1 0 1 1 VRL pin (low)
1 1 0 0 VRL pin (low)
1 1 0 1 VRL pin (low)
1 1 1 0 VRL pin (low)
1 1 1 1 VRL pin (low)
MOTOROLA
8-6 MC68HC05B6ANALOG TO DIGITAL CONVERTER
8
8.4 A/D converter during WAIT mode
The A/D converter is not affected by WAIT mode and continues normal operation.
In order to reduce power consumption the A/D converter can be disconnected, under software
control using the ADON bit and the ADRC bit in the A/D status/control register at $0009, before
entering WAIT mode.
8.5 Port D analog input
The external analog voltage value to be processed by the A/D converter is sampled on an internal
capacitor through a resistive path, provided by input-selection switches and a sampling aperture
time switch, as shown in Figure 8-2. Sampling time is limited to 12 bus clock cycles. After
sampling, the analog value is stored on the capacitor and held until the end of con version. During
this hold time, the analog input is disconnected from the internal A/D system and the external
voltage source sees a high impedance input.
The equivalent analog input during sampling is an RC low-pass filter with a minimum resistance
of 50 k and a capacitance of at least 10pF. It should be noted that these are typical values
measured at room temperature.
Figure 8-2 Electrical model of an A/D input pin
Analog
input
pin
Input protection device
VRL
< 2pF + ~20V
- ~0.7V
400 nA
junction
leakage
50k
10pF
DAC
capacitance
Note:
The analog switch is closed during the 12 cycle sample time only.
MC68HC05B6 MOTOROLA
9-1
RESETS AND INTERRUPTS
9
9
RESETS AND INTERRUPTS
9.1 Resets
The MC68HC05B6 can be reset in three ways: by the initial power-on reset function, by an active
low input to the
RESET pin or by a computer operating proper ly (COP) watchdog reset. Any of
these resets will cause the program to go to its starting address, specified by the contents of
memory locations $1FFE and $1FFF, and cause the interrupt mask bit in the condition code
register to be set.
Figure 9-1 Reset timing diagram
VDD
RESET
1FFF1FFE
1FFE
1FFE
New
1FFF1FFE1FFE1FFE PC
OSC1
New
PC
Internal
Internal
processor clock
1FFE
Op
code
New
PCL
New
PCH
tVDDR
Op
code
New
PCL
New
PCH
address bus
Internal
data bus
tOXOV
tCYC
tPORL
1FFE
Program
execution
begins
Program
execution
begins
tRL(or tDOGL)
(Internal power-on reset) (External hardware reset)
VDD threshold (1-2V typical)
Reset sequence Reset sequence
MOTOROLA
9-2 MC68HC05B6RESETS AND INTERRUPTS
9
9.1.1 Power-on reset
A power-on reset occurs when a positive transition is detected on VDD. The power-on reset
function is strictly for power turn-on conditions and should not be used to detect drops in the power
supply voltage. The power-on circuitry provides a stabilization delay (tPORL) from when the
oscillator becomes active. If the external RESET pin is low at the end of this delay then the
processor remains in the reset state until RESET goes high. The user must ensure that the voltage
on VDD has risen to a point where the MCU can operate properly by the time tPORL has elapsed.
If there is doubt, the e xternal RESET pin should remain low until the voltage on VDD has reached
the specified minimum operating voltage. This may be accomplished by connecting an external
RC circuit to this pin to generate a power-on reset (POR). In this case, the time constant must be
great enough to allow the oscillator circuit to stabilize.
During power-on reset, the RESET pin is driven low during a tPORL delay start-up sequence. tPORL is
defined by a user specified mask option to be either 16 cycles or 4064 cycles (see Section 1.2).
A software distinction between a power-on reset and an external reset can be made using the
POR bit in the miscellaneous register (see Section 9.1.2).
9.1.2 Miscellaneous register
POR — Power-on reset bit
This bit is set each time the device is powered on. Therefore, the state of the POR bit allows the
user to make a software distinction between a power-on and an external reset. This bit cannot be
set by software and is cleared by writing it to zero.
1 (set) – A power-on reset has occurred.
0 (clear) – No power-on reset has occurred.
Note:
The bits shown shaded in the above representation are explained individually in the
relevant sections of this manual. The complete register plus an explanation of each bit
can be found in Section 3.8.
(1) The POR bit is set each time there is a power-on reset.
(2) The state of the WDOG bit after reset is dependent on the mask option selected; 1=watchdog enabled, 0=watchdog disabled.
Address bit 7 bit 6 bit 5 bit 4 bit 3 bit 2 bit 1 bit 0 State
on reset
Miscellaneous $000C POR(1)
INTP INTN INTE SFA SFB SM WDOG(2) ?001 000?
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9-3
RESETS AND INTERRUPTS
9
9.1.3 RESET pin
When the oscillator is running in a stable condition, the MCU is reset when a logic zero is applied
to theRESET input for a minimum period of 1.5 machine cycles (tCYC). An internal Schmitt Trigger
is used to improve noise immunity on this pin. When the RESET pin goes high, the MCU will
resume operation on the following cycle. When a reset condition occurs inter nally, i.e. from POR
or the COP watchdog, the RESET pin provides an active-low open drain output signal which may
be used to reset external hardware. Current limitation to protect the pull-down device is provided
in case an RC type external reset circuit is used.
9.1.4 Computer operating properly (COP) watchdog reset
The watchdog counter system consists of a divide-by-8 counter, preceded by a fixed divide-by-4
and a fixed divide-by-256 prescaler, plus control logic as shown in Figure 9-2. The divide-by-8
counter can be reset by software.
Warning: The input to the watchdog system is derived from the carry output of bit 7 of the free
running timer counter. Therefore, a reset of the timer may affect the period of the
watchdog timeout.
The watchdog system can be automatically enabled, following power-on or external reset, via a
mask option (see Section 1.2), or it can be enabled by software by writing a ‘1’ to the WDOG bit
in the miscellaneous register at $000C (see Section 9.1.2). Once enabled, the watchdog system
Figure 9-2 Watchdog system block diagram
 256
(Bit 7 of free
fosc/2
fosc/32
Main CPU
 8 watchdog
counter
WDOG bit Control logic
Latch
+
Reset
Schmitt Input
protectiontrigger
pin
Power-on
S
R
Enable
Reset
clock
 4
prescaler running counter)
MOTOROLA
9-4 MC68HC05B6RESETS AND INTERRUPTS
9
cannot be disabled by software (writing a ‘zero’ to the WDOG bit has no effect at any time). In
addition, the WDOG bit acts as a reset mechanism f or the watchdog counter. Writing a ‘1’ to this
bit clears the counter to its initial value and prevents a watchdog timeout.
WDOG — Watchdog enable/disable
The WDOG bit can be used to enable the watchdog timer previously disabled by a mask option.
Following a watchdog reset the state of the WDOG bit is as defined by the mask option specified.
1 (set) – Watchdog enabled and counter cleared.
0 (clear) – The watchdog cannot be disabled by software; writing a zero to this
bit has no effect.
The divide-by-8 watchdog counter will generate a main reset of the chip when it reaches its final
state; seven clocks are necessary to bring the watchdog counter from its clear state to its final
state. This reset appears after time tDOG since the last clear or since the enable of the watchdog
counter system. The watchdog counter, therefore, has to be cleared periodically, by software, with
a period less than tDOG.
The reset generated by the watchdog system is apparent at the RESET pin (see Figure 9-2). The
RESET pin level is re-entered in the control logic, and when it has been maintained at level ‘zero’
for a minimum of tDOGL, the RESET pin is released.
9.1.4.1 COP watchdog during STOP mode
The STOP instruction is inhibited when the watchdog system is enabled. If a STOP instruction is
executed while the watchdog system is enab led, then a w atchdog reset will occur as if there were
a watchdog timeout. In the case of a watchdog reset due to a STOP instruction, the oscillator will
not be aff ected, thus there will be no tPORL cycles start-up delay. On start-up, the w atchdog will be
configured according to the user specified mask option.
9.1.4.2 COP watchdog during WAIT mode
The state of the watchdog during WAIT mode is selected via a mask option (see Section 1.2) to
be one of the options below:
Watchdog enabled — the watchdog counter will continue to operate during WAIT mode and a
reset will occur after time tDOG.
Watchdog disabled — on entering WAIT mode, the watchdog counter system is reset and
disabled. On exiting WAIT mode the counter resumes normal operation.
MC68HC05B6 MOTOROLA
9-5
RESETS AND INTERRUPTS
9
9.1.5 Functions affected by reset
When processing stops within the MCU f or any reason, i.e. power-on reset, external reset or the
execution of a STOP or WAIT instruction, various internal functions of the MCU are affected.
Table 9-1 sho ws the resulting action of any type of system reset, b ut not necessarily in the order
in which they occur.
Table 9-1 Effect of RESET, POR, STOP and WAIT
Function/effect RESET POR WAIT STOP
Timer prescaler set to zero x x – –
Timer counter set to $FFFC x x – –
All timer enable bits cleared (disable) x x – –
Data direction registers cleared (inputs) x x – –
Stack pointer set to $00FF x x – –
Force internal address bus to restart x x – –
Vector $1FFE, $1FFF x x – –
Interrupt mask bit (I-bit CCR) set to 1 x x – –
Interrupt mask bit (I-bit CCR) cleared – – x x
Set interrupt enable bit (INTE) x x – –
Set POR bit in miscellaneous register – x – –
Reset STOP latch x x – –
Reset IRQ latch x x – –
Reset WAIT latch x x – –
SCI disabled x x – –
SCI status bits cleared (except TDRE and TC) x x – –
SCI interrupt enable bits cleared x x – –
SCI status bits TDRE and TC set x x – –
Oscillator disabled for 4064 cycles – x – x
Timer clock cleared – x – x
SCI clock cleared – x – x
A/D disabled x x – x
SM bit in the miscellaneous register cleared x x – x
Watchdog counter reset x x x x
WDOG bit in the miscellaneous register reset x x – x
EEPROM control bits (see Section 3.5.1) x x – x
x = Described action takes place
– = Described action does not take place
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9-6 MC68HC05B6RESETS AND INTERRUPTS
9
9.2 Interrupts
The MCU can be interrupted by four different sources: three maskable hardware interrupts and
one non maskable software interrupt:
• External signal on the IRQ pin
• Serial communications interface (SCI)
• Programmable timer
• Software interrupt instruction (SWI)
Interrupts cause the processor to save the register contents on the stack and to set the interrupt
mask (I-bit) to pre vent additional interrupts. The RTI instruction (ReTurn from Interrupt) causes the
register contents to be recovered from the stack and normal processing to resume. While
executing the R TI instruction, the v alue of the I-bit is replaced b y the corresponding I-bit stored on
the stack.
Unlike reset, hardware interrupts do not cause the current instruction execution to be halted, but
are considered pending until the current instruction is complete. The current instruction is the one
already fetched and being operated on. When the current instruction is complete, the processor
checks all pending hardware interrupts. If interrupts are not masked (I-bit clear) and the
corresponding interrupt enable bit is set, the processor proceeds with interrupt processing;
otherwise, the next instruction is fetched and executed.
Note:
Power-on and external reset clear all interr upt enable bits, but set the INTE bit in the
miscellaneous register, thus preventing interrupts during the reset sequence.
9.2.1 Interrupt priorities
Each potential interrupt source is assigned a priority level, which means that if more than one
interrupt is pending at the same time, the processor will ser vice the one with the highest priority
first. F or example, if both an e xternal interrupt and a timer interrupt are pending after an instruction
execution, the external interrupt is serviced first.
Table 9-2 shows the relative priority of all the possible interrupt sources. Figure 9-3 shows
the interrupt processing flow.
9.2.2 Nonmaskable software interrupt (SWI)
The software interrupt (SWI) is an executable instruction and a nonmaskable interrupt: it is
executed regardless of the state of the I-bit in the CCR. If the I-bit is zero (interrupts enabled), SWI
is executed after interrupts that were pending when the SWI was fetched, but before interrupts
MC68HC05B6 MOTOROLA
9-7
RESETS AND INTERRUPTS
9
generated after the SWI was fetched. The SWI interrupt service routine address is specified by
the contents of memory locations $1FFC and $1FFD.
9.2.3 Maskable hardware interrupts
If the interrupt mask bit in the CCR is set, all maskable interrupts (internal and external) are
masked. Clearing the I-bit allows interrupt processing to occur.
Note:
The internal interrupt latch is cleared in the first part of the interrupt service routine;
therefore, one external interrupt pulse could be latched and ser viced as soon as the
I-bit is cleared.
9.2.3.1 External interrupt (IRQ)
If the interrupt mask in the condition code register has been cleared and the interr upt enable bit
(INTE) is set and the signal on the external interrupt pin (IRQ) satisfies the condition selected by
the option control bits (INTP and INTN), then the external interrupt is recogniz ed. INTE, INTP and
INTN are all bits contained in the miscellaneous register at $000C. When the interrupt is
recognized, the current state of the CPU is pushed onto the stac k and the I-bit is set. This masks
further interrupts until the present one is serviced. The external interrupt service routine address
is specified by the content of memory locations $1FFA and $1FFB.
Table 9-2 Interrupt priorities
Source Register Flags Vector address Priority
Reset — — $1FFE, $1FFF highest
Software interrupt (SWI) — — $1FFC, $1FFD
External interrupt (IRQ) — — $1FFA, $1FFB
Timer input captures TSR ICF1, ICF2 $1FF8, $1FF9
Timer output compares TSR OCF1, OCF2 $1FF6, $1FF7
Timer overflow TSR TOF $1FF4, $1FF5
Serial communications
interface (SCI) SCSR TDRE, TC, OR,
RDRF, IDLE $1FF2, $1FF3 lowest
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9-8 MC68HC05B6RESETS AND INTERRUPTS
9
Figure 9-3 Interrupt flow chart
Reset
Is I-bit set?
IRQ
external interrupt?
Timer
internal interrupt?
SCI
internal interrupt?
Fetch next
instruction
Execute instruction
Clear IRQ request
latch
Stack
PC, X, A, CC
Set I-bit
Load PC from:
IRQ: $1FFA-$1FFB
Timer IC: $1FF8-$1FF9
Timer OC: $1FF6-$1FF7
Timer OVF:$1FF4-$1FF5
SCI: $1FF2-$1FF3
Complete interr upt
routine and execute R TI
MC68HC05B6 MOTOROLA
9-9
RESETS AND INTERRUPTS
9
9.2.3.2 Miscellaneous register
Note:
The bits shown shaded in the above representation are explained individually in the
relevant sections of this manual. The complete register plus an explanation of each bit
can be found in Section 3.8.
INTP, INTN — External interrupt sensitivity options
These two bits allow the user to select which edge the IRQ pin is sensitive to as shown in Table
9-3. Both bits can be written to only while the I-bit is set, and are cleared by power-on or external
reset. Therefore the device is initialised with negative edge and low level sensitivity.
INTE — External interrupt enable
1 (set) – External interrupt function (IRQ) enabled.
0 (clear) – External interrupt function (IRQ) disabled.
The INTE bit can be written to only while the I-bit is set, and is set by power-on or external reset,
thus enabling the external interrupt function.
Table 9-3 describes the various triggering options available for theIRQ pin, however it is important
to re-emphasize here that in order to avoid any conflict and spurious interrupt, it is only possible
to change the external interrupt options while the I-bit is set. Any attempt to change the external
interrupt option while the I-bit is clear will be unsuccessful. If an external interrupt is pending, it will
automatically be cleared when selecting a different interrupt option.
Note:
If the external interrupt function is disabled by the INTE bit and an external interrupt is
sensed by the edge detector circuitry, then the interrupt request is latched and the
interrupt stays pending until the INTE bit is set. The internal latch of the external
interrupt is cleared in the first part of the service routine (except for the low level
Address bit 7 bit 6 bit 5 bit 4 bit 3 bit 2 bit 1 bit 0 State
on reset
Miscellaneous $000C POR INTP INTN INTE SFA SFB SM WDOG ?001 000?
Table 9-3 IRQ sensitivity
INTP INTN IRQ sensitivity
0 0 Negative edge and low level sensitive
0 1 Negative edge only
1 0 Positive edge only
1 1 Positive and negative edge sensitive
MOTOROLA
9-10 MC68HC05B6RESETS AND INTERRUPTS
9
interrupt which is not latched); therefore, only one external interrupt pulse can be
latched during tILIL and serviced as soon as the I-bit is cleared.
9.2.3.3 Timer interrupts
There are five different timer interrupt flags (ICF1, ICF2, OCF1, OCF2 and T OF) that will cause a
timer interrupt whenever they are set and enabled. These five interrupt flags are found in the five
most significant bits of the timer status register (TSR) at location $0013. ICF1 and ICF2 will vector
to the service routine defined b y $1FF8-$1FF9, OCF1 and OCF2 will v ector to the service routine
defined by $1FF6–$1FF7 and TOF will vector to the service routine defined by $1FF4–$1FF5 as
shown in Figure 5-1.
There are three corresponding enable bits; ICIE for ICF1 and ICF2, OCIE for OCF1 and OCF2,
and TOIE for TOF. These enable bits are located in the timer control register (TCR) at address
$0012. See Section 5.2.1 and Section 5.2.2 for further information.
9.2.3.4 Serial communications interface (SCI) interrupts
There are five different interrupt flags (TDRE, TC , OR, RDRF and IDLE) that cause SCI interrupts
whenever they are set and enab led. These five interrupt flags are found in the fiv e most significant
bits of the SCI status register (SCSR) at location $0010.
There are four corresponding enable bits: TIE for TDRE, TCIE f or TC, RIE for OR and RDRF, and
ILIE for IDLE. These enable bits are located in the serial communications control register 2
(SCCR2) at address $000F. See Section 6.11.3 and Section 6.11.4.
The SCI interrupt causes the program counter to vector to the address pointed to by memory
locations $1FF2 and $1FF3 which contain the starting address of the interrupt ser vice routine.
Software in the SCI interrupt service routine must determine the priority and cause of the interrupt
by examining the interrupt flags and the status bits located in the serial communications status
register SCSR (address $0010).
The general sequence for clearing an interrupt is a software sequence of accessing the serial
communications status register while the flag is set followed by a read or write of an associated
register. Refer to Section 6 for a description of the SCI system and its interrupts.
MC68HC05B6 MOTOROLA
9-11
RESETS AND INTERRUPTS
9
9.2.4 Hardware controlled interrupt sequence
The following three functions: reset, STOP and WAIT, are not in the strictest sense interrupts. However,
they are acted upon in a similar manner. Flowcharts for STOP and W AIT are sho wn in Figure 2-4.
RESET: A reset condition causes the program to vector to its starting address, which is
contained in memory locations $1FFE (MSB) and $1FFF (LSB). The I-bit in the
condition code register is also set, to disable interrupts.
STOP: The STOP instruction causes the oscillator to be turned off and the processor to ‘sleep’
until an external interrupt (IRQ) or occurs or the device is reset.
WAIT: The WAIT instr uction causes all processor clocks to stop, but leaves the timer clocks
running. This ‘rest’ state of the processor can be cleared by reset, an external interrupt
(IRQ), a timer interrupt or an SCI interrupt. There are no special W AIT vectors for these
individual interrupts.
MOTOROLA
9-12 MC68HC05B6RESETS AND INTERRUPTS
THIS PAGE INTENTIONALLY LEFT BLANK
9
MC68HC05B6 MOTOROLA
10-1
CPU CORE AND INSTRUCTION SET
10
10
CPU CORE AND INSTRUCTION SET
This section provides a description of the CPU core registers, the instruction set and the
addressing modes of the MC68HC05B6.
10.1 Registers
The MCU contains five registers, as shown in the programming model of Figure 10-1. The
interrupt stacking order is shown in Figure 10-2.
Figure 10-1 Programming model
Figure 10-2 Stacking order
Accumulator
Index register
Program counter
Stack pointer
Condition code register
Carry / borrow
Zero
Negative
Interrupt mask
Half carry
7 0
7 0
15 7 0
0
15 7 0
000000011
7 0
11 1 H I N Z C
000
Condition code register
Accumulator
Index register
Program counter high
Program counter low
7 0 Stack
Unstack
Decreasing
memory
address
Increasing
memory
address
Interrupt
Return
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10-2 MC68HC05B6CPU CORE AND INSTRUCTION SET
10
10.1.1 Accumulator (A)
The accumulator is a general purpose 8-bit register used to hold operands and results of
arithmetic calculations or data manipulations.
10.1.2 Index register (X)
The index register is an 8-bit register, which can contain the indexed addressing value used to
create an effective address. The index register may also be used as a temporary storage area.
10.1.3 Program counter (PC)
The program counter is a 16-bit register , which contains the address of the ne xt byte to be f etched.
Although the M68HC05 CPU core can address 64 kbytes of memory, the actual address range of
the MC68HC05B6 is limited to 8 kbytes. The three most significant bits of the Program Counter
are therefore not used and are permanently set to zero.
10.1.4 Stack pointer (SP)
The stack pointer is a 16-bit register, which contains the address of the next free location on the
stack. During an MCU reset or the reset stack pointer (RSP) instruction, the stack pointer is set to
location $00FF. The stack pointer is then decremented as data is pushed onto the stack and
incremented as data is pulled from the stack.
When accessing memory, the ten most significant bits are permanently set to 0000000011. These
ten bits are appended to the six least significant register bits to produce an address within the
range of $00C0 to $00FF. Subroutines and interrupts may use up to 64 (decimal) locations. If 64
locations are exceeded, the stack pointer wraps around and overwrites the previously stored
information. A subroutine call occupies two locations on the stack; an interrupt uses five locations.
10.1.5 Condition code register (CCR)
The CCR is a 5-bit register in which four bits are used to indicate the results of the instruction just
executed, and the fifth bit indicates whether interrupts are masked. These bits can be individually
tested by a program, and specific actions can be taken as a result of their state. Each bit is
explained in the following paragraphs.
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10-3
CPU CORE AND INSTRUCTION SET
10
Half carry (H)
This bit is set during ADD and ADC oper ations to indicate that a carry occurred betw een bits 3 and 4.
Interrupt (I)
When this bit is set all maskable interrupts are masked. If an interrupt occurs while this bit is set,
the interrupt is latched and remains pending until the interrupt bit is cleared.
Negative (N)
When set, this bit indicates that the result of the last arithmetic, logical, or data manipulation was
negative.
Zero (Z)
When set, this bit indicates that the result of the last arithmetic, logical, or data manipulation was zero .
Carry/borrow (C)
When set, this bit indicates that a carry or borrow out of the arithmetic logical unit (ALU) occurred
during the last arithmetic operation. This bit is also affected during bit test and branch instructions
and during shifts and rotates.
10.2 Instruction set
The MCU has a set of 62 basic instructions. They can be grouped into five different types as
follows:
– Register/memory
– Read/modify/write
– Branch
– Bit manipulation
– Control
The following paragraphs briefly explain each type. All the instructions within a given type are
presented in individual tables.
This MCU uses all the instructions available in the M146805 CMOS family plus one more: the
unsigned multiply (MUL) instruction. This instruction allows unsigned multiplication of the contents
of the accumulator (A) and the index register (X). The high-order product is then stored in the
index register and the low-order product is stored in the accumulator. A detailed definition of the
MUL instruction is shown in Table 10-1.
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10-4 MC68HC05B6CPU CORE AND INSTRUCTION SET
10
10.2.1 Register/memory Instructions
Most of these instructions use two operands. The first operand is either the accumulator or the
index register. The second operand is obtained from memory using one of the addressing modes.
The jump unconditional (JMP) and jump to subroutine (JSR) instructions have no register
operand. Refer to Table 10-2 for a complete list of register/memory instructions.
10.2.2 Branch instructions
These instructions cause the program to branch if a particular condition is met; otherwise, no
operation is performed. Branch instructions are two-byte instructions. Refer to Table 10-3.
10.2.3 Bit manipulation instructions
The MCU can set or clear any writable bit that resides in the first 256 bytes of the memory space
(page 0). All port data and data direction registers, timer and serial interface registers,
control/status registers and a por tion of the on-chip RAM reside in page 0. An additional feature
allows the softw are to test and branch on the state of any bit within these locations . The bit set, bit
clear, bit test and branch functions are all implemented with single instructions. For the test and
branch instructions, the value of the bit tested is also placed in the carry bit of the condition code
register. Refer to Table 10-4.
10.2.4 Read/modify/write instructions
These instructions read a memory location or a register, modify or test its contents, and write the
modified value back to memory or to the register . The test f or negative or zero (TST) instruction is
an exception to this sequence of reading, modifying and writing, since it does not modify the value.
Refer to Table 10-5 for a complete list of read/modify/write instructions.
10.2.5 Control instructions
These instructions are register ref erence instructions and are used to control processor operation
during program execution. Refer to Table 10-6 for a complete list of control instructions.
10.2.6 Tables
Tables for all the instruction types listed above follow. In addition there is a complete alphabetical
listing of all the instructions (see Table 10-7 and Table 10-8), and an opcode map f or the instruction
set of the M68HC05 MCU family (see Table 10-9).
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10-5
CPU CORE AND INSTRUCTION SET
10
Table 10-1 MUL instruction
Operation X:A
←
X*A
Description Multiplies the eight bits in the index register by the eight
bits in the accum ulator and places the 16-bit result in the
concatenated accumulator and index register.
Condition
codes
H : Cleared
I : Not affected
N : Not affected
Z : Not affected
C : Cleared
Source MUL
Form Addressing mode Cycles Bytes Opcode
Inherent 11 1 $42
Table 10-2 Register/memory instructions
Addressing modes
Immediate Direct Extended Indexed
(no
offset)
Indexed
(8-bit
offset)
Indexed
(16-bit
offset)
Function
Mnemonic
Opcode
# Bytes
# Cycles
Opcode
# Bytes
# Cycles
Opcode
# Bytes
# Cycles
Opcode
# Bytes
# Cycles
Opcode
# Bytes
# Cycles
Opcode
# Bytes
# Cycles
Load A from memory LDA A6 2 2 B6 2 3 C6 3 4 F6 1 3 E6 2 4 D6 3 5
Load X from memory LDX AE 2 2 BE 2 3 CE 3 4 FE 1 3 EE 2 4 DE 3 5
Store A in memory STA B7 2 4 C7 3 5 F7 1 4 E7 2 5 D7 3 6
Store X in memory STX BF 2 4 CF 3 5 FF 1 4 EF 2 5 DF 3 6
Add memory to A ADD AB 2 2 BB 2 3 CB 3 4 FB 1 3 EB 2 4 DB 3 5
Add memory and carry to A ADC A9 2 2 B9 2 3 C9 3 4 F9 1 3 E9 2 4 D9 3 5
Subtract memory SUB A0 2 2 B0 2 3 C0 3 4 F0 1 3 E0 2 4 D0 3 5
Subtract memory from A
with borrow SBC A2 2 2 B2 2 3 C2 3 4 F2 1 3 E2 2 4 D2 3 5
AND memory with A AND A4 2 2 B4 2 3 C4 3 4 F4 1 3 E4 2 4 D4 3 5
OR memory with A ORA AA 2 2 BA 2 3 CA 3 4 FA 1 3 EA 2 4 DA 3 5
Exclusive OR memory with A EOR A8 2 2 B8 2 3 C8 3 4 F8 1 3 E8 2 4 D8 3 5
Arithmetic compare A
with memory CMP A1 2 2 B1 2 3 C1 3 4 F1 1 3 E1 2 4 D1 3 5
Arithmetic compare X
with memory CPX A3 2 2 B3 2 3 C3 3 4 F3 1 3 E3 2 4 D3 3 5
Bit test memory with A
(logical compare) BIT A5 2 2 B5 2 3 C5 3 4 F5 1 3 E5 2 4 D5 3 5
Jump unconditional JMP BC 2 2 CC 3 3 FC 1 2 EC 2 3 DC 3 4
Jump to subroutine JSR BD 2 5 CD 3 6 FD 1 5 ED 2 6 DD 3 7
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Table 10-3 Branch instructions
Relative addressing mode
Function Mnemonic Opcode # Bytes # Cycles
Branch always BRA 20 2 3
Branch never BRN 21 2 3
Branch if higher BHI 22 2 3
Branch if lower or same BLS 23 2 3
Branch if carry clear BCC 24 2 3
(Branch if higher or same) (BHS) 24 2 3
Branch if carry set BCS 25 2 3
(Branch if lower) (BLO) 25 2 3
Branch if not equal BNE 26 2 3
Branch if equal BEQ 27 2 3
Branch if half carry clear BHCC 28 2 3
Branch if half carry set BHCS 29 2 3
Branch if plus BPL 2A 2 3
Branch if minus BMI 2B 2 3
Branch if interrupt mask bit is clear BMC 2C 2 3
Branch if interrupt mask bit is set BMS 2D 2 3
Branch if interrupt line is low BIL 2E 2 3
Branch if interrupt line is high BIH 2F 2 3
Branch to subroutine BSR AD 2 6
Table 10-4 Bit manipulation instructions
Addressing Modes
Bit set/clear Bit test and branch
Function Mnemonic Opcode # Bytes # Cycles Opcode # Bytes # Cycles
Branch if bit n is set BRSET n (n=0–7) 2•n 3 5
Branch if bit n is clear BRCLR n (n=0–7) 01+2•n 3 5
Set bit n BSET n (n=0–7) 10+2•n 2 5
Clear bit n BCLR n (n=0–7) 11+2•n 2 5
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CPU CORE AND INSTRUCTION SET
10
Table 10-5 Read/modify/write instructions
Addressing modes
Inherent
(A) Inherent
(X) Direct Indexed
(no
offset)
Indexed
(8-bit
offset)
Function
Mnemonic
Opcode
# Bytes
# Cycles
Opcode
# Bytes
# Cycles
Opcode
# Bytes
# Cycles
Opcode
# Bytes
# Cycles
Opcode
# Bytes
# Cycles
Increment INC 4C 1 3 5C 1 3 3C 2 5 7C 1 5 6C 2 6
Decrement DEC 4A 1 3 5A 1 3 3A 2 5 7A 1 5 6A 2 6
Clear CLR 4F 1 3 5F 1 3 3F 2 5 7F 1 5 6F 2 6
Complement COM 43 1 3 53 1 3 33 2 5 73 1 5 63 2 6
Negate (two’s complement) NEG 40 1 3 50 1 3 30 2 5 70 1 5 60 2 6
Rotate left through carry ROL 49 1 3 59 1 3 39 2 5 79 1 5 69 2 6
Rotate right through carry ROR 46 1 3 56 1 3 36 2 5 76 1 5 66 2 6
Logical shift left LSL 48 1 3 58 1 3 38 2 5 78 1 5 68 2 6
Logical shift right LSR 44 1 3 54 1 3 34 2 5 74 1 5 64 2 6
Arithmetic shift right ASR 47 1 3 57 1 3 37 2 5 77 1 5 67 2 6
Test for negative or zero TST 4D 1 3 5D 1 3 3D 2 4 7D 1 4 6D 2 5
Multiply MUL 42 1 11
Table 10-6 Control instructions
Inherent addressing mode
Function Mnemonic Opcode # Bytes # Cycles
Transfer A to X TAX 97 1 2
Transfer X to A TXA 9F 1 2
Set carry bit SEC 99 1 2
Clear carry bit CLC 98 1 2
Set interrupt mask bit SEI 9B 1 2
Clear interrupt mask bit CLI 9A 1 2
Software interrupt SWI 83 1 10
Return from subroutine RTS 81 1 6
Return from interrupt RTI 80 1 9
Reset stack pointer RSP 9C 1 2
No-operation NOP 9D 1 2
Stop STOP 8E 1 2
Wait WAIT 8F 1 2
MOTOROLA
10-8 MC68HC05B6CPU CORE AND INSTRUCTION SET
10
Table 10-7 Instruction set (1 of 2)
Mnemonic Addressing modes Condition codes
INH IMM DIR EXT REL IX IX1 IX2 BSC BTB H I N Z C
ADC •
ADD •
AND • • •
ASL • •
ASR • •
BCC • • • • •
BCLR • • • • •
BCS • • • • •
BEQ • • • • •
BHCC • • • • •
BHCS • • • • •
BHI • • • • •
BHS • • • • •
BIH • • • • •
BIL • • • • •
BIT • • •
BLO • • • • •
BLS • • • • •
BMC • • • • •
BMI • • • • •
BMS • • • • •
BNE • • • • •
BPL • • • • •
BRA • • • • •
BRN • • • • •
BRCLR • • • •
BRSET • • • •
BSET • • • • •
BSR • • • • •
CLC • • • • 0
CLI • 0 • • •
CLR • • 0 1 •
CMP • •
Condition code symbols
H Half carry (from bit 3) Tested and set if true,
cleared otherwise
I Interrupt mask • Not affected
N Negate (sign bit) ? Load CCR from stack
Z Zero 0 Cleared
C Carry/borrow 1 Set
Not implemented
Address mode abbreviations
BSC Bit set/clear IMM Immediate
BTB Bit test & branch IX Indexed (no offset)
DIR Direct IX1 Indexed, 1 byte offset
EXT Extended IX2 Indexed, 2 byte offset
INH Inherent REL Relative
MC68HC05B6 MOTOROLA
10-9
CPU CORE AND INSTRUCTION SET
10
Table 10-8 Instruction set (2 of 2)
Mnemonic Addressing modes Condition codes
INH IMM DIR EXT REL IX IX1 IX2 BSC BTB H I N Z C
COM • • 1
CPX • •
DEC • • •
EOR • • •
INC • • •
JMP • • • • •
JSR • • • • •
LDA • • •
LDX • • •
LSL • •
LSR • • 0
MUL 0 • • • 0
NEG • •
NOP • • • • •
ORA • • •
ROL • •
ROR • •
RSP • • • • •
RTI ? ? ? ? ?
RTS • • • • •
SBC • •
SEC • • • • 1
SEI • 1 • • •
STA • • •
STOP • 0 • • •
STX • • •
SUB • •
SWI • 1 • • •
TAX • • • • •
TST • • •
TXA • • • • •
WAIT • 0 • • •
Condition code symbols
H Half carry (from bit 3) Tested and set if true,
cleared otherwise
I Interrupt mask • Not affected
N Negate (sign bit) ? Load CCR from stack
Z Zero 0 Cleared
C Carry/borrow 1 Set
Not implemented
Address mode abbreviations
BSC Bit set/clear IMM Immediate
BTB Bit test & branch IX Indexed (no offset)
DIR Direct IX1 Indexed, 1 byte offset
EXT Extended IX2 Indexed, 2 byte offset
INH Inherent REL Relative
MOTOROLA
10-10 MC68HC05B6CPU CORE AND INSTRUCTION SET
10
Table 10-9 M68HC05 opcode map
Bit manipulation Branch Read/modify/write Control Register/memory
BTB BSC REL DIR INH INH IX1 IX INH INH IMM DIR EXT IX2 IX1 IX
High 0 1 2 3 4 5 6 7 8 9 A B C D E F High
Low 0000 0001 0010 0011 0100 0101 0110 0111 1000 1001 1010 1011 1100 1101 1110 1111 Low
0
0000 553533659 234543 0
0000
BRSET0 BSET0 BRA NEG NEGA NEGX NEG NEG RTI SUB SUB SUB SUB SUB SUB
3BTB 2BSC 2REL 2DIR 1INH 1INH 2IX1 1IX 1INH 2IMM 2DIR 3EXT 3IX2 2IX1 1IX
1
0001 5 5 3 6 2 3 4 5 4 3 1
0001
BRCLR0 BCLR0 BRN RTS CMP CMP CMP CMP CMP CMP
3BTB 2BSC 2REL 1INH 2IMM 2DIR 3EXT 3IX2 2IX1 1IX
2
0010 5 5 3 11 2 3 4 5 4 3 2
0010
BRSET1 BSET1 BHI MUL SBC SBC SBC SBC SBC SBC
3BTB 2BSC 2REL 1INH 2IMM 2DIR 3EXT 3IX2 2IX1 1IX
3
0011 5 5 3 5 3 3 6 5 10 2 3 4 5 4 3 3
0011
BRCLR1 BCLR1 BLS COM COMA COMX COM COM SWI CPX CPX CPX CPX CPX CPX
3BTB 2BSC 2REL 2DIR 1INH 1INH 2IX1 1IX 1INH 2IMM 2DIR 3EXT 3IX2 2IX1 1IX
4
0100 55353365 234543 4
0100
BRSET2 BSET2 BCC LSR LSRA LSRX LSR LSR AND AND AND AND AND AND
3BTB 2BSC 2REL 2DIR 1INH 1INH 2IX1 1IX 2IMM 2DIR 3EXT 3IX2 2IX1 1IX
5
0101 553 234543 5
0101
BRCLR2 BCLR2 BCS BIT BIT BIT BIT BIT BIT
3BTB 2BSC 2REL 2IMM 2DIR 3EXT 3IX2 2IX1 1IX
6
0110 55353365 234543 6
0110
BRSET3 BSET3 BNE ROR RORA RORX ROR ROR LDA LDA LDA LDA LDA LDA
3BTB 2BSC 2REL 2DIR 1INH 1INH 2IX1 1IX 2IMM 2DIR 3EXT 3IX2 2IX1 1IX
7
0111 55353365 2 45654 7
0111
BRCLR3 BCLR3 BEQ ASR ASRA ASRX ASR ASR TAX STA STA STA STA STA
3BTB 2BSC 2REL 2DIR 1INH 1INH 2IX1 1IX 1INH 2DIR 3EXT 3IX2 2IX1 1IX
8
1000 55353365 2234543 8
1000
BRSET4 BSET4 BHCC LSL LSLA LSLX LSL LSL CLC EOR EOR EOR EOR EOR EOR
3BTB 2BSC 2REL 2DIR 1INH 1INH 2IX1 1IX 1INH 2IMM 2DIR 3EXT 3IX2 2IX1 1IX
9
1001 55353365 2234543 9
1001
BRCLR4 BCLR4 BHCS ROL ROLA ROLX ROL ROL SEC ADC ADC ADC ADC ADC ADC
3BTB 2BSC 2REL 2DIR 1INH 1INH 2IX1 1IX 1INH 2IMM 2DIR 3EXT 3IX2 2IX1 1IX
A
1010 55353365 2234543 A
1010
BRSET5 BSET5 BPL DEC DECA DECX DEC DEC CLI ORA ORA ORA ORA ORA ORA
3BTB 2BSC 2REL 2DIR 1INH 1INH 2IX1 1IX 1INH 2IMM 2DIR 3EXT 3IX2 2IX1 1IX
B
1011 553 2234543 B
1011
BRCLR5 BCLR5 BMI SEI ADD ADD ADD ADD ADD ADD
3BTB 2BSC 2REL 1INH 2IMM 2DIR 3EXT 3IX2 2IX1 1IX
C
1100 55353365 2 23432 C
1100
BRSET6 BSET6 BMC INC INCA INCX INC INC RSP JMP JMP JMP JMP JMP
3BTB 2BSC 2REL 2DIR 1INH 1INH 2IX1 1IX 1INH 2DIR 3EXT 3IX2 2IX1 1IX
D
1101 55343354 2656765 D
1101
BRCLR6 BCLR6 BMS TST TSTA TSTX TST TST NOP BSR JSR JSR JSR JSR JSR
3BTB 2BSC 2REL 2DIR 1INH 1INH 2IX1 1IX 1INH 2REL 2DIR 3EXT 3IX2 2IX1 1IX
E
1110 5 5 3 2 2 3 4 5 4 3 E
1110
BRSET7 BSET7 BIL STOP LDX LDX LDX LDX LDX LDX
3BTB 2BSC 2REL 1INH 2IMM 2DIR 3EXT 3IX2 2IX1 1IX
F
1111 5535336522 45654 F
1111
BRCLR7 BCLR7 BIH CLR CLRA CLRX CLR CLR WAIT TXA STX STX STX STX STX
3BTB 2BSC 2REL 2DIR 1INH 1INH 2IX1 1IX 1INH 1INH 2DIR 3EXT 3IX2 2IX1 1IX
F
1111
30
0000
SUB
1IX
Opcode in hexadecimal
Opcode in binary
Address modeCycles
Bytes
Mnemonic
LegendAbbreviations for address modes and registers
BSC
BTB
DIR
EXT
INH
IMM
IX
IX1
IX2
REL
A
X
Bit set/clear
Bit test and branch
Direct
Extended
Inherent
Immediate
Indexed (no offset)
Indexed, 1 byte (8-bit) offset
Indexed, 2 byte (16-bit) offset
Relative
Accumulator
Index register Not implemented
MC68HC05B6 MOTOROLA
10-11
CPU CORE AND INSTRUCTION SET
10
10.3 Addressing modes
Ten different addressing modes provide programmers with the flexibility to optimize their code for
all situations. The various indexed addressing modes make it possible to locate data tables, code
conversion tables and scaling tables anywhere in the memory space. Short indexed accesses are
single byte instructions; the longest instructions (three bytes) enable access to tables throughout
memory. Short absolute (direct) and long absolute (extended) addressing are also included. One
or two byte direct addressing instructions access all data bytes in most applications. Extended
addressing permits jump instructions to reach all memory locations.
The term ‘effective address’ (EA) is used in describing the various addressing modes. The
effective address is defined as the address from which the argument for an instruction is fetched
or stored. The ten addressing modes of the processor are described below. Parentheses are used
to indicate ‘contents of’ the location or register referred to. For example, (PC) indicates the
contents of the location pointed to by the PC (program counter). An arrow indicates ‘is replaced
by’ and a colon indicates concatenation of two bytes. For additional details and graphical
illustrations, refer to the
M6805 HMOS/M146805 CMOS Family Microcomputer/
Microprocessor User's Manual
or to the
M68HC05 Applications Guide.
10.3.1 Inherent
In the inherent addressing mode, all the information necessary to execute the instruction is
contained in the opcode. Operations specifying only the index register or accumulator, as well as
the control instruction, with no other arguments are included in this mode. These instructions are
one byte long.
10.3.2 Immediate
In the immediate addressing mode, the operand is contained in the b yte immediately f ollowing the
opcode. The immediate addressing mode is used to access constants that do not change during
program execution (e.g. a constant used to initialize a loop counter).
EA = PC+1; PC ← PC+2
10.3.3 Direct
In the direct addressing mode, the effective address of the argument is contained in a single byte
following the opcode byte. Direct addressing allows the user to directly address the lowest 256
bytes in memory with a single two-byte instruction.
EA = (PC+1); PC ←PC+2
Address bus high ←0; Address bus low ←(PC+1)
MOTOROLA
10-12 MC68HC05B6CPU CORE AND INSTRUCTION SET
10
10.3.4 Extended
In the extended addressing mode, the effective address of the argument is contained in the two
bytes following the opcode byte. Instructions with extended addressing mode are capable of
referencing arguments anywhere in memory with a single three-byte instruction. When using the
Motorola assembler, the user need not specify whether an instruction uses direct or extended
addressing. The assembler automatically selects the short form of the instruction.
EA = (PC+1):(PC+2); PC ←PC+3
Address bus high ←(PC+1); Address bus low ←(PC+2)
10.3.5 Indexed, no offset
In the indexed, no offset addressing mode, the effective address of the argument is contained in
the 8-bit index register. This addressing mode can access the first 256 memory locations. These
instructions are only one byte long. This mode is often used to move a pointer through a table or
to hold the address of a frequently referenced RAM or I/O location.
EA = X; PC ←PC+1
Address bus high ←0; Address bus low ←X
10.3.6 Indexed, 8-bit offset
In the indexed, 8-bit offset addressing mode, the effective address is the sum of the contents of
the unsigned 8-bit index register and the unsigned byte following the opcode. Therefore the
operand can be located anywhere within the lo west 511 memory locations. This addressing mode
is useful for selecting the mth element in an n element table.
EA = X+(PC+1); PC ←PC+2
Address bus high ← K; Address bus low ←X+(PC+1)
where K = the carry from the addition of X and (PC+1)
10.3.7 Indexed, 16-bit offset
In the indexed, 16-bit offset addressing mode, the effective address is the sum of the contents of
the unsigned 8-bit index register and the two unsigned bytes following the opcode. This address
mode can be used in a manner similar to indexed, 8-bit offset e xcept that this three-byte instruction
allows tables to be anywhere in memor y. As with direct and extended addressing, the Motorola
assembler determines the shortest form of indexed addressing.
EA = X+[(PC+1):(PC+2)]; PC ←PC+3
Address bus high ←(PC+1)+K; Address bus low ←X+(PC+2)
where K = the carry from the addition of X and (PC+2)
MC68HC05B6 MOTOROLA
10-13
CPU CORE AND INSTRUCTION SET
10
10.3.8 Relative
The relative addressing mode is only used in branch instructions. In relative addressing, the
contents of the 8-bit signed byte (the offset) following the opcode are added to the PC if , and only
if, the branch conditions are true. Otherwise, control proceeds to the next instruction. The span of
relative addressing is from –126 to +129 from the opcode address. The programmer need not
calculate the offset when using the Motorola assembler, since it calculates the proper offset and
checks to see that it is within the span of the branch.
EA = PC+2+(PC+1); PC ←EA if branch taken;
otherwise EA = PC ←PC+2
10.3.9 Bit set/clear
In the bit set/clear addressing mode, the bit to be set or cleared is part of the opcode. The byte
following the opcode specifies the address of the byte in which the specified bit is to be set or
cleared. Any read/write bit in the first 256 locations of memor y, including I/O, can be selectively
set or cleared with a single two-byte instruction.
EA = (PC+1); PC ←PC+2
Address bus high ←0; Address bus low ←(PC+1)
10.3.10 Bit test and branch
The bit test and branch addressing mode is a combination of direct addressing and relative
addressing. The bit to be tested and its condition (set or clear) is included in the opcode. The
address of the byte to be tested is in the single b yte immediately following the opcode b yte (EA1).
The signed relative 8-bit offset in the third byte (EA2) is added to the PC if the specified bit is set
or cleared in the specified memory location. This single three-byte instruction allows the program
to branch based on the condition of any readable bit in the first 256 locations of memory. The span
of branch is from –125 to +130 from the opcode address. The state of the tested bit is also
transferred to the carry bit of the condition code register.
EA1 = (PC+1); PC ←PC+2
Address bus high ←0; Address bus low ←(PC+1)
EA2 = PC+3+(PC+2); PC ←EA2 if branch taken;
otherwise PC ←PC+3
MOTOROLA
10-14 MC68HC05B6CPU CORE AND INSTRUCTION SET
THIS PAGE INTENTIONALLY LEFT BLANK
10
MC68HC05B6 MOTOROLA
11-1
ELECTRICAL SPECIFICATIONS
11
11
ELECTRICAL SPECIFICATIONS
This section contains the electrical specifications and associated timing information for the
MC68HC05B6.
11.1 Maximum ratings
Note:
This device contains circuitry designed to protect against damage due to high
electrostatic voltages or electric fields. However, it is recommended that normal
precautions be taken to avoid the application of any voltages higher than those given
in the maximum ratings table to this high impedance circuit. For maximum reliability all
unused inputs should be tied to either VSS or VDD.
(1) All voltages are with respect to VSS.
(2) Maximum current drain per pin is for one pin at a time, limited by an external resistor.
Table 11-1 Maximum ratings
Rating Symbol Value Unit
Supply voltage(1) VDD – 0.5 to +7.0 V
Input voltage VIN VSS – 0.5 to VDD + 0.5 V
Input voltage
– Self-check mode (
IRQ pin only) VIN VSS – 0.5 to 2VDD + 0.5 V
Operating temperature range
– Standard (MC68HC05B6)
– Extended (MC68HC05B6C)
– Automotive (MC68HC05B6M)
TATL to TH
0 to +70
–40 to +85
–40 to +125
C
Storage temperature range TSTG – 65 to +150 C
Current drain per pin (e xcluding VDD and VSS) (2)
– Source
– Sink ID
IS
25
45 mA
mA
MOTOROLA
11-2 MC68HC05B6ELECTRICAL SPECIFICATIONS
11
11.2 Thermal characteristics and power considerations
The average chip junction temperature, TJ, in degrees Celsius can be obtained from the following
equation:
[1]
where:
TA = Ambient temperature (C)
θJA = Package thermal resistance, junction-to-ambient (C/W)
PD = PINT + PI/O (W)
PINT = Internal chip power = IDD • VDD (W)
PI/O = Power dissipation on input and output pins (user determined)
An approximate relationship between PD and TJ (if PI/O is neglected) is:
[2]
Solving equations [1] and [2] for K gives:
[3]
where K is a constant f or a particular part. K can be determined by measuring PD (at equilibrium)
for a known TA. Using this value of K, the values of PD and TJ can be obtained for any value of TA
by solving the above equations. The package thermal characteristics are shown in Table 11-2.
Table 11-2 Package thermal characteristics
Characteristics Symbol Value Unit
Thermal resistance
– 64-pin quad flat package
θ
JA 50 C/W
– Plastic 56 pin shrink DIL package
θ
JA 50 C/W
– Plastic 52 pin PLCC package
θ
JA 50 C/W
Figure 11-1 Equivalent test load
TJTAPD
θJA
•( )+=
PDK
TJ
273+
---------------------
=
K PDTA273+( )• θJA PD
2
•+=
Voltage Pins R1 R2 C
4.5V PA0–7, PB0–7, PC0–7 3.26k 2.38k 50pF
3.0V PA0–7, PB0–7, PC0–7 10.91k 6.32k 50pF
VDD = 4.5/3.0V
R2
R1C
Test
point
MC68HC05B6 MOTOROLA
11-3
ELECTRICAL SPECIFICATIONS
11
11.3 DC electrical characteristics
(1) All IDD measurements taken with suitable decoupling capacitors across the po wer supply to suppress the transient
switching currents inherent in CMOS designs (see Section 2).
(2) Typical values are at mid point of voltage range and at 25C only.
(3) RUN and WAIT IDD: measured using an external square-wave clock source (fOSC = 4.2MHz); all inputs 0.2 V from
rail; no DC loads; maximum load on outputs 50pF (20pF on OSC2).
STOP /WAIT IDD: all ports configured as inputs; VIL = 0.2 V and VIH = VDD – 0.2 V: STOP IDD measured with
OSC1 = VDD.
WAIT IDD is affected linearly by the OSC2 capacitance.
Table 11-3 DC electrical characteristics for 5V operation
(VDD = 5 Vdc  10%, VSS = 0 Vdc, TA = TL to TH)
Characteristic(1) Symbol Min Typ(2) Max Unit
Output voltage
ILOAD = – 10 A
ILOAD = +10 A VOH
VOL VDD – 0.1
——
——
0.1 V
Output high voltage (ILOAD = 0.8mA)
PA0–7, PB0–7, PC0–7, TCMP1, TCMP2
Output high voltage (ILOAD = 1.6mA)
TDO, SCLK, PLMA, PLMB
VOH
VOH
VDD – 0.8
VDD – 0.8
VDD – 0.4
VDD – 0.4
—
—V
Output low voltage (ILOAD = 1.6mA)
PA0–7, PB0–7, PC0–7, TCMP1, TCMP2,
TDO, SCLK, PLMA, PLMB
Output low voltage (ILOAD = 1.6mA)
RESET
VOL
VOL
— 0.1
0.4
0.4
1V
Input high voltage
PA0–7, PB0–7, PC0–7, PD0–7, OSC1,
IRQ, RESET, TCAP1, TCAP2, RDI VIH 0.7VDD — VDD V
Input low voltage
PA0–7, PB0–7, PC0–7, OSC1, IRQ,RESET,
TCAP1, TCAP2, RDI VIL VSS — 0.2VDD V
Supply current(3)
RUN (SM = 0) (See Figure 11-2)
RUN (SM = 1) (See Figure 11-3)
WAIT (SM = 0) (See Figure 11-4)
WAIT (SM = 1) (See Figure 11-5)
STOP 0 to 70 (standard)
– 40 to 85 (extended)
– 40 to 105 (extended)
– 40 to 125 (automotive)
IDD
—
—
—
—
—
—
—
—
3.5
0.5
1
0.35
2
—
—
—
6
1.5
2
1
10
20
60
60
mA
mA
mA
mA
A
A
A
A
High-Z leakage current
PA0–7, PB0–7, PC0–7, TDO, RESET, SCLK IIL — 0.2 1 A
Input current (0 to 70)
IRQ, OSC1, TCAP1, TCAP2, RDI,
PD0/AN0-PD7/AN7 (channel not selected) IIN — 0.2
0.2 1
1 A
Input current (– 40 to 125)
IRQ, OSC1, TCAP1, TCAP2, RDI, IIN — — 5 A
Capacitance
Ports (as input or output), RESET, TDO, SCLK
IRQ, TCAP1, TCAP2, OSC1, RDI
PD0/AN0–PD7/AN7 (A/D off)
PD0/AN0–PD7/AN7 (A/D on)
COUT
CIN
CIN
CIN
—
—
—
—
—
—
12
22
12
8
TBD
TBD
pF
pF
pF
pF
MOTOROLA
11-4 MC68HC05B6ELECTRICAL SPECIFICATIONS
11
11.3.1 IDD trends for 5V operation
Figure 11-2 Run IDD vs internal operating frequency (4.5V, 5.5V)
Figure 11-3 Run IDD (SM = 1) vs internal operating frequency (4.5V, 5.5V)
Figure 11-4 Wait IDD vs internal operating frequency (4.5V, 5.5V)
8
7
6
5
4
3
2
1
00 0.5 1 1.5 2 2.5 3 3.5 4
IDD (mA)
Internal operating frequency (MHz)
5.5V
4.5V
1.2
00 0.5 1 1.5 2 2.5 3 3.5 4
IDD (mA)
Internal operating frequency (MHz)
5.5V
4.5V
1
0.8
0.6
0.4
0.2
2.5
00 0.5 1 1.5 2 2.5 3 3.5 4
IDD (mA)
Internal operating frequency (MHz)
5.5V
4.5V
2
1.5
1
0.5
MC68HC05B6 MOTOROLA
11-5
ELECTRICAL SPECIFICATIONS
11
Figure 11-5 Wait IDD (SM = 1) vs internal operating frequency (4.5V, 5.5V)
Figure 11-6 Increase in IDD vs frequency f or A/D, SCI systems active, VDD = 5.5V
Figure 11-7 IDD vs mode vs internal operating frequency, VDD = 5.5V
0.8
0.7
0.6
0.5
0.4
0.3
0.2
0.1
00 0.5 1 1.5 2 2.5 3 3.5 4
IDD (mA)
Internal operating frequency (MHz)
5.5V
4.5V
0.9
1.4
1.2
1
0.8
0.6
0.4
0.2
00 0.5 1 1.5 2 2.5 3
IDD (mA)
Internal operating frequency (MHz)
A/D + SCI
A/D
1.6
SCI
MOTOROLA
11-6 MC68HC05B6ELECTRICAL SPECIFICATIONS
11
(1) All IDD measurements taken with suitable decoupling capacitors across the power supply to suppress the
transient switching currents inherent in CMOS designs (see Section 2).
(2) Typical values are at mid point of voltage range and at 25C only.
(3) RUN and WAIT IDD: measured using an e xternal square-wave clock source (fOSC = 2.1MHz); all inputs 0.2 V
from rail; no DC loads; maximum load on outputs 50pF (20pF on OSC2).
STOP /WAIT IDD: all ports configured as inputs; VIL = 0.2 V and VIH = VDD – 0.2 V: STOP IDD measured with
OSC1 = VDD.
WAIT IDD is affected linearly by the OSC2 capacitance.
Table 11-4 DC electrical characteristics for 3.3V operation
(VDD = 3.3Vdc  10%, VSS = 0Vdc, TA = TL to TH)
Characteristic(1) Symbol Min Typ(2) Max Unit
Output voltage
ILOAD = – 10 A
ILOAD = +10 A VOH
VOL VDD – 0.1
——
——
0.1 V
Output high voltage (ILOAD = 0.2mA)
PA0–7, PB0–7, PC0–7, TCMP1, TCMP2
Output high voltage (ILOAD = 0.4mA)
TDO, SCLK, PLMA, PLMB
VOH
VOH
VDD – 0.3
VDD – 0.3
VDD – 0.1
VDD – 0.1
—
—V
Output low voltage (ILOAD = 0.4mA)
PA0–7, PB0–7, PC0–7, TCMP1, TCMP2,
TDO, SCLK, PLMA, PLMB
Output low voltage (ILOAD = 0.4mA)
RESET
VOL
VOL
— 0.1
0.2
0.3
0.6 V
Input high voltage
PA0–7, PB0–7, PC0–7, PD0–7, OSC1,
IRQ, RESET, TCAP1, TCAP2, RDI VIH 0.7VDD — VDD V
Input low voltage
PA0–7, PB0–7, PC0–7, OSC1, IRQ,RESET,
TCAP1, TCAP2, RDI VIL VSS — 0.2VDD V
Supply current(3)
RUN (SM = 0) (See Figure 11-2)
RUN (SM = 1) (See Figure 11-3)
WAIT (SM = 0) (See Figure 11-4)
WAIT (SM = 1) (See Figure 11-5)
STOP 0 to 70 (standard)
– 40 to 85 (extended)
– 40 to 105 (extended)
– 40 to 125 (automotive)
IDD
—
—
—
—
—
—
—
—
1.2
0.2
0.4
0.15
1
—
—
—
3
1
1.5
0.5
10
10
40
40
mA
mA
mA
mA
A
A
A
A
High-Z leakage current
PA0–7, PB0–7, PC0–7, TDO, RESET, SCLK IIL — 0.2 1 A
Input current (0 to 70)
IRQ, OSC1, TCAP1, TCAP2, RDI,
PD0/AN0-PD7/AN7 (channel not selected) IIN — 0.2
0.2 1
1 A
Input current (– 40 to 125)
IRQ, OSC1, TCAP1, TCAP2, RDI, IIN — — 5 A
Capacitance
Ports (as input or output),RESET, TDO, SCLK
IRQ, TCAP1, TCAP2, OSC1, RDI
PD0/AN0–PD7/AN7 (A/D off)
PD0/AN0–PD7/AN7 (A/D on)
COUT
CIN
CIN
CIN
—
—
—
—
—
—
12
22
12
8
TBD
TBD
pF
pF
pF
pF
MC68HC05B6 MOTOROLA
11-7
ELECTRICAL SPECIFICATIONS
11
11.3.2 IDD trends for 3.3V operation
Figure 11-8 Run IDD vs internal operating frequency (3V, 3.6V)
Figure 11-9 Run IDD (SM = 1) vs internal operating frequency (3V,3.6V)
Figure 11-10 Wait IDD vs internal operating frequency (3V, 3.6V)
2.5
00 0.5 1 1.5 2 2.5
IDD (mA)
Internal operating frequency (MHz)
3.6V
3.0V
2
1.5
1
0.5
0.6
00 0.5 1 1.5 2 2.5
IDD (mA)
Internal operating frequency (MHz)
3.6V
3.0V
0.5
0.4
0.3
0.2
0.1
1.2
00 0.5 1 1.5 2 2.5
IDD (mA)
Internal operating frequency (MHz)
3.6V
3.0V
1
0.8
0.6
0.4
0.2
MOTOROLA
11-8 MC68HC05B6ELECTRICAL SPECIFICATIONS
11
Figure 11-11 Wait IDD (SM = 1) vs internal operating frequency (3V, 3.6V)
Figure 11-12 Increase in IDD vs frequency f or A/D , SCI systems active, VDD = 3.6V
Figure 11-13 IDD vs mode vs internal operating frequency, VDD = 3.6V
0.5
00 0.5 1 1.5 2 2.5
IDD (mA)
Internal operating frequency (MHz)
3.6V
3.0V
0.4
0.3
0.2
0.1
0.7
0.6
0.5
0.4
0.3
0.2
0.1
00 0.5 1 1.5 2 2.5
IDD (mA)
Internal operating frequency (MHz)
A/D
SCI
A/D + SCI
2.5
2
1.5
1
0.5
00 0.5 1 1.5 2 2.5
IDD (mA)
Internal operating frequency (MHz)
Run IDD
Wait IDD
Run IDD (SM=1)
Wait IDD (SM=1)
MC68HC05B6 MOTOROLA
11-9
ELECTRICAL SPECIFICATIONS
11
11.4 A/D converter characteristics
(1) Performance verified down to 2.5V VR, but accuracy is tested and guaranteed at VR = 5V10%.
(2) Source impedances greater than 10k will adversely affect internal charging time during input sampling.
(3) The external system error caused by input leakage current is approximately equal to the product of R source and input
current. Input current to A/D channel will be dependent on external source impedance (see Figure 8-2).
Table 11-5 A/D characteristics for 5V operation
(VDD = 5.0 Vdc  10%, VSS = 0 Vdc, TA = TL to TH)
Characteristic Parameter Min Max Unit
Resolution Number of bits resolved by the A/D 8 — Bit
Non-linearity Max deviation from the best straight line through the A/D
transfer characteristics
(VRH = VDD and VRL = 0V) —  0.5 LSB
Quantization error Uncertainty due to converter resolution —  0.5 LSB
Absolute accuracy Difference between the actual input voltage and the
full-scale equivalent of the binary code output code for all
errors —  1 LSB
Conversion range Analog input voltage range VRL VRH V
VRH Maximum analog reference voltage VRL VDD + 0.1 V
VRL Minimum analog reference voltage VSS – 0.1 VRH V
VR(1) Minimum difference between VRH and VRL 3 — V
Conversion time Total time to perform a single analog to digital conversion
a. External clock (OSC1, OSC2)
b. Internal RC oscillator —
—32
32 tCYC
s
Monotonicity Conversion result never decreases with an increase in
input voltage and has no missing codes GUARANTEED
Zero input reading Conversion result when VIN = VRL 00 — Hex
Full scale reading Conversion result when VIN = VRH — FF Hex
Sample acquisition time Analog input acquisition sampling
a. External clock (OSC1, OSC2)
b. Internal RC oscillator(2) —
—12
12 tCYC
s
Sample/hold capacitance Input capacitance on PD0/AN0–PD7/AN7 — 12 pF
Input leakage(3) Input leakage on A/D pins PD0/AN0–PD7/AN7, VRL, VRH — 1 A
MOTOROLA
11-10 MC68HC05B6ELECTRICAL SPECIFICATIONS
11
(1) Source impedances greater than 10k will adversely affect internal charging time during input sampling.
(2) The external system error caused by input leakage current is approximately equal to the product of R source and input
current. Input current to A/D channel will be dependent on external source impedance (see Figure 8-2).
Table 11-6 A/D characteristics for 3.3V operation
(VDD = 3.3 Vdc  10%, VSS = 0 Vdc, TA = TL to TH)
Characteristic Parameter Min Max Unit
Resolution Number of bits resolved by the A/D 8 — Bit
Non-linearity Max deviation from the best straight line through the A/D
transfer characteristics
(VRH = VDD and VRL = 0V) —  1 LSB
Quantization error Uncertainty due to converter resolution —  1 LSB
Absolute accuracy Difference between the actual input voltage and the
full-scale equivalent of the binary code output code for all
errors —  2 LSB
Conversion range Analog input voltage range VRL VRH V
VRH Maximum analog reference voltage VRL VDD + 0.1 V
VRL Minimum analog reference voltage VSS – 0.1 VRH V
VRMinimum difference between VRH and VRL 3 — V
Conversion time Total time to perform a single analog to digital conversion
Internal RC oscillator — 32 s
Monotonicity Conversion result never decreases with an increase in
input voltage and has no missing codes GUARANTEED
Zero input reading Conversion result when VIN = VRL 00 — Hex
Full scale reading Conversion result when VIN = VRH — FF Hex
Sample acquisition time Analog input acquisition sampling
Internal RC oscillator(1) — 12 s
Sample/hold capacitance Input capacitance on PD0/AN0–PD7/AN7 — 12 pF
Input leakage(2) Input leakage on A/D pins PD0/AN0–PD7/AN7, VRL, VRH — 1 A
MC68HC05B6 MOTOROLA
11-11
ELECTRICAL SPECIFICATIONS
11
11.5 Control timing
(1) For bus frequencies less than 2 MHz, the internal RC oscillator should be used when
programming the EEPROM.
(2) Since a 2-bit prescaler in the timer must count four external cycles (tcyc), this is the limiting
factor in determining the timer resolution.
(3) The minimum period tTLTL should not be less than the number of cycle times it takes to
execute the capture interrupt service routine plus 24 tcyc.
(4) The minimum period tILIL should not be less than the number of cycle times it takes to
execute the interrupt service routine plus 21 tcyc.
Table 11-7 Control timing for 5V operation
(VDD = 5.0 Vdc  10%, VSS = 0 Vdc, TA = TL to TH)
Characteristic Symbol Min Max Unit
Frequency of operation
Crystal option
External clock option fOSC
fOSC
—
dc 4.2
4.2 MHz
MHz
Internal operating frequency (fOSC/2)
Crystal
External clock fOP
fOP
dc
dc 2.1
2.1 MHz
MHz
Cycle time (see Figure 9-1) tCYC 480 — ns
Crystal oscillator start-up time (see Figure 9-1) tOXOV — 100 ms
Stop recovery start-up time (crystal oscillator) tILCH 100 ms
RC oscillator stabilization time tADRC 100 ms
A/D converter stabilization time tADON 500 s
External RESET input pulse width tRL 1.5 — tCYC
Power-on RESET output pulse width
4064 cycle
16 cycle tPORL
tPORL
4064
16 —
—
tCYC
tCYC
Watchdog RESET output pulse width tDOGL 1.5 — tCYC
Watchdog time-out tDOG 6144 7168 tCYC
EEPROM byte erase time
0 to 70 (standard)
– 40 to 85 (extended)
– 40 to 125 (automotive)
tERA
tERA
tERA
10
10
10
—
—
—
ms
ms
ms
EEPROM byte program time(1)
0 to 70 (standard)
– 40 to 85 (extended)
– 40 to 125 (automotive)
tPROG
tPROG
tPROG
10
10
20
—
—
—
ms
ms
ms
Timer (see Figure 11-14)
Resolution(2)
Input capture pulse width
Input capture pulse period
tRESL
tTH, tTL
tTLTL
4
125
—(3)
—
—
—
tCYC
ns
tCYC
Interrupt pulse width (edge-triggered) tILIH 125 — ns
Interrupt pulse period tILIL —(4) — tCYC
OSC1 pulse width tOH, tOL 90 — ns
MOTOROLA
11-12 MC68HC05B6ELECTRICAL SPECIFICATIONS
11
(1) For bus frequencies less than 2 MHz, the internal RC oscillator should be used when
programming the EEPROM.
(2) Since a 2-bit prescaler in the timer must count four external cycles (tcyc), this is the limiting
factor in determining the timer resolution.
(3) The minimum period tTLTL should not be less than the number of cycle times it takes to
execute the capture interrupt service routine plus 24 tcyc.
(4) The minimum period tILIL should not be less than the number of cycle times it takes to
execute the interrupt service routine plus 21 tcyc.
Table 11-8 Control timing for 3.3V operation
(VDD = 3.3Vdc  10%, VSS = 0 Vdc, TA = TL to TH)
Characteristic Symbol Min Max Unit
Frequency of operation
Crystal option
External clock option fOSC
fOSC
—
dc 2.0
2.0 MHz
MHz
Internal operating frequency (fOSC/2)
Crystal
External clock fOP
fOP
—
dc 1.0
1.0 MHz
MHz
Cycle time (see Figure 9-1) tCYC 1000 — ns
Crystal oscillator start-up time (see Figure 9-1) tOXOV — 100 ms
Stop recovery start-up time (crystal oscillator) tILCH 100 ms
RC oscillator stabilization time tADRC 100 ms
A/D converter stabilization time tADON 500 s
External
RESET input pulse width tRL 1.5 — tCYC
Power-on RESET output pulse width
4064 cycle
16 cycle tPORL
tPORL
4064
16 —
—
tCYC
tCYC
Watchdog RESET output pulse width tDOGL 1.5 — tCYC
Watchdog time-out tDOG 6144 7168 tCYC
EEPROM byte erase time
0 to 70 (standard)
– 40 to 85 (extended)
– 40 to 125 (automotive)
tERA
tERA
tERA
30
30
30
—
—
—
ms
ms
ms
EEPROM byte program time(1)
0 to 70 (standard)
– 40 to 85 (extended)
– 40 to 125 (automotive)
tPROG
tPROG
tPROG
30
30
30
—
—
—
ms
ms
ms
Timer (see Figure 11-14)
Resolution(2)
Input capture pulse width
Input capture pulse period
tRESL
tTH, tTL
tTLTL
4
250
—(3)
—
—
—
tCYC
ns
tCYC
Interrupt pulse width (edge-triggered) tILIH 250 — ns
Interrupt pulse period tILIL —(4) — tCYC
OSC1 pulse width tOH, tOL 200 — ns
MC68HC05B6 MOTOROLA
11-13
ELECTRICAL SPECIFICATIONS
11
Figure 11-14 Timer relationship
External
signal
(TCAP1,
TCAP2)
tTLTL tTH tTL
MOTOROLA
11-14 MC68HC05B6ELECTRICAL SPECIFICATIONS
THIS PAGE INTENTIONALLY LEFT BLANK
11
MC68HC05B6 MOTOROLA
12-1
MECHANICAL DATA
12
12
MECHANICAL DATA
12.1 MC68HC05B6 pin configurations
12.1.1 52-pin plastic leaded chip carrier (PLCC)
Figure 12-1 52-pin PLCC pinout
PC3
PC4
PC5
PC6
PC7
VSS
VPP1
PB0
PB1
PB2
PB3
PB4
PB5
VRH
PD4/AN4
VDD
PD3/AN3
PD2/AN2
PD1/AN1
PD0/AN0
NC
OSC1
OSC2
RESET
IRQ
PLMA
PLMB
TCAP1
TCAP2
PA7
PA6
PA5
PA4
PA3
PA2
PA1
PA0
PB7
PB6
VRL
NC
PD5/AN5
PD6/AN6
PD7/AN7
TCMP1
TCMP2
TDO
SCLK
RDI
PC0
PC1
PC2/ECLK
46
45
44
43
42
41
40
39
38
37
36
35
34
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
7
6
5
4
3
2
52
51
50
49
48
47
MOTOROLA
12-2 MC68HC05B6MECHANICAL DATA
12
12.1.2 64-pin quad flat pack (QFP)
Figure 12-2 64-pin QFP pinout
NC
PB0
NC
VPP1
17
18
20
21
22
23
24
25
26
27
29
30
31
32
19
48
47
45
44
43
42
41
40
39
38
37
36
35
34
33
46
PB6
PB7
NC
PA0
PA1
PA2
PA3
PA4
PA5
PA6
PA7
NC
TCAP2
TCAP1
PLMB D/A
NC
PC1
PC0
NC
NC
NC
NC
RDI
SCLK
TDO
TCMP2
TCMP1
PD7/AN7
PD6/AN6
PD5/AN5
NC
NC
VRL
VRH
VDD
PD3/AN3
PD2/AN2
PD1/AN1
NC
NC
NC
OSC1
OSC2
RESET
IRQ
PLMA D/A
PD4/AN4
PC2/ECLK
PC3
PC5
PC6
PC7
VSS
PB1
PB2
PB3
PB4
PB5
PC4
1
2
4
5
6
7
8
9
10
11
12
13
14
15
16
3
PD0/AN0
28
64
63
61
60
59
58
56
55
54
53
52
51
50
49
62
57
Device Pin 27 Pin 57
MC68HC05B4 NC NC
MC68HC05B6
MC68HC05B8
MC68HC05B16
MC68HC05B32
NC VPP1
MC68HC705B5 Not available in this package
MC68HC705B16 VPP6 VPP1
MC68HC705B32 VPP6 VPP1
MC68HC05B6 MOTOROLA
12-3
MECHANICAL DATA
12
12.1.3 56-pin shrink dual in line package (SDIP)
Figure 12-3 56-pin SDIP pinout
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
TCMP1
PD7
PD6
PD5
NC
NC
NC
VRL
VRH
PD4
VDD
PD3
PD2
PD1
PD0
NC
OSC1
OSC2
RESET
IRQ
PLMA 22
23
24
25
26
27
28
56 TCMP2
TDO
SCLK
RDI
PC0
PC1
NC
PC2
PC3
PC4
PC5
PC6
PC7
VSS
VPP1
PB0
PB1
PB2
PB3
PB4
PB5
55
54
53
52
51
50
49
48
47
46
45
44
43
42
41
40
39
38
37
36
35
34
33
32
31
30
29
PLMB
TCAP1
TCAP2
PA7
PA6
PA5
PA4
NC
PB6
PB7
PA0
PA1
PA2
PA3
Device Pin 16 Pin 42
MC68HC05B4 NC NC
MC68HC05B6 NC VPP1
MC68HC05B8 NC VPP1
MC68HC05B16 NC VPP1
MC68HC05B32 NC VPP1
MC68HC705B5 VPP NC
MC68HC705B32 VPP6 VPP1
MOTOROLA
12-4 MC68HC05B6MECHANICAL DATA
12
12.2 MC68HC05B6 mechanical dimensions
12.2.1 52-pin plastic leaded chip carrier (PLCC)
Figure 12-4 52-pin PLCC mechanical dimensions
–L– –M–
–P–
–N–
pin 1
pin 52
V
W
Y BRK
ZR
A
C
J E
G
G1
U
B
G1
Z1
X
0.10
–T– SEATING PLANE
0.18 T N –P L –M
MS
S S S
Case No. 778-02
52 Lead PLCC
w/o pedestal
Dim. Min. Max. Notes Dim. Min. Max.
A 19.94 20.19
1. Datums –L–, –M–, –N– and –P– are determined where top of lead
shoulder exits plastic body at mould parting line.
2. Dimension G1, true position to be measured at datum –T– (seating
plane).
3. Dimensions R and U do not include mould protrusion. Allowable
mould protrusion is 0.25mm per side.
4. Dimensions and tolerancing per ANSI Y 14.5M, 1982.
5. All dimensions in mm.
U 19.05 19.20
B 19.94 20.19 V 1.07 1.21
C 4.20 4.57 W 1.07 1.21
E 2.29 2.79 X 1.07 1.42
F 0.33 0.48 Y — 0.50
G 1.27 BSC Z 2 10
H 0.66 0.81 G1 18.04 18.54
J 0.51 — K1 1.02 —
K 0.64 — Z1 2 10
R 19.05 19.20
0.18 T L –M N –P
MS
S S S
0.18 T L –M N –P
MSS S S
0.18 T N –P L –M
MS
S S S
0.25 T L –M N –P
SS
S S S
MC68HC05B6 MOTOROLA
12-5
MECHANICAL DATA
12
12.2.2 64-pin quad flat pack (QFP)
Figure 12-5 64-pin QFP mechanical dimensions
64 lead QFP
0.20 MC A – B SDS
L
3348
161
32
17
49
64
- B - B V
0.05 A – B
- D - A
S
0.20 MH A – B SDS
L- A -
Detail “A”
B
B
- A, B, D -
P
Detail “A”
F
N
J
D
Section B–B
Base
Metal
G
H
E
C
-C-
M
Detail “C”
M
-H- Datum
Plane
Seating
Plane
UT
R
Q
K
W
X
Dim. Min. Max. Notes Dim. Min. Max.
A 13.90 14.10 1. Datum Plane –H– is located at bottom of lead and is coincident with
the lead where the lead exits the plastic body at the bottom of the
parting line.
2. Datums A–B and –D to be determined at Datum Plane –H–.
3. Dimensions S and V to be determined at seating plane –C–.
4. Dimensions A and B do not include mould protrusion. Allowable
mould protrusion is 0.25mm per side. Dimensions A and B do
include mould mismatch and are determined at Datum Plane –H–.
5. Dimension D does not include dambar protrusion. Allowable
dambar protrusion shall be 0.08 total in excess of the D dimension
at maximum material condition. Dambar cannot be located on the
lower radius or the foot.
6. Dimensions and tolerancing per ANSI Y 14.5M, 1982.
7. All dimensions in mm.
M 5 10
B 13.90 14.10 N 0.130 0.170
C 2.067 2.457 P 0.40 BSC
D 0.30 0.45 Q 2 8
E 2.00 2.40 R 0.13 0.30
F 0.30 — S 16.20 16.60
G 0.80 BSC T 0.20 REF
H 0.067 0.250 U 9 15
J 0.130 0.230 V 16.20 16.60
K 0.50 0.66 W 0.042 NOM
L 12.00 REF X 1.10 1.30
0.20 MC A – B SDS
0.05 A – B
0.20 MH A – B SDS
0.20 MC A – B SDS
Case No. 840C
MOTOROLA
12-6 MC68HC05B6MECHANICAL DATA
12
12.2.3 56-pin shrink dual in line package (SDIP)
Figure 12-6 56-pin SDIP mechanical dimensions
1 28
56 29
- A -
N
G
DF
L
M
Plane
Seating
C
Dim. Min. Max. Notes Dim. Min. Max.
A 51.69 52.45 1. Due to space limitations, this case shall be represented by a
general case outline, rather than one showing all the leads.
2. Dimensions and tolerancing per ANSI Y 14.5 1982.
3. All dimensions in mm.
4. Dimension L to centre of lead when formed parallel.
5. Dimensions A and B do not include mould flash. Allowable mould
flash is 0.25 mm.
H 7.62 BSC
B 13.72 14.22 J 0.20 0.38
C 3.94 5.08 K 2.92 3.43
D 0.36 0.56 L 15.24 BSC
E 0.89 BSC M 0 15
F 0.81 1.17 N 0.51 1.02
G 1.778 BSC
Case No. 859-01
56 lead SDIP - B - H
K
- T -
0.25 T A
MS
0.25 T B
MS
J
E
MC68HC05B6 MOTOROLA
13-1
ORDERING INFORMATION
13
13
ORDERING INFORMATION
This section describes the information needed to order the MC68HC05B6 and other family members.
To initiate a ROM pattern for the MCU , it is necessary to contact your local field service office, local
sales person or Motorola representative. Please note that you will need to supply details such as:
mask option selections; temperature range; oscillator frequency; package type; electrical test
requirements; and device marking details so that an order can be processed, and a customer
specific part number allocated. Refer to Table 13-1 f or appropriate part numbers. The part number
consists of the device title plus the appropr iate suffix. For example, the MC68HC05B6 in 52-pin
PLCC package at –40 to +85˚C would be ordered as: MC68HC05B6CFN.
Table 13-1 MC order numbers
Device Title Package Type Suffix
0 to 70C Suffix
-40 to +85C Suffix
-40 to +105C Suffix
-40 to +125C
MC68HC05B6 52-pin PLCC FN CFN N/A MFN
64-pin QFP FU CFU N/A MFU
56-pin SDIP B CB N/A MB
MC68HC05B4 52-pin PLCC FN CFN N/A MFN
56-pin SDIP B CB N/A MB
MC68HC05B8 52-pin PLCC FN CFN N/A MFN
64-pin QFP FU CFU N/A MFU
56-pin SDIP B CB N/A MB
MC68HC05B16 52-pin PLCC FN CFN VFN N/A
64-pin QFP FU CFU VFU N/A
56-pin SDIP B CB VB N/A
MC68HC05B32 52-pin PLCC FN N/A VFN N/A
64-pin QFP FU N/A VFU N/A
56-pin SDIP B N/A VB N/A
MC68HC705B5 52-pin PLCC FN CFN VFN MFN
56-pin SDIP B CB VB MB
MC68HC705B16 52-pin PLCC FN CFN VFN N/A
64-pin QFP FU CFU VFU N/A
MC68HC705B32 52-pin PLCC FN N/A VFN N/A
64-pin QFP FU N/A VFU N/A
56-pin SDIP B N/A VB N/A
MOTOROLA
13-2 MC68HC05B6ORDERING INFORMATION
13
13.1 EPROMS
For the MC68HC05B6, an 8 kbyte EPROM programmed with the customer’s software (positive
logic for address and data) should be submitted for pattern generation. All unused bytes should
be programmed to $00. The size of EPROM which should be used for all other f amily members is
listed in Table 13-2.
The EPROM should be clearly labelled, placed in a conductive IC carrier and securely packed.
13.2 Verification media
All original pattern media (EPROMs) are filed for contractual purposes and are not returned. A
computer listing of the ROM code will be generated and retur ned with a listing verification form.
The listing should be thoroughly checked and the verification form completed, signed and returned
to Motorola. The signed verification form constitutes the contractual agreement for creation of the
custom mask. If desired, Motorola will program blank EPROMs (supplied by the customer) from
the data file used to create the custom mask, to aid in the verification process.
13.3 ROM verification units (RVU)
Ten MCUs containing the customer’s ROM pattern will be pro vided for program verification. These
units will have been made using the custom mask but are for ROM verification only. For
expediency, they are usually unmarked and are tested only at room temperature (25C) and at
5 Volts. These RVUs are included in the mask charge and are not production parts. They are
neither backed nor guaranteed by Motorola Quality Assurance.
Table 13-2 EPROMs for pattern generation
Device Size of EPROM
MC68HC05B4 8 kbyte
MC68HC05B8 8 kbyte
MC68HC05B16 16 kbyte
MC68HC05B32 32 kbyte
MC68HC05B6 MOTOROLA
A-1
MC68HC05B4
14
A
MC68HC05B4
The MC68HC05B4 is a device similar to the MC68HC05B6, but without EEPROM and having a
reduced ROM size of 4 kbytes. The entire MC68HC05B6 data sheet applies to the MC68HC05B4,
with the exceptions outlined in this appendix.
Features
• 4158 bytes User ROM (including 14 bytes User vectors)
• No EEPROM
Section 3.5, ‘EEPROM’, therefore, does not apply to the MC68HC05B4, and the register at
address $07 only allows the user to select whether or not the ECLK should appear at PC2, using
bit 3 of $07. All other bits of this register read as ‘0’.
MOTOROLA
A-2 MC68HC05B4MC68HC05B4
14
Figure A-1 MC68HC05B4 block diagram
Port A
PA0
PA1
PA2
PA3
PA4
PA5
PA6
PA7
Port B
PB0
PB1
PB2
PB3
PB4
PB5
PB6
PB7
Port C
PC0
PC1
PC2/ECLK
PC3
PC4
PC5
PC6
PC7
16-bit
programmable
timer
Port D
PD0/AN0
PD1/AN1
PD2/AN2
PD3/AN3
PD4/AN4
PD5/AN5
PD6/AN6
PD7/AN7
Oscillator
176 bytes
RAM
COP watchdog
RESET
IRQ
VDD
VSS
OSC1
OSC2
M68HC05
CPU
SCI
A/D converter
PLM
TCAP1
TCAP2
TCMP1
TCMP2
VRH
VRL
RDI
SCLK
TDO
2 / 32
PLMA D/A
PLMB D/A
8-bit
432 bytes
User ROM
4158 bytes
self check ROM
(including 14 bytes
User vectors)
MC68HC05B6 MOTOROLA
A-3
MC68HC05B4
14
Figure A-2 Memory map of the MC68HC05B4
MOTOROLA
A-4 MC68HC05B4MC68HC05B4
14
(1) This bit is set each time there is a power-on reset.
(2) The state of the WDOG bit after reset is dependent upon the mask option selected; 1=watchdog enabled, 0=watchdog disabled.
Table A-1 Register outline
Register name Address bit 7 bit 6 bit 5 bit 4 bit 3 bit 2 bit 1 bit 0 State on
reset
Port A data (PORTA) $0000 Undefined
Port B data (PORTB) $0001 Undefined
Port C data (PORTC) $0002 PC2/
ECLK Undefined
Port D data (PORTD) $0003 PD7/
AN7 PD6/
AN6 PD5/
AN5 PD4/
AN4 PD3/
AN3 PD2/
AN2 PD1/
AN1 PD0/
AN0 Undefined
Port A data direction (DDRA) $0004 0000 0000
Port B data direction (DDRB) $0005 0000 0000
Port C data direction (DDRC) $0006 0000 0000
ECLK control $0007 0 0 0 0 ECLK 0 0 0 0000 0000
A/D data (ADDATA) $0008 0000 0000
A/D status/control (ADSTAT) $0009 COCO ADRC ADON 0 CH3 CH2 CH1 CH0 0000 0000
Pulse length modulation A (PLMA) $000A 0000 0000
Pulse length modulation B (PLMB) $000B 0000 0000
Miscellaneous $000C POR(1) INTP INTN INTE SFA SFB SM WDOG
(2) ?001 000?
SCI baud rate (BAUD) $000D SPC1 SPC0 SCT1 SCT0 SCT0 SCR2 SCR1 SCR0 00uu uuuu
SCI control 1 (SCCR1) $000E R8 T8
M WAKE CPOL CPHA LBCL uuuu uuuu
SCI control 2 (SCCR2) $000F TIE TCIE RIE ILIE TE RE RWU SBK 0000 0000
SCI status (SCSR) $0010 TDRE TC RDRF IDLE OR NF FE 1100 000u
SCI data (SCDR) $0011 0000 0000
Timer control (TCR) $0012 ICIE OCIE TOIE FOLV2 FOLV1 OLV2 IEDG1 OLVL1 0000 00u0
Timer status (TSR) $0013 ICF1 OCF1 TOF ICF2 OCF2 uuuu uuuu
Input capture high 1 $0014 Undefined
Input capture low 1 $0015 Undefined
Output compare high 1 $0016 Undefined
Output compare low 1 $0017 Undefined
Timer counter high $0018 1111 1111
Timer counter low $0019 1111 1100
Alternate counter high $001A 1111 1111
Alternate counter low $001B 1111 1100
Input capture high 2 $001C Undefined
Input capture low 2 $001D Undefined
Output compare high 2 $001E Undefined
Output compare low 2 $001F Undefined
MC68HC05B6 MOTOROLA
B-1
MC68HC05B8
14
B
MC68HC05B8
The MC68HC05B8 is a device similar to the MC68HC05B6, but with an increased ROM size of
7.25 kbytes. The entire MC68HC05B6 data sheet applies to the MC68HC05B8, with the
exceptions outlined in this appendix.
Features
• 7230 bytes User ROM (including 14 bytes User vectors)
MOTOROLA
B-2 MC68HC05B8MC68HC05B8
14
Figure B-1 MC68HC05B8 block diagram
Port A
PA0
PA1
PA2
PA3
PA4
PA5
PA6
PA7
Port B
PB0
PB1
PB2
PB3
PB4
PB5
PB6
PB7
Port C
PC0
PC1
PC2/ECLK
PC3
PC4
PC5
PC6
PC7
16-bit
programmable
timer
Port D
PD0/AN0
PD1/AN1
PD2/AN2
PD3/AN3
PD4/AN4
PD5/AN5
PD6/AN6
PD7/AN7
Oscillator
176 bytes
RAM
COP watchdog
RESET
IRQ
VDD
VSS
OSC1
OSC2
M68HC05
CPU
SCI
A/D converter
PLM
TCAP1
TCAP2
TCMP1
TCMP2
VRH
VRL
RDI
SCLK
TDO
VPP1
256 bytes
EEPROM
Charge pump
2 / 32
PLMA D/A
PLMB D/A
8-bit
432 bytes
User ROM
7230 bytes
self check ROM
(including 14 bytes
User vectors)
MC68HC05B6 MOTOROLA
B-3
MC68HC05B8
14
Figure B-2 Memory map of the MC68HC05B8
MOTOROLA
B-4 MC68HC05B8MC68HC05B8
14
(1) This bit is set each time there is a power-on reset.
(2) The state of the WDOG bit after reset is dependent upon the mask option selected; 1=watchdog enabled, 0=watchdog disabled.
(3) This register is implemented in EEPROM; therefore reset has no effect on the individual bits.
Table B-1 Register outline
Register name Address bit 7 bit 6 bit 5 bit 4 bit 3 bit 2 bit 1 bit 0 State on
reset
Port A data (PORTA) $0000 Undefined
Port B data (PORTB) $0001 Undefined
Port C data (PORTC) $0002 PC2/
ECLK Undefined
Port D data (PORTD) $0003 PD7 PD6 PD5 PD4 PD3 PD2 PD1 PD0 Undefined
Port A data direction (DDRA) $0004 0000 0000
Port B data direction (DDRB) $0005 0000 0000
Port C data direction (DDRC) $0006 0000 0000
EEPROM/ECLK control $0007 0 0 0 0 ECLK E1ERA E1LAT E1PGM 0000 0000
A/D data (ADDATA) $0008 0000 0000
A/D status/control (ADSTAT) $0009 COCO ADRC ADON 0 CH3 CH2 CH1 CH0 0000 0000
Pulse length modulation A (PLMA) $000A 0000 0000
Pulse length modulation B (PLMB) $000B 0000 0000
Miscellaneous $000C POR(1) INTP INTN INTE SFA SFB SM WDOG(2) ?001 000?
SCI baud rate (BAUD) $000D SPC1 SPC0 SCT1 SCT0 SCT0 SCR2 SCR1 SCR0 00uu uuuu
SCI control 1 (SCCR1) $000E R8 T8
M WAKE CPOL CPHA LBCL Undefined
SCI control 2 (SCCR2) $000F TIE TCIE RIE ILIE TE RE RWU SBK 0000 0000
SCI status (SCSR) $0010 TDRE TC RDRF IDLE OR NF FE 1100 000u
SCI data (SCDR) $0011 0000 0000
Timer control (TCR) $0012 ICIE OCIE TOIE FOLV2 FOLV1 OLV2 IEDG1 OLVL1 0000 00u0
Timer status (TSR) $0013 ICF1 OCF1 TOF ICF2 OCF2 Undefined
Input capture high 1 $0014 Undefined
Input capture low 1 $0015 Undefined
Output compare high 1 $0016 Undefined
Output compare low 1 $0017 Undefined
Timer counter high $0018 1111 1111
Timer counter low $0019 1111 1100
Alternate counter high $001A 1111 1111
Alternate counter low $001B 1111 1100
Input capture high 2 $001C Undefined
Input capture low 2 $001D Undefined
Output compare high 2 $001E Undefined
Output compare low 2 $001F Undefined
Options (OPTR)(3) $0100 EE1P SEC Not affected
MC68HC05B6 MOTOROLA
C-1
MC68HC705B5
14
C
MC68HC705B5
The MC68HC705B5 is a de vice similar to the MC68HC05B6, b ut with the 6 kb ytes ROM and 256
bytes EEPROM replaced by a single EPROM array. In addition, the self-check routines available
on the MC68HC05B6 are replaced by bootstrap firmware. The MC68HC705B5 is intended to
operate as a one time programmable (OTP) version of the MC68HC05B6 or the MC68HC05B4,
meaning that the application program can never be erased once it has been loaded into the
EPROM. The entire MC68HC05B6 data sheet applies to the MC68HC705B5, with the e xceptions
outlined in this appendix.
Features
• 6206 bytes EPROM (including 14 bytes User vectors)
• No EEPROM
• Bootstrap firmware
• Simultaneous programming of up to 4 bytes
• Data protection for program code
• Optional pull-down resistors on port B and port C
• Additional temperature range available; -40 to +105C
• MC68HC05B6 mask options are programmable using control bits held in the options
register
MOTOROLA
C-2 MC68HC05B6MC68HC705B5
14
Figure C-1 MC68HC705B5 block diagram
Port A
PA0
PA1
PA2
PA3
PA4
PA5
PA6
PA7
Port B
PB0
PB1
PB2
PB3
PB4
PB5
PB6
PB7
Port C
PC0
PC1
PC2/ECLK
PC3
PC4
PC5
PC6
PC7
16-bit
programmable
timer
Port D
PD0/AN0
PD1/AN1
PD2/AN2
PD3/AN3
PD4/AN4
PD5/AN5
PD6/AN6
PD7/AN7
Oscillator
176 bytes
RAM
COP watchdog
RESET
IRQ
VDD
VSS
OSC1
OSC2
M68HC05
CPU
SCI
A/D converter
PLM
TCAP1
TCAP2
TCMP1
TCMP2
VRH
VRL
RDI
SCLK
TDO
VPP6
256 bytes
EPROM1
6206 bytes
2 / 32
PLMA D/A
PLMB D/A
8-bit
496 bytes
bootstrap ROM
EPROM
(including 14 bytes
User vectors)
MC68HC05B6 MOTOROLA
C-3
MC68HC705B5
14
Figure C-2 Memory map of the MC68HC705B5
MOTOROLA
C-4 MC68HC05B6MC68HC705B5
14
(1) This bit reflects the state of the EPP bit in the options register ($1EFE) at reset.
(2) This bit is set each time the device is powered-on.
(3) The state of the WDOG bit after reset depends on the mask option selected; ‘1’ = watchdog enabled and ‘0’ = watchdog disabled.
(4) Because this register is implemented in EPROM, reset has no effect on the state of the individual bits.
Table C-1 Register outline
Register name Address bit 7 bit 6 bit 5 bit 4 bit 3 bit 2 bit 1 bit 0 State on
reset
Port A data (PORTA) $0000 Undefined
Port B data (PORTB) $0001 Undefined
Port C data (PORTC) $0002 PC2/
ECLK Undefined
Port D data (PORTD) $0003 PD7 PD6 PD5 PD4 PD3 PD2 PD1 PD0 Undefined
Port A data direction (DDRA) $0004 0000 0000
Port B data direction (DDRB) $0005 0000 0000
Port C data direction (DDRC) $0006 0000 0000
EPROM/ECLK control $0007
EPPT(1) ELAT EPGM ECLK u?00 0uuu
A/D data (ADDATA) $0008 0000 0000
A/D status/control (ADSTAT) $0009 COCO ADRC ADON 0 CH3 CH2 CH1 CH0 0000 0000
Pulse length modulation A (PLMA) $000A 0000 0000
Pulse length modulation B (PLMB) $000B 0000 0000
Miscellaneous $000C POR(2) INTP INTN INTE SFA SFB SM WDOG(3) ?001 000?
SCI baud rate (BAUD) $000D SPC1 SPC0 SCT1 SCT0 SCT0 SCR2 SCR1 SCR0 00uu uuuu
SCI control 1 (SCCR1) $000E R8 T8 M WAKE CPOL CPHA LBCL uuuu
SCI control 2 (SCCR2) $000F TIE TCIE RIE ILIE TE RE RWU SBK 0000 0000
SCI status (SCSR) $0010 TDRE TC RDRF IDLE OR NF FE 1100 000u
SCI data (SCDR) $0011 0000 0000
Timer control (TCR) $0012 ICIE OCIE TOIE FOLV2 FOLV1 OLV2 IEDG1 OLVL1 0000 00u0
Timer status (TSR) $0013 ICF1 OCF1 TOF ICF2 OCF2 uuuu
Input capture high 1 $0014 Undefined
Input capture low 1 $0015 Undefined
Output compare high 1 $0016 Undefined
Output compare low 1 $0017 Undefined
Timer counter high $0018 1111 1111
Timer counter low $0019 1111 1100
Alternate counter high $001A 1111 1111
Alternate counter low $001B 1111 1100
Input capture high 2 $001C Undefined
Input capture low 2 $001D Undefined
Output compare high 2 $001E Undefined
Output compare low 2 $001F Undefined
Options (OPTR)(4) $1EFE EPP 0 RTIM RWAT WWAT PBPD PCPD Not affected
MC68HC05B6 MOTOROLA
C-5
MC68HC705B5
14
C.1 EPROM
The MC68HC705B5 has a total of 6206 bytes of EPROM, 256 bytes being reserved for the
EPROM1 array (see Figure C-2). The EPP bit (EPROM protect) is not operative on the EPROM1
array, making it possible to program it after the main EPROM has been programmed and
protected. The reset and interrupt vectors are located at $1FF2-$1FFF and the EPROM control
register described in Section C.2.1 is located at address $0007.
The EPROM array is supplied by the VPP6 pin in both read and programming modes. Typically
the user’s software will be loaded in a programming board where VPP6 is controlled by one of the
bootstrap loader routines (bootloader mode). It will then be placed in an application where no
programming occurs (user mode). In this case the VPP6 pin should be hardwired to VDD.
An erased EPROM byte reads as $00.
Warning: A minimum VDD voltage must be applied to the VPP6 pin at all times, including
power-on, as a lower voltage could damage the device.
C.1.1 EPROM programming operation
The User program can be used to program some EPROM locations, provided the proper
procedure is followed. In particular, the programming sequence must be running in RAM, as the
EPROM will not be a vailable f or code execution while the ELAT bit is set. The VPP6 s witching must
occur externally, after the EPGM bit is set, for example, under the control of a signal generated on
a pin by the programming routine.
Note:
When the part becomes a PR OM, only the cumulative programming of bits to logic 1 is
possible if multiple programming is made on the same byte.
To allow simultaneous programming of up to 4 b ytes, they must be in the same g roup of addresses
which share the same most significant address bits; only the two LSBs can change.
MOTOROLA
C-6 MC68HC05B6MC68HC705B5
14
C.2 EPROM registers
C.2.1 EPROM control register
Bit 7 — Factory use only
This bit is strictly for factory use only and will always read zero.
EPPT — EPROM protect test bit
This bit is a cop y of the EPROM protect bit (EPP) located in the option register. When ELAT is set,
the EPPT bit can be tested by the software to check if the EPROM array is protected or not, since
the EPROM content is not available when ELAT is set.
POR or external reset modifies this bit to reflect the state of the EPP bit in the options register.
ELAT — EPROM programming latch enable bit
1 (set) – When set, this bit allows latching of the address and up to 4 data
bytes for further programming, provided EPGM is zero.
0 (clear) – When cleared, program and interrupt routines can be executed and
data can be read in the EPROM or firmware ROM.
STOP, power-on and external reset clear this bit.
EPGM — EPROM programming bit
This bit is the EPROM program enable bit. It can be set to ‘1’ to enable programming only after
ELAT is set and at least one byte is written to the EPROM. It is not possible to clear EPGM by
software, but clearing ELAT will always clear EPGM.
ECLK — External clock option bit
See Section 4.3.
(1) This bit is a copy of the EPP bit in the options register at $1EFE and therefore its state on reset will be the same as that for the
EPP bit.
Address bit 7 bit 6 bit 5 bit 4 bit 3 bit 2 bit 1 bit 0 State
on reset
EPROM/ECLK control $0007
EPPT(1) ELAT EPGM ECLK u?00 0uuu
MC68HC05B6 MOTOROLA
C-7
MC68HC705B5
14
C.3 Options register (OPTR)
Note:
This register can only be written to while the device is in bootloader mode.
Bit 7 — Factory use only
Warning: This bit is strictly for factory use only and will always read zero to avoid accidental
damage to the device. Any attempt to write to this bit could result in physical damage.
EPP — EPROM protect
This bit protects the contents of the main EPROM against accidental modification; it has no effect
on reading or executing code in the EPROM.
1 (set) – EPROM contents are protected.
0 (clear) – EPROM contents are not protected.
RTIM — Reset time
This bit can modify tPORL, i.e. the time that the RESET pin is kept low following a power-on reset.
This feature is handled in the ROM part via a mask option.
1 (set) – tPORL = 16 cycles.
0 (clear) – tPORL = 4064 cycles.
RWAT — Watchdog after reset
This bit can modify the status of the watchdog counter after reset.
1 (set) – The watchdog will be active immediately following power-om or
external reset (except in bootstrap mode).
0 (clear) – The watchdog system will be disabled after power-on or external
reset.
WWAT — Watchdog during WAIT mode
This bit can modify the status of the watchdog counter during WAIT mode.
(1) This register is implemented in EPROM, therefore reset has no effect on the state of the individual bits.
Address bit 7 bit 6 bit 5 bit 4 bit 3 bit 2 bit 1 bit 0 State
on reset
Options (OPTR)(1) $1EFE
EPP 0 RTIM RWAT WWAT PBPD PCPD Not affected
MOTOROLA
C-8 MC68HC05B6MC68HC705B5
14
1 (set) – The watchdog will be active during WAIT mode.
0 (clear) – The watchdog system will be disabled during WAIT mode.
PBPD – Port B pull-down resistors
1 (set) – Pull-down resistors are connected to all 8 pins of port B; the
pull-down, RPD, is active only while the pin is an input.
0 (clear) – No pull-down resistors are connected.
PCPD — Port C pull-down resistors
1 (set) – Pull-down resistors are connected to all 8 pins of port C; the
pull-down, RPD, is active only while the pin is an input.
0 (clear) – No pull-down resistors are connected.
The combination of bit 0 and bit 1 allows the option of pull-do wn resistors on 0, 8 or 16 inputs. This
feature is not available on the MC68HC05B6.
C.4 Bootstrap mode
The 432 bytes of self-check firmware on the MC68HC05B6 are replaced with 496 bytes of
bootstrap firmware. The bootstrap firmware located from $0200 to $02FF and $1F00 to $1FEF
can be used to program the EPROM, to check if the EPROM is erased and to load and execute
data in RAM.
When the MC68HC705B5 is placed in the bootstrap mode, the bootstrap reset vector is fetched
and the bootstrap firmware starts to execute. Table C-2 shows the conditions required to enter
each level of bootstrap mode on the rising edge of RESET. The hold time on the IRQ and TCAP1
pins after the external RESET pin is brought high is two clock cycles.
Table C-2 Mode of operation selection
IRQ pin TCAP1 pin PD2 PD3 PD4 Mode
VSS to VDD VSS to VDD x x x Single chip
+ 9 Volts VDD 0 1 0 Erased EPROM verification
+ 9 Volts VDD x 0 0 EPROM parallel bootstrap load
+ 9 Volts VDD x 1 1 EPROM (RAM) serial bootstrap load and execute
+ 9 Volts VDD x 0 1 RAM parallel bootstrap load and execute
x = Don’t care
MC68HC05B6 MOTOROLA
C-9
MC68HC705B5
14
The bootstrap program first copies part of itself into RAM, as the program cannot be executed in
ROM during verification/programming of the EPROM. It then sets the TCMP1 output to a logic
high level.
Figure C-3 Modes of operation flow chart (1 of 2)
TCAP1 set?
IRQ at 9V?
EPROM
erased?
PD2 set?PD3 set?
PD4 set?
Reset
Program EPROM;
parallel load;
green LED flashes
Programming OK?
User mode
Red LED on
Green LED on
Non-user mode
Red LED on Green LED on
Non-user mode
A
Y
Y
Y
Y
Y Y
N
N
N
NN
N
Y
Bootstrap mode
EPROM not erased
EPROM verified
Parallel EPROM bootstrap
Bad EPROM programming
N
MOTOROLA
C-10 MC68HC05B6MC68HC705B5
14
Figure C-4 Modes of operation flow chart (2 of 2)
Programming OK?
Negative
address?
PD4 set?
PD3 set?
Transmit last four
programmed locations
A
Red LED off
Receive address
Receive four data
Execute RAM
program at $0083
Green LED on
Load next RAM
byte
RAM full?
Execute RAM
program at $0050
Program EPROM data
at address; green LED
flashes
Red LED on
N
Y
Y
Y
Y
Y
N
N
N
Serial EPROM (RAM) bootstrap
Bad EPROM
Bootstrap RAM
programming
N
MC68HC05B6 MOTOROLA
C-11
MC68HC705B5
14
C.4.1 Erased EPROM verification
The flowchart in Figure C-3 and Figure C-4 shows that the on-chip bootstrap routines can be used
to check if the EPROM is erased (all $00s). If a non $00 byte is detected, the red LED stays on
and the routine will stay in a loop. Only when the whole EPROM content is verified as erased will
the green LED be turned on.
C.4.2 EPROM parallel bootstrap load
When this mode is selected, the EPROM is loaded in increasing address order with non EPROM
segments being skipped by the loader. Simultaneous programming is performed by reading four
bytes of data bef ore actual programming is performed, thus dividing the loading time of the internal
EPROM by four.
When PD2=0, the programming time is set to 5 milliseconds and the program/verify routine takes
approximately 15 seconds.
Parallel data is entered through Port A, while the 13-bit address is output on por t B and PC0 to
PC4. If the data comes from an external EPROM, the handshake can be disabled by connecting
together PC5 and PC6. If the data is supplied via a parallel interface, handshaking will be pro vided
by PC5 and PC6 according to the timing diagram of Figure C-5.
During programming, the green LED flashes at about 3 Hz.
Upon completion of the programming operation, the EPROM content is checked against the
external data source. If programming is v erified the green LED stays on, while an error causes the
red LED to be turned on. Figure C-6 shows a circuit that can be used to program the EPROM (or
to load and execute data in the RAM).
Note:
The entire EPROM can be loaded from the external source; if it is desired to leave a
segment undisturbed, the data for this segment should be all zeros.
Figure C-5 Timing diagram with handshake
Data read Data read
Address
HDSK out
(PC5)
DATA
HDSK in
(PC6)
F29
MOTOROLA
C-12 MC68HC05B6MC68HC705B5
14
Figure C-6 EPROM(RAM) parallel bootstrap schematic diagram
PB0
PB1
PB2
PB3
PB4
PB5
PB6
PB7
PA0
PA1
PA2
PA3
PA4
PA5
PA6
PA7
VDD
OSC1
OSC2
TCAP1
IRQ
RESET
VSS
A0
A1
A2
A3
A4
A5
A6
A7
D0
D1
D2
D3
D4
D5
D6
D7
GND OE
VCCPGMVPP
14 22
10
9
8
7
6
5
4
1 26 27 28
12
13
15
16
17
18
19
11
3
+5V
1
2
P1 GND
+5V
100F
22pF 4.0 MHz
1N914
1k
1.0F
22pF
10M
100k
1N914
RESET RUN
0.01F
TDO
SCLK
RDI
VRL
TCAP2
PD7
PD6
PD5
PD3
PD2
PD1
PD0
PD4
+5V
3VPP
VPP6
PC7
PC5
PC4
PC3
PC2
PC1
PC0
PC6
NC
24
21
23
2
A9
A8
A10
A12
CE
A11
A12
A11
A10
A9
A8
HDSK out
HDSK in
Short circuit if
handshake not used
100 k
NC
TCMP1
TCMP2
PLMA
PLMB
470
470
red LED
green LED
4k7
4k7
12 k
BC239C
BC309C
10k 
27C64
+
+
VRH
red LED — programming failed
green LED — programming OK
25
1nF
1N5819
1 k
+
RAM
EPROM
47F +
20
MC68HC705B5
MC68HC05B6 MOTOROLA
C-13
MC68HC705B5
14
C.4.3 EPROM (RAM) serial bootstrap load and execute
The serial routine communicates through the SCI with an external host, typically a PC, by means
of an RS232 link at 9600 baud, 8-bit, no parity and full duplex.
Data format is not ASCII, but 8-bit binary, so a complementar y program must be run by the host
to supply the required format. Such a program is available for the IBM PC from Motorola.
The EPROM bootstrap routines are used to customise the OTP EPROM. To increase the speed
of programming, four bytes are programmed in parallel while the data is simultaneously
transmitted and received in full duplex. This implies that while 4 b ytes are being prog rammed, the
next 4 bytes are received and the preceding 4 b ytes are echoed. The format accepted by the serial
loader is as follows:
[address n high] [address n low] [data(n)] [data (n+1)] [data (n+2)] [data (n+3)]
Address n must have the two LSBs at zero so that n, n+1, n+2 and n+3 have identical MSBs.
These blocks of f our bytes do not need to be contiguous, as a new address is transmitted for each
new group.
The protocol is as follows:
1The MC68HC705B5 sends the last two bytes programmed to the host as a
prompt; this allows verification by the host of proper programming.
2 In response to the first byte prompt, the host sends the first address byte.
3 After receiving the first address byte, the MC68HC705B5 sends the next
byte programmed.
4 The exchange of data continues until the MC68HC705B5 has sent the four
data bytes and the host has sent the 2 address data bytes and 4 data b ytes.
5 If the data is non zero, it is programmed at the address provided, while the
next address and bytes are received and the previous data is echoed.
6 Loop to 1.
After reset, the MC68HC705B5 serial bootstrap routine will first echo two blocks of four bytes at
$0000, as no data is programmed yet.
If the data sent in is $00, no programming in the EPROM takes place, and the contents of the
accessed location are returned as a prompt. The entire EPROM memory can be read in this
fashion (serial dump). The red LED will be on if the data read from the EPROM is not $00.
Serial RAM loading and execute can be accomplished in this mode. A RAM byte will be written if
the address sent by the host in the serial protocol points to the RAM.
In the RAM bootloader mode, all interrupt vectors are mapped to pseudo-vectors in RAM (see
Table C-3). This allows programmers to use their own service-routine addresses. Each
pseudo-vector is allowed three bytes of space rather than the two bytes for normal vectors,
because an explicit jump (JMP) opcode is needed to cause the desired jump to the user’s
service-routine address.
MOTOROLA
C-14 MC68HC05B6MC68HC705B5
14
A 10-byte stack is also reserved at the top of the RAM allo wing, for example, one interrupt and two
sub-routine levels.
Program execution is triggered by sending a negative (bit 7 set) high address; execution starts at
address XADR ($0083).
The RAM addresses between $0050 and $0082 are used by the loader and are therefore not
available to the user during serial loading/executing.
Refer to Figure C-7 shows a suitable circuit. Figure C-9 shows address and data bus timing.
C.4.4 RAM parallel bootstrap load and execute
The RAM bootstrap program will star t loading the RAM with external data (e.g. from a 2564 or
2764 EPROM). Bef ore loading a new byte, the state of the PD4/AN4 pin is checked; if this pin goes
to level ‘0’, or if the RAM is full, then control is given to the loaded program at address $0050.
If the data is supplied by a parallel interface, handshaking will be provided by PC5 and PC6
according to Figure C-10. If the data comes from an external EPROM, the handshake can be
disabled by connecting together PC5 and PC6.
Figure C-8 shows a circuit that can be used to load the RAM with short test programs. Up to 8
programs can be loaded in turn from the EPROM. Selection is accomplished by means of the
switches connected to the EPROM higher address lines (A8 through A10). If the user program
sets PC0 to le vel ‘1’, the external EPROM will be disabled, rendering both port A outputs and port
B inputs available.
The EPROM parallel bootstrap loader circuit (Figure C-6) can also be used, provided VPP is tied
to VDD. The high order address lines will be at zero. The LEDs will stay off.
Table C-3 Bootstrap vector targets in RAM
Vector targets in RAM
SCI interrupt $00E4
Timer overflow $00E7
Timer output compare $00EA
Timer input capture $00ED
IRQ $00F0
SWI $00F3
MC68HC05B6 MOTOROLA
C-15
MC68HC705B5
14
Figure C-7 EPROM (RAM) serial bootstrap schematic diagram
Red — programming error
Green — programming OK
40
VPP6
PC7
PB0
PB1
PB2
PB3
PB4
PB5
PB6
PB7
PA0
PA1
PA2
PA3
PA4
PA5
PA6
PA7
VDD
OSC1
OSC2
TCAP1
IRQ
RESET
VSS
1
2
P1 GND
+5V
1N914
1k
1.0F
100k
1N914
RESET RUN
0.01F
3VPP
PC5
PC4
PC3
PC2
PC1
PC0
PC6
PLMA
PLMB
470
470
Red LED
Green LED
+
+
VRH
22F
22F
22F
2 x 3K 1
23
4
8
6
7
5
11
1213
14
15
16
53
2
1
22F
RS232
Connector MAX
232
+5V
9600 BD
8-bit
no parity
19
18
20
21
50
52
39
38
37
36
35
34
33
32
31
30
29
28
27
26
25
24
14
13
12
5
43
44
45
46
47
48
49
23
2
1
51
22 8 10
41 7
VRL
TCAP2
TCMP1
TCMP2
SCLK
NC
10nF 47F
PD0
PD4
PD1
PD2
PD5
PD6
PD7
+
+
+
+
22pF 4.0 MHz
22pF
10M
4k7
4k7
12 k
BC239C
BC309C
10k 
1nF
1N5819
1 k
+
Serial boot
Erase check
47F +
PD3
4
RDI
TDO
Erase check
Red — EPROM not erased
Green — EPROM erased
Serial boot
MC68HC705B5
3
MOTOROLA
C-16 MC68HC05B6MC68HC705B5
14
Figure C-8 RAM parallel bootstrap schematic diagram
PB0
PB1
PB2
PB3
PB4
PB5
PB6
PB6
PB7
PA0
PA1
PA2
PA3
PA4
PA5
PA6
PA7
VDD
TCAP2
TCMP2
TCMP1
PLMB
PLMA
SCLK
TDO
RDI
VRH
VRL
PD7
PD6
PD5
PD3
PD2
PD1
PD0
PC7
PC6
PC5
PC4
PC3
PC2
PC1
PC0
NC
OSC1
OSC2
TCAP1
IRQ
RESET
PD4
VPP6
VSS
A0
A1
A2
A3
A4
A5
A6
A7
D0
D1
D2
D3
D4
D5
D6
D7
GND OE
A8
A9
A10
A11
A12
CE
VCCPGMVPP
20
2
25
24
23
14 22
10
9
8
7
6
5
4
1 26 27 28
21
12
13
15
16
17
18
19
11
3
+5V
3 x 4.7k
+5V+5V
16 x 100k
1
2
P1 GND
+5V
100F
22pF 4.0 MHz
1N914
1k
1.0F
22pF
10M
100k
1N914
RESET RUN
0.01F
U1
2764
+5V 18 x 100 k
+
+
NC
MC68HC705B5
MC68HC05B6 MOTOROLA
C-17
MC68HC705B5
14
C.4.5 Bootstrap loader timing diagrams
Figure C-9 EPROM parallel bootstrap loader timing diagram
tCOOE
tADE tDHE
Address
Data
tADE tDHE
tADE tDHE
tADE tDHE
tCOOE tCOOE tCDDE
tADE max (address to data delay) 5 machine cycles
tDHA min (data hold time) 14 machine cycles
tCOOE (load cycle time) 117 machine cycles < tCOOE < 150 machine cycles
tCDDE (programming cycle time) tCOOE + tPROG (5ms nominal)
1 machine cycle = 1/(2f0(Xtal))
MOTOROLA
C-18 MC68HC05B6MC68HC705B5
14
Figure C-10 RAM parallel loader timing diagram
tADR tDHR
Address
Data
tCR
PD4 tEXR max
tHO
tHI max
PC5 out
PC6 in
tADR max (address to data delay; PC6=PC5) 16 machine cycles
tDHR min (data hold time) 4 machine cycles
tCR (load cycle time; PC6=PC5) 49 machine cycles
tHO (PC5 handshake out delay) 5 machine cycles
tHI max (PC6 handshake in, data hold time) 10 machine cycles
tEXR max (max delay for transition to be
recognised during this cycle; PC6=PC5 30 machine cycles
1 machine cycle = 1/(2f0(Xtal))
MC68HC05B6 MOTOROLA
C-19
MC68HC705B5
14
C.5 DC electrical characteristics
Note:
The complete table of DC electrical characteristics can be found in Section 11.3. The
values contained in the f ollowing table should be used in conjunction with those quoted
in that section.
C.6 Control timing
Note:
The complete table of control timing can be found in Section 11.5. The values
contained in the f ollowing table should be used in conjunction with those quoted in that
section.
Table C-4 Additional DC electrical characteristics for MC68HC705B5
(VDD = 5 Vdc  10%, VSS = 0 Vdc, TA = 25C)
Characteristic Symbol Min Typ Max Unit
Input current
Port B and port C pull-down (VIN=VIH)IRPD 80 A
EPROM absolute maximum voltage VPP6 max VDD — 18 V
EPROM programming voltage VPP6 15.0 15.5 16 V
EPROM programming current IPP6 — — 18 mA
EPROM read voltage VPP6R VDD VDD VDD V
Table C-5 Additional control timing for MC68HC705B5
(VDD = 5 Vdc  10%, VSS = 0 Vdc, TA = 25 C)
Characteristic Symbol Min Typ Max Unit
EPROM programming time tPROG 5 — 20 ms
MOTOROLA
C-20 MC68HC05B6MC68HC705B5
THIS PAGE INTENTIONALLY LEFT BLANK
14
MC68HC05B6 MOTOROLA
D-1
MC68HC05B16
14
D
MC68HC05B16
The MC68HC05B16 is a device similar to the MC68HC05B6, but with increased RAM, ROM and
self-check ROM sizes. The entire MC68HC05B6 data sheet, including the electrical
characteristics, applies to the MC68HC05B16, with the exceptions outlined in this appendix.
Features
• 15 kbytes User ROM
• 352 bytes of RAM
• 496 bytes self-check ROM
• 52-pin PLCC, 56-pin SDIP and 64-pin QFP packages
D.1 Self-check routines
The self-check routines for the MC68HC05B16 are identical to those of the MC68HC05B6 with
the following exception.
The count byte on the MC68HC05B16 can be any value up to 256 ($00). The first 176 bytes are
loaded into RAM I and the remainder is loaded into RAM II starting at $0250.
MOTOROLA
D-2 MC68HC05B16MC68HC05B16
14
Figure D-1 MC68HC05B16 block diagram
Port A
PA0
PA1
PA2
PA3
PA4
PA5
PA6
PA7
Port B
PB0
PB1
PB2
PB3
PB4
PB5
PB6
PB7
Port C
PC0
PC1
PC2/ECLK
PC3
PC4
PC5
PC6
PC7
16-bit
timer
Port D
PD0/AN0
PD1/AN1
PD2/AN2
PD3/AN3
PD4/AN4
PD5/AN5
PD6/AN6
PD7/AN7
Oscillator
COP watchdog
RESET
IRQ
VDD
VSS
OSC1
OSC2
M68HC05
CPU
SCI
A/D converter
PLM
TCAP1
TCAP2
TCMP1
TCMP2
VRH
VRL
RDI
SCLK
TDO
VPP1
256 bytes
EEPROM
Charge pump
2 / 32
PLMA D/A
PLMB D/A
8-bit
15120 bytes
ROM
352 bytes
static RAM
496 bytes
self-check ROM
MC68HC05B6 MOTOROLA
D-3
MC68HC05B16
14
Figure D-2 Memory map of the MC68HC05B16
MOTOROLA
D-4 MC68HC05B16MC68HC05B16
14
(1) This bit is set each time there is a power-on reset.
(2) The state of the WDOG bit after reset is dependent upon the mask option selected; 1=watchdog enabled, 0=watchdog disabled.
(3) This register is implemented in EEPROM; therefore reset has no effect on the individual bits.
Table D-1 Register outline
Register name Address bit 7 bit 6 bit 5 bit 4 bit 3 bit 2 bit 1 bit 0 State on
reset
Port A data (PORTA) $0000 Undefined
Port B data (PORTB) $0001 Undefined
Port C data (PORTC) $0002 PC2/
ECLK Undefined
Port D data (PORTD) $0003 PD7 PD6 PD5 PD4 PD3 PD2 PD1 PD0 Undefined
Port A data direction (DDRA) $0004 0000 0000
Port B data direction (DDRB) $0005 0000 0000
Port C data direction (DDRC) $0006 0000 0000
EEPROM/ECLK control $0007 0 0 0 0 ECLK E1ERA E1LAT E1PGM 0000 0000
A/D data (ADDATA) $0008 0000 0000
A/D status/control (ADSTAT) $0009 COCO ADRC ADON 0 CH3 CH2 CH1 CH0 0000 0000
Pulse length modulation A (PLMA) $000A 0000 0000
Pulse length modulation B (PLMB) $000B 0000 0000
Miscellaneous $000C POR(1) INTP INTN INTE SFA SFB SM WDOG(2) ?001 000?
SCI baud rate (BAUD) $000D SPC1 SPC0 SCT1 SCT0 SCT0 SCR2 SCR1 SCR0 00uu uuuu
SCI control 1 (SCCR1) $000E R8 T8
M WAKE CPOL CPHA LBCL Undefined
SCI control 2 (SCCR2) $000F TIE TCIE RIE ILIE TE RE RWU SBK 0000 0000
SCI status (SCSR) $0010 TDRE TC RDRF IDLE OR NF FE 1100 000u
SCI data (SCDR) $0011 0000 0000
Timer control (TCR) $0012 ICIE OCIE TOIE FOLV2 FOLV1 OLV2 IEDG1 OLVL1 0000 00u0
Timer status (TSR) $0013 ICF1 OCF1 TOF ICF2 OCF2 Undefined
Input capture high 1 $0014 Undefined
Input capture low 1 $0015 Undefined
Output compare high 1 $0016 Undefined
Output compare low 1 $0017 Undefined
Timer counter high $0018 1111 1111
Timer counter low $0019 1111 1100
Alternate counter high $001A 1111 1111
Alternate counter low $001B 1111 1100
Input capture high 2 $001C Undefined
Input capture low 2 $001D Undefined
Output compare high 2 $001E Undefined
Output compare low 2 $001F Undefined
Options (OPTR)(3) $0100 EE1P SEC Not affected
MC68HC05B6 MOTOROLA
E-1
MC68HC705B16
14
E
MC68HC705B16
The MC68HC705B16 is a device similar to the MC68HC05B6, but with increased RAM and
15 kbytes of EPROM instead of 6 kbytes of ROM. In addition, the self-check routines available in
the MC68HC05B6 are replaced by bootstrap firmware. The MC68HC705B16 is an OTPROM
(one-time programmable ROM) version of the MC68HC05B16, meaning that once the application
program has been loaded in the EPROM it can never be erased. The entire MC68HC05B6 data
sheet applies to the MC68HC705B16, with the exceptions outlined in this appendix.
Features
• 15 kbytes EPROM
• 352 bytes of RAM
• 576 bytes bootstrap ROM
• Simultaneous programming of up to 8 bytes of EPROM
• Optional pull-down resistors available on all port B and port C pins
• 52-pin PLCC and 64-pin QFP packages
Note:
The electrical characteristics of the MC68HC05B6 as provided in Section 11 do not
apply to the MC68HC705B16. Data specific to the MC68HC705B16 can be found in
this appendix.
To ensure correct operation of the MC68HC705B16 after power-on, the device must
be reset a second time after power-on. This can be done in software using the
MC68HC705B16 watchdog.
The following software sub-routine should be used:
RESET2 BSET 0, $0C Start watchdog
STOP STOP causes immediate watchdog
system reset
The interrupt vector at $3FF0 and $3FF1 must be initialised with the RESET2 address
value.
MOTOROLA
E-2 MC68HC705B16MC68HC705B16
14
Figure E-1 MC68HC705B16 block diagram
Port A
PA0
PA1
PA2
PA3
PA4
PA5
PA6
PA7
Port B
PB0
PB1
PB2
PB3
PB4
PB5
PB6
PB7
Port C
PC0
PC1
PC2/ECLK
PC3
PC4
PC5
PC6
PC7
16-bit
timer
Port D
PD0/AN0
PD1/AN1
PD2/AN2
PD3/AN3
PD4/AN4
PD5/AN5
PD6/AN6
PD7/AN7
Oscillator
COP watchdog
RESET
IRQ
VDD
VSS
OSC1
OSC2
M68HC05
CPU
SCI
A/D converter
PLM
TCAP1
TCAP2
TCMP1
TCMP2
VRH
VRL
RDI
SCLK
TDO
VPP1
256 bytes
EEPROM
Charge pump
2 / 32
PLMA D/A
PLMB D/A
8-bit
15168 bytes
EPROM
352 bytes
static RAM
576 bytes
VPP6
bootstrap ROM
MC68HC05B6 MOTOROLA
E-3
MC68HC705B16
14
Figure E-2 Memory map of the MC68HC705B16
MOTOROLA
E-4 MC68HC705B16MC68HC705B16
14
(1) This bit is set each time there is a power-on reset.
(2) The state of the WDOG bit after reset is dependent upon the mask option selected; 1=watchdog enabled, 0=watchdog disabled.
(3) This register is implemented in EEPROM; therefore reset has no effect on the individual bits.
(4) This register is implemented in EPROM; therefore reset has no effect on the individual bits.
Table E-1 Register outline
Register name Address bit 7 bit 6 bit 5 bit 4 bit 3 bit 2 bit 1 bit 0 State on
reset
Port A data (PORTA) $0000 Undefined
Port B data (PORTB) $0001 Undefined
Port C data (PORTC) $0002 PC2/
ECLK Undefined
Port D data (PORTD) $0003 PD7 PD6 PD5 PD4 PD3 PD2 PD1 PD0 Undefined
Port A data direction (DDRA) $0004 0000 0000
Port B data direction (DDRB) $0005 0000 0000
Port C data direction (DDRC) $0006 0000 0000
EPROM/EEPROM/ECLK control $0007
E6LAT E6PGM ECLK E1ERA E1LAT E1PGM 0000 0000
A/D data (ADDATA) $0008 0000 0000
A/D status/control (ADSTAT) $0009 COCO ADRC ADON 0 CH3 CH2 CH1 CH0 0000 0000
Pulse length modulation A (PLMA) $000A 0000 0000
Pulse length modulation B (PLMB) $000B 0000 0000
Miscellaneous $000C POR(1) INTP INTN INTE SFA SFB SM WDOG(2) ?001 000?
SCI baud rate (BAUD) $000D SPC1 SPC0 SCT1 SCT0 SCT0 SCR2 SCR1 SCR0 00uu uuuu
SCI control 1 (SCCR1) $000E R8 T8 M WAKE CPOL CPHA LBCL Undefined
SCI control 2 (SCCR2) $000F TIE TCIE RIE ILIE TE RE RWU SBK 0000 0000
SCI status (SCSR) $0010 TDRE TC RDRF IDLE OR NF FE 1100 000u
SCI data (SCDR) $0011 0000 0000
Timer control (TCR) $0012 ICIE OCIE TOIE FOLV2 FOLV1 OLV2 IEDG1 OLVL1 0000 00u0
Timer status (TSR) $0013 ICF1 OCF1 TOF ICF2 OCF2 Undefined
Input capture high 1 $0014 Undefined
Input capture low 1 $0015 Undefined
Output compare high 1 $0016 Undefined
Output compare low 1 $0017 Undefined
Timer counter high $0018 1111 1111
Timer counter low $0019 1111 1100
Alternate counter high $001A 1111 1111
Alternate counter low $001B 1111 1100
Input capture high 2 $001C Undefined
Input capture low 2 $001D Undefined
Output compare high 2 $001E Undefined
Output compare low 2 $001F Undefined
Options (OPTR)(3) $0100 EE1P SEC Not affected
Mask option register (MOR)(4) $3DFE RTIM RWAT WWAT PBPD PCPD Not affected
MC68HC05B6 MOTOROLA
E-5
MC68HC705B16
14
E.1 EPROM
The MC68HC705B16 memory map is given in Figure E-2. The device has a total of 15168 bytes
of EPROM (including 14 bytes for User vectors) and 256 bytes of EEPROM.
The EPROM array is supplied by the VPP6 pin in both read and program modes. Typically the
user’s software would be loaded into a programming board where VPP6 is controlled by one of the
bootstrap loader routines. It w ould then be placed in an application where no programming occurs.
In this case the VPP6 pin should be hardwired to VDD.
Warning: A minimum VDD voltage must be applied to the VPP6 pin at all times, including
power-on. Failure to do so could result in permanent damage to the device.
E.1.1 EPROM read operation
The execution of a program in the EPROM address range or a load from the EPROM are both
read operations. The E6LAT bit in the EPROM/EEPROM control register should be cleared to ‘0’
which automatically resets the E6PGM bit. In this way the EPROM is read like a nor mal ROM.
Reading the EPROM with the E6LAT bit set will give data that does not correspond to the actual
memory content. As interrupt vectors are in EPROM, they will not be loaded when E6LAT is set.
Similarly, the bootstrap ROM routines cannot be executed when E6LAT is set. In read mode, the
VPP6 pin must be at the VDD level. When entering the STOP mode, the EPROM is automatically
set to the read mode.
Note:
An erased byte reads as $00.
E.1.2 EPROM program operation
Typically the EPROM will be programmed by the bootstrap routines resident in the on-chip ROM.
However, the user program can be used to program some EPROM locations if the proper
procedure is followed. In particular, the programming sequence must be running in RAM, as the
EPROM will not be available for code execution while the E6LAT bit is set. The VPP6 switching
must occur externally after the E6PGM bit is set, for example under control of a signal generated
on a pin by the programming routine.
Note:
When the part becomes a PROM, only the cumulative programming of bits to logic ‘1’
is possible if multiple programming is made on the same byte.
To allow simultaneous programming of up to eight bytes, these bytes must be in the same group
of addresses which share the same most significant address bits; only the three least significant
bits can change.
MOTOROLA
E-6 MC68HC705B16MC68HC705B16
14
E.1.3 EPROM/EEPROM/ECLK control register
E6LAT — EPROM programming latch enable bit
1 (set) – Address and up to eight data bytes can be latched into the EPROM
for further programming providing the E6PGM bit is cleared.
0 (clear) – Data can be read from the EPROM or firmware ROM; the E6PGM bit
is reset to zero when E6LAT is ‘0’.
STOP, power-on and external reset clear the E6LAT bit.
Note:
After the tERA1 erase time or tPROG1 programming time, the E6LAT bit has to be reset
to zero in order to clear the E6PGM bit.
E6PGM — EPROM program enable bit
This bit is the EPROM program enable bit. It can be set to ‘1’ to enable programming only after
E6LAT is set and at least one byte is written to the EPROM. It is not possible to clear this bit using
software but clearing E6LAT will always clear E6PGM.
Note:
The E6PGM bit can never be set while the E6LAT bit is at zero.
ECLK
See Section 4.3.
Address bit 7 bit 6 bit 5 bit 4 bit 3 bit 2 bit 1 bit 0 State
on reset
EPROM/EEPROM/ECLK control $0007 E6LAT E6PGM ECLK E1ERA E1LAT E1PGM 0000 0000
Table E-2 EPROM control bits description
E6LAT E6PGM Description
0 0 Read/execute in EPROM
1 0 Ready to write address/data to EPROM
1 1 programming in progress
MC68HC05B6 MOTOROLA
E-7
MC68HC705B16
14
E1ERA — EEPROM erase/programming bit
Providing the E1LAT and E1PGM bits are at logic one, this bit indicates whether the access to the
EEPROM is for erasing or programming purposes.
1 (set) – An erase operation will take place.
0 (clear) – A programming operation will take place.
Once the program/erase EEPROM address has been selected, E1ERA cannot be changed.
E1LAT — EEPROM programming latch enable bit
1 (set) – Address and data can be latched into the EEPROM for further
program or erase operations, providing the E1PGM bit is cleared.
0 (clear) – Data can be read from the EEPROM. The E1ERA bit and the
E1PGM bit are reset to zero when E1LAT is ‘0’.
STOP, power-on and external reset clear the E1LAT bit.
Note:
After the tERA1 erase time or tPROG1 programming time, the E1LAT bit has to be reset
to zero in order to clear the E1ERA bit and the E1PGM bit.
E1PGM — EEPROM charge pump enable/disable
1 (set) – Internal charge pump generator switched on.
0 (clear) – Internal charge pump generator switched off.
When the charge pump generator is on, the resulting high voltage is applied to the EEPROM array.
This bit cannot be set before the data is selected, and once this bit has been set it can only be
cleared by clearing the E1LAT bit.
A summary of the effects of setting/clearing bits 0, 1 and 2 of the control register are given in Table E-3.
Note:
The E1PGM and E1ERA bits are cleared when the E1LAT bit is at zero.
Table E-3 EEPROM control bits description
E1ERA E1LAT E1PGM Description
0 0 0 Read condition
0 1 0 Ready to load address/data for program/erase
0 1 1 Byte programming in progress
1 1 0 Ready for byte erase (load address)
1 1 1 Byte erase in progress
MOTOROLA
E-8 MC68HC705B16MC68HC705B16
14
E.1.4 Mask option register
RTIM — Reset time
This bit can modify the time tPORL, where the RESET pin is kept low after a power-on reset.
1 (set) – tPORL = 16 cycles.
0 (clear) – tPORL = 4064 cycles.
RWAT — Watchdog after reset
This bit can modify the status of the watchdog counter after reset. Usually, the watchdog system
is disabled after power-on or external reset but when this bit is set, it will be active immediately
after the following resets (except in bootstrap mode).
WWAT — Watchdog during WAIT mode
This bit can modify the status of the watchdog counter in WAIT mode. Normally, the watchdog
system is disabled in WAIT mode but when this bit is set, the watchdog will be active in WAIT
mode.
PBPD — Port B pull-down
This bit, when programmed, connects a resistive pull-down on each pin of port B. This pull-down,
RPD, is active on a given pin only while it is an input.
PCPD — Port C pull-down
This bit, when programmed, connects a resistiv e pull-down on each pin of port C. This pull-down,
RPD, is active on a given pin only while it is an input.
(1) This register is implemented in EPROM; therefore reset has no effect on the individual bits.
Address bit 7 bit 6 bit 5 bit 4 bit 3 bit 2 bit 1 bit 0 State
on reset
Mask option register (MOR)(1) $3DFE
RTIM RWAT WWAT PBPD PCPD Not affected
MC68HC05B6 MOTOROLA
E-9
MC68HC705B16
14
E.1.5 EEPROM options register (OPTR)
EE1P – EEPROM protect bit
In order to achieve a higher degree of protection, the EEPROM is effectively split into two parts,
both working from the VPP1 charge pump. Part 1 of the EEPROM array (32 bytes from $0100 to
$011F) cannot be protected; part 2 (224 bytes from $0120 to $01FF) is protected by the EE1P bit
in the options register.
1 (set) – Part 2 of the EEPROM array is not protected; all 256 bytes of
EEPROM can be accessed for any read, erase or programming
operations.
0 (clear) – Part 2 of the EEPROM array is protected; any attempt to erase or
program a location will be unsuccessful.
When this bit is set to 1 (erased), the protection will remain until the next power-on or external
reset. EE1P can only be written to ‘0’ when the E1LAT bit in the EEPROM control register is set.
Note:
The EEPROM1 protect function is disabled while in bootstrap mode.
SEC — Secure bit
This bit allows the EPROM and EEPROM1 to be secured from external access. When this bit is
in the erased state (set), the EPROM and EEPROM1 content is not secured and the device may
be used in non user mode. When the SEC bit is programmed to ‘zero’, the EPROM and
EEPROM1 content is secured b y prohibiting entry to the non user mode. To deactivate the secure
bit, the EPROM has to be er ased by exposure to a high density ultraviolet light, and the de vice has
to be entered into the EPROM erase verification mode with PD1 set. When the SEC bit is
changed, its new value will have no effect until the next power-on or external reset.
1 (set) – EEPROM/EPROM not protected.
0 (clear) – EEPROM/EPROM protected.
(1) This register is implemented in EEPROM; therefore reset has no effect on the individual bits.
Address bit 7 bit 6 bit 5 bit 4 bit 3 bit 2 bit 1 bit 0 State
on reset
Options (OPTR)(1) $0100
EE1P SEC Not affected
MOTOROLA
E-10 MC68HC705B16MC68HC705B16
14
E.2 Bootstrap mode
The 432 bytes of self-chec k firmware on the MC68HC05B6 are replaced by 576 b ytes of bootstrap
firmware. A detailed description of the modes of operation within bootstrap mode is given below.
The bootstrap program in mask R OM address locations $0200 to $024F and $3E00 to $3FEF can
be used to program the EPROM and the EEPROM, to check if the EPROM is erased or to load
and execute data in RAM.
After reset, while going to the bootstrap mode, the vector located at address $3FEE and $3FEF
(RESET) is fetched to start execution of the bootstrap program. To place the part in bootstrap
mode, theIRQ pin should be at + 9V with the TCAP1 pin ‘high’ during transition of the RESET pin
from low to high. The hold time on the IRQ and TCAP1 pins is two clock cycles after the external
RESET pin is brought high.
When the MC68HC705B16 is placed in the bootstrap mode, the bootstrap reset vector is fetched
and the bootstrap firmware starts to execute. Table E-4 shows the conditions required to enter
each level of bootstrap mode on the rising edge of RESET.
The bootstrap program first copies part of itself in RAM (except ‘RAM parallel load’), as the
program cannot be executed in ROM during verification/programming of the EPROM. It then sets
the TCMP1 output to a logic high level.
Table E-4 Mode of operation selection
IRQ pin TCAP1 pin PD1 PD2 PD3 PD4 Mode
VSS to VDD VSS to VDD x x x x Single chip
+ 9 Volts VDD 0 0 x 0 Erased EPROM verification (EEV)
+ 9 Volts VDD 1 0 0 0 Erased EPROM verification; erase EEPROM; EPROM/EEPROM
parallel program/verify
+ 9 Volts VDD 1 0 1 0 Erased EPROM verification; erase EEPROM;
EPROM/EEPROM/ RAM serial bootstrap load and execute
+ 9 Volts VDD x x 0 1 RAM parallel bootstrap load and execute (if SEC bit = 1)
+ 9 Volts VDD x x 1 1 Serial EPROM/EEPROM/RAM bootloader (if SEC = 1)
x = Don’t care
MC68HC05B6 MOTOROLA
E-11
MC68HC705B16
14
Figure E-3 Modes of operation flow chart (1 of 2)
PD3 set?
EEPR OM1 er ased?
TCAP1 set?
IRQ at 9V?
PD2 set?PD4 set?
Reset
Program EPROM;
parallel load; green LED
flashes
User mode
Green LED on
Red LED on
Non-user mode
Red LED on Green LED on
Non-user mode
A
N
YY
Y
Y N
Y N
N
NY
N
Y
Bootstrap mode
EPROM not erased
EPROM verified
Parallel E/EEPROM bootstrap
Bad EPROM programming
N
PD1 set?
Bulk erase EEPROM1
Red LED on
Red LED off
N
Y
Y
N
B
N
Y
Erased EPROM verification
SEC bit active?
EPROM
erased?
Programming OK?
MOTOROLA
E-12 MC68HC705B16MC68HC705B16
14
Figure E-4 Modes of operation flow chart (2 of 2)
Negative
address?
PD4 set?
PD3 set?
Transmit last four
programmed locations
A
Receive address
Receive four data
Execute RAM
program at $008B
Green LED on
Load next RAM
byte
RAM1 full?
Execute RAM
program at $0050
Program E/EEPROM
data at address; green
LED flashes
N
Y
Y
Y
Y
N
N
Serial E/EEPROM (RAM) bootstrap
Parallel bootstrap RAM
SEC bit set?
Red LED flashes
B
N
Y
N
MC68HC05B6 MOTOROLA
E-13
MC68HC705B16
14
E.2.1 Erased EPROM verification
If a non $00 byte is detected, the red LED is turned on and the routine stops (see Figure E-3 and
Figure E-4). Only when the entire EPROM content is v erified as erased does the green LED s witch
on. PD1 is then checked. If PD1=0, the bootstrap program stops here and no prog ramming occurs
until such time as a high level is sensed on PD1. If PD1=1, the bootstrap program proceeds to
erase the EEPROM1 for a nominal 100 ms (4.0 MHz crystal). It is then checked for complete
erasure; if a non $FF b yte is detected, the red LED is turned on, and erase is performed a second
time, and so on until total erasure is verified. At this point, both EPROM and EEPROM1 are
completely erased and the security bit is cleared. The programming operation can then be
performed. A schematic diagram of the circuit required f or erased EPROM verification is shown in
Figure E-7.
E.2.2 EPROM/EEPROM parallel bootstrap
Before the parallel bootstrap routines begin, the erased EPROM verification program is executed
as described in Section E.2.1. When PD2=0, the programming time is set to 5 milliseconds with
the bootstrap program and verify for the EPROM taking approximately 15 seconds. The EPROM
is loaded in increasing address order with non EPROM segments being skipped by the loader.
Simultaneous programming is performed by reading eight bytes of data before actual
programming is performed, thus the loading time of the internal EPROM is divided by eight.
Parallel data is entered through Port A, while the 14-bit address is output on port B, PC0 to PC4
and TCMP2. If the data comes from an external EPROM, the handshake can be disabled by
connecting together PC5 and PC6. If the data is supplied by a parallel interface, handshaking will
be provided by PC5 and PC6 according to the timing diagram of Figure E-5 (see also Figure E-6).
Figure E-5 Timing diagram with handshake
Data read Data read
Address
HDSK out
(PC5)
Data
HDSK in
(PC6)
F29
MOTOROLA
E-14 MC68HC705B16MC68HC705B16
14
During programming, the green LED will flash at about 3 Hz.
Upon completion of the programming operation, the contents of the EPROM and EEPROM1 are
checked against the external data source. If programming is v erified the green LED sta ys on, while
an error will cause the red LED to be turned on. Figure E-7 is a schematic diagram of a circuit that
can be used to program the EPROM or to load and execute data in the RAM.
Note:
The entire EPROM and EEPROM1 can be loaded from the external source; if it is
desired to leave a segment undisturbed, the data for this segment should be all zeros
for EPROM data and all $FFs for EEPROM1 data.
Figure E-6 Parallel EPROM loader timing diagram
tCOOE
tADE tDHE
Address
Data
tADE tDHE
tADE tDHE
tADE tDHE
tCOOE tCOOE tCDDE
tADE max (address to data delay) 5 machine cycles
tDHA min (data hold time) 14 machine cycles
tCOOE (load cycle time) 117 machine cycles < tCOOE < 150 machine cycles
tCDDE (programming cycle time) tCOOE + tPROG (5ms nominal for EPROM; 10ms for EEPROM1))
1 machine cycle = 1/(2f0(Xtal))
MC68HC05B6 MOTOROLA
E-15
MC68HC705B16
14
Figure E-7 EPROM Parallel bootstrap schematic diagram
VCC
281
VPP PGM
27
PB0
PB1
PB2
PB3
PB4
PB5
PB6
PB7
PA0
PA1
PA2
PA3
PA4
PA5
PA6
PA7
VDD
OSC1
OSC2
TCAP1
IRQ
RESET
VSS
A0
A1
A2
A3
A4
A5
A6
A7
D0
D1
D2
D3
D4
D5
D6
D7
GND OE
14 22
10
9
8
7
6
5
4
26
12
13
15
16
17
18
19
11
3
+5V
1
2
P1 GND
+5V
100F
22pF
4.0 MHz
1N914
1k
1.0F
22pF
100k
1N914
RESET RUN
0.01F
TDO
SCLK
RDI
VRL
TCAP2
PD7
PD6
PD5
PD3
PD2
PD1
PD0
PD4
+5V
3VPP
VPP6
PC7
PC5
PC4
PC3
PC2
PC1
PC0
PC6
24
21
23
2
A9
A8
A10
A12
CE
A11
A12
A11
A10
A9
A8
HDSK out
HDSK in
Short circuit if
handshake not used
100 k
NC
TCMP1
TCMP2
PLMA
PLMB
470
470
red LED
green LED
4k7
4k7
12 k
BC239C
BC309C
10k 
27C128
+
+
VRH
red LED — programming failed
green LED — programming OK
25
1nF
1N5819
1 k
+
RAM
EPROM
green LED — EPROM erased
47F +
Erase check & boot
EPROM erase
check
VPP1
red LED — EPROM not erased
Boot
Erase check
A13
20
MC68HC705B16
MCU
MOTOROLA
E-16 MC68HC705B16MC68HC705B16
14
E.2.3 EEPROM/EPROM/RAM serial bootstrap
For erased EPROM verification, PD4 must be at ‘0’. In this case, erased EPROM verification
executes as described in Section E.2.1 before control is given to the serial routine.
If PD4 is at ‘1’, the program initially checks the state of the security bit. If the security bit is active
(‘0’), the program will not enter serial bootstrap and the red LED will flash. Otherwise the serial
bootstrap program will be executed according to Figure E-3 and Figure E-4.
The serial routine communicates through the SCI with an external host, typically a PC, by means
of an RS232 link at 9600 baud, 8-bit, no parity and full duplex. Refer to Figure E-8 for a schematic
diagram of a suitable circuit.
Note:
Data format is not ASCII, but 8-bit binary, so a complementary program must be run by
the host to supply the required f ormat. Such a program is a vailable for the IBM PC from
Motorola.
The EPROM bootstrap routines are used to customise the OTP EPROM. To increase the speed
of programming the 15 kbytes, four bytes are programmed while the data is simultaneously
transmitted back and forward in full duplex. This implies that while 4 b ytes are being programmed
the next 4 bytes are received and the preceding 4 bytes are echoed. The format accepted by the
serial loader is as follows:
1 EPROM locations
[address n high] [address n low] [data(n)] [data (n+1)] [data (n+2)] [data (n+3)]
Address n must have the two least significant bits at zero so that n, n+1, n+2 and n+3
have identical most significant bits. These blocks of four bytes do not need to be
contiguous, as a new address is transmitted for each new group.
2 EEPROM1 locations
[address n high] [address n low] [data(n)] [dummy data 1] [dummy data 2] [dummy data 3]
The same four byte protocol of data exchange is used, but only the first data value is
programmed at address n. The three f ollowing dummy data v alues must be sent to be
in agreement with the protocol, but are not significant.
The protocol is as follows:
1 The MC68HC705B16 sends the last two bytes programmed to the host as
a prompt; this also allows the host to verify that programming has been
carried out correctly.
2 In response to the first byte prompt, the host sends the first address byte.
3 After receiving the first address byte, the MC68HC705B16 sends the next
byte programmed.
MC68HC05B6 MOTOROLA
E-17
MC68HC705B16
14
Figure E-8 RAM/EPROM/EEPROM serial bootstrap schematic diagram
Green LED — programming ended
Flashing green LED — programming
40
VPP6
PC7
PB0
PB1
PB2
PB3
PB4
PB5
PB6
PB7
PA0
PA1
PA2
PA3
PA4
PA5
PA6
PA7
VDD
OSC1
OSC2
TCAP1
IRQ
RESET
VSS
1
2
P1 GND
+5V
1N914
1k
1.0F
100k
1N914
RESET RUN
0.01F
3VPP
PC5
PC4
PC3
PC2
PC1
PC0
PC6
PLMA
PLMB
470
470
Red LED
Green LED
+
+
VRH
22F
22F
22F
2 x 3K 1
23
4
8
6
7
5
11
1213
14
15
16
53
2
1
22F
RS232
connector MAX
232
+5V
9600 BD
8-bit
no parity
19
18
20
21
50
52
39
38
37
36
35
34
33
32
31
30
29
28
27
26
25
24
14
13
12
5
4
43
44
45
46
47
48
49
23
2
1
51
22 8 10
41 7
VRL
TCAP2
TCMP1
TCMP2
SCLK
NC
10nF 47F
PD0
PD4
PD1
PD2
PD5
PD6
PD7
+
+
+
+
22pF 4.0 MHz
22pF
4k7
4k7
12 k
BC239C
BC309C
10k 
1nF
1N5819
1 k
+
Serial boot
Erase check
47F +
PD3
RDI
TDO
Erase check
Red LED — EPROM not erased
Green LED — EPROM erased
Serial boot &
serial boot
Erase check and serial boot
EPROM erase check
VPP1
3
U2 MC68HC705B16
MCU (socket)
MOTOROLA
E-18 MC68HC705B16MC68HC705B16
14
4The exchange of data continues until the MC68HC705B16 has sent the four
data bytes and the host has sent the 2 address data bytes and 4 data b ytes.
5 If the data is different from $00 for EPROM or $FF for EEPROM, it is
programmed at the address pro vided, while the ne xt address and bytes are
received and the previous data is echoed.
6 Loop to 1.
After reset, the MC68HC705B16 serial bootstrap routine will first echo two blocks of four bytes at
$00, as no data is programmed yet.
If the data received is $00 for EPROM locations or $FF for EEPROM locations, no programming
in the EPROM and EEPR OM1 takes place, and the contents of the accessed location are returned
as a prompt. The entire EPROM/EEPROM memory can be read in this fashion (serial dump).
Warning: When using this function with a programmed device, the device must be placed into
RAM/EPROM/EEPR OM serial bootstrap mode without EPR OM erase chec k (PD4 = 1).
Serial RAM loading and execute can be accomplished in this mode. A RAM byte will be written if
the address sent by the host in the serial protocol points to the RAM.
RAM bytes $008B–$00E3 and $0250–$02ED are a vailable f or user test programs. A 10-byte stack
resides at the top of RAMI, allowing, for example, one interrupt and two sub-routine levels. The
RAM addresses between $0050 and $008A are used b y the loader and are therefore not a vailable
to the user during serial loading/executing.
If the SEC bit is at ‘1’, program execution is triggered by sending a negative (bit 7 set) high
address; execution starts at address XADR ($008B).
In the RAM bootloader mode, all interrupt vectors are mapped to pseudo-vectors in RAM (see
Table E-5). This allows programmers to use their own service-routine addresses. Each
pseudo-vector is allowed three bytes of space rather than the two bytes for normal vectors,
because an explicit jump (JMP) opcode is needed to cause the desired jump to the user’ s service
routine address.
Table E-5 Bootstrap vector targets in RAM
Vector targets in RAM
SCI interrupt $02EE
Timer overflow $02F1
Timer output compare $02F4
Timer input capture $02F7
IRQ $02FA
SWI $02FD
MC68HC05B6 MOTOROLA
E-19
MC68HC705B16
14
E.2.4 RAM parallel bootstrap
The program first checks the state of the security bit. If the SEC bit is active, i.e. ‘0’, the program
will not enter the RAM bootstrap mode and the red LED will flash. Otherwise the RAM bootstrap
program will start loading the RAM with external data (e.g. from a 2564 or 2764 EPROM). Before
loading a new byte the state of the PD4/AN4 pin is checked. If this pin goes to level ‘0’, or if the
RAM is full, then control is given to the loaded program at address $0050. See Figure E-3 and
Figure E-4.
If the data is supplied by a parallel interface, handshaking will be provided by PC5 and PC6
according to Figure E-9. If the data comes from an external EPROM, the handshake can be
disabled by connecting together PC5 and PC6.
Figure E-10 provides a schematic diagram of a circuit that can be used to load the RAM with short
test programs. Up to 8 programs can be loaded in turn from the EPROM. Selection is
accomplished by means of the switches connected to the EPROM higher address lines (A8
through A10). If the user program sets PC0 to level ‘1’, this will disab le the external EPROM, thus
rendering both port A output and port B input available. The EPROM parallel bootstrap loader
schematic can also be used (Figure E-7), provided VPP is at VDD level. The high order address
lines will be at zero. The LEDs will stay off.
Figure E-9 Parallel RAM loader timing diagram
tADR tDHR
Address
Data
tCR
PD4 tEXR max
tHO
tHI max
PC5 out
PC6 in
tADR max (address to data delay; PC6=PC5) 16 machine cycles
tDHR min (data hold time) 4 machine cycles
tCR (load cycle time; PC6=PC5) 49 machine cycles
tHO (PC5 handshake out delay) 5 machine cycles
tHI max (PC6 handshake in, data hold time) 10 machine cycles
tEXR max (max delay for transition to be recognised during this cycle; PC6=PC5 30 machine cycles
1 machine cycle = 1/(2f0(Xtal))
MOTOROLA
E-20 MC68HC705B16MC68HC705B16
14
E.2.4.1 Jump to start of RAM ($0050)
PD4 must be high during the first 49 program cycles and pulled low before the 68th cycle for
immediate jump execution at address $0050.
Note:
Figure E-10 RAM parallel bootstrap schematic diagram
PB0
PB1
PB2
PB3
PB4
PB5
PB6
PB6
PB7
PA0
PA1
PA2
PA3
PA4
PA5
PA6
PA7
VDD
TCAP2
TCMP2
TCMP1
PLMB
PLMA
SCLK
TDO
RDI
VRH
VRL
PD7
PD6
PD5
PD3
PD2
PD1
PD0
PC7
PC6
PC5
PC4
PC3
PC2
PC1
PC0
NC
OSC1
OSC2
TCAP1
IRQ
RESET
PD4
VPP6
VSS
A0
A1
A2
A3
A4
A5
A6
A7
D0
D1
D2
D3
D4
D5
D6
D7
GND OE
A8
A9
A10
A11
A12
CE
VCCPGMVPP
20
2
25
24
23
14 22
10
9
8
7
6
5
4
1 26 27 28
21
12
13
15
16
17
18
19
11
3
+5V
3 x 4.7k
+5V
16 x 100k
1
2
P1 GND
+5V
100F
22pF 4.0 MHz
1N914
1k
1.0F
22pF
100k
1N914
RESET RUN
0.01F
U1
2764
+5V 18 x 100 k
+
+
NC
VPP1
U2 MC68HC705B16
MCU (socket)
MC68HC05B6 MOTOROLA
E-21
MC68HC705B16
14
E.2.5 Maximum ratings
Note:
This device contains circuitry designed to protect against damage due to high
electrostatic voltages or electric fields. However, it is recommended that normal
precautions be taken to avoid the application of any voltages higher than those given
in the maximum ratings table to this high impedance circuit. For maximum reliability all
unused inputs should be tied to either VSS or VDD.
(1) All voltages are with respect to VSS.
(2) Maximum current drain per pin is for one pin at a time, limited by an external resistor.
Table E-6 Maximum ratings
Rating Symbol Value Unit
Supply voltage(1) VDD – 0.5 to +7.0 V
Input voltage VIN VSS – 0.5 to VDD + 0.5 V
Input voltage
– Self-check mode (
IRQ pin only) VIN VSS – 0.5 to 2VDD + 0.5 V
Operating temperature range
– Standard (MC68HC705B16)
– Extended (MC68HC705B16C)
– Industrial (MC68HC705B16V)
– Automotive (MC68HC705B16M)
TATL to TH
0 to +70
–40 to +85
–40 to +105
–40 to +125
C
Storage temperature range TSTG – 65 to +150 C
Current drain per pin (e xcluding VDD and VSS) (2)
– Source
– Sink ID
IS
25
45 mA
mA
MOTOROLA
E-22 MC68HC705B16MC68HC705B16
14
E.2.6 Thermal characteristics and power considerations
The average chip junction temperature, TJ, in degrees Celsius can be obtained from the following
equation:
[1]
where:
TA = Ambient temperature (C)
θJA = Package thermal resistance, junction-to-ambient (C/W)
PD = PINT + PI/O (W)
PINT = Internal chip power = IDD • VDD (W)
PI/O = Power dissipation on input and output pins (user determined)
An approximate relationship between PD and TJ (if PI/O is neglected) is:
[2]
Solving equations [1] and [2] for K gives:
[3]
where K is a constant f or a particular part. K can be determined by measuring PD (at equilibrium)
for a known TA. Using this value of K, the values of PD and TJ can be obtained for any value of TA
by solving the above equations. The package thermal characteristics are shown in Table E-7.
Table E-7 Package thermal characteristics
Characteristics Symbol Value Unit
Thermal resistance
– 64-pin quad flat package
θ
JA 50 C/W
– Plastic 56 pin shrink DIL package Not available for this device
– Plastic 52 pin PLCC package
θ
JA 50 C/W
Figure E-11 Equivalent test load
TJTAPD
θJA
•( )+=
PDK
TJ
273+
---------------------
=
K PDTA273+( )• θJA PD
2
•+=
VDD = 4.5/3.0 V
R2
R1C
Test
point
Voltage Pins R1 R2 C
4.5V PA0–7, PB0–7, PC0–7 3.26k 2.38k 50pF
3.0V PA0–7, PB0–7, PC0–7 10.91k 6.32k 50pF
MC68HC05B6 MOTOROLA
E-23
MC68HC705B16
14
E.2.7 DC electrical characteristics
Table E-8 DC electrical characteristics for 5V operation
(VDD = 5 Vdc  10%, VSS = 0 Vdc, TA = TL to TH)
Characteristic(1) Symbol Min Typ(2) Max Unit
Output voltage
ILOAD = – 10 A
ILOAD = +10 A VOH
VOL VDD – 0.1
——
——
0.1 V
Output high voltage (ILOAD = 0.8mA)
PA0–7, PB0–7, PC0–7, TCMP1, TCMP2
Output high voltage (ILOAD = 1.6mA)
TDO, SCLK, PLMA, PLMB
VOH
VOH
VDD – 0.8
VDD – 0.8
VDD – 0.4
VDD – 0.4
—
—V
Output low voltage (ILOAD = 1.6mA)
PA0–7, PB0–7, PC0–7, TCMP1, TCMP2,
TDO, SCLK, PLMA, PLMB
Output low voltage (ILOAD = 1.6mA)
RESET
VOL
VOL
— 0.1
0.4
0.4
1V
Input high voltage
PA0–7, PB0–7, PC0–7, PD0–7, OSC1,
IRQ, RESET, TCAP1, TCAP2, RDI VIH 0.7VDD — VDD V
Input low voltage
PA0–7, PB0–7, PC0–7, PD0–7, OSC1,
IRQ, RESET, TCAP1, TCAP2, RDI VIL VSS — 0.2VDD V
Supply current(3)
RUN (SM = 0) (See Figure 11-2)
RUN (SM = 1) (See Figure 11-3)
WAIT (SM = 0) (See Figure 11-4)
WAIT (SM = 1) (See Figure 11-5)
STOP 0 to 70 (standard)
– 40 to 85 (extended)
– 40 to 105 (industrial)
– 40 to 125 (automotive)
IDD
IDD
IDD
IDD
IDD
IDD
IDD
IDD
—
—
—
—
—
—
—
—
5.0
1.0
1.5
0.9
2
—
—
—
6
1.5
2
1
10
20
60
60
mA
mA
mA
mA
A
A
A
A
EPROM
Absolute maximum voltage
Programming voltage
Programming current
Read voltage
VPP6 max
VPP6
IPP6
VPP6R
VDD
15
—
VDD
—
15.5
50
VDD
18
16
64
VDD10%
V
V
mA
V
High-Z leakage current
PA0–7, PB0–7, PC0–7, TDO, RESET, SCLK IIL — 0.2 1 A
Input current
Port B and port C pull-down (VIN=VIH) IRPD 80 A
Input current (0 to 70)
IRQ, OSC1, TCAP1, TCAP2, RDI,
PD0/AN0-PD7/AN7 (channel not selected) IIN — 0.2 1 A
Input current (– 40 to 125)
IRQ, OSC1, TCAP1, TCAP2, RDI,
PD0/AN0-PD7/AN7 (channel not selected) IIN — — 5 A
Capacitance
Ports (as input or output),RESET, TDO, SCLK
IRQ, TCAP1, TCAP2, OSC1, RDI
PD0/AN0–PD7/AN7 (A/D off)
PD0/AN0–PD7/AN7 (A/D on)
COUT
CIN
CIN
CIN
—
—
—
—
—
—
12
22
12
8
—
—
pF
pF
pF
pF
MOTOROLA
E-24 MC68HC705B16MC68HC705B16
14
(1) All IDD measurements taken with suitable decoupling capacitors across the power supply to suppress the
transient switching currents inherent in CMOS designs (see Section 2).
(2) Typical values are at mid point of voltage range and at 25C only.
(3) RUN and WAIT IDD: measured using an external square-wave clock source (fOSC =4.2MHz); all inputs 0.2 V
from rail; no DC loads; maximum load on outputs 50pF (20pF on OSC2).
STOP /WAIT IDD: all ports configured as inputs; VIL = 0.2 V and VIH = VDD – 0.2 V: STOP IDD measured with
OSC1 = VDD.
WAIT IDD is affected linearly by the OSC2 capacitance.
MC68HC05B6 MOTOROLA
E-25
MC68HC705B16
14
(1) All IDD measurements taken with suitable decoupling capacitors across the po wer supply to suppress the tr ansient switching
currents inherent in CMOS designs (see Section 2).
(2) Typical values are at mid point of voltage range and at 25C only.
(3) RUN and WAIT IDD: measured using an external square-wave clock source (fOSC = 2.0MHz); all inputs 0.2 V from rail; no
DC loads; maximum load on outputs 50pF (20pF on OSC2).
STOP /WAIT IDD: all ports configured as inputs; VIL = 0.2 V and VIH = VDD – 0.2 V: STOP IDD measured with OSC1 = VDD.
WAIT IDD is affected linearly by the OSC2 capacitance.
Table E-9 DC electrical characteristics for 3.3V operation
(VDD = 3.3Vdc  10%, VSS = 0Vdc, TA = TL to TH)
Characteristic(1) Symbol Min Typ(2) Max Unit
Output voltage
ILOAD = – 10 A
ILOAD = +10 A VOH
VOL
VDD – 0.1
——
——
0.1 V
Output high voltage (ILOAD = 0.8mA)
PA0–7, PB0–7, PC0–7, TCMP1, TCMP2
Output high voltage (ILOAD = 1.6mA)
TDO, SCLK, PLMA, PLMB
VOH
VOH
VDD – 0.3
VDD – 0.3
VDD – 0.1
VDD – 0.1
—
—
V
Output low voltage (ILOAD = 1.6mA)
PA0–7, PB0–7, PC0–7, TCMP1, TCMP2,
TDO, SCLK, PLMA, PLMB
Output low voltage (ILOAD = 1.6mA)
RESET
VOL
VOL
— 0.1
0.2
0.4
0.6
V
Input high voltage
PA0–7, PB0–7, PC0–7, PD0–7, OSC1,
IRQ, RESET, TCAP1, TCAP2, RDI VIH 0.7VDD — VDD V
Input low voltage
PA0–7, PB0–7, PC0–7, OSC1, IRQ,RESET,
TCAP1, TCAP2, RDI VIL VSS — 0.2VDD V
Supply current(3)
RUN (SM = 0) (See Figure 11-2)
RUN (SM = 1) (See Figure 11-3)
WAIT (SM = 0) (See Figure 11-4)
WAIT (SM = 1) (See Figure 11-5)
STOP 0 to 70 (standard)
– 40 to 85 (extended)
– 40 to 105 (industrial)
– 40 to 125 (automotive)
IDD
IDD
IDD
IDD
IDD
IDD
IDD
IDD
—
—
—
—
—
—
—
—
2.0
0.8
1.0
0.4
1
—
—
—
3
1
1.5
0.5
10
10
40
40
mA
mA
mA
mA
A
A
A
A
High-Z leakage current
PA0–7, PB0–7, PC0–7, TDO, RESET, SCLK IIL — 0.2 1 A
Input current
Port B and port C pull-down (VIN=VIH) IRPD 80 A
Input current (0 to 70)
IRQ, OSC1, TCAP1, TCAP2, RDI,
PD0/AN0-PD7/AN7 (channel not selected) IIN — 0.2 1 A
Input current (– 40 to 125)
IRQ, OSC1, TCAP1, TCAP2, RDI,
PD0/AN0-PD7/AN7 (channel not selected) IIN — — 5 A
Capacitance
Ports (as input or output),RESET, TDO, SCLK
IRQ, TCAP1, TCAP2, OSC1, RDI
PD0/AN0–PD7/AN7 (A/D off)
PD0/AN0–PD7/AN7 (A/D on)
COUT
CIN
CIN
CIN
—
—
—
—
—
—
12
22
12
8
—
—
pF
pF
pF
pF
MOTOROLA
E-26 MC68HC705B16MC68HC705B16
14
E.2.8 A/D converter characteristics
E.3 Control timing
(1) Performance verified down to 2.5V VR, but accuracy is tested and guaranteed at VR = 5V10%.
(2) Source impedances greater than 10k will adversely affect internal charging time during input sampling.
(3) The external system error caused by input leakage current is approximately equal to the product of R source and input
current. Input current to A/D channel will be dependent on external source impedance (see Figure 8-2).
Table E-10 A/D characteristics for 5V operation
(VDD = 5.0 Vdc  10%, VSS = 0 Vdc, TA = TL to TH)
Characteristic Parameter Min Max Unit
Resolution Number of bits resolved by the A/D 8 — Bit
Non-linearity Max deviation from the best straight line through the A/D
transfer characteristics
(VRH = VDD and VRL = 0V) —  0.5 LSB
Quantization error Uncertainty due to converter resolution —  0.5 LSB
Absolute accuracy Difference between the actual input voltage and the
full-scale equivalent of the binary code output code for all
errors —  1 LSB
Conversion range Analog input voltage range VRL VRH V
VRH Maximum analog reference voltage VRL VDD + 0.1 V
VRL Minimum analog reference voltage VSS – 0.1 VRH V
VR(1) Minimum difference between VRH and VRL 3 — V
Conversion time Total time to perform a single analog to digital conversion
a. External clock (OSC1, OSC2)
b. Internal RC oscillator —
—32
32 tCYC
s
Monotonicity Conversion result never decreases with an increase in
input voltage and has no missing codes GUARANTEED
Zero input reading Conversion result when VIN = VRL 00 — Hex
Full scale reading Conversion result when VIN = VRH — FF Hex
Sample acquisition time Analog input acquisition sampling
a. External clock (OSC1, OSC2)
b. Internal RC oscillator(2) —
—12
12 tCYC
s
Sample/hold capacitance Input capacitance on PD0/AN0–PD7/AN7 — 12 pF
Input leakage(3) Input leakage on A/D pins PD0/AN0–PD7/AN7, VRL, VRH — 1 A
MC68HC05B6 MOTOROLA
E-27
MC68HC705B16
14
(1) Source impedances greater than 10k will adversely affect internal charging time during input sampling.
(2) The external system error caused by input leakage current is approximately equal to the product of R source and input
current. Input current to A/D channel will be dependent on external source impedance (see Figure 8-2).
Table E-11 A/D characteristics for 3.3V operation
(VDD = 3.3 Vdc  10%, VSS = 0 Vdc, TA = TL to TH)
Characteristic Parameter Min Max Unit
Resolution Number of bits resolved by the A/D 8 — Bit
Non-linearity Max deviation from the best straight line through the A/D
transfer characteristics
(VRH = VDD and VRL = 0V) —  1 LSB
Quantization error Uncertainty due to converter resolution —  1 LSB
Absolute accuracy Difference between the actual input voltage and the
full-scale equivalent of the binary code output code for all
errors —  2 LSB
Conversion range Analog input voltage range VRL VRH V
VRH Maximum analog reference voltage VRL VDD + 0.1 V
VRL Minimum analog reference voltage VSS – 0.1 VRH V
VRMinimum difference between VRH and VRL 3 — V
Conversion time Total time to perform a single analog to digital conversion
Internal RC oscillator — 32 s
Monotonicity Conversion result never decreases with an increase in
input voltage and has no missing codes GUARANTEED
Zero input reading Conversion result when VIN = VRL 00 — Hex
Full scale reading Conversion result when VIN = VRH — FF Hex
Sample acquisition time Analog input acquisition sampling
Internal RC oscillator(1) — 12 s
Sample/hold capacitance Input capacitance on PD0/AN0–PD7/AN7 — 12 pF
Input leakage(2) Input leakage on A/D pins PD0/AN0–PD7/AN7, VRL, VRH — 1 A
MOTOROLA
E-28 MC68HC705B16MC68HC705B16
14
(1) For bus frequencies less than 2 MHz, the internal RC oscillator should be used when
programming the EEPROM.
(2) Since a 2-bit prescaler in the timer must count four external cycles (tcyc), this is the limiting
factor in determining the timer resolution.
(3) The minimum period tTLTL should not be less than the number of cycle times it takes to
execute the capture interrupt service routine plus 24 tcyc.
(4) The minimum period tILIL should not be less than the number of cycle times it takes to
execute the interrupt service routine plus 21 tcyc.
Table E-12 Control timing for 5V operation
(VDD = 5.0 Vdc  10%, VSS = 0 Vdc, TA = TL to TH)
Characteristic Symbol Min Max Unit
Frequency of operation
Crystal option
External clock option fOSC
fOSC
—
dc 4.2
4.2 MHz
MHz
Internal operating frequency (fOSC/2)
Crystal
External clock fOP
fOP
dc
dc 2.1
2.1 MHz
MHz
Cycle time (see Figure 9-1) tCYC 480 — ns
Crystal oscillator start-up time (see Figure 9-1) tOXOV — 100 ms
Stop recovery start-up time (crystal oscillator) tILCH 100 ms
RC oscillator stabilization time tADRC 100 ms
A/D converter stabilization time tADON 500 s
External RESET input pulse width tRL 1.5 — tCYC
Power-on RESET output pulse width
4064 cycle
16 cycle tPORL
tPORL
4064
16 —
—
tCYC
tCYC
Watchdog RESET output pulse width tDOGL 1.5 — tCYC
Watchdog time-out tDOG 6144 7168 tCYC
EPROM programming time tPROG 5 20 ms
EEPROM byte erase time
0 to 70 (standard)
– 40 to 85 (extended)
– 40 to 105 (industrial)
– 40 to 125 (automotive)
tERA
tERA
tERA
tERA
10
10
10
10
—
—
—
—
ms
ms
ms
ms
EEPROM byte program time(1)
0 to 70 (standard)
– 40 to 85 (extended)
– 40 to 105 (industrial)
– 40 to 125 (automotive)
tPROG
tPROG
tPROG
tPROG
10
10
15
20
—
—
—
—
ms
ms
ms
ms
Timer (see Figure E-12)
Resolution(2)
Input capture pulse width
Input capture pulse period
tRESL
tTH, tTL
tTLTL
4
125
—(3)
—
—
—
tCYC
ns
tCYC
Interrupt pulse width (edge-triggered) tILIH 125 — ns
Interrupt pulse period tILIL —(4) — tCYC
OSC1 pulse width tOH, tOL 90 — ns
MC68HC05B6 MOTOROLA
E-29
MC68HC705B16
14
(1) For bus frequencies less than 2 MHz, the internal RC oscillator should be used when
programming the EEPROM.
(2) Since a 2-bit prescaler in the timer must count four external cycles (tcyc), this is the limiting
factor in determining the timer resolution.
(3) The minimum period tTLTL should not be less than the number of cycle times it takes to
execute the capture interrupt service routine plus 24 tcyc.
(4) The minimum period tILIL should not be less than the number of cycle times it takes to
execute the interrupt service routine plus 21 tcyc.
Table E-13 Control timing for 3.3V operation
(VDD = 3.3Vdc  10%, VSS = 0 Vdc, TA = TL to TH)
Characteristic Symbol Min Max Unit
Frequency of operation
Crystal option
External clock option fOSC
fOSC
—
dc 2.0
2.0 MHz
MHz
Internal operating frequency (fOSC/2)
Crystal
External clock fOP
fOP
—
dc 1.0
1.0 MHz
MHz
Cycle time (see Figure 9-1) tCYC 1000 — ns
Crystal oscillator start-up time (see Figure 9-1) tOXOV — 100 ms
Stop recovery start-up time (crystal oscillator) tILCH 100 ms
RC oscillator stabilization time tADRC 100 ms
A/D converter stabilization time tADON 500 s
External
RESET input pulse width tRL 1.5 — tCYC
Power-on RESET output pulse width
4064 cycle
16 cycle tPORL
tPORL
4064
16 —
—
tCYC
tCYC
Watchdog RESET output pulse width tDOGL 1.5 — tCYC
Watchdog time-out tDOG 6144 7168 tCYC
EPROM programming time tPROG 5 20 ms
EEPROM byte erase time
0 to 70 (standard)
– 40 to 85 (extended)
– 40 to 105 (industrial)
– 40 to 125 (automotive)
tERA
tERA
tERA
tERA
30
30
30
30
—
—
—
—
ms
ms
ms
ms
EEPROM byte program time(1)
0 to 70 (standard)
– 40 to 85 (extended)
– 40 to 85 (industrial)
– 40 to 125 (automotive)
tPROG
tPROG
tPROG
tPROG
30
30
30
30
—
—
—
—
ms
ms
ms
ms
Timer (see Figure E-12)
Resolution(2)
Input capture pulse width
Input capture pulse period
tRESL
tTH, tTL
tTLTL
4
250
—(3)
—
—
—
tCYC
ns
tCYC
Interrupt pulse width (edge-triggered) tILIH 250 — ns
Interrupt pulse period tILIL —(4) — tCYC
OSC1 pulse width tOH, tOL 200 — ns
MOTOROLA
E-30 MC68HC705B16MC68HC705B16
14
Figure E-12 Timer relationship
External
signal
(TCAP1,
TCAP2)
tTLTL tTH tTL
MC68HC05B6 MOTOROLA
F-1
MC68HC05B32
14
F
MC68HC05B32
The MC68HC05B32 is a device similar to the MC68HC05B6, but with increased RAM and ROM
sizes. The entire MC68HC05B6 data sheet applies to the MC68HC05B32, with the exceptions
outlined in this appendix.
Features
• 31248 bytes User ROM
• No page zero ROM
• 528 bytes of RAM
• 638 bytes of self-check ROM
• 52-pin PLCC, 56-pin SDIP and 64-pin QFP packages
Note:
Preliminary electrical specifications for the MC68HC05B32 should be taken as being
identical to those for the MC68HC705B32. When silicon is fully available, the part will
be re-characterised and new data made available.
MOTOROLA
F-2 MC68HC05B6MC68HC05B32
14
Figure F-1 MC68HC05B32 block diagram
Port A
PA0
PA1
PA2
PA3
PA4
PA5
PA6
PA7
Port B
PB0
PB1
PB2
PB3
PB4
PB5
PB6
PB7
Port C
PC0
PC1
PC2/ECLK
PC3
PC4
PC5
PC6
PC7
16-bit
timer
Port D
PD0/AN0
PD1/AN1
PD2/AN2
PD3/AN3
PD4/AN4
PD5/AN5
PD6/AN6
PD7/AN7
Oscillator
COP watchdog
RESET
IRQ
VDD
VSS
OSC1
OSC2
M68HC05
CPU
SCI
A/D converter
PLM
TCAP1
TCAP2
TCMP1
TCMP2
VRH
VRL
RDI
SCLK
TDO
VPP1
256 bytes
EEPROM
Charge pump
2 / 32
PLMA D/A
PLMB D/A
8-bit
32 kbytes
ROM
528 bytes
static RAM
638 bytes
VPP6
self-check ROM
MC68HC05B6 MOTOROLA
F-3
MC68HC05B32
14
Figure F-2 Memory map of the MC68HC05B32
MOTOROLA
F-4 MC68HC05B6MC68HC05B32
14
(1) This bit is set each time there is a power-on reset.
(2) The state of the WDOG bit after reset is dependent upon the mask option selected; 1 = watchdog enabled, 0 = watchdog disabled.
(3) This register is implemented in EEPROM; therefore reset has no effect on the individual bits.
(4) This register is implemented in ROM; therefore reset has no effect on the individual bits.
Table F-1 Register outline
Register name Address bit 7 bit 6 bit 5 bit 4 bit 3 bit 2 bit 1 bit 0 State on
reset
Port A data (PORTA) $0000 Undefined
Port B data (PORTB) $0001 Undefined
Port C data (PORTC) $0002 PC2/
ECLK Undefined
Port D data (PORTD) $0003 PD7 PD6 PD5 PD4 PD3 PD2 PD1 PD0 Undefined
Port A data direction (DDRA) $0004 0000 0000
Port B data direction (DDRB) $0005 0000 0000
Port C data direction (DDRC) $0006 0000 0000
EEPROM/ECLK control $0007 0 0 0 0 ECLK E1ERA E1LAT E1PGM 0000 0000
A/D data (ADDATA) $0008 0000 0000
A/D status/control (ADSTAT) $0009 COCO ADRC ADON 0 CH3 CH2 CH1 CH0 0000 0000
Pulse length modulation A (PLMA) $000A 0000 0000
Pulse length modulation B (PLMB) $000B 0000 0000
Miscellaneous $000C POR(1) INTP INTN INTE SFA SFB SM WDOG(2) ?001 000?
SCI baud rate (BAUD) $000D SPC1 SPC0 SCT1 SCT0 SCT0 SCR2 SCR1 SCR0 00uu uuuu
SCI control 1 (SCCR1) $000E R8 T8
M WAKE CPOL CPHA LBCL Undefined
SCI control 2 (SCCR2) $000F TIE TCIE RIE ILIE TE RE RWU SBK 0000 0000
SCI status (SCSR) $0010 TDRE TC RDRF IDLE OR NF FE 1100 000u
SCI data (SCDR) $0011 0000 0000
Timer control (TCR) $0012 ICIE OCIE TOIE FOLV2 FOLV1 OLV2 IEDG1 OLVL1 0000 00u0
Timer status (TSR) $0013 ICF1 OCF1 TOF ICF2 OCF2 Undefined
Input capture high 1 $0014 Undefined
Input capture low 1 $0015 Undefined
Output compare high 1 $0016 Undefined
Output compare low 1 $0017 Undefined
Timer counter high $0018 1111 1111
Timer counter low $0019 1111 1100
Alternate counter high $001A 1111 1111
Alternate counter low $001B 1111 1100
Input capture high 2 $001C Undefined
Input capture low 2 $001D Undefined
Output compare high 2 $001E Undefined
Output compare low 2 $001F Undefined
Options (OPTR)(3) $0100 EE1P SEC Not affected
Mask option register (MOR)(4) $7FDE RTIM RWAT WWAT PBPD PCPD Not affected
MC68HC05B6 MOTOROLA
G-1
MC68HC705B32
14
G
MC68HC705B32
The MC68HC705B32 is an EPROM version of the MC68HC05B32, with the ROM replaced by a
similar amount of EPROM and with a bootstrap mode instead of a self-check mode. The entire
MC68HC05B6 data sheet applies to the MC68HC705B32, with the exceptions outlined in this
appendix.
Features
• 31248 bytes user EPROM
• No page zero EPROM at $20–$4F
• 528 bytes of RAM
• 638 bytes bootstrap ROM instead of 432 bytes of self-check ROM
• Simultaneous programming of up to 16 bytes of EPROM
• 52-pin PLCC, 56-pin SDIP and 64-pin QFP packages
Note:
The electrical characteristics from the MC68HC05B6 data sheet should not be used for
the MC68HC705B32. Data specific to this device can be found in Section G.2.6 and
Section G.2.8.
MOTOROLA
G-2 MC68HC05B6MC68HC705B32
14
Figure G-1 MC68HC705B32 block diagram
Port A
PA0
PA1
PA2
PA3
PA4
PA5
PA6
PA7
Port B
PB0
PB1
PB2
PB3
PB4
PB5
PB6
PB7
Port C
PC0
PC1
PC2/ECLK
PC3
PC4
PC5
PC6
PC7
16-bit
timer
Port D
PD0/AN0
PD1/AN1
PD2/AN2
PD3/AN3
PD4/AN4
PD5/AN5
PD6/AN6
PD7/AN7
Oscillator
COP watchdog
RESET
IRQ
VDD
VSS
OSC1
OSC2
M68HC05
CPU
SCI
A/D converter
PLM
TCAP1
TCAP2
TCMP1
TCMP2
VRH
VRL
RDI
SCLK
TDO
VPP1
256 bytes
EEPROM
Charge pump
2 / 32
PLMA D/A
PLMB D/A
8-bit
32 kbytes
EPROM
528 bytes
static RAM
638 bytes
VPP6
bootstrap ROM
MC68HC05B6 MOTOROLA
G-3
MC68HC705B32
14
Figure G-2 Memory map of the MC68HC705B32
MOTOROLA
G-4 MC68HC05B6MC68HC705B32
14
(1) This bit is set each time there is a power-on reset.
(2) The state of the WDOG bit after reset is dependent upon the mask option selected; 1=watchdog enabled, 0=watchdog disabled.
(3) This register is implemented in EEPROM; therefore reset has no effect on the individual bits.
(4) This register is implemented in EPROM; therefore reset has no effect on the individual bits.
Table G-1 Register outline
Register name Address bit 7 bit 6 bit 5 bit 4 bit 3 bit 2 bit 1 bit 0 State on
reset
Port A data (PORTA) $0000 Undefined
Port B data (PORTB) $0001 Undefined
Port C data (PORTC) $0002 PC2/
ECLK Undefined
Port D data (PORTD) $0003 PD7 PD6 PD5 PD4 PD3 PD2 PD1 PD0 Undefined
Port A data direction (DDRA) $0004 0000 0000
Port B data direction (DDRB) $0005 0000 0000
Port C data direction (DDRC) $0006 0000 0000
EPROM/EEPROM/ECLK control $0007
0 E6LAT E6PGM ECLK E1ERA E1LAT E1PGM u000 0000
A/D data (ADDATA) $0008 0000 0000
A/D status/control (ADSTAT) $0009 COCO ADRC ADON 0 CH3 CH2 CH1 CH0 0000 0000
Pulse length modulation A (PLMA) $000A 0000 0000
Pulse length modulation B (PLMB) $000B 0000 0000
Miscellaneous $000C POR(1) INTP INTN INTE SFA SFB SM WDOG(2) ?001 000?
SCI baud rate (BAUD) $000D SPC1 SPC0 SCT1 SCT0 SCT0 SCR2 SCR1 SCR0 00uu uuuu
SCI control 1 (SCCR1) $000E R8 T8 M WAKE CPOL CPHA LBCL Undefined
SCI control 2 (SCCR2) $000F TIE TCIE RIE ILIE TE RE RWU SBK 0000 0000
SCI status (SCSR) $0010 TDRE TC RDRF IDLE OR NF FE 1100 000u
SCI data (SCDR) $0011 0000 0000
Timer control (TCR) $0012 ICIE OCIE TOIE FOLV2 FOLV1 OLV2 IEDG1 OLVL1 0000 00u0
Timer status (TSR) $0013 ICF1 OCF1 TOF ICF2 OCF2 Undefined
Input capture high 1 $0014 Undefined
Input capture low 1 $0015 Undefined
Output compare high 1 $0016 Undefined
Output compare low 1 $0017 Undefined
Timer counter high $0018 1111 1111
Timer counter low $0019 1111 1100
Alternate counter high $001A 1111 1111
Alternate counter low $001B 1111 1100
Input capture high 2 $001C Undefined
Input capture low 2 $001D Undefined
Output compare high 2 $001E Undefined
Output compare low 2 $001F Undefined
Options (OPTR)(3) $0100 EE1P SEC Not affected
Mask option register (MOR)(4) $7FDE RTIM RWAT WWAT PBPD PCPD Not affected
MC68HC05B6 MOTOROLA
G-5
MC68HC705B32
14
G.1 EPROM
Figure G-2 shows the MC68HC705B32 memory map. The device has a total of 31232 bytes of
EPROM (including 14 bytes for User vectors) and 256 bytes of EEPROM.
The EPROM array is supplied by the VPP6 pin in both read and program modes. Typically the
user’s software will be loaded into a programming board where VPP6 is controlled by one of the
bootstrap loader routines. It will then be placed in an application where no programming occurs.
In this case the VPP6 pin should be hardwired to VDD.
Warning: A minimum VDD voltage must be applied to the VPP6 pin at all times, including
power-on. Failure to do so could result in permanent damage to the device.
G.1.1 EPROM read operation
The execution of a program in the EPROM address range or a load from the EPROM are both
read operations. The E6LAT bit in the EPROM/EEPROM control register should be cleared to ‘0’
which automatically resets the E6PGM bit. In this way the EPROM is read like a nor mal ROM.
Reading the EPROM with the E6LAT bit set will give data that does not correspond to the actual
memory content. As interrupt vectors are in EPROM, they will not be loaded when E6LAT is set.
Similarly, the bootstrap ROM routines cannot be executed when E6LAT is set. In read mode, the
VPP6 pin must be at the VDD level. When entering the STOP mode, the EPROM is automatically
set to the read mode.
Note:
An erased byte reads as $00.
G.1.2 EPROM program operation
Typically, the EPROM will be programmed by the bootstrap routines resident in the on-chip R OM.
However, the user program can be used to program some EPROM locations if the proper
procedure is followed. In particular, the programming sequence must be running in RAM, as the
EPROM will not be available for code execution while the E6LAT bit is set. The VPP6 switching
must occur externally after EPGM is set, for example under control of a signal generated on a pin
by the programming routine.
Note:
When the part becomes a PROM, only the cumulative programming of bits to logic ‘1’
is possible if multiple programming is made on the same byte.
To allow simultaneous programming of up to sixteen b ytes, these bytes must be in the same group
of addresses which share the same most significant address bits; only the f our LSBs can change.
MOTOROLA
G-6 MC68HC05B6MC68HC705B32
14
G.1.3 EPROM/EEPROM control register
E6LAT — EPROM programming latch enable bit
1 (set) – Address and up to sixteen data bytes can be latched into the EPROM
for further programming providing the E6PGM bit is cleared.
0 (clear) – Data can be read from the EPROM or firmware ROM; the E6PGM bit
is reset to zero when E6LAT is ‘0’.
STOP, power-on and external reset clear the E6LAT bit.
Note:
After the tERA1 erase time or tPROG1 programming time, the E6LAT bit has to be reset
to zero in order to clear the E6PGM bit.
E6PGM — EPROM program enable bit
This bit is the EPROM program enable bit. It can be set to ‘1’ to enable programming only after
E6LAT is set and at least one byte is written to the EPROM. It is not possible to clear this bit using
software but clearing E6LAT will always clear E6PGM.
Note:
All combinations are not shown in the above table, since the E6PGM bit is cleared when
the E6LAT bit is at zero, and will result in a read condition.
ECLK
See Section 4.3.
Address bit 7 bit 6 bit 5 bit 4 bit 3 bit 2 bit 1 bit 0 State
on reset
EPROM/EEPROM/ECLK control $0007 0 E6LAT E6PGM ECLK E1ERA E1LAT E1PGM u000 0000
Table G-2 EPROM control bits description
E6LAT E6PGM Description
0 0 Read/execute in EPROM
1 0 Ready to write address/data to EPROM
1 1 programming in progress
MC68HC05B6 MOTOROLA
G-7
MC68HC705B32
14
E1ERA — EEPROM erase/programming bit
Providing the E1LAT and E1PGM bits are at logic one, this bit indicates whether the access to the
EEPROM is for erasing or programming purposes.
1 (set) – An erase operation will take place.
0 (clear) – A programming operation will take place.
Once the program/erase EEPROM address has been selected, E1ERA cannot be changed.
E1LAT — EEPROM programming latch enable bit
1 (set) – Address and data can be latched into the EEPROM for further
program or erase operations, providing the E1PGM bit is cleared.
0 (clear) – Data can be read from the EEPROM. The E1ERA bit and the
E1PGM bit are reset to zero when E1LAT is ‘0’.
STOP, power-on and external reset clear the E1LAT bit.
Note:
After the tERA1 erase time or tPROG1 programming time, the E1LAT bit has to be reset
to zero in order to clear the E1ERA bit and the E1PGM bit.
E1PGM — EEPROM charge pump enable/disable
1 (set) – Internal charge pump generator switched on.
0 (clear) – Internal charge pump generator switched off.
When the charge pump generator is on, the resulting high voltage is applied to the EEPROM array.
This bit cannot be set before the data is selected, and once this bit has been set it can only be
cleared by clearing the E1LAT bit.
A summary of the effects of setting/clearing bits 0, 1 and 2 of the control register are given in Table G-3.
Note:
The E1PGM and E1ERA bits are cleared when the E1LAT bit is at zero.
Table G-3 EEPROM control bits description
E1ERA E1LAT E1PGM Description
0 0 0 Read condition
0 1 0 Ready to load address/data for program/erase
0 1 1 Byte programming in progress
1 1 0 Ready for byte erase (load address)
1 1 1 Byte erase in progress
MOTOROLA
G-8 MC68HC05B6MC68HC705B32
14
G.1.4 Mask option register
RTIM
This bit can modify the time tPORL, where the RESET pin is kept low after a power-on reset.
1 (set) – tPORL = 16 cycles.
0 (clear) – tPORL = 4064 cycles.
RWAT
This bit can modify the status of the watchdog counter after reset. Usually, the watchdog system
is disabled after power-on or external reset but when this bit is set, it will be active immediately
after the following resets (except in bootstrap mode).
WWAT
This bit can modify the status of the watchdog counter in WAIT mode. Normally, the watchdog
system is disabled in WAIT mode but when this bit is set, the watchdog will be active in WAIT
mode.
PBPD
This bit, when programmed, connects a resistiv e pull-down on all 8 pins of port B. This pull-down,
RPD, is active on a given pin only while it is an input.
PCPD
This bit, when programmed, connects a resistiv e pull-down on all 8 pins of port C. This pull-down,
RPD, is active on a given pin only while it is an input.
(1) Because this register is implemented in EPROM, reset has no effect on the individual bits.
Address bit 7 bit 6 bit 5 bit 4 bit 3 bit 2 bit 1 bit 0 State
on reset
Mask option register (MOR)(1) $7FDE
RTIM RWAT WWAT PBPD PCPD Not affected
MC68HC05B6 MOTOROLA
G-9
MC68HC705B32
14
G.1.5 Options register (OPTR)
EE1P – EEPROM protect bit
In order to achieve a higher degree of protection, the EEPROM is effectively split into two parts,
both working from the VPP1 charge pump. Part 1 of the EEPROM array (32 bytes from $0100 to
$011F) cannot be protected; part 2 (224 bytes from $0120 to $01FF) is protected by the EE1P bit
of the options register.
1 (set) – Part 2 of the EEPROM array is not protected; all 256 bytes of
EEPROM can be accessed for any read, erase or programming
operations.
0 (clear) – Part 2 of the EEPROM array is protected; any attempt to erase or
program a location will be unsuccessful.
When this bit is set to 1 (erased), the protection will remain until the next power-on or external
reset. EE1P can only be written to ‘0’ when the E1LAT bit in the EEPROM control register is set.
Note:
The EEPROM1 protect function is disabled while in bootstrap mode.
SEC — Secure bit
This bit allows the EPROM and EEPROM1 to be secured from external access. When this bit is
in the erased state (set), the EPROM and EEPROM1 content is not secured and the device may
be used in non user mode. When the SEC bit is programmed to ‘zero’, the EPROM and
EEPROM1 content is secured b y prohibiting entry to the non user mode. To deactivate the secure
bit, the EPROM has to be er ased by exposure to a high density ultraviolet light, and the de vice has
to be entered into the EPROM erase verification mode with PD1 set. When the SEC bit is
changed, its new value will have no effect until the next power-on or external reset.
1 (set) – EEPROM/EPROM not protected.
0 (clear) – EEPROM/EPROM protected.
(1) Because this register is implemented in EEPROM, reset has no effect on the individual bits.
Address bit 7 bit 6 bit 5 bit 4 bit 3 bit 2 bit 1 bit 0 State
on reset
Options (OPTR)(1) $0100
EE1P SEC Not affected
MOTOROLA
G-10 MC68HC05B6MC68HC705B32
14
G.2 Bootstrap mode
The 432 bytes of self-chec k firmware on the MC68HC05B6 are replaced by 654 b ytes of bootstrap
firmware. A detailed description of the modes of operation within bootstrap mode is given below.
The bootstrap program in mask ROM address locations $0200 to $024F, $03B0 to $3FFF, $7E00
to $7FDD and $7FE0 to $7FEF can be used to program the EPROM and the EEPROM, to check
if the EPROM is erased or to load and execute data in RAM.
After reset, while going to the bootstrap mode, the vector located at address $7FEE and $7FEF
(RESET) is fetched to start execution of the bootstrap program. To place the part in bootstrap
mode, the IRQ pin should be at 2xVDD with the TCAP1 pin ‘high’ during transition of the RESET
pin from low to high. The hold time on the IRQ and TCAP1 pins is two clock cycles after the
external RESET pin is brought high.
When the MC68HC705B32 is placed in the bootstrap mode, the bootstrap reset vector will be
fetched and the bootstrap firmware will start to execute. Table G-4 shows the conditions required
to enter each level of bootstrap mode on the rising edge of RESET.
The bootstrap program will first copy part of itself in RAM (except ‘RAM parallel load’), as the
program cannot be executed in ROM during verification/programming of the EPROM. It will then
set the TCMP1 output to a logic high level, unlike the MC68HC05B6 which k eeps TCMP1 low. This
can be used to distinguish between the two circuits and, in particular, for selection of the VPP le vel
and current capability.
Table G-4 Mode of operation selection
IRQ pin TCAP1 pin PD1 PD2 PD3 PD4 Mode
VSS to VDD VSS to VDD x x x x Single chip
+ 9 Volts VDD 0 0 0 x Erased EPROM verification
+ 9 Volts VDD 1 0 0 0 Erased EPROM verification; erase EEPROM;
EPROM/EEPROM parallel program/verify
+ 9 Volts VDD 0 1 0 0 Erased EPROM verification;
no EEPROM erase if SEC is zero (parallel mode)
+ 9 Volts VDD 1 1 0 0 Erased EPROM verification; erase EEPROM;
EPROM parallel program/verify (no E2)
+ 9 Volts VDD x 1 1 0 Jump to start of RAM ($0051); SEC bit = 0
+ 9 Volts VDD 0 1 0 1 EPROM and EEPROM verification; SEC bit = 0 (parallel mode)
+ 9 Volts VDD x x 1 1 Serial RAM load/e xecute – similar to MC68HC05B6 but can fill RAM
I, II and III
x = Don’t care
MC68HC05B6 MOTOROLA
G-11
MC68HC705B32
14
Figure G-3 Modes of operation flow chart (1 of 2)
Red LED on
TCAP1 set?
SEC bit active?PD3 set?
Reset
User mode
Red LED on
Non-user mode
Non-user mode
N
YY
Y
Y
N
Y
N
N
Bootstrap mode Parallel E/EEPROM bootstrap
N
PD4 set?
Y
Erased EPROM verification
Serial RAM
load/execute
N
PD2 set?
Y
N
Jump to RAM
($0051)
PD2 set?
N
PD1 set?
Y
N
SEC bit active? Red LED on
Y
N
PD4 set? Y
EPR OM er ased?
N
Y
Y
Green LED on
PD1 set?
N
Erase EEPROM1
Red LED off
N
A
B
C
SEC bit active?
IRQ at 2xV DD?
MOTOROLA
G-12 MC68HC05B6MC68HC705B32
14
Figure G-4 Modes of operation flow chart (2 of 2)
Data v erified?
Y
PD2 set?
N
N
Red LED on
ABase address = $400
(EPROM only)
Base address = $100
(EPR OM and EEPROM)
Y
N
Green LED on
B
C
PD2 set? NY
Base address = $400
(EPROM only)
Base address = $400
(EPROM only)
MC68HC05B6 MOTOROLA
G-13
MC68HC705B32
14
G.2.1 Erased EPROM verification
If a non $00 byte is detected, the red LED will be turned on and the routine will stop (see Figure
G-3 and Figure G-4). Only when the whole EPROM content is verified as erased will the green
LED be turned on. PD1 is then checked. If PD1=0, the bootstrap program stops here and no
programming occurs until such time as a high level is sensed on PD1. If PD1 = 1, the bootstrap
program proceeds to erase the EEPROM1 for a nominal 2.5 seconds (4.0 MHz crystal). It is then
checked for complete erasure; if any EEPROM byte is not erased, the program will stop before
erasing the SEC b yte. When both EPROM and EEPR OM1 are completely erased and the security
bit is cleared the programming operation can be performed. A schematic diagram of the circuit
required for erased EPROM verification is shown in Figure G-7.
G.2.2 EPROM/EEPROM parallel bootstrap
Within this mode there are various subsections which can be utilised by correctly configuring the
port pins shown in Table G-4.
The erased EPROM verification program will be executed first as described in Section G.2.1.
When PD2=0, the programming time is set to 5 milliseconds with the bootstr ap program and v erify
for the EPROM taking approximately 15 seconds. The EPROM will be loaded in increasing
address order with non EPROM segments being skipped by the loader. Simultaneous
programming is performed by reading sixteen bytes of data before actual programming is
performed, thus dividing the loading time of the internal EPROM by 16. If any block of 16 EPROM
bytes or 1 EEPROM byte of data is in the erased state, no programming takes place, thus
speeding up the execution time.
Parallel data is entered through Port A, while the 15-bit address is output on port B, PC0 to PC4
and TCMP1 and TCMP2. If the data comes from an external EPROM, the handshake can be
disabled by connecting together PC5 and PC6. If the data is supplied by a parallel interface,
handshake will be provided by PC5 and PC6 according to the timing diagram of Figure G-5 (see
also Figure G-6).
During programming, the green LED will flash at about 3 Hz.
Upon completion of the programming operation, the EPROM and EEPROM1 content will be
checked against the external data source. If programming is verified the green LED will stay on,
while an error will cause the red LED to be turned on. Figure G-7 is a schematic diagram of a
circuit which can be used to program the EPROM or to load and execute data in the RAM.
Note:
The entire EPROM and EEPROM1 can be loaded from the external source; if it is
desired to leave a segment undisturbed, the data for this segment should be all $00s
for EPROM data and all $FFs for EEPROM1 data.
MOTOROLA
G-14 MC68HC05B6MC68HC705B32
14
Figure G-5 Timing diagram with handshake
Figure G-6 Parallel EPROM loader timing diagram
Data read Data read
Address
HDSK out
(PC5)
Data
HDSK in
(PC6)
F29
tCOOE
tADE tDHE
Address
Data
tADE tDHE
tADE tDHE
tADE tDHE
tCOOE tCOOE tCDDE
tADE max (address to data delay) 5 machine cycles
tDHA min (data hold time) 14 machine cycles
tCOOE (load cycle time) 117 machine cycles < tCOOE < 150 machine cycles
tCDDE (programming cycle time) tCOOE + tPROG (5ms nominal for EPROM; 10ms for EEPROM1))
1 machine cycle = 1/(2f0(Xtal))
MC68HC05B6 MOTOROLA
G-15
MC68HC705B32
14
Figure G-7 EPROM parallel bootstrap schematic diagram
VCC
281
VPP PGM
27
PB0
PB1
PB2
PB3
PB4
PB5
PB6
PB7
PA0
PA1
PA2
PA3
PA4
PA5
PA6
PA7
VDD
OSC1
OSC2
TCAP1
IRQ
RESET
VSS
A0
A1
A2
A3
A4
A5
A6
A7
D0
D1
D2
D3
D4
D5
D6
D7
GND OE
14 22
10
9
8
7
6
5
4
26
12
13
15
16
17
18
19
11
3
+5V
1
2
P1 GND
+5V
100F
22pF
4.0 MHz
1N914
1k
1.0F
22pF
100k
1N914
RESET RUN
0.01F
TDO
SCLK
RDI
VRL
TCAP2
PD7
PD6
PD5
PD3
PD2
PD1
PD0
PD4
+5V
3VPP
VPP6
PC7
PC5
PC4
PC3
PC2
PC1
PC0
PC6
24
21
23
2
A9
A8
A10
A12
CE
A11
A12
A11
A10
A9
A8
HDSK out
HDSK in
Short circuit if
handshake not used
100 k
NC
TCMP1
TCMP2
PLMA
PLMB
470
470
red LED
green LED
4k7
4k7
12 k
BC239C
BC309C
10k 
27C256
+
+
VRH
red LED — programming failed
green LED — programming OK
25
1nF
1N5819
1 k
+
RAM
EPROM
green LED — EPROM erased
47F +
Erase check & boot
EPROM erase
check
VPP1
red LED — EPROM not erased
Boot
Erase check
A13
20
MC68HC705B32
MCU
A14
Verify
Program
EPROM
EPROM
MOTOROLA
G-16 MC68HC05B6MC68HC705B32
14
G.2.3 Serial RAM loader
This mode is similar to the RAM load/execute program for the MC68HC05B6 described in Section
2.2, with the additional f eatures listed below. Table G-4 shows the entry conditions required for this
mode.
If the first byte is less than $B0, the bootloader behaves exactly as the MC68HC05B6, i.e. count
byte followed by data stored in $0050 to $00FF. If the count byte is larger than RAM I (176 bytes)
then the code continues to fill RAM II then RAM III. In this case the count byte is ignored and the
program execution begins at $0051 once the total RAM area is filled or if no data is received for 5
milliseconds.
The user must take care when using branches or jumps as his code will be relocated in RAM I, II
and III. If the user intends to use the stack in his prog ram, he should send NOP’s to fill the desired
stack area.
In the RAM bootloader mode, all interrupt vectors are mapped to pseudo-vectors in RAM (see
Table G-5). This allows programmers to use their own service-routine addresses. Each
pseudo-vector is allowed three bytes of space rather than the two bytes for normal vectors,
because an explicit jump (JMP) opcode is needed to cause the desired jump to the users
service-routine address.
G.2.3.1 Jump to start of RAM ($0051)
The Jump to start of RAM program will be executed when bring the device out of reset with PD2
and PD3 at ‘1’ and PD4 at ‘0’.
Table G-5 Bootstrap vector targets in RAM
Vector targets in RAM
SCI interrupt $0063
Timer overflow $0060
Timer output compare $005D
Timer input capture $005A
IRQ $0057
SWI $0054
MC68HC05B6 MOTOROLA
G-17
MC68HC705B32
14
Figure G-8 RAM load and execute schematic diagram
Green LED — programming ended
Flashing green LED — programming
40
VPP6
PC7
PB0
PB1
PB2
PB3
PB4
PB5
PB6
PB7
PA0
PA1
PA2
PA3
PA4
PA5
PA6
PA7
VDD
OSC1
OSC2
TCAP1
IRQ
RESET
VSS
1
2
P1 GND
+5V
1N914
1k
1.0F
100k
1N914
RESET RUN
0.01F
3VPP
PC5
PC4
PC3
PC2
PC1
PC0
PC6
PLMA
PLMB
470
470
Red LED
Green LED
+
+
VRH
22F
22F
22F
2 x 3K 1
23
4
8
6
7
5
11
1213
14
15
16
53
2
1
22F
RS232
Connector MAX
232
+5V
9600 BD
8-bit
no parity
19
18
20
21
50
52
39
38
37
36
35
34
33
32
31
30
29
28
27
26
25
24
14
13
12
5
4
43
44
45
46
47
48
49
23
2
1
51
22 8 10
41 7
VRL
TCAP2
TCMP1
TCMP2
SCLK
NC
10nF 47F
PD0
PD4
PD1
PD2
PD5
PD6
PD7
+
+
+
+
22pF 4.0 MHz
22pF
4k7
4k7 12 k
BC239C
BC309C
10k 
1nF
1N5819
1 k
+
Serial boot
Erase check
47F +
PD3
RDI
TDO
Erase check
Red LED — EPROM not erased
Green LED — EPROM erased
Serial boot &
serial boot
Erase check and serial boot
EPROM erase check
VPP1
3
U2 MC68HC705B32
MCU (socket)
MOTOROLA
G-18 MC68HC05B6MC68HC705B32
14
Figure G-9 Parallel RAM loader timing diagram
tADR tDHR
Address
Data
tCR
PD4 tEXR max
tHO
tHI max
PC5 out
PC6 in
tADR max (address to data delay; PC6=PC5) 16 machine cycles
tDHR min (data hold time) 4 machine cycles
tCR (load cycle time; PC6=PC5) 49 machine cycles
tHO (PC5 handshake out delay) 5 machine cycles
tHI max (PC6 handshake in, data hold time) 10 machine cycles
tEXR max (max delay for transition to be recognised during this cycle; PC6=PC5 30 machine cycles
1 machine cycle = 1/(2f0(Xtal))
MC68HC05B6 MOTOROLA
G-19
MC68HC705B32
14
G.2.4 Maximum ratings
Note:
This device contains circuitry designed to protect against damage due to high
electrostatic voltages or electric fields. However, it is recommended that normal
precautions be taken to avoid the application of any voltages higher than those given
in the maximum ratings table to this high impedance circuit. For maximum reliability all
unused inputs should be tied to either VSS or VDD.
(1) All voltages are with respect to VSS.
(2) Maximum current drain per pin is for one pin at a time, limited by an external resistor.
Table G-6 Maximum ratings
Rating Symbol Value Unit
Supply voltage(1) VDD – 0.5 to +7.0 V
Input voltage VIN VSS – 0.5 to VDD + 0.5 V
Input voltage
– Self-check mode (
IRQ pin only) VIN VSS – 0.5 to 2VDD + 0.5 V
Operating temperature range
– Standard (MC68HC705B32)
– Extended (MC68HC705B32C)
– Industrial (MC68HC705B32V)
– Automotive (MC68HC705B32M)
TATL to TH
0 to +70
–40 to +85
–40 to +105
–40 to +125
C
Storage temperature range TSTG – 65 to +150 C
Current drain per pin (e xcluding VDD and VSS) (2)
– Source
– Sink ID
IS
25
45 mA
mA
MOTOROLA
G-20 MC68HC05B6MC68HC705B32
14
G.2.5 Thermal characteristics and power considerations
The average chip junction temperature, TJ, in degrees Celsius can be obtained from the following
equation:
[4]
where:
TA = Ambient temperature (C)
θJA = Package thermal resistance, junction-to-ambient (C/W)
PD = PINT + PI/O (W)
PINT = Internal chip power = IDD • VDD (W)
PI/O = Power dissipation on input and output pins (user determined)
An approximate relationship between PD and TJ (if PI/O is neglected) is:
[5]
Solving equations [1] and [2] for K gives:
[6]
where K is a constant f or a particular part. K can be determined by measuring PD (at equilibrium)
for a known TA. Using this value of K, the values of PD and TJ can be obtained for any value of TA
by solving the above equations. The package thermal characteristics are shown in Table G-7.
Table G-7 Package thermal characteristics
Characteristics Symbol Value Unit
Thermal resistance
– 64-pin quad flat package
θ
JA 50 C/W
– Plastic 56 pin shrink DIL package
θ
JA 50 C/W
– Plastic 52 pin PLCC package
θ
JA 50 C/W
Figure G-10 Equivalent test load
TJTAPD
θJA
•( )+=
PDK
TJ
273+
---------------------
=
K PDTA273+( )• θJA PD
2
•+=
VDD = 4.5/3.0 V
R2
R1C
Test
point
Voltage Pins R1 R2 C
4.5V PA0–7, PB0–7, PC0–7 3.26k 2.38k 50pF
3.0V PA0–7, PB0–7, PC0–7 10.91k 6.32k 50pF
MC68HC05B6 MOTOROLA
G-21
MC68HC705B32
14
G.2.6 DC electrical characteristics
Table G-8 DC electrical characteristics for 5V operation
(VDD = 5 Vdc  10%, VSS = 0 Vdc, TA = TL to TH)
Characteristic(1) Symbol Min Typ(2) Max Unit
Output voltage
ILOAD = – 10 A
ILOAD = +10 A VOH
VOL
VDD – 0.1
——
——
0.1 V
Output high voltage (ILOAD = 0.8mA)
PA0–7, PB0–7, PC0–7, TCMP1, TCMP2
Output high voltage (ILOAD = 1.6mA)
TDO, SCLK, PLMA, PLMB
VOH
VOH
VDD – 0.8
VDD – 0.8
VDD – 0.4
VDD – 0.4
—
—
V
Output low voltage (ILOAD = 1.6mA)
PA0–7, PB0–7, PC0–7, TCMP1, TCMP2,
TDO, SCLK, PLMA, PLMB
Output low voltage (ILOAD = 1.6mA)
RESET
VOL
VOL
— 0.1
0.4
0.4
1
V
Input high voltage
PA0–7, PB0–7, PC0–7, PD0–7, OSC1,
IRQ, RESET, TCAP1, TCAP2, RDI VIH 0.7VDD — VDD V
Input low voltage
PA0–7, PB0–7, PC0–7, OSC1, IRQ,RESET,
TCAP1, TCAP2, RDI VIL VSS — 0.2VDD V
Supply current(3)
RUN (SM = 0) (See Figure 11-2)
RUN (SM = 1) (See Figure 11-3)
WAIT (SM = 0) (See Figure 11-4)
WAIT (SM = 1) (See Figure 11-5)
STOP 0 to 70 (standard)
– 40 to 85 (extended)
– 40 to 105 (extended)
– 40 to 125 (automotive)
IDD
IDD
IDD
IDD
IDD
IDD
IDD
IDD
—
—
—
—
—
—
—
—
6
1.5
2
1
10
20
60
60
TBD
TBD
TBD
TBD
TBD
TBD
TBD
TBD
mA
mA
mA
mA
A
A
A
A
EPROM
Absolute maximum voltage
Programming voltage
Programming current
Read voltage
VPP6 max
VPP6
IPP6
VPP6R
VDD
14.5
—
VDD
—
15.5
50
VDD
18
16
64
VDD10%
V
V
mA
V
High-Z leakage current
PA0–7, PB0–7, PC0–7, TDO, RESET, SCLK IIL — 0.2 1 A
Input current
Port B and port C pull-down (VIN=VIH) IRPD 80 A
Input current (0 to 70)
IRQ, OSC1, TCAP1, TCAP2, RDI,
PD0/AN0-PD7/AN7 (channel not selected) IIN — 0.2 1 A
Input current (– 40 to 125)
IRQ, OSC1, TCAP1, TCAP2, RDI,
PD0/AN0-PD7/AN7 (channel not selected) IIN — — 5 A
MOTOROLA
G-22 MC68HC05B6MC68HC705B32
14
(1) All IDD measurements taken with suitable decoupling capacitors across the power supply to suppress the
transient switching currents inherent in CMOS designs (see Section 2).
(2) Typical values are at mid point of voltage range and at 25C only.
(3) RUN and WAIT IDD: measured using an external square-wave clock source (fOSC =4.2MHz); all inputs 0.2 V
from rail; no DC loads; maximum load on outputs 50pF (20pF on OSC2).
STOP /WAIT IDD: all ports configured as inputs; VIL = 0.2 V and VIH = VDD – 0.2 V: STOP IDD measured with
OSC1 = VDD.
WAIT IDD is affected linearly by the OSC2 capacitance.
Capacitance
Ports (as input or output),
RESET, TDO, SCLK
IRQ, TCAP1, TCAP2, OSC1, RDI
PD0/AN0–PD7/AN7 (A/D off)
PD0/AN0–PD7/AN7 (A/D on)
COUT
COUT
CIN
CIN
—
—
—
—
—
—
12
22
12
8
—
—
pF
pF
pF
pF
Table G-8 DC electrical characteristics for 5V operation (Continued)
(VDD = 5 Vdc  10%, VSS = 0 Vdc, TA = TL to TH)
Characteristic(1) Symbol Min Typ(2) Max Unit
MC68HC05B6 MOTOROLA
G-23
MC68HC705B32
14
(1) All IDD measurements taken with suitable decoupling capacitors across the power supply to suppress the
transient switching currents inherent in CMOS designs (see Section 2).
(2) Typical values are at mid point of voltage range and at 25C only.
(3) RUN and WAIT IDD: measured using an external square-wave clock source (fOSC =2.1MHz); all inputs 0.2 V
from rail; no DC loads; maximum load on outputs 50pF (20pF on OSC2).
STOP /WAIT IDD: all ports configured as inputs; VIL = 0.2 V and VIH = VDD – 0.2 V: STOP IDD measured with
OSC1 = VDD.
WAIT IDD is affected linearly by the OSC2 capacitance.
Table G-9 DC electrical characteristics for 3.3V operation
(VDD = 3.3Vdc  10%, VSS = 0Vdc, TA = TL to TH)
Characteristic(1) Symbol Min Typ(2) Max Unit
Output voltage
ILOAD = – 10 A
ILOAD = +10 A VOH
VOL VDD – 0.1
——
——
0.1 V
Output high voltage (ILOAD = 0.8mA)
PA0–7, PB0–7, PC0–7, TCMP1, TCMP2
Output high voltage (ILOAD = 1.6mA)
TDO, SCLK, PLMA, PLMB
VOH
VOH
VDD – 0.3
VDD – 0.3
VDD – 0.1
VDD – 0.1
—
—V
Output low voltage (ILOAD = 1.6mA)
PA0–7, PB0–7, PC0–7, TCMP1, TCMP2,
TDO, SCLK, PLMA, PLMB
Output low voltage (ILOAD = 1.6mA)
RESET
VOL
VOL
— 0.1
0.2
0.4
0.6 V
Input high voltage
PA0–7, PB0–7, PC0–7, PD0–7, OSC1,
IRQ, RESET, TCAP1, TCAP2, RDI VIH 0.7VDD — VDD V
Input low voltage
PA0–7, PB0–7, PC0–7, OSC1, IRQ,RESET,
TCAP1, TCAP2, RDI VIL VSS — 0.2VDD V
Supply current(3)
RUN (SM = 0) (See Figure 11-2)
RUN (SM = 1) (See Figure 11-3)
WAIT (SM = 0) (See Figure 11-4)
WAIT (SM = 1) (See Figure 11-5)
STOP 0 to 70 (standard)
– 40 to 85 (extended)
– 40 to 105 (extended)
– 40 to 125 (automotive)
IDD
IDD
IDD
IDD
IDD
IDD
IDD
IDD
—
—
—
—
—
—
—
—
3
1
1.5
0.5
10
10
40
40
TBD
TBD
TBD
TBD
TBD
TBD
TBD
TBD
mA
mA
mA
mA
A
A
A
A
High-Z leakage current
PA0–7, PB0–7, PC0–7, TDO, RESET, SCLK IIL — 0.2 1 A
Input current (0 to 70)
IRQ, OSC1, TCAP1, TCAP2, RDI,
PD0/AN0-PD7/AN7 (channel not selected) IIN — 0.2 1 A
Input current (– 40 to 125)
IRQ, OSC1, TCAP1, TCAP2, RDI,
PD0/AN0-PD7/AN7 (channel not selected) IIN — — 5 A
Capacitance
Ports (as input or output),RESET, TDO, SCLK
IRQ, TCAP1, TCAP2, OSC1, RDI
PD0/AN0–PD7/AN7 (A/D off)
PD0/AN0–PD7/AN7 (A/D on)
COUT
COUT
CIN
CIN
—
—
—
—
—
—
12
22
12
8
—
—
pF
pF
pF
pF
MOTOROLA
G-24 MC68HC05B6MC68HC705B32
14
G.2.7 A/D converter characteristics
G.2.8 Control timing
(1) Source impedances greater than 10k will adversely affect internal charging time during input sampling.
(2) The external system error caused by input leakage current is approximately equal to the product of R source and input
current. Input current to A/D channel will be dependent on external source impedance (see Figure 8-2).
Table G-10 A/D characteristics for 5V operation
(VDD = 5.0 Vdc  10%, VSS = 0 Vdc, TA = TL to TH)
Characteristic Parameter Min Max Unit
Resolution Number of bits resolved by the A/D 8 — Bit
Non-linearity Max deviation from the best straight line through the A/D
transfer characteristics
(VRH = VDD and VRL = 0V) —  0.5 LSB
Quantization error Uncertainty due to converter resolution —  0.5 LSB
Absolute accuracy Difference between the actual input voltage and the
full-scale equivalent of the binary code output code for all
errors —  1 LSB
Conversion range Analog input voltage range VRL VRH V
VRH Maximum analog reference voltage VRL VDD + 0.1 V
VRL Minimum analog reference voltage VSS – 0.1 VRH V
VRMinimum difference between VRH and VRL 3 — V
Conversion time Total time to perform a single analog to digital conversion
a. External clock (OSC1, OSC2)
b. Internal RC oscillator —
—32
32 tCYC
s
Monotonicity Conversion result never decreases with an increase in
input voltage and has no missing codes GUARANTEED
Zero input reading Conversion result when VIN = VRL 00 — Hex
Full scale reading Conversion result when VIN = VRH — FF Hex
Sample acquisition time Analog input acquisition sampling
a. External clock (OSC1, OSC2)
b. Internal RC oscillator(1) —
—12
12 tCYC
s
Sample/hold capacitance Input capacitance on PD0/AN0–PD7/AN7 — 12 pF
Input leakage(2) Input leakage on A/D pins PD0/AN0–PD7/AN7, VRL, VRH — 1 A
MC68HC05B6 MOTOROLA
G-25
MC68HC705B32
14
(1) Source impedances greater than 10k will adversely affect internal charging time during input sampling.
(2) The external system error caused by input leakage current is approximately equal to the product of R source and input
current. Input current to A/D channel will be dependent on external source impedance (see Figure 8-2).
Table G-11 A/D characteristics for 3.3V operation
(VDD = 3.3 Vdc  10%, VSS = 0 Vdc, TA = TL to TH)
Characteristic Parameter Min Max Unit
Resolution Number of bits resolved by the A/D 8 — Bit
Non-linearity Max deviation from the best straight line through the A/D
transfer characteristics
(VRH = VDD and VRL = 0V) —  1 LSB
Quantization error Uncertainty due to converter resolution —  1 LSB
Absolute accuracy Difference between the actual input voltage and the
full-scale equivalent of the binary code output code for all
errors —  2 LSB
Conversion range Analog input voltage range VRL VRH V
VRH Maximum analog reference voltage VRL VDD + 0.1 V
VRL Minimum analog reference voltage VSS – 0.1 VRH V
VRMinimum difference between VRH and VRL 3 — V
Conversion time Total time to perform a single analog to digital conversion
Internal RC oscillator — 32 s
Monotonicity Conversion result never decreases with an increase in
input voltage and has no missing codes GUARANTEED
Zero input reading Conversion result when VIN = VRL 00 — Hex
Full scale reading Conversion result when VIN = VRH — FF Hex
Sample acquisition time Analog input acquisition sampling
Internal RC oscillator(1) — 12 s
Sample/hold capacitance Input capacitance on PD0/AN0–PD7/AN7 — 12 pF
Input leakage(2) Input leakage on A/D pins PD0/AN0–PD7/AN7, VRL, VRH — 1 A
MOTOROLA
G-26 MC68HC05B6MC68HC705B32
14
(1) For bus frequencies less than 2 MHz, the internal RC oscillator should be used when
programming the EEPROM.
(2) Since a 2-bit prescaler in the timer must count four external cycles (tcyc), this is the limiting
factor in determining the timer resolution.
(3) The minimum period tTLTL should not be less than the number of cycle times it takes to
execute the capture interrupt service routine plus 24 tcyc.
(4) The minimum period tILIL should not be less than the number of cycle times it takes to
execute the interrupt service routine plus 21 tcyc.
Table G-12 Control timing for 5V operation
(VDD = 5.0 Vdc  10%, VSS = 0 Vdc, TA = TL to TH)
Characteristic Symbol Min Max Unit
Frequency of operation
Crystal option
External clock option fOSC
fOSC
—
dc 4.2
4.2 MHz
MHz
Internal operating frequency (fOSC/2)
Crystal
External clock fOP
fOP
—
dc 2.1
2.1 MHz
MHz
Cycle time (see Figure 9-1) tCYC 480 — ns
Crystal oscillator start-up time (see Figure 9-1) tOXOV — 100 ms
Stop recovery start-up time (crystal oscillator) tILCH 100 ms
External RESET input pulse width tRL 1.5 — tCYC
Power-on RESET output pulse width
4064 cycle
16 cycle tPORL
tPORL
4064
16 —
—
tCYC
tCYC
Watchdog RESET output pulse width tDOGL 1.5 — tCYC
Watchdog time-out tDOG 6144 7168 tCYC
EPROM programming time tPROG 5 15 ms
EEPROM byte erase time
0 to 70 (standard)
– 40 to 85 (extended)
– 40 to 105 (industrial)
– 40 to 125 (automotive)
tERA
tERA
tERA
tERA
10
10
10
10
—
—
—
—
ms
ms
ms
ms
EEPROM byte program time(1)
0 to 70 (standard)
– 40 to 85 (extended)
– 40 to 105 (industrial)
– 40 to 125 (automotive)
tPROG
tPROG
tPROG
tPROG
10
10
15
20
—
—
—
—
ms
ms
ms
ms
Timer (see Figure G-11)
Resolution(2)
Input capture pulse width
Input capture pulse period
tRESL
tTH, tTL
tTLTL
4
125
—(3)
—
—
—
tCYC
ns
tCYC
Interrupt pulse width (edge-triggered) tILIH 125 — ns
Interrupt pulse period tILIL —(4) — tCYC
OSC1 pulse width tOH, tOL 90 — ns
MC68HC05B6 MOTOROLA
G-27
MC68HC705B32
14
(1) For bus frequencies less than 2 MHz, the internal RC oscillator should be used when
programming the EEPROM.
(2) Since a 2-bit prescaler in the timer must count four external cycles (tcyc), this is the limiting
factor in determining the timer resolution.
(3) The minimum period tTLTL should not be less than the number of cycle times it takes to
execute the capture interrupt service routine plus 24 tcyc.
(4) The minimum period tILIL should not be less than the number of cycle times it takes to
execute the interrupt service routine plus 21 tcyc.
Table G-13 Control timing for operation at 3.3V
(VDD = 3.3Vdc  10%, VSS = 0 Vdc, TA = TL to TH)
Characteristic Symbol Min Max Unit
Frequency of operation
Crystal option
External clock option fOSC
fOSC
—
dc 2.0
2.0 MHz
MHz
Internal operating frequency (fOSC/2)
Crystal
External clock fOP
fOP
—
dc 1.0
1.0 MHz
MHz
Cycle time (see Figure 9-1) tCYC 1000 — ns
Crystal oscillator start-up time (see Figure 9-1) tOXOV — 100 ms
Stop recovery start-up time (crystal oscillator) tILCH 100 ms
External
RESET input pulse width tRL 1.5 — tCYC
Power-on RESET output pulse width
4064 cycle
16 cycle tPORL
tPORL
4064
16 —
—
tCYC
tCYC
Watchdog RESET output pulse width tDOGL 1.5 — tCYC
Watchdog time-out tDOG 6144 7168 tCYC
EEPROM byte erase time
0 to 70 (standard)
– 40 to 85 (extended)
– 40 to 105 (industrial)
– 40 to 125 (automotive)
tERA
tERA
tERA
tERA
30
30
30
30
—
—
—
—
ms
ms
ms
ms
EEPROM byte program time(1)
0 to 70 (standard)
– 40 to 85 (extended)
– 40 to 85 (industrial)
– 40 to 125 (automotive)
tPROG
tPROG
tPROG
tPROG
30
30
30
30
—
—
—
—
ms
ms
ms
ms
Timer (see Figure G-11)
Resolution(2)
Input capture pulse width
Input capture pulse period
tRESL
tTH, tTL
tTLTL
4
250
—(3)
—
—
—
tCYC
ns
tCYC
Interrupt pulse width (edge-triggered) tILIH 250 — ns
Interrupt pulse period tILIL —(4) — tCYC
OSC1 pulse width tOH, tOL 100 — ns
MOTOROLA
G-28 MC68HC05B6MC68HC705B32
14
Figure G-11 Timer relationship
External
signal
(TCAP1,
TCAP2)
tTLTL tTH tTL
MC68HC05B6 MOTOROLA
H-1
HIGH SPEED OPERATION
15
H
HIGH SPEED OPERATION
This section contains the electrical specifications and associated timing information for high speed
versions of the MC68HC05B6 and MC68HC05B8 (fOSC max = 8 MHz). The ordering information
for these devices is contained in Table H-1.
Note:
The high speed version has the same device title as the standard version. High speed
operation is selected via a check-box on the order form and will be confir med on the
listing verification form.
Table H-1 Ordering information
Device title Package Suffix
0 to 70C Suffix
-40 to +85C
MC68HC05B6 52-pin PLCC FN CFN
64-pin QFP FU CFU
56-pin SDIP B CB
MC68HC05B8 52-pin PLCC FN CFN
64-pin QFP FU CFU
56-pin SDIP B CB
MOTOROLA
H-2 MC68HC05B6HIGH SPEED OPERATION
15
H.1 DC electrical characteristics
(1) All IDD measurements taken with suitable decoupling capacitors across the po wer supply to suppress the transient
switching currents inherent in CMOS designs (see Section 2).
(2) Typical values are at mid point of voltage range and at 25C only.
(3) RUN and WAIT IDD: measured using an external square-wave clock source (fOSC = 8.0MHz); all inputs 0.2 V from
rail; no DC loads; maximum load on outputs 50pF (20pF on OSC2).
STOP /WAIT IDD: all ports configured as inputs; VIL = 0.2 V and VIH = VDD – 0.2 V: STOP IDD measured with
OSC1 = VDD.
WAIT IDD is affected linearly by the OSC2 capacitance.
Table H-2 DC electrical characteristics for 5V operation
(VDD = 5 Vdc  10%, VSS = 0 Vdc, TA = TL to TH)
Characteristic(1) Symbol Min Typ(2) Max Unit
Output voltage
ILOAD = – 10 A
ILOAD = +10 A VOH
VOL
VDD – 0.1
——
——
0.1 V
Output high voltage (ILOAD = 0.8mA)
PA0–7, PB0–7, PC0–7, TCMP1, TCMP2
Output high voltage (ILOAD = 1.6mA)
TDO, SCLK, PLMA, PLMB
VOH
VOH
VDD – 0.8
VDD – 0.8
—
—
—
—
—
V
Output low voltage (ILOAD = 1.6mA)
PA0–7, PB0–7, PC0–7, TCMP1, TCMP2,
TDO, SCLK, PLMA, PLMB
Output low voltage (ILOAD = 1.6mA)
RESET
VOL
VOL
—
—
—
—
—
—
0.4
1
V
Input high voltage
PA0–7, PB0–7, PC0–7, PD0–7, OSC1,
IRQ, RESET, TCAP1, TCAP2, RDI VIH 0.7VDD — VDD V
Input low voltage
PA0–7, PB0–7, PC0–7, OSC1, IRQ,RESET,
TCAP1, TCAP2, RDI VIL VSS — 0.2VDD V
Supply current(3)
RUN (SM = 0) (See Figure 11-2)
RUN (SM = 1) (See Figure 11-3)
WAIT (SM = 0) (See Figure 11-4)
WAIT (SM = 1) (See Figure 11-5)
STOP 0 to 70 (standard)
– 40 to 85 (extended)
IDD
—
—
—
—
—
—
—
—
—
—
—
—
12
3
4
2
10
20
mA
mA
mA
mA
A
A
High-Z leakage current
PA0–7, PB0–7, PC0–7, TDO, RESET, SCLK IIL — — 1 A
Input current (0 to 70)
IRQ, OSC1, TCAP1, TCAP2, RDI,
PD0/AN0-PD7/AN7 (channel not selected) IIN — —
—5
1 A
Capacitance
Ports (as input or output), RESET, TDO, SCLK
IRQ, TCAP1, TCAP2, OSC1, RDI
PD0/AN0–PD7/AN7 (A/D off)
PD0/AN0–PD7/AN7 (A/D on)
COUT
CIN
CIN
CIN
—
—
—
—
—
—
12
22
12
8
TBD
TBD
pF
pF
pF
pF
MC68HC05B6 MOTOROLA
H-3
HIGH SPEED OPERATION
15
H.2 A/D converter characteristics
(1) Performance verified down to 2.5V VR, but accuracy is tested and guaranteed at VR = 5V10%.
(2) Source impedances greater than 10k will adversely affect internal charging time during input sampling.
(3) The external system error caused by input leakage current is approximately equal to the product of R
source and input current. Input current to A/D channel will be dependent on external source impedance
(see Figure 8-2).
Table H-3 A/D characteristics for 5V operation
(VDD = 5.0 Vdc  10%, VSS = 0 Vdc, TA = TL to TH)
Characteristic Parameter Min Max Unit
Resolution Number of bits resolved by the A/D 8 — Bit
Non-linearity Max deviation from the best str aight line through
the A/D transfer characteristics
(VRH = VDD and VRL = 0V) —  0.5 LSB
Quantization error Uncertainty due to converter resolution —  0.5 LSB
Absolute accuracy Difference between the actual input v oltage and
the full-scale equivalent of the binary code
output code for all errors —  1 LSB
Conversion range Analog input voltage range VRL VRH V
VRH Maximum analog reference voltage VRL VDD + 0.1 V
VRL Minimum analog reference voltage VSS – 0.1 VRH V
VR(1) Minimum difference between VRH and VRL 3 — V
Conversion time
Total time to perform a single analog to digital
conversion
a. External clock (OSC1, OSC2)
b. Internal RC oscillator —
—32
32 tCYC
s
Monotonicity Conversion result never decreases with an
increase in input voltage and has no missing
codes GUARANTEED
Zero input reading Conversion result when VIN = VRL 00 — Hex
Full scale reading Conversion result when VIN = VRH — FF Hex
Sample acquisition
time
Analog input acquisition sampling
a. External clock (OSC1, OSC2)
b. Internal RC oscillator(2) —
—12
12 tCYC
s
Sample/hold
capacitance Input capacitance on PD0/AN0–PD7/AN7 — 12 pF
Input leakage(3) Input leakage on A/D pins PD0/AN0–PD7/AN7
VRL, VRH —
—1
1A
A
MOTOROLA
H-4 MC68HC05B6HIGH SPEED OPERATION
15
H.3 Control timing for 5V operation
(1) For bus frequencies less than 2 MHz, the internal RC oscillator should be used when
programming the EEPROM.
(2) Since a 2-bit prescaler in the timer must count four external cycles (tcyc), this is the limiting
factor in determining the timer resolution.
(3) The minimum period tTLTL should not be less than the number of cycle times it takes to
execute the capture interrupt service routine plus 24 tcyc.
(4) The minimum period tILIL should not be less than the number of cycle times it takes to
execute the interrupt service routine plus 21 tcyc.
(VDD = 5.0 Vdc  10%, VSS = 0 Vdc, TA = TL to TH)
Characteristic Symbol Min Max Unit
Frequency of operation
Crystal option
External clock option fOSC
fOSC
—
dc 8.0
8.0 MHz
MHz
Internal operating frequency (fOSC/2)
Crystal
External clock fOP
fOP
—
dc 4.0
4.0 MHz
MHz
Cycle time (see Figure 9-1) tCYC 250 — ns
Crystal oscillator start-up time (see Figure 9-1) tOXOV — 100 ms
Stop recovery start-up time (crystal oscillator) tILCH 100 ms
External RESET input pulse width tRL 1.5 — tCYC
Power-on RESET output pulse width
4064 cycle
16 cycle tPORL
tPORL
4064
16 —
—
tCYC
tCYC
Watchdog RESET output pulse width tDOGL 1.5 — tCYC
Watchdog time-out tDOG 6144 7168 tCYC
EEPROM byte erase time
0 to 70 (standard)
– 40 to 85 (extended) tERA
tERA
10
10 —
—ms
ms
EEPROM byte program time(1)
0 to 70 (standard)
– 40 to 85 (extended) tPROG
tPROG
10
10 —
—ms
ms
Timer (see Figure H-1)
Resolution(2)
Input capture pulse width
Input capture pulse period
tRESL
tTH, tTL
tTLTL
4
125
—(3)
—
—
—
tCYC
ns
tCYC
Interrupt pulse width (edge-triggered) tILIH 125 — ns
Interrupt pulse period tILIL —(4) — tCYC
OSC1 pulse width tOH, tOL 90 — ns
Figure H-1 Timer relationship
External
signal
(TCAP1,
TCAP2)
tTLTL tTH tTL
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Organisation Tables
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SECTION 1 INTRODUCTION
SECTION 2 MODES OF OPERATION AND PIN DESCRIPTIONS
SECTION 3 MEMORY AND REGISTERS
SECTION 4 INPUT/OUTPUT PORTS
SECTION 5 PROGRAMMABLE TIMER
SECTION 6 SERIAL COMMUNICATIONS INTERFACE
SECTION 7 PULSE LENGTH D/A CONVERTERS
SECTION 8 ANALOG TO DIGITAL CONVERTER
SECTION 9 RESETS AND INTERRUPTS
SECTION 10 CPU CORE AND INSTRUCTION SET
SECTION 11 ELECTRICAL SPECIFICATIONS
SECTION 12 MECHANICAL DATA
SECTION 13 ORDERING INFORMATION
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MOTOROLA LTD.
Semiconductor Products Sector
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INTRODUCTION
MODES OF OPERATION AND PIN DESCRIPTIONS
MEMORY AND REGISTERS
INPUT/OUTPUT PORTS
PROGRAMMABLE TIMER
SERIAL COMMUNICATIONS INTERFACE
PULSE LENGTH D/A CONVERTERS
ANALOG TO DIGITAL CONVERTER
RESETS AND INTERRUPTS
CPU CORE AND INSTRUCTION SET
ELECTRICAL SPECIFICATIONS
MECHANICAL DATA
ORDERING INFORMATION
APPENDICES
HIGH SPEED OPERATION
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INTRODUCTION
MODES OF OPERATION AND PIN DESCRIPTIONS
MEMORY AND REGISTERS
INPUT/OUTPUT PORTS
PROGRAMMABLE TIMER
SERIAL COMMUNICATIONS INTERFACE
PULSE LENGTH D/A CONVERTERS
ANALOG TO DIGITAL CONVERTER
RESETS AND INTERRUPTS
CPU CORE AND INSTRUCTION SET
ELECTRICAL SPECIFICATIONS
MECHANICAL DATA
ORDERING INFORMATION
APPENDICES
HIGH SPEED OPERATION
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Literature Distribution Centres:
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JAPAN: Nippon Motorola Ltd., 4-32-1, Nishi-Gotanda, Shinagawa-ku, Tokyo 141, Japan.
USA: Motorola Literature Distribution, P.O. Box 20912, Phoenix, Arizona 85036.
!MOTOROLA MC68HC05B6/D