MOTOROLA MC68HC11PH8

MC68HC11PH8/D
MC68HC11PH8
HC11
TECHNICAL DATA
MC68HC11PH8
MC68HC711PH8
TECHNICAL
DATA
!MOTOROLA
!MOTOROLA
INTRODUCTION
1
PIN DESCRIPTIONS
2
OPERATING MODES AND ON-CHIP MEMORY
3
PARALLEL INPUT/OUTPUT
4
SERIAL COMMUNICATIONS INTERFACE
5
MOTOROLA INTERCONNECT BUS (MI BUS)
6
SERIAL PERIPHERAL INTERFACE
7
TIMING SYSTEM
8
ANALOG-TO-DIGITAL CONVERTER
9
RESETS AND INTERRUPTS
10
CPU CORE AND INSTRUCTION SET
11
ELECTRICAL SPECIFICATIONS (STANDARD)
A
MECHANICAL DATA AND ORDERING INFORMATION
B
DEVELOPMENT SUPPORT
C
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1
1
INTRODUCTION
2
PIN DESCRIPTIONS
3
OPERATING MODES AND ON-CHIP MEMORY
4
PARALLEL INPUT/OUTPUT
5
SERIAL COMMUNICATIONS INTERFACE
6
MOTOROLA INTERCONNECT BUS (MI BUS)
7
SERIAL PERIPHERAL INTERFACE
8
TIMING SYSTEM
9
ANALOG-TO-DIGITAL CONVERTER
10
RESETS AND INTERRUPTS
11
CPU CORE AND INSTRUCTION SET
A
ELECTRICAL SPECIFICATIONS (STANDARD)
B
MECHANICAL DATA AND ORDERING INFORMATION
C
DEVELOPMENT SUPPORT
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1
MC68HC11PH8
MC68HC711PH8
2
3
High-density Complementary
Metal Oxide Semiconductor
(HCMOS) Microcomputer Unit
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All Trade Marks recognized. This document contains information on new products. Specifications and information herein are
subject to change without notice.
8
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.
9
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.
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© MOTOROLA LTD., 1997
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Conventions
Abbreviations
Definitions of any abbreviations used can be found in the Glossary.
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Text in italics
This document contains information referring to the MC68HC11PH8 and the
MC68HC711PH8. All references to the MC68HC11PH8 apply equally to the
MC68HC711PH8, unless otherwise noted. References specific to the
MC68HC711PH8 are italicised in the text.
Register tables
Because the bits in any one register are not necessarily linked by a common
function, the description of a register may appear in several sections referring to
different aspects of device operation. A full description of a bit is given only in a
section in which it has relevance. Elsewhere, it appears shaded in the register
diagram and is only briefly described.
State on reset
10
x
u
state of bit on reset depends on factors such as operating mode
state of bit on reset is undefined
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SECTION 1
INTRODUCTION
SECTION 2
PIN DESCRIPTIONS
SECTION 3
OPERATING MODES AND ON-CHIP MEMORY
SECTION 4
PARALLEL INPUT/OUTPUT
SECTION 5
SERIAL COMMUNICATIONS INTERFACE
SECTION 6
MOTOROLA INTERCONNECT BUS (MI BUS)
SECTION 7
SERIAL PERIPHERAL INTERFACE
SECTION 8
TIMING SYSTEM
SECTION 9
ANALOG-TO-DIGITAL CONVERTER
SECTION 10
RESETS AND INTERRUPTS
SECTION 11
CPU CORE AND INSTRUCTION SET
APPENDIX A
ELECTRICAL SPECIFICATIONS (STANDARD)
APPENDIX B
MECHANICAL DATA AND ORDERING INFORMATION
APPENDIX C
DEVELOPMENT SUPPORT
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TABLE OF CONTENTS
Paragraph
Number
Title
Page
Number
1
INTRODUCTION
1.1
1.2
Features.................................................................................................................1-1
Mask options .........................................................................................................1-2
2
PIN DESCRIPTIONS
2.1
VDD and VSS ........................................................................................................2-2
2.2
RESET...................................................................................................................2-3
2.3
Crystal driver and external clock input (XTAL, EXTAL)..........................................2-3
2.4
E clock output (E) ..................................................................................................2-5
2.5
Phase-locked loop (XFC, VDDSYN, 4XOUT) ........................................................2-6
2.5.1
PLL operation...................................................................................................2-7
2.5.2
Synchronization of PLL with subsystems.........................................................2-8
2.5.3
Changing the PLL frequency ...........................................................................2-8
2.5.4
PLL registers....................................................................................................2-8
2.5.4.1
PLLCR — PLL control register ...................................................................2-9
2.5.4.2
SYNR — Synthesizer program register......................................................2-11
2.6
Interrupt request (IRQ) ..........................................................................................2-12
2.7
Nonmaskable interrupt (XIRQ/VPPE)....................................................................2-12
2.8
MODA and MODB (MODA/LIR and MODB/VSTBY) .............................................2-13
2.9
VRH and VRL ........................................................................................................2-13
2.10 PG7/R/W ...............................................................................................................2-13
2.11 Port signals ............................................................................................................2-14
2.11.1
Port A ...............................................................................................................2-14
2.11.2
Port B ...............................................................................................................2-14
2.11.3
Port C ...............................................................................................................2-16
2.11.4
Port D ...............................................................................................................2-16
2.11.5
Port E ...............................................................................................................2-17
2.11.6
Port F ...............................................................................................................2-17
2.11.7
Port G...............................................................................................................2-17
2.11.8
Port H ...............................................................................................................2-18
2.12 LCD module...........................................................................................................2-18
2.12.1
LCDR — LCD control and data register...........................................................2-18
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Paragraph
Number
Title
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Number
3
OPERATING MODES AND ON-CHIP MEMORY
3.1
Operating modes ...................................................................................................3-1
3.1.1
Single chip operating mode .............................................................................3-1
3.1.2
Expanded operating mode...............................................................................3-1
3.1.3
Special test -mode ...........................................................................................3-2
3.1.4
Special bootstrap mode ...................................................................................3-2
3.2
On-chip memory....................................................................................................3-3
3.2.1
Mapping allocations .........................................................................................3-4
3.2.1.1
RAM ...........................................................................................................3-4
3.2.1.2
ROM and EPROM......................................................................................3-5
3.2.1.3
Bootloader ROM ........................................................................................3-5
3.2.2
Registers..........................................................................................................3-5
3.3
System initialization ...............................................................................................3-10
3.3.1
Mode selection.................................................................................................3-10
3.3.1.1
HPRIO — Highest priority I-bit interrupt & misc. register ...........................3-11
3.3.2
Initialization ......................................................................................................3-12
3.3.2.1
CONFIG — System configuration register .................................................3-12
3.3.2.2
INIT — RAM and I/O mapping register ......................................................3-14
3.3.2.3
INIT2 — EEPROM mapping and MI BUS delay register............................3-16
3.3.2.4
OPTION — System configuration options register 1..................................3-17
3.3.2.5
OPT2 — System configuration options register 2 ......................................3-18
3.3.2.6
BPROT — Block protect register................................................................3-21
3.3.2.7
TMSK2 — Timer interrupt mask register 2.................................................3-22
3.4
EPROM, EEPROM and CONFIG register .............................................................3-23
3.4.1
EPROM ............................................................................................................3-23
3.4.1.1
EPROG — EPROM programming control register.....................................3-23
3.4.1.2
EPROM programming ................................................................................3-24
3.4.2
EEPROM .........................................................................................................3-25
3.4.2.1
PPROG — EEPROM programming control register ..................................3-25
3.4.2.2
EEPROM bulk erase ..................................................................................3-27
3.4.2.3
EEPROM row erase ...................................................................................3-28
3.4.2.4
EEPROM byte erase ..................................................................................3-28
3.4.3
CONFIG register programming........................................................................3-29
3.4.4
RAM and EEPROM security............................................................................3-30
4
PARALLEL INPUT/OUTPUT
4.1
Port A.....................................................................................................................4-2
4.1.1
PORTA — Port A data register ........................................................................4-2
4.1.2
DDRA — Data direction register for port A .....................................................4-2
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Paragraph
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Title
Page
Number
4.2
Port B.....................................................................................................................4-3
4.2.1
PORTB — Port B data register ........................................................................4-3
4.2.2
DDRB — Data direction register for port B ......................................................4-3
4.3
Port C.....................................................................................................................4-4
4.3.1
PORTC — Port C data register........................................................................4-4
4.3.2
DDRC — Data direction register for port C......................................................4-4
4.4
Port D.....................................................................................................................4-5
4.4.1
PORTD — Port D data register........................................................................4-5
4.4.2
DDRD — Data direction register for port D......................................................4-5
4.5
Port E.....................................................................................................................4-6
4.5.1
PORTE — Port E data register ........................................................................4-6
4.6
Port F .....................................................................................................................4-7
4.6.1
PORTF — Port F data register.........................................................................4-7
4.6.2
DDRF — Data direction register for port F.......................................................4-7
4.7
Port G ....................................................................................................................4-8
4.7.1
PORTG — Port G data register .......................................................................4-8
4.7.2
DDRG — Data direction register for port G .....................................................4-8
4.8
Port H.....................................................................................................................4-9
4.8.1
PORTH — Port H data register........................................................................4-9
4.8.2
DDRH — Data direction register for port H......................................................4-9
4.8.3
Wired-OR interrupt...........................................................................................4-10
4.8.3.1
WOIEH — WOI enable (WOIEH) ...............................................................4-10
4.9
Internal pull-up resistors ........................................................................................4-11
4.9.1
PPAR — Port pull-up assignment register .......................................................4-11
4.10 System configuration .............................................................................................4-11
4.10.1
OPT2 — System configuration options register 2............................................4-12
4.10.2
CONFIG — System configuration register .......................................................4-13
5
SERIAL COMMUNICATIONS INTERFACE
5.1
5.2
5.3
5.4
5.4.1
5.4.2
5.5
5.6
5.6.1
5.6.2
5.6.3
5.6.4
5.6.5
5.6.6
Data format ............................................................................................................5-2
Transmit operation .................................................................................................5-2
Receive operation..................................................................................................5-2
Wake-up feature ....................................................................................................5-4
Idle-line wake-up ..............................................................................................5-4
Address-mark wake-up ....................................................................................5-4
SCI error detection ................................................................................................5-5
SCI registers ..........................................................................................................5-5
SCBDH, SCBDL — SCI baud rate control registers ........................................5-6
SCCR1 — SCI control register 1 .....................................................................5-7
SCCR2 — SCI control register 2 .....................................................................5-9
SCSR1 — SCI status register 1.......................................................................5-10
SCSR2 — SCI status register 2.......................................................................5-12
SCDRH, SCDRL — SCI data high/low registers .............................................5-12
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Paragraph
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Title
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Number
5.7
Status flags and interrupts.....................................................................................5-13
5.7.1
Receiver flags ..................................................................................................5-13
5.8
SCI2 ......................................................................................................................5-15
5.8.1
S2BDH, S2BDL — SCI2 baud rate control registers .......................................5-15
5.8.2
S2CR1 — SCI2 control register 1....................................................................5-16
5.8.3
S2CR2 — SCI2 control register 2....................................................................5-16
5.8.4
S2SR1 — SCI2 status register 1 .....................................................................5-16
5.8.5
S2SR2 — SCI2 status register 2 .....................................................................5-17
5.8.6
S2DRH, S2DRL — SCI2 data high/low registers ............................................5-17
6
MOTOROLA INTERCONNECT BUS (MI BUS)
6.1
6.1.1
6.1.2
6.2
6.3
6.3.1
6.3.2
6.4
6.5
6.6
6.6.1
6.6.2
6.6.3
6.6.4
6.6.5
6.6.6
6.6.7
Push-pull sequence ...............................................................................................6-2
The push field ..................................................................................................6-2
The pull field ....................................................................................................6-3
Biphase coding ......................................................................................................6-3
Message validation................................................................................................6-4
Controller detected errors ................................................................................6-4
MCU detected errors .......................................................................................6-4
Interfacing to MI BUS ............................................................................................6-6
MI BUS clock rate..................................................................................................6-7
SCI2/MI BUS registers ..........................................................................................6-7
INIT2 — EEPROM mapping and MI BUS delay register .................................6-8
S2BDH, S2BDL — MI BUS clock rate control registers...................................6-9
S2CR1 — MI BUS control register 1 ...............................................................6-9
S2CR2 — MI BUS control register 2 ...............................................................6-10
S2SR1 — MI BUS status register 1 .................................................................6-11
S2SR2 — MI BUS2 status register 2...............................................................6-12
S2DRL — MI BUS2 data register ....................................................................6-12
7
SERIAL PERIPHERAL INTERFACE
7.1
7.2
7.2.1
7.3
7.3.1
7.3.2
7.3.3
7.3.4
7.4
Functional description ...........................................................................................7-1
SPI transfer formats...............................................................................................7-2
Clock phase and polarity controls....................................................................7-3
SPI signals ............................................................................................................7-3
Master in slave out...........................................................................................7-4
Master out slave in...........................................................................................7-4
Serial clock ......................................................................................................7-4
Slave select......................................................................................................7-4
SPI system errors ..................................................................................................7-5
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Paragraph
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Number
7.5
SPI registers ..........................................................................................................7-5
7.5.1
SPCR — SPI control register...........................................................................7-6
7.5.2
SPSR — SPI status register ............................................................................7-7
7.5.3
SPDR — SPI data register...............................................................................7-8
7.5.4
OPT2 — System configuration options register 2............................................7-9
7.6
SPI2 .......................................................................................................................7-10
7.6.1
SP2CR — SPI2 control register.......................................................................7-11
7.6.2
SP2SR — SPI2 status register ........................................................................7-11
7.6.3
SP2DR — SPI2 data register...........................................................................7-11
7.6.4
SP2OPT — SPI2 control options register ........................................................7-11
8
TIMING SYSTEM
8.1
16-bit timer.............................................................................................................8-1
8.1.1
Timer enable control ........................................................................................8-3
8.1.1.1
PLLCR — PLL control register ...................................................................8-3
8.1.2
Timer structure.................................................................................................8-4
8.1.3
Input capture ....................................................................................................8-8
8.1.3.1
TCTL2 — Timer control register 2 ..............................................................8-9
8.1.3.2
TIC1–TIC3 — Timer input capture registers...............................................8-10
8.1.3.3
TI4/O5 — Timer input capture 4/output compare 5 register .......................8-10
8.1.4
Output compare ...............................................................................................8-11
8.1.4.1
TOC1–TOC4 — Timer output compare registers .......................................8-12
8.1.4.2
CFORC — Timer compare force register ...................................................8-12
8.1.4.3
OC1M — Output compare 1 mask register ................................................8-13
8.1.4.4
OC1D — Output compare 1 data register ..................................................8-13
8.1.4.5
TCNT — Timer counter register .................................................................8-14
8.1.4.6
TCTL1 — Timer control register 1 ..............................................................8-14
8.1.4.7
TMSK1 — Timer interrupt mask register 1 .................................................8-15
8.1.4.8
TFLG1 — Timer interrupt flag register 1 ....................................................8-16
8.1.4.9
TMSK2 — Timer interrupt mask register 2 .................................................8-17
8.1.4.10
TFLG2 — Timer interrupt flag register 2 ....................................................8-18
8.1.5
Real-time interrupt ...........................................................................................8-19
8.1.5.1
TMSK2 — Timer interrupt mask register 2 .................................................8-20
8.1.5.2
TFLG2 — Timer interrupt flag register 2 ....................................................8-21
8.1.5.3
PACTL — Pulse accumulator control register ............................................8-22
8.1.6
Computer operating properly watchdog function .............................................8-23
8.1.7
LCD module .....................................................................................................8-23
8.1.8
Pulse accumulator ...........................................................................................8-23
8.1.8.1
PACTL — Pulse accumulator control register ............................................8-25
8.1.8.2
PACNT — Pulse accumulator count register..............................................8-26
8.1.8.3
Pulse accumulator status and interrupt bits ...............................................8-26
8.1.8.4
TMSK2 — Timer interrupt mask 2 register .................................................8-26
8.1.8.5
TFLG2 — Timer interrupt flag 2 register ....................................................8-26
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8.2
Pulse-width modulation (PWM) timer ....................................................................8-27
8.2.1
PWM timer block diagram................................................................................8-28
8.2.2
PWCLK — PWM clock prescaler and 16-bit select register ............................8-28
8.2.2.1
16-bit PWM function...................................................................................8-28
8.2.2.2
Clock prescaler selection ...........................................................................8-30
8.2.3
PWPOL — PWM timer polarity & clock source select register ........................8-31
8.2.4
PWSCAL — PWM timer prescaler register .....................................................8-31
8.2.5
PWEN — PWM timer enable register ..............................................................8-32
8.2.6
PWCNT1–4 — PWM timer counter registers 1 to 4 ........................................8-33
8.2.7
PWPER1–4 — PWM timer period registers 1 to 4 ..........................................8-33
8.2.8
PWDTY1–4 — PWM timer duty cycle registers 1 to 4.....................................8-34
8.2.9
Boundary cases ...............................................................................................8-34
8.3
8-bit modulus timers ..............................................................................................8-35
8.3.1
Modulus timer operation ..................................................................................8-35
8.3.2
Clock rate selection..........................................................................................8-37
8.3.2.1
T8ADR — 8-bit modulus timer A data register...........................................8-38
8.3.2.2
T8ACR — 8-bit modulus timer A control register .......................................8-38
8.3.2.3
T8BDR — 8-bit modulus timer B data register...........................................8-39
8.3.2.4
T8BCR — 8-bit modulus timer B control register .......................................8-39
8.3.2.5
T8CDR — 8-bit modulus timer C data register ..........................................8-40
8.3.2.6
T8CCR — 8-bit modulus timer C control register.......................................8-40
9
ANALOG-TO-DIGITAL CONVERTER
9.1
9.1.1
9.1.2
9.1.3
9.1.4
9.1.5
9.1.6
9.1.7
9.2
9.2.1
9.3
9.3.1
9.3.2
9.4
9.4.1
9.4.2
9.5
Overview................................................................................................................9-1
Multiplexer........................................................................................................9-2
Analog converter..............................................................................................9-3
Digital control ...................................................................................................9-3
Result registers................................................................................................9-4
A/D converter clocks ........................................................................................9-4
Conversion sequence ......................................................................................9-4
Conversion process .........................................................................................9-5
A/D converter power-up and clock select ..............................................................9-5
OPTION — System configuration options register 1 .......................................9-5
Channel assignments ............................................................................................9-7
Single-channel operation .................................................................................9-7
Multiple-channel operation...............................................................................9-8
Control, status and results registers ......................................................................9-8
ADCTL — A/D control and status register .......................................................9-8
ADR1–ADR4 — A/D converter results registers..............................................9-10
Operation in STOP and WAIT modes....................................................................9-10
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10
RESETS AND INTERRUPTS
10.1 Resets .................................................................................................................10-1
10.1.1
Power-on reset ...............................................................................................10-1
10.1.2
External reset (RESET) .................................................................................10-2
10.1.3
COP reset ......................................................................................................10-2
10.1.3.1
COPRST — Arm/reset COP timer circuitry register.................................10-3
10.1.4
Clock monitor reset ........................................................................................10-4
10.1.5
OPTION — System configuration options register 1 .....................................10-4
10.1.6
CONFIG — Configuration control register ....................................................10-6
10.2 Effects of reset.....................................................................................................10-7
10.2.1
Central processing unit ..................................................................................10-8
10.2.2
Memory map ..................................................................................................10-8
10.2.3
Parallel I/O .....................................................................................................10-8
10.2.4
Timer..............................................................................................................10-8
10.2.5
Real-time interrupt (RTI) ................................................................................10-9
10.2.6
Pulse accumulator .........................................................................................10-9
10.2.7
Computer operating properly (COP) ..............................................................10-9
10.2.8
8-bit modulus timer system ............................................................................10-9
10.2.9
Serial communications interface (SCI)...........................................................10-9
10.2.10 Serial peripheral interface (SPI) .....................................................................10-10
10.2.11 Analog-to-digital converter .............................................................................10-10
10.2.12 LCD module ...................................................................................................10-10
10.2.13 System ...........................................................................................................10-10
10.3 Reset and interrupt priority ..................................................................................10-11
10.3.1
HPRIO — Highest priority I-bit interrupt and misc. register ...........................10-12
10.4 Interrupts .............................................................................................................10-15
10.4.1
Interrupt recognition and register stacking.....................................................10-15
10.4.2
Nonmaskable interrupt request (XIRQ)..........................................................10-16
10.4.3
Illegal opcode trap..........................................................................................10-16
10.4.4
Software interrupt...........................................................................................10-16
10.4.5
Maskable interrupts........................................................................................10-17
10.4.6
Reset and interrupt processing ......................................................................10-17
10.5 Low power operation ...........................................................................................10-17
10.5.1
WAIT ..............................................................................................................10-17
10.5.2
STOP .............................................................................................................10-18
11
CPU CORE AND INSTRUCTION SET
11.1 Registers .............................................................................................................11-1
11.1.1
Accumulators A, B and D...............................................................................11-2
11.1.2
Index register X (IX) .......................................................................................11-2
11.1.3
Index register Y (IY) .......................................................................................11-2
TPG
MC68HC11PH8
TABLE OF CONTENTS
MOTOROLA
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13
Paragraph
Number
Title
Page
Number
11.1.4
Stack pointer (SP)..........................................................................................11-2
11.1.5
Program counter (PC)....................................................................................11-4
11.1.6
Condition code register (CCR).......................................................................11-4
11.1.6.1
Carry/borrow (C) ......................................................................................11-5
11.1.6.2
Overflow (V) .............................................................................................11-5
11.1.6.3
Zero (Z) ....................................................................................................11-5
11.1.6.4
Negative (N) .............................................................................................11-5
11.1.6.5
Interrupt mask (I)......................................................................................11-5
11.1.6.6
Half carry (H)............................................................................................11-6
11.1.6.7
X interrupt mask (X) .................................................................................11-6
11.1.6.8
Stop disable (S)........................................................................................11-6
11.2 Data types ...........................................................................................................11-6
11.3 Opcodes and operands .......................................................................................11-7
11.4 Addressing modes...............................................................................................11-7
11.4.1
Immediate (IMM)............................................................................................11-7
11.4.2
Direct (DIR)....................................................................................................11-7
11.4.3
Extended (EXT) .............................................................................................11-8
11.4.4
Indexed (IND, X; IND, Y).................................................................................11-8
11.4.5
Inherent (INH) ................................................................................................11-8
11.4.6
Relative (REL)................................................................................................11-8
11.5 Instruction set ......................................................................................................11-8
A
ELECTRICAL SPECIFICATIONS (STANDARD)
A.1
A.2
A.3
A.4
A.4.1
A.5
A.5.1
A.5.2
A.5.3
A.5.4
A.5.5
A.5.6
A.5.7
Maximum ratings .................................................................................................. A-1
Thermal characteristics and power considerations .............................................. A-2
Test methods ........................................................................................................ A-3
DC electrical characteristics ................................................................................. A-4
DC electrical characteristics — modes of operation ....................................... A-5
Control timing ....................................................................................................... A-6
Peripheral port timing...................................................................................... A-9
PLL control timing ........................................................................................... A-10
Analog-to-digital converter characteristics...................................................... A-11
Serial peripheral interface timing .................................................................... A-12
Non-multiplexed expansion bus timing ........................................................... A-15
EEPROM characteristics ................................................................................ A-16
EPROM characteristics .................................................................................. A-16
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MOTOROLA
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TABLE OF CONTENTS
MC68HC11PH8
14
Paragraph
Number
Title
Page
Number
B
MECHANICAL DATA AND ORDERING INFORMATION
B.1
B.2
B.3
Pin assignments ................................................................................................... B-1
Package dimensions............................................................................................. B-3
Ordering Information............................................................................................. B-6
C
DEVELOPMENT SUPPORT
C.1
C.2
C.3
EVS — Evaluation system.................................................................................... C-1
MMDS11 — Motorola modular development system ........................................... C-2
SPGMR11 — Serial programmer system............................................................. C-2
GLOSSARY
INDEX
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MC68HC11PH8
TABLE OF CONTENTS
MOTOROLA
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TABLE OF CONTENTS
MC68HC11PH8
16
LIST OF FIGURES
Figure
Number
1-1
2-1
2-2
2-3
2-4
2-5
2-6
2-7
3-1
3-2
3-3
5-1
5-2
5-3
6-1
6-2
6-3
6-4
7-1
7-2
8-1
8-2
8-3
8-4
8-5
8-6
8-7
9-1
9-2
9-3
10-1
10-2
10-3
Title
Page
Number
MC68HC11PH8/MC68HC711PH8 block diagram ..................................................1-3
84-pin PLCC/CERQUAD pinout .............................................................................2-1
112-pin TQFP pinout ..............................................................................................2-2
External reset circuitry............................................................................................2-3
Oscillator connections (VDDSYN = 0, PLL disabled) .............................................2-4
Oscillator connections (VDDSYN = 1, PLL enabled)..............................................2-5
PLL circuit...............................................................................................................2-6
RAM stand-by connections.....................................................................................2-13
MC68HC11PH8/MC68HC711PH8 memory map ...................................................3-3
Example of expanded mode FREEZ actions..........................................................3-13
RAM and register overlap.......................................................................................3-15
SCI baud rate generator circuit diagram.................................................................5-1
SCI1 block diagram ................................................................................................5-3
Interrupt source resolution within SCI.....................................................................5-14
MI BUS timing.........................................................................................................6-2
Biphase coding and error detection........................................................................6-3
MI BUS block diagram ............................................................................................6-5
A typical interface between the MC68HC11PH8 and the MI BUS..........................6-6
SPI block diagram...................................................................................................7-2
SPI transfer format..................................................................................................7-3
Timer clock divider chains (PLL enabled — VDDSYN high) ..................................8-5
Timer clock divider chains (PLL disabled — VDDSYN low) ...................................8-6
Capture/compare block diagram.............................................................................8-7
Pulse accumulator block diagram...........................................................................8-24
PWM timer block diagram.......................................................................................8-29
PWM duty cycle......................................................................................................8-34
8-bit modulus timer system.....................................................................................8-36
A/D converter block diagram ..................................................................................9-2
Electrical model of an A/D input pin (in sample mode)...........................................9-3
A/D conversion sequence.......................................................................................9-4
Processing flow out of reset (1 of 2) .....................................................................10-19
Processing flow out of reset (2 of 2) .....................................................................10-20
Interrupt priority resolution (1 of 3) .......................................................................10-21
TPG
MC68HC11PH8
LIST OF FIGURES
MOTOROLA
xi
17
Figure
Number
10-4
10-5
10-6
10-7
11-1
11-2
A-1
A-2
A-3
A-4
A-5
A-6
A-7
A-8
A-9
A-10
A-11
A-12
A-13
B-1
B-2
B-3
B-4
B-5
Title
Page
Number
Interrupt priority resolution (2 of 3) ....................................................................... 10-22
Interrupt priority resolution (3 of 3) ....................................................................... 10-23
Interrupt source resolution within the SCI subsystem .......................................... 10-24
Interrupt source resolution within the 8-bit modulus timer subsystem.................. 10-25
Programming model ............................................................................................. 11-1
Stacking operations .............................................................................................. 11-3
Test methods ..........................................................................................................A-3
Timer inputs............................................................................................................A-6
Reset timing ...........................................................................................................A-7
Interrupt timing .......................................................................................................A-7
STOP recovery timing ............................................................................................A-8
WAIT recovery timing .............................................................................................A-8
Port read timing diagram ........................................................................................A-9
Port write timing diagram........................................................................................A-9
SPI master timing (CPHA = 0) ...............................................................................A-13
SPI master timing (CPHA = 1) ...............................................................................A-13
SPI slave timing (CPHA = 0) ..................................................................................A-14
SPI slave timing (CPHA = 1) ..................................................................................A-14
Expansion bus timing .............................................................................................A-16
84-pin PLCC/CERQUAD pinout .............................................................................B-1
112-pin TQFP pinout ..............................................................................................B-2
84-pin PLCC mechanical dimensions ....................................................................B-3
84-pin CERQUAD mechanical dimensions ............................................................B-4
112-pin TQFP mechanical dimensions...................................................................B-5
TPG
MOTOROLA
xii
LIST OF FIGURES
MC68HC11PH8
18
LIST OF TABLES
Table
Number
2-1
2-2
3-1
3-2
3-3
3-4
3-5
3-6
3-7
3-8
4-1
5-1
7-1
8-1
8-2
8-3
8-4
8-5
8-6
9-1
10-1
10-2
10-3
10-4
10-5
10-6
11-1
11-2
B-1
C-1
Title
Page
Number
PLL mask options ...................................................................................................2-7
Port signal functions ...............................................................................................2-15
Example bootloader baud rates..............................................................................3-3
Register and control bit assignments .....................................................................3-6
Registers with limited write access.........................................................................3-10
Hardware mode select summary............................................................................3-11
RAM and register remapping..................................................................................3-15
EEPROM remapping ..............................................................................................3-16
EEPROM block protect...........................................................................................3-21
Erase mode selection .............................................................................................3-26
Port configuration ...................................................................................................4-1
Example SCI baud rate control values ...................................................................5-7
SPI clock rates........................................................................................................7-7
Timer resolution and capacity.................................................................................8-2
RTI periodic rates (PLL disabled) ...........................................................................8-19
RTI periodic rates (PLL enabled)............................................................................8-19
Pulse accumulator timing .......................................................................................8-23
Clock A and clock B prescalers ..............................................................................8-30
Modulus timers clock sources ................................................................................8-37
A/D converter channel assignments.......................................................................9-7
COP timer rate select (PLL disabled) ...................................................................10-3
COP timer rate select (PLL enabled)....................................................................10-3
Reset cause, reset vector and operating mode ....................................................10-7
Highest priority interrupt selection ........................................................................10-13
Interrupt and reset vector assignments ................................................................10-14
Stacking order on entry to interrupts ....................................................................10-15
Reset vector comparison......................................................................................11-4
Instruction set .......................................................................................................11-9
Ordering information.............................................................................................. B-6
M68HC11 development tools ................................................................................ C-1
TPG
MC68HC11PH8
LIST OF TABLES
MOTOROLA
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LIST OF TABLES
MC68HC11PH8
20
1
1
INTRODUCTION
The MC68HC11PH8 8-bit microcontroller is a member of the M68HC11 family of HCMOS
microcontrollers. In addition to 48K bytes of ROM, the MC68HC11PH8 contains 2K bytes of RAM
and 768 bytes of EEPROM. Making use of an 84-pin PLCC, or 112-pin TQFP package, a
non-multiplexed expanded bus is a feature of this device. The timer system has been expanded to
include three input captures, four output compares and a software selectable input capture or
output compare. There are three 8-bit modulus timers, one of which may be used as a prescaler
for the other two. The inclusion of a PLL circuit allows power consumption and performance to be
adjusted to suit operational requirements. Other major features of this device are: 8-channel, 8-bit
A/D converter, four PWM timer channels, wired-OR capability for keyboard interrupt, four LCD
segment drivers and two SPI and two enhanced SCI subsystems. The MC68HC11PH8 is
especially suitable for mobile communications and automotive applications.
The MC68HC711PH8 is an EPROM version of the MC68HC11PH8, with the user ROM replaced
by a similar amount of EPROM. All references to the MC68HC11PH8 apply equally to the
MC68HC711PH8, unless otherwise noted. References specific to the MC68HC711PH8 are
italicised in the text.
1.1
Features
•
Low power, high performance M68HC11 CPU core
•
48K bytes of user ROM (MC68HC11PH8); 48K bytes of user EPROM (MC68HC711PH8)
•
2K bytes of RAM
•
768 bytes of byte-erasable user EEPROM, with on-chip charge pump
•
Up to 54 general purpose I/O lines, plus up to 8 input-only lines
•
Non-multiplexed address and data buses, permitting direct access to the full 64K address map
•
16-bit timer with 3/4 input captures and 4/5 output compares; pulse accumulator and COP
watchdog timer
•
Three 8-bit modulus timers, for generating periodic interrupts
TPG
MC68HC11PH8
INTRODUCTION
MOTOROLA
1-1
21
1
•
Power saving PLL circuit
•
Wired-OR interrupt capability for keyboard support, allowing wake-up from STOP and WAIT
modes
•
Two 8- or 9-bit SCI subsystems, one with MI BUS† capability; both NRZ type for RS232
compatibility
•
Two SPI subsystems, with software selectable MSB/LSB first option
•
8-channel, 8-bit analog-to-digital (A/D) converter
•
Four 8-bit PWM timer channels (may be concatenated to form one or two 16-bit channels)
•
4-segment LCD driver
•
Available in 84-pin PLCC or 112-pin TQFP packages (MC68HC11PH8); also 84-pin
CERQUAD package (MC68HC711PH8)
1.2
Mask options
There are five mask options available on the MC68HC11PH8. These options are programmed
during manufacture and must be specified on the order form.
•
Security option (available/unavailable); see Section 3.4.4
•
PLL oscillator frequency (32kHz/614kHz); see Section 2.5
•
Oscillator buffer type (inverter/Schmitt trigger); see Section 2.3
•
POR/exit from STOP start-up time (4064/128 bus cycles); see Section 3.3.2.4
•
ROMON bit software switchable in user expanded mode (enable/disable); see Section 3.3.2.1
Note:
†
These options are not available on the MC68HC711PH8; on this device, the security
option is always available, the PLL oscillator is optimized for operation at 32 kHz, the
oscillator buffer is an inverter, the POR/exit from STOP start-up time is 4064 bus cycles
and the ROMON bit is software switchable in user expanded mode.
The Motorola Interconnect Bus (MI BUS) is a serial communications protocol which supports
distributed real-time control efficiently and with a high degree of noise immunity. It allows data
to be transferred between the MCU and the slave device using only one wire, making this type
of communication suitable for medium speed networks requiring very low cost multiplex
wiring.
TPG
MOTOROLA
1-2
INTRODUCTION
MC68HC11PH8
22
1
OC1/PAI
OC1/OC2
OC1/OC3
Timer
OC1/OC4
IC4/OC1/OC5
IC1
Periodic interrupt
IC2
COP watchdog
IC3
SCI1+
PD1
PD0
AD7
AD6
AD5
AD4
AD3
AD2
AD1
AD0
VRH
VRL
PE7
PE6
PE5
PE4
PE3
PE2
PE1
PE0
8-channel
A/D
converter
2048 bytes RAM
VDD
VSS
M68HC11
CPU
Oscillator
3 x Modulus timers
PLL
5
SS2
SCK2
MOSI2
MISO2
TXD2
SCI2+ (with MI BUS)
RXD2
SPI2
LCD
drivers
LCDBP
PWM
5
Keyboard WOI
XTAL
EXTAL
E
XFC
VDDSYN
4XOUT
(see note)
PG7
PG6
PG5
PG4
PG3
PG2
PG1
PG0
PH7
PH6
PH5
PH4
PH3
PH2
PH1
PH0
R/W
Interrupts
&
mode
select
PD5
PD4
PD3
PD2
TXD1
RXD1
768 bytes EEPROM
VPPE/XIRQ
IRQ
RESET
LIR/MODA
VSTBY/MODB
Port D
SS1
SCK1
MOSI1
MISO1
Port E
SPI1
Port G
(including 64 bytes for vectors)
PA7
PA6
PA5
PA4
PA3
PA2
PA1
PA0
Port H
ROM or EPROM
49152 x 8
Port A
Pulse accumulator
PW4
PW3
PW2
PW1
A15
A14
A13
A12
A11
A10
A9
A8
A7
A6
A5
A4
A3
A2
A1
A0
D7
D6
D5
D4
D3
D2
D1
DO
Port F
Port C
PF7
PF6
PF5
PF4
PF3
PF2
PF1
PF0
PC7
PC6
PC5
PC4
PC3
PC2
PC1
PC0
Note: The 4XOUT pin
is available only on the
112-pin TQFP package.
Port B
PB7
PB6
PB5
PB4
PB3
PB2
PB1
PB0
Non-multiplexed address and data buses
Figure 1-1 MC68HC11PH8/MC68HC711PH8 block diagram
TPG
MC68HC11PH8
INTRODUCTION
MOTOROLA
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23
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MOTOROLA
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INTRODUCTION
MC68HC11PH8
24
2
2
PIN DESCRIPTIONS
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
74
73
72
71
70
69
68
67
66
65
64
63
62
61
60
59
58
57
56
55
54
PD2/MISO
PD1/TXD1
PD0/RXD1
MODA/LIR
RESET
XFC
VDDSYN
EXTAL
XTAL
E
VDDR
VSSR
PC7/D7
PC6/D6
PC5/D5
PC4/D4
PC3/D3
PC2/D2
PC1/D1
PC0/D0
IRQ
RXD2/PG0
VDD AD
AD7/PE7
AD6/PE6
AD5/PE5
AD4/PE4
AD3/PE3
AD2/PE2
AD1/PE1
AD0/PE0
VRL
VRH
VSS AD
A7/PF7
A6/PF6
A5/PF5
A4/PF4
A3/PF3
A2/PF2
A1/PF1
A0/PF0
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
PW1/PH0
PW2/PH1
PW3/PH2
PW4/PH3
PH4
PH5
PH6
PH7
MODB/VSTBY
VPPE/XIRQ
VDD
VDDL
VSSL
VSS
R/W/PG7
LCDBP/PG6
SS2/PG5
SCK2/PG4
MOSI2/PG3
MISO2/PG2
TXD2/PG1
84
83
82
81
80
79
78
77
76
75
11
10
9
8
7
6
5
4
3
2
PB0/A8
PB1/A9
PB2/A10
PB3/A11
PB4/A12/LCD4
PB5/A13/LCD5
PB6/A14/LCD6
PB7/A15/LCD7
VSS
VDD
PA0/IC3
PA1/IC2
PA2/IC1
PA3/OC1/OC5/IC4
PA4/OC1/OC4
PA5/OC1/OC3
PA6/OC1/OC2
PA7/OC1/PAI
PD5/SS
PD4/SCK
PD3/MOSI
The MC68HC11PH8 is available in an 84-pin plastic-leaded chip carrier (PLCC) and in an 112-pin thin
quad flat pack (TQFP); in addition to those two packages, the MC68HC711PH8 is also available in an
84-pin windowed cerquad package, to allow the EPROM to be erased. Most pins on this MCU serve
two or more functions, as described in the following paragraphs. Refer to Figure 2-1 and to Figure 2-2
which show the pin assignments for the 84 and 112-pin packages respectively.
Figure 2-1 84-pin PLCC/CERQUAD pinout
TPG
MC68HC11PH8
PIN DESCRIPTIONS
MOTOROLA
2-1
25
NC
NC
PB0/A8
PB1/A9
PB2/A10
PB3/A11
PB4/A12/LCD4
PB5/A13/LCD5
PB6/A14/LCD6
PB7/A15/LCD7
VSS
VDD
PA0/IC3
NC
NC
PA1/IC2
PA2/IC1
PA3/OC1/OC5/IC4
PA4/OC1/OC4
PA5/OC1/OC3
NC
PA6/OC1/OC2
PA7/OC1/PAI
PD5/SS
PD4/SCK
PD3/MOSI
NC
NC
111
110
109
108
107
106
105
104
103
102
101
100
99
98
97
96
95
94
93
92
91
90
89
88
87
86
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
84
83
82
81
80
79
78
77
76
75
74
73
72
71
70
69
68
67
66
65
64
63
62
61
60
59
58
57
NC
PD2/MISO
PD1/TXD
PD0RXD
MODA/LIR
RESET
XFC
VDDSYN
NC
NC
NC
EXTAL
XTAL
E
4XOUT
VDDR
VSSR
PC7/D7
PC6/D6
PC5/D5
PC4/D4
PC3/D3
PC2/D2
PC1/D1
PC0/D0
IRQ
NC
NC
NC
RXD2/PG0
NC
VDDAD
AD7/PE7
AD6/PE6
AD5/PE5
AD4/PE4
AD3/PE3
AD2/PE2
AD1/PE1
AD0/PE0
VRL
NC
NC
VRH
VSSAD
NC
A7/PF7
A6/PF6
A5/PF5
A4/PF4
A3/PF3
A2/PF2
A1/PF1
A0/PF0
NC
NC
NC
NC
PW1/PH0
PW2/PH1
PW3/PH2
PW4/PH3
PH4
PH5
PH6
PH7
NC
MODB/VSTBY
VPPE/XIRQ
NC
VDDL
VSSL
NC
NC
R/W/PG7
LCDBP/PG6
SS2/PG5
SCK2/PG4
MOSI2/PG3
MISO2/PG2
TXD2/PG1
NC
NC
NC
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
2
Figure 2-2 112-pin TQFP pinout
2.1
VDD and VSS
Power is supplied to the microcontroller via these pins. VDD is the positive supply and VSS is
ground. The MCU operates from a single 5V (nominal) power supply.
It is in the nature of CMOS designs that very 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 bypassing at the MCU.
Bypass capacitors should have good high-frequency characteristics and be as close to the MCU as
possible. Bypassing requirements vary, depending on how heavily the MCU pins are loaded.
The MC68HC11PH8 MCU has five VDD pins and five VSS pins. One pair of these pins is reserved for
supplying power to the analog-to-digital converter (VDD AD, VSS AD); two pairs are used for the
internal logic (VDD, VSS); the remaining two pairs supply power for the port logic on either half of the
chip (VDDL, VSSL and VDDR, VSSR). This arrangement minimizes the injection of noise into the
digital circuitry on the chip.
TPG
MOTOROLA
2-2
PIN DESCRIPTIONS
MC68HC11PH8
26
2.2
RESET
An active low bidirectional control signal, RESET, acts as an input to initialize the MCU to a known
start-up state. It also acts as an open-drain output to indicate that an internal failure has been
detected in either the clock monitor or the COP watchdog circuit. The CPU distinguishes between
internal and external reset conditions by sensing whether the reset pin rises to a logic one in less
than four E clock cycles after an internal reset has been released. It is therefore not advisable to
connect an external resistor-capacitor (RC) power-up delay circuit to the reset pin of M68HC11
devices because the circuit charge time constant can cause the device to misinterpret the type of
reset that occurred. Refer to Section 10 for further information.
2
Figure 2-3 illustrates a typical reset circuit that includes an external switch together with a low
voltage inhibit circuit, to prevent power transitions, or RAM or EEPROM corruption.
VDD
VDD
2
4.7 kΩ
IN
RESET
VDD
Manual
reset
1
MC34064
GND
3
To M68HC11
RESET
4.7 kΩ
4.7 kΩ
1µF
2
IN
RESET
1
MC34164
GND
3
Figure 2-3 External reset circuitry
2.3
Crystal driver and external clock input (XTAL, EXTAL)
These two pins provide the interface for either a crystal or a CMOS compatible clock to control the
internal clock generator circuitry. If the PLL circuit is not being used to provide the E clock, the
frequency applied to these pins must be four times higher than the desired E clock rate. Figure 2-4
shows oscillator connections that should be used when the PLL is disabled, and Figure 2-5 shows the
connections that should be used when the PLL is enabled.
TPG
MC68HC11PH8
PIN DESCRIPTIONS
MOTOROLA
2-3
27
2
The XTAL pin is normally left unconnected when an external CMOS compatible clock input is
connected to the EXTAL pin. However, a 10 kΩ to 100 kΩ load resistor connected from XTAL to
ground can be used to reduce RFI noise emission. The XTAL output is normally intended to drive
only a crystal. The XTAL output can be buffered with a high-impedance buffer, or it can be used to
drive the EXTAL input of another M68HC11 family device (unless the PLL circuit is in use, in which
case the 4XOUT output must be used to clock a second device; see Section 2.5).
On the MC68HC11PH8, the type of internal crystal oscillator buffer is determined by a mask
option; it can be either an inverter or a Schmitt trigger. Use of the Schmitt trigger type reduces
problems caused by noise, in particular with slow clocks. At crystal power-up, the Schmitt trigger
will only generate internal clocks when the crystal amplitude is sufficient. However, this type of
buffer requires a larger XTAL amplitude and is not recommended for use with high frequency
crystals, especially if a second MCU is to be driven. This option is not available on the
MC68HC711PH8, on which the crystal oscillator buffer is an inverter.
In all cases, use caution when designing circuitry associated with the oscillator pins.
25 pF
EXTAL
(a) Common crystal
connections
4¥E
crystal
10 MΩ
M68HC11
XTAL
25 pF
EXTAL
(b) External oscillator
connections
External oscillator
M68HC11
XTAL
NC
25 pF
220Ω
EXTAL
EXTAL
10 MΩ
M68HC11
XTAL
4¥E
crystal
M68HC11
NC
25 pF
XTAL
(c) One crystal driving two MCUs
Note: capacitor values include all stray capacitance.
Figure 2-4 Oscillator connections (VDDSYN = 0, PLL disabled)
TPG
MOTOROLA
2-4
PIN DESCRIPTIONS
MC68HC11PH8
28
18 pF
2
EXTAL
(a) Common crystal connections
(32 to 38.4 kHz crystal)
M68HC11
22 MΩ
crystal
XTAL
20 pF
390 kΩ
25 pF
EXTAL
(a) Common crystal connections
(500 to 2000 kHz crystal)
M68HC11
10 MΩ
crystal
XTAL
25 pF
External oscillator
EXTAL
(b) External oscillator
connections
M68HC11
XTAL
NC
Note: capacitor values include all stray capacitance.
Note: all values of capacitance and resistance shown are approximate; exact values must be calculated knowing the crystal parameters
and the expected voltage and temperature ranges.
Figure 2-5 Oscillator connections (VDDSYN = 1, PLL enabled)
2.4
E clock output (E)
E is the output connection for the internally generated E clock. The signal from E is used as a
timing reference. The frequency of the E clock output is one quarter that of the input frequency at
the XTAL and EXTAL pins (except when the PLL is used as the clock source). When E clock output
is low, an internal process is taking place; when it is high, data is being accessed. All clocks,
including the E clock, are halted when the MCU is in STOP mode. The E clock output can be
turned off to reduce the effects of RFI (see Section 3.3.2.5).
TPG
MC68HC11PH8
PIN DESCRIPTIONS
MOTOROLA
2-5
29
2.5
2
Phase-locked loop (XFC, VDDSYN, 4XOUT)
The XFC and VDDSYN pins are the inputs for the on-chip PLL (phase-locked loop) circuitry. On reset,
all system clocks are derived from the internal EXTAL signal (EXTALi). If enabled (VDDSYN high), the
PLL uses the EXTALi frequency as a reference to generate a clock frequency that can be varied under
software control. The user may choose to use the PLL output instead of EXTALi as the source clock
for the system.
The PLL consists of a variable bandwidth loop filter, a voltage controlled oscillator (VCO), a
feedback frequency divider and a digital phase detector. PLL functions are controlled by the
PLLCR and SYNR registers. A block diagram of the PLL circuit is shown in Figure 2-6; refer also
to Figure 8-1.
0.1 µF
VDDSYN
XTAL EXTAL STOP
&
CXFC
XFC
fREF
Phase
detect
PCOMP
Loop Þlter
0.01 µF
BCS
VDDSYN
VCOOUT
VCO
Bus clock
select
fFB
Module clock
select
Frequency divider
4XCLK
To clock
generation
circuitry
ST4XCK
For SCI
and timer
EXTALi
MCS
SYNR
4XOUT clock
select
EXTALi
Key:
4XOUT
External connection
EXT4X
Figure 2-6 PLL circuit
If enabled by the CLK4X bit in the CONFIG register, either the 4XCLK signal or the EXTALi signal
can be output on the 4XOUT pin, depending on the state of the EXT4X bit in the OPT2 register.
Refer to Figure 2-6, and to Section 3 for a description of the CLK4X and EXT4X bits. The signal
output on the 4XOUT pin could be used to clock another MCU.
Note:
The 4XOUT pin is not available on 84-pin packaged devices.
TPG
MOTOROLA
2-6
PIN DESCRIPTIONS
MC68HC11PH8
30
2.5.1
PLL operation
The voltage controlled oscillator (VCO) generates the PLL output frequency VCOOUT. This signal
is fed back through a frequency divider, which divides the signal frequency by a factor determined
by the contents of the SYNR register, to produce the feedback signal fFB. This signal is input to the
phase detector along with the reference signal, fREF. The phase detector generates a control
signal (PCOMP) which is a function of the phase difference between fFB and fREF. PCOMP is then
integrated, and the resultant dc voltage (visible on XFC) is applied to the VCO, modifying the
output signal VCOOUT to lock it in phase with fREF.
Note:
2
Because the operation of the PLL depends on repeated adjustments to the voltage
input to the VCO, a time tPLLS is required for the stabilization of the output frequency.
The state of two bits in the PLLCR register, MCS and BCS, determine whether VCOOUT or
EXTALi is used for the system clocks.
A mask option on the MC68HC11PH8 allows the PLL circuit to be optimized for operation in either
of two frequency ranges, as shown in Table 2-1 (this option is not available on the
MC68HC711PH8; on this device the PLL is optimized for operation at 32kHz). Input frequencies
other than those included in Table 2-1 can be used, but, for operation above the maximum
frequency specified, VDDSYN should be grounded to disable the PLL and enable the high
frequency oscillator circuit; in this state the oscillator is designed for 16MHz operation and XFC
may be left unconnected. Refer also to Figure 2-5.
Table 2-1 PLL mask options
Characteristic
Typical input frequency
Maximum input frequency
Mask option 1 Mask option 2
32 kHz
614 kHz
50 kHz
2 MHz
VDDSYN is the power supply pin for the PLL and should be suitably bypassed. Connecting it high
enables the internal low frequency oscillator circuitry designed for the PLL. The external capacitor
on XFC (CXFC) should be located as close to the chip as possible to minimize noise. In general,
a larger capacitor will improve the PLL’s frequency stability, at the expense of increasing the time
required for it to settle (tPLLS) at the desired frequency. A capacitor value of 47nF is usually
adequate for either 32kHz or 614kHz applications. Refer to Section A.5.2 for PLL control timing
information.
The PLL filter has two bandwidths that can be manually selected under control of the BWC bit in
PLLCR. Whenever the PLL is first enabled, the wide bandwidth mode should be used, to enable
the PLL frequency to ramp up quickly. After a time tPLLS has elapsed, the filter can be switched to
the narrow bandwidth mode, to make the final frequency more stable.
Warning: Bit 5 of the PLLCR (AUTO) must be cleared before an attempt is made to use BWC;
manual bandwidth control should always be used.
TPG
MC68HC11PH8
PIN DESCRIPTIONS
MOTOROLA
2-7
31
2.5.2
2
Synchronization of PLL with subsystems
If the MCS bit in PLLCR is set, then the SCI and timer clocks run off the PLL output (4XCLK) as
does the CPU. If MCS is cleared, then the timer and SCI subsystems operate off the EXTALi
frequency, but are accessed by the CPU relative to the internal PH2 signal. In this case, although
EXTALi is used as the reference for the PLL, the PH2 clock and the module clocks for the timer
and the SCI are not synchronized. In order to ensure synchronized data, special circuitry has been
incorporated into both subsystems.
2.5.3
Changing the PLL frequency
The PLL output frequency can be changed by altering the contents of the SYNR register (see
Section 2.5.4.2). To prevent possible bursts of high frequency operation during the reconfiguration
of the PLL, the following sequence should be performed:
1) Switch to the low frequency bus rate (BCS = 0).
2) Disable the PLL (PLLON = 0).
3) Change the value in SYNR.
4) Enable the PLL (PLLON = 1).
5) Wait a time tPLLS for the PLL frequency to stabilize.
6) Switch to the high frequency bus rate (BCS = 1).
2.5.4
PLL registers
Two registers are used to control the operation of the MC68HC11PH8 phase locked loop circuitry.
These are the PLL control register and the synthesizer program register, each of which is
described below.
TPG
MOTOROLA
2-8
PIN DESCRIPTIONS
MC68HC11PH8
32
2.5.4.1
PLLCR — PLL control register
Address
PLL control (PLLCR)
bit 7
$002E PLLON
bit 6
bit 5
bit 4
bit 3
BCS
AUTO
BWC
VCOT
bit 2
bit 1
bit 0
MCS T16EN WEN
State
on reset
2
x010 1010
This read/write register contains two bits that are used to enable and disable the synthesizer and
to switch from slow (EXTALi) to one of the fast speeds. Two further bits are used to control the filter
bandwidth. The SCI, timer, timer clock source and the slow clock for WAIT mode are also
controlled by this register.
PLLON — PLL on
1 (set)
–
Switch PLL on.
0 (clear) –
Switch PLL off.
This bit activates the synthesizer circuit without connecting it to the control circuit. This allows the
circuit to stabilize before it drives the CPU clocks.
On reset, PLLON is forced low if the VDDSYN supply is low. If VDDSYN is at VDD, PLLON is set
by reset to allow the control loop to stabilize during power-up. PLLON cannot be cleared whilst
using VCOOUT to drive the internal processor clock, i.e. when BCS is set.
BCS — Bus clock select
1 (set)
–
0 (clear) –
VCOOUT output drives the clock circuit (4XCLK).
EXTALi drives the clock circuit (4XCLK).
This bit determines which signal drives the clock circuit generating the bus clocks. Once BCS has
been altered it can take up to [1.5 EXTALi + 1.5 VCOOUT] cycles for the change in the clock to
occur. Reset clears this bit.
Note:
PLLON and BCS have built-in safeguards so that VCOOUT cannot be selected as the
clock source (BCS = 1) if the PLL is off (PLLON = 0). Similarly, the PLL cannot be
turned off (PLLON = 0) if it is on and in use (BCS = 1). Turning the PLL on and selecting
VCOOUT as the clock source therefore requires two independent writes to PLLCR.
AUTO — Automatic bandwidth control (Test mode only)
1 (set)
–
0 (clear) –
Automatic bandwidth control selected.
Manual bandwidth control selected.
Reset sets this bit.
Warning: This bit must be cleared before an attempt is made to use BWC; manual bandwidth
control should always be used.
TPG
MC68HC11PH8
PIN DESCRIPTIONS
MOTOROLA
2-9
33
BWC — Bandwidth control
2
1 (set)
–
0 (clear) –
Wide (high and low) bandwidth control selected.
Narrow (low) bandwidth control selected.
Bandwidth selection can only be controlled by BWC when AUTO is cleared. After the PLL is first
enabled, or after a change in frequency, a delay of tPLLS is required before clearing BWC. The low
bandwidth driver is always enabled, so this bit determines whether the high bandwidth driver is on
or off. Reset clears this bit.
VCOT — VCO test (Test mode only)
1 (set)
–
0 (clear) –
Loop filter operates as specified by AUTO and BWC.
Low bandwidth mode of the PLL filter is disabled.
This bit is used to isolate the loop filter from the VCO for testing purposes. VCOT is always set in
user modes. This bit is writable only in bootstrap and test modes. Reset sets this bit.
MCS — Module clock select
1 (set)
–
4XCLK is the source for the SCI and timer divider chain.
0 (clear) –
EXTALi is the source for the SCI and timer divider chain.
Reset clears this bit.
T16EN — 16-bit timer clock enable (refer to Section 8)
1 (set)
–
16-bit timer clock enabled.
0 (clear) –
16-bit timer clock disabled.
WEN — WAIT enable
1 (set)
–
0 (clear) –
Low-power WAIT mode selected (PLL set to ‘idle’ in WAIT mode).
Do not alter the 4XCLK during WAIT mode.
This bit determines whether the 4XCLK is disconnected from VCOOUT during WAIT and
connected to EXTALi. Reset clears this bit.
When WEN is set, the CPU will respond to a WAIT instruction by first stacking the relevant
registers, then by clearing BCS and setting the PLL to ‘idle’, with modulus = 1. BWC is set so that
the wide bandwidth control is selected.
Any interrupt, any reset, or the assertion of RAF (receiver active flag) in either of the SCIs will allow
the PLL to resume operating at the frequency specified in the SYNR. The user must set BCS after
the PLL has had time to adjust (tPLLS). If, for a specific SCI, the RE bit (receiver enable bit) is clear,
then RAF cannot become set, hence the PLL will not resume normal operation. For a description
of RAF and RE, see Section 5.
TPG
MOTOROLA
2-10
PIN DESCRIPTIONS
MC68HC11PH8
34
2.5.4.2
SYNR — Synthesizer program register
Address
Synthesizer program (SYNR)
bit 7
bit 6
bit 5
bit 4
bit 3
bit 2
bit 1
bit 0
State
on reset
2
$002F SYNX1 SYNX0 SYNY5 SYNY4 SYNY3 SYNY2 SYNY1 SYNY0 0000 1011
The PLL frequency synthesizer multiplies the frequency of the input oscillator. The multiplication
factor is software programmable via a loop divider, which consists of a six-bit modulo N counter,
with a further two bit scaling factor.
The multiplication factor is given by 2(Y + 1)2X, where 0 ≤ X ≤ 3 and 0 ≤ Y ≤ 63.
Bits in SYNR can be read at any time but can only be written if PLLON = 0.
Note:
Exceeding recommended operating frequencies can result in indeterminate MCU
operation.
SYNX[1:0]
These bits program the binary taps (divide by 1, 2, 4 and 8). Reset clears these bits.
SYNY[5:0]
These bits program the six-bit modulo N (1 to 64) counter. Reset sets these bits to %001011.
Note:
The resolution of the multiplication factors decreases by a factor of two, as X increases:
X
0
1
2
3
Y
0 Ð 63
0 Ð 63
0 Ð 63
0 Ð 63
Possible multipliers
2, 4, 6, 8, É, 128
4, 8, 12, 16, É, 256
8, 16, 24, 32, É, 512
16, 32, 48, 64, É, 1024
TPG
MC68HC11PH8
PIN DESCRIPTIONS
MOTOROLA
2-11
35
2.6
2
Interrupt request (IRQ)
The IRQ input provides a means of applying asynchronous interrupt requests to the MCU. Either
falling edge sensitive triggering or level sensitive triggering is program selectable (OPTION
register). IRQ is always configured to level sensitive triggering at reset.
Note:
Connect an external pull-up resistor, typically 4.7 kΩ, to VDD when IRQ is used in a level
sensitive wired-OR configuration. See also Section 2.7.
2.7
Nonmaskable interrupt (XIRQ/VPPE)
The XIRQ input provides a means of requesting a nonmaskable interrupt after reset initialization.
During reset, the X bit in the condition code register (CCR) is set and any interrupt is masked until
MCU software enables it. Because the XIRQ input is level-sensitive, it can be connected to a
multiple-source wired-OR network with an external pull-up resistor to VDD. XIRQ is often used as
a power loss detect interrupt.
Whenever XIRQ or IRQ is used with multiple interrupt sources (IRQ must be configured for level
sensitive operation if there is more than one source of IRQ interrupt), each source must drive the
interrupt input with an open-drain type of driver to avoid contention between outputs. There should
be a single pull-up resistor near the MCU interrupt input pin (typically 4.7 kΩ). There must also be
an interlock mechanism at each interrupt source so that the source holds the interrupt line low until
the MCU recognizes and acknowledges the interrupt request. If one or more interrupt source is
still pending after the MCU services a request, the interrupt line will still be held low and the MCU
will be interrupted again as soon as the interrupt mask bit in the MCU is cleared (normally upon
return from an interrupt). Refer to Section 10.
On the MC68HC711PH8, the VPPE pin is used to input the external EPROM programming
voltage, which must be present during EPROM programming.
TPG
MOTOROLA
2-12
PIN DESCRIPTIONS
MC68HC11PH8
36
2.8
MODA and MODB (MODA/LIR and MODB/VSTBY)
2
During reset, MODA and MODB select one of the four operating modes. Refer to Section 3.
After the operating mode has been selected, the LIR pin provides an open-drain output (driven
low) to indicate that execution of an instruction has begun. In order to detect consecutive
instructions in a high-speed application, this signal drives high for a short time to prevent false
triggering. A series of E clock cycles occurs during execution of each instruction. The LIR signal
goes low during the first E clock cycle of each instruction (opcode fetch). This output is provided
for assistance in program debugging and its operation is controlled by the LIRDV bit in the OPT2
register.
The VSTBY pin is used to input RAM stand-by power. The MCU is powered from the VDD pin
unless the difference between the level of VSTBY and VDD is greater than one MOS threshold
(about 0.7 volts). When these voltages differ by more than 0.7 volts, the internal 1024-byte RAM
and part of the reset logic are powered from VSTBY rather than VDD. This allows RAM contents
to be retained without VDD power applied to the MCU. Reset must be driven low before VDD is
removed and must remain low until VDD has been restored to a valid level.
VDD
4.7kΩ
VDD
4.8 V NiCd
VOUT
To MODB/VSTBY
pin of M68HC11
MAX 690
(+)
VBATT
Figure 2-7 RAM stand-by connections
2.9
VRH and VRL
These pins provide the reference voltages for the analog-to-digital converter.
2.10
PG7/R/W
This pin provides two separate functions, depending on the operating mode. In single chip and
bootstrap modes, PG7/R/W acts as input/output port G bit 7. Refer to Section 4 for further information.
In expanded and test modes, PG7/R/W performs the read/write function. PG7/R/W signals the
direction of transfers on the external data bus. A high on this pin indicates that a read cycle is in
progress.
TPG
MC68HC11PH8
PIN DESCRIPTIONS
MOTOROLA
2-13
37
2.11
2
Port signals
62 pins on the device are arranged into seven 8-bit ports: A, B, C, E, F, G, and H, and one six-bit
port (D). The lines of ports A, B, C, D, F, G, and H are fully bidirectional; E is input only. Each of
the bidirectional ports serves a purpose other than I/O, depending on the operating mode or
peripheral function selected. Note that ports B, C, F, and one bit of port G are available for I/O
functions only in single chip and bootstrap modes. Refer to Table 2-2 for details of the port signals’
functions in different operating modes.
Note:
When using the information about port functions, do not confuse pin function with the
electrical state of the pin at reset. All general purpose I/O pins configured as inputs at
reset are in a high-impedance state. Port data registers reflect the functional state of
the port at reset. The pin function is mode dependent.
2.11.1
Port A
Port A is an 8-bit general purpose I/O port with a data register (PORTA) and a data direction
register (DDRA). Port A pins share functions with the 16-bit timer system (see Section 8 for further
information). PORTA can be read at any time and always returns the pin level. If written, PORTA
stores the data in internal latches. The pins are driven only if they are configured as outputs. Writes
to PORTA do not change the pin state when the pins are configured for timer output compares.
Out of reset, port A pins [7:0] are general purpose high-impedance inputs. When the functions
associated with these pins are disabled, the bits in DDRA govern the I/O state of the associated
pin. For further information, refer to Section 4.
2.11.2
Port B
Port B is an 8-bit general purpose I/O port with a data register (PORTB) and a data direction
register (DDRB). In single chip mode, port B pins are general purpose I/O pins (PB[7:0]). In
expanded mode, port B pins act as the high-order address lines (A[15:8]) of the address bus. In
either of these modes, the four high-order port B pins (B[7:4]) may be configured to drive four LCD
segments (see Section 2.12)
PORTB can be read at any time and always returns the pin level. If PORTB is written, the data is
stored in internal latches. The pins are driven only if they are configured as outputs in single chip
or bootstrap mode. For further information, refer to Section 4.
Port B pins include on-chip pull-up devices which can be enabled or disabled via the port pull-up
assignment register (PPAR).
TPG
MOTOROLA
2-14
PIN DESCRIPTIONS
MC68HC11PH8
38
Table 2-2 Port signal functions
Port/bit
PA0
PA1
PA2
PA3
PA4
PA5
PA6
PA7
PB[3:0]
PB4
PB5
PB6
PB7
PC[7:0]
PD0
PD1
PD2
PD3
PD4
PD5
PE[7:0]
PF[7:0]
PG0
PG1
PG2
PG3
PG4
PG5
PG6
PG7
PH0
PH1
PH2
PH3
PH4
PH5
PH6
PH7
2
Single chip
and
bootstrap mode
Expanded multiplexed
and
special test mode
PA0/IC3
PA1/IC2
PA2/IC1
PA3/OC5/IC4 and/or OC1
PA4/OC4 and/or OC1
PA5/OC3 and/or OC1
PA6/OC2 and/or OC1
PA7/PAI and/or OC1
PB[3:0]
A[11:8]
PB4/LCD4
A12/LCD4
PB5/LCD5
A13/LCD5
PB6/LCD6
A14/LCD6
PB7/LCD7
A15/LCD7
PC[7:0]
D[7:0]
PD0/RXD1
PD1/TXD1
PD2/MISO1
PD3/MOSI1
PD4/SCK1
PD5/SS1
Input only or analog inputs
PF[7:0]
A[7:0]
PG0/RXD2
PG1/TXD2
PG2/MISO2
PG3/MOSI2
PG4/SCK2
PG5/SS2
PG6/LCDBP
PG7
R/W
PH0/PW1
PH1/PW2
PH2/PW3
PH3/PW4
PH4
PH5
PH6/Modulus timer C clock input
PH7/Modulus timer B clock input
TPG
MC68HC11PH8
PIN DESCRIPTIONS
MOTOROLA
2-15
39
2.11.3
2
Port C
Port C is an 8-bit general purpose I/O port with a data register (PORTC) and a data direction
register (DDRC). In single chip mode, port C pins are general purpose I/O pins (PC[7:0]). In the
expanded mode, port C pins are configured as data bus pins (D[7:0]).
PORTC can be read at any time and always returns the pin level. If PORTC is written, the data is
stored in internal latches. The pins are driven only if they are configured as outputs in single chip
or bootstrap mode. Port C pins are general purpose inputs out of reset in single chip and bootstrap
modes. In expanded and test modes, these pins are data bus lines out of reset.
The CWOM control bit in the OPT2 register disables port C’s p-channel output drivers. Because
the n-channel driver is not affected by CWOM, setting CWOM causes port C to become an
open-drain-type output port suitable for wired-OR operation. In wired-OR mode (PORTC bits at
logic level zero), the pins are actively driven low by the n-channel driver. When a port C bit is at
logic level one, the associated pin is in a high impedance state as neither the n-channel nor the
p-channel devices are active. It is customary to have an external pull-up resistor on lines that are
driven by open-drain devices. Port C can only be configured for wired-OR operation when the
MCU is in single chip mode. For further information, refer to Section 4.
2.11.4
Port D
Port D, a 6-bit general purpose I/O port, has a data register (PORTD) and a data direction register
(DDRD). The six port D lines (D[5:0]) can be used for general purpose I/O, for one of the serial
communications interfaces (SCI1, pins [1,0]) and for one of the serial peripheral interfaces (SPI1,
pins [5:2]).
PORTD can be read at any time; inputs return the pin level and outputs return the pin driver input
level. If PORTD is written, the data is stored in internal latches. The pins are driven only if port D
is configured for general purpose output.
The DWOM bit in SPCR disables the p-channel output drivers of pins D[5:2], and the WOMS bit
in SCCR1 disables those of pins D[1,0]. Because the n-channel driver is not affected by DWOM
or WOMS, setting either bit causes the corresponding port D pins to become open-drain-type
outputs suitable for wired-OR operation. In wired-OR mode (PORTD bits at logic level zero), the
pins are actively driven low by the n-channel driver. When a port D bit is at logic level one, the
associated pin is in a high impedance state as neither the n-channel nor the p-channel devices
are active. It is customary to have an external pull-up resistor on lines that are driven by open-drain
devices. Port D can be configured for wired-OR operation when the MCU is in single chip mode
or expanded mode.
For further information, refer to Section 4, Section 5 (SCI) and Section 7 (SPI).
TPG
MOTOROLA
2-16
PIN DESCRIPTIONS
MC68HC11PH8
40
2.11.5
Port E
Port E, PE/AD[7:0], is an input-only port that can also be used as the analog inputs for the
analog-to-digital converter.
2
For further information, refer to Section 4 and Section 9 (A/D).
2.11.6
Port F
Port F is an 8-bit general purpose I/O port with a data register (PORTF) and a data direction
register (DDRF). In single chip mode, port F pins are general purpose I/O pins (PF[7:0]). In
expanded mode, port F pins act as the low-order address lines (A[7:0]) of the address bus.
PORTF can be read at any time and always returns the pin level. If PORTF is written, the data is
stored in internal latches. The pins are driven only if they are configured as outputs in single chip
or bootstrap mode.
Port F pins include on-chip pull-up devices that can be enabled or disabled via the port pull-up
assignment register (PPAR). For further information, refer to Section 4.
2.11.7
Port G
In normal modes, Port G is an 8-bit general purpose I/O port with a data register (PORTG) and a
data direction register (DDRG). Port G pin 7 is the R/W line in expanded mode; pin 6 can be used
for the LCD backplane signal (LCDBP) in any mode; the remaining pins can be used for general
purpose I/O, for one of the SCI subsystems (SCI2 with MI-bus, pins [1,0]), or for one of the serial
peripheral interface subsystems (SPI2, pins [5:2]).
PORTG can be read at any time; inputs return the pin level and outputs return the pin driver input
level. If PORTG is written, the data is stored in internal latches. The pins are driven only if they are
configured as outputs (and only in single chip or bootstrap mode for pins G[7,6]).
The GWOM bit in SP2CR disables the p-channel output drivers of pins G[5:2], and the WOMS2
bit in S2CR1 disables those of pins G[1,0]. Because the n-channel driver is not affected by GWOM
or WOMS2, setting either bit causes the corresponding port G pins to become open-drain-type
outputs suitable for wired-OR operation. In wired-OR mode (appropriate PORTG bits at logic level
zero), the pins are actively driven low by the n-channel driver. When a port G bit is at logic level
one, the associated pin is in a high impedance state as neither the n-channel nor the p-channel
devices are active. It is customary to have an external pull-up resistor on lines that are driven by
open-drain devices. Port G pins [5:0] can be configured for wired-OR operation when the MCU is
in single chip mode or expanded mode.
Port G pins include on-chip pull-up devices that can be enabled or disabled via the port pull-up
assignment register (PPAR). For further information, refer to Section 4, Section 5 (SCI), Section 6
(MI BUS) and Section 7 (SPI).
TPG
MC68HC11PH8
PIN DESCRIPTIONS
MOTOROLA
2-17
41
2.11.8
2
Port H
Port H is an 8-bit general purpose I/O port with a data register (PORTH) and a data direction
register (DDRH). Port H pins support either input/output, pulse-width modulation channels (pins
[3:0]) or act as clock inputs for two of the 8-bit modulus timers (pins [7,6]).
PORTH can be read at any time and always returns the pin level.
Port H pins include on-chip pull-up devices that can be enabled or disabled via the port pull-up
assignment register (PPAR). Port H pins can be configured for wired-OR interrupt to wake-up from
WAIT or STOP mode under control of the wired-OR interrupt register (WOIEH).
For further information, refer to Section 4 and Section 8 (timer system).
2.12
LCD module
The MC68HC11PH8 incorporates an LCD module that allows four LCD segments to be driven
under control of the LCD control and data register. The four frontplane signals are output on port
B pins [7:4], with the backplane signal output on PG6. A segment is ON when the corresponding
frontplane and backplane are equal in frequency and opposite in phase. The LCD function can be
enabled in any mode.
2.12.1
LCDR — LCD control and data register
LCD control and data (LCDR)
Address
bit 7
bit 6
bit 5
bit 4
bit 3
bit 2
$002D
LCD7
LCD6
LCD5
LCD4
0
0
bit 1
bit 0
State
on reset
LCDCK LCDE 0000 0000
LCD[7:4] — LCD segment data
1 (set)
–
0 (clear) –
Segment ON (corresponding LCD output port B is opposite in phase
to LCDBP).
Segment OFF (corresponding LCD output port B is in phase with
LCDBP).
When LCD[7:4] are all cleared, the LCD backplane is forced low† and all the LCD segments are
off, thus reducing power consumption and RFI emissions.
†
This is not the case on early versions of the MC68HC711PH8; contact your local Motorola
Sales Representative for more information.
TPG
MOTOROLA
2-18
PIN DESCRIPTIONS
MC68HC11PH8
42
LCDCK — LCD frequency clock select
1 (set)
–
0 (clear) –
2
The clock source of the real time interrupt (RTI) toggles LCDBP.
8-bit modulus timer A underflow (CLK64) toggles LCDBP.
When the PLL clock generation circuit is not used (VDDSYN = 0), setting LCDCK selects the
ST4XCK clock divided by 218 as the LCD clock source. Conversely, when the PLL clock
generation circuit is used (VDDSYN = 1), setting LCDCK selects the output of the 8-bit modulus
timer A divided by 23 (CLK64/23) as the LCD clock source. Refer to Section 8.
LCDE — LCD function enable
1 (set)
–
LCD function enabled.
0 (clear) –
LCD function disabled.
The LCDE bit can be written only once (the first write to this register after reset will prevent later
updates of this bit). When enabled, this function will force PG6 into output mode. This output will
be the backplane signal (LCDBP) for the four LCD segments. The four port B pins (PB[7:4]) used
to drive the LCD segments will also be forced into output mode. If enabled in expanded modes,
PB[7:4] will operate as LCD outputs, while PB3 to PB0 output the address lines to access external
resources. To avoid conflicts caused by the LCDE bit being set accidentally by program error, it is
recommended that the LCDE bit be written to zero if the LCD function is not required.
TPG
MC68HC11PH8
PIN DESCRIPTIONS
MOTOROLA
2-19
43
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MOTOROLA
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PIN DESCRIPTIONS
MC68HC11PH8
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1
2
3
3
OPERATING MODES AND ON-CHIP MEMORY
4
This section contains information about the modes that define MC68HC11PH8 operating conditions,
and about the on-chip memory that allows the MCU to be configured for various applications.
3.1
Operating modes
6
The values of the mode select inputs MODB and MODA during reset determine the operating
mode (See Table 3-4). Single chip and expanded modes are the normal modes. In single chip
mode only on-board memory is available. Expanded mode, however, allows access to external
memory. Each of these two normal modes is paired with a special mode. Bootstrap, a variation of
the single chip mode, is a special mode that executes a bootloader program in an internal
bootstrap ROM. Test is a special mode that allows privileged access to internal resources.
3.1.1
5
Single chip operating mode
In single chip operating mode, the MC68HC11PH8 microcontroller has no external address or
data bus. Ports B, C, F, and the R/W pin are available for general purpose parallel I/O.
7
8
9
10
3.1.2
Expanded operating mode
In expanded operating mode, the MCU can access a 64K byte physical address space. The
address space includes the same on-chip memory addresses used for single chip mode, in
addition to external memory and peripheral devices.
The expansion bus is made up of ports B, C, and F, and the R/W signal. In expanded mode, high
order address bits are output on the port B pins, low order address bits on the port F pins, and the
data bus on port C. The R/W/PG7 pin signals the direction of data transfer on the port C bus.
When internal resources are accessed in expanded mode, the last external address can be held on
the output pins (A[15:0]) in order to reduce radio-frequency interference (RFI) emissions. This function
is controlled by the FREEZ bit in the CONFIG register. See Section 3.3.2.1 for a description of this bit.
To allow access to slow peripherals, off chip accesses can be extended by one E clock cycle, under
control of the STRCH and STRX bits (in the OPT2 and INIT2 registers respectively). The E clock
11
12
13
14
➡ 15
TPG
MC68HC11PH8
OPERATING MODES AND ON-CHIP MEMORY
MOTOROLA
3-1
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stretches externally, but the internal clocks are not affected so that timers and serial systems are not
corrupted. See Section 3.3.2.5.
EEPROM data can be protected while in expanded mode, using a security feature described in
Section 3.4.4.
3.1.3
Special test -mode
Special test, a variation of the expanded mode, is primarily used during Motorola’s internal
production testing; however, it is accessible for programming the CONFIG register, programming
calibration data into EEPROM, and supporting emulation and debugging during development.
5
3.1.4
6
7
8
9
Special bootstrap mode
When the MCU is reset in special bootstrap mode, a small on-chip ROM is enabled at address
$BE40–$BFFF. The ROM contains a reset vector and a bootloader program. The MCU fetches the
reset vector, then executes the bootloader.
For normal use of the bootloader program, send a synchronization byte $FF to the SCI receiver
at either E clock ÷256, or E clock ÷1664 (7812 or 1200 baud respectively, for an E clock of 2MHz).
Then download up to 2048 bytes of program data (which is put into RAM starting at $0080). These
characters are echoed through the transmitter. The bootloader program ends the download after
a timeout of four character times or 2048 bytes. When loading is complete, the program jumps to
location $0080 and begins executing the code. Use of an external pull-up resistor is required when
using the SCI transmitter pin (TXD) because port D pins are configured for wired-OR operation by
the bootloader. In bootstrap mode, the interrupt vectors point to RAM. This allows the use of
interrupts through a jump table.
10
Further baud rate options are available on the MC68HC11PH8 by using a different value for the
synchronization byte, as shown in the Table 3-1.
11
A special mode exists that allows a low frequency crystal to be used if the PLL is active. In this case,
the value on port F is loaded into the SYNR register just after reset, to be used as the multiplication
factor for the crystal frequency. If the PLL is not active, then the bootloader runs at the crystal
frequency. Refer to Section 2.5 for more information on the operation of the PLL circuitry.
12
Refer also to Motorola application note AN1060, M68HC11 Bootstrap Mode (the bootloader
mode is similar to that used on the MC68HC11K4).
13
14
15
➡
TPG
MOTOROLA
3-2
OPERATING MODES AND ON-CHIP MEMORY
MC68HC11PH8
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1
Table 3-1 Example bootloader baud rates
Sync.
byte
$FF
$FF
$F0
$FD
$FD
3.2
2
Timeou
Baud rates for an E clock of:
t
delay 2.00MHz 2.10MHz 3.00MHz 3.15MHz 4.00MHz
4 char.
7812
8192
11718
12288
15624
4
1200
1260
1800
1890
2400
4.9
9600
10080
14400
15120
19200
17.3
5208
5461
7812
8192
10416
13
3906
4096
5859
6144
7812
3
4
5
On-chip memory
The MC68HC11PH8 MCU includes 2K bytes of on-chip RAM, 48K bytes of ROM/EPROM and 768
bytes of EEPROM. The bootloader ROM occupies a 512 byte block of the memory map. The
CONFIG register is implemented as a separate EEPROM byte.
6
7
Start
address
$0000
$0080
$0880
Register
block
RAM
2K bytes
$0D00
$1000
$x000  Each of these blocks

$x07F  can be mapped to any
$x080  4K page boundary,
$x87F
8
 using the INIT register.
EEPROM $xD00
768 bytes $xFFF
This block may be remapped
to any 4K page, using INIT2.
BootROM $BE40
Special bootstrap mode only.
Vectors
$4000
$BFFF
10
$4000
$BE40
48K bytes ROM
(MC68HC11PH8) or
48K bytes EPROM
(MC68HC711PH8).
NVM
48K bytes
$C000
Can be mapped to either
$0000Ð$BFFF or
$4000Ð$FFFF,
using the CONFIG register.
11
Normal mode vectors.
12
$FFBF
$FFC0
Ñ$FFFF
Vectors
Single
chip
Expanded
Special
bootstrap
$FFFF
9
Special modes only.
Special
test
13
Figure 3-1 MC68HC11PH8/MC68HC711PH8 memory map
14
➡ 15
TPG
MC68HC11PH8
OPERATING MODES AND ON-CHIP MEMORY
MOTOROLA
3-3
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3.2.1
2
3
4
5
6
7
8
9
10
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Mapping allocations
Memory locations for on-chip resources are the same for both expanded and single chip modes. The
128-byte register block originates at $0000 after reset and can be placed at any other 4K boundary
($x000) after reset by writing an appropriate value to the INIT register. Refer to Figure 3-1, which shows
the memory map.
The on-board 2K byte RAM is initially located at $0080 after reset. The RAM is divided into two
sections, of 128 bytes and 1920 bytes. If RAM and registers are both mapped to the same 4K
boundary, RAM starts at $x080 and 128 bytes are remapped at $x800–$x87F. Otherwise, RAM
starts at $x000. See Figure 3-3.
Remapping is accomplished by writing appropriate values into the two nibbles of the INIT register.
See Section 3.3.2.2.
The 768-byte EEPROM is initially located at $0D00 after reset, when EEPROM is enabled in the
memory map by the CONFIG register. EEPROM can be placed in any other 4K page ($xD00) by
writing to the INIT2 register.
The ROMAD and ROMON bits in the CONFIG register control the position and presence of ROM,
or EPROM, in the memory map. In special test mode, the ROMON bit is cleared so the ROM is
removed from the memory map. In single chip mode, the ROMAD bit is set to one after reset,
which enables the ROM at $4000–$FFFF. In expanded mode, the ROM may be enabled from
$0000–$BFFF (ROMAD = 0) to allow an external memory to contain the interrupt vectors and
initialization code.
In special bootstrap mode, a bootloader ROM is enabled at locations $BE40–$BFFF. The vectors
for special bootstrap mode are contained in the bootloader program. The boot ROM occupies a
512 byte block of the memory map, though not all locations are used.
3.2.1.1
RAM
The MC68HC11PH8 has 2K bytes of fully static RAM that are used for storing instructions,
variables and temporary data during program execution. RAM can be placed at any 4K boundary
in the 64K byte address space by writing an appropriate value to the INIT register.
By default, RAM is initially located at $0080 in the memory map. Direct addressing mode can
access the first 128 locations of RAM using a one-byte address operand. Direct mode accesses
save program memory space and execution time. Registers can be moved to other boundaries to
allow 256 bytes of RAM to be located in direct addressing space. See Figure 3-3.
The on-chip RAM is a fully static memory. RAM contents can be preserved during periods of
processor inactivity by either of two methods, both of which reduce power consumption:
14
15
➡
TPG
MOTOROLA
3-4
OPERATING MODES AND ON-CHIP MEMORY
MC68HC11PH8
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1) During the software-based STOP mode, MCU clocks are stopped, but the
MCU continues to draw power from VDD. Power supply current is directly
related to operating frequency in CMOS integrated circuits and there is very
little leakage when the clocks are stopped. These two factors reduce power
consumption while the MCU is in STOP mode.
2
3
2) To reduce power consumption to a minimum, VDD can be turned off, and the
MODB/VSTBY pin can be used to supply RAM power from either a battery
back-up or a second power supply. Although this method requires external
hardware, it is very effective. Refer to Section 2 for information about how to
connect the stand-by RAM power supply and to Section 10 for a description
of low power operation.
3.2.1.2
4
5
ROM and EPROM
The MCU has 48K bytes of ROM/EPROM. The ROM/EPROM array is enabled when the ROMON
bit in the CONFIG register is set to one (erased). The ROMAD bit in CONFIG places the
ROM/EPROM at either $4000–$FFFF (ROMAD = 1) or at $0000–$BFFF (ROMAD = 0) when
coming out of reset in expanded mode.
3.2.1.3
6
7
Bootloader ROM
The bootloader ROM is enabled at address $BE40–$BFFF during special bootstrap mode. The
reset vector is fetched from this ROM and the MCU executes the bootloader firmware. In normal
modes, the bootloader ROM is disabled.
3.2.2
1
8
9
Registers
In Table 3-2, a summary of registers and control bits, the registers are shown in ascending order
within the 128-byte register block. The addresses shown are for default block mapping
($0000–$007F), however, the INIT register remaps the block to any 4K page ($x000–$x07F). See
Section 3.3.2.2.
10
11
12
13
14
➡ 15
TPG
MC68HC11PH8
OPERATING MODES AND ON-CHIP MEMORY
MOTOROLA
3-5
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Table 3-2 Register and control bit assignments (Sheet 1 of 4)
2
3
4
5
6
7
8
9
10
11
12
13
14
15
Register name
Address bit 7
bit 6
bit 5
bit 4
bit 3
bit 2
bit 1
bit 0
State
on reset
PA0
undeÞned
Port A data (PORTA)
$0000
PA7
PA6
PA5
PA4
PA3
PA2
PA1
Data direction A (DDRA)
$0001
DDA7
DDA6
DDA5
DDA4
DDA3
DDA2
DDA1
DDA0 0000 0000
Data direction B (DDRB)
$0002
DDB7
DDB6
DDB5
DDB4
DDB3
DDB2
DDB1
DDB0 0000 0000
Data direction F (DDRF)
$0003
DDF7
DDF6
DDF5
DDF4
DDF3
DDF2
DDF1
DDF0 0000 0000
Port B data (PORTB)
$0004
PB7
PB6
PB5
PB4
PB3
PB2
PB1
PB0
undeÞned
Port F data (PORTF)
$0005
PF7
PF6
PF5
PF4
PF3
PF2
PF1
PF0
undeÞned
PC7
PC6
PC5
PC4
PC3
PC2
PC1
PC0
undeÞned
Port C data (PORTC)
$0006
Data direction C (DDRC)
$0007
DDC7 DDC6 DDC5 DDC4 DDC3 DDC2 DDC1 DDC0 0000 0000
Port D data (PORTD)
$0008
0
0
Data direction D (DDRD)
$0009
0
0
PD5
PD4
PD3
PD2
PD1
PD0
undeÞned
DDD5 DDD4 DDD3 DDD2 DDD1 DDD0 0000 0000
Port E data (PORTE)
$000A
PE7
PE6
PE5
PE4
PE3
PE2
PE1
PE0
undeÞned
Timer compare force (CFORC)
$000B
FOC1
FOC2
FOC3
FOC4
FOC5
0
0
0
0000 0000
Output compare 1 mask (OC1M)
$000C OC1M7 OC1M6 OC1M5 OC1M4 OC1M3
0
0
0
0000 0000
Output compare 1 data (OC1D)
$000D OC1D7 OC1D6 OC1D5 OC1D4 OC1D3
0
0
0
0000 0000
Timer count (TCNT) high
$000E (bit 15)
(14)
(13)
(12)
(11)
(10)
(9)
(bit 8) 0000 0000
Timer count (TCNT) low
$000F
(bit 7)
(6)
(5)
(4)
(3)
(2)
(1)
(bit 0) 0000 0000
Timer input capture 1 (TIC1) high
$0010
(bit 15)
(14)
(13)
(12)
(11)
(10)
(9)
(bit 8)
undeÞned
Timer input capture 1 (TIC1) low
$0011
(bit 7)
(6)
(5)
(4)
(3)
(2)
(1)
(bit 0)
undeÞned
Timer input capture 2 (TIC2) high
$0012
(bit 15)
(14)
(13)
(12)
(11)
(10)
(9)
(bit 8)
undeÞned
Timer input capture 2 (TIC2) low
$0013
(bit 7)
(6)
(5)
(4)
(3)
(2)
(1)
(bit 0)
undeÞned
Timer input capture 3 (TIC3) high
$0014
(bit 15)
(14)
(13)
(12)
(11)
(10)
(9)
(bit 8)
undeÞned
Timer input capture 3 (TIC3) low
$0015
(bit 7)
(6)
(5)
(4)
(3)
(2)
(1)
(bit 0)
undeÞned
Timer output compare 1 (TOC1) high
$0016
(bit 15)
(14)
(13)
(12)
(11)
(10)
(9)
(bit 8) 1111 1111
Timer output compare 1 (TOC1) low
$0017
(bit 7)
(6)
(5)
(4)
(3)
(2)
(1)
(bit 0) 1111 1111
Timer output compare 2 (TOC2) high
$0018
(bit 15)
(14)
(13)
(12)
(11)
(10)
(9)
(bit 8) 1111 1111
Timer output compare 2 (TOC2) low
$0019
(bit 7)
(6)
(5)
(4)
(3)
(2)
(1)
(bit 0) 1111 1111
Timer output compare 3 (TOC3) high
$001A (bit 15)
(14)
(13)
(12)
(11)
(10)
(9)
(bit 8) 1111 1111
Timer output compare 3 (TOC3) low
$001B
(bit 7)
(6)
(5)
(4)
(3)
(2)
(1)
(bit 0) 1111 1111
Timer output compare 4 (TOC4) high
$001C (bit 15)
(14)
(13)
(12)
(11)
(10)
(9)
(bit 8) 1111 1111
Timer output compare 4 (TOC4) low
$001D
(bit 7)
(6)
(5)
(4)
(3)
(2)
(1)
(bit 0) 1111 1111
Capture 4/compare 5 (TI4/O5) high
$001E (bit 15)
(14)
(13)
(12)
(11)
(10)
(9)
(bit 8) 1111 1111
Capture 4/compare 5 (TI4/O5) low
$001F
(bit 7)
(6)
(5)
(4)
(3)
(2)
(1)
(bit 0) 1111 1111
Timer control 1 (TCTL1)
$0020
OM2
OL2
OM3
OL3
OM4
OL4
OM5
Timer control 2 (TCTL2)
$0021 EDG4B EDG4A EDG1B EDG1A EDG2B EDG2A EDG3B EDG3A 0000 0000
Timer interrupt mask 1 (TMSK1)
$0022
OC1I
OC2I
OC3I
OC4I
I4/O5I
IC1I
IC2I
OL5
IC3I
0000 0000
0000 0000
➡
TPG
MOTOROLA
3-6
OPERATING MODES AND ON-CHIP MEMORY
MC68HC11PH8
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Table 3-2 Register and control bit assignments (Sheet 2 of 4)
Register name
Address bit 7
bit 6
bit 5
bit 4
OC4F I4/O5F
Timer interrupt ßag 1 (TFLG1)
$0023
OC1F
OC2F
OC3F
Timer interrupt mask 2 (TMSK2)
$0024
TOI
RTII
PAOVI
PAII
RTIF PAOVF
PAIF
Timer interrupt ßag 2 (TFLG2)
$0025
TOF
Pulse accumulator control (PACTL)
$0026
0
Pulse accumulator count (PACNT)
$0027
(bit 7)
(6)
SPI control (SPCR)
$0028
SPIE
SPE
PAEN PAMOD PEDGE
(5)
(4)
bit 3
0
bit 2
bit 1
bit 0
State
on reset
IC1F
IC2F
IC3F
0000 0000
0
PR1
PR0
0000 0000
0
0000 0000
0
0
0
0
I4/O5
RTR1
(3)
(2)
(1)
DWOM MSTR CPOL CPHA SPR1
RTR0 0000 0000
(bit 0)
undeÞned
$0029
SPIF
WCOL
0
MODF
0
0
0
0
0000 0000
SPI data (SPDR)
$002A
(bit 7)
(6)
(5)
(4)
(3)
(2)
(1)
(bit 0)
undeÞned
EPROM programming (EPROG) à
$002B
MBE
0
0
0
EPGM 0000 0000
Port pull-up assignment (PPAR)
$002C
0
0
0
LCD control and data (LCDR)
$002D
LCD7
LCD6
LCD5
LCD4
0
0
$002E PLLON
BCS
AUTO
BWC
VCOT
MCS
PLL control (PLLCR)
HWOIF HPPUE GPPUE FPPUE BPPUE 0000 1111
LCDCK LCDE 0000 0000
T16EN WEN
Synthesizer program (SYNR)
$002F SYNX1 SYNX0 SYNY5 SYNY4 SYNY3 SYNY2 SYNY1 SYNY0 0000 1011
$0030
CCF
0
A/D result 1 (ADR1)
$0031
(bit 7)
(6)
(5)
A/D result 2 (ADR2)
$0032
(bit 7)
(6)
(5)
A/D result 3 (ADR3)
$0033
(bit 7)
(6)
A/D result 4 (ADR4)
$0034
(bit 7)
(6)
$0035 BULKP
0
Block protect (BPROT)
reserved
CD
CC
CB
CA
u0uu uuuu
(4)
(3)
(2)
(1)
(bit 0)
undeÞned
(4)
(3)
(2)
(1)
(bit 0)
undeÞned
(5)
(4)
(3)
(2)
(1)
(bit 0)
undeÞned
(5)
(4)
(3)
(2)
(1)
(bit 0)
undeÞned
BPRT4 PTCON BPRT3 BPRT2 BPRT1 BPRT0 1011 1111
$0036
EE3
EE2
EE1
EE0
STRX
0
EEPROM mapping (INIT2)
$0037
System conÞg. options 2 (OPT2)
$0038
LIRDV CWOM STRCH IRVNE LSBF
SPR2 EXT4X DISE
x00x 0000
System conÞg. options 1 (OPTION)
$0039
ADPU CSEL
COP timer arm/reset (COPRST)
$003A
(bit 7)
(6)
EEPROM programming (PPROG)
$003B
ODD
EVEN
Highest priority interrupt (HPRIO)
$003C RBOOT SMOD
DLY
CME
FCME
CR1
CR0
0001 0000
(5)
(4)
(3)
(2)
(1)
(bit 0)
undeÞned
0
BYTE
ROW ERASE EELAT EEPGM 0000 0000
PSEL4 PSEL3 PSEL2 PSEL1 PSEL0 xxx0 0110
RAM & I/O mapping (INIT)
$003D
RAM3 RAM2 RAM1 RAM0 REG3 REG2 REG1 REG0 0000 0000
Factory test (TEST1)
$003E
TILOP PLTST OCCR CBYP
ConÞguration control (CONFIG)
DISR
FCM
FCOP MIDLY 0000 0000
$003F ROMAD FREEZ CLK4X PAREN NOSEC NOCOP ROMON EEON xxxx xxxx
reserved
$0040
reserved
$0041
reserved
$0042
reserved
$0043
reserved
$0044
reserved
$0045
5
6
7
8
9
M2DL1 M2DL0 0000 0000
IRQE
MDA
4
x010 1010
A/D control & status (ADCTL)
SCAN MULT
3
SPR0 0000 01uu
SPI status (SPSR)
ELAT EXCOL EXROW
2
10
11
12
13
14
➡ 15
TPG
MC68HC11PH8
OPERATING MODES AND ON-CHIP MEMORY
MOTOROLA
3-7
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Table 3-2 Register and control bit assignments (Sheet 3 of 4)
2
Register name
Address bit 7
bit 6
bit 5
bit 4
bit 3
bit 2
bit 1
bit 0
State
on reset
reserved
$0046
reserved
$0047
reserved
$0048
reserved
$0049
reserved
$004A
reserved
$004B
5
SPI2 control (SP2CR)
$004C
SP2IE SP2E GWOM MSTR2 CPOL2 CPHA2 SP2R1 SP2R0 0000 01uu
SPI2 status (SP2SR)
$004D
SP2IF WCOL2
0
MODF2
SPI2 data (SP2DR)
$004E
(bit 7)
(6)
(5)
(4)
6
SPI2 control options (SP2OPT)
$004F
0
0
0
0
3
4
7
8
9
10
13
14
15
0
0
(3)
(2)
(1)
(bit 0)
undeÞned
0
0
0000 0000
LSBF2 SP2R2
0000 0000
$0050
B2TST B2SPL B2RST S2B12 S2B11 S2B10 S2B9
S2B8 0000 0000
SCI2/MI baud low (S2BDL)
$0051
S2B7
S2B1
S2B0 0000 0100
SCI2/MI control 1 (S2CR1)
$0052 LOPS2 WOMS2 MIE2
PE2
PT2
SCI2/MI control 2 (S2CR2)
$0053
SCI2/MI status 1 (S2SR1)
$0054 TDRE2
SCI2/MI status 2 (S2SR2)
$0055
SCI2/MI data high (S2DRH)
$0056
SCI2/MI data low (S2DRL)
$0057
reserved
$0058
8-bit modulus timer A data (T8ADR)
$0059
TIE2
S2B6
TCIE2
TC2
S2B5
RIE2
S2B4
M2
S2B3
S2B2
WAKE2 ILT2
ILIE2
TE2
RE2
RDRF2 IDLE2
0000 0000
RWU2 SBK2 0000 0000
OR2
NF2
FE2
0
0
0
0
0
0
0
R8B
T8B
0
0
0
0
0
PF2
1100 0000
RAF2 0000 0000
0
undeÞned
R7T7B R6T6B R5T5B R4T4B R3T3B R2T2B R1T1B R0T0B undeÞned
(bit 7)
(6)
(5)
(4)
(3)
(2)
(1)
(bit 0) 1111 1111
8-bit modulus timer B data (T8BDR)
$005A
(bit 7)
(6)
(5)
(4)
(3)
(2)
(1)
(bit 0)
undeÞned
8-bit modulus timer C data (T8CDR)
$005B
(bit 7)
(6)
(5)
(4)
(3)
(2)
(1)
(bit 0)
undeÞned
reserved
$005C
T8AI
T8AF
0
0
0
CSA2
CSA1
CSA0 0000 0000
8-bit modulus timer B control (T8BCR) $005E
T8BI
T8BF
0
0
PRB
CSB2
CSB1
CSB0 0000 0000
8-bit modulus timer C control (T8CCR) $005F
T8CI
T8CF
0
0
PRC
CSC2
CSC1
CSC0 0000 0000
Pulse width clock select (PWCLK)
12
0
SCI2/MI baud high (S2BDH)
8-bit modulus timer A control (T8ACR) $005D
11
0
$0060 CON34 CON12 PCKA2 PCKA1
0
PCKB3 PCKB2 PCKB1 0000 0000
Pulse width polarity select (PWPOL)
$0061
PCLK4 PCLK3 PCLK2 PCLK1 PPOL4 PPOL3 PPOL2 PPOL1 0000 0000
Pulse width scale (PWSCAL)
$0062
(bit 7)
(5)
(4)
Pulse width enable (PWEN)
$0063 TPWSL DISCP
0
0
Pulse width count 1 (PWCNT1)
$0064
(bit 7)
(6)
(5)
(4)
(3)
(2)
(1)
(bit 0) 0000 0000
Pulse width count 2 (PWCNT2)
$0065
(bit 7)
(6)
(5)
(4)
(3)
(2)
(1)
(bit 0) 0000 0000
Pulse width count 3 (PWCNT3)
$0066
(bit 7)
(6)
(5)
(4)
(3)
(2)
(1)
(bit 0) 0000 0000
Pulse width count 4 (PWCNT4)
$0067
(bit 7)
(6)
(5)
(4)
(3)
(2)
(1)
(bit 0) 0000 0000
Pulse width period 1 (PWPER1)
$0068
(bit 7)
(6)
(5)
(4)
(3)
(2)
(1)
(bit 0) 1111 1111
(6)
(3)
(2)
(1)
(bit 0) 0000 0000
PWEN4 PWEN3 PWEN2 PWEN1 0000 0000
➡
TPG
MOTOROLA
3-8
OPERATING MODES AND ON-CHIP MEMORY
MC68HC11PH8
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1
Table 3-2 Register and control bit assignments (Sheet 4 of 4)
Register name
Address bit 7
bit 6
bit 5
bit 4
bit 3
bit 2
bit 1
bit 0
State
on reset
Pulse width period 2 (PWPER2)
$0069
(bit 7)
(6)
(5)
(4)
(3)
(2)
(1)
(bit 0) 1111 1111
Pulse width period 3 (PWPER3)
$006A
(bit 7)
(6)
(5)
(4)
(3)
(2)
(1)
(bit 0) 1111 1111
Pulse width period 4 (PWPER4)
$006B
(bit 7)
(6)
(5)
(4)
(3)
(2)
(1)
(bit 0) 1111 1111
Pulse width duty 1 (PWDTY1)
$006C
(bit 7)
(6)
(5)
(4)
(3)
(2)
(1)
(bit 0) 1111 1111
Pulse width duty 2 (PWDTY2)
$006D
(bit 7)
(6)
(5)
(4)
(3)
(2)
(1)
(bit 0) 1111 1111
Pulse width duty 3 (PWDTY3)
$006E
(bit 7)
(6)
(5)
(4)
(3)
(2)
(1)
(bit 0) 1111 1111
(5)
(4)
(3)
(2)
(1)
Pulse width duty 4 (PWDTY4)
$006F
(bit 7)
(6)
SCI1 baud rate high (SCBDH)
$0070
BTST
BSPL
BRST SBR12 SBR11 SBR10 SBR9
SBR8 0000 0000
(bit 0) 1111 1111
SCI1 baud rate low (SCBDL)
$0071
SBR7
SBR6
SBR5
SBR4
SBR3
SBR2
SBR1
SBR0 0000 0100
0
M
WAKE
ILT
PE
PT
0000 0000
SCI1 control 1 (SCCR1)
$0072 LOOPS WOMS
SCI1 control 2 (SCCR2)
$0073
TIE
TCIE
RIE
ILIE
TE
RE
RWU
SBK
0000 0000
SCI1 status 1 (SCSR1)
$0074
TDRE
TC
RDRF
IDLE
OR
NF
FE
PF
1100 0000
SCI1 status 2 (SCSR2)
$0075
0
0
0
0
0
0
0
RAF
0000 0000
SCI1 data high (SCDRH)
$0076
R8
T8
0
0
0
0
0
0
undeÞned
SCI1 data low (SCDRL)
$0077
R7T7
R6T6
R5T5
R4T4
R3T3
R2T2
R1T1
R0T0
undeÞned
reserved
$0078
reserved
$0079
reserved
$007A
2
3
4
5
6
7
8
Wired-OR interrupt enable (WOIEH)
$007B
IEH7
IEH6
IEH5
IEH4
IEH3
IEH2
IEH1
IEH0
0000 0000
Port H data (PORTH)
$007C
PH7
PH6
PH5
PH4
PH3
PH2
PH1
PH0
undeÞned
Data direction H (DDRH)
$007D
DDH7 DDH6 DDH5 DDH4 DDH3 DDH2 DDH1 DDH0 0000 0000
Port G data (PORTG)
$007E
PG7
Data direction G (DDRG)
$007F
PG6
PG5
PG4
PG3
PG2
PG1
PG0
undeÞned
DDG7 DDG6 DDG5 DDG4 DDG3 DDG2 DDG1 DDG0 0000 0000
KEY
à Applies only to EPROM devices
x State on reset depends on mode selected
u State of bit on reset is undeÞned
9
10
11
12
13
14
➡ 15
TPG
MC68HC11PH8
OPERATING MODES AND ON-CHIP MEMORY
MOTOROLA
3-9
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3.3
2
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PH8.DS03/Modes+mem
System initialization
Registers and bits that control initialization and the basic operation of the MCU are protected
against writes except under special circumstances. The following table lists registers that can be
written only once after reset, or that must be written within the first 64 cycles after reset.
3
Table 3-3 Registers with limited write access
4
Register
address
$x024
$x02D
$x035
$x037
$x038
$x039
$x03D
5
6
Register
Must be written in
Write
name
Þrst 64 cycles
once only
(1)
Timer interrupt mask register 2 (TMSK2)
Ñ
(2)
LCD control and data register (LCDR)
No
(3)
Block protect register (BPROT)
Ñ
EEPROM mapping register (INIT2)
No
Yes
(4)
System conÞguration options register 2 (OPT2)
No
(5)
System conÞguration options register (OPTION)
Ñ
(6)
RAM and I/O map register (INIT)
Ñ
(1) When SMOD = 0, bits 1 and 0 can be written only once, during the Þrst 64 cycles, after
which they become read-only. When SMOD = 1, however, these bits can be written at any
time. All other bits can be written at any time.
7
(2) Bit 0 (LCDE) can be written only once.
(3) Bits can be written to zero once and only in the Þrst 64 cycles or in special modes. Bits can
be set to one at any time.
8
(4) Bit 0 (DISE) and bit 1 (EXT4X) can be written only once; bit 4 (IRVNE) can be written only
once in single chip and user expanded modes.
9
(5) Bits 5, 4, 2, 1, and 0 can be written once and only in the Þrst 64 cycles; when SMOD = 1,
however, bits 5, 4, 2, 1, and 0 can be written at any time. All other bits can be written at any time.
(6) When SMOD = 0, bits can be written only once, during the Þrst 64 cycles, after which the
register becomes read-only. When SMOD = 1, bits can be written at any time.
10
11
12
13
14
15
3.3.1
Mode selection
The four mode variations are selected by the logic states of the mode A (MODA) and mode B
(MODB) pins during reset. The MODA and MODB logic levels determine the logic state of special
mode (SMOD) and the mode A (MDA) control bits in the highest priority I-bit interrupt and
miscellaneous (HPRIO) register.
After reset is released, the mode select pins no longer influence the MCU operating mode. In
single chip operating mode, MODA pin is connected to a logic zero. In expanded mode, MODA is
normally connected to VDD through a pull-up resistor of 4.7 kΩ. The MODA pin also functions as
the load instruction register (LIR) pin when the MCU is not in reset. The open-drain active low LIR
output pin drives low during the first E cycle of each instruction, if enabled by the LIRDV bit in the
OPT2 register. The MODB pin also functions as the stand-by power input (VSTBY), which allows
the RAM contents to be maintained in the absence of VDD.
➡
TPG
MOTOROLA
3-10
OPERATING MODES AND ON-CHIP MEMORY
MC68HC11PH8
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Refer to Table 3-4, which is a summary of mode pin operation, the mode control bits and the four
operating modes.
A normal mode is selected when MODB is logic one during reset. One of three reset vectors is
fetched from address $FFFA–$FFFF, and program execution begins from the address indicated
by this vector. If MODB is logic zero during reset, the special mode reset vector is fetched from
addresses $BFFA–$BFFF and software has access to special test features. Refer to Section 10.
3.3.1.1
HPRIO — Highest priority I-bit interrupt & misc. register
Address
Highest priority interrupt (HPRIO)
Note:
bit 7
bit 6
$003C RBOOT SMOD
bit 5
MDA
bit 4
bit 3
bit 2
bit 1
bit 0
State
on reset
PSEL4 PSEL3 PSEL2 PSEL1 PSEL0 xxx0 0110
RBOOT, SMOD and MDA bits depend on the power-up initialization mode and can only
be written in special modes when SMOD = 1. Refer to Table 3-4.
RBOOT — Read bootstrap ROM
1 (set)
–
0 (clear) –
Bootloader ROM disabled and not in map.
–
Special mode variation in effect.
0 (clear) –
Normal mode variation in effect.
2
3
4
5
6
7
Bootloader ROM enabled, at $BE40–$BFFF.
8
SMOD — Special mode select
1 (set)
1
9
Once cleared, cannot be set again.
10
MDA — Mode select A
1 (set)
–
0 (clear) –
Normal expanded or special test mode. (Expanded buses active.)
11
Normal single chip or special bootstrap mode. (Ports active.)
Table 3-4 Hardware mode select summary
Inputs
MODB MODA
1
0
1
1
0
0
0
1
12
Control bits in HPRIO (latched at reset)
RBOOT
SMOD
MDA
Single chip
0
0
0
Expanded
0
0
1
Special bootstrap
1
1
0
Special test
0
1
1
Mode
13
14
PSEL[4:0] — Priority select bits (refer to Section 10)
➡ 15
TPG
MC68HC11PH8
OPERATING MODES AND ON-CHIP MEMORY
MOTOROLA
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3.3.2
2
3
4
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Initialization
Because bits in the following registers control the basic configuration of the MCU, an accidental
change of their values could cause serious system problems. The protection mechanism,
overridden in special operating modes, requires a write to the protected bits only within the first 64
bus cycles after any reset, or only once after each reset. See Table 3-3.
3.3.2.1
CONFIG — System configuration register
Address
5
6
7
PH8.DS03/Modes+mem
ConÞguration control (CONFIG)
bit 7
bit 6
bit 5
bit 4
bit 3
bit 2
bit 1
bit 0
State
on reset
$003F ROMAD FREEZ CLK4X PAREN NOSEC NOCOP ROMON EEON xxxx xxxx
CONFIG controls the presence and/or location of ROM/EPROM and EEPROM in the memory
map and enables the COP watchdog system.The FREEZ bit provides a method of reducing RFI
emissions in expanded mode, the CLK4X bit enables the 4XOUT pin to output either 4XCLK or
the internal EXTAL signal (EXTALi), and the PAREN bit enables pull-ups on certain ports. A
security feature that protects data in EEPROM and RAM is available, controlled by the NOSEC
bit. Refer to Section 3.4.4.
8
CONFIG is made up of EEPROM cells and static working latches. The operation of the MCU is
controlled directly by these latches and not the EEPROM byte. When programming the CONFIG
register, the EEPROM byte is accessed. When the CONFIG register is read, the static latches are
accessed.
9
These bits can be read at any time. The value read is the one latched into the register from the
EEPROM cells during the last reset sequence. A new value programmed into this register is not
readable until after a subsequent reset sequence.
10
On the MC68HC711PH8, and on the MC68HC11PH8 if selected by a mask option, the ROMON
bit can be written at any time if MDA = 1 (expanded mode or special test mode). It cannot be
written in bootstrap mode, and is forced to a logic one in single chip mode.
11
Other bits in CONFIG can be written at any time if SMOD = 1 (bootstrap or special test mode). If
SMOD = 0 (single chip or expanded mode), these bits can only be written using the EEPROM
programming sequence, and none of the bits are readable or active until latched via the next reset.
12
FREEZ is only active in expanded user mode.
ROMAD — ROM mapping control
13
14
15
1 (set)
–
0 (clear) –
ROM/EPROM addressed from $4000 to $FFFF.
ROM/EPROM addressed from $0000 to $BFFF (expanded mode
only).
In single chip mode, reset sets this bit.
➡
TPG
MOTOROLA
3-12
OPERATING MODES AND ON-CHIP MEMORY
MC68HC11PH8
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1
FREEZ — Address bus freeze in expanded user mode
1 (set)
–
0 (clear) –
2
The external bus is only active when externally mapped resources
are accessed (expanded mode only).
Normal operation.
To reduce RFI emissions, the address bus (on ports B and F) is not active while internal resources
are being accessed, but will instead freeze on the last external address. At this time, the data bus
port C is three-stated (high impedance) with weak pull-ups active, R/W is forced high and the E
clock enable is pulled low. At reset, the address bus is initialized to $FFFE. Refer to Figure 3-2.
3
4
5
Internal E
IMMP
(internal
signal)
Internal
External
Internal
6
E
7
ADDR
(Resistive pull-up)
DATA
In
8
Out
R/W
9
Figure 3-2 Example of expanded mode FREEZ actions
10
CLK4X — 4X clock enable
1 (set)
–
0 (clear) –
Note:
11
4XCLK or EXTALi driven out on the 4XOUT pin (see Section 3.3.2.5)
4XOUT pin disabled.
12
The 4XOUT pin is not available on 84-pin packaged devices.
13
PAREN — Pull-up assignment register enable (refer to Section 4)
1 (set)
–
0 (clear) –
Pull-ups can be enabled using PPAR.
14
All pull-ups disabled (not controlled by PPAR).
➡ 15
TPG
MC68HC11PH8
OPERATING MODES AND ON-CHIP MEMORY
MOTOROLA
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NOSEC — EEPROM security disabled (refer to Section 3.4.4)
2
3
4
1 (set)
–
Disable security.
0 (clear) –
Enable security.
NOCOP — COP system disable (refer to Section 10)
1 (set)
–
0 (clear) –
COP system disabled.
COP system enabled (forces reset on timeout).
ROMON — ROM enable
5
6
7
8
1 (set)
–
0 (clear) –
ROM/EPROM excluded from the memory map.
In single chip mode, reset sets this bit. In special test mode, reset clears ROMON. On the
MC68HC711PH8, and on the MC68HC11PH8 if selected by a mask option, ROMON can be
modified in expanded and special test modes. In this case, care must be taken to include reset
and interrupt vectors in both internal and external memory maps. The routines for altering
ROMON should not be located at addresses in the internal ROM/EPROM memory range, but
rather at different external ROM/EPROM addresses or in internal EEPROM.
EEON — EEPROM enable
1 (set)
–
0 (clear) –
9
ROM/EPROM included in the memory map.
3.3.2.2
EEPROM included in the memory map.
EEPROM is excluded from the memory map.
INIT — RAM and I/O mapping register
10
Address
RAM & I/O mapping (INIT)
11
12
13
14
15
$003D
bit 7
bit 6
bit 5
bit 4
bit 3
bit 2
bit 1
bit 0
State
on reset
RAM3 RAM2 RAM1 RAM0 REG3 REG2 REG1 REG0 0000 0000
The internal registers used to control the operation of the MCU can be relocated on 4K boundaries
within the memory space with the use of INIT. This 8-bit special-purpose register can change the
default locations of the RAM and control registers within the MCU memory map. It can be written
to only once within the first 64 E clock cycles after a reset. It then becomes a read-only register.
RAM[3:0] — RAM map position
These four bits, which specify the upper hexadecimal digit of the RAM address, control the
position of the RAM in the memory map. The RAM can be positioned at the beginning of any 4K
page in the memory map. Refer to Table 3-5.
➡
TPG
MOTOROLA
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1
These four bits specify the upper hexadecimal digit of the address for the 128-byte block of internal
registers. The register block is positioned at the beginning of any 4K page in the memory map.
Refer to Table 3-5.
2
REG[3:0] — 128-byte register block position
3
Table 3-5 RAM and register remapping
RAM[3:0]
0000
0001
0010
0011
0100
0101
0110
0111
1000
1001
1010
1011
1100
1101
1110
1111
Location
$0000Ð$07FF
$1000Ð$17FF
$2000Ð$27FF
$3000Ð$37FF
$4000Ð$47FF
$5000Ð$57FF
$6000Ð$67FF
$7000Ð$77FF
$8000Ð$87FF
$9000Ð$97FF
$A000Ð$A7FF
$B000Ð$B7FF
$C000Ð$C7FF
$D000Ð$D7FF
$E000Ð$E7FF
$F000Ð$F7FF
REG[3:0]
0000
0001
0010
0011
0100
0101
0110
0111
1000
1001
1010
1011
1100
1101
1110
1111
Location
$0000Ð$007F
$1000Ð$107F
$2000Ð$207F
$3000Ð$307F
$4000Ð$407F
$5000Ð$507F
$6000Ð$607F
$7000Ð$707F
$8000Ð$807F
$9000Ð$907F
$A000Ð$A07F
$B000Ð$B07F
$C000Ð$C07F
$D000Ð$D07F
$E000Ð$E07F
$F000Ð$F07F
4
5
6
7
8
When the memory map has the 128-byte register block mapped at the same location as RAM, the
registers have priority and the RAM is relocated to the memory space immediately following the
register block. This mapping feature keeps all the RAM available for use. Refer to Figure 3-3, which
illustrates the overlap.
$x000
$x07F
$x080
RAM A
$x000
$x07F
$x080
RAM B
$x7FF
$x7FF
$x800
$x87F
Register and RAM mapped
to different 4K boundaries.
9
10
Register block
11
RAM B
12
13
RAM A
Register and RAM mapped
to the same 4K boundary.
14
Figure 3-3 RAM and register overlap
➡ 15
TPG
MC68HC11PH8
OPERATING MODES AND ON-CHIP MEMORY
MOTOROLA
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3.3.2.3
4
PH8.DS03/Modes+mem
INIT2 — EEPROM mapping and MI BUS delay register
2
3
—this line does not form part of the document—
EEPROM mapping (INIT2)
Address
bit 7
bit 6
bit 5
bit 4
bit 3
bit 2
$0037
EE3
EE2
EE1
EE0
STRX
0
bit 1
bit 0
State
on reset
M2DL1 M2DL0 0000 0000
This register determines the location of EEPROM in the memory map and controls stretching of
external accesses. INIT2 may be read at any time but bits 7–4 may be written only once after reset
in normal modes (bits 3, 1 and 0 may be written at any time).
EE[3:0] — EEPROM map position
5
EEPROM is located at $xD00–$xFFF, where x is the hexadecimal digit represented by EE[3:0].
Refer to Table 3-6.
6
Table 3-6 EEPROM remapping
EE[3:0]
0000
0001
0010
0011
0100
0101
0110
0111
7
8
9
Location
$0D00Ð$0FFF
$1D00Ð$1FFF
$2D00Ð$2FFF
$3D00Ð$3FFF
$4D00Ð$4FFF
$5D00Ð$5FFF
$6D00Ð$6FFF
$7D00Ð$7FFF
EE[3:0]
1000
1001
1010
1011
1100
1101
1110
1111
Location
$8D00Ð$8FFF
$9D00Ð$9FFF
$AD00Ð$AFFF
$BD00Ð$BFFF
$CD00Ð$CFFF
$DD00Ð$DFFF
$ED00Ð$EFFF
$FD00Ð$FFFF
STRX — Stretch extended†
10
1 (set)
–
0 (clear) –
11
12
All external accesses are extended by one E clock cycle.
Only external access from $0000 to $1FFF (ROMAD set) or from
$C000 to $DFFF (ROMAD clear) are extended by one E clock cycle.
This bit only has meaning in expanded mode, and only if the STRCH bit in OPT2 is set (see
Section 3.3.2.5).
Bit 2 — Not implemented; always reads zero.
M2DL1, M2DL0 — MI BUS delay select (refer to Section 6)
13
†
14
15
This bit is not present on early versions of the MC68HC711PH8. On those devices, bit 3 is not
implemented and always reads zero, and the stretch function is controlled solely by the
STRCH bit in OPT2 (see Section 3.3.2.5). Contact your local Motorola Sales Representative
for further information.
➡
TPG
MOTOROLA
3-16
OPERATING MODES AND ON-CHIP MEMORY
MC68HC11PH8
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1
OPTION — System configuration options register 1
Address
System conÞg. options 1 (OPTION)
$0039
bit 6
bit 5
bit 4
bit 3
bit 2
bit 1
bit 0
State
on reset
ADPU CSEL
IRQE
DLY
CME
FCME
CR1
CR0
0001 0000
bit 7
The 8-bit special-purpose OPTION register sets internal system configuration options during
initialization. The time protected control bits IRQE, DLY, FCME and CR[1:0] can be written only
once in the first 64 cycles after a reset and then they become read-only bits. This minimizes the
possibility of any accidental changes to the system configuration. They may be written at any time
in special modes.
–
0 (clear) –
6
A/D system disabled, to reduce supply current.
7
CSEL — Clock select (refer to Section 9)
–
0 (clear) –
4
A/D system power enabled.
After enabling the A/D power, at least 100µs should be allowed for system stabilization.
1 (set)
3
5
ADPU — A/D power-up (refer to Section 9)
1 (set)
2
A/D, EPROM and EEPROM use internal RC clock source (about
1.5MHz).
8
A/D, EPROM and EEPROM use system E clock
(must be at least 1MHz).
This bit selects the clock source for the on-chip EPROM, EEPROM and A/D charge pumps. The
on-chip RC clock should be used when the E clock frequency falls below 1MHz.
9
IRQE — Configure IRQ for falling edge sensitive operation
1 (set)
–
0 (clear) –
10
Falling edge sensitive operation.
Low level sensitive operation.
11
DLY — Enable oscillator start-up delay
1 (set)
–
A stabilization delay is imposed as the MCU is started up from STOP
mode (or from power-on reset).
0 (clear) –
The oscillator start-up delay is bypassed and the MCU resumes
processing within about four bus cycles. A stable external oscillator
is required if this option is selected.
12
DLY is set on reset, so a delay is always imposed as the MCU is started up from power-on reset.
13
A mask option on the MC68HC11PH8 allows the selection of either a short or long delay time for
power-on reset and exit from STOP mode; either 128 or 4064 bus cycles. This option is not
available on the MC68HC711PH8 where the delay time is 4064 bus cycles.
14
➡ 15
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MC68HC11PH8
OPERATING MODES AND ON-CHIP MEMORY
MOTOROLA
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CME — Clock monitor enable (refer to Section 10)
2
3
4
1 (set)
–
Clock monitor enabled.
0 (clear) –
Clock monitor disabled.
In order to use both STOP and clock monitor, the CME bit should be set before executing STOP,
then set again after recovering from STOP.
FCME — Force clock monitor enable (refer to Section 10)
1 (set)
–
0 (clear) –
5
6
7
8
9
10
11
12
13
Clock monitor enabled; cannot be disabled until next reset.
Clock monitor follows the state of the CME bit.
When FCME is set, slow or stopped clocks will cause a clock failure reset sequence. To utilize
STOP mode, FCME should always be cleared.
CR[1:0] — COP timer rate select bits (refer to Section 10)
These control bits determine a scaling factor for the watchdog timer.
3.3.2.5
OPT2 — System configuration options register 2
Address
System conÞg. options 2 (OPT2)
$0038
bit 7
bit 6
bit 5
bit 4
bit 3
LIRDV CWOM STRCH IRVNE LSBF
bit 2
bit 1
bit 0
State
on reset
SPR2 EXT4X DISE x00x 000t0
LIRDV — LIR driven
1 (set)
–
0 (clear) –
Enable LIR push-pull drive.
LIR not driven on MODA/LIR pin.
This bit allows power savings in expanded modes by turning off the LIR output (it has no meaning
in single chip or bootstrap modes). The LIR pin is driven low to indicate that execution of an
instruction has begun. In order to detect consecutive instructions in a high speed application, this
signal drives high for a quarter of a cycle to prevent false triggering. An external pull-up is required
in expanded modes, while a hardwired VSS connection is possible in single chip modes. LIRDV
is reset to zero in single chip modes, and to one in expanded modes.
CWOM — Port C wired-OR mode (refer to Section 4)
1 (set)
–
0 (clear) –
Port C outputs are open-drain.
Port C operates normally.
14
15
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MOTOROLA
3-18
OPERATING MODES AND ON-CHIP MEMORY
MC68HC11PH8
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1
STRCH — Stretch external accesses
1 (set)
–
0 (clear) –
2
Off-chip accesses are selectively extended by one E clock cycle.
Normal operation.
When this bit is set, off-chip accesses of selected addresses are extended by one E clock cycle
to allow access to slow peripherals. The E clock stretches externally, but the internal clocks are
not affected, so that timers and serial systems are not corrupted. The state of the STRX† bit (in
the INIT2 register) and the ROMAD bit (in the CONFIG register) determines which address range
is affected. See Section 3.3.2.3.
Note:
STRCH is cleared on reset; therefore a program cannot execute out of reset in a slow
external ROM.
To use this feature, ROMON must be set on reset so that the device starts with internal ROM
included in the memory map. STRCH should then be set.
Setting STRX means that all external accesses are stretched. If required (and allowed), ROMON
can then be cleared so that internal ROM is not present in the memory map (see Section 3.4.3).
If STRX is cleared, then external accesses from $0000 to $1FFF (ROMAD set) or from $C000 to
$DFFF (ROMAD cleared) are stretched.
STRCH has no effect in single chip and boot modes.
3
4
5
6
7
8
IRVNE — Internal read visibility/not E
IRVNE can be written once in any user mode. In expanded modes, IRVNE determines whether
IRV is on or off (but has no meaning in user expanded secure mode, as IRV must be disabled). In
special test mode, IRVNE is reset to one. In normal modes, IRVNE is reset to zero.
1 (set)
–
0 (clear) –
10
Data from internal reads is driven out of the external data bus.
No visibility of internal reads on external bus.
In single chip modes this bit determines whether the E clock drives out from the chip.
1 (set)
–
0 (clear) –
9
11
E pin is driven low.
E clock is driven out from the chip.
12
Refer to the following table for a summary of the operation immediately following reset.
13
†
The STRX bit is not present on early versions of the MC68HC711PH8; on those devices,
setting STRCH means that external accesses either from $0000 to $FFFF or from $C000 to
$DFFF are stretched, depending on the state of ROMAD. Contact your local Motorola Sales
Representative for further information.
14
➡ 15
TPG
MC68HC11PH8
OPERATING MODES AND ON-CHIP MEMORY
MOTOROLA
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IRVNE
E clock
IRV
IRVNE
IRVNE
after reset after reset after reset affects only can be written
Single chip
0
On
Off
E
Once
Expanded
0
On
Off
IRV
Once
Boot
0
On
Off
E
Unlimited
Special test
1
On
On
IRV
Unlimited
Mode
2
3
LSBF — LSB-first enable (refer to Section 7)
4
5
1 (set)
–
Data is transferred LSB first.
0 (clear) –
Data is transferred MSB first.
SPR2 — SPI clock rate select (refer to Section 7)
This bit adds a divide-by-four to the SPI clock chain.
6
EXT4X — 4XLCK or EXTAL clock output select
This bit can be written once and can be read at any time.
7
8
9
10
11
12
1 (set)
–
EXTALi clock output on the 4XOUT pin.
0 (clear) –
4XCLK clock output on the 4XOUT pin.
This bit selects which clock is to be output on the 4XOUT pin, when enabled by the CLK4X bit in
CONFIG (see Section 3.3.2.1). On reset, or when BCS = 0, 4XCLK (the PLL output) is the same
as EXTALi. Refer to Section 2-6. There is a phase delay between EXTALi and 4XOUT.
Note:
The 4XOUT pin is not available on 84-pin packaged devices.
DISE — E clock output disable
This bit can be written once and can be read at any time.
1 (set)
–
0 (clear) –
No E clock output.
E clock is output normally.
IRVNE allows E clock to be turned off in single chip modes. DISE has been added for expanded
modes, but can be used in every mode. Writing a zero to this bit prevents accidental E clock
turn-off in systems requiring this signal.
13
14
15
➡
TPG
MOTOROLA
3-20
OPERATING MODES AND ON-CHIP MEMORY
MC68HC11PH8
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1
BPROT — Block protect register
Address
Block protect (BPROT)
bit 7
bit 6
$0035 BULKP
0
bit 5
bit 4
bit 3
bit 2
bit 1
bit 0
State
on reset
BPRT4 PTCON BPRT3 BPRT2 BPRT1 BPRT0 1011 1111
BPROT prevents accidental writes to EEPROM and the CONFIG register. The bits in this register
can be written to zero only once during the first 64 E clock cycles after reset in the normal modes;
they can be set at any time. Once the bits are cleared, the EEPROM array and the CONFIG
register can be programmed or erased. Setting the bits in the BPROT register to logic one protects
the EEPROM and CONFIG register until the next reset. Refer to Table 3-7.
–
0 (clear) –
3
4
5
BULKP — Bulk erase of EEPROM protect
1 (set)
2
EEPROM cannot be bulk or row erased.
6
EEPROM can be bulk erased normally.
Bit 6 — Not implemented; always reads zero.
7
BPRT4 — Block protect bit for top 256 bytes of EEPROM (see below)
PTCON — Protect for CONFIG register
1 (set)
–
0 (clear) –
8
CONFIG register cannot be programmed or erased.
CONFIG register can be programmed or erased normally.
9
Note that, in special modes, CONFIG may be written regardless of the state of PTCON.
BPRT[4:0] — Block protect bits for EEPROM
1 (set)
–
0 (clear) –
10
Protection is enabled for associated block; it cannot be programmed
or erased.
Protection disabled for associated block.
11
Each of these five bits protects a block of EEPROM against writing or erasure, as follows:
12
Table 3-7 EEPROM block protect
Bit name
BPRT0
BPRT1
BPRT2
BPRT3
BPRT4
Block protected
$xD00Ð$xD1F
$xD20Ð$xD5F
$xD60Ð$xDDF
$xDE0Ð$xEFF
$xF00Ð$xFFF
Block size
32 bytes
64 bytes
128 bytes
288 bytes
256 bytes
13
14
➡ 15
TPG
MC68HC11PH8
OPERATING MODES AND ON-CHIP MEMORY
MOTOROLA
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3.3.2.7
Timer interrupt mask 2 (TMSK2)
Address
bit 7
bit 6
bit 5
bit 4
bit 3
bit 2
bit 1
bit 0
State
on reset
$0024
TOI
RTII
PAOVI
PAII
0
0
PR1
PR0
0000 0000
PR[1:0] are time-protected control bits and can be changed only once and then only within the first
64 bus cycles after reset in normal modes.
4
Note:
5
TOI — Timer overflow interrupt enable (Refer to Section 8)
Bits in TMSK2 correspond bit for bit with flag bits in TFLG2. Ones in TMSK2 enable the
corresponding interrupt sources.
1 (set)
6
PH8.DS03/Modes+mem
TMSK2 — Timer interrupt mask register 2
2
3
—this line does not form part of the document—
–
0 (clear) –
Interrupt requested when TOF is set.
TOF interrupts disabled.
RTII — Real-time interrupt enable (Refer to Section 8)
7
1 (set)
–
0 (clear) –
8
RTIF interrupts disabled.
PAOVI — Pulse accumulator overflow interrupt enable (Refer to Section 8)
1 (set)
9
Interrupt requested when RTIF set.
–
0 (clear) –
Interrupt requested when PAOVF set.
PAOVF interrupts disabled.
PAII — Pulse accumulator interrupt enable (Refer to Section 8)
10
1 (set)
–
0 (clear) –
11
Interrupt requested when PAIF set.
PAIF interrupts disabled.
Bits [3, 2] — Not implemented; always read zero.
PR[1:0] — Timer prescaler select
12
These two bits select the prescale rate for the main 16-bit free-running timer system. These bits
can be written only once during the first 64 E clock cycles after reset in normal modes, or at any
time in special modes. Refer to the following table:
13
PR[1:0] Prescale factor
00
1
01
4
10
8
11
16
14
15
➡
TPG
MOTOROLA
3-22
OPERATING MODES AND ON-CHIP MEMORY
MC68HC11PH8
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1
EPROM, EEPROM and CONFIG register
3.4
2
3.4.1
EPROM
Using the on-chip EPROM programming feature requires an external power supply (VPPE). Normal
programming is accomplished using the EPROG register. Program EPROM at room temperature
only and place an opaque label over the quartz window during and after programming.
The CSEL bit in the OPTION register selects an on-chip oscillator clock for programming the
EPROM while operating at frequencies below 1MHz.
The erased state of each EPROM byte is $FF.
3.4.1.1
3
4
5
EPROG — EPROM programming control register
EPROM programming (EPROG)
Address
bit 7
bit 6
$002B
MBE
0
bit 5
bit 4
bit 3
ELAT EXCOL EXROW
bit 2
bit 1
0
0
bit 0
State
on reset
EPGM 0000 0000
MBE — Multiple byte program enable
This bit may be read or written only in special modes; it will always read zero in normal modes.
1 (set)
–
0 (clear) –
Program 12 bytes with the same data.
Normal programming.
EPROM is made up of three blocks of 16K bytes. When programming, address bits 4 and 7 are
ignored, so that 4 addresses per block are programmed simultaneously. Address bits 14 and 15
are also ignored so that a total of twelve addresses are written at once, four in each 16K byte block.
For example, with the EPROM mapped to $4000–$FFF, a write to $4026 will actually program
$4026, $4036, $40A6, $40B6, $8026, $8036, $80A6, $80B6, $C026, $C036. $C0A6 and $C0B6
(i.e. %xx00 0000 x01x 0110).
6
7
8
9
10
11
Bits [6, 2, 1] — Not implemented; always read zero.
ELAT — EPROM latch control
12
ELAT may be read and written at any time.
1 (set)
–
0 (clear) –
EPROM address and data buses configured for programming.
EPROM cannot be read.
13
EPROM address and data buses configured for normal operation.
When set, this bit causes the address and data for writes to the EPROM to be latched.
14
➡ 15
TPG
MC68HC11PH8
OPERATING MODES AND ON-CHIP MEMORY
MOTOROLA
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EXCOL — Select extra columns
2
The EXCOL bit always reads zero in normal modes and may be read or written only in special
modes.
1 (set)
3
–
0 (clear) –
User array disabled; extra column selected.
User array selected.
The extra column may be accessed at bit 7; addresses use bits 15–5, bits 4–0 must be ones.
4
EXROW — Select extra rows
This bit always reads zero in normal modes and may be read or written only in special modes.
5
1 (set)
–
0 (clear) –
6
7
EPGM — EPROM program command
This bit can be read at any time, but may only be written if ELAT is set.
8
11
Note:
13
14
15
Programming voltage (VPPE) switched to the EPROM array.
Programming voltage (VPPE) disconnected from the EPROM array.
If ELAT = 0 (normal operation) then EPGM = 0 (programming voltage disconnected).
EPROM programming
The EPROM may be programmed and verified in software, via the MCU, using the following
procedure. The ROMON bit in the CONFIG register should be set. To use this method in special
bootstrap mode, the external EPROM programming voltage must be applied on pin VPPE. On
entry, A contains the data to be programmed and X contains the EPROM address.
EPROG
12
–
0 (clear) –
3.4.1.2
10
User array selected.
There are six extra rows (two in each block). Addresses use bits 6–0, bits 11–7 must be zeros.
(The high nibble determines which 16K block is accessed.)
1 (set)
9
User array disabled; extra rows selected.
LDAB
STAB
STAA
LDAB
STAB
JSR
CLR
#$20
$002B
$0, X
#$21
$002B
DLYEP
$002B
Set ELAT bit (PGM=0) to enable EPROM latches.
Store data to EPROM address
Set EPGM bit, with ELAT=1, to enable prog. voltage
Delay tEPROG
Turn off programming voltage and set to READ mode
User-developed software can be uploaded through the SCI, or an EPROM programming utility
resident in the bootstrap ROM can be used. To use the resident utility, bootload a three-byte
program into RAM consisting of a single jump instruction to $BF00 (the starting address of a
➡
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MOTOROLA
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OPERATING MODES AND ON-CHIP MEMORY
MC68HC11PH8
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resident EPROM programming utility), along with instructions to set the X and Y index registers to
default values. The utility program receives programming data from an external host and puts it in
EPROM. The value in IX determines programming delay time; for example, at 4 MHz operation, a
delay constant of 8000 in IX will give a 2ms delay time. The value in IY is a pointer to the first
address in EPROM to be programmed (normally = $4000). When the utility program is ready to
receive programming data, it sends the host an $FF character; then it waits. When the host sees
the $FF character, the EPROM programming data is sent, starting with location $4000. After the
last byte to be programmed is sent and the corresponding verification data is returned, the
programming operation is terminated by resetting the MCU.
3.4.2
EEPROM
The 768-byte on-board EEPROM is initially located from $0D00 to $0FFF after reset in all modes. It
can be mapped to any other 4K page by writing to the INIT2 register. The EEPROM is enabled by the
EEON bit in the CONFIG register. Programming and erasing are controlled by the PPROG register.
Unlike information stored in ROM, data in the 768 bytes of EEPROM can be erased and
reprogrammed under software control. Because programming and erasing operations use an
on-chip charge pump driven by VDD, a separate external power supply is not required.
An internal charge pump supplies the programming voltage. Use of the block protect register
(BPROT) prevents inadvertent writes to (or erases of) blocks of EEPROM (see Section 3.3.2.6).
The CSEL bit in the OPTION register selects an on-chip oscillator clock for programming and
erasing the EEPROM while operating at frequencies below 1MHz.
In special modes there is one extra row of EEPROM, which is used for factory testing. Endurance
and data retention specifications do not apply to these cells.
The erased state of each EEPROM byte is $FF.
3.4.2.1
Note:
bit 0
3
4
5
6
7
8
9
State
on reset
Address
bit 7
bit 6
bit 5
bit 4
bit 3
$003B
ODD
EVEN
0
BYTE
ROW ERASE EELAT EEPGM 0000 0000
11
Writes to EEPROM addresses are inhibited while EEPGM is one. A write to a different
EEPROM location is prevented while a program or erase operation is in progress.
12
EEPROM programming (PPROG)
bit 1
2
10
PPROG — EEPROM programming control register
bit 2
1
ODD — Program odd rows in half of EEPROM (Test)
13
EVEN — Program even rows in half of EEPROM (Test)
If both ODD and EVEN are set to one then all odd and even rows in half of the EEPROM will be
programmed with the same data, within one programming cycle.
Bit 5 — Not implemented; always reads zero.
14
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TPG
MC68HC11PH8
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MOTOROLA
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BYTE — EEPROM byte erase mode
2
3
1 (set)
0 (clear) –
Erase only one byte of EEPROM.
Row or bulk erase mode used.
This bit may be read or written at any time.
ROW — EEPROM row/bulk erase mode (only valid when BYTE = 0)
1 (set)
4
5
–
–
0 (clear) –
Erase only one 16 byte row of EEPROM.
Erase all 768 bytes of EEPROM.
This byte can be read or written at any time.
Table 3-8 Erase mode selection
6
Byte
0
0
1
1
7
8
10
11
12
14
15
–
0 (clear) –
Erase mode.
Normal read or program mode.
This byte can be read or written at any time.
EELAT — EEPROM latch control
1 (set)
–
0 (clear) –
EEPROM address and data bus set up for programming or erasing.
EEPROM address and data bus set up for normal reads.
When the EELAT bit is cleared, the EEPROM can be read as if it were a ROM. The block protect
register has no effect during reads. This bit can be read and written at any time.
EEPGM — EEPROM program command
1 (set)
13
Action
Bulk erase (all 768 bytes)
Row erase (16 bytes)
Byte erase
Byte erase
ERASE — Erase/normal control for EEPROM
1 (set)
9
Row
0
1
0
1
–
Program or erase voltage switched on to EEPROM array.
0 (clear) –
Program or erase voltage switched off to EEPROM array.
This bit can be read at any time but can only be written if EELAT = 1.
Note:
If EELAT = 0 (normal operation) then EEPGM = 0 (programming voltage disconnected).
➡
TPG
MOTOROLA
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OPERATING MODES AND ON-CHIP MEMORY
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During EEPROM programming, the ROW and BYTE bits of PPROG are not used. If the frequency
of the E clock is 1MHz or less, set the CSEL bit in the OPTION register. Remember that the
EEPROM must be erased by a separate erase operation before programming. The following
example of how to program an EEPROM byte assumes that the appropriate bits in BPROT have
been cleared.
PROG
LDAB
STAB
STAA
LDAB
STAB
JSR
CLR
3.4.2.2
#$02
$003B
$0D00
#$03
$003B
DLY10
$003B
EELAT=1
Set EELAT bit
Store data to EEPROM address
EELAT=EEPGM=1
Turn on programming voltage
Delay tEEPROG
Turn off high voltage and set to READ mode
1
2
3
4
5
EEPROM bulk erase
To erase the EEPROM, ensure that the proper bits of the BPROT register are cleared, then
complete the following steps using the PPROG register:
6
1) Write to PPROG with the ERASE, EELAT and appropriate BYTE and ROW
bits set.
7
2) Write to the appropriate EEPROM address with any data. Row erase only
requires a write to any location in the row. Bulk erase is accomplished by
writing to any location in the array.
8
3) Write to PPROG with ERASE, EELAT, EEPGM and the appropriate BYTE
and ROW bits set.
9
4) Delay for time tEEPROG (See Section A.5.6).
5) Clear the EEPGM bit in PPROG to turn off the high voltage.
10
6) Clear the PPROG register to reconfigure the EEPROM address and data
buses for normal operation.
The following is an example of how to bulk erase the 768-byte EEPROM. The CONFIG register is
not affected in this example.
BULKE
LDAB
STAB
STAA
LDAB
STAB
JSR
CLR
#$06
$003B
$0D00
#$07
$003B
DLY10
$003B
EELAT=ERASE=1
Set EELAT bit
Store data to any EEPROM address
EELAT=ERASE=EEPGM=1
Turn on programming voltage
Delay tEEPROG
Turn off high voltage and set to READ mode
11
12
13
14
➡ 15
TPG
MC68HC11PH8
OPERATING MODES AND ON-CHIP MEMORY
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3.4.2.3
2
3
4
6
7
8
PH8.DS03/Modes+mem
EEPROM row erase
The following example shows how to perform a fast erase of 16 bytes of EEPROM:
ROWE
5
—this line does not form part of the document—
LDAB
STAB
STAB
LDAB
STAB
JSR
CLR
3.4.2.4
#$0E
$003B
0,X
#$0F
$003B
DLY10
$003B
ROW=ERASE=EELAT=1
Set to ROW erase mode
Write any data to any address in ROW
ROW=ERASE=EELAT=EEPGM=1
Turn on high voltage
Delay tEEPROG
Turn off high voltage and set to READ mode
EEPROM byte erase
The following is an example of how to erase a single byte of EEPROM:
BYTEE
LDAB
STAB
STAB
LDAB
STAB
JSR
CLR
#$16
$003B
0,X
#$17
$003B
DLY10
$003B
BYTE=ERASE=EELAT=1
Set to BYTE erase mode
Write any data to address to be erased
BYTE=ERASE=EELAT=EEPGM=1
Turn on high voltage
Delay tEEPROG
Turn off high voltage and set to READ mode
9
10
11
12
13
14
15
➡
TPG
MOTOROLA
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OPERATING MODES AND ON-CHIP MEMORY
MC68HC11PH8
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1
CONFIG register programming
Because the CONFIG register is implemented with EEPROM cells, use EEPROM procedures to
erase and program this register. The procedure for programming is the same as for programming
a byte in the EEPROM array, except that the CONFIG register address is used. CONFIG can be
programmed or erased (including byte erase) while the MCU is operating in any mode, provided
that PTCON in BPROT is clear. To change the value in the CONFIG register, complete the
following procedure. Do not initiate a reset until the procedure is complete.
2
3
4
1) Erase the CONFIG register.
2) Program the new value to the CONFIG address.
3) Initiate reset.
5
CONFIG — System configuration register
Address
ConÞguration control (CONFIG)
bit 7
bit 6
bit 5
bit 4
bit 3
bit 2
bit 1
bit 0
State
on reset
6
$003F ROMAD FREEZ CLK4X PAREN NOSEC NOCOP ROMON EEON xxxx xxxx
7
For a description of the bits contained in the CONFIG register refer to Section 3.3.2.1.
CONFIG is made up of EEPROM cells and static working latches. The operation of the MCU is
controlled directly by these latches and not the EEPROM byte. When programming the CONFIG
register, the EEPROM byte is accessed. When the CONFIG register is read, the static latches are
accessed.
8
These bits can be read at any time. The value read is the one latched into the register from the
EEPROM cells during the last reset sequence. A new value programmed into this register is not
readable until after a subsequent reset sequence.
9
On the MC68HC711PH8, and on the MC68HC11PH8 if selected by a mask option, the ROMON
bit can be written at any time if MDA = 1 (expanded mode or special test mode). It cannot be
written in bootstrap mode, and is forced to a logic one in single chip mode.
10
Other bits in CONFIG can be written at any time if SMOD = 1 (bootstrap or special test mode). If
SMOD = 0 (single chip or expanded mode), these bits can only be written using the EEPROM
programming sequence, and none of the bits is readable or active until latched via the next reset.
11
FREEZ is only active in expanded user mode.
12
13
14
➡ 15
TPG
MC68HC11PH8
OPERATING MODES AND ON-CHIP MEMORY
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RAM and EEPROM security
The optional security feature protects the contents of EEPROM and RAM from unauthorized
access. Data, codes, keys, a program, or a key portion of a program, can be protected against
access. To accomplish this, the protection mechanism prevents operation of the device in special
test mode. Only resident programs have unlimited access to the internal EEPROM and RAM and
can read, write, or transfer the contents of these memories. To maintain RAM and EEPROM
security, the following conditions should be satisfied:
4
–
5
The internal ROM must be enabled and mapped at $4000–$FFFF, by setting
the ROMON and ROMAD bits in the CONFIG register. This means that
program execution starts after reset under control of the internal ROM (See
Section 3.3.2.1).
–
6
Access to external addresses should be restricted to data read or write.
Program execution should not point from the internal resources to the
external memory map.
–
The FREEZ bit in the CONFIG register may be set to prevent internal
address visibility on the ports (See Section 3.3.2.1).
7
Alternatively, EEPROM-only security is possible:
–
In expanded mode, program execution is possible in external resources, but
the EEPROM read or write access is restricted by internal hardware;
instructions must be executed from internal ROM/EPROM in the range
$4000 to $43FF (with ROMAD set) or in the range $0000 to $03FF (with
ROMAD clear). Avoid using indexed addressing in this ROM/EPROM range,
and clear temporary copies of EEPROM data before returning to the main
program.
–
As above, the FREEZ bit in the CONFIG register may be set to prevent
internal address visibility on the ports (See Section 3.3.2.1).
8
9
10
Note:
11
A mask option on the MC68HC11PH8 determines whether or not the security feature
is available (it is always available on the MC68HC711PH8). If the feature is available,
then the secure mode can be invoked by programming the NOSEC bit to zero.
Otherwise, the NOSEC bit is permanently set to one, disabling security.
12
13
14
15
➡
TPG
MOTOROLA
3-30
OPERATING MODES AND ON-CHIP MEMORY
MC68HC11PH8
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If the security feature is present and enabled and bootstrap mode is selected, then the following
sequence is performed by the bootstrap program:
1) Output $FF on the SCI.
1
2
2) Turn block protect off. Clear BPROT register.
3
3) If EEPROM is enabled, erase it all.
4) Verify that the EEPROM is erased; if not, begin sequence again.
5) Write $FF to every RAM byte.
4
6) Erase the CONFIG register.
If all the above operations are successful, the bootloading process continues as if the device has
not been secured.
CONFIG — System configuration register
Address
ConÞguration control (CONFIG)
bit 7
bit 6
bit 5
bit 4
bit 3
bit 2
bit 1
bit 0
State
on reset
6
$003F ROMAD FREEZ CLK4X PAREN NOSEC NOCOP ROMON EEON xxxx xxxx
7
For a description of the other bits contained in the CONFIG register refer to Section 3.3.2.1.
NOSEC — EEPROM security disabled
1 (set)
5
–
Disable security.
0 (clear) –
Enable security.
8
With security enabled, selection of special test mode is prevented; single chip and user expanded
modes may be accessed. If the MODA and MODB pins are configured for special test mode, the
part will start in bootstrap mode.
9
10
11
12
13
14
➡ 15
TPG
MC68HC11PH8
OPERATING MODES AND ON-CHIP MEMORY
MOTOROLA
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3
4
5
6
7
THIS PAGE INTENTIONALLY LEFT BLANK
8
9
10
11
12
13
14
15
➡
TPG
MOTOROLA
3-32
OPERATING MODES AND ON-CHIP MEMORY
MC68HC11PH8
76
4
PARALLEL INPUT/OUTPUT
4
The MC68HC11PH8 has up to 54 input/output lines and 8 input-only lines, depending on the
operating mode. To enhance the I/O functions, the data bus of this microcontroller is
non-multiplexed. The following table is a summary of the configuration and features of each port.
Table 4-1 Port configuration
Port
A
B
C
D
E
F
G
H
Note:
Input
pins
Ñ
Ñ
Ñ
Ñ
8
Ñ
Ñ
Ñ
Output
pins
Ñ
Ñ
Ñ
Ñ
Ñ
Ñ
Ñ
Ñ
Bidirectional
pins
8
8
8
6
Ñ
8
8
8
Alternate functions
Timer
High order address and LCD segment drivers
Data bus
SPI1 and SCI1
A/D converter
Low order address
R/W on PG7, LCDBP on PG6, SPI2 and SCI2 (with MI bus)
PWM and modulus timer clock inputs, keyboard interrupt
Do not confuse pin function with the electrical state of that pin at reset. All
general-purpose I/O pins that are configured as inputs at reset are in a high-impedance
state and the contents of the port data registers are undefined; in port descriptions, a
‘u’ indicates this condition. The pin function is mode dependent.
TPG
MC68HC11PH8
PARALLEL INPUT/OUTPUT
MOTOROLA
4-1
77
4.1
Port A
Port A is an 8-bit bidirectional port, with both data and data direction registers. In addition to their
I/O capability, port A pins are shared with timer functions, as shown in the following table.
Pin
PA0
PA1
PA2
PA3
PA4
PA5
PA6
PA7
4
Alternate function
IC3
IC2
IC1
OC5 and/or OC1, or IC4
OC4 and/or OC1
OC3 and/or OC1
OC2 and/or OC1
PAI and/or OC1






 See Section 8 for
 more information.






On reset the pins are configured as general purpose high-impedance inputs.
4.1.1
PORTA — Port A data register
Port A data (PORTA)
Address
bit 7
bit 6
bit 5
bit 4
bit 3
bit 2
bit 1
bit 0
State
on reset
$0000
PA7
PA6
PA5
PA4
PA3
PA2
PA1
PA0
undeÞned
This is a read/write register and is not affected by reset. The bits may be read and written at any
time, but, when a pin is allocated to its alternate function, a write to the corresponding register bit
has no effect on the pin state.
4.1.2
DDRA — Data direction register for port A
Data direction A (DDRA)
State
on reset
Address
bit 7
bit 6
bit 5
bit 4
bit 3
bit 2
bit 1
bit 0
$0001
DDA7
DDA6
DDA5
DDA4
DDA3
DDA2
DDA1
DDA0 0000 0000
DDA[7:0] — Data direction for port A
1 (set)
–
0 (clear) –
The corresponding pin is configured as an output.
The corresponding pin is configured as an input.
TPG
MOTOROLA
4-2
PARALLEL INPUT/OUTPUT
MC68HC11PH8
78
4.2
Port B
Port B is an 8-bit bidirectional port, with both data and data direction registers. In addition to their
I/O capability, port B pins are used as the non-multiplexed high order address pins, as shown in
the following table.
Alternate
function
A8
A9
A10
A11
A12/LCD4
A13/LCD5
A14/ LCD6
A15/LCD7
Pin
PB0
PB1
PB2
PB3
PB4
PB5
PB6
PB7














4
In expanded or test
mode, the pins
become the high
order address lines
and port B is not
included in the
memory map.
The state of the pins on reset is mode dependent. In single chip or bootstrap mode, port B pins
are high-impedance inputs with selectable internal pull-up resistors (see Section 4.9). In
expanded or test mode, port B pins are high order address outputs and PORTB/DDRB are not in
the memory map. Alternatively, four LCD segment drivers can be enabled, in all modes, on
PB4–PB7 (See Section 2.12).
4.2.1
PORTB — Port B data register
Port B data (PORTB)
Address
bit 7
bit 6
bit 5
bit 4
bit 3
bit 2
bit 1
bit 0
State
on reset
$0004
PB7
PB6
PB5
PB4
PB3
PB2
PB1
PB0
undeÞned
bit 0
State
on reset
The bits may be read and written at any time and are not affected by reset.
4.2.2
DDRB — Data direction register for port B
Data direction B (DDRB)
Address
bit 7
bit 6
bit 5
bit 4
bit 3
bit 2
bit 1
$0002
DDB7
DDB6
DDB5
DDB4
DDB3
DDB2
DDB1
DDB0 0000 0000
DDB[7:0] — Data direction for port B
1 (set)
–
0 (clear) –
The corresponding pin is configured as an output.
The corresponding pin is configured as an input.
TPG
MC68HC11PH8
PARALLEL INPUT/OUTPUT
MOTOROLA
4-3
79
4.3
Port C
Port C is an 8-bit bidirectional port, with both data and data direction registers. In addition to their I/O
capability, port C pins are used as the non-multiplexed data bus pins, as shown in the following table.
Pin
PC0
PC1
PC2
PC3
PC4
PC5
PC6
PC7
4
Alternate
function
D0
D1
D2
D3
D4
D5
D6
D7














In expanded or test
mode, the pins
become the data
bus and port C is
not included in the
memory map.
The state of the pins on reset is mode dependent. In single chip or bootstrap mode, port C pins
are high-impedance inputs. In expanded or test modes, port C pins are the data bus I/O and
PORTC/DDRC are not in the memory map.
4.3.1
PORTC — Port C data register
Port C data (PORTC)
Address
bit 7
bit 6
bit 5
bit 4
bit 3
bit 2
bit 1
bit 0
State
on reset
$0006
PC7
PC6
PC5
PC4
PC3
PC2
PC1
PC0
undeÞned
bit 1
bit 0
State
on reset
The bits may be read and written at any time and are not affected by reset.
4.3.2
DDRC — Data direction register for port C
Address
Data direction C (DDRC)
$0007
bit 7
bit 6
bit 5
bit 4
bit 3
bit 2
DDC7 DDC6 DDC5 DDC4 DDC3 DDC2 DDC1 DDC0 0000 0000
DDC[7:0] — Data direction for port C
1 (set)
–
0 (clear) –
The corresponding pin is configured as an output.
The corresponding pin is configured as an input.
TPG
MOTOROLA
4-4
PARALLEL INPUT/OUTPUT
MC68HC11PH8
80
4.4
Port D
Port D is a 6-bit bidirectional port, with both data and data direction registers. In addition to their I/O
capability, port D pins are shared with SCI1 and SPI1 functions, as shown in the following table.
PD0
PD1
Alternate
function
RXD1
TXD1


See Section 5 for
more information.
PD2
PD3
PD4
PD5
MISO1
MOSI1
SCK1
SS1





See Section 7 for
more information.
Pin
4
On reset the pins are configured as general purpose high-impedance inputs.
4.4.1
PORTD — Port D data register
Port D data (PORTD)
Address
bit 7
bit 6
bit 5
bit 4
bit 3
bit 2
bit 1
bit 0
State
on reset
$0008
0
0
PD5
PD4
PD3
PD2
PD1
PD0
undeÞned
This is a read/write register and is not affected by reset. The bits may be read and written at any
time, but, when a pin is allocated to its alternate function, a write to the corresponding register bit
has no effect on the pin state.
4.4.2
DDRD — Data direction register for port D
Data direction D (DDRD)
Address
bit 7
bit 6
$0009
0
0
bit 5
bit 4
bit 3
bit 2
bit 1
bit 0
State
on reset
DDD5 DDD4 DDD3 DDD2 DDD1 DDD0 0000 0000
Bits [7:6] — Reserved; always read zero
DDD[5:0] — Data direction for port D
1 (set)
–
0 (clear) –
The corresponding pin is configured as an output.
The corresponding pin is configured as an input.
TPG
MC68HC11PH8
PARALLEL INPUT/OUTPUT
MOTOROLA
4-5
81
4.5
Port E
Port E is an 8-bit input-only port. In addition to their input capability, port E pins are shared with
A/D functions, as shown in the following table.
Alternate
function
AD0
AD1
AD2
AD3
AD4
AD5
AD6
AD7
Pin
PE0
PE1
PE2
PE3
PE4
PE5
PE6
PE7
4






 See Section 9 for
 more information.






On reset the pins are configured as general purpose high-impedance inputs.
4.5.1
PORTE — Port E data register
Port E data (PORTE)
Address
bit 7
bit 6
bit 5
bit 4
bit 3
bit 2
bit 1
bit 0
State
on reset
$000A
PE7
PE6
PE5
PE4
PE3
PE2
PE1
PE0
undeÞned
This is a read-only register and is not affected by reset. The bits may be read at any time.
Note:
As port E shares pins with the A/D converter, a read of this register may affect any
conversion currently in progress, if it coincides with the sample portion of the
conversion cycle. Hence, normally port E should not be read during the sample portion
of any conversion.
TPG
MOTOROLA
4-6
PARALLEL INPUT/OUTPUT
MC68HC11PH8
82
4.6
Port F
Port F is an 8-bit bidirectional port, with both data and data direction registers. In addition to their
I/O capability, port F pins are used as the non-multiplexed low order address pins, as shown in the
following table.
Pin
PF0
PF1
PF2
PF3
PF4
PF5
PF6
PF7
Alternate
function
A0
A1
A2
A3
A4
A5
A6
A7














4
In expanded or test
mode, the pins
become the low
order address and
port F is not
included in the
memory map.
The state of the pins on reset is mode dependent. In single chip or bootstrap mode, port F pins
are high-impedance inputs with selectable internal pull-up resistors (see Section 4.9). In
expanded or test modes, port F pins are low order address outputs and PORTF/DDRF are not in
the memory map.
4.6.1
PORTF — Port F data register
Port F data (PORTF)
Address
bit 7
bit 6
bit 5
bit 4
bit 3
bit 2
bit 1
bit 0
State
on reset
$0005
PF7
PF6
PF5
PF4
PF3
PF2
PF1
PF0
undeÞned
State
on reset
The bits may be read and written at any time and are not affected by reset.
4.6.2
DDRF — Data direction register for port F
Data direction F (DDRF)
Address
bit 7
bit 6
bit 5
bit 4
bit 3
bit 2
bit 1
bit 0
$0003
DDF7
DDF6
DDF5
DDF4
DDF3
DDF2
DDF1
DDF0 0000 0000
DDF[7:0] — Data direction for port F
1 (set)
–
0 (clear) –
The corresponding pin is configured as an output.
The corresponding pin is configured as an input.
TPG
MC68HC11PH8
PARALLEL INPUT/OUTPUT
MOTOROLA
4-7
83
4.7
Port G
Port G is an 8-bit bidirectional port, with both data and data direction registers. In addition to their
I/O capability, port G pins are shared with R/W, LCD, SCI2 (with MI-bus) and SPI2 functions, as
shown in the following table.
Alternate
function
RXD2
TXD2
MISO2
MOSI2
SCK2
SS2
LCDBP
R/W
Pin
4
PG0
PG1
PG2
PG3
PG4
PG5
PG6
PG7


See Section 5 for
more information.





See Section 7 for
more information.


See Section 2 for
more information.
Pins PG[6:0] are high-impedance inputs with software selectable pull-up resistors, as is PG7 in
single chip and bootstrap modes (see Section 4.9). In expanded or test modes, PG7 is the R/W
output.
4.7.1
PORTG — Port G data register
Port G data (PORTG)
Address
bit 7
bit 6
bit 5
bit 4
bit 3
bit 2
bit 1
bit 0
State
on reset
$007E
PG7
PG6
PG5
PG4
PG3
PG2
PG1
PG0
undeÞned
This is a read/write register and is not affected by reset. The bits may be read and written at any
time, but, when a pin is allocated to its alternate function, a write to the corresponding register bit
has no effect on the pin state.
4.7.2
DDRG — Data direction register for port G
Address
Data direction G (DDRG)
$007F
bit 7
bit 6
bit 5
bit 4
bit 3
bit 2
bit 1
bit 0
State
on reset
DDG7 DDG6 DDG5 DDG4 DDG3 DDG2 DDG1 DDG0 0000 0000
DDG[7:0] — Data direction for port G
1 (set)
–
0 (clear) –
The corresponding pin is configured as an output.
The corresponding pin is configured as an input.
TPG
MOTOROLA
4-8
PARALLEL INPUT/OUTPUT
MC68HC11PH8
84
4.8
Port H
Port H is an 8-bit bidirectional port, with both data and data direction registers. In addition to their
I/O capability, port H pins are shared with modulus timer and PWM functions, as shown in the
following table. Each port H pin configured as an input can be used as a keyboard interrupt, if
enabled (See Section 4.8.3).
Pin
PH0
PH1
PH2
PH3
PH4
PH5
PH6
PH7
Alternate
function
PW1
PW2
PW3
PW4
Ñ
Ñ
Modulus timer C clock input
Modulus timer B clock input
4














See Section 8 for
more information.
On reset the pins are configured as general purpose high-impedance inputs with selectable
internal pull-ups (see Section 4.9).
4.8.1
PORTH — Port H data register
Port H data (PORTH)
Address
bit 7
bit 6
bit 5
bit 4
bit 3
bit 2
bit 1
bit 0
State
on reset
$007C
PH7
PH6
PH5
PH4
PH3
PH2
PH1
PH0
undeÞned
This is a read/write register and is not affected by reset. The bits may be read and written at any
time, but when one of the pins PH[3:0] is allocated to its alternate function of PWM channel, a write
to the corresponding register bit has no affect on the pin state.
4.8.2
DDRH — Data direction register for port H
Address
Data direction H (DDRH)
$007D
bit 7
bit 6
bit 5
bit 4
bit 3
bit 2
bit 1
bit 0
State
on reset
DDH7 DDH6 DDH5 DDH4 DDH3 DDH2 DDH1 DDH0 0000 0000
DDH[7:0] — Data direction for port H
1 (set)
–
0 (clear) –
The corresponding pin is configured as an output.
The corresponding pin is configured as an input.
TPG
MC68HC11PH8
PARALLEL INPUT/OUTPUT
MOTOROLA
4-9
85
4.8.3
Wired-OR interrupt
4.8.3.1
WOIEH — WOI enable (WOIEH)
Wired-OR interrupt enable (WOIEH)
4
Address
bit 7
bit 6
bit 5
bit 4
bit 3
bit 2
bit 1
bit 0
State
on reset
$007B
IEH7
IEH6
IEH5
IEH4
IEH3
IEH2
IEH1
IEH0
0000 0000
IEHx — Port H pin x wired-OR interrupt enable
1 (set)
–
PHx wired-OR interrupt enabled.
0 (clear) –
PHx wired-OR interrupt disabled.
With the wired-OR interrupt function enabled, any port H pin configured as an input may be used
as a keyboard interrupt. A high to low transition on an enabled pin (with all other enabled pins high)
will result in an interrupt. The wired-OR interrupt flag (bit 4 of the port pull-up assignment register)
indicates that an interrupt has occurred (see Section 4.9.1). A wired-OR interrupt can wake the
MCU from STOP or WAIT mode.
TPG
MOTOROLA
4-10
PARALLEL INPUT/OUTPUT
MC68HC11PH8
86
4.9
Internal pull-up resistors
Four of the ports (B, F, G and H) have internal, software selectable pull-up resistors under control
of the port pull-up assignment register (PPAR).
4.9.1
PPAR — Port pull-up assignment register
Port pull-up assignment (PPAR)
Address
bit 7
bit 6
bit 5
$002C
0
0
0
bit 4
bit 3
bit 2
bit 1
bit 0
State
on reset
4
HWOIF HPPUE GPPUE FPPUE BPPUE 0000 1111
Bits [7:5] — Not implemented; always read zero.
HWOIF — Port H wired-OR interrupt flag
1 (set)
–
0 (clear) –
Port H keyboard interrupt request.
No port H keyboard interrupt request.
This bit is cleared by a write to the PPAR register with HWOIF set. When this function is used,
care must be taken when changing pull-up enable bits to prevent accidental clearing of this flag.
xPPUE — Port x pin pull-up enable
These bits control the on-chip pull-up devices connected to all the pins on I/O ports B, F, G and H.
They are collectively enabled or disabled via the PAREN bit in the CONFIG register (see Section
4.10.2).
1 (set)
–
Port x pin on-chip pull-up devices enabled.
0 (clear) –
Port x pin on-chip pull-up devices disabled.
Note:
FPPUE and BPPUE have no effect in expanded mode since ports F and B are
dedicated address bus or LCD outputs.
Note:
When the SCI2 receiver is enabled, the associated pull-up on port G is disabled.
4.10
System configuration
One bit in each of the following registers is directly concerned with the configuration of the I/O
ports. For full details on the other bits in the registers, refer to the appropriate section.
TPG
MC68HC11PH8
PARALLEL INPUT/OUTPUT
MOTOROLA
4-11
87
4.10.1
OPT2 — System configuration options register 2
Address
System conÞg. options 2 (OPT2)
$0038
bit 7
bit 6
bit 5
bit 4
bit 3
LIRDV CWOM STRCH IRVNE LSBF
bit 2
bit 1
bit 0
SPR2 EXT4X DISE
State
on reset
x00x 0000
LIRDV — LIR driven (refer to Section 3)
4
1 (set)
–
0 (clear) –
Enable LIR push-pull drive.
LIR not driven on MODA/LIR pin.
CWOM — Port C wired-OR mode
1 (set)
–
0 (clear) –
Port C outputs are open-drain.
Port C operates normally.
STRCH — Stretch external accesses (refer to Section 3)
1 (set)
–
0 (clear) –
Off-chip accesses are extended by one E clock cycle.
Normal operation.
IRVNE — Internal read visibility/not E (refer to Section 3)
1 (set)
–
0 (clear) –
Data from internal reads is driven out of the external data bus.
No visibility of internal reads on external bus.
In single chip mode this bit determines whether the E clock drives out from the chip.
1 (set)
–
0 (clear) –
E pin is driven low.
E clock is driven out from the chip.
LSBF — LSB first enable (refer to Section 7)
1 (set)
–
SPI1 data is transferred LSB first.
0 (clear) –
SPI1 data is transferred MSB first.
SPR2 — SPI1 clock rate select (refer to Section 7)
EXT4X — 4XLCK or EXTAL clock output select (refer to Section 3
1 (set)
–
EXTALi clock output on the 4XOUT pin.
0 (clear) –
4XCLK clock output on the 4XOUT pin.
TPG
MOTOROLA
4-12
PARALLEL INPUT/OUTPUT
MC68HC11PH8
88
DISE— E clock output disable (refer to Section 3)
1 (set)
–
0 (clear) –
4.10.2
No E clock output.
E clock is output normally.
CONFIG — System configuration register
Address
ConÞguration control (CONFIG)
bit 7
bit 6
bit 5
bit 4
bit 3
bit 2
bit 1
bit 0
State
on reset
4
$003F ROMAD FREEZ CLK4X PAREN NOSEC NOCOP ROMON EEON xxxx xxxx
ROMAD — ROM/EPROM mapping control (refer to Section 3)
1 (set)
–
0 (clear) –
ROM/EPROM addressed from $4000 to $FFFF.
ROM/EPROM addressed from $0000 to $BFFF (expanded mode
only).
FREEZ — Expanded user mode address bus freeze (refer to Section 3)
1 (set)
–
0 (clear) –
The external bus is only active when externally mapped resources
are accessed (expanded mode only).
Normal operation.
CLK4X — 4X clock enable (refer to Section 3)
1 (set)
–
0 (clear) –
4XCLK or EXTALi driven out on the 4XOUT pin.
4XOUT pin disabled.
PAREN — Pull-up assignment register enable
1 (set)
–
0 (clear) –
Pull-ups can be enabled using PPAR register.
All pull-ups disabled.
NOSEC — EEPROM security disabled (refer to Section 3)
1 (set)
–
Disable security.
0 (clear) –
Enable security.
NOCOP — COP system disable (refer to Section 10)
1 (set)
–
0 (clear) –
COP system disabled.
COP system enabled (forces reset on timeout).
TPG
MC68HC11PH8
PARALLEL INPUT/OUTPUT
MOTOROLA
4-13
89
ROMON — ROM/EPROM enable (refer to Section 3)
1 (set)
–
0 (clear) –
ROM/EPROM present in the memory map.
ROM/EPROM disabled from the memory map.
EEON — EEPROM enable (refer to Section 3)
1 (set)
4
–
0 (clear) –
EEPROM is present in the memory map.
EEPROM is disabled from the memory map.
TPG
MOTOROLA
4-14
PARALLEL INPUT/OUTPUT
MC68HC11PH8
90
5
SERIAL COMMUNICATIONS INTERFACE†
The serial communications interface (SCI) is a universal asynchronous receiver transmitter
(UART). It has a non-return to zero (NRZ) format (one start, eight or nine data, and one stop bit)
that is compatible with standard RS-232 systems.
5
The SCI shares I/O with two of port D’s pins:
Pin
PD0
PD1
Alternate
function
RXD1
TXD1
The SCI transmit and receive functions are enabled by TE and RE respectively, in SCCR2.
The SCI features enabled on this MCU include: 13-bit modulus prescaler, idle line detect,
receiver-active flag, transmitter and receiver hardware parity. A block diagram of the enhanced
baud rate generator is shown in Figure 5-1. See Table 5-1 for example baud rate control values.
ST4XCK
Internal
phase 2 clock
13-bit counter
÷ 16
Reset
13-bit compare
EQ
÷2
Sync
SCBDH/L: SCI baud control
Transmitter
baud rate
clock
Receiver
baud rate
clock
Figure 5-1 SCI baud rate generator circuit diagram
†
The MC68HC11PH8 contains two serial communications interfaces, both having similar
operation. For ease of reference, a full description of SCI1 (PD0/RXD1, PD1/TXD1) is given
first, followed by a summary of SCI2 (Section 5.8), detailing its differences.
TPG
MC68HC11PH8
SERIAL COMMUNICATIONS INTERFACE
MOTOROLA
5-1
91
5.1
Data format
The serial data format requires the following conditions:
5
–
An idle-line condition before transmission or reception of a message.
–
A start bit, logic zero, transmitted or received, that indicates the start of each
character.
–
Data that is transmitted and received least significant bit (LSB) first.
–
A stop bit, logic one, used to indicate the end of a frame. (A frame consists
of a start bit, a character of eight or nine data bits, and a stop bit.)
–
A break (defined as the transmission or reception of a logic zero for some
multiple number of frames).
Selection of the word length is controlled by the M bit of SCCR1.
5.2
Transmit operation
The SCI transmitter includes a parallel data register (SCDRH/SCDRL) and a serial shift register.
The contents of the shift register can only be written through the parallel data register. This double
buffered operation allows a character to be shifted out serially while another character is waiting
in the parallel data register to be transferred into the shift register. The output of the shift register
is applied to TXD as long as transmission is in progress or the transmit enable (TE) bit of serial
communication control register 2 (SCCR2) is set. The block diagram, Figure 5-2, shows the
transmit serial shift register and the buffer logic at the top of the figure.
5.3
Receive operation
During receive operations, the transmit sequence is reversed. The serial shift register receives
data and transfers it to the parallel receive data registers (SCDRH/SCDRL) as a complete word.
This double buffered operation allows a character to be shifted in serially while another character
is still in the serial data registers. An advanced data recovery scheme distinguishes valid data from
noise in the serial data stream. The data input is selectively sampled to detect receive data, and
majority sampling logic determines the value and integrity of each bit.
TPG
MOTOROLA
5-2
SERIAL COMMUNICATIONS INTERFACE
MC68HC11PH8
92
T8 SCDRH/SCDRL (transmit buffer)
LOOPS
10/11-bit TX shift register
WOMS
TXD1
0 L
M
WAKE
ST4XCK
clock
LOOPS
ILT
M
PE
PE
PT
PT
Transmitter
control
TE
SBK
TIE
PE
TE
PT
RE
RE
RWU
Receiver
RWU
SBK
SCBDL
SCCR2
WAKE
ILIE
5
Rate generator
Flag control
TCIE
RIE
WOMS
SCBDH
SCCR1
H 8 7
control
M
LOOPS
WOMS
ILT
10/11-bit RX shift register
8 7
0
STOP
RAF
PF
SCSR2
FE
NF
OR
IDLE
TC
SCSR1
RDRF
RXD1
START
SCDRH/SCDRL (receive buffer)
R8
TDRE
Data
recovery
OR
RIE
&
IDLE
ILIE
&
RDRF
RIE
&
SCI interrupt request
+
TC
TCIE
TDRE
TIE
&
Note:
= always reads as zero
&
Internal data bus
Figure 5-2 SCI1 block diagram
TPG
MC68HC11PH8
SERIAL COMMUNICATIONS INTERFACE
MOTOROLA
5-3
93
5.4
Wake-up feature
The wake-up feature reduces SCI service overhead in multiple receiver systems. Software for
each receiver evaluates the first character or frame of each message. All receivers are placed in
wake-up mode by writing a one to the RWU bit in the SCCR2 register. When RWU is set, the
receiver-related status flags (RDRF, IDLE, OR, NF, FE, and PF) are inhibited (cannot be set).
Although RWU can be cleared by a software write to SCCR2, to do so would be unusual. Normally
RWU is set by software and is cleared automatically with hardware. Whenever a new message
begins, logic alerts the dormant receivers to wake up and evaluate the initial character of the new
message.
5
Two methods of wake-up are available: idle-line wake-up and address mark wake-up. During
idle-line wake-up, a dormant receiver activates as soon as the RXD line becomes idle. In the
address mark wake-up, logic one in the most significant bit (MSB) of a character activates all
sleeping receivers. To use either receiver wake-up method, establish a software addressing
scheme to allow the transmitting devices to direct messages to individual receivers or to groups
of receivers. This addressing scheme can take any form as long as all transmitting and receiving
devices are programmed to understand the same scheme.
5.4.1
Idle-line wake-up
Clearing the WAKE bit in SCCR1 register enables idle-line wake-up mode. In idle-line wake-up
mode, all receivers are active (RWU bit in SCCR2 = 0) when each message begins. The first
frames of each message are addressing frames. Each receiver in the system evaluates the
addressing frames of a message to determine if the message is intended for that receiver. When
a receiver finds that the message is not intended for it, it sets the RWU bit. Once set, the RWU
control bit disables all but the necessary receivers for the remainder of the message, thus reducing
software overhead for the remainder of that message. As soon as an idle line is detected by
receiver logic, hardware automatically clears the RWU bit so that the first frames of the next
message can be evaluated by all receivers in the system. This type of receiver wake-up requires
a minimum of one idle frame time between messages, and no idle time between frames within a
message.
5.4.2
Address-mark wake-up
Setting the WAKE bit in SCCR1 register enables address-mark wake-up mode. The address-mark
wake-up method uses the MSB of each frame to differentiate between address information
(MSB = 1) and actual message data (MSB = 0). All frames consist of seven information bits (eight
bits if M bit in SCCR1 = 1) and an MSB which, when set to one, indicates an address frame. The
first frames of each message are addressing frames. Receiver logic evaluates these marked
frames to determine the receivers for which that message is intended. When a receiver finds that
the message is not intended for it, it sets the RWU bit. Once set, the RWU control bit disables all
but the necessary receivers for the remainder of the message, thus reducing software overhead
TPG
MOTOROLA
5-4
SERIAL COMMUNICATIONS INTERFACE
MC68HC11PH8
94
for the remainder of that message. When the next message begins, its first frame will have the
MSB set which will automatically clear the RWU bit and indicate that this is an addressing frame.
This frame is always the first frame received after wake-up because the RWU bit is cleared before
the stop bit for the first frame is received. This method of wake-up allows messages to include idle
times, however, there is a loss in efficiency due to the extra bit time required for the address bit in
each frame.
5.5
SCI error detection
Four error conditions can occur during SCI operation. These error conditions are: serial data
register overrun, received bit noise, framing, and parity error. Four bits (OR, NF, FE, and PF) in
serial communications status register 1 (SCSR1) indicate if one of these error conditions exists.
5
The overrun error (OR) bit is set when the next byte is ready to be transferred from the receive
shift register to the serial data registers (SCDRH/SCDRL) and the registers are already full (RDRF
bit is set). When an overrun error occurs, the data that caused the overrun is lost and the data that
was already in serial data registers is not disturbed. The OR is cleared when the SCSR is read
(with OR set), followed by a read of the SCI data registers.
The noise flag (NF) bit is set if there is noise on any of the received bits, including the start and
stop bits. The NF bit is not set until the RDRF flag is set. The NF bit is cleared when the SCSR is
read (with FE equal to one) followed by a read of the SCI data registers.
When no stop bit is detected in the received data character, the framing error (FE) bit is set. FE is
set at the same time as the RDRF. If the byte received causes both framing and overrun errors,
the processor only recognizes the overrun error. The framing error flag inhibits further transfer of
data into the SCI data registers until it is cleared. The FE bit is cleared when the SCSR is read
(with FE equal to one) followed by a read of the SCI data registers.
The parity error flag (PF) is set if received data has incorrect parity. The flag is cleared by a read
of SCSR1 with PE set, followed by a read of SCDR.
5.6
SCI registers
There are eight addressable registers in the SCI. SCBDH, SCBDL, SCCR1, and SCCR2 are
control registers. The contents of these registers control functions and indicate conditions within
the SCI. The status registers SCSR1 and SCSR2 contain bits that indicate certain conditions
within the SCI. SCDRH and SCDRL are SCI data registers. These double buffered registers are
used for the transmission and reception of data, and are used to form the 9-bit data word for the
SCI. If the SCI is being used with 7 or 8-bit data, only SCDRL needs to be accessed. Note that if
9-bit data format is used, the upper register should be written first to ensure that it is transferred
to the transmitter shift register with the lower register.
TPG
MC68HC11PH8
SERIAL COMMUNICATIONS INTERFACE
MOTOROLA
5-5
95
5.6.1
SCBDH, SCBDL — SCI baud rate control registers
Address
bit 7
bit 6
bit 5
bit 4
bit 3
bit 2
bit 1
bit 0
State
on reset
SCI1 baud rate high (SCBDH)
$0070
BTST
BSPL
BRST SBR12 SBR11 SBR10 SBR9
SBR8 0000 0000
SCI1 baud rate low (SCBDL)
$0071
SBR7
SBR6
SBR5
SBR0 0000 0100
SBR4
SBR3
SBR2
SBR1
The contents of this register determine the baud rate of the SCI.
BTST — Baud register test (Test mode only)
BSPL — Baud rate counter split (Test mode only)
5
BRST — Baud rate reset (Test mode only)
SBR[12:0] — SCI baud rate selects
Use the following formula to calculate SCI baud rate. Refer to the table of baud rate control values
for example rates:
ST 4 XCK
SCI baud rate = ----------------------------16 × ( 2 BR )
where the baud rate control value (BR) is the contents of SCBDH/L (BR = 1, 2, 3,... 8191).
For example, to obtain a baud rate of 1200 with a ST4XCK frequency of 12MHz, the baud register
(SCBDH/L) should contain $0138 (see Table 5-1).
The clock rate generator is disabled if BR = 0, or if neither the receiver nor transmitter is enabled
(both RE and TE in SCCR2 are cleared).
Writes to the baud rate registers will only be successful if the last (or only) byte written is SCBDL.
The use of an STD instruction is recommended as it guarantees that the bytes are written in the
correct order.
Note:
ST4XCK may be the output of the PLL circuit or it may be the EXTAL input of the MCU
(see Section 2.5, Figure 8-1 and Figure 8-2).
TPG
MOTOROLA
5-6
SERIAL COMMUNICATIONS INTERFACE
MC68HC11PH8
96
Table 5-1 Example SCI baud rate control values
Target
baud
rate
110
150
300
600
1200
2400
4800
9600
19200
38400
5.6.2
ST4XCK frequency
8 MHz
12 MHz
16 MHz
Dec value Hex value Dec value Hex value Dec value Hex value
2272
$08E0
3409
$0D51
4545
$11C1
1666
$0682
2500
$09C4
3333
$0D05
833
$0341
1250
$04E2
1666
$0682
416
$01A0
625
$0271
833
$0341
208
$00D0
312
$0138
416
$01A0
104
$0068
156
$009C
208
$00D0
52
$0034
78
$004E
104
$0068
26
$001A
39
$0027
52
$0034
13
$000D
20
$0014
26
$001A
13
$000D
5
SCCR1 — SCI control register 1
Address
SCI1 control 1 (SCCR1)
bit 7
bit 6
$0072 LOOPS WOMS
bit 5
bit 4
bit 3
bit 2
bit 1
bit 0
State
on reset
0
M
WAKE
ILT
PE
PT
0000 0000
The SCCR1 register provides the control bits that determine word length and select the method
used for the wake-up feature.
LOOPS — SCI loop mode enable
1 (set)
–
0 (clear) –
SCI transmit and receive are disconnected from TXD and RXD pins,
and transmitter output is fed back into the receiver input.
SCI transmit and receive operate normally.
Both the transmitter and receiver must be enabled to use the LOOP mode. When the LOOP mode
is enabled, the TXD pin is driven high (idle line state) if the transmitter is enabled.
WOMS — Wired-OR mode for SCI pins (PD1, PD0)
1 (set)
–
0 (clear) –
TXD and RXD are open drains if operating as outputs.
TXD and RXD operate normally.
Bit 5 — Not implemented; always reads zero
TPG
MC68HC11PH8
SERIAL COMMUNICATIONS INTERFACE
MOTOROLA
5-7
97
M — Mode (select character format)
1 (set)
–
Start bit, 9 data bits, 1 stop bit.
0 (clear) –
Start bit, 8 data bits, 1 stop bit.
WAKE — Wake-up by address mark/idle
1 (set)
–
0 (clear) –
Wake-up by address mark (most significant data bit set).
Wake-up by IDLE line recognition.
ILT — Idle line type
5
1 (set)
–
0 (clear) –
Long (SCI counts ones only after stop bit).
Short (SCI counts consecutive ones after start bit).
This bit determines which of two types of idle line detection method is used by the SCI receiver.
In short mode the stop bit and any bits that were ones before the stop bit will be considered as
part of that string of ones, possibly resulting in erroneous or premature detection of an idle line
condition. In long mode the SCI system does not begin counting ones until a stop bit is received.
PE — Parity enable
1 (set)
–
Parity enabled.
0 (clear) –
Parity disabled.
PT — Parity type
1 (set)
–
0 (clear) –
Parity odd (an odd number of ones causes parity bit to be zero, an
even number of ones causes parity bit to be one).
Parity even (an even number of ones causes parity bit to be zero, an
odd number of ones causes parity bit to be one).
TPG
MOTOROLA
5-8
SERIAL COMMUNICATIONS INTERFACE
MC68HC11PH8
98
5.6.3
SCCR2 — SCI control register 2
SCI1 control 2 (SCCR2)
Address
bit 7
bit 6
bit 5
bit 4
bit 3
bit 2
bit 1
bit 0
State
on reset
$0073
TIE
TCIE
RIE
ILIE
TE
RE
RWU
SBK
0000 0000
The SCCR2 register provides the control bits that enable or disable individual SCI functions.
TIE — Transmit interrupt enable
1 (set)
–
0 (clear) –
SCI interrupt requested when TDRE status flag is set.
TDRE interrupts disabled.
5
TCIE — Transmit complete interrupt enable
1 (set)
–
0 (clear) –
SCI interrupt requested when TC status flag is set.
TC interrupts disabled.
RIE — Receiver interrupt enable
1 (set)
–
0 (clear) –
SCI interrupt requested when RDRF flag or the OR status flag is set.
RDRF and OR interrupts disabled.
ILIE — Idle line interrupt enable
1 (set)
–
0 (clear) –
SCI interrupt requested when IDLE status flag is set.
IDLE interrupts disabled.
TE — Transmitter enable
1 (set)
–
Transmitter enabled.
0 (clear) –
Transmitter disabled.
RE — Receiver enable
1 (set)
–
Receiver enabled.
0 (clear) –
Receiver disabled.
RWU — Receiver wake-up control
1 (set)
–
0 (clear) –
Wake-up enabled and receiver interrupts inhibited.
Normal SCI receiver.
SBK — Send break
1 (set)
–
0 (clear) –
Break codes generated as long as SBK is set.
Break generator off.
TPG
MC68HC11PH8
SERIAL COMMUNICATIONS INTERFACE
MOTOROLA
5-9
99
5.6.4
SCSR1 — SCI status register 1
SCI1 status 1 (SCSR1)
Address
bit 7
bit 6
bit 5
bit 4
bit 3
bit 2
bit 1
bit 0
State
on reset
$0074
TDRE
TC
RDRF
IDLE
OR
NF
FE
PF
1100 0000
The bits in SCSR1 indicate certain conditions in the SCI hardware and are automatically cleared
by special acknowledge sequences.
TDRE — Transmit data register empty flag
5
1 (set)
–
0 (clear) –
SCDR empty.
SCDR busy.
This flag is set when SCDR is empty. Clear the TDRE flag by reading SCSR1 with TDRE set and
then writing to SCDR.
TC — Transmit complete flag
1 (set)
–
0 (clear) –
Transmitter idle.
Transmitter busy.
This flag is set when the transmitter is idle (no data, preamble, or break transmission in progress).
Clear the TC flag by reading SCSR1 with TC set and then writing to SCDR.
RDRF — Receive data register full flag
1 (set)
–
0 (clear) –
SCDR full.
SCDR empty.
Once cleared, IDLE is not set again until the RXD line has been active and becomes idle again.
RDRF is set if a received character is ready to be read from SCDR. Clear the RDRF flag by
reading SCSR1 with RDRF set and then reading SCDR.
IDLE — Idle line detected flag
1 (set)
–
0 (clear) –
RXD line is idle.
RXD line is active.
This flag is set if the RXD line is idle. Once cleared, IDLE is not set again until the RXD line has
been active and becomes idle again. The IDLE flag is inhibited when RWU = 1. Clear IDLE by
reading SCSR1 with IDLE set and then reading SCDR.
TPG
MOTOROLA
5-10
SERIAL COMMUNICATIONS INTERFACE
MC68HC11PH8
100
OR — Overrun error flag
1 (set)
–
0 (clear) –
Overrun detected.
No overrun.
OR is set if a new character is received before a previously received character is read from SCDR.
Clear the OR flag by reading SCSR1 with OR set and then reading SCDR.
NF — Noise error flag
1 (set)
–
0 (clear) –
Noise detected.
Unanimous decision.
NF is set if the majority sample logic detects anything other than a unanimous decision. Clear NF
by reading SCSR1 with NF set and then reading SCDR.
5
FE — Framing error
1 (set)
–
0 (clear) –
Zero detected.
Stop bit detected.
FE is set when a zero is detected where a stop bit was expected. Clear the FE flag by reading
SCSR1 with FE set and then reading SCDR.
PF — Parity error flag
1 (set)
–
0 (clear) –
Incorrect parity detected.
Parity correct.
PF is set if received data has incorrect parity. Clear PF by reading SCSR1 with PE set and then
reading SCDR.
TPG
MC68HC11PH8
SERIAL COMMUNICATIONS INTERFACE
MOTOROLA
5-11
101
5.6.5
SCSR2 — SCI status register 2
SCI1 status 2 (SCSR2)
Address
bit 7
bit 6
bit 5
bit 4
bit 3
bit 2
bit 1
bit 0
State
on reset
$0075
0
0
0
0
0
0
0
RAF
0000 0000
In the SCSR2 only bit 0 is used, to indicate receiver active. The other seven bits always read zero.
Bits [7:1] — Not implemented; always read zero
RAF — Receiver active flag (read only)
1 (set)
5
–
0 (clear) –
5.6.6
A character is being received.
A character is not being received.
SCDRH, SCDRL — SCI data high/low registers
Address
bit 7
bit 6
bit 5
bit 4
bit 3
bit 2
bit 1
bit 0
State
on reset
SCI1 data high (SCDRH)
$0076
R8
T8
0
0
0
0
0
0
undeÞned
SCI1 data low (SCDRL)
$0077
R7T7
R6T6
R5T5
R4T4
R3T3
R2T2
R1T1
R0T0
undeÞned
SCDRH/SCDRL is a parallel register that performs two functions. It is the receive data register
when it is read, and the transmit data register when it is written. Reads access the receive data
buffer and writes access the transmit data buffer. Data received or transmitted is double buffered.
If the SCI is being used with 7 or 8-bit data, only SCDRL needs to be accessed. Note that if 9-bit
data format is used, the upper register should be written first to ensure that it is transferred to the
transmitter shift register with the lower register.
R8 — Receiver bit 8
Ninth serial data bit received when SCI is configured for a nine data bit operation
T8 — Transmitter bit 8
Ninth serial data bit transmitted when SCI is configured for a nine data bit operation
Bits [5:0] — Not implemented; always read zero
R/T[7:0] — Receiver/transmitter data bits [7:0]
SCI data is double buffered in both directions.
TPG
MOTOROLA
5-12
SERIAL COMMUNICATIONS INTERFACE
MC68HC11PH8
102
5.7
Status flags and interrupts
The SCI transmitter has two status flags. These status flags can be read by software (polled) to
tell when certain conditions exist. Alternatively, a local interrupt enable bit can be set to enable
each of these status conditions to generate interrupt requests. Status flags are automatically set
by hardware logic conditions, but must be cleared by software. This provides an interlock
mechanism that enables logic to know when software has noticed the status indication. The
software clearing sequence for these flags is automatic — functions that are normally performed
in response to the status flags also satisfy the conditions of the clearing sequence.
TDRE and TC flags are normally set when the transmitter is first enabled (TE set to one). The
TDRE flag indicates there is room in the transmit queue to store another data character in the
transmit data register. The TIE bit is the local interrupt mask for TDRE. When TIE is zero, TDRE
must be polled. When TIE and TDRE are one, an interrupt is requested.
5
The TC flag indicates the transmitter has completed the queue. The TCIE bit is the local interrupt
mask for TC. When TCIE is zero, TC must be polled; when TCIE is one and TC is one, an interrupt
is requested.
Writing a zero to TE requests that the transmitter stop when it can. The transmitter completes any
transmission in progress before shutting down. Only an MCU reset can cause the transmitter to
stop and shut down immediately. If TE is cleared when the transmitter is already idle, the pin
reverts to its general purpose I/O function (synchronized to the bit-rate clock). If anything is being
transmitted when TE is cleared, that character is completed before the pin reverts to general
purpose I/O, but any other characters waiting in the transmit queue are lost. The TC and TDRE
flags are set at the completion of this last character, even though TE has been disabled.
5.7.1
Receiver flags
The SCI receiver has seven status flags, three of which can generate interrupt requests. The
status flags are set by the SCI logic in response to specific conditions in the receiver. These flags
can be read (polled) at any time by software. Refer to Figure 5-3, which shows SCI interrupt
arbitration.
When an overrun takes place, the new character is lost, and the character that was in its way in
the parallel receive data register (RDR) is undisturbed. RDRF is set when a character has been
received and transferred into the parallel RDR. The OR flag is set instead of RDRF if overrun
occurs. A new character is ready to be transferred into the RDR before a previous character is read
from the RDR.
The NF, FE and PF flags provide additional information about the character in the RDR, but do not
generate interrupt requests.
The receiver active flag (RAF) indicates that the receiver is busy.
The last receiver status flag and interrupt source come from the IDLE flag. The RXD line is idle if it has
constantly been at logic one for a full character time. The IDLE flag is set only after the RXD line has
been busy and becomes idle. This prevents repeated interrupts for the time RXD remains idle.
TPG
MC68HC11PH8
SERIAL COMMUNICATIONS INTERFACE
MOTOROLA
5-13
103
Note:
Begin
RDRF = 1?
The bit names shown are for SCI1. The diagram
applies equally to SCI2, when the appropriate bit
names are substituted.
Yes
No
OR = 1?
Yes
No
5
TDRE = 1?
Yes
No
TIE = 1?
Yes
TCIE = 1?
RE = 1?
Yes
No
Yes
No
No
IDLE = 1?
Yes
No
No
TC = 1?
RIE = 1?
TE = 1?
Yes
No
Yes
No
Yes
ILIE = 1?
No
Yes
RE = 1?
Yes
No
No valid SCI
interrupt request
Valid SCI
interrupt request
Figure 5-3 Interrupt source resolution within SCI
TPG
MOTOROLA
5-14
SERIAL COMMUNICATIONS INTERFACE
MC68HC11PH8
104
5.8
SCI2
In addition to the subsystem described in the above paragraphs (SCI1), the MC68HC11PH8 has
another, similar, SCI module (SCI2). This system is identical to SCI1, with the following
exceptions:
–
SCI2 shares I/O with two port G pins:
Alternate
function
RXD2
TXD2
Pin
PG0
PG1
5.8.1
5
–
The SCI2 transmit and receive functions are enabled by TE2 and RE2
respectively, in S2CR2.
–
SCI1 functions and data are handled by a register block at $0070–$0077.
The corresponding registers for SCI2 are at addresses $0050–$0057, as
described in the following sections.
–
The SCI2 baud rate register is at address $0050/51.
–
In addition to the SCI functions,SCI2 is also used for MI BUS, controlled by
bit 5 of S2CR1. Refer to Section 6 for full details of MI BUS operation.
S2BDH, S2BDL — SCI2 baud rate control registers
Address
bit 7
bit 6
bit 5
bit 4
bit 3
bit 2
bit 1
bit 0
State
on reset
SCI2/MI baud high (S2BDH)
$0050
B2TST B2SPL B2RST S2B12 S2B11 S2B10 S2B9
S2B8 0000 0000
SCI2/MI baud low (S2BDL)
$0051
S2B7
S2B0 0000 0100
S2B6
S2B5
S2B4
S2B3
S2B2
S2B1
The contents of this register determine the baud rate for SCI2. For details of the bits and the
corresponding baud rates, see Section 5.6.1. This register also controls the MI BUS clock rate
(see Section 6).
TPG
MC68HC11PH8
SERIAL COMMUNICATIONS INTERFACE
MOTOROLA
5-15
105
5.8.2
S2CR1 — SCI2 control register 1
Address
SCI2/MI control 1 (S2CR1)
bit 7
bit 6
bit 5
bit 4
$0052 LOPS2 WOMS2 MIE2
M2
bit 2
bit 1
bit 0
State
on reset
WAKE2 ILT2
PE2
PT2
0000 0000
bit 3
The S2CR1 register provides the control bits that determine word length and select the method
used for the wake-up feature. Bit 5 has an MI BUS control function detailed below (for details of
the other bits see Section 5.6.2).
WOMS2 — Wired-OR mode for SCI pins (PG1, PG0)
5
1 (set)
–
0 (clear) –
TXD2 and RXD2 are open drains if operating as inputs.
TXD2 and RXD2 operate normally.
MIE2 — Motorola interface bus enable 2
1 (set)
–
0 (clear) –
MI BUS is enabled for this subsystem.
The SCI functions normally.
When MIE2 is set, the SCI2 registers, bits and pins assume the functionality required for MI BUS.
5.8.3
S2CR2 — SCI2 control register 2
SCI2/MI control 2 (S2CR2)
Address
bit 7
bit 6
bit 5
bit 4
bit 3
bit 2
$0053
TIE2
TCIE2
RIE2
ILIE2
TE2
RE2
bit 1
bit 0
State
on reset
RWU2 SBK2 0000 0000
The S2CR2 register provides the control bits that enable or disable individual SCI functions. For
details of the bits, see Section 5.6.3.
5.8.4
S2SR1 — SCI2 status register 1
Address
SCI2/MI status 1 (S2SR1)
bit 7
$0054 TDRE2
bit 6
TC2
bit 5
bit 4
RDRF2 IDLE2
bit 3
bit 2
bit 1
bit 0
State
on reset
OR2
NF2
FE2
PF2
1100 0000
The bits in S2SR1 indicate certain conditions in the SCI hardware and are automatically cleared
by special acknowledge sequences. For details of the bits, see Section 5.6.4.
TPG
MOTOROLA
5-16
SERIAL COMMUNICATIONS INTERFACE
MC68HC11PH8
106
5.8.5
S2SR2 — SCI2 status register 2
SCI2/MI status 2 (S2SR2)
Address
bit 7
bit 6
bit 5
bit 4
bit 3
bit 2
bit 1
$0055
0
0
0
0
0
0
0
bit 0
State
on reset
RAF2 0000 0000
In the S2SR2 only bit 0 is used, to indicate receiver active (see Section 5.6.5 for details). The other
seven bits always read zero.
5.8.6
S2DRH, S2DRL — SCI2 data high/low registers
Address
bit 7
bit 6
bit 5
bit 4
bit 3
bit 2
bit 1
bit 0
State
on reset
SCI2/MI data high (S2DRH)
$0056
R8B
T8B
0
0
0
0
0
0
undeÞned
SCI2/MI data low (S2DRL)
$0057
5
R7T7B R6T6B R5T5B R4T4B R3T3B R2T2B R1T1B R0T0B undeÞned
S2DRH/S2DRL is a parallel register that performs two functions. It is the receive data register
when it is read, and the transmit data register when it is written. Reads access the receive data
buffer and writes access the transmit data buffer. Data received or transmitted is double buffered.
See Section 5.6.6 for more details.
TPG
MC68HC11PH8
SERIAL COMMUNICATIONS INTERFACE
MOTOROLA
5-17
107
5
THIS PAGE INTENTIONALLY LEFT BLANK
TPG
MOTOROLA
5-18
SERIAL COMMUNICATIONS INTERFACE
MC68HC11PH8
108
6
MOTOROLA INTERCONNECT BUS (MI BUS)
The Motorola Interconnect Bus (MI BUS) is a serial communications protocol which supports
distributed real-time control efficiently and with a high degree of noise immunity, at a typical bit rate
for the data transfer of 20kHz. The MI BUS is suitable for medium speed networks requiring very
low cost multiplex wiring; only one wire is required to connect to slave devices.†
The MI BUS uses a push-pull sequence to transfer data. The master device, which in this case is
the MC68HC11PH8, sends a push field to the slave devices connected to the bus. The push field
contains data plus an address that is recognized by one of the slaves. The slave addressed returns
data which the master pulls from the MI BUS over the same wire. Specific details of the message
format are covered later in this section. The MCU (master) can take the bus at any time, with a
start bit that violates the rules of Manchester biphase encoding. Up to eight slave devices may be
addressed by the MI BUS. Other features of MI BUS include message validation, error detection,
and default value setting.
6
On the MC68HC11PH8 the MI BUS module shares the same pins on port G as the SCI2 module.
Data is transmitted (or ‘pushed’) via the TXD pin, and received (‘pulled’) via the RXD pin. While
data is being pushed, RXD will be disconnected from the receiver circuitry. The message frame is
handled automatically in hardware. The MCU register interface is similar to that for the SCI.
Pin
PG0
PG1
Alternate
function
RXD2
TXD2
MI BUS functions are enabled by MIE2 in S2CR1
†
Related information on Motorola’s MI BUS is contained in the following Motorola publications:
EB409/D — The MI BUS and Product family for Multiplexing Systems
AN475/D — Single Wire MI BUS Controlling Stepper Motors
BR477/D — Smart Mover – Stepper Motors with Integrated Serial Bus Controller
TPG
MC68HC11PH8
MOTOROLA INTERCONNECT BUS (MI BUS)
MOTOROLA
6-1
109
6.1
Push-pull sequence
Communication between the MCU and the slave device always utilizes the same frame
organization. First, the MCU sends serial data to the selected device. This data field is called the
‘push field’. At the end of the push field, the selected device automatically sends back to the MCU
the data held during the push sequence. The MCU reads the serial data sent by the selected
device. This data is called the ‘pull field’ and contains status information followed by the
end-of-frame information from the selected device.
Time slots
Push (biphase coded)
Push-pull function
TXD pin (true data)
1 0
0 1
MI BUS wire
0 1 2 3 4 5 6 7
Start
Push
Start sync D0 D1 D2 D3 D4 A0
Data
A1
Pull
A2 sync
Address
Push Þeld
(driven by MCU)
NRZ
Data
End of frame
Pull Þeld
(driven by slave)
New frame
Bit Þelds
Stop
S3
S2
S1
6
Pull (NRZ coded)
Message frame
Figure 6-1 MI BUS timing
6.1.1
The push field
The push field consists of a start bit, a push synchronization bit, a push data field and a push
address field. The start consists of three time slots having the dominant logical state ‘0’. The start
marks the beginning of the message frame by violation of the rule of the Manchester code. The
push synchronization bit consists of a biphase coded ‘0’. Biphase coding will be discussed later.
The push data field consists of five bits of biphase coded data. The push address consists of three
bits of biphase coded data. Data and address are written to the lower byte of the SCI data register
(S2DRL). The push data occupies the lower five bits and the push address occupies the upper
three bits of the register.
TPG
MOTOROLA
6-2
MOTOROLA INTERCONNECT BUS (MI BUS)
MC68HC11PH8
110
6.1.2
The pull field
The pull field consists of a pull synchronization bit, a pull data field and an end of frame. The pull
synchronization bit is a biphase coded ‘1’ and is initiated by the MCU during the time slot after the
last address bit of the push field. The pull data field consists of an NRZ coded transmission, each
bit taking one time slot. Once shifted in, the pull data is stored in the lower byte of the SCI data
register (S2DRL). The end-of-frame field is a square wave signal having a typical frequency of
20kHz ± 1% tolerance (i.e. the bit rate of the push field) when the data sent to the selected device
is valid.
6.2
Biphase coding
Manchester biphase L coding is used for the push field bits. Each bit requires two time slots to
encode the logic value of the bit. This encoding allows the detection of a single error at the time
slot level. Bits are encoded as follows:
1 (set)
–
In the first time slot, the logic level is set to zero, followed by a logic
level one in the second time slot;
0 (clear) –
In the first time slot, the logic level is set to one, followed by a logic
level zero in the second time slot.
Ô0Õ
6
Ô1Õ
Biphase coded signal
0
1
2
3
4
5
a
6
7
0
1
b
2
3
4
5
a
6
7
t
b
Biphase detection
aÕ
a
bÕ
b
aÕ
a
bÕ
b
Noise detection
Figure 6-2 Biphase coding and error detection
TPG
MC68HC11PH8
MOTOROLA INTERCONNECT BUS (MI BUS)
MOTOROLA
6-3
111
6.3
Message validation
The communication between the MCU and the selected device is valid when the MCU reads a pull
data field having correct codes (excluding the codes ‘111’ and ‘000’) followed by a square wave
signal, having a frequency of 20kHz, contained in the end-of-frame information.
An MI BUS error is detected when the pull field contains the code ‘111’ followed by the
end-of-frame permanently tied to logical state ‘1’. This means that the communication between the
MCU and the selected device was not accomplished.
6.3.1
Controller detected errors
There are three different MI BUS error types which are detected by the selected slave device and
are not mutually exclusive. The MCU cannot determine which error occurred.
6
–
Noise error Slave devices take two samples in each time slot of the biphase
encoded push field. An error occurs when the two samples for each time slot
are not the same logical level.
–
Biphase error Slave devices receiving the push field detect the biphase
code. An error occurs when the two time slots of the biphase code do not
yield a logical exclusive-OR function.
–
Field error A field error is detected when the fixed-form of the push field is
violated.
6.3.2
MCU detected errors
There is a fourth error that can be detected by the MCU. This error causes the noise flag (NF) to
be asserted in the S2SR1 register during the push field sequence.
–
Bit error A bit error can be detected by the MCU during the push field. The
MI BUS serial system monitors the bus via on-chip hardware at the RXD pin
at the same time as sending data. A bit error is detected at that bit time when
the value monitored is different from the bit value sent.
TPG
MOTOROLA
6-4
MOTOROLA INTERCONNECT BUS (MI BUS)
MC68HC11PH8
112
T8
LOPS2
10/11-bit TX shift register
WOMS2
H 8 7
MIE2
M2
TXD2
0 L
WAKE2
ST4XCK
clock
ILT2
PE2
MIE2
PT2
PT2
Transmitter
control
TE2
SBK2
TIE2
Rate generator
Flag control
TCIE2
ILIE2
TE2
MIE2
RE2
Receiver
RWU2
6
S2BDL
S2CR2
RIE2
RE2
WOMS
S2BDH
S2CR1
Transmit buffer
control
SBK2
WOMS
10/11-bit RX shift register
8 7
STOP
Receive buffer
RAF2
S2SR2
NF2
OR2
TC2
S2SR1
RDRF2
RXD2
START
R8
TDRE2
Data
recovery
0
IDLE2
ILIE2
&
RDRF2
RIE2
&
SCI interrupt request
+
TC2
TCIE2
TDRE2
TIE2
&
Note:
&
= always reads as zero
= not used in MI BUS mode
Internal data bus
Figure 6-3 MI BUS block diagram
TPG
MC68HC11PH8
MOTOROLA INTERCONNECT BUS (MI BUS)
MOTOROLA
6-5
113
6.4
Interfacing to MI BUS
Physically the MI BUS consists of only a single wire. In the example shown in Figure 6-4, only a
single transistor and a few passive components are required to connect up the MC68HC11PH8
for full MI BUS operation.
VDD
+12V
4.7kΩ
1.2kΩ
18V
MI BUS
VDD
T1
TX
3.9kΩ
6
VDD
10kΩ
MCU
22kΩ
10kΩ
RX
VSS
Figure 6-4 A typical interface between the MC68HC11PH8 and the MI BUS
The transistor serves both to drive the MI BUS during the push field and to protect the MCU TX
pin from voltage transients generated in the wiring. Without the transistor, EMI could damage the
TX pin. Similarly, the input pin (RX) is protected from EMI by clamping it to the MCU supply rails
with two diodes. When a load dump occurs, the zener diode (18V) is switched on and hence turns
the transistor on; this generates the logic ‘0’ state on the MI BUS. After eight time slots (200ms)
of continuous ‘0’ state, all devices on the MI BUS will have their outputs disabled.
The MI BUS line can take two states, recessive or dominant. The recessive state (‘1’) is
represented by 5V, through a pull-up resistor of 10kΩ. The dominant state (‘0’) is represented by
a maximum 0.3V (VCESAT of the transistor, T1).
The bus load depends on the number of devices on the bus. Each device has a pull-up resistor of
10kΩ. An external termination resistor is used to stabilize the load resistance of the bus at 600Ω.
TPG
MOTOROLA
6-6
MOTOROLA INTERCONNECT BUS (MI BUS)
MC68HC11PH8
114
6.5
MI BUS clock rate
The MI BUS clock rate is set via the SCI baud registers. To use the MI BUS, the ST4XCK clock
frequency that drives the SCI clock generator must be selected to match the minimum resolution
of the MI BUS logic. This is expressed by the following formula:
ST4XCK = 16 • 2n • (2 • Push_field_bit_rate) = 16 • 2n • 40kHz = n • 1280kHz
where ‘n’ is an integer and 20kHz is the minimum Push field bit rate for the MI BUS. Values for
ST4XCK could be 1280kHz, 2560kHz, …, n • 1280kHz. The value ‘n’ is the modulus for the
MI BUS baud register (see Section 6.6.2). ST4XCK may be the output of the PLL circuit or it may
be the EXTAL input of the MCU. Refer to Section 2.5.
6.6
SCI2/MI BUS registers
MI BUS operation is controlled by the same group of registers as is used for the SCI. However the
functions of some of the bits are modified when in MI BUS mode. A description of the registers,
as applicable to the MI BUS function, is given here.
Note:
6
In MI BUS mode, bits that have no meaning are reserved by Motorola, and are not
described.
TPG
MC68HC11PH8
MOTOROLA INTERCONNECT BUS (MI BUS)
MOTOROLA
6-7
115
6.6.1
INIT2 — EEPROM mapping and MI BUS delay register
EEPROM mapping (INIT2)
Address
bit 7
bit 6
bit 5
bit 4
bit 3
bit 2
$0037
EE3
EE2
EE1
EE0
STRX
0
bit 1
bit 0
State
on reset
M2DL1 M2DL0 0000 0000
This register sets the MI BUS delay time. INIT2 may be read at any time but bits 7–4 may be
written only once after reset in normal modes (bits 3, 1 and 0 may be written at any time).
EE[3:0] — EEPROM map position (Refer to Section 3.3.2.3.)
EEPROM is located at $xD00–$xFFF, where x is the hexadecimal digit represented by EE[3:0].
STRX — Stretch extended (Refer to Section 3.3.2.3)
6
1 (set)
–
0 (clear) –
All external accesses are extended by one E clock cycle.
Only external access from $0000 to $1FFF (ROMAD set) or from
$C000 to $DFFF (ROMAD clear) are extended by one E clock cycle.
Bit 2 — Not implemented, always read zero.
M2DL1:M2DL0 — MI BUS delay select
These bits are used to set up the delay for the start of the NRZ receive for MI BUS operation as
shown (for a 20kHz bit rate) in the following table.
M2DL1
0
0
1
1
M2DL0
0
1
0
1
Delay factor Delay time(1)
1
1.5625µs(2)
2
3.1250µs
3
4.6875µs
4
6.2500µs
(1) 20kHz bit rate requires 25µs (40kHz) time slots.
(2) 25µs ÷ 16
TPG
MOTOROLA
6-8
MOTOROLA INTERCONNECT BUS (MI BUS)
MC68HC11PH8
116
6.6.2
S2BDH, S2BDL — MI BUS clock rate control registers
Address
bit 7
bit 6
bit 5
bit 4
bit 3
bit 2
bit 1
bit 0
State
on reset
SCI2/MI baud high (S2BDH)
$0050
B2TST B2SPL B2RST S2B12 S2B11 S2B10 S2B9
S2B8 0000 0000
SCI2/MI baud low (S2BDL)
$0051
S2B7
S2B0 0000 0100
S2B6
S2B5
S2B4
S2B3
S2B2
S2B1
The contents of this register determine the clock rate for MI BUS.
S2B[12:0] — SCI baud rate/ MI BUS clock rate selects
Use the following formula to calculate MI BUS clock rate. Refer to the table of baud rate control
values (see Table 5-1) for example rates:
ST 4 XCK
MI BUS clock rate = ----------------------------16 × ( 2 BR )
6
where the baud rate control value (BR) is the contents of S2BDH/L (BR = 1, 2, 3,... 8191).
The clock rate generator is disabled if BR = 0, or if neither the receiver nor transmitter is enabled
(both RE and TE in SCCR2 are cleared).
Writes to the baud rate registers will only be successful if the last (or only) byte written is SCBDL.
The use of an STD instruction is recommended as it guarantees that the bytes are written in the
correct order.
Note:
ST4XCK may be the output of the PLL circuit or it may be the EXTAL input of the MCU.
Selection is made by the MCS bit in the PLLCR (see Section 2.5).
6.6.3
S2CR1 — MI BUS control register 1
SCI2/MI control 1 (S2CR1)
Address
bit 7
$0052
Ñ
bit 6
bit 5
WOMS2 MIE2
bit 4
bit 3
bit 2
bit 1
bit 0
State
on reset
Ñ
Ñ
Ñ
Ñ
PT2
0000 0000
WOMS2 — Wired-OR mode for MI BUS pins (PG0, PG1)
1 (set)
–
0 (clear) –
TXD2 and RXD2 are open drains if operating as outputs.
TXD2 and RXD2 operate normally.
MIE2 — Motorola interface bus enable 2
1 (set)
–
0 (clear) –
MI BUS is enabled for this subsystem.
The SCI functions normally.
When MIE2 is set, the SCI2 registers, bits and pins assume the functionality required for MI BUS.
TPG
MC68HC11PH8
MOTOROLA INTERCONNECT BUS (MI BUS)
MOTOROLA
6-9
117
PT2 — MI BUS TX polarity (See Section 5.6.2)
1 (set)
–
0 (clear) –
MI BUS transmit pin will send inverted data.
MI BUS transmit pin functions normally.
This control bit allows for different driver interfaces between the MCU and the MI BUS wire.
6.6.4
S2CR2 — MI BUS control register 2
Address
bit 7
bit 6
bit 5
bit 4
bit 3
bit 2
bit 1
$0053
Ñ
Ñ
RIE2
Ñ
TE2
RE2
Ñ
SCI2/MI control 2 (S2CR2)
bit 0
State
on reset
SBK2 0000 0000
RIE2 — Receiver interrupt enable 2
6
1 (set)
–
0 (clear) –
MI BUS interrupt requested when RDRF2 flag is set.
RDRF2 and OR2 interrupts disabled.
TE2 — Transmitter enable 2
1 (set)
–
0 (clear) –
Transmitter enabled and port pin dedicated to the MI BUS.
Transmitter disabled.
RE2 — Receiver enable 2
1 (set)
–
0 (clear) –
Port pin dedicated to the MI BUS; the receiver is enabled by a pull
sync and is inhibited during a push field.
Receiver disabled.
SBK2 — Send break 2
1 (set)
–
0 (clear) –
MI transmit line is set low for 20 time slots.
No action.
When an MI BUS wire is held low for eight or more time slots an internal circuit on any slave device
connected to the bus may reset or preset the device with default values.
TPG
MOTOROLA
6-10
MOTOROLA INTERCONNECT BUS (MI BUS)
MC68HC11PH8
118
6.6.5
S2SR1 — MI BUS status register 1
SCI2/MI status 1 (S2SR1)
Address
bit 7
bit 6
bit 5
bit 4
bit 3
bit 2
bit 1
bit 0
State
on reset
$0054
Ñ
Ñ
RDRF2
Ñ
OR2
NF2
Ñ
Ñ
1100 0000
The bits in S2SR1 indicate certain conditions in the MI BUS hardware and are automatically
cleared by special acknowledge sequences. The receive related flag bits in S2SR1 (RDRF2, OR2
and NF2) are cleared by a read of this register followed by a read of the transmit/receive data
register. However, only those bits that were set when S2SR1 was read will be cleared by the
subsequent read of the transmit/receive data register.
RDRF2 — Receive data register full flag 2
1 (set)
–
0 (clear) –
Contents of the receiver serial shift register have been transferred to
the receiver data register.
6
Contents of the receiver serial shift register have not been
transferred to the receiver data register.
This bit is set when the contents of the receiver serial shift register have been transferred to the
receiver data register.
The EOF (end-of-frame) during an MI BUS pull-field is a continuous square wave, which will result
in multiple RDRFs. This may be dealt with in any of the following ways:
–
By clearing the RIE2 mask, ignoring unneeded RDRF2s, initiating a push
field, waiting for TDRE2† and then clearing the RDRF2;
–
By clearing the RE2 bit when a pull field is complete, followed by setting the RE2
bit after the TDRE2† flag associated with the next push field is asserted;
–
By disabling the MI BUS.
OR2 — Bit error 2
1 (set)
–
0 (clear) –
A bit error has been detected.
No bit error has been detected.
This bit is set when a push field bit value on the MI BUS does not match the bit value that was
sent. This is known as an MI BUS bit error. OR2 does not generate an interrupt request in MI BUS
mode.
†
Note that TDRE2 and TC2 will both behave in the same way as during normal SCI
transmissions. The MI BUS will still be receiving when the TC2 bit becomes set, hence any
queued transmission will not start until the current pull field has finished.
See also Section 5.6.4.
TPG
MC68HC11PH8
MOTOROLA INTERCONNECT BUS (MI BUS)
MOTOROLA
6-11
119
NF2 — Noise error flag 2
1 (set)
–
0 (clear) –
Noise detected.
No noise detected.
This bit is set when noise is detected on the receive line during an MI BUS pull field.
6.6.6
S2SR2 — MI BUS2 status register 2
SCI/MI 2 status 2 (S2SR2)
Address
bit 7
bit 6
bit 5
bit 4
bit 3
bit 2
bit 1
$0055
0
0
0
0
0
0
0
bit 3
bit 2
bit 1
bit 0
State
on reset
RAF2 0000 0000
RAF2 — Receiver active flag (read only)
6
1 (set)
–
0 (clear) –
6.6.7
A character is being received.
A character is not being received.
S2DRL — MI BUS2 data register
Address
SCI/MI 2 data low (S2DRL)
$0057
bit 7
bit 6
bit 5
bit 4
bit 0
State
on reset
R7T7B R6T6B R5T5B R4T4B R3T3B R2T2B R1T1B R0T0B undeÞned
0
1
0
1
S1
S2
S3
1
Pull Þeld
A2
A1
A0
D4
D3
D2
D1
D0
Push Þeld
This register forms the 8-bit data/address word for the MI push field and contains the 3-bit data
word received as the MI pull field.
R/T[7:0] — Receiver/transmitter data bits [7:0]
READ: Reads access the three bits of pull field data (stored in bits 3–1) of the read-only MI BUS
receive data register. Bits [7:4, 0] are a fixed data pattern when a valid status and end-of-frame is
returned. A valid status is represented by the following data pattern: 0101 xxx1 (bits 7–0), where
‘xxx’ is the status. All ones in the receive data register indicate that an error occurred on the
MI BUS. Bits are received LSB first by the MCU, and the status bits map as shown in the above
table.
WRITE: Writes access the eight bits of the write-only MI BUS transmit data register. MI BUS
devices require a 5-bit data pattern followed by a 3-bit address pattern to be sent during the push
field. The data pattern is mapped to the lowest five bits of the data register and the address to the
highest three bits, as shown in the above table. Thus MI-data[4:0] is written to S2DRL[4:0] and
MI-address[2:0] is written to S2DRL[7:5].
TPG
MOTOROLA
6-12
MOTOROLA INTERCONNECT BUS (MI BUS)
MC68HC11PH8
120
7
SERIAL PERIPHERAL INTERFACE†
The serial peripheral interface (SPI), an independent serial communications subsystem, allows
the MCU to communicate synchronously with peripheral devices, such as transistor-transistor
logic (TTL) shift registers, liquid crystal (LCD) display drivers, analog-to-digital converter
subsystems, and other microprocessors. The SPI is also capable of inter-processor
communication in a multiple master system. The SPI system can be configured as either a master
or a slave device, with data rates as high as one half of the E clock rate when configured as a
master and as fast as the E clock rate when configured as a slave.
The SPI shares I/O with four of port D’s pins and is enabled by SPE in the SPCR:
Pin
PD2
PD3
PD4
PD5
7.1
7
Alternate
function
MISO1
MOSI1
SCK1
SS1
Functional description
The central element in the SPI system is the block containing the shift register and the read data
buffer (see Figure 7-1). The system is single buffered in the transmit direction and double buffered
in the receive direction. This means that new data for transmission cannot be written to the shifter
until the previous transfer is complete; however, received data is transferred into a parallel read
data buffer so the shifter is free to accept a second serial character. As long as the first character
is read out of the read data buffer before the next serial character is ready to be transferred, no
overrun condition occurs. A single MCU register address is used for reading data from the read
data buffer and for writing data to the shifter.
The SPI status block represents the SPI status functions (transfer complete, write collision, and mode
fault) performed by the serial peripheral status register (SPSR). The SPI control block represents those
functions that control the SPI system through the serial peripheral control register (SPCR).
†
The MC68HC11PH8 contains two serial peripheral interfaces having similar operation. For ease
of reference, a full description of SPI1 is given first, followed by a summary of SPI2 (Section 7.6).
TPG
MC68HC11PH8
SERIAL PERIPHERAL INTERFACE
MOTOROLA
7-1
121
7.2
SPI transfer formats
During an SPI transfer, data is simultaneously transmitted and received. A serial clock line
synchronizes shifting and sampling of the information on the two serial data lines. A slave select
line allows individual selection of a slave SPI device; slave devices that are not selected do not
interfere with SPI bus activities. On a master SPI device, the select line can optionally be used to
indicate a multiple master bus contention. Refer to Figure 7-2.
MISO
PD2
S
M
M
MCU
system clock
MOSI
PD3
S
8-bit shift register
Read data buffer
Divider
Shift control logic
Pin
control
logic
÷8 ÷16 ÷32 ÷64 ÷128
Clock
LSBF
SPI clock (master)
Select
S
Clock
logic
SCK
PD4
M
OPT2 Ð Options register 2
MSTR
SPE
MSTR
SPR2
SS
PD5
DWOM
÷4
LSBF
SPE
SPI control
SPSR Ð SPI status register
SPR0
SPR1
CPHA
CPOL
MSTR
DWOM
SPE
SPIE
MODF
WCOL
SPIE
SPIF
7
÷2
SPCR Ð SPI control register
SPDR Ð SPI data register
SPI interrupt
request
Internal bus
Figure 7-1 SPI block diagram
TPG
MOTOROLA
7-2
SERIAL PERIPHERAL INTERFACE
MC68HC11PH8
122
SCK cycle #
(for reference)
1
2
3
4
5
6
7
8
SCK (CPOL=0)
SCK (CPOL=1)
Sample input
Data out (CPHA=0)
MSB
6
5
4
3
2
1
LSB
Sample input
Data out (CPHA=1)
MSB
6
5
4
3
2
1
LSB
SS (to slave)
Note: this Þgure shows the LSBF=0 (default) case. If LSBF=1, data is transferred in the reverse order (LSB Þrst).
Figure 7-2 SPI transfer format
7.2.1
7
Clock phase and polarity controls
Software can select one of four combinations of serial clock phase and polarity using two bits in
the SPI control register (SPCR). The clock polarity is specified by the CPOL control bit, which
selects an active high or active low clock, and has no significant effect on the transfer format. The
clock phase (CPHA) control bit selects one of two different transfer formats. The clock phase and
polarity should be identical for the master SPI device and the communicating slave device. In
some cases, the phase and polarity are changed between transfers to allow a master device to
communicate with peripheral slaves having different requirements.
When CPHA equals zero, the SS line must be deasserted and reasserted between each
successive serial byte. Also, if the slave writes data to the SPI data register (SPDR) while SS is
low, a write collision error results.
When CPHA equals one, the SS line can remain low between successive transfers.
7.3
SPI signals
The following paragraphs contain descriptions of the four SPI signals: master in slave out (MISO),
master out slave in (MOSI), serial clock (SCK), and slave select (SS).
Any SPI output line must have its corresponding data direction bit in DDRD register set. If the DDR
bit is clear, that line is disconnected from the SPI logic and becomes a general-purpose input. All
SPI input lines are forced to act as inputs regardless of the state of the corresponding DDR bits in
DDRD register.
TPG
MC68HC11PH8
SERIAL PERIPHERAL INTERFACE
MOTOROLA
7-3
123
7.3.1
Master in slave out
MISO is one of two unidirectional serial data signals. It is an input to a master device and an output
from a slave device. The MISO line of a slave device is placed in the high-impedance state if the
slave device is not selected.
7.3.2
Master out slave in
The MOSI line is the second of the two unidirectional serial data signals. It is an output from a
master device and an input to a slave device. The master device places data on the MOSI line a
half-cycle before the clock edge that the slave device uses to latch the data.
7.3.3
7
Serial clock
SCK, an input to a slave device, is generated by the master device and synchronizes data
movement in and out of the device through the MOSI and MISO lines. Master and slave devices
are capable of exchanging a byte of information during a sequence of eight clock cycles.
There are four possible timing relationships that can be chosen by using control bits CPOL and
CPHA in the serial peripheral control register (SPCR). Both master and slave devices must operate
with the same timing. The SPI clock rate select bits, SPR[1:0], in the SPCR of the master device,
select the clock rate. In a slave device, SPR[1:0] have no effect on the operation of the SPI.
7.3.4
Slave select
The slave select SS input of a slave device must be externally asserted before a master device
can exchange data with the slave device. SS must be low before data transactions begin and must
stay low for the duration of the transaction.
The SS line of the master must be held high. If it goes low, a mode fault error flag (MODF) is set
in the serial peripheral status register (SPSR). To disable the mode fault circuit, write a one in bit
5 of the port D data direction register. This sets the SS pin to act as a general-purpose output,
rather than a dedicated input to the slave select circuit, thus inhibiting the mode fault flag. The
other three lines are dedicated to the SPI whenever the serial peripheral interface is on.
The state of the master and slave CPHA bits affects the operation of SS. CPHA settings should be
identical for master and slave. When CPHA = 0, the shift clock is the OR of SS with SCK. In this clock
phase mode, SS must go high between successive characters in an SPI message. When CPHA =
1, SS can be left low between successive SPI characters. In cases where there is only one SPI slave
MCU, its SS line can be tied to VSS as long as only CPHA = 1 clock mode is used.
TPG
MOTOROLA
7-4
SERIAL PERIPHERAL INTERFACE
MC68HC11PH8
124
7.4
SPI system errors
Two kinds of system errors can be detected by the SPI system. The first type of error arises in a
multiple-master system when more than one SPI device simultaneously tries to be a master. This
error is called a mode fault. The second type of error, write collision, indicates that an attempt was
made to write data to the SPDR while a transfer was in progress.
When the SPI system is configured as a master and the SS input line goes to active low, a mode
fault error has occurred — usually because two devices have attempted to act as master at the
same time. In the case where more than one device is concurrently configured as a master, there
is a chance of contention between two pin drivers. For push-pull CMOS drivers, this contention
can cause permanent damage. The mode fault detection circuitry attempts to protect the device
by disabling the drivers. The MSTR control bit in the SPCR and all four DDRD control bits
associated with the SPI are cleared and an interrupt is generated (subject to masking by the SPIE
control bit and the I bit in the CCR).
Other precautions may need to be taken to prevent driver damage. If two devices are made
masters at the same time, the mode fault detector does not help protect either one unless one of
them selects the other as slave. The amount of damage possible depends on the length of time
both devices attempt to act as master.
A write collision error occurs if the SPDR is written while a transfer is in progress. Because the
SPDR is not double buffered in the transmit direction, writes to SPDR cause data to be written
directly into the SPI shift register. Because this write corrupts any transfer in progress, a write
collision error is generated. The transfer continues undisturbed, and the write data that caused the
error is not written to the shifter.
7
A write collision is normally a slave error because a slave has no control over when a master
initiates a transfer. A master knows when a transfer is in progress, so there is no reason for a
master to generate a write-collision error, although the SPI logic can detect write collisions in both
master and slave devices.
The SPI configuration determines the characteristics of a transfer in progress. For a master, a
transfer begins when data is written to SPDR and ends when SPIF is set. For a slave with CPHA
equal to zero, a transfer starts when SS goes low and ends when SS returns high. In this case,
SPIF is set at the middle of the eighth SCK cycle when data is transferred from the shifter to the
parallel data register, but the transfer is still in progress until SS goes high. For a slave with CPHA
equal to one, transfer begins when the SCK line goes to its active level, which is the edge at the
beginning of the first SCK cycle. The transfer ends when SPIF is set, for a slave in which CPHA=1.
7.5
SPI registers
The three SPI registers, SPCR, SPSR, and SPDR, provide control, status, and data storage
functions. Refer to the following information for a description of how these registers are organized.
TPG
MC68HC11PH8
SERIAL PERIPHERAL INTERFACE
MOTOROLA
7-5
125
7.5.1
SPCR — SPI control register
SPI control (SPCR)
Address
bit 7
bit 6
$0028
SPIE
SPE
bit 5
bit 4
bit 3
bit 2
bit 1
DWOM MSTR CPOL CPHA SPR1
bit 0
State
on reset
SPR0 0000 01uu
SPIE — Serial peripheral interrupt enable
1 (set)
–
0 (clear) –
A hardware interrupt sequence is requested each time SPIF or
MODF is set.
SPI interrupts are inhibited.
Set the SPIE bit to a one to request a hardware interrupt sequence each time the SPIF or MODF
status flag is set. SPI interrupts are inhibited if this bit is clear or if the I bit in the condition code
register is one.
SPE — Serial peripheral system enable
1 (set)
7
–
0 (clear) –
Port D [5:2] is dedicated to the SPI.
Port D has its default I/O functions and the clock generator is stopped.
When the SPE bit is set, the port D pins 2, 3, 4, and 5 are dedicated to the SPI functions and lose
their general purpose I/O functions. When the SPI system is enabled and expects any of PD[4:2]
to be inputs then those pins will be inputs regardless of the state of the associated DDRD bits. If
any of PD[4:2] are expected to be outputs then those pins will be outputs only if the associated
DDRD bits are set. However, if the SPI is in the master mode, DDD5 determines whether PD5 is
an error detect input (DDD5 = 0) or a general-purpose output (DDD5 = 1).
DWOM — Port D wired-OR mode
1 (set)
–
0 (clear) –
Port D [5:2] buffers configured for open-drain outputs.
Port D [5:2] buffers configured for normal CMOS outputs.
MSTR — Master mode select
1 (set)
–
0 (clear) –
Master mode
Slave mode
CPOL — Clock polarity
1 (set)
–
0 (clear) –
SCK is active low.
SCK is active high.
When the clock polarity bit is cleared and data is not being transferred, the SCK pin of the master
device has a steady state low value. When CPOL is set, SCK idles high. Refer to Figure 7-2 and
Section 7.2.1.
TPG
MOTOROLA
7-6
SERIAL PERIPHERAL INTERFACE
MC68HC11PH8
126
CPHA — Clock phase
The clock phase bit, in conjunction with the CPOL bit, controls the clock-data relationship between
master and slave. The CPHA bit selects one of two different clocking protocols. Refer to Figure
7-2 and Section 7.2.1.
SPR1 and SPR0 — SPI clock rate selects
These two bits select the SPI clock rate, as shown in Table 7-1. Note that SPR2 is located in the
OPT2 register, and that its state on reset is zero.
Table 7-1 SPI clock rates
7.5.2
SPR[2:0]
E clock
divide ratio
000
001
010
011
100
101
110
111
2
4
16
32
8
16
64
128
SPI clock frequency (≡ baud rate) for:
E = 2MHz
E = 3MHz
E = 4MHz
1.0 MHz
1.5 MHz
2.0 MHz
500 kHz
750kHz
1.0 MHz
125 kHz
187.5 kHz
250 kHz
62.5 kHz
93.7 kHz
125 kHz
250 kHz
375 kHz
500 kHz
125 kHz
187.5 kHz
250 kHz
31.3 kHz
46.9 kHz
62.5 kHz
15.6 kHz
23.4 kHz
31.3 kHz
7
SPSR — SPI status register
SPI status (SPSR)
Address
bit 7
bit 6
bit 5
bit 4
bit 3
bit 2
bit 1
bit 0
State
on reset
$0029
SPIF
WCOL
0
MODF
0
0
0
0
0000 0000
SPIF — SPI interrupt complete flag
1 (set)
–
0 (clear) –
Data transfer to external device has been completed.
No valid completion of data transfer.
SPIF is set upon completion of data transfer between the processor and the external device. If
SPIF goes high, and if SPIE is set, a serial peripheral interrupt is generated. To clear the SPIF bit,
read the SPSR with SPIF set, then access the SPDR. Unless SPSR is read (with SPIF set) first,
attempts to write SPDR are inhibited.
TPG
MC68HC11PH8
SERIAL PERIPHERAL INTERFACE
MOTOROLA
7-7
127
WCOL — Write collision
1 (set)
–
0 (clear) –
Write collision.
No write collision.
Clearing the WCOL bit is accomplished by reading the SPSR (with WCOL set) followed by an
access of SPDR. Refer to Section 7.3.4 and Section 7.4.
MODF — Mode fault
1 (set)
–
0 (clear) –
Mode fault.
No mode fault.
To clear the MODF bit, read the SPSR (with MODF set), then write to the SPCR. Refer to Section
7.3.4 and Section 7.4.
Bits [5, 3:0] — Not implemented; always read zero.
7
7.5.3
SPDR — SPI data register
SPI data (SPDR)
Address
bit 7
bit 6
bit 5
bit 4
bit 3
bit 2
bit 1
bit 0
State
on reset
$002A
(bit 7)
(6)
(5)
(4)
(3)
(2)
(1)
(bit 0)
undeÞned
The SPDR is used when transmitting or receiving data on the serial bus. Only a write to this
register initiates transmission or reception of a byte, and this only occurs in the master device. At
the completion of transferring a byte of data, the SPIF status bit is set in both the master and slave
devices.
A read of the SPDR is actually a read of a buffer. To prevent an overrun and the loss of the byte
that caused the overrun, the first SPIF must be cleared by the time a second transfer of data from
the shift register to the read buffer is initiated.
SPI is double buffered in and single buffered out.
TPG
MOTOROLA
7-8
SERIAL PERIPHERAL INTERFACE
MC68HC11PH8
128
7.5.4
OPT2 — System configuration options register 2
Address
System conÞg. options 2 (OPT2)
$0038
bit 7
bit 6
bit 5
bit 4
bit 3
LIRDV CWOM STRCH IRVNE LSBF
bit 2
bit 1
bit 0
SPR2 EXT4X DISE
State
on reset
x00x 0000
LIRDV — LIR driven (refer to Section 3)
1 (set)
–
0 (clear) –
Enable LIR push-pull drive.
LIR not driven on MODA/LIR pin.
CWOM — Port C wired-OR mode (refer to Section 4)
1 (set)
–
0 (clear) –
Port C outputs are open-drain.
Port C operates normally.
STRCH — Stretch external accesses (refer to Section 3)
1 (set)
–
0 (clear) –
Off-chip accesses are extended by one E clock cycle.
7
Normal operation.
IRVNE — Internal read visibility/not E (refer to Section 3)
1 (set)
–
0 (clear) –
Data from internal reads is driven out of the external data bus.
No visibility of internal reads on external bus.
In single chip mode this bit determines whether the E clock drives out from the chip.
1 (set)
–
0 (clear) –
E pin is driven low.
E clock is driven out from the chip.
LSBF — LSB first enable
1 (set)
–
SPI1 data is transferred LSB first.
0 (clear) –
SPI1 data is transferred MSB first.
If this bit is set, data, which is usually transferred MSB first, is transferred LSB first. LSBF does not
affect the position of the MSB and LSB in the data register. Reads and writes of the data register
always have MSB in bit 7.
SPR2 — SPI clock rate select
When set, SPR2 adds a divide-by-4 prescaler to the SPI clock chain. With the two bits in the
SPCR, this bit specifies the SPI clock rate. Refer to Table 7-1.
TPG
MC68HC11PH8
SERIAL PERIPHERAL INTERFACE
MOTOROLA
7-9
129
EXT4X — 4XCLK or EXTAL clock output select (refer to Section 3)
1 (set)
–
EXTALi clock output on the 4XOUT pin.
0 (clear) –
4XCLK clock output on the 4XOUT pin.
DISE — E clock output disable (refer to Section 3)
1 (set)
–
0 (clear) –
7.6
No E clock output.
E clock is output normally.
SPI2
In addition to the subsystem described in the above paragraphs (SPI1), the MC68HC11PH8 has
another SPI module (SPI2). This system is identical to SPI1, with the following exceptions:
–
SPI2 shares I/O with four port G pins:
7
Pin
PG2
PG3
PG4
PG5
–
Alternate
function
MISO2
MOSI2
SCK2
SS2
SPI1 functions and data are handled by a register block at $0028–$002A
along with the system configuration options register 2 at address $0038. The
corresponding registers for SPI2 are at addresses $004C–$004E along with
the SPI2 control options register at address $004F. The SPI2 registers are
described in the following sections.
TPG
MOTOROLA
7-10
SERIAL PERIPHERAL INTERFACE
MC68HC11PH8
130
7.6.1
SP2CR — SPI2 control register
Address
SPI2 control (SP2CR)
$004C
bit 7
bit 6
bit 5
bit 4
bit 3
bit 2
bit 1
bit 0
State
on reset
SP2IE SP2E GWOM MSTR2 CPOL2 CPHA2 SP2R1 SP2R0 0000 01uu
For details of the functions of bits 2,3,4,6 and 7, see Section 7.5.1.
GWOM — Port G wired-OR mode
1 (set)
–
0 (clear) –
Port G [5:2] buffers configured for open-drain outputs.
Port G [5:2] buffers configured for normal CMOS outputs.
SP2R1 and SP2R0 — SPI2 clock rate selects
These two bits, along with the SP2R2 bit, select the SPI clock rate as shown in Table 7-1. Note
that SP2R2 is located in the SP2OPT register, and that its state on reset is zero.
7.6.2
7
SP2SR — SPI2 status register
Address
SPI2 status (SP2SR)
$004D
bit 7
bit 6
bit 5
bit 4
bit 3
bit 2
bit 1
bit 0
State
on reset
0
MODF2
0
0
0
0
0000 0000
SP2IF WCOL2
For a description of bits 4,6 and 7, see Section 7.5.2.
7.6.3
SP2DR — SPI2 data register
SPI2 data (SP2DR)
Address
bit 7
Bit 6
bit 5
bit 4
bit 3
bit 2
bit 1
bit 0
State
on reset
$004E
(bit 7)
(6)
(5)
(4)
(3)
(2)
(1)
(bit 0)
undeÞned
bit 1
bit 0
State
on reset
0
0
0000 0000
For a description of this register, see Section 7.5.3.
7.6.4
SP2OPT — SPI2 control options register
SPI2 control options (SP2DR)
Address
bit 7
bit 6
bit 5
bit 4
$004F
0
0
0
0
bit 3
bit 2
LSBF2 SP2R2
For a description of bits 2 and 3, see Section 7.5.4.
TPG
MC68HC11PH8
SERIAL PERIPHERAL INTERFACE
MOTOROLA
7-11
131
7
THIS PAGE INTENTIONALLY LEFT BLANK
TPG
MOTOROLA
7-12
SERIAL PERIPHERAL INTERFACE
MC68HC11PH8
132
8
TIMING SYSTEM
The MC68HC11PH8 has three timing modules: a 16-bit timer system (incorporating pulse
accumulator, RTI and COP), a pulse width modulation (PWM) system and an 8-bit modulus timing
system comprising timers A, B and C.
8.1
16-bit timer
The M68HC11 timing system is composed of several clock divider chains. The main clock divider
chain includes a 16-bit free-running counter, which is driven by a programmable prescaler. The main
timer’s programmable prescaler provides one of the four clocking rates to drive the 16-bit counter.
Two prescaler control bits select the prescale rate. The prescaler output divides the system clock by
1, 4, 8, or 16. Taps from this main clocking chain drive circuitry may be used to generate the slower
clocks used by the pulse accumulator, the real-time interrupt (RTI), the computer operating properly
(COP) watchdog subsystems and the LCD module. Refer to Figure 8-1 and Figure 8-2.
8
All main timer system activities can be referenced to the free-running counter. The counter begins
incrementing from $0000 as the MCU comes out of reset, and continues to the maximum count,
$FFFF. At the maximum count, the counter rolls over to $0000, sets an overflow flag and continues
to increment. As long as the MCU is running in a normal operating mode, there is no way to reset,
change or interrupt the counting, unless, for reduced power consumption and if the PLL is in
operation, the 16-bit counter is disabled under control of the T16EN bit (see Section 8.1.1.1). The
capture/compare subsystem features three input capture channels, four output compare channels
and one channel that can be selected to perform either input capture or output compare. Each of
the input capture functions has its own 16-bit input capture register (time capture latch) and each
of the output compare functions has its own 16-bit compare register. All timer functions, including
the timer overflow and RTI, have their own interrupt controls and separate interrupt vectors. See
Table 8-1 for related frequencies and periods.
The pulse accumulator contains an 8-bit counter and edge select logic. The pulse accumulator
can operate in either event counting mode or gated time accumulation mode. During event
counting mode, the pulse accumulator’s 8-bit counter increments when a specified edge is
detected on an input pin. During gated time accumulation mode, an internal clock source
(ST4XCK/28) increments the 8-bit counter while an input signal has a predetermined logic level.
TPG
MC68HC11PH8
TIMING SYSTEM
MOTOROLA
8-1
133
The real-time interrupt (RTI) is a programmable periodic interrupt circuit that permits pacing of the
execution of software routines by selecting one of four interrupt rates. It may be clocked by the
16-bit timer (ST4XCK/215) or by the underflow of 8-bit modulus timer A (CLK64), depending on
whether or not the PLL system is active (see Figure 8-1, Figure 8-2 and Section 8.1.5).
The COP watchdog clock input may be tapped off from the free-running counter chain
(ST4XCK/217), or may be the underflow of the 8-bit modulus timer A (CLK64/4), depending on
whether or not the PLL system is active (see Figure 8-1, Figure 8-2 and Section 8.1.6). The COP
automatically times out unless it is serviced within a specific time by a program reset sequence. If
the COP is allowed to time out, a reset is generated, which drives the RESET pin low to reset the
MCU and the external system (see Section 10).
The LCD module can drive up to four LCD segments, and may be clocked by the 16-bit timer
(ST4XCK/218), or by the underflow of the 8-bit modulus timer A (CLK64 or CLK64/8), depending on
whether or not the PLL system is active (see Figure 8-1, Figure 8-2 and Section 2).
Table 8-1 Timer resolution and capacity
4.0MHz
Control bits 1.0MHz
PR[1:0]
1000ns
1.0µs
00
65.536ms
4.0µs
01
262.14ms
8.0µs
10
524.29ms
16.0µs
11
1049 ms
8
8.0MHz
2.0MHz
500ns
500ns
32.768ms
2.0µs
131.07ms
4.0µs
262.14ms
8.0µs
524.29ms
Clock
12.0MHz
3.0MHz
333ns
333ns
21.845ms
1.333µs
87.381ms
2.667µs
174.76ms
5.333µs
349.53ms
16.0MHz
4.0MHz
250ns
250ns
16.384ms
1.0µs
65.536ms
2.0µs
131.07ms
4.0µs
262.14ms
ST4XCK
ST4XCK/4
4/ST4XCK
4/ST4XCK
218/ST4XCK
16/ST4XCK
220/ST4XCK
32/ST4XCK
221/ST4XCK
64/ST4XCK
222/ST4XCK
Crystal(1)
Clock
Period
Ð resolution
Ð overßow
Ð resolution
Ð overßow
Ð resolution
Ð overßow
Ð resolution
Ð overßow
(1) Crystal frequencies are valid only if the PLL is not active.
TPG
MOTOROLA
8-2
TIMING SYSTEM
MC68HC11PH8
134
8.1.1
Timer enable control
The 16-bit timer may be enabled or disabled under control of the T16EN bit in the PLL control
register.
8.1.1.1
PLLCR — PLL control register
Address
PLL control (PLLCR)
bit 7
$002E PLLON
bit 6
bit 5
bit 4
bit 3
bit 2
BCS
AUTO
BWC
VCOT
MCS
bit 1
bit 0
T16EN WEN
State
on reset
1010 1010
PLLON — PLL on (See Section 2.5.4.1)
1 (set)
–
Switch PLL on.
0 (clear) –
Switch PLL off.
BCS — Bus clock select (See Section 2.5.4.1)
1 (set)
–
0 (clear) –
VCOOUT output drives the clock circuit (4XCLK).
EXTALi drives the clock circuit (4XCLK).
AUTO — Automatic bandwidth control (See Section 2.5.4.1)
1 (set)
–
0 (clear) –
8
Automatic bandwidth control selected.
Manual bandwidth control selected.
BWC — Bandwidth control (See Section 2.5.4.1)
1 (set)
–
High bandwidth control selected.
0 (clear) –
Low bandwidth control selected.
VCOT — VCO test (Test mode only, see Section 2.5.4.1)
1 (set)
–
0 (clear) –
Loop filter operates as specified by AUTO and BWC.
Low bandwidth mode of the PLL filter is disabled.
MCS — Module clock select (See Section 2.5.4.1)
1 (set)
–
4XCLK is the source for the SCI and timer divider chain.
0 (clear) –
EXTALi is the source for the SCI and timer divider chain.
TPG
MC68HC11PH8
TIMING SYSTEM
MOTOROLA
8-3
135
T16EN — 16-bit timer clock enable
1 (set)
–
16-bit timer clock enabled.
0 (clear) –
16-bit timer clock disabled.
Power consumption may be reduced by disabling the 16-bit timer clock. This bit cannot be cleared
whilst VDDSYN is low, as then the 16-bit timer provides the clock source for the COP and RTI.
When VDDSYN is high, the 8-bit modulus timer A supplies the clock source for the COP and RTI
functions, which are therefore independent from the 16-bit timer clock. Reset sets this bit.
WEN — WAIT enable (See Section 2.5.4.1)
1 (set)
–
0 (clear) –
8.1.2
Low-power WAIT mode selected (PLL set to ‘idle’ in WAIT mode).
Do not alter the 4XCLK during WAIT mode.
Timer structure
The timer functions share I/O with all eight pins of port A:
Pin
PA0
PA1
PA2
PA3
PA4
PA5
PA6
PA7
8
Alternate function
IC3
IC2
IC1
OC5 and/or OC1, or IC4
OC4 and/or OC1
OC3 and/or OC1
OC2 and/or OC1
PAI and/or OC1
Figure 8-3 shows the capture/compare system block diagram. The port A pin control block
includes logic for timer functions and for general-purpose I/O. For pins PA3, PA2, PA1 and PA0,
this block contains both the edge-detection logic and the control logic that enables the selection
of which edge triggers an input capture. The digital level on PA[3:0] can be read at any time (read
PORTA register), even if the pin is being used for the input capture function. Pins PA[6:3] are used
either for general-purpose I/O, or as output compare pins. When one of these pins is being used
for an output compare function, it cannot be written directly as if it were a general-purpose output.
Each of the output compare functions (OC[5:2]) is related to one of the port A output pins. Output
compare 1 (OC1) has extra control logic, allowing it optional control of any combination of the
PA[7:3] pins. The PA7 pin can be used as a general-purpose I/O pin, as an input to the pulse
accumulator or as an OC1 output pin.
TPG
MOTOROLA
8-4
TIMING SYSTEM
MC68HC11PH8
136
Bus
clock
select
1
PLL
0
4XCLK
E clock
÷4
Internal bus clock
PH2 (for CPU, PWM,
A/D and memory)
BCS
Prescaler
÷ 2, 4, 8,16, 32, 64, 128
SPI
SPR[2:0]
1
Crystal
oscillator
EXTALi
0
Baud
Module
clock
select
SCI receiver clock
÷ 1, 2, 3, 4,É, 8191
÷2
÷ 16
SBR[12:0]
SCI transmitter clock
(baud rate)
ST4XCK
MCS
÷4
TOF
TCNT
Prescaler
÷ 1, 4, 8, 16
PR[1:0]
Prescaler
÷ 1, 4, 8
CSA[2:0]
IC/OC
÷ 26
8-bit modulus timer A
÷2
Pulse accumulator
Prescaler
CLK64
÷ 1, 2, 4, 64
Real time interrupt
RTR[1:0]
8
LCDCK
0
÷4
÷2
1
LCD
clock
select
LCD
Prescaler
÷ 1, 4, 16, 64
CR[1:0]
Set
Q
Set
Q
FF1
Clear COP timer
Reset
FF2
Q
+
Reset
Q
Force COP reset
System reset
Figure 8-1 Timer clock divider chains (PLL enabled — VDDSYN high)
TPG
MC68HC11PH8
TIMING SYSTEM
MOTOROLA
8-5
137
Crystal
oscillator
EXTALi ≡ ST4XCK
E clock
÷4
Internal bus clock
PH2 (for CPU, PWM,
A/D and memory)
Prescaler
÷ 2, 4, 8,16, 32, 64, 128
SPI
SPR[2:0]
Baud
SCI receiver clock
÷ 1, 2, 3, 4,É, 8191
÷2
÷ 16
SBR[12:0]
CLK64
÷2
8-bit modulus timer A
LCDCK
0
÷
SCI transmitter clock
(baud rate)
218
1
LCD
clock
select
LCD
÷4
TOF
TCNT
Prescaler
÷ 1, 4, 8, 16
PR[1:0]
8
IC/OC
÷ 26
Pulse accumulator
÷ 213
Prescaler
÷ 1, 2, 4, 8
Real time interrupt
RTR[1:0]
÷4
Prescaler
÷ 1, 4, 16, 64
CR[1:0]
Set
Q
Set
Q
FF1
Clear COP timer
Reset
FF2
Q
+
Reset
Q
Force COP reset
System reset
Figure 8-2 Timer clock divider chains (PLL disabled — VDDSYN low)
TPG
MOTOROLA
8-6
TIMING SYSTEM
MC68HC11PH8
138
Prescaler
÷ 1, 4, 8, 16
ST4XCK/4
PR[1:0]
TCNT (hi) TCNT (lo)
TOI
16-bit
free running counter
TOF
&
9
Note
16-bit timer bus
CFORC
Force O/P
compare
16-bit comparator EQ
To pulse accumulator
OC1I
&
8
PA7/
OC1/
PAI
OC1F
+
TOC1 (hi) TOC1 (lo)
Bit 7
FOC1
OC2I
&
16-bit comparator
EQ
7
OC2F
+
TOC2 (hi) TOC2 (lo)
Bit 6
PA6/
OC2/
OC1
Bit 5
PA5/
OC3/
OC1
Bit 4
PA4/
OC4/
OC1
Bit 3
PA3/
OC5/
OC1/
IC4
Bit 2
PA2/
IC1
Bit 1
PA1/
IC2
Bit 0
PA0/
IC3
FOC2
OC3I
&
16-bit comparator
EQ
6
OC3F
+
TOC3 (hi) TOC3 (lo)
FOC3
OC4I
&
16-bit comparator
EQ
5
OC4F
+
TOC4 (hi) TOC4 (lo)
FOC4
I4/O5I
&
TI4/O5 (hi) TI4/O5 (lo)
16-bit latch
I4/O5F
+
FOC5
CLK
IC4
&
TIC1 (hi)
CLK
8
IC1I
I4/O5
16-bit latch
4
OC5
16-bit comparator EQ
3
IC1F
TIC1 (lo)
IC2I
&
16-bit latch
TIC2 (hi)
CLK
2
IC2F
TIC2 (lo)
IC3I
&
16-bit latch
TIC3 (hi)
CLK
TIC3 (lo)
1
IC3F
TFLG1
TMSK1
Port A
status
ßags
interrupt
enables
pin
controlà
Pins/
functions
Interrupt requests 1Ð9 (these are further qualiÞed by the I-bit in the CCR)
à Port A pin actions are controlled by OC1M, OC1D, PACTL, TCTL1 and TCTL2 registers
Figure 8-3 Capture/compare block diagram
TPG
MC68HC11PH8
TIMING SYSTEM
MOTOROLA
8-7
139
8.1.3
Input capture
The input capture function records the time an external event occurs by latching the value of the
free-running counter when a selected edge is detected at the associated timer input pin. Software
can store latched values and use them to compute the periodicity and duration of events. For
example, by storing the times of successive edges of an incoming signal, software can determine
the period and pulse width of a signal. To measure period, two successive edges of the same
polarity are captured. To measure pulse width, two alternate polarity edges are captured.
In most cases, input capture edges are asynchronous with respect to the internal timer counter,
which is clocked relative to an internal clock (PH2). These asynchronous capture requests are
synchronized with PH2 so that latching occurs on the opposite half cycle of PH2 from when the
timer counter is being incremented. This synchronization process introduces a delay from when
the edge occurs to when the counter value is detected. Because these delays cancel out when
the time between two edges is being measured, the delay can be ignored. When an input capture
is being used with an output compare, there is a similar delay between the actual compare point
and when the output pin changes state.
The control and status bits that implement the input capture functions are contained in the PACTL,
TCTL2, TMSK1, and TFLG1 registers.
8
To configure port A bit 3 as an input capture, clear the DDA3 bit of the DDRA register. Note that
this bit is cleared out of reset. To enable PA3 as the fourth input capture, set the I4/O5 bit in the
PACTL register. Otherwise, PA3 is configured as a fifth output compare out of reset, with bit I4/O5
being cleared. If the DDA3 bit is set (configuring PA3 as an output), and IC4 is enabled, then writes
to PA3 cause edges on the pin to result in input captures. Writing to TI4/O5 has no effect when the
TI4/O5 register is acting as IC4.
TPG
MOTOROLA
8-8
TIMING SYSTEM
MC68HC11PH8
140
8.1.3.1
TCTL2 — Timer control register 2
Address
Timer control 2 (TCTL2)
bit 7
bit 6
bit 5
bit 4
bit 3
bit 2
bit 1
bit 0
State
on reset
$0021 EDG4B EDG4A EDG1B EDG1A EDG2B EDG2A EDG3B EDG3A 0000 0000
Use the control bits of this register to program input capture functions to detect a particular edge
polarity on the corresponding timer input pin. Each of the input capture functions can be
independently configured to detect rising edges only, falling edges only, any edge (rising or falling),
or to disable the input capture function. The input capture functions operate independently of each
other and can capture the same TCNT value if the input edges are detected within the same timer
count cycle.
EDGxB and EDGxA — Input capture edge control
EDGxB EDGxA
ConÞguration
0
0
ICx disabled
0
1
ICx captures on rising edges only
1
0
ICx captures on falling edges only
1
1
ICx captures on any edge
There are four pairs of these bits. Each pair is cleared by reset and must be encoded to configure
the corresponding input capture edge detector circuit. IC4 functions only if the I4/O5 bit in the
PACTL register is set.
8
TPG
MC68HC11PH8
TIMING SYSTEM
MOTOROLA
8-9
141
8.1.3.2
TIC1–TIC3 — Timer input capture registers
bit 1
bit 0
State
on reset
Address
bit 7
bit 6
bit 5
bit 4
bit 3
bit 2
Timer input capture 1 (TIC1) high
$0010
(bit 15)
(14)
(13)
(12)
(11)
(10)
(9)
(bit 8)
undeÞned
Timer input capture 1 (TIC1) low
$0011
(bit 7)
(6)
(5)
(4)
(3)
(2)
(1)
(bit 0)
undeÞned
Timer input capture 2 (TIC2) high
$0012
(bit 15)
(14)
(13)
(12)
(11)
(10)
(9)
(bit 8)
undeÞned
Timer input capture 2 (TIC2) low
$0013
(bit 7)
(6)
(5)
(4)
(3)
(2)
(1)
(bit 0)
undeÞned
Timer input capture 3 (TIC3) high
$0014
(bit 15)
(14)
(13)
(12)
(11)
(10)
(9)
(bit 8)
undeÞned
Timer input capture 3 (TIC3) low
$0015
(bit 7)
(6)
(5)
(4)
(3)
(2)
(1)
(bit 0)
undeÞned
When an edge has been detected and synchronized, the 16-bit free-running counter value is
transferred into the input capture register pair as a single 16-bit parallel transfer. Timer counter
value captures and timer counter incrementing occur on opposite half-cycles of the phase 2 clock
so that the count value is stable whenever a capture occurs. Input capture values can be read from
a pair of 8-bit read-only registers. A read of the high-order byte of an input capture register pair
inhibits a new capture transfer for one bus cycle. If a double-byte read instruction, such as LDD,
is used to read the captured value, coherency is assured. When a new input capture occurs
immediately after a high-order byte read, transfer is delayed for an additional cycle but the value
is not lost.
8
The TICx registers are not affected by reset.
8.1.3.3
TI4/O5 — Timer input capture 4/output compare 5 register
Address
bit 7
bit 6
bit 5
bit 4
bit 3
bit 2
bit 1
bit 0
State
on reset
Capture 4/compare 5 (TI4/O5) high
$001E (bit 15)
(14)
(13)
(12)
(11)
(10)
(9)
(bit 8) 1111 1111
Capture 4/compare 5 (TI4/O5) low
$001F
(6)
(5)
(4)
(3)
(2)
(1)
(bit 0) 1111 1111
(bit 7)
Use TI4/O5 as either an input capture register or an output compare register, depending on the
function chosen for the PA3 pin. To enable it as an input capture pin, set the I4/O5 bit in the pulse
accumulator control register (PACTL) to logic level one. To use it as an output compare register,
set the I4/O5 bit to a logic level zero. Refer to Section 8.1.8.1.
The TI4/O5 register pair resets to ones ($FFFF).
TPG
MOTOROLA
8-10
TIMING SYSTEM
MC68HC11PH8
142
8.1.4
Output compare
Use the output compare (OC) function to program an action to occur at a specific time — when
the 16-bit counter reaches a specified value. For each of the five output compare functions, there
is a separate 16-bit compare register and a dedicated 16-bit comparator. The value in the compare
register is compared to the value of the free-running counter on every bus cycle. When the
compare register matches the counter value, an output compare status flag is set. The flag can be
used to initiate the automatic actions for that output compare function.
To produce a pulse of a specific duration, write a value to the output compare register that
represents the time the leading edge of the pulse is to occur. The output compare circuit is
configured to set the appropriate output either high or low, depending on the polarity of the pulse
being produced. After a match occurs, the output compare register is reprogrammed to change
the output pin back to its inactive level at the next match. A value representing the width of the
pulse is added to the original value, and then written to the output compare register. Because the
pin state changes occur at specific values of the free-running counter, the pulse width can be
controlled accurately at the resolution of the free-running counter, independent of software
latency. To generate an output signal of a specific frequency and duty cycle, repeat this
pulse-generating procedure.
There are four 16-bit read/write output compare registers: TOC1, TOC2, TOC3, and TOC4, and
the TI4/O5 register, which functions under software control as either IC4 or OC5. Each of the OC
registers is set to $FFFF on reset. A value written to an OC register is compared to the
free-running counter value during each E clock cycle. If a match is found, the particular output
compare flag is set in timer interrupt flag register 1 (TFLG1). If that particular interrupt is enabled
in the timer interrupt mask register 1 (TMSK1), an interrupt is generated. In addition to an interrupt,
a specified action can be initiated at one or more timer output pins. For OC[5:2], the pin action is
controlled by pairs of bits (OMx and OLx) in the TCTL1 register. The output action is taken on each
successful compare, regardless of whether or not the OCxF flag in the TFLG1 register was
previously cleared.
8
OC1 is different from the other output compares in that a successful OC1 compare can affect any
or all five of the OC pins. The OC1 output action taken when a match is found is controlled by two
8-bit registers with three bits unimplemented: the output compare 1 mask register, OC1M, and the
output compare 1 data register, OC1D. OC1M specifies which port A outputs are to be used, and
OC1D specifies what data is placed on these port pins.
TPG
MC68HC11PH8
TIMING SYSTEM
MOTOROLA
8-11
143
8.1.4.1
TOC1–TOC4 — Timer output compare registers
State
on reset
Address
bit 7
bit 6
bit 5
bit 4
bit 3
bit 2
bit 1
bit 0
Timer output compare 1 (TOC1) high
$0016
(bit 15)
(14)
(13)
(12)
(11)
(10)
(9)
(bit 8) 1111 1111
Timer output compare 1 (TOC1) low
$0017
(bit 7)
(6)
(5)
(4)
(3)
(2)
(1)
(bit 0) 1111 1111
Timer output compare 2 (TOC2) high
$0018
(bit 15)
(14)
(13)
(12)
(11)
(10)
(9)
(bit 8) 1111 1111
Timer output compare 2 (TOC2) low
$0019
(bit 7)
(6)
(5)
(4)
(3)
(2)
(1)
(bit 0) 1111 1111
Timer output compare 3 (TOC3) high
$001A (bit 15)
(14)
(13)
(12)
(11)
(10)
(9)
(bit 8) 1111 1111
Timer output compare 3 (TOC3) low
$001B
(bit 7)
(6)
(5)
(4)
(3)
(2)
(1)
(bit 0) 1111 1111
Timer output compare 4 (TOC4) high
$001C (bit 15)
(14)
(13)
(12)
(11)
(10)
(9)
(bit 8) 1111 1111
Timer output compare 4 (TOC4) low
$001D
(6)
(5)
(4)
(3)
(2)
(1)
(bit 0) 1111 1111
(bit 7)
All output compare registers are 16-bit read-write. Each is initialized to $FFFF at reset. If an output
compare register is not used for an output compare function, it can be used as a storage location.
A write to the high-order byte of an output compare register pair inhibits the output compare
function for one bus cycle. This inhibition prevents inappropriate subsequent comparisons.
Coherency requires a complete 16-bit read or write. However, if coherency is not needed, byte
accesses can be used.
8
For output compare functions, write a comparison value to output compare registers TOC1–TOC4
and TI4/O5. When TCNT value matches the comparison value, specified pin actions occur.
All TOCx register pairs reset to ones ($FFFF).
8.1.4.2
CFORC — Timer compare force register
Timer compare force (CFORC)
Address
bit 7
bit 6
bit 5
bit 4
bit 3
bit 2
bit 1
bit 0
State
on reset
$000B
FOC1
FOC2
FOC3
FOC4
FOC5
0
0
0
0000 0000
The CFORC register allows forced early compares. FOC[1:5] correspond to the five output
compares. These bits are set for each output compare that is to be forced. The action taken as a
result of a forced compare is the same as if there were a match between the OCx register and the
free-running counter, except that the corresponding interrupt status flag bits are not set. The
forced channels trigger their programmed pin actions to occur at the next timer count transition
after the write to CFORC.
The CFORC bits should not be used on an output compare function that is programmed to toggle
its output on a successful compare because a normal compare that occurs immediately before or
after the force can result in an undesirable operation.
TPG
MOTOROLA
8-12
TIMING SYSTEM
MC68HC11PH8
144
FOC[1:5] — Force output compares
1 (set)
–
0 (clear) –
A forced output compare action will occur on the specified pin.
No action.
Bits [2:0] — Not implemented; always read zero
8.1.4.3
OC1M — Output compare 1 mask register
Address
Output compare 1 mask (OC1M)
bit 7
bit 6
bit 5
bit 4
bit 3
$000C OC1M7 OC1M6 OC1M5 OC1M4 OC1M3
bit 2
bit 1
bit 0
State
on reset
0
0
0
0000 0000
Use OC1M with OC1 to specify the bits of port A that are affected by a successful OC1 compare.
The bits of the OC1M register correspond to PA7–PA3.
OC1M[7:3] — Output compare masks for OC1
1 (set)
–
0 (clear) –
OC1 is configured to control the corresponding pin of port A.
OC1 will not affect the corresponding port A pin.
Bits [2:0] — Not implemented; always read zero.
8.1.4.4
8
OC1D — Output compare 1 data register
Address
Output compare 1 data (OC1D)
bit 7
bit 6
bit 5
bit 4
bit 3
$000D OC1D7 OC1D6 OC1D5 OC1D4 OC1D3
bit 2
bit 1
bit 0
State
on reset
0
0
0
0000 0000
Use this register with OC1 to specify the data that is to be written to the affected pin of port A after
a successful OC1 compare. When a successful OC1 compare occurs, a data bit in OC1D is written
to the corresponding pin of port A for each bit that is set in OC1M.
OC1D[7:3] — Output compare data for OC1
If OC1Mx is set, data in OC1Dx is output to port A pin x on successful OC1 compares.
Bits [2:0] — Not implemented; always read zero
TPG
MC68HC11PH8
TIMING SYSTEM
MOTOROLA
8-13
145
8.1.4.5
TCNT — Timer counter register
Address
bit 7
bit 6
bit 5
bit 4
bit 3
bit 2
bit 1
bit 0
State
on reset
Timer count (TCNT) high
$000E (bit 15)
(14)
(13)
(12)
(11)
(10)
(9)
(bit 8) 0000 0000
Timer count (TCNT) low
$000F
(6)
(5)
(4)
(3)
(2)
(1)
(bit 0) 0000 0000
(bit 7)
The 16-bit read-only TCNT register contains the prescaled value of the 16-bit timer. A full counter
read addresses the more significant byte (MSB) first. A read of this address causes the less
significant byte (LSB) to be latched into a buffer for the next CPU cycle so that a double-byte read
returns the full 16-bit state of the counter at the time of the MSB read cycle.
TCNT resets to $0000.
8.1.4.6
TCTL1 — Timer control register 1
Timer control 1 (TCTL1)
Address
bit 7
bit 6
bit 5
bit 4
bit 3
bit 2
bit 1
bit 0
State
on reset
$0020
OM2
OL2
OM3
OL3
OM4
OL4
OM5
OL5
0000 0000
The bits of this register specify the action taken as a result of a successful OCx compare.
8
OM[2:5] — Output mode
OL[2:5] — Output level
OMx
0
0
1
1
OLx
0
1
0
1
Action taken on successful compare
Timer disconnected from OCx pin logic
Toggle OCx output line
Clear OCx output line to 0
Set OCx output line to 1
These control bit pairs are encoded to specify the action taken after a successful OCx compare.
OC5 functions only if the I4/O5 bit in the PACTL register is clear.
TPG
MOTOROLA
8-14
TIMING SYSTEM
MC68HC11PH8
146
8.1.4.7
TMSK1 — Timer interrupt mask register 1
Timer interrupt mask 1 (TMSK1)
Address
bit 7
bit 6
bit 5
bit 4
bit 3
bit 2
bit 1
bit 0
State
on reset
$0022
OC1I
OC2I
OC3I
OC4I
I4/O5I
IC1I
IC2I
IC3I
0000 0000
Use this 8-bit register to enable or inhibit the timer input capture and output compare interrupts.
Note:
Bits in TMSK1 correspond bit for bit with flag bits in TFLG1. Ones in TMSK1 enable the
corresponding interrupt sources.
OC1I–OC4I — Output compare x interrupt enable
1 (set)
–
OCx interrupt is enabled.
0 (clear) –
OCx interrupt is disabled.
If the OCxI enable bit is set when the OCxF flag bit is set, a hardware interrupt sequence is requested.
I4/O5I — Input capture 4/output compare 5 interrupt enable
1 (set)
–
IC4/OC5 interrupt is enabled.
0 (clear) –
IC4/OC5 interrupt is disabled.
8
When I4/O5 in PACTL is set, I4/O5I is the input capture 4 interrupt enable bit.
When I4/O5 in PACTL is zero, I4/O5I is the output compare 5 interrupt enable bit.
IC1I–IC3I — Input capture x interrupt enable
1 (set)
–
ICx interrupt is enabled.
0 (clear) –
ICx interrupt is disabled.
If the ICxI enable bit is set when the ICxF flag bit is set, a hardware interrupt sequence is requested.
TPG
MC68HC11PH8
TIMING SYSTEM
MOTOROLA
8-15
147
8.1.4.8
TFLG1 — Timer interrupt flag register 1
Timer interrupt ßag 1 (TFLG1)
Address
bit 7
bit 6
bit 5
$0023
OC1F
OC2F
OC3F
bit 4
bit 3
OC4F I4/O5F
bit 2
bit 1
bit 0
State
on reset
IC1F
IC2F
IC3F
0000 0000
Bits in this register indicate when timer system events have occurred. Coupled with the bits of
TMSK1, the bits of TFLG1 allow the timer subsystem to operate in either a polled or interrupt
driven system. Clear flags by writing a one to the corresponding bit position(s).
Note:
Bits in TFLG1 correspond bit for bit with flag bits in TMSK1. Ones in TMSK1 enable the
corresponding interrupt sources.
OC1F–OC4F — Output compare x flag
1 (set)
–
0 (clear) –
Counter has reached the preset output compare x value.
Counter has not reached the preset output compare x value.
These flags are set each time the counter matches the corresponding output compare x values.
I4/O5F — Input capture 4/output compare 5 flag
8
Set by IC4 or OC5, depending on the function enabled by I4/O5 bit in PACTL
IC1F–IC3F — Input capture x flag
1 (set)
–
0 (clear) –
Selected edge has been detected on corresponding port pin.
Selected edge has not been detected on corresponding port pin.
These flags are set each time a selected active edge is detected on the ICx input line
TPG
MOTOROLA
8-16
TIMING SYSTEM
MC68HC11PH8
148
8.1.4.9
TMSK2 — Timer interrupt mask register 2
Timer interrupt mask 2 (TMSK2)
Address
bit 7
bit 6
bit 5
bit 4
bit 3
bit 2
bit 1
bit 0
State
on reset
$0024
TOI
RTII
PAOVI
PAII
0
0
PR1
PR0
0000 0000
Use this 8-bit register to enable or inhibit timer overflow and real-time interrupts. The timer
prescaler control bits are included in this register.
Note:
Bits in TMSK2 correspond bit for bit with flag bits in TFLG2. Ones in TMSK2 enable the
corresponding interrupt sources.
TOI — Timer overflow interrupt enable
1 (set)
–
0 (clear) –
Timer overflow interrupt requested when TOF is set.
TOF interrupts disabled.
RTII — Real-time interrupt enable (refer to Section 8.1.5)
1 (set)
–
0 (clear) –
Real time interrupt requested when RTIF is set.
Real time interrupts disabled.
8
PAOVI — Pulse accumulator overflow interrupt enable (refer to Section 8.1.8)
PAII — Pulse accumulator input edge interrupt enable (refer to Section 8.1.8)
Bits [3, 2] — Not implemented; always read zero.
PR[1:0] — Timer prescaler select
PR[1:0]
00
01
10
11
Prescaler
1
4
8
16
These bits are used to select the prescaler divide-by ratio. In normal modes, PR[1:0] can only be
written once, and the write must be within 64 cycles after reset. See Table 8-1 for specific timing
values.
TPG
MC68HC11PH8
TIMING SYSTEM
MOTOROLA
8-17
149
8.1.4.10
TFLG2 — Timer interrupt flag register 2
Timer interrupt ßag 2 (TFLG2)
Address
bit 7
bit 6
bit 5
$0025
TOF
RTIF PAOVF
bit 4
bit 3
bit 2
bit 1
bit 0
State
on reset
PAIF
0
0
0
0
0000 0000
Bits in this register indicate when certain timer system events have occurred. Coupled with the
four high-order bits of TMSK2, the bits of TFLG2 allow the timer subsystem to operate in either a
polled or interrupt driven system. Clear flags by writing a one to the corresponding bit position(s).
Note:
Bits in TFLG2 correspond bit for bit with flag bits in TMSK2. Ones in TMSK2 enable the
corresponding interrupt sources.
TOF — Timer overflow interrupt flag
1 (set)
–
0 (clear) –
TCNT has overflowed from $FFFF to $0000.
No timer overflow has occurred.
RTIF — Real time (periodic) interrupt flag (refer to Section 8.1.5)
1 (set)
8
–
0 (clear) –
RTI period has elapsed.
RTI flag has been cleared.
PAOVF — Pulse accumulator overflow interrupt flag (refer to Section 8.1.8)
PAIF — Pulse accumulator input edge interrupt flag (refer to Section 8.1.8.)
Bits [3:0] — Not implemented; always read zero
TPG
MOTOROLA
8-18
TIMING SYSTEM
MC68HC11PH8
150
8.1.5
Real-time interrupt
The real-time interrupt (RTI) feature, used to generate hardware interrupts at a fixed periodic rate,
has two possible clock sources. When the PLL clock generation is not used (VDDSYN low), the
RTI function is clocked by the 16-bit free-running counter (ST4XCK/215). When the PLL clock
generation is used (VDDSYN high), the RTI clock source is the underflow of the 8-bit modulus
timer A (CLK64). This ensures that the RTI interrupt rate is unaffected by changes made to the
bus speed by the PLL circuit. See Figure 8-1 and Figure 8-2. The RTI clock rate is controlled and
configured by two bits (RTR1 and RTR0) in the pulse accumulator control (PACTL) register. The
different rates available are a product of the source frequency and the value of bits RTR[1:0]. If
VDDSYN is low, the source frequency, ST4XCK/215, can be divided by 1,2,4 or 8. If VDDSYN is
high, the source frequency, CLK64, can be divided by 1,2,4 or 64. Refer to Table 8-2 and Table
8-3 which show examples of periodic real-time interrupt rates. The RTII bit in the TMSK2 register
enables the interrupt capability.
Table 8-2 RTI periodic rates (PLL disabled)
RTR[1:0]
00
01
10
11
ST4XCK = 12MHz
2.731ms
5.461ms
10.923ms
21.845ms
ST4XCK = 8MHz
4.096ms
8.192ms
16.384ms
32.768ms
ST4XCK = 4MHz
8.192ms
16.384ms
32.768ms
65.536ms
ST4XCK = xMHz
215/ST4XCK
216/ST4XCK
217/ST4XCK
218/ST4XCK
8
Table 8-3 RTI periodic rates (PLL enabled)
RTR[1:0]
00
01
10
11
Note:
EXTALi = 640kHz EXTALi = 32.768kHz
0.4ms
7.81ms
0.8ms
15.63ms
1.6ms
31.25ms
25.6ms
500ms
EXTALi = 32kHz
8.0ms
16.0ms
32.0ms
512ms
EXTALi = xkHz
28/EXTALi
29/EXTALi
210/EXTALi
214/EXTALi
The values in Table 8-3 assume that the 8-bit modulus timer is loaded to give an
EXTALi/28 prescaler value. Other prescaler values are possible, in the range EXTALi/4
to EXTALi/4080 (see Section 8.3.1).
Either clock source causes the time between successive RTI timeouts to be a constant that is
independent of the software latency associated with flag clearing and service. For this reason, an
RTI period starts from the previous timeout, not from when RTIF is cleared.
Every timeout causes the RTIF bit in TFLG2 to be set, and if RTII is set, an interrupt request is
generated. After reset, one entire RTI period elapses before the RTIF flag is set for the first time.
Refer to the TMSK2, TFLG2, and PACTL registers.
TPG
MC68HC11PH8
TIMING SYSTEM
MOTOROLA
8-19
151
8.1.5.1
TMSK2 — Timer interrupt mask register 2
Timer interrupt mask 2 (TMSK2)
Address
bit 7
bit 6
bit 5
bit 4
bit 3
bit 2
bit 1
bit 0
State
on reset
$0024
TOI
RTII
PAOVI
PAII
0
0
PR1
PR0
0000 0000
This register contains the real-time interrupt enable bit.
Note:
Bits in TMSK2 correspond bit for bit with flag bits in TFLG2. Ones in TMSK2 enable the
corresponding interrupt sources.
TOI — Timer overflow interrupt enable (refer to Section 8.1.4.9)
1 (set)
–
0 (clear) –
Timer overflow interrupt requested when TOF is set.
TOF interrupts disabled.
RTII — Real-time interrupt enable
1 (set)
–
0 (clear) –
8
Real time interrupt requested when RTIF is set.
Real time interrupts disabled.
PAOVI — Pulse accumulator overflow interrupt enable (refer to Section 8.1.8)
PAII — Pulse accumulator input edge (refer to Section 8.1.8)
Bits[3, 2] — Not implemented; always reads zero
PR[1, 0] — Timer prescaler select (refer to Section 8.1.4.9)
TPG
MOTOROLA
8-20
TIMING SYSTEM
MC68HC11PH8
152
8.1.5.2
TFLG2 — Timer interrupt flag register 2
Timer interrupt ßag 2 (TFLG2)
Address
bit 7
bit 6
bit 5
$0025
TOF
RTIF PAOVF
bit 4
bit 3
bit 2
bit 1
bit 0
State
on reset
PAIF
0
0
0
0
0000 0000
Bits of this register indicate the occurrence of timer system events. Coupled with the four
high-order bits of TMSK2, the bits of TFLG2 allow the timer subsystem to operate in either a polled
or interrupt driven system. Clear flags by writing a one to the corresponding bit position(s).
Note:
Bits in TFLG2 correspond bit for bit with flag bits in TMSK2. Ones in TMSK2 enable the
corresponding interrupt sources.
TOF — Timer overflow interrupt flag (refer to Section 8.1.4.10)
1 (set)
–
0 (clear) –
TCNT has overflowed from $FFFF to $0000.
No timer overflow has occurred.
RTIF — Real-time interrupt flag
1 (set)
–
0 (clear) –
RTI period has elapsed.
8
RTI flag has been cleared.
The RTIF status bit is automatically set to one at the end of every RTI period.
PAOVF — Pulse accumulator overflow interrupt flag (refer to Section 8.1.8)
PAIF — Pulse accumulator input edge interrupt flag (refer to Section 8.1.8)
Bits [3:0] — Not implemented; always read zero
TPG
MC68HC11PH8
TIMING SYSTEM
MOTOROLA
8-21
153
8.1.5.3
PACTL — Pulse accumulator control register
Pulse accumulator control (PACTL)
Address
bit 7
$0026
0
bit 6
bit 5
bit 4
PAEN PAMOD PEDGE
State
on reset
bit 3
bit 2
bit 1
bit 0
0
I4/O5
RTR1
RTR0 0000 0000
Bits RTR[1:0] of this register select the rate for the RTI system. The remaining bits control the
pulse accumulator and IC4/OC5 functions.
Bits [7, 3] — Not implemented; always read zero
PAEN — Pulse accumulator system enable (refer to Section 8.1.8)
1 (set)
–
Pulse accumulator enabled.
0 (clear) –
Pulse accumulator disabled.
PAMOD — Pulse accumulator mode (refer to Section 8.1.8)
1 (set)
–
0 (clear) –
8
Gated time accumulation mode.
Event counter mode.
PEDGE — Pulse accumulator edge control (refer to Section 8.1.8)
This bit has different meanings depending on the state of the PAMOD bit.
I4/O5 — Input capture 4/output compare 5 (refer to Section 8.1.8)
1 (set)
–
0 (clear) –
Input capture 4 function is enabled (no OC5).
Output compare 5 function is enabled (no IC4).
RTR[1:0] — RTI interrupt rate select
These two bits determine the rate at which the RTI system requests interrupts. The RTI system is
driven either by CLK64 or by an ST4XCK/215 clock rate that is compensated so it is independent
of the timer prescaler. These two control bits select an additional division factor. Refer to Table 8-2
and Table 8-3.
TPG
MOTOROLA
8-22
TIMING SYSTEM
MC68HC11PH8
154
8.1.6
Computer operating properly watchdog function
There are two possible clock sources for the COP function (see Figure 8-1 and Figure 8-2). When
PLL clock generation is not used (VDDSYN low), the clocking chain for the COP function is tapped
off from the main timer divider chain (ST4XCK/217). When the PLL clock generation is used
(VDDSYN high), the COP function is clocked by the underflow of the 8-bit modulus timer A
(CLK64/4). The CR[1:0] bits in the OPTION register and the NOCOP bit in the CONFIG register
control and configure the COP function. One additional register, COPRST, is used to arm and
clear the COP watchdog reset system. Refer to Section 10 for a more detailed discussion of the
COP function.
8.1.7
LCD module
There are three possible clock sources for the LCD module, under control of the LCDCK bit and
depending on the state of VDDSYN. When LCDCK = 0, the LCD module is clocked by the output
of 8-bit modulus timer A (CLK64). When LCDCK = 1, the LCD module is clocked by CLK64/8 if
PLL clock generation is used (VDDSYN high), and by ST4XCK/218 if PLL clock generation is not
used (VDDSYN low). Refer to Figure 8-1, Figure 8-2 and Section 2.12.
8.1.8
Pulse accumulator
8
The MC68HC11PH8 has an 8-bit counter that can be configured to operate either as a simple
event counter, or for gated time accumulation, depending on the state of the PAMOD bit in the
PACTL register. Refer to the pulse accumulator block diagram, Figure 8-4.
In the event counting mode, the 8-bit counter is clocked to increasing values by an external pin.
The maximum clocking rate for the external event counting mode is the E clock divided by two. In
gated time accumulation mode, a free-running ST4XCK/28 signal drives the 8-bit counter, but only
while the external PAI pin is activated. Refer to Table 8-4. The pulse accumulator counter can be
read or written at any time.
Table 8-4 Pulse accumulator timing
Crystal frequency(1)
4.0 MHz
8.0 MHz
12.0 MHz
16.0 MHz
ST4XCK/4 clock Cycle time 28/ST4XCK PACNT overßow
1.0 MHz
1000 ns
64 µs
16.384 ms
2.0 MHz
500 ns
32 µs
8.192 ms
3.0 MHz
333 ns
21.33 µs
5.461 ms
4.0 MHz
250 ns
16.0 µs
4.096 ms
(1) Crystal frequency values are only valid if the PLL is not active.
TPG
MC68HC11PH8
TIMING SYSTEM
MOTOROLA
8-23
155
TOF
RTIF
TFLG2
PAOVF
&
PAIF
0
TOI
0
TMSK2
0
Disable ßag setting
ST4XCK/28 clock
(from main timer)
Interrupt
requests
RTII
0
PAOVI
PAII
1
&
2
0
0
PR1
PR0
&
Overßow
2:1
MUX
PA7/
OC1/
PAI
Clock
Input buffer
and edge detector
PACNT
Enable
RTR0
I4/O5
RTR1
PEDGE
0
PAMOD
From
OC1
PAEN
8
0
Output buffer
PACTL
From
DDRA7
Internal data bus
Figure 8-4 Pulse accumulator block diagram
Pulse accumulator control bits are located within the PACTL, TMSK2 and TFLG2 registers, as
described in the following paragraphs.
TPG
MOTOROLA
8-24
TIMING SYSTEM
MC68HC11PH8
156
8.1.8.1
PACTL — Pulse accumulator control register
Pulse accumulator control (PACTL)
Address
bit 7
$0026
0
bit 6
bit 5
bit 4
PAEN PAMOD PEDGE
State
on reset
bit 3
bit 2
bit 1
bit 0
0
I4/O5
RTR1
RTR0 0000 0000
Four of this register’s bits control an 8-bit pulse accumulator system. Another bit enables either the
OC5 function or the IC4 function, while two other bits select the rate for the real-time interrupt system.
Bits [7, 3] — Not implemented; always read zero
PAEN — Pulse accumulator system enable
1 (set)
–
Pulse accumulator enabled.
0 (clear) –
Pulse accumulator disabled.
PAMOD — Pulse accumulator mode
1 (set)
–
0 (clear) –
Gated time accumulation mode.
Event counter mode.
PEDGE — Pulse accumulator edge control
8
This bit has different meanings depending on the state of the PAMOD bit, as shown:
PAMOD PEDGE
Action of clock
0
0
PAI falling edge increments the counter.
0
1
PAI rising edge increments the counter.
1
0
A zero on PAI inhibits counting.
1
1
A one on PAI inhibits counting.
I4/O5 — Input capture 4/output compare 5
1 (set)
–
0 (clear) –
Input capture 4 function is enabled (no OC5).
Output compare 5 function is enabled (no IC4)
RTR[1:0] — RTI interrupt rate selects (refer to Section 8.1.5)
TPG
MC68HC11PH8
TIMING SYSTEM
MOTOROLA
8-25
157
8.1.8.2
PACNT — Pulse accumulator count register
Pulse accumulator count (PACNT)
Address
bit 7
bit 6
bit 5
bit 4
bit 3
bit 2
bit 1
bit 0
State
on reset
$0027
(bit 7)
(6)
(5)
(4)
(3)
(2)
(1)
(bit 0)
undeÞned
This 8-bit read/write register contains the count of external input events at the PAI input, or the
accumulated count. In gated time accumulation mode, PACNT is readable even if PAI is not active.
The counter is not affected by reset and can be read or written at any time. Counting is
synchronized to the internal PH2 clock so that incrementing and reading occur during opposite
half cycles.
8.1.8.3
Pulse accumulator status and interrupt bits
The pulse accumulator control bits, PAOVI and PAII, PAOVF and PAIF are located within timer
registers TMSK2 and TFLG2.
8.1.8.4
8
TMSK2 — Timer interrupt mask 2 register
Timer interrupt mask 2 (TMSK2)
8.1.8.5
Address
bit 7
bit 6
bit 5
bit 4
bit 3
bit 2
bit 1
bit 0
State
on reset
$0024
TOI
RTII
PAOVI
PAII
0
0
PR1
PR0
0000 0000
TFLG2 — Timer interrupt flag 2 register
Timer interrupt ßag 2 (TFLG2)
Address
bit 7
bit 6
bit 5
$0025
TOF
RTIF PAOVF
bit 4
bit 3
bit 2
bit 1
bit 0
State
on reset
PAIF
0
0
0
0
0000 0000
PAOVI and PAOVF — Pulse accumulator interrupt enable and overflow flag
The PAOVF status bit is set each time the pulse accumulator count rolls over from $FF to $00. To
clear this status bit, write a one in the corresponding data bit position (bit 5) of the TFLG2 register.
The PAOVI control bit allows the pulse accumulator overflow to be configured for polled or
interrupt-driven operation and does not affect the state of PAOVF. When PAOVI is zero, pulse
accumulator overflow interrupts are inhibited, and the system operates in a polled mode, which
requires that PAOVF be polled by user software to determine when an overflow has occurred.
When the PAOVI control bit is set, a hardware interrupt request is generated each time PAOVF is
set. Before leaving the interrupt service routine, software must clear PAOVF.
TPG
MOTOROLA
8-26
TIMING SYSTEM
MC68HC11PH8
158
PAII and PAIF — Pulse accumulator input edge interrupt enable and flag
The PAIF status bit is automatically set each time a selected edge is detected at the PA7/PAI/OC1
pin. To clear this status bit, write to the TFLG2 register with a one in the corresponding data bit
position (bit 4). The PAII control bit allows the pulse accumulator input edge detect to be
configured for polled or interrupt-driven operation but does not affect setting or clearing the PAIF
bit. When PAII is zero, pulse accumulator input interrupts are inhibited, and the system operates
in a polled mode. In this mode, the PAIF bit must be polled by user software to determine when
an edge has occurred. When the PAII control bit is set, a hardware interrupt request is generated
each time PAIF is set. Before leaving the interrupt service routine, software must clear PAIF.
8.2
Pulse-width modulation (PWM) timer
The PWM timer subsystem provides up to four 8-bit pulse-width modulated waveforms on the port
H pins. Channel pairs can be concatenated to create 16-bit PWM outputs. Three clock sources
(A, B, and S) and a flexible clock select scheme give the PWM a wide range of frequencies.
Pin
PH0
PH1
PH2
PH3
Alternate
function
PW1
PW2
PW3
PW4
8
Four control registers configure the PWM outputs — PWCLK, PWPOL, PWSCAL, and PWEN.
The PWCLK register selects the prescale value for the PWM clock sources and enables the 16-bit
PWM functions. The PWPOL register determines each channel’s polarity and selects the clock
source for each channel. The PWSCAL register derives a user-scaled clock based on the A clock
source, and the PWEN register enables the PWM channels.
Each channel also has a separate 8-bit counter, period register, and duty cycle register. The period
and duty cycle registers are double buffered so that if they are changed while the channel is
enabled, the change does not take effect until the counter rolls over or the channel is disabled. A
new period or duty cycle can be forced into effect immediately by writing to the period or duty cycle
register and then writing to the counter.
With PWMs configured for 8-bit mode and E equal to 4MHz, PWM signals can be produced from
40 kHz (1% duty cycle resolution) to less than 10 cycles per second (approximately 0.4% duty
cycle resolution). By configuring the PWMs for 16-bit mode with E equal to 4MHz, PWM periods
greater than one minute are possible.
In 16-bit mode, duty cycle resolution of up to 15 parts per million can be achieved (at a PWM
frequency of 60Hz). In the same system, a PWM frequency of 1kHz corresponds to a duty cycle
resolution of 0.025%.
TPG
MC68HC11PH8
TIMING SYSTEM
MOTOROLA
8-27
159
8.2.1
PWM timer block diagram
Figure 8-5 shows the block diagram of the PWM timer subsystem. Three different clock sources
are selectable and provide inputs to the control registers. Each of the four channels has a counter,
a period register, and a duty register. The waveform output is the result of a match between the
period register (PWPERx) and the value in the counter (PWCNTx). The duty register (PWDTYx)
changes the state of the output during the period to determine the duty cycle.
8.2.2
PWCLK — PWM clock prescaler and 16-bit select register
Address
Pulse width clock select (PWCLK)
bit 7
bit 6
bit 5
bit 4
$0060 CON34 CON12 PCKA2 PCKA1
bit 3
0
bit 2
bit 1
bit 0
State
on reset
PCKB3 PCKB2 PCKB1 0000 0000
This register contains bits for selecting the 16-bit PWM options and the prescaler values for the clocks.
8.2.2.1
8
16-bit PWM function
The PWCLK register contains two control bits, each of which is used to concatenate a pair of PWM
channels into one 16-bit channel. Channels 3 and 4 are concatenated with the CON34 bit, and
channels 1 and 2 are concatenated with the CON12 bit.
When the 16-bit concatenated mode is selected, the clock source is determined by the low order
channel. Channel 2 is the low order channel when channels 1 and 2 are concatenated. Channel
4 is the low order channel when channels 3 and 4 are concatenated. The pins associated with
channels 1 and 3 can be used for general-purpose I/O when 16-bit PWM mode is selected.
Channel 1 registers are the high order byte of the double-byte channel when channels 1 and 2 are
concatenated. Channel 3 registers are the high order byte of the double-byte channel when
channels 3 and 4 are concatenated. Reads of the high order byte cause the low order byte to be
latched for one cycle to guarantee that double byte reads are accurate. Writes to the low byte of the
counter cause reset of the entire counter. Writes to the upper bytes of the counter have no effect.
CON34 — Concatenate channels 3 and 4
1 (set)
–
0 (clear) –
Channels 3 and 4 are concatenated into one 16-bit PWM channel.
Channels 3 and 4 are separate 8-bit PWMs.
When concatenated, channel 3 is the high-order byte and the channel 4 pin (PH3) is the output.
CON12 — Concatenate channels 1 and 2
1 (set)
–
0 (clear) –
Channels 1 and 2 are concatenated into one 16-bit PWM channel.
Channels 1 and 2 are separate 8-bit PWMs.
When concatenated, channel 1 is the high-order byte and the channel 2 pin (PH1) is the output.
TPG
MOTOROLA
8-28
TIMING SYSTEM
MC68HC11PH8
160
CON34
CNT4
CNT3
PWEN4
PCKB1 PCKB2 PCKB3
Clock B
Clock
select
Prescale select
÷1, 2, 4, 8, 16, 32, 64, 128
reset
PCLK4
÷2
PCLK1
CNT2
CNT1
8-bit counter
Clock S
PCLK3
EQ
8
Divider
PWEN3
Prescale select
÷1, 2, 4, 8
PCKA1
4
PCKA2
8-bit comparator
PWSCAL
MCU
E clock
PCLK2
Clock
select
Clock A
CON12
PWEN1
PWEN2
PWCNT1
PPOL1
PWCNT2
reset
reset
8-bit comparator
PWDTY1
EQ
8-bit comparator
PWPER1
EQ
8-bit comparator
PWDTY2
EQ
8-bit comparator
PWPER2
EQ
S Q
MUX
R Q
S Q
PWCNT3
PWCNT4
8-bit comparator
PWDTY3
EQ
8-bit comparator
PWPER3
EQ
8-bit comparator
PWDTY4
EQ
8-bit comparator
PWPER4
EQ
PH1/
PW2
MUX
Bit 1
PPOL2
PPOL3
Port H
pin
control
MUX
Bit 2
PH2/
PW3
MUX
Bit 3
PH3/
PW4
R Q
CON12
reset
8
16-bit
PWM
control
carry
reset
PH0/
PW1
Bit 0
S Q
R Q
16-bit
PWM
control
S Q
R Q
PPOL4
carry
CON34
Figure 8-5 PWM timer block diagram
TPG
MC68HC11PH8
TIMING SYSTEM
MOTOROLA
8-29
161
8.2.2.2
Clock prescaler selection
The three available clocks are clock A, clock B, and clock S (scaled). Clock A can be software
selected to be E, E/2, E/4, or E/8. Clock B can be software selected to be E, E/2, E/4,..., E/128.
The scaled clock (clock S) uses clock A as an input and divides it with a reloadable counter. The
rates available are software selectable to be clock A/2, down to clock A /512.
The clock source portion of the block diagram shows the three clock sources and how the scaled
clock is created. Clock A is an input to an 8-bit counter which is then compared to a user
programmable scale value. When they match, this circuit has an output that is divided by two and
the counter is reset.
Each PWM timer channel can be driven by one of two clocks. Refer to Figure 8-5.
PCKA[2:1] — Prescaler for clock A
Determines the frequency of clock A. Refer to Table 8-5.
Bit 3 — Not implemented; always reads zero
PCKB[3:1] — Prescaler for clock B
Determines the frequency of clock B. Refer to Table 8-5.
8
Table 8-5 Clock A and clock B prescalers
PCKA[2:1]
00
01
10
11
Clock A
E
E/2
E/4
E/8
PCKB[3:1]
000
001
010
011
100
101
110
111
Clock B
E
E/2
E/4
E/8
E/16
E/32
E/64
E/128
TPG
MOTOROLA
8-30
TIMING SYSTEM
MC68HC11PH8
162
8.2.3
PWPOL — PWM timer polarity & clock source select register
Address
Pulse width polarity select (PWPOL)
$0061
bit 7
bit 6
bit 5
bit 4
bit 3
bit 2
bit 1
bit 0
State
on reset
PCLK4 PCLK3 PCLK2 PCLK1 PPOL4 PPOL3 PPOL2 PPOL1 0000 0000
PCLK[4:3] — Pulse width channel 4/3 clock select
1 (set)
–
Clock S is source.
0 (clear) –
Clock B is source.
PCLK[2:1] — Pulse width channel 2/1 clock select
1 (set)
–
Clock S is source.
0 (clear) –
Clock A is source.
PPOL[4:1] — Pulse width channel x polarity
1 (set)
–
PWM channel x output is high at the beginning of the clock cycle and
goes low when duty count is reached.
0 (clear) –
PWM channel x output is low at the beginning of the clock cycle and
goes high when duty count is reached.
Each channel has a polarity bit that allows a cycle to start with either a high or a low level. This is
shown on the block diagram, Figure 8-5, as a selection of either the Q output or the Q output of the
PWM output flip flop. When one of the bits in the PWPOL register is set, the associated PWM channel
output is high at the beginning of the clock cycle, then goes low when the duty count is reached.
8.2.4
8
PWSCAL — PWM timer prescaler register
Pulse width scale (PWSCAL)
State
on reset
Address
bit 7
bit 6
bit 5
bit 4
bit 3
bit 2
bit 1
bit 0
$0062
(bit 7)
(6)
(5)
(4)
(3)
(2)
(1)
(bit 0) 0000 0000
Scaled clock S is generated by dividing clock A by the value in PWSCAL, then dividing the result
by two. If PWSCAL = $00, clock A is divided by 256, then divided by two to generate clock S.
TPG
MC68HC11PH8
TIMING SYSTEM
MOTOROLA
8-31
163
8.2.5
PWEN — PWM timer enable register
Address
Pulse width enable (PWEN)
bit 7
bit 6
$0063 TPWSL DISCP
bit 5
bit 4
0
0
bit 3
bit 2
bit 1
bit 0
State
on reset
PWEN4 PWEN3 PWEN2 PWEN1 0000 0000
Each timer has an enable bit to start its waveform output. Writing any of these PWENx bits to one
causes the associated port line to become an output regardless of the state of the associated DDR
bit. This does not change the state of the DDR bit and when PWENx returns to zero the DDR bit
again controls I/O state. On the front end of the PWM timer the clock is connected to the PWM
circuit by the PWENx enable bit being high. There is a synchronizing circuit to guarantee that the
clock will only be enabled or disabled at an edge.
PWEN contains 4 PWM enable bits — one for each channel. When an enable bit is set to one, the
pulse modulated signal becomes available at the associated port pin.
TPWSL — PWM scaled clock test bit (Test mode only)
1 (set)
–
0 (clear) –
8
Clock S output to PWSCAL register (Test only).
Normal operation.
When TPWSL is one, clock S from the PWM timer is output to PWSCAL register. Normal writing
to the PWSCAL register still functions.
DISCP — Disable compare scaled E clock (Test mode only)
1 (set)
–
0 (clear) –
Match of period does not reset associated count register (Test only).
Normal operation.
Bits [5:4] — Not implemented; always read zero
PWEN[4:1] — Pulse width channels 4–1
1 (set)
–
0 (clear) –
Channel enabled on the associated port pin.
Channel disabled.
TPG
MOTOROLA
8-32
TIMING SYSTEM
MC68HC11PH8
164
8.2.6
PWCNT1–4 — PWM timer counter registers 1 to 4
State
on reset
Address
bit 7
bit 6
bit 5
bit 4
bit 3
bit 2
bit 1
bit 0
Pulse width count 1 (PWCNT1)
$0064
(bit 7)
(6)
(5)
(4)
(3)
(2)
(1)
(bit 0) 0000 0000
Pulse width count 2 (PWCNT2)
$0065
(bit 7)
(6)
(5)
(4)
(3)
(2)
(1)
(bit 0) 0000 0000
Pulse width count 3 (PWCNT3)
$0066
(bit 7)
(6)
(5)
(4)
(3)
(2)
(1)
(bit 0) 0000 0000
Pulse width count 4 (PWCNT4)
$0067
(bit 7)
(6)
(5)
(4)
(3)
(2)
(1)
(bit 0) 0000 0000
Each channel has its own counter which can be read at any time without affecting the count or the
operation of the PWM channel. Writing to a counter causes it to be reset to $00; this is generally
done before the counter is enabled. A counter may also be written to whilst it is enabled; this may
cause a truncated PWM period.
8.2.7
PWPER1–4 — PWM timer period registers 1 to 4
State
on reset
Address
bit 7
bit 6
bit 5
bit 4
bit 3
bit 2
bit 1
bit 0
Pulse width period 1 (PWPER1)
$0068
(bit 7)
(6)
(5)
(4)
(3)
(2)
(1)
(bit 0) 1111 1111
Pulse width period 2 (PWPER2)
$0069
(bit 7)
(6)
(5)
(4)
(3)
(2)
(1)
(bit 0) 1111 1111
Pulse width period 3 (PWPER3)
$006A
(bit 7)
(6)
(5)
(4)
(3)
(2)
(1)
(bit 0) 1111 1111
Pulse width period 4 (PWPER4)
$006B
(bit 7)
(6)
(5)
(4)
(3)
(2)
(1)
(bit 0) 1111 1111
8
There is one period register for each channel. The value in this register determines the period of
the associated PWM timer channel. PWPERx is connected internally to a buffer which compares
directly with the counter register. The period value in PWPERx is loaded into the buffer when the
counter is cleared by the termination of the previous period or by a write to the counter. This
register can be written at any time, and the written value will take effect from the start of the next
PWM timer cycle. Reads of this register return the most recent value written.
TPG
MC68HC11PH8
TIMING SYSTEM
MOTOROLA
8-33
165
8.2.8
PWDTY1–4 — PWM timer duty cycle registers 1 to 4
State
on reset
Address
bit 7
bit 6
bit 5
bit 4
bit 3
bit 2
bit 1
bit 0
Pulse width duty 1 (PWDTY1)
$006C
(bit 7)
(6)
(5)
(4)
(3)
(2)
(1)
(bit 0) 1111 1111
Pulse width duty 2 (PWDTY2)
$006D
(bit 7)
(6)
(5)
(4)
(3)
(2)
(1)
(bit 0) 1111 1111
Pulse width duty 3 (PWDTY3)
$006E
(bit 7)
(6)
(5)
(4)
(3)
(2)
(1)
(bit 0) 1111 1111
Pulse width duty 4 (PWDTY4)
$006F
(bit 7)
(6)
(5)
(4)
(3)
(2)
(1)
(bit 0) 1111 1111
There is one duty register for each channel. The value in this register determines the duty cycle of
the associated PWM timer channel. PWDTYx is compared to the counter contents and if they are
equal, a match occurs and the output goes to the state defined by the associated polarity bit. If the
register is written while the channel is enabled, then the new value is held in a buffer until the counter
rolls over or the channel is disabled. Reads of this register return the most recent value written.
Note:
If PWDTYx ≥ PWPERx then there will be no change of state due to the duty cycle value.
In addition, if the duty register is set to $00, then the output will always be in the state
which would normally be result from the duty change of state (see also Section 8.2.9).
PWMx
8
PWDTYx
PWPERx
Figure 8-6 PWM duty cycle
8.2.9
Boundary cases
The following boundary conditions apply to the values stored in the PWDTYx and PWPERx
registers and the PPOLx bits:
•
If PWDTYx = $00, PWPERx > $00 and PPOLx = 0 then the output is always high.
•
If PWDTYx = $00, PWPERx > $00 and PPOLx = 1 then the output is always low.
•
If PWDTYx ≥ PWPERx and PPOLx = 0 then the output is always low.
•
If PWDTYx ≥ PWPERx and PPOLx = 1 then the output is always high.
•
If PWPERx = $00 and PPOLx = 0 then the output is always low.
•
If PWPERx = $00 and PPOLx = 1 then the output is always high.
TPG
MOTOROLA
8-34
TIMING SYSTEM
MC68HC11PH8
166
8.3
8-bit modulus timers
The MC68HC11PH8 has three 8-bit modulus timers: A, B and C. These timers can generate a
wide range of low-frequency, periodic interrupts. In addition, timer A may be used as a clock
source for the LCD segments, the COP watchdog system and the real time interrupt (RTI), in
applications using PLL clock generation.
Each modulus timer consists of an 8-bit down-counter, an 8-bit modulus register and a load
mechanism. Only the 8-bit modulus register may be written to in software. Each timer is configured
by an associated control register that enables and flags interrupts, and selects the clock source
for the down-counter. Figure 8-7 provides a block diagram of the modulus timers.
8.3.1
Modulus timer operation
The down-counter in each timer contains a value which is decremented at a preselected clock
rate. When this counter value reaches $00 (‘underflow’), an output pulse is generated and, if
enabled, a hardware interrupt is requested. At this point, a new value is loaded into the
down-counter from the modulus register; at the next clock, the counter will contain this value minus
one.
Note:
For all three timers, modulus register values of $00 or $01 should be avoided.
Because modulus timer A is used to clock the COP monitor and cannot be stopped, the
loading mechanism on modulus timer A is inhibited for values of $00 or $01; at
underflow, the counter will roll over from $00 to $FF and continue decrementing.
8
The frequency that is output from the timer is equal to the clock frequency divided by the value in
the 8-bit modulus register; a modulus register value of n generates a modulus timer underflow
every n input clocks. Therefore, the modulus timer can divide an input frequency by any value from
2 to 255. In addition, the timer A clock output is further divided by two to give the CLK64 signal.
There are several software-selectable input clocks for the modulus timers (see Section 8.3.2 and
Figure 8-7). For example, the modulus timer A clock source can be EXTALi, EXTALi/4 or EXTALi/8.
Consequently, CLK64 can vary in frequency from EXTALi/4 (EXTALi ÷ 2 ÷ 2) to EXTALi/4080
(EXTALi/8 ÷ 255 ÷ 2). The following table provides an example of how to obtain a 64Hz frequency
from various EXTALi values, using timer A.
EXTALi
32kHz
32.768kHz
38.4kHz
Input clock
EXTALi
EXTALi/4
EXTALi/4
Modulus timer A
Modulus register
$FA
$40
$46
Output
64Hz
64Hz
64Hz
TPG
MC68HC11PH8
TIMING SYSTEM
MOTOROLA
8-35
167
T8AI
&
T8AF
T8ACR
0
Data bus
Data bus
0
Load
0
CSA0
Underßow
detect
8-bit down-counter
Timer
A
Clock
CSA1
CSA2
T8ADR
Clock
select
Data bus
EXTALi
EXTALi/4
EXTALi/8
Modulus
timer
interrupt
request
÷2
CLK64
T8BI
+
&
T8BF
Data bus
T8BCR
0
Data bus
0
Load
+
PRB
CSB0
8
Underßow
detect
8-bit down-counter
Timer
B
Clock
CSB1
CSB2
PH7
T8BDR
Clock
select
Data bus
Stop
EXTALi
EXTALi/4
EXTALi/8
Timer A output clock
Timer C output clock
T8CI
&
T8CF
Data bus
T8CCR
0
Data bus
0
PRC
+
CSC0
Load
8-bit down-counter
Underßow
detect
Clock
Timer
C
CSC1
CSC2
PH6
Stop
EXTALi
EXTALi/4
EXTALi/8
Clock
select
T8CDR
Data bus
Timer B output clock
Timer A output clock
Figure 8-7 8-bit modulus timer system
TPG
MOTOROLA
8-36
TIMING SYSTEM
MC68HC11PH8
168
The modulus register can be written to at any time without affecting the down-counter; care must
be taken by the programmer to ensure that a new value is written to the modulus register before
the down-counter reaches $00, unless the previous value is to be reloaded. A read of the modulus
register with the timer running will access a latched value of the down-counter. This latch
guarantees a stable value during the read and is updated with each timer clock. To determine the
value in the modulus register itself (for timers B and C), the timer must be stopped by the
appropriate clock selection (see Section 8.3.2), then a one must be written to the preset bit in the
control register. The down-counter now contains the modulus register value.
Note:
Because it is used to clock the COP watchdog in applications using PLL clock
generation, timer A cannot be stopped (therefore, the value in modulus register A
cannot be determined).
Note:
The timer preset bits only have an effect if the timer is stopped under hardware control
(timers B and C only).
The recommended procedure for configuring timers B and C is as follows:
1) Stop the timer by writing %000 to the relevant clock select control bits.
2) Set the modulus register by writing the required value to the timer data register.
3) Write a one to the timer preset bit.
4) Select the desired clock source to start the counter decrementing.
8.3.2
8
Clock rate selection
A number of clock rates can be selected in software for each of the three modulus timers. The
selection is controlled by bits 0-2 in the timer control register, as shown in the tables below.
Timer A may be used as a prescaler for timers B and C (see Figure 8-7). Similarly timer B may be
used as a prescaler for timer C, and vice versa.
Table 8-6 Modulus timers clock sources
CSA[2:0]
000
001
010
011
100
101
110
111
Timer A clock source
EXTALi/8
EXTALi
EXTALi/4
EXTALi/8
EXTALi/8
EXTALi/8
EXTALi/8
EXTALi/8
CSB[2:0] Timer B clock source
000
Stopped
001
EXTALi
010
EXTALi/4
011
EXTALi/8
100
Timer A underßow
101
Timer C underßow
110
Rising edge PH7
111
Stopped
CSC[2:0] Timer C clock source
000
Stopped
001
EXTALi
010
EXTALi /4
011
EXTALi /8
100
Timer A underßow
101
Timer B underßow
110
Rising edge PH6
111
Stopped
Warning: Selecting EXTALi as a clock source when the PLL function is not used, i.e. when the
bus frequency is EXTALi/4, could lead to read or write errors in the timer registers.
TPG
MC68HC11PH8
TIMING SYSTEM
MOTOROLA
8-37
169
8.3.2.1
T8ADR — 8-bit modulus timer A data register
8-bit modulus timer A data (T8ADR)
Address
bit 7
bit 6
bit 5
bit 4
bit 3
bit 2
bit 1
bit 0
State
on reset
$0059
(bit 7)
(6)
(5)
(4)
(3)
(2)
(1)
(0)
1111 1111
This 8-bit register contains the value that will be loaded into the timer A down-counter on the next
underflow. At reset, the timer A clock source is the EXTALi clock divided by 8, and the modulus
register is initialized to its highest value.
Because timer A is used to clock the COP watchdog in applications using the PLL clock
generation, it is not possible to stop timer A. For the same reason, a write of values $00 or $01 to
this register will not be loaded from the modulus register to the counter.
8.3.2.2
T8ACR — 8-bit modulus timer A control register
State
on reset
Address
bit 7
bit 6
bit 5
bit 4
bit 3
bit 2
bit 1
bit 0
8-bit modulus timer A control (T8ACR) $005D
T8AI
T8AF
0
0
0
CSA2
CSA1
CSA0 0000 0000
T8AI — 8-bit timer A interrupt enable
8
1 (set)
–
0 (clear) –
Hardware interrupt requested when T8AF flag set.
Interrupt disabled.
When set, an 8-bit modulus timer interrupt occurs when the timer reaches $00. At this time the
timer counter is loaded with the value stored in T8ADR and the 8-bit counter will continue to count
down at the selected clock rate.
T8AF — 8-bit timer A underflow flag
Set when 8-bit modulus timer A reaches $00. An interrupt is generated if enabled by T8AI. This bit
is cleared by a write to the T8ACR register with T8AF set.
Bits [5:3] — Not implemented; always read zero
CSA[2:0] — 8-bit timer A clock rate
These bits select the timer A clock, as shown in Table 8-6.
TPG
MOTOROLA
8-38
TIMING SYSTEM
MC68HC11PH8
170
8.3.2.3
T8BDR — 8-bit modulus timer B data register
8-bit modulus timer B data (T8BDR)
Address
bit 7
bit 6
bit 5
bit 4
bit 3
bit 2
bit 1
bit 0
State
on reset
$005A
(bit 7)
(6)
(5)
(4)
(3)
(2)
(1)
(0)
undeÞned
This 8-bit register contains the value that will be loaded into the timer B down-counter at the next
underflow. At reset, timer B is stopped and the state of the modulus register is indeterminate.
8.3.2.4
T8BCR — 8-bit modulus timer B control register
Address
8-bit modulus timer B control (T8BCR) $005E
State
on reset
bit 7
bit 6
bit 5
bit 4
bit 3
bit 2
bit 1
bit 0
T8BI
T8BF
0
0
PRB
CSB2
CSB1
CSB0 0000 0000
T8BI — 8-bit timer B interrupt enable
1 (set)
–
0 (clear) –
Hardware interrupt requested when T8BF flag set.
Interrupt disabled.
When set, an 8-bit modulus timer interrupt occurs when the timer reaches $00. At this time the
timer counter is loaded with the value stored in T8BDR and the 8-bit counter will continue to count
down at the selected clock rate.
8
T8BF — 8-bit timer B underflow flag
1 (set)
–
0 (clear) –
Underflow has occurred.
No underflow has occurred.
Set when 8-bit modulus timer B reaches $00. An interrupt is generated if enabled by T8BI. This bit
is cleared by a write to the T8BCR register with T8BF set.
Bits [5, 4] — Not implemented; always read zero
PRB — 8-bit timer B preset
A write to the T8BCR register with this bit set will preset the timer B counter to the modulus register
value. The clock must be stopped before writing to the register. This bit always reads as 0.
CSB[2:0] — 8-bit timer B clock rate
These bits select the timer B clock, as shown in Table 8-6. At reset, timer B is not clocked.
TPG
MC68HC11PH8
TIMING SYSTEM
MOTOROLA
8-39
171
8.3.2.5
T8CDR — 8-bit modulus timer C data register
8-bit modulus timer C data (T8CDR)
Address
bit 7
bit 6
bit 5
bit 4
bit 3
bit 2
bit 1
bit 0
State
on reset
$005B
(bit 7)
(6)
(5)
(4)
(3)
(2)
(1)
(0)
undeÞned
This 8-bit register contains the value that will be loaded into the timer C down-counter at the next
underflow. At reset, timer C is stopped and state of the modulus register is indeterminate.
8.3.2.6
T8CCR — 8-bit modulus timer C control register
Address
8-bit modulus timer C control (T8CCR) $005F
bit 7
bit 6
bit 5
bit 4
bit 3
bit 2
bit 1
T8CI
T8CF
0
0
PRC
CSC2
CSC1
bit 0
State
on reset
CSC0 0000 0000
T8CI8 — bit timer C interrupt enable
1 (set)
–
0 (clear) –
8
Hardware interrupt requested when T8CF flag set.
Interrupt disabled.
When set, an 8-bit modulus timer interrupt occurs when the timer reaches $00. At this time the
timer counter is loaded with the value stored in T8CDR and the 8-bit counter will continue to count
down at the selected clock rate.
T8CF — 8-bit timer C underflow flag
1 (set)
–
0 (clear) –
Underflow has occurred.
No underflow has occurred.
Set when 8-bit modulus timer C reaches $00. An interrupt is generated if enabled by T8CI. This
bit is cleared by a write to the T8CCR register with T8CF set.
Bits [5, 4] — Not implemented; always read zero
PRC — 8-bit timer C preset
A write to the T8CCR register with this bit set will preset the timer C counter to the modulus register
value. The clock must be stopped before writing to the register. This bit always reads as 0.
CSC[2:0] — 8-bit timer C clock rate
These bits select the timer C clock, as shown in Table 8-6. At reset, timer C is not clocked.
TPG
MOTOROLA
8-40
TIMING SYSTEM
MC68HC11PH8
172
9
ANALOG-TO-DIGITAL CONVERTER
The analog-to-digital (A/D) system, a successive approximation converter, uses an all-capacitive
charge redistribution technique to convert analog signals to digital values.
The A/D converter shares input pins with port E:
Pin
PE0
PE1
PE2
PE3
PE4
PE5
PE6
PE7
9.1
Alternate
function
AD0
AD1
AD2
AD3
AD4
AD5
AD6
AD7
9
Overview
The A/D system is an 8-channel, 8-bit, multiplexed-input converter. The VDD AD and VSS AD
pins are used to input supply voltage to the A/D converter. This allows the supply voltage to be
bypassed independently. The converter does not require external sample and hold circuits
because of the type of charge redistribution technique used. A/D converter timing can be
synchronized to the system E clock, or to an internal resistor capacitor (RC) oscillator. The A/D
converter system consists of four functional blocks: multiplexer, analog converter, digital control
and result storage. Refer to Figure 9-1.
TPG
MC68HC11PH8
ANALOG-TO-DIGITAL CONVERTER
MOTOROLA
9-1
173
PE0/
AD0
VRH
VRL
8-bit capacitive DAC
with sample and hold
PE1/
AD1
Successive approximation
register and control
PE2/
AD2
PE3/
AD3
PE4/
AD4
Result
Internal
data bus
Analog
MUX
0
SCAN
MULT
PE6/
AD6
CD
CC
CB
PE7/
AD7
CA
ADCTL Ð A/D control
CCF
PE5/
AD5
Result register interface
ADR1 - A/D result 1
ADR2 - A/D result 2
ADR3 - A/D result 3
ADR4 - A/D result 4
9
Figure 9-1 A/D converter block diagram
9.1.1
Multiplexer
The multiplexer selects one of 16 inputs for conversion. Input selection is controlled by the value
of bits CD – CA in the ADCTL register. The eight port E pins are fixed-direction analog inputs to
the multiplexer, and additional internal analog signal lines are routed to it.
Port E pins can also be used as digital inputs (see Section 4). Digital reads of port E pins should
be avoided during the sample portion of an A/D conversion cycle, when the gate signal to the
N-channel input gate is on. Because no P-channel devices are directly connected to either input
pins or reference voltage pins, voltages above VDD do not cause a latchup problem, although
current and voltage should be limited according to maximum ratings. Refer to Figure 9-2, which is
a functional diagram of an input pin.
TPG
MOTOROLA
9-2
ANALOG-TO-DIGITAL CONVERTER
MC68HC11PH8
174
Input
protection
device
Analog
input
Diffusion and
poly coupler
≤4kΩ
Note 1
<2pF
20pF
+20V
Ð0.7V
400nA
junction
leakage
DAC
capacitance
VRL
Note 1: The analog switch is closed only during the 12 cycle sample time
Note 2: All component values are approximate
Figure 9-2 Electrical model of an A/D input pin (in sample mode)
9.1.2
Analog converter
Conversion of an analog input selected by the multiplexer occurs in this block. It contains a
digital-to-analog capacitor (DAC) array, a comparator, and a successive approximation register
(SAR). Each conversion is a sequence of eight comparison operations, beginning with the most
significant bit (MSB). Each comparison determines the value of a bit in the SAR.
The DAC array performs two functions. It acts as a sample and hold circuit during the entire
conversion sequence, and provides comparison voltage to the comparator during each
successive comparison.
The result of each successive comparison is stored in the SAR. When a conversion sequence is
complete, the contents of the SAR are transferred to the appropriate result register.
9
A charge pump provides switching voltage to the gates of analog switches in the multiplexer.
Charge pump output must stabilize between 7 and 8 volts within up to 100 µs before the converter
can be used. The charge pump is enabled by the ADPU bit in the OPTION register.
9.1.3
Digital control
All A/D converter operations are controlled by bits in register ADCTL. In addition to selecting the
analog input to be converted, ADCTL bits indicate conversion status, and control whether single
or continuous conversions are performed. Finally, the ADCTL bits determine whether conversions
are performed on single or multiple channels.
TPG
MC68HC11PH8
ANALOG-TO-DIGITAL CONVERTER
MOTOROLA
9-3
175
9.1.4
Result registers
Four 8-bit registers (ADR1 – ADR4) store conversion results. Each of these registers can be
accessed by the processor in the CPU. The conversion complete flag (CCF) indicates when valid
data is present in the result registers. The result registers are written during a portion of the system
clock cycle when reads do not occur, so there is no conflict.
9.1.5
A/D converter clocks
The CSEL bit in the OPTION register selects whether the A/D converter uses the system E clock
or an internal RC oscillator for synchronization. When E clock frequency is below 750kHz, charge
leakage in the capacitor array can cause errors, and the internal oscillator should be used. When
the RC clock is used, additional errors can occur because the comparator is sensitive to the
additional system clock noise.
9.1.6
Conversion sequence
A/D converter operations are performed in sequences of four conversions each. A conversion
sequence can repeat continuously or stop after one iteration. The conversion complete flag (CCF)
is set after the fourth conversion in a sequence to show the availability of data in the result
registers. Figure 9-3 shows the timing of a typical sequence. Synchronization is referenced to the
system E clock.
12 cycles
4 cycles
MSB
2 cyc 2 cyc 2 cyc 2 cyc 2 cyc 2 cyc 2 cyc 2 cyc
bit 6 bit 5 bit 4 bit 3 bit 2 bit 1 bit 0
END
Successive approximation sequence
Set CCF ßag
Sample analog input
Convert Þrst
channel and
update ADR1
0
Convert second
channel and
update ADR2
32
Convert third
channel and
update ADR3
64
Repeat sequence if SCAN = 1
E clock
Write to ADCTL
9
Convert fourth
channel and
update ADR4
96
128 E clock cycles
Figure 9-3 A/D conversion sequence
TPG
MOTOROLA
9-4
ANALOG-TO-DIGITAL CONVERTER
MC68HC11PH8
176
9.1.7
Conversion process
The A/D conversion sequence begins one E clock cycle after a write to the A/D control/status
register, ADCTL. The bits in ADCTL select the channel and the mode of conversion.
An input voltage equal to VRL converts to $00 and an input voltage equal to VRH converts to $FF
(full scale), with no overflow indication. For ratiometric conversions of this type, the source of each
analog input should use VRH as the supply voltage and be referenced to VRL.
9.2
A/D converter power-up and clock select
ADPU (bit 7 of the OPTION register) controls A/D converter power up. Clearing ADPU removes
power from and disables the A/D converter system; setting ADPU enables the A/D converter
system. After the A/D converter is turned on, the analog bias voltages will take up to 100µs to
stabilize.
When the A/D converter system is operating from the MCU E clock, all switching and comparator
operations are synchronized to the MCU clocks. This allows the comparator results to be sampled
at ‘quiet’ times, which minimizes noise errors. The internal RC oscillator is asynchronous with
respect to the MCU clock, so noise can affect the A/D converter results. This results in a slightly
lower typical accuracy when using the internal oscillator (CSEL = 1).
9.2.1
OPTION — System configuration options register 1
Address
System conÞg. options 1 (OPTION)
$0039
bit 6
bit 5
bit 4
bit 3
bit 2
bit 1
bit 0
State
on reset
ADPU CSEL
IRQE
DLY
CME
FCME
CR1
CR0
0001 0000
bit 7
9
The 8-bit special-purpose OPTION register sets internal system configuration options during
initialization. The time protected control bits, IRQE, DLY, FCME and CR[1:0] can be written to only
once in the first 64 cycles after a reset and then they become read-only bits. This minimizes the
possibility of any accidental changes to the system configuration. They may be written at any time
in special modes.
ADPU — A/D power-up
1 (set)
–
0 (clear) –
A/D system power enabled.
A/D system disabled, to reduce supply current.
After enabling the A/D power, at least 100µs should be allowed for system stabilization.
TPG
MC68HC11PH8
ANALOG-TO-DIGITAL CONVERTER
MOTOROLA
9-5
177
CSEL — Clock select
1 (set)
–
0 (clear) –
A/D, EPROM and EEPROM use internal RC clock source
(about 1.5MHz).
A/D, EPROM and EEPROM use system E clock
(must be at least 1MHz).
Selects alternate clock source for on-chip EPROM, EEPROM and A/D charge pumps. The on-chip
RC clock should be used when the E clock frequency falls below 1MHz.
IRQE — Configure IRQ for falling edge sensitive operation (refer to Section 3)
1 (set)
–
0 (clear) –
Falling edge sensitive operation.
Low level sensitive operation.
DLY — Enable oscillator start-up delay (refer to Section 3)
1 (set)
–
A stabilization delay is imposed as the MCU is started up from STOP
mode or from power-on reset.
0 (clear) –
The oscillator start-up delay coming out of STOP is bypassed and the
MCU resumes processing within about four bus cycles. A stable
external oscillator is required if this option is selected.
CME — Clock monitor enable (refer to Section 10)
1 (set)
9
–
Clock monitor enabled.
0 (clear) –
Clock monitor disabled.
FCME — Force clock monitor enable (refer to Section 10)
1 (set)
–
0 (clear) –
Clock monitor enabled, cannot be disabled until next reset.
Clock monitor follows the state of the CME bit.
CR[1:0] — COP timer rate select bits (refer to Section 10)
TPG
MOTOROLA
9-6
ANALOG-TO-DIGITAL CONVERTER
MC68HC11PH8
178
9.3
Channel assignments
The multiplexer allows the A/D converter to select one of sixteen analog signals. Eight of these
channels correspond to port E input lines to the MCU, four others are internal reference points or
test functions; the remaining four channels are reserved. Refer to Table 9-1.
Table 9-1 A/D converter channel assignments
Channel Channel Result in ADRx
number
signal
if MULT = 1
1
AD0
ADR1
2
AD1
ADR2
3
AD2
ADR3
4
AD3
ADR4
5
AD4
ADR1
6
AD5
ADR2
7
AD6
ADR3
8
AD7
ADR4
9Ð12
reserved
Ñ
ADR1
13
VRH(1)
14
VRL(1)
ADR2
15
VRH/2(1)
ADR3
16
reserved(1)
ADR4
(1) Used for factory testing.
9
9.3.1
Single-channel operation
There are two types of single-channel operation. In the first type (SCAN = 0), the single selected
channel is converted four consecutive times. The first result is stored in A/D result register 1
(ADR1), and the fourth result is stored in ADR4. After the fourth conversion is complete, all
conversion activity is halted until a new conversion command is written to the ADCTL register. In
the second type of single-channel operation (SCAN = 1), conversions continue to be performed
on the selected channel with the fifth conversion being stored in register ADR1 (overwriting the
first conversion result), the sixth conversion overwriting ADR2, and so on.
TPG
MC68HC11PH8
ANALOG-TO-DIGITAL CONVERTER
MOTOROLA
9-7
179
9.3.2
Multiple-channel operation
There are two types of multiple-channel operation. In the first type (SCAN = 0), a selected group
of four channels is converted once only. The first result is stored in A/D result register 1 (ADR1),
and the fourth result is stored in ADR4. After the fourth conversion is complete, all conversion
activity is halted until a new conversion command is written to the ADCTL register. In the second
type of multiple-channel operation (SCAN = 1), conversions continue to be performed on the
selected group of channels with the fifth conversion being stored in register ADR1 (replacing the
earlier conversion result for the first channel in the group), the sixth conversion overwriting ADR2,
and so on.
9.4
Control, status and results registers
9.4.1
ADCTL — A/D control and status register
A/D control & status (ADCTL)
9
Address
bit 7
bit 6
$0030
CCF
0
bit 4
bit 3
bit 2
bit 1
bit 0
State
on reset
SCAN MULT
CD
CC
CB
CA
u0uu uuuu
bit 5
All bits in this register can be read or written, except bit 7, which is a read-only status indicator,
and bit 6, which always reads as zero. Write to ADCTL to initiate a conversion. To quit a conversion
in progress, write to this register and a new conversion sequence begins immediately.
CCF — Conversions complete flag
1 (set)
–
0 (clear) –
All four A/D result registers contain valid conversion data.
At least one of the A/D result registers contains invalid data.
A read-only status indicator, this bit is set when all four A/D result registers contain valid
conversion results. Each time the ADCTL register is overwritten, this bit is automatically cleared
to zero and a conversion sequence is started. In the continuous mode, CCF is set at the end of
the first conversion sequence.
Bit 6 — Not implemented; always reads zero.
SCAN — Continuous scan control
1 (set)
–
0 (clear) –
A/D conversions take place continuously.
Each of the four conversions is performed only once.
When this control bit is clear, the four requested conversions are performed once to fill the four
result registers. When this control bit is set, the four conversions are repeated continuously with
the result registers updated as data becomes available.
TPG
MOTOROLA
9-8
ANALOG-TO-DIGITAL CONVERTER
MC68HC11PH8
180
MULT — Multiple-channel/single-channel control
1 (set)
–
0 (clear) –
Each A/D channel has a result register allocated to it.
Four consecutive conversions from the same A/D channel are stored
in the results registers.
When this bit is clear, the A/D converter system is configured to perform four consecutive
conversions on the single channel specified by the four channel select bits CD–CA (bits 3–0 of the
ADCTL register). When this bit is set, the A/D system is configured to perform a conversion on
each of the four channels where each result register corresponds to one channel.
Note:
When the multiple-channel continuous scan mode is used, extra care is needed in the
design of circuitry driving the A/D inputs. The charge on the capacitive DAC array before
the sample time is related to the voltage on the previously converted channel. A charge
share situation exists between the internal DAC capacitance and the external circuit
capacitance. Although the amount of charge involved is small, the rate at which it is
repeated is every 64 µs for an E clock of 2 MHz. The RC charging rate of the external circuit
must be balanced against this charge sharing effect to avoid errors in accuracy. Refer to the
M68HC11 Reference Manual (M68HC11RM/AD) for further information.
CD–CA — Channel selects D–A
When a multiple channel mode is selected (MULT = 1), the two least significant channel select bits
(CB and CA) have no meaning and the CD and CC bits specify which group of four channels is to
be converted.
9
Channel select
control bits Channel Result in ADRx
signal
if MULT = 1
CD:CC:CB:CA
0000
AD0
ADR1
0001
AD1
ADR2
0010
AD2
ADR3
0011
AD3
ADR4
0100
AD4
ADR1
0101
AD5
ADR2
0110
AD6
ADR3
0111
AD7
ADR4
10XX
reserved
Ñ
1100
VRH(1)
ADR1
1101
VRL(1)
ADR2
1110
VRH/2(1)
ADR3
reserved(1
1111
ADR4
)
TPG
MC68HC11PH8
ANALOG-TO-DIGITAL CONVERTER
MOTOROLA
9-9
181
(1) Used for factory testing.
9.4.2
ADR1–ADR4 — A/D converter results registers
Address
bit 7
bit 6
bit 5
bit 4
bit 3
bit 2
bit 1
bit 0
State
on reset
A/D result 1 (ADR1)
$0031
(bit 7)
(6)
(5)
(4)
(3)
(2)
(1)
(bit 0)
undeÞned
A/D result 2 (ADR2)
$0032
(bit 7)
(6)
(5)
(4)
(3)
(2)
(1)
(bit 0)
undeÞned
A/D result 3 (ADR3)
$0033
(bit 7)
(6)
(5)
(4)
(3)
(2)
(1)
(bit 0)
undeÞned
A/D result 4 (ADR4)
$0034
(bit 7)
(6)
(5)
(4)
(3)
(2)
(1)
(bit 0)
undeÞned
These read-only registers hold an 8-bit conversion result. Writes to these registers have no effect.
Data in the A/D converter result registers is valid when the CCF flag in the ADCTL register is set,
indicating a conversion sequence is complete. If conversion results are needed sooner, refer to
Figure 9-3, which shows the A/D conversion sequence diagram.
9.5
9
Operation in STOP and WAIT modes
If a conversion sequence is in progress when either the STOP or WAIT mode is entered, the
conversion of the current channel is suspended. When the MCU resumes normal operation, that
channel is resampled and the conversion sequence is resumed. As the MCU exits the WAIT mode,
the A/D circuits are stable and valid results can be obtained on the first conversion. However, in
STOP mode, all analog bias currents are disabled and it is necessary to allow a stabilization period
when leaving the STOP mode. If the STOP mode is exited with a delay (DLY = 1), there is enough
time for these circuits to stabilize before the first conversion. If the STOP mode is exited with no
delay (DLY bit in OPTION register = 0), allow 10 ms for the A/D circuitry to stabilize to avoid invalid
results.
TPG
MOTOROLA
9-10
ANALOG-TO-DIGITAL CONVERTER
MC68HC11PH8
182
10
RESETS AND INTERRUPTS
Resets and interrupt operations load the program counter with a vector that points to a new
location from which instructions are to be fetched. A reset immediately stops execution of the
current instruction and forces the program counter to a known starting address. Internal registers
and control bits are initialized so that the MCU can resume executing instructions. An interrupt
temporarily suspends normal program execution whilst an interrupt service routine is being
executed. After an interrupt has been serviced, the main program resumes as if there had been
no interruption.
10.1
Resets
There are four possible sources of reset. Power-on reset (POR) and external reset share the
normal reset vector. The computer operating properly (COP) reset and the clock monitor reset
each has its own vector.
10.1.1
Power-on reset
A positive transition on VDD generates a power-on reset (POR), which is used only for power-up
conditions. POR cannot be used to detect drops in power supply voltages. A delay is imposed
which allows the clock generator to stabilize after the oscillator becomes active. If RESET is at
logical zero at the end of the delay time, the CPU remains in the reset condition until RESET goes
to logical one. A mask option selects one of two delay times; either 128 or 4064 tCYC (internal clock
cycles).
Note:
10
This mask option is not available on the MC68HC711PH8, where the delay time is
4064 tCYC.
It is important to protect the MCU during power transitions. Most M68HC11 systems need an
external circuit that holds the RESET pin low whenever VDD is below the minimum operating level.
This external voltage level detector, or other external reset circuits, are the usual source of reset
in a system. The POR circuit only initializes internal circuitry during cold starts. Refer to Figure 2-3.
TPG
MC68HC11PH8
RESETS AND INTERRUPTS
MOTOROLA
10-1
183
10.1.2
External reset (RESET)
The CPU distinguishes between internal and external reset conditions by sensing whether the
reset pin rises to a logic one in less than four E clock cycles after an internal device releases reset.
When a reset condition is sensed, the RESET pin is driven low by an internal device for eight E
clock cycles, then released. Four E clock cycles later it is sampled. If the pin is still held low, the
CPU assumes that an external reset has occurred. If the pin is high, it indicates that the reset was
initiated internally by either the COP system or the clock monitor. It is not advisable to connect an
external resistor capacitor (RC) power-up delay circuit to the reset pin of M68HC11 devices
because the circuit charge time constant can cause the device to misinterpret the type of reset
that occurred. To guarantee recognition of an external reset, the RESET pin should be held low
for at least 16 clock cycles.
10.1.3
COP reset
The MCU includes a COP system to help protect against software failures. When the COP is
enabled, the software is responsible for keeping a free-running watchdog timer from timing out.
When the software is no longer being executed in the intended sequence, a system reset is
initiated.
The state of the NOCOP bit in the CONFIG register determines whether the COP system is
enabled or disabled. To change the enable status of the COP system, change the contents of the
CONFIG register and then perform a system reset. In the special test and bootstrap operating
modes, the COP system is initially inhibited by the disable resets (DISR) control bit in the TEST1
register. The DISR bit can subsequently be written to zero to enable COP resets.
10
The COP function has two possible clock sources. When PLL clock generation is not used
(VDDSYN = 0), the clocking chain for the COP function is tapped off from the main timer divider
chain (E/215); refer to Figure 8-1. When the PLL clock generation is used (VDDSYN = 1), the COP
function can be clocked by the underflow of the 8-bit modulus timer A (CLK64/4); see Figure 8-2.
The COP timer rate control bits CR[1:0] in the OPTION register determine the COP timeout
period. The COP clock source frequency is scaled by the factor shown in Table 10-1 or Table 10-2.
After reset, bits CR[1:0] are zero, which selects the shortest timeout period. In normal operating
modes, these bits can only be written once, within 64 bus cycles after reset.
TPG
MOTOROLA
10-2
RESETS AND INTERRUPTS
MC68HC11PH8
184
Table 10-1 COP timer rate select (PLL disabled)
CR[1:0]
00
01
10
11
Divide EXTALi = 8MHz: EXTALi = 12MHz: EXTALi = 16MHz:
E/215 by
timeout(1)
timeout(1)
timeout(1)
1
16.384 ms
10.923 ms
8.192 ms
4
65.536 ms
43.691 ms
32.768 ms
16
262.14 ms
174.76 ms
131.07 ms
64
1.049 sec
699.05 ms
524.29 ms
E=
2.0 MHz
3.0 MHz
4.0 MHz
(1) The timeout period has a tolerance of Ð0/+one cycle of the E/215 clock due to
the asynchronous implementation of the COP circuitry. For example, with
EXTALi = 8MHz, the uncertainty is Ð0/+16.384ms. See also the M68HC11
Reference Manual, (M68HC11RM/AD).
Table 10-2 COP timer rate select (PLL enabled)
CR[1:0]
00
01
10
11
Divide
CLK64 = 4.096 kHz:
CLK64 by
timeout(1)
4
1 ms
16
3.9 ms
64
15.6 ms
256
62.5 sec
CLK64 =64 Hz:
timeout(1)
62.5 ms
250 ms
1s
4s
CLK64 = 4 Hz:
timeout(1)
1s
4s
16 s
64 s
(1) The timeout period has a tolerance of Ð0/+one cycle of the CLK64/4 clock due to
the asynchronous implementation of the COP circuitry. For example, with
CLK64 = 64 Hz, the uncertainty is Ð0/+62.5ms. See also the M68HC11
Reference Manual, (M68HC11RM/AD).
10.1.3.1
10
COPRST — Arm/reset COP timer circuitry register
COP timer arm/reset (COPRST)
State
on reset
Address
bit 7
bit 6
bit 5
bit 4
bit 3
bit 2
bit 1
bit 0
$003A
(bit 7)
(6)
(5)
(4)
(3)
(2)
(1)
(bit 0) not affected
Complete the following reset sequence to service the COP timer. Write $55 to COPRST to arm
the COP timer clearing mechanism. Then write $AA to COPRST to clear the COP timer. Executing
instructions between these two steps is possible as long as both steps are completed in the
correct sequence before the timer times out.
TPG
MC68HC11PH8
RESETS AND INTERRUPTS
MOTOROLA
10-3
185
10.1.4
Clock monitor reset
The clock monitor circuit is based on an internal RC time delay. If no MCU clock edges are
detected within this RC time delay, the clock monitor can optionally generate a system reset. The
clock monitor function is enabled or disabled by the CME control bit in the OPTION register. The
presence of a timeout is determined by the RC delay, which allows the clock monitor to operate
without any MCU clocks.
Clock monitor is used as a backup for the COP system. Because the COP needs a clock to
function, it is disabled when the clocks stop. Therefore, the clock monitor system can detect clock
failures not detected by the COP system.
Semiconductor wafer processing causes variations of the RC timeout values between individual
devices. An E clock frequency below 10 kHz is detected as a clock monitor error. An E clock
frequency of 200 kHz or more prevents clock monitor errors. Using the clock monitor function
when the E clock is below 200 kHz is not recommended.
Special considerations are needed when a STOP instruction is executed and the clock monitor is
enabled. Because the STOP function causes the clocks to be halted, the clock monitor function
generates a reset sequence if it is enabled at the time the STOP mode was initiated. Before
executing a STOP instruction, clear the CME bit in the OPTION register to zero to disable the clock
monitor. After recovery from STOP, set the CME bit to logic one to enable the clock monitor.
10.1.5
OPTION — System configuration options register 1
Address
System conÞg. options 1 (OPTION)
10
$0039
bit 6
bit 5
bit 4
bit 3
bit 2
bit 1
bit 0
State
on reset
ADPU CSEL
IRQE
DLY
CME
FCME
CR1
CR0
0001 0000
bit 7
The special-purpose OPTION register sets internal system configuration options during
initialization. The time protected control bits (IRQE, DLY, FCME and CR[1:0]) can be written to only
once in the first 64 cycles after a reset and then they become read-only bits. This minimizes the
possibility of any accidental changes to the system configuration. They may be written at any time
in special modes.
ADPU — A/D power-up (Refer to Section 9)
1 (set)
–
0 (clear) –
A/D system power enabled.
A/D system disabled, to reduce supply current.
CSEL — Clock select (Refer to Section 9)
1 (set)
–
0 (clear) –
A/D, EPROM and EEPROM use internal RC clock (about 1.5MHz).
A/D, EPROM and EEPROM use system E clock
(must be at least 1MHz).
TPG
MOTOROLA
10-4
RESETS AND INTERRUPTS
MC68HC11PH8
186
IRQE — Configure IRQ for falling edge sensitive operation (Refer to Section 3)
1 (set)
–
0 (clear) –
Falling edge sensitive operation.
Low level sensitive operation.
DLY — Enable oscillator start-up delay
1 (set)
Note:
–
A stabilization delay is imposed as the MCU is started up from STOP
mode (or from power-on reset).
0 (clear) –
The oscillator start-up delay is bypassed and the MCU resumes
processing within about four bus cycles. A stable external oscillator
is required if this option is selected.
Because DLY is set on reset, a delay is always imposed as the MCU is started up from
power-on reset.
A mask option on the MC68HC11PH8 allows the selection of either a short or long delay time for
power-on reset and exit from STOP mode; either 128 or 4064 bus cycles. This option is not
available on the MC68HC711PH8 where the delay time is 4064 bus cycles.
CME — Clock monitor enable
1 (set)
–
Clock monitor enabled.
0 (clear) –
Clock monitor disabled.
This control bit can be read or written at any time and controls whether or not the internal clock
monitor circuit triggers a reset sequence when the system clock is slow or absent. When it is clear,
the clock monitor circuit is disabled, and when it is set, the clock monitor circuit is enabled. Reset
clears the CME bit.
In order to use both STOP and clock monitor, the CME bit should be cleared before executing
STOP, then set again after recovering from STOP.
10
FCME — Force clock monitor enable
1 (set)
–
0 (clear) –
Clock monitor enabled; cannot be disabled until next reset.
Clock monitor follows the state of the CME bit.
When FCME is set, slow or stopped clocks will cause a clock failure reset sequence. To utilize
STOP mode, FCME should always be cleared.
CR[1:0] — COP timer rate select bits
The COP function can be clocked either by the internal E clock divided by 215, or by the output of
the 8-bit modulus timer A, CLK64/4. These control bits determine a scaling factor for the watchdog
timer period. See Table 10-1 and Table 10-2.
TPG
MC68HC11PH8
RESETS AND INTERRUPTS
MOTOROLA
10-5
187
10.1.6
CONFIG — Configuration control register
Address
ConÞguration control (CONFIG)
bit 7
bit 6
bit 5
bit 4
bit 3
bit 2
bit 1
bit 0
State
on reset
$003F ROMAD FREEZ CLK4X PAREN NOSEC NOCOP ROMON EEON xxxx xxxx
Among other things, CONFIG controls the presence and location of EEPROM in the memory map
and enables the COP watchdog system. A security feature that protects data in EEPROM and
RAM is available on mask programmed MCUs.
CONFIG is made up of EEPROM cells and static working latches. The operation of the MCU is
controlled directly by these latches and not the EEPROM byte. When programming the CONFIG
register, the EEPROM byte is accessed. When the CONFIG register is read, the static latches
are accessed.
These bits can be read at any time. The value read is the one latched into the register from the
EEPROM cells during the last reset sequence. A new value programmed into this register is not
readable until after a subsequent reset sequence.
On the MC68HC711PH8, and on the MC68HC11PH8 if selected by a mask option, the ROMON
bit can be written at any time if MDA = 1 (expanded mode or special test mode). It cannot be
written in bootstrap mode, and is forced to a logic one in single chip mode.
Other bits in CONFIG can be written at any time if SMOD = 1 (bootstrap or special test mode). If
SMOD = 0 (single chip or expanded mode), these bits can only be written using the EEPROM
programming sequence, and none of the bits are readable or active until latched via the next reset.
FREEZ is only active in expanded user mode.
ROMAD — ROM/EPROM mapping control (refer to Section 3)
10
1 (set)
–
0 (clear) –
ROM addressed from $4000 to $FFFF.
ROM addressed from $0000 to $BFFF (expanded mode only).
In single chip mode, reset sets this bit.
FREEZ — Expanded user mode address bus freeze (refer to Section 3)
1 (set)
–
0 (clear) –
The external bus is only active when externally mapped resources
are accessed (expanded mode only)
Normal operation.
CLK4X — 4X clock enable (refer to Section 3)
1 (set)
–
0 (clear) –
4XCLK or EXTALi driven out on the 4XOUT pin.
4XOUT pin disabled.
TPG
MOTOROLA
10-6
RESETS AND INTERRUPTS
MC68HC11PH8
188
PAREN — Pull-up assignment register enable (refer to Section 4)
1 (set)
–
0 (clear) –
PPAR register enabled; pull-ups can be enabled using PPAR.
PPAR register disabled; all pull-ups disabled.
NOSEC — EEPROM security disabled (refer to Section 3)
1 (set)
–
Disable security.
0 (clear) –
Enable security.
NOCOP — COP system disable
1 (set)
–
0 (clear) –
COP system disabled.
COP system enabled (forces reset on timeout).
ROMON — ROM/EPROM enable (refer to Section 3)
1 (set)
–
0 (clear) –
ROM/EPROM included in the memory map.
ROM/EPROM excluded from the memory map.
EEON — EEPROM enable (refer to Section 3)
1 (set)
–
0 (clear) –
10.2
EEPROM included in the memory map.
EEPROM excluded from the memory map.
Effects of reset
When a reset condition is recognized, the internal registers and control bits are forced to an initial
state. Depending on the cause of the reset and the operating mode, the reset vector can be
fetched from any of six possible locations, as shown in Table 10-3.
10
Table 10-3 Reset cause, reset vector and operating mode
Cause of reset
Normal mode vector Special test or bootstrap
POR or RESET pin
$FFFE, $FFFF
$BFFE, $BFFF
Clock monitor failure
$FFFC, $FFFD
$BFFC, $BFFD
COP watchdog timeout
$FFFA, $FFFB
$BFFA, $BFFB
These initial states then control on-chip peripheral systems to force them to known start-up states,
as described in the following paragraphs.
TPG
MC68HC11PH8
RESETS AND INTERRUPTS
MOTOROLA
10-7
189
10.2.1
Central processing unit
After reset, the CPU fetches the restart vector from the appropriate address during the first three
cycles, and begins executing instructions. The stack pointer and other CPU registers are
indeterminate immediately after reset; however, the X and I interrupt mask bits in the condition
code register (CCR) are set to mask any interrupt requests. Also, the S-bit in the CCR is set to
inhibit the STOP mode.
10.2.2
Memory map
After reset, the INIT register is initialized to $00, putting the 2K bytes of RAM at locations
$0080–$087F, and the control registers at locations $0000–$007F. The INIT2 register puts
EEPROM at locations $0D00–$0FFF.
10.2.3
Parallel I/O
When a reset occurs in expanded operating modes, port B, C, and F pins used for parallel I/O are
dedicated to the expansion bus. If a reset occurs during a single chip operating mode, all ports are
configured as general purpose high-impedance inputs.
Note:
10
Do not confuse pin function with the electrical state of the pin at reset. All
general-purpose I/O pins configured as inputs at reset are in a high-impedance state.
Port data registers reflect the port’s functional state at reset. The pin function is mode
dependent.
10.2.4
Timer
During reset, the timer system is initialized to a count of $0000. The prescaler bits are cleared,
and all output compare registers are initialized to $FFFF. All input capture registers are
indeterminate after reset. The output compare 1 mask (OC1M) register is cleared so that
successful OC1 compares do not affect any I/O pins. The other four output compares are
configured so that they do not affect any I/O pins on successful compares. All input capture
edge-detector circuits are configured for capture disabled operation. The timer overflow interrupt
flag and all eight timer function interrupt flags are cleared. All nine timer interrupts are disabled
because their mask bits have been cleared.
The I4/O5 bit in the PACTL register is cleared to configure the I4/O5 function as OC5; however,
the OM5:OL5 control bits in the TCTL1 register are clear so OC5 does not control the PA3 pin.
TPG
MOTOROLA
10-8
RESETS AND INTERRUPTS
MC68HC11PH8
190
10.2.5
Real-time interrupt (RTI)
The real-time interrupt flag (RTIF) is cleared and automatic hardware interrupts are masked. The
rate control bits are cleared after reset and can be initialized by software before the real-time
interrupt (RTI) system is used.
10.2.6
Pulse accumulator
The pulse accumulator system is disabled at reset so that the pulse accumulator input (PAI) pin
defaults to being a general-purpose input pin.
10.2.7
Computer operating properly (COP)
The COP watchdog system is enabled if the NOCOP control bit in the CONFIG register is cleared,
and disabled if NOCOP is set. The COP rate is set for the shortest duration timeout.
10.2.8
8-bit modulus timer system
On reset, the clock source for Timer A is set at EXTALi/8 and the associated modulus register is
initialized to $FF. Timers B and C are stopped on reset and pins PH6 and PH7 default to being
general purpose I/O pins.
10.2.9
Serial communications interface (SCI)
The reset condition of the SCI system is independent of the operating mode. At reset, the SCI
baud rate control register is initialized to $0004. All transmit and receive interrupts are masked and
both the transmitter and receiver are disabled so the port pins default to being general purpose
I/O lines. The SCI frame format is initialized to an 8-bit character size. The send break and receiver
wake-up functions are disabled. The TDRE and TC status bits in the SCI status register are both
set, indicating that there is no transmit data in either the transmit data register or the transmit serial
shift register. The RDRF, IDLE, OR, NF, FE, PF, and RAF receive-related status bits are cleared.
Note:
10
The foregoing paragraph also applies to SCI2. The MI BUS function is disabled, since
MIE2 is cleared on reset.
TPG
MC68HC11PH8
RESETS AND INTERRUPTS
MOTOROLA
10-9
191
10.2.10
Serial peripheral interface (SPI)
The SPI1 and SPI2 systems are disabled by reset. Their associated port pins default to being
general purpose I/O lines.
10.2.11
Analog-to-digital converter
The A/D converter configuration is indeterminate after reset. The ADPU bit is cleared by reset,
which disables the A/D system. The conversion complete flag is cleared by reset.
10.2.12
LCD module
The LCD module is disabled by reset. PB4-PB7 default to being general purpose I/O lines in single
chip mode, or higher order address outputs in expanded mode.
10.2.13
System
The EEPROM programming controls are disabled, so the memory system is configured for normal
read operation. PSEL[4:0] are initialized with the binary value %00110, causing the external IRQ
pin to have the highest I-bit interrupt priority. The IRQ pin is configured for level-sensitive operation
(for wired-OR systems). The RBOOT, SMOD, and MDA bits in the HPRIO register reflect the status
of the MODB and MODA inputs at the rising edge of reset. The DLY control bit is set to specify that
an oscillator start-up delay is imposed upon recovery from STOP mode or power-on reset. The
clock monitor system is disabled because CME and FCME are cleared.
10
TPG
MOTOROLA
10-10
RESETS AND INTERRUPTS
MC68HC11PH8
192
10.3
Reset and interrupt priority
Resets and interrupts have a hardware priority that determines which reset or interrupt is serviced
first when simultaneous requests occur. Any maskable interrupt can be given priority over other
maskable interrupts.
The first six interrupt sources are not maskable by the I-bit in the CCR. The priority arrangement
for these sources is fixed and is as follows:
1) POR or RESET pin
2) Clock monitor reset
3) COP watchdog reset
4) XIRQ interrupt
–
Illegal opcode interrupt — see Section 10.4.3 for details of handling
–
Software interrupt (SWI) — see Section 10.4.4 for details of handling
The maskable interrupt sources have the following priority arrangement:
5) IRQ
6) Real-time interrupt
7) Timer input capture 1
8) Timer input capture 2
9) Timer input capture 3
10) Timer output compare 1
11) Timer output compare 2
12) Timer output compare 3
13) Timer output compare 4
14) Timer input capture 4/output compare 5
15) SPI2 transfer complete
10
16) SCI2/MI BUS system
17) Timer overflow
18) 8-bit modulus timers
19) Pulse accumulator overflow
20) Pulse accumulator input edge
21) Wired-OR port H
22) SPI1 transfer complete
23) SCI1 system
Any one of these maskable interrupts can be assigned the highest maskable interrupt priority by
writing the appropriate value to the PSEL bits in the HPRIO register. Otherwise, the priority
arrangement remains the same. An interrupt that is assigned highest priority is still subject to
global masking by the I-bit in the CCR, or by any associated local bits. Interrupt vectors are not
affected by priority assignment. To avoid race conditions, HPRIO can only be written while I-bit
interrupts are inhibited.
TPG
MC68HC11PH8
RESETS AND INTERRUPTS
MOTOROLA
10-11
193
10.3.1
HPRIO — Highest priority I-bit interrupt and misc. register
Address
Highest priority interrupt (HPRIO)
bit 7
bit 6
$003C RBOOT SMOD
bit 5
MDA
bit 4
bit 3
bit 2
bit 1
bit 0
State
on reset
PSEL4 PSEL3 PSEL2 PSEL1 PSEL0 xxx0 0110
RBOOT, SMOD, and MDA bits depend on power-up initialization mode and can only be written in
special modes when SMOD = 1. Refer to Table 3-4.
RBOOT — Read bootstrap ROM (refer to Section 3)
1 (set)
–
0 (clear) –
Bootloader ROM enabled, at $BE40–$BFFF.
Bootloader ROM disabled and not in map.
SMOD — Special mode select (refer to Section 3)
1 (set)
–
Special mode variation in effect.
0 (clear) –
Normal mode variation in effect.
MDA — Mode select A (refer to Section 3)
1 (set)
–
0 (clear) –
Normal expanded or special test mode in effect.
Normal single chip or special bootstrap mode in effect.
PSEL[4:0] — Priority select bits
These bits select one interrupt source to be elevated above all other I-bit-related sources and can
be written to only while the I-bit in the CCR is set (interrupts disabled). See Table 10-4.
10
TPG
MOTOROLA
10-12
RESETS AND INTERRUPTS
MC68HC11PH8
194
Table 10-4 Highest priority interrupt selection
4
0
0
0
0
0
0
0
0
0
0
0
0
0
1
1
1
1
1
1
1
1
1
1
1
1
3
0
0
0
0
0
1
1
1
1
1
1
1
1
0
0
0
0
0
0
0
0
1
1
1
1
PSELx
2 1
0 X
1 0
1 0
1 1
1 1
0 0
0 0
0 1
0 1
1 0
1 0
1 1
1 1
0 0
0 0
0 1
0 1
1 0
1 0
1 1
1 1
0 0
0 0
0 1
1 X
0
X
0
1
0
1
0
1
0
1
0
1
0
1
0
1
0
1
0
1
0
1
0
1
X
X
Interrupt source promoted
Reserved (default to IRQ)
Reserved (default to IRQ)
Reserved (default to IRQ)
IRQ (external pin)
Real-time interrupt
Timer input capture 1
Timer input capture 2
Timer input capture 3
Timer output compare 1
Timer output compare 2
Timer output compare 3
Timer output compare 4
Timer output compare 5/input capture 4
Timer overßow
Pulse accumulator overßow
Pulse accumulator input edge
SPI1 serial transfer complete
SCI1 serial system
SPI2 serial transfer complete
SCI2/MI BUS serial system
8-bit modulus timers
Wired-OR port H
Reserved (default to IRQ)
Reserved (default to IRQ)
Reserved (default to IRQ)
10
TPG
MC68HC11PH8
RESETS AND INTERRUPTS
MOTOROLA
10-13
195
Table 10-5 Interrupt and reset vector assignments
Vector address
Interrupt source
FFC0, C1 Ð FFCC, CD reserved
FFCE, CF
¥ Wired-OR port H
¥ 8-bit modulus timer A underßow
FFD0, D1
¥ 8-bit modulus timer B underßow
¥ 8-bit modulus timer C underßow
¥ SCI2/MI BUS receive data register full
¥ SCI2/MI BUS receiver overrun
FFD2, D3
¥ SCI2 transmit data register empty
¥ SCI2 transmit complete
¥ SCI2 idle line detect
FFD4, D5
SPI2 serial transfer complete
¥ SCI1 receive data register full
¥ SCI1 receiver overrun
FFD6, D7
¥ SCI1 transmit data register empty
¥ SCI1 transmit complete
¥ SCI1 idle line detect
FFD8, D9
SPI1 serial transfer complete
FFDA, DB
Pulse accumulator input edge
FFDC, DD
Pulse accumulator overßow
FFDE, DF
Timer overßow
FFE0, E1
Timer input capture 4/output compare 5
FFE2, E3
Timer output compare 4
FFE4, E5
Timer output compare 3
FFE6, E7
Timer output compare 2
FFE8, E9
Timer output compare 1
FFEA, EB
Timer input capture 3
FFEC, ED
Timer input capture 2
FFEE, EF
Timer input capture 1
FFF0, F1
Real-time interrupt
FFF2, F3
IRQ pin
FFF4, F5
XIRQ pin
FFF6, F7
Software interrupt
FFF8, F9
Illegal opcode trap
FFFA, FB
COP failure
FFFC, FD
Clock monitor fail
FFFE, FF
RESET
10
CCR
Local
mask bit mask
Ñ
Ñ
I
IEH[7:0]
T8AI
I
T8BI
T8CI
RIE2
RIE2
I
TIE2
TCIE2
ILIE2
I
SP2IE
RIE
RIE
I
TIE
TCIE
ILIE
I
SPIE
I
PAII
I
PAOVI
I
TOI
I
I4/O5I
I
OC4I
I
OC3I
I
OC2I
I
OC1I
I
IC3I
I
IC2I
I
IC1I
I
RTII
I
None
X
None
None
None
None
None
None NOCOP
None
CME
None
None
TPG
MOTOROLA
10-14
RESETS AND INTERRUPTS
MC68HC11PH8
196
10.4
Interrupts
Excluding reset type interrupts, the MC68HC11PH8 has 22 interrupt vectors that support 32
interrupt sources. The 19 maskable interrupts are generated by on-chip peripheral systems.
These interrupts are recognized when the global interrupt mask bit (I) in the condition code
register (CCR) is clear. The three nonmaskable interrupt sources are illegal opcode trap, software
interrupt, and XIRQ pin. Refer to Table 10-5, which shows the interrupt sources and vector
assignments for each source.
For some interrupt sources, such as the SCI interrupts, the flags are automatically cleared during
the normal course of responding to the interrupt requests. For example, the RDRF flag in the SCI
system is cleared by the automatic clearing mechanism consisting of a read of the SCI status
register while RDRF is set, followed by a read of the SCI data register. The normal response to an
RDRF interrupt request would be to read the SCI status register to check for receive errors, then
to read the received data from the SCI data register. These two steps satisfy the automatic
clearing mechanism without requiring any special instructions.
10.4.1
Interrupt recognition and register stacking
An interrupt can be recognized at any time after it is enabled by its local mask, if any, and by the
global mask bit in the CCR. Once an interrupt source is recognized, the CPU responds at the
completion of the instruction being executed. Interrupt latency varies according to the number of
cycles required to complete the current instruction. When the CPU begins to service an interrupt,
the contents of the CPU registers are pushed onto the stack in the order shown in Table 10-6. After
the CCR value is stacked, the I-bit and the X-bit, if XIRQ is pending, are set to inhibit further
interrupts. The interrupt vector for the highest priority pending source is fetched, and execution
continues at the address specified by the vector. At the end of the interrupt service routine, the
return from interrupt instruction is executed and the saved registers are pulled from the stack in
reverse order so that normal program execution can resume. Refer to Section 11 for further
information.
10
Table 10-6 Stacking order on entry to interrupts
Memory location CPU registers
SP
PCL
SP Ð 1
PCH
SP Ð 2
IYL
SP Ð 3
IYH
SP Ð 4
IXL
SP Ð 5
IXH
SP Ð 6
ACCA
SP Ð 7
ACCB
SP Ð 8
CCR
TPG
MC68HC11PH8
RESETS AND INTERRUPTS
MOTOROLA
10-15
197
10.4.2
Nonmaskable interrupt request (XIRQ)
Nonmaskable interrupts are useful because they can always interrupt CPU operations. The most
common use for such an interrupt is for serious system problems, such as program runaway or
power failure. The XIRQ input is an updated version of the NMI (nonmaskable interrupt) input of
earlier MCUs.
Upon reset, both the X-bit and I-bit of the CCR are set to inhibit all maskable interrupts and XIRQ.
After minimum system initialization, software can clear the X-bit by a TAP instruction, enabling
XIRQ interrupts. Thereafter, software cannot set the X-bit. Thus, an XIRQ interrupt is a
nonmaskable interrupt. Because the operation of the I-bit-related interrupt structure has no effect
on the X-bit, the internal XIRQ pin remains unmasked. In the interrupt priority logic, the XIRQ
interrupt has a higher priority than any source that is maskable by the I-bit. All I-bit-related
interrupts operate normally with their own priority relationship.
When an I-bit-related interrupt occurs, the I-bit is automatically set by hardware after stacking the
CCR byte. The X-bit is not affected. When an X-bit-related interrupt occurs, both the X and I bits
are automatically set by hardware after stacking the CCR. A return from interrupt instruction
restores the X and I bits to their pre-interrupt request state.
10.4.3
10
Illegal opcode trap
Because not all possible opcodes or opcode sequences are defined, the MCU includes an illegal
opcode detection circuit, which generates an interrupt request. When an illegal opcode is detected
and the interrupt is recognized, the current value of the program counter is stacked. After interrupt
service is complete, the user should reinitialize the stack pointer to ensure that repeated execution
of illegal opcodes does not cause stack underflow. Left uninitialized, the illegal opcode vector can
point to a memory location that contains an illegal opcode. This condition causes an infinite loop
that causes stack underflow. The stack grows until the system crashes.
The illegal opcode trap mechanism works for all unimplemented opcodes on all four opcode map
pages. The address stacked as the return address for the illegal opcode interrupt is the address
of the first byte of the illegal opcode. Otherwise, it would be almost impossible to determine
whether the illegal opcode had been one or two bytes. The stacked return address can be used
as a pointer to the illegal opcode, so that the illegal opcode service routine can evaluate the
offending opcode.
10.4.4
Software interrupt
SWI is an instruction, and thus cannot be interrupted until complete. SWI is not inhibited by the
global mask bits in the CCR. Because execution of SWI sets the I mask bit, once an SWI interrupt
begins, other interrupts are inhibited until SWI is complete, or until user software clears the I bit in
the CCR.
TPG
MOTOROLA
10-16
RESETS AND INTERRUPTS
MC68HC11PH8
198
10.4.5
Maskable interrupts
The maskable interrupt structure of the MCU can be extended to include additional external
interrupt sources through the IRQ pin. The default configuration of this pin is a low-level sensitive
wired-OR network. When an event triggers an interrupt, a software accessible interrupt flag is set.
When enabled, this flag causes a constant request for interrupt service. After the flag is cleared,
the service request is released.
10.4.6
Reset and interrupt processing
The following flow diagrams illustrate the reset and interrupt process. Figure 10-1 and Figure 10-2
illustrate how the CPU begins from a reset and how interrupt detection relates to normal opcode
fetches. Figure 10-3 to Figure 10-4 provide an expanded version of a block in Figure 10-1 and illustrate
interrupt priorities. Figure 10-7 shows the resolution of interrupt sources within the SCI subsystem.
10.5
Low power operation
Both STOP and WAIT suspend CPU operation until a reset or interrupt occurs. The WAIT condition
suspends processing and reduces power consumption to an intermediate level. The STOP
condition turns off all on-chip clocks and reduces power consumption to an absolute minimum
while retaining the contents of all bytes of the RAM.
10.5.1
WAIT
The WAI opcode places the MCU in the WAIT condition, during which the CPU registers are stacked
and CPU processing is suspended until a qualified interrupt is detected. The interrupt can be an
external IRQ, an XIRQ, or any of the internally generated interrupts, such as the timer or serial
interrupts. The on-chip crystal oscillator remains active throughout the WAIT stand-by period.
10
The reduction of power in the WAIT condition depends on how many internal clock signals driving
on-chip peripheral functions can be shut down. The CPU is always shut down during WAIT. While
in the wait state, the address/data bus repeatedly runs read cycles to the address where the CCR
contents were stacked. The MCU leaves the wait state when it senses any interrupt that has not
been masked.
The PH2 clock to the free-running timer system is stopped if the I-bit is set and the COP system
is disabled by NOCOP being set. In addition, further power can be saved if the clock to the 16-bit
counter is stopped by clearing the T16EN bit in PLLCR, with the PLL active (see Section 8.1.1.1).
Several other systems can also be in a reduced power consumption state depending on the state
of software-controlled configuration control bits. Power consumption by the analog-to-digital (A/D)
converter is not affected significantly by the WAIT condition. However, the A/D converter current
TPG
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can be eliminated by writing the ADPU bit to zero and halting the RC clock (CSEL cleared). The
SPI system is enabled or disabled by the SPE control bit. The SCI transmitter is enabled or
disabled by the TE bit, and the SCI receiver is enabled or disabled by the RE bit (lowest power
consumption is achieved when RE=TE=0). Power consumption is reduced if all the PWM enable
bits (PWEN[4:1]) are cleared, thereby disabling every PWM channel. Setting the WEN bit in
PLLCR will result in WAIT mode using a slower clock and hence less power (see Section 2.5).
Therefore the power consumption in WAIT is dependent on the particular application.
10.5.2
STOP
Executing the STOP instruction while the S-bit in the CCR is clear places the MCU in the STOP
condition. If the S-bit is set, the STOP opcode is treated as a no-op (NOP). The STOP condition
offers minimum power consumption because all clocks, including the crystal oscillator, are
stopped while in this mode. To exit STOP and resume normal processing, a logic low level must
be applied to one of the external interrupts (IRQ or XIRQ) or to the RESET pin. A keyboard
interrupt on port H or a pending edge-triggered IRQ can also bring the CPU out of STOP.
Because all clocks are stopped in this mode, all internal peripheral functions also stop. The data
in the internal RAM is retained as long as VDD power is maintained. The CPU state and I/O pin
levels are static and are unchanged by STOP. Therefore, when an interrupt comes to restart the
system, the MCU resumes processing as if there were no interruption. If reset is used to restart
the system a normal reset sequence results where all I/O pins and functions are also restored to
their initial states.
10
To use the IRQ pin as a means of recovering from STOP, the I-bit in the CCR must be clear (IRQ
not masked). The XIRQ pin can be used to wake up the MCU from STOP regardless of the state
of the X-bit in the CCR, although the recovery sequence depends on the state of the X-bit. If X is
clear (XIRQ not masked), the MCU starts up, beginning with the stacking sequence leading to
normal service of the XIRQ request. If X is set (XIRQ masked or inhibited), then processing
continues with the instruction that immediately follows the STOP instruction, and no XIRQ
interrupt service is requested or pending.
Because the oscillator is stopped in STOP mode, a restart delay may be imposed to allow oscillator
stabilization upon leaving STOP. If the internal oscillator is being used, this delay is required; however,
if a stable external oscillator is being used, the DLY control bit can be used to bypass this start-up delay.
The DLY control bit is set by reset and can be optionally cleared during initialization. If the DLY equal
to zero option is used to avoid start-up delay on recovery from STOP, then reset should not be used as
the means of recovering from STOP, as this causes DLY to be set again by reset, imposing the restart
delay. This same delay also applies to power-on-reset, regardless of the state of the DLY control bit,
but does not apply to a reset while the clocks are running. See Section 3.3.2.4.
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MOTOROLA
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RESETS AND INTERRUPTS
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200
Power-on reset
(POR)
Highest
Priority
External
reset
Clock monitor fail
(CME = 1)
Delay
(128/4064 cycles )
Lowest
COP watchdog
timeout
(NOCOP = 0)
Load program counter
with contents of
$FFFE, $FFFF
(vector fetch)
Load program counter
with contents of
$FFFC, $FFFD
(vector fetch)
Load program counter
with contents of
$FFFA, $FFFB
(vector fetch)
Set S, X, and I bits
in CCR.
Reset MCU hardware
1A
Begin an instruction
sequence
Yes
10
X-bit in
CCR set?
No
XIRQ pin
low?
Yes
Stack CPU registers.
Set X and I bits.
Fetch vector at
$FFF4, $FFF5
No
See Section 10.1.5
1B
Figure 10-1 Processing flow out of reset (1 of 2)
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1B
Yes
I-bit in
CCR set?
No
I-bit interrupt
pending?
Yes
Stack
CPU registers
Yes
Stack
CPU registers
No
Fetch
opcode
Stack CPU registers.
Set I bit.
Fetch vector at
$FFF8, $FFF9
No
Legal
opcode?
Yes
WAI?
No
Stack CPU registers.
Set I bit.
Fetch vector at
$FFF6, $FFF7
10
Yes
Interrupt
yet?
SWI?
No
Restore
CPU registers
from Stack
Yes
Yes
RTI?
Set I-bit
No
Execute this
instruction
1A
No
Resolve interrupt
priority and fetch vector
for highest pending
source (Figure 10-3)
Start next instruction
sequence
Figure 10-2 Processing flow out of reset (2 of 2)
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RESETS AND INTERRUPTS
MC68HC11PH8
202
Begin
X-bit in
CCR set?
Yes
No
XIRQ pin
low?
Yes
Set X-bit in CCR.
Fetch vector at
$FFF4, $FFF5
No
Highest priority
interrupt?
Yes
Fetch vector
No
IRQ?
Fetch vector at
$FFF2, $FFF3
Yes
No
RTII = 1?
Yes
No
RTIF = 1?
Yes
Fetch vector at
$FFF0, $FFF1
Yes
Fetch vector at
$FFEE, $FFEF
Yes
Fetch vector at
$FFEC, $FFED
Yes
Fetch vector at
$FFEA, $FFEB
Yes
Fetch vector at
$FFE8, $FFE9
No
IC1I = 1?
Yes
No
IC1F = 1?
No
IC2I = 1?
Yes
No
IC2F = 1?
No
IC3I = 1?
Yes
No
IC3F = 1?
10
No
OC1I = 1?
No
Yes
OC1F = 1?
No
2A
2B
Figure 10-3 Interrupt priority resolution (1 of 3)
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203
2A
OC2I = 1?
2B
Yes
No
OC2F = 1?
Yes
Fetch vector at
$FFE6, $FFE7
Yes
Fetch vector at
$FFE4, $FFE5
Yes
Fetch vector at
$FFE2, $FFE3
Yes
Fetch vector at
$FFE0, $FFE1
Yes
Fetch vector at
$FFD4, $FFD5
No
OC3I = 1?
Yes
No
OC3F = 1?
No
Yes
OC4I = 1?
OC4F = 1?
No
No
I4/O5I = 1?
Yes
I4/O5F = 1?
No
No
SP2IE = 1?
Yes
SP2IF = 1?
No
No
MODF2 = 1?
Yes
No
SCI2
interrupt?
10
Yes
Fetch vector at
$FFD2, $FFD3
No
TOI = 1?
Yes
No
TOF = 1?
Yes
Fetch vector at
$FFDE, $FFDF
No
Modulus timer
interrupt? à
Fetch vector at
$FFD0, $FFD1
Yes
No
2C
Refer to Figure 10-6 for further details on SCI interrupts.
à Refer to Figure 10-7 for further details on modulus timer interrupts.
2D
Figure 10-4 Interrupt priority resolution (2 of 3)
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RESETS AND INTERRUPTS
MC68HC11PH8
204
2C
PAOVI = 1?
2D
Yes
No
PAII = 1?
Yes
Fetch vector at
$FFDC, $FFDD
PAIF = 1?
Yes
Fetch vector at
$FFDA, $FFDB
Yes
Fetch vector at
$FFCE, $FFCF
Yes
Fetch vector at
$FFD8, $FFD9
No
Yes
WOIF = 1?
No
No
SPIE = 1?
Yes
No
No
Wired-OR
interrupt?
PAOVF = 1?
Yes
No
SPIF = 1?
No
MODF = 1?
Yes
No
SCI1
interrupt?
No
Fetch vector at
$FFD6, $FFD7
Yes
Spurious interrupt Ñ take IRQ vector
10
Fetch vector at
$FFF2, $FFF3
Refer to Figure 10-6 for further details on SCI interrupts.
END
Figure 10-5 Interrupt priority resolution (3 of 3)
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RESETS AND INTERRUPTS
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205
Note:
Begin
RDRF = 1?
The bit names shown are for SCI1. The diagram
applies equally to SCI2, when the appropriate bit
names are substituted.
Yes
No
OR = 1?
Yes
No
TDRE = 1?
Yes
No
TIE = 1?
Yes
TCIE = 1?
RE = 1?
Yes
No
Yes
No
No
IDLE = 1?
Yes
No
No
TC = 1?
RIE = 1?
TE = 1?
Yes
No
Yes
No
Yes
ILIE = 1?
No
Yes
RE = 1?
Yes
No
No valid SCI
interrupt request
Valid SCI
interrupt request
Figure 10-6 Interrupt source resolution within the SCI subsystem
10
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RESETS AND INTERRUPTS
MC68HC11PH8
206
Begin
T8AI = 1?
Yes
No
T8BI = 1?
Yes
No
Yes
No
T8CI = 1?
T8AF = 1?
T8BF = 1?
Yes
No
Yes
No
T8CF = 1?
Yes
No
No valid modulus timer
interrupt request
Valid modulus timer
interrupt request
Figure 10-7 Interrupt source resolution within the 8-bit modulus timer subsystem
10
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THIS PAGE INTENTIONALLY LEFT BLANK
10
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RESETS AND INTERRUPTS
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11
CPU CORE AND INSTRUCTION SET
This section discusses the M68HC11 central processing unit (CPU) architecture, its addressing
modes and the instruction set. For more detailed information on the instruction set, refer to the
M68HC11 Reference Manual (M68HC11RM/AD).
The CPU is designed to treat all peripheral, I/O and memory locations identically, as addresses in
the 64Kbyte memory map. This is referred to as memory-mapped I/O. There are no special
instructions for I/O that are separate from those used for memory. This architecture also allows
accessing an operand from an external memory location with no execution-time penalty.
11.1
Registers
M68HC11 CPU registers are an integral part of the CPU and are not addressed as if they were
memory locations. The seven registers are shown in Figure 11-1 and are discussed in the
following paragraphs.
7
15
Accumulator A
0 7
Accumulator B
Double accumulator D
0
0
A:B
D
15
Index register X
0
IX
15
Index register Y
0
IY
15
Stack pointer
0
SP
15
Program counter
0
PC
Condition code register
S X H
I
N Z V C
11
CCR
Carry
Overßow
Zero
Negative
I Interrupt mask
Half carry (from bit 3)
X Interrupt mask
Stop disable
Figure 11-1 Programming model
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209
11.1.1
Accumulators A, B and D
Accumulators A and B are general purpose 8-bit registers that hold operands and results of
arithmetic calculations or data manipulations. For some instructions, these two accumulators are
treated as a single double-byte (16-bit) accumulator called accumulator D. Although most
operations can use accumulators A or B interchangeably, the following exceptions apply:
•
The ABX and ABY instructions add the contents of 8-bit accumulator B to the contents of 16-bit
register X or Y, but there are no equivalent instructions that use A instead of B.
•
The TAP and TPA instructions transfer data from accumulator A to the condition code register,
or from the condition code register to accumulator A, however, there are no equivalent
instructions that use B rather than A.
•
The decimal adjust accumulator A (DAA) instruction is used after binary-coded decimal (BCD)
arithmetic operations, but there is no equivalent BCD instruction to adjust accumulator B.
•
The add, subtract, and compare instructions associated with both A and B (ABA, SBA, and
CBA) only operate in one direction, making it important to plan ahead to ensure the correct
operand is in the correct accumulator.
11.1.2
Index register X (IX)
The IX register provides a 16-bit indexing value that can be added to the 8-bit offset provided in
an instruction to create an effective address. The IX register can also be used as a counter or as
a temporary storage register.
11.1.3
11
Index register Y (IY)
The 16-bit IY register performs an indexed mode function similar to that of the IX register.
However, most instructions using the IY register require an extra byte of machine code and an
extra cycle of execution time because of the way the opcode map is implemented. Refer to Section
11.3 for further information.
11.1.4
Stack pointer (SP)
The M68HC11 CPU has an automatic program stack. This stack can be located anywhere in the
address space and can be any size up to the amount of memory available in the system. Normally
the SP is initialized by one of the first instructions in an application program. The stack is
configured as a data structure that grows downward from high memory to low memory. Each time
a new byte is pushed onto the stack, the SP is decremented. Each time a byte is pulled from the
stack, the SP is incremented. At any given time, the SP holds the 16-bit address of the next free
location in the stack. Figure 11-2 is a summary of SP operations.
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CPU CORE AND INSTRUCTION SET
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210
JSR, Jump to subroutine
BSR, Branch to subroutine
Main program
PC
DIRECT
RTN
Stack
Main program
PC
$9D = JSR
dd
Next instruction
$8D = BSR
rr
Next instruction
RTN
SPÐ2
SPÐ1
SP
RTNH
RTNL
Main program
PC
IND, X
RTN
$AD = JSR
ff
Next instruction
Main program
PC
IND, Y
RTN
$18 = PRE
$AD = JSR
ff
Next instruction
SWI, Software interrupt
Main program
Stack
SPÐ2
SPÐ1
SP
RTNH
RTNL
PC
RTN
$3F = SWI
WAI, Wait for interrupt
Main program
Main program
PC
EXTEND
RTN
PC
RTN
$BD = JSR
hh
ll
Next instruction
$3E = WAI
Stack
SPÐ9
SPÐ8
SPÐ7
SPÐ6
SPÐ5
SPÐ4
SPÐ3
SPÐ2
SPÐ1
SP
Condition Code
Accumulator B
Accumulator A
Index register (IXH)
Index register (IXL)
Index register (IYH)
Index register (IYL)
RTNH
RTNL
RTI, Return from interrupt
Interrupt program
PC
$3B = RTI
RTS, Return from subroutine
Main program
PC
$39 = RTS
Stack
SP
SP+1
SP+2
RTNH
RTNL
Stack
SP
SP+1
SP+2
SP+3
SP+4
SP+5
SP+6
SP+7
SP+8
SP+9
Condition Code
Accumulator B
Accumulator A
Index register (IXH)
Index register (IXL)
Index register (IYH)
Index register (IYL)
RTNH
RTNL
11
LEGEND
RTN Address of the next instruction in the main program, to be executed on return from subroutine
RTNH More signiÞcant byte of return address
RTNL Less signiÞcant byte of return address
Shaded cells show stack pointer position after the operation is complete
dd 8-bit direct address ($0000Ð$00FF); the high byte is assumed to be $00
ff 8-bit positive offset ($00 to $FF (0 to 256)) is added to the index register contents
hh High order byte of 16-bit extended address
ll Low order byte of 16-bit extended address
rr Signed relative offset ($80 to $7F (Ð128 to +127)); offset is relative to the address following the offset byte
Figure 11-2 Stacking operations
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211
When a subroutine is called by a jump to subroutine (JSR) or branch to subroutine (BSR)
instruction, the address of the instruction after the JSR or BSR is automatically pushed onto the
stack, less significant byte first. When the subroutine is finished, a return from subroutine (RTS)
instruction is executed. The RTS pulls the previously stacked return address from the stack, and
loads it into the program counter. Execution then continues at this recovered return address.
When an interrupt is recognized, the current instruction finishes normally, the return address (the
current value in the program counter) is pushed onto the stack, all of the CPU registers are pushed
onto the stack, and execution continues at the address specified by the vector for the interrupt. At
the end of the interrupt service routine, an RTI instruction is executed. The RTI instruction causes
the saved registers to be pulled off the stack in reverse order. Program execution resumes at the
return address.
There are instructions that push and pull the A and B accumulators and the X and Y index
registers. These instructions are often used to preserve program context. For example, pushing
accumulator A onto the stack when entering a subroutine that uses accumulator A, and then
pulling accumulator A off the stack just before leaving the subroutine, ensures that the contents of
a register will be the same after returning from the subroutine as it was before starting the
subroutine.
11.1.5
Program counter (PC)
The program counter, a 16-bit register, contains the address of the next instruction to be executed.
After reset, the program counter is initialized from one of six possible vectors, depending on
operating mode and the cause of reset.
Table 11-1 Reset vector comparison
Normal
Test or Boot
POR or RESET pin
$FFFE, $FFFF
$BFFE, $BFFF
Clock monitor
$FFFC, $FFFD
$BFFE, $BFFF
COP watchdog
$FFFA, $FFFB
$BFFE, $BFFF
11
11.1.6
Condition code register (CCR)
This 8-bit register contains five condition code indicators (C, V, Z, N, and H), two interrupt masking
bits, (IRQ and XIRQ) and a stop disable bit (S). In the M68HC11 CPU, condition codes are
automatically updated by most instructions. For example, load accumulator A (LDAA) and store
accumulator A (STAA) instructions automatically set or clear the N, Z, and V condition code flags.
Pushes, pulls, add B to X (ABX), add B to Y (ABY), and transfer/exchange instructions do not affect
the condition codes. Refer to Table 11-2, which shows the condition codes that are affected by a
particular instruction.
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11.1.6.1
Carry/borrow (C)
The C-bit is set if the arithmetic logic unit (ALU) performs a carry or borrow during an arithmetic
operation. The C-bit also acts as an error flag for multiply and divide operations. Shift and rotate
instructions operate with and through the carry bit to facilitate multiple-word shift operations.
11.1.6.2
Overflow (V)
The overflow bit is set if an operation causes an arithmetic overflow. Otherwise, the V-bit is cleared.
11.1.6.3
Zero (Z)
The Z-bit is set if the result of an arithmetic, logic, or data manipulation operation is zero.
Otherwise, the Z-bit is cleared. Compare instructions do an internal implied subtraction and the
condition codes, including Z, reflect the results of that subtraction. A few operations (INX, DEX,
INY, and DEY) affect the Z-bit and no other condition flags. For these operations, only = and ≠
conditions can be determined.
11.1.6.4
Negative (N)
The N-bit is set if the result of an arithmetic, logic, or data manipulation operation is negative;
otherwise, the N-bit is cleared. A result is said to be negative if its most significant bit (MSB) is set
(MSB = 1). A quick way to test whether the contents of a memory location has the MSB set is to
load it into an accumulator and then check the status of the N-bit.
11.1.6.5
Interrupt mask (I)
The interrupt request (IRQ) mask (I-bit) is a global mask that disables all maskable interrupt
sources. While the I-bit is set, interrupts can become pending, but the operation of the CPU
continues uninterrupted until the I-bit is cleared. After any reset, the I-bit is set by default and can
only be cleared by a software instruction. When an interrupt is recognized, the I-bit is set after the
registers are stacked, but before the interrupt vector is fetched. After the interrupt has been
serviced, a return from interrupt instruction is normally executed, restoring the registers to the
values that were present before the interrupt occurred. Normally, the I-bit is zero after a return from
interrupt is executed. Although the I-bit can be cleared within an interrupt service routine, ‘nesting’
interrupts in this way should only be done when there is a clear understanding of latency and of
the arbitration mechanism. Refer to Section 10.
11
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11.1.6.6
Half carry (H)
The H-bit is set when a carry occurs between bits 3 and 4 of the arithmetic logic unit during an
ADD, ABA, or ADC instruction. Otherwise, the H-bit is cleared. Half carry is used during BCD
operations.
11.1.6.7
X interrupt mask (X)
The XIRQ mask (X) bit disables interrupts from the XIRQ pin. After any reset, X is set by default
and must be cleared by a software instruction. When an XIRQ interrupt is recognized, the X- and
I-bits are set after the registers are stacked, but before the interrupt vector is fetched. After the
interrupt has been serviced, an RTI instruction is normally executed, causing the registers to be
restored to the values that were present before the interrupt occurred. The X interrupt mask bit is
set only by hardware RESET or XIRQ acknowledge). X is cleared only by program instruction
(TAP, where the associated bit of A is 0; or RTI, where bit 6 of the value loaded into the CCR from
the stack has been cleared). There is no hardware action for clearing X.
11.1.6.8
Stop disable (S)
Setting the STOP disable (S) bit prevents the STOP instruction from putting the M68HC11 into a
low-power stop condition. If the STOP instruction is encountered by the CPU while the S-bit is set,
it is treated as a no-operation (NOP) instruction, and processing continues to the next instruction.
S is set by reset — STOP disabled by default.
11.2
Data types
The M68HC11 CPU supports the following data types:
11
•
Bit data
•
8-bit and 16-bit signed and unsigned integers
•
16-bit unsigned fractions
•
16-bit addresses
A byte is eight bits wide and can be accessed at any byte location. A word is composed of two
consecutive bytes with the most significant byte at the lower value address. Because the
M68HC11 is an 8-bit CPU, there are no special requirements for alignment of instructions or
operands.
TPG
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CPU CORE AND INSTRUCTION SET
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11.3
Opcodes and operands
The M68HC11 family of microcontrollers uses 8-bit opcodes. Each opcode identifies a particular
instruction and associated addressing mode to the CPU. Several opcodes are required to provide
each instruction with a range of addressing capabilities. Only 256 opcodes would be available if
the range of values were restricted to the number able to be expressed in 8-bit binary numbers.
A four-page opcode map has been implemented to expand the number of instructions. An
additional byte, called a prebyte, directs the processor from page 0 of the opcode map to one of
the other three pages. As its name implies, the additional byte precedes the opcode.
A complete instruction consists of a prebyte, if any, an opcode, and zero, one, two, or three
operands. The operands contain information the CPU needs for executing the instruction.
Complete instructions can be from one to five bytes long.
11.4
Addressing modes
Six addressing modes; immediate, direct, extended, indexed, inherent, and relative, detailed in the
following paragraphs, can be used to access memory. All modes except inherent mode use an
effective address. The effective address is the memory address from which the argument is
fetched or stored, or the address from which execution is to proceed. The effective address can
be specified within an instruction, or it can be calculated.
11.4.1
Immediate (IMM)
In the immediate addressing mode an argument is contained in the byte(s) immediately following
the opcode. The number of bytes following the opcode matches the size of the register or memory
location being operated on. There are two, three, and four (if prebyte is required) byte immediate
instructions. The effective address is the address of the byte following the instruction.
11.4.2
11
Direct (DIR)
In the direct addressing mode, the low-order byte of the operand address is contained in a single
byte following the opcode, and the high-order byte of the address is assumed to be $00.
Addresses $00–$FF are thus accessed directly, using two-byte instructions. Execution time is
reduced by eliminating the additional memory access required for the high-order address byte. In
most applications, this 256-byte area is reserved for frequently referenced data. In M68HC11
MCUs, the memory map can be configured for combinations of internal registers, RAM, or
external memory to occupy these addresses.
TPG
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11.4.3
Extended (EXT)
In the extended addressing mode, the effective address of the argument is contained in two bytes
following the opcode byte. These are three-byte instructions (or four-byte instructions if a prebyte
is required). One or two bytes are needed for the opcode and two for the effective address.
11.4.4
Indexed (IND, X; IND, Y)
In the indexed addressing mode, an 8-bit unsigned offset contained in the instruction is added to
the value contained in an index register (IX or IY) — the sum is the effective address. This
addressing mode allows referencing any memory location in the 64Kbyte address space. These
are two- to five-byte instructions, depending on whether or not a prebyte is required.
11.4.5
Inherent (INH)
In the inherent addressing mode, all the information necessary to execute the instruction is
contained in the opcode. Operations that use only the index registers or accumulators, as well as
control instructions with no arguments, are included in this addressing mode. These are one or
two-byte instructions.
11.4.6
Relative (REL)
The relative addressing mode is used only for branch instructions. If the branch condition is true,
an 8-bit signed offset included in the instruction is added to the contents of the program counter
to form the effective branch address. Otherwise, control proceeds to the next instruction. These
are usually two-byte instructions.
11
11.5
Instruction set
Refer to Table 11-2, which shows all the M68HC11 instructions in all possible addressing modes.
For each instruction, the table shows the operand construction, the number of machine code
bytes, and execution time in CPU E clock cycles.
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Table 11-2 Instruction set (Sheet 1 of 6)
Addressing
mode
Mnemonic
Operation
Description
ABA
Add accumulators
A+B⇒A
INH
ABX
Add B to X
IX + (00:B) ⇒ IX
ABY
Add B to Y
IY + (00:B) ⇒ IY
ADCA (opr)
Add with carry to A
A+M+C⇒A
ADCB (opr)
Add with carry to B
ADDA (opr)
Instruction
Opcode
Operand
Condition codes
Cycles
S X H
I
N Z V C
1B
Ñ
2
Ñ Ñ ∆ Ñ ∆ ∆ ∆ ∆
INH
3A
Ñ
3
Ñ Ñ Ñ Ñ Ñ Ñ Ñ Ñ
INH
18 3A
Ñ
4
Ñ Ñ Ñ Ñ Ñ Ñ Ñ Ñ
A
A
A
A
A
IMM
DIR
EXT
IND, X
IND, Y
89
99
B9
A9
18 A9
ii
dd
hh ll
ff
ff
2
3
4
4
5
Ñ Ñ ∆ Ñ ∆ ∆ ∆ ∆
B+M+C⇒B
B
B
B
B
B
IMM
DIR
EXT
IND, X
IND, Y
C9
D9
F9
E9
18 E9
ii
dd
hh ll
ff
ff
2
3
4
4
5
Ñ Ñ ∆ Ñ ∆ ∆ ∆ ∆
Add memory to A
A+M⇒A
A
A
A
A
A
IMM
DIR
EXT
IND, X
IND, Y
8B
9B
BB
AB
18 AB
ii
dd
hh ll
ff
ff
2
3
4
4
5
Ñ Ñ ∆ Ñ ∆ ∆ ∆ ∆
ADDB (opr)
Add memory to B
B+M⇒B
B
B
B
B
B
IMM
DIR
EXT
IND, X
IND, Y
CB
DB
FB
EB
18 EB
ii
dd
hh ll
ff
ff
2
3
4
4
5
Ñ Ñ ∆ Ñ ∆ ∆ ∆ ∆
ADDD (opr)
Add 16-bit to D
D + (M:M+1) ⇒ D
IMM
DIR
EXT
IND, X
IND, Y
C3
D3
F3
E3
18 E3
jj kk
dd
hh ll
ff
ff
4
5
6
6
7
Ñ Ñ Ñ Ñ ∆ ∆ ∆ ∆
ANDA (opr)
AND A with memory
A¥M⇒A
A
A
A
A
A
IMM
DIR
EXT
IND, X
IND, Y
84
94
B4
A4
18 A4
ii
dd
hh ll
ff
ff
2
3
4
4
5
Ñ Ñ Ñ Ñ ∆ ∆ 0 Ñ
ANDB (opr)
AND B with memory
B¥M⇒B
B
B
B
B
B
IMM
DIR
EXT
IND, X
IND, Y
C4
D4
F4
E4
18 E4
ii
dd
hh ll
ff
ff
2
3
4
4
5
Ñ Ñ Ñ Ñ ∆ ∆ 0 Ñ
ASL (opr)
Arithmetic shift left
EXT
IND, X
IND, Y
78
68
18 68
hh ll
ff
ff
6
6
7
Ñ Ñ Ñ Ñ ∆ ∆ ∆ ∆
ASLA
Arithmetic shift left A
ASLB
Arithmetic shift left B
ASLD
Arithmetic shift left D
0
C
b7
b0
A
INH
48
Ñ
2
Ñ Ñ Ñ Ñ ∆ ∆ ∆ ∆
B
INH
58
Ñ
2
Ñ Ñ Ñ Ñ ∆ ∆ ∆ ∆
INH
05
Ñ
3
Ñ Ñ Ñ Ñ ∆ ∆ ∆ ∆
hh ll
ff
ff
6
6
7
Ñ Ñ Ñ Ñ ∆ ∆ ∆ ∆
Ñ Ñ Ñ Ñ ∆ ∆ ∆ ∆
0
C
b15
b0
ASR
Arithmetic shift right
ASRA
Arithmetic shift right A
ASRB
Arithmetic shift right B
BCC (rel)
Branch if carry clear
C=0?
BCLR (opr)
(msk)
Clear bit(s)
M ¥ (mm) ⇒ M
EXT
IND, X
IND, Y
C
b7
b0
77
67
18 67
A
INH
47
Ñ
2
B
INH
57
Ñ
2
Ñ Ñ Ñ Ñ ∆ ∆ ∆ ∆
REL
24
rr
3
Ñ Ñ Ñ Ñ Ñ Ñ Ñ Ñ
dd mm
ff mm
ff mm
6
7
8
Ñ Ñ Ñ Ñ ∆ ∆ 0 Ñ
DIR
IND, X
IND, Y
15
1D
18 1D
BCS (rel)
Branch if carry set
C=1?
REL
25
rr
3
Ñ Ñ Ñ Ñ Ñ Ñ Ñ Ñ
BEQ (rel)
Branch if equal to zero
Z=1?
REL
27
rr
3
Ñ Ñ Ñ Ñ Ñ Ñ Ñ Ñ
BGE (rel)
Branch if ≥ zero
N⊕V=0?
REL
2C
rr
3
Ñ Ñ Ñ Ñ Ñ Ñ Ñ Ñ
BGT (rel)
Branch if > zero
Z + (N ⊕ V) = 0 ?
REL
2E
rr
3
Ñ Ñ Ñ Ñ Ñ Ñ Ñ Ñ
BHI (rel)
Branch if higher
C+Z=0?
REL
22
rr
3
Ñ Ñ Ñ Ñ Ñ Ñ Ñ Ñ
11
TPG
MC68HC11PH8
CPU CORE AND INSTRUCTION SET
MOTOROLA
11-9
217
Table 11-2 Instruction set (Sheet 2 of 6)
11
Addressing
mode
Mnemonic
Operation
Description
BHS (rel)
Branch if higher or same
C=0?
BITA (opr)
Bit(s) test A with memory
A¥M
A
A
A
A
A
IMM
DIR
EXT
IND, X
IND, Y
BITB (opr)
Bit(s) test B with memory
B¥M
B
B
B
B
B
IMM
DIR
EXT
IND, X
IND, Y
REL
Instruction
Opcode
24
Operand
Condition codes
Cycles
S X H
I
N Z V C
rr
3
Ñ Ñ Ñ Ñ Ñ Ñ Ñ Ñ
85
95
B5
A5
18 A5
ii
dd
hh ll
ff
ff
2
3
4
4
5
Ñ Ñ Ñ Ñ ∆ ∆ 0 Ñ
C5
D5
F5
E5
18 E5
ii
dd
hh ll
ff
ff
2
3
4
4
5
Ñ Ñ Ñ Ñ ∆ ∆ 0 Ñ
BLE (rel)
Branch if ≤ zero
Z + (N ⊕ V) = 1 ?
REL
2F
rr
3
Ñ Ñ Ñ Ñ Ñ Ñ Ñ Ñ
BLO (rel)
Branch if lower
C=1?
REL
25
rr
3
Ñ Ñ Ñ Ñ Ñ Ñ Ñ Ñ
BLS (rel)
Branch if lower or same
C+Z=1?
REL
23
rr
3
Ñ Ñ Ñ Ñ Ñ Ñ Ñ Ñ
BLT (rel)
Branch if < zero
N⊕V=1?
REL
2D
rr
3
Ñ Ñ Ñ Ñ Ñ Ñ Ñ Ñ
BMI (rel)
Branch if minus
N=1?
REL
2B
rr
3
Ñ Ñ Ñ Ñ Ñ Ñ Ñ Ñ
BNE (rel)
Branch if ≠ zero
Z=0?
REL
26
rr
3
Ñ Ñ Ñ Ñ Ñ Ñ Ñ Ñ
BPL(rel)
Branch if plus
N=0?
REL
2A
rr
3
Ñ Ñ Ñ Ñ Ñ Ñ Ñ Ñ
REL
20
rr
3
Ñ Ñ Ñ Ñ Ñ Ñ Ñ Ñ
6
7
8
Ñ Ñ Ñ Ñ Ñ Ñ Ñ Ñ
BRA (rel)
Branch always
1=1?
BRCLR(opr)
(msk)
(rel)
Branch if bit(s) clear
M ¥ mm = 0 ?
DIR
IND, X
IND, Y
REL
13
1F
18 1F
21
dd mm rr
ff mm rr
ff mm rr
BRN (rel)
Branch never
1=0?
3
Ñ Ñ Ñ Ñ Ñ Ñ Ñ Ñ
BRSET(opr)
(msk)
(rel)
Branch if bit(s) set
M ¥ mm = 0 ?
DIR
IND, X
IND, Y
12
1E
18 1E
dd mm rr
ff mm rr
ff mm rr
rr
6
7
8
Ñ Ñ Ñ Ñ Ñ Ñ Ñ Ñ
BSET (opr)
(msk)
Set bit(s)
M + mm ⇒ M
DIR
IND, X
IND, Y
14
1C
18 1C
dd mm
ff mm
ff mm
6
7
8
Ñ Ñ Ñ Ñ ∆ ∆ 0 Ñ
BSR (rel)
Branch to subroutine
see Figure 11-2
REL
8D
rr
6
Ñ Ñ Ñ Ñ Ñ Ñ Ñ Ñ
BVC (rel)
Branch if overßow clear
V=0?
REL
28
rr
3
Ñ Ñ Ñ Ñ Ñ Ñ Ñ Ñ
BVS (rel)
Branch if overßow set
V=1?
REL
29
rr
3
Ñ Ñ Ñ Ñ Ñ Ñ Ñ Ñ
CBA
Compare A with B
AÐB
INH
11
Ñ
2
Ñ Ñ Ñ Ñ ∆ ∆ ∆ ∆
CLC
Clear carry bit
0⇒C
INH
0C
Ñ
2
Ñ Ñ Ñ Ñ Ñ Ñ Ñ 0
0E
Ñ
2
Ñ Ñ Ñ 0 Ñ Ñ Ñ Ñ
hh ll
ff
ff
6
6
7
Ñ Ñ Ñ Ñ 0 1 0 0
CLI
Clear interrupt mask
0⇒I
INH
CLR (opr)
Clear memory byte
0⇒M
DIR
IND, X
IND, Y
CLRA
Clear accumulator A
0⇒A
A
INH
4F
Ñ
2
Ñ Ñ Ñ Ñ 0 1 0 0
CLRB
Clear accumulator B
0⇒B
B
INH
5F
Ñ
2
Ñ Ñ Ñ Ñ 0 1 0 0
CLV
Clear overßow ßag
0⇒V
INH
0A
Ñ
2
Ñ Ñ Ñ Ñ Ñ Ñ 0 Ñ
CMPA (opr)
Compare A with memory
AÐM
A
A
A
A
A
IMM
DIR
EXT
IND, X
IND, Y
81
91
B1
A1
18 A1
ii
dd
hh ll
ff
ff
2
3
4
4
5
Ñ Ñ Ñ Ñ ∆ ∆ ∆ ∆
CMPB (opr)
Compare B with memory
BÐM
B
B
B
B
B
IMM
DIR
EXT
IND, X
IND, Y
C1
D1
F1
E1
18 E1
ii
dd
hh ll
ff
ff
2
3
4
4
5
Ñ Ñ Ñ Ñ ∆ ∆ ∆ ∆
COM (opr)
Ones complement memory byte
$FF Ð M ⇒ M
EXT
IND, X
IND, Y
73
63
18 63
hh ll
ff
ff
6
6
7
Ñ Ñ Ñ Ñ ∆ ∆ 0 1
7F
6F
18 6F
COMA
Ones complement A
$FF Ð A ⇒ A
A
INH
43
Ñ
2
Ñ Ñ Ñ Ñ ∆ ∆ 0 1
COMB
Ones complement B
$FF Ð B ⇒ B
B
INH
53
Ñ
2
Ñ Ñ Ñ Ñ ∆ ∆ 0 1
TPG
MOTOROLA
11-10
CPU CORE AND INSTRUCTION SET
MC68HC11PH8
218
Table 11-2 Instruction set (Sheet 3 of 6)
Mnemonic
Operation
Description
CPD (opr)
Compare D with memory (16-bit)
D Ð (M:M+1)
CPX (opr)
Compare IX with memory (16-bit)
CPY (opr)
Addressing
mode
Instruction
Condition codes
Opcode
Operand
Cycles
IMM
DIR
EXT
IND, X
IND, Y
1A
1A
1A
1A
CD
83
93
B3
A3
A3
jj kk
dd
hh ll
ff
ff
5
6
7
7
7
Ñ Ñ Ñ Ñ ∆ ∆ ∆ ∆
IX Ð (M:M+1)
IMM
DIR
EXT
IND, X
IND, Y
8C
9C
BC
AC
CD AC
jj kk
dd
hh ll
ff
ff
4
5
6
6
7
Ñ Ñ Ñ Ñ ∆ ∆ ∆ ∆
Compare IY with memory (16-bit)
IY Ð (M:M+1)
IMM
DIR
EXT
IND, X
IND, Y
18
18
18
1A
18
jj kk
dd
hh ll
ff
ff
5
6
7
7
7
Ñ Ñ Ñ Ñ ∆ ∆ ∆ ∆
DAA
Decimal adjust A
adjust sum to BCD
DEC (opr)
Decrement memory byte
MÐ1⇒M
INH
EXT
IND, X
IND, Y
8C
9C
BC
AC
AC
19
7A
6A
18 6A
S X H
I
N Z V C
Ñ
2
Ñ Ñ Ñ Ñ ∆ ∆ ? ∆
hh ll
ff
ff
6
6
7
Ñ Ñ Ñ Ñ ∆ ∆ ∆ Ñ
DECA
Decrement accumulator A
AÐ1⇒A
A
INH
4A
Ñ
2
Ñ Ñ Ñ Ñ ∆ ∆ ∆ Ñ
DECB
Decrement accumulator B
BÐ1⇒B
B
INH
5A
Ñ
2
Ñ Ñ Ñ Ñ ∆ ∆ ∆ Ñ
DES
Decrement stack pointer
SP Ð 1 ⇒ SP
INH
34
Ñ
3
Ñ Ñ Ñ Ñ Ñ Ñ Ñ Ñ
DEX
Decrement index register X
IX Ð 1 ⇒ IX
INH
09
Ñ
3
Ñ Ñ Ñ Ñ Ñ ∆ Ñ Ñ
DEY
Decrement index register Y
IY Ð 1 ⇒ IY
INH
18 09
Ñ
4
Ñ Ñ Ñ Ñ Ñ ∆ Ñ Ñ
EORA (opr)
Exclusive OR A with memory
A⊕M⇒A
A
A
A
A
A
IMM
DIR
EXT
IND, X
IND, Y
88
98
B8
A8
18 A8
ii
dd
hh ll
ff
ff
2
3
4
4
5
Ñ Ñ Ñ Ñ ∆ ∆ 0 Ñ
EORB (opr)
Exclusive OR B with memory
B⊕M⇒A
B
B
B
B
B
IMM
DIR
EXT
IND, X
IND, Y
C8
D8
F8
E8
18 E8
ii
dd
hh ll
ff
ff
2
3
4
4
5
Ñ Ñ Ñ Ñ ∆ ∆ 0 Ñ
FDIV
Fractional divide, 16 by 16
D / IX ⇒ IX; r ⇒ D
INH
03
Ñ
41
Ñ Ñ Ñ Ñ Ñ ∆ ∆ ∆
IDIV
Integer divide, 16 by 16
D / IX ⇒ IX; r ⇒ D
INH
02
Ñ
41
Ñ Ñ Ñ Ñ Ñ ∆ 0 ∆
INC (opr)
Increment memory byte
M+1⇒M
hh ll
ff
ff
6
6
7
Ñ Ñ Ñ Ñ ∆ ∆ ∆ Ñ
EXT
IND, X
IND, Y
7C
6C
18 6C
INCA
Increment accumulator A
A+1⇒A
A
INH
4C
Ñ
2
Ñ Ñ Ñ Ñ ∆ ∆ ∆ Ñ
INCB
Increment accumulator B
B+1⇒B
B
INH
5C
Ñ
2
Ñ Ñ Ñ Ñ ∆ ∆ ∆ Ñ
INS
Increment stack pointer
SP + 1 ⇒ SP
INH
31
Ñ
3
Ñ Ñ Ñ Ñ Ñ Ñ Ñ Ñ
INX
Increment index register X
IX + 1 ⇒ IX
INH
08
Ñ
3
Ñ Ñ Ñ Ñ Ñ ∆ Ñ Ñ
INY
Increment index register Y
IY + 1 ⇒ IY
INH
18 08
Ñ
4
Ñ Ñ Ñ Ñ Ñ ∆ Ñ Ñ
JMP (opr)
Jump
see Figure 11-2
EXT
IND, X
IND, Y
7E
6E
18 6E
hh ll
ff
ff
3
3
4
Ñ Ñ Ñ Ñ Ñ Ñ Ñ Ñ
JSR (opr)
Jump to subroutine
see Figure 11-2
DIR
EXT
IND, X
IND, Y
9D
BD
AD
18 AD
dd
hh ll
ff
ff
5
6
6
7
Ñ Ñ Ñ Ñ Ñ Ñ Ñ Ñ
LDAA (opr)
Load accumulator A
M⇒A
IMM
DIR
EXT
IND, X
IND, Y
86
96
B6
A6
18 A6
ii
dd
hh ll
ff
ff
2
3
4
4
5
Ñ Ñ Ñ Ñ ∆ ∆ 0 Ñ
A
A
A
A
A
11
TPG
MC68HC11PH8
CPU CORE AND INSTRUCTION SET
MOTOROLA
11-11
219
Table 11-2 Instruction set (Sheet 4 of 6)
Condition codes
Opcode
Operand
IMM
DIR
EXT
IND, X
IND, Y
C6
D6
F6
E6
18 E6
ii
dd
hh ll
ff
ff
2
3
4
4
5
Ñ Ñ Ñ Ñ ∆ ∆ 0 Ñ
M ⇒ A; M+1 ⇒ B
IMM
DIR
EXT
IND, X
IND, Y
CC
DC
FC
EC
18 EC
jj kk
dd
hh ll
ff
ff
3
4
5
5
6
Ñ Ñ Ñ Ñ ∆ ∆ 0 Ñ
Load stack pointer
M:M+1 ⇒ SP
IMM
DIR
EXT
IND, X
IND, Y
8E
9E
BE
AE
18 AE
jj kk
dd
hh ll
ff
ff
3
4
5
5
6
Ñ Ñ Ñ Ñ ∆ ∆ 0 Ñ
LDX (opr)
Load index register X
M:M+1 ⇒ IX
IMM
DIR
EXT
IND, X
IND, Y
CE
DE
FE
EE
CD EE
jj kk
dd
hh ll
ff
ff
3
4
5
5
6
Ñ Ñ Ñ Ñ ∆ ∆ 0 Ñ
LDY (opr)
Load index register Y
M:M+1 ⇒ IY
IMM
DIR
EXT
IND, X
IND, Y
18
18
18
1A
18
jj kk
dd
hh ll
ff
ff
4
5
6
6
6
Ñ Ñ Ñ Ñ ∆ ∆ 0 Ñ
LSL (opr)
Logical shift left
EXT
IND, X
IND, Y
78
68
18 68
hh ll
ff
ff
6
6
7
Ñ Ñ Ñ Ñ ∆ ∆ ∆ ∆
Operation
Description
LDAB (opr)
Load accumulator B
M⇒B
LDD (opr)
Load double accumulator D
LDS (opr)
B
B
B
B
B
0
C
LSLA
Logical shift left A
LSLB
Logical shift Left B
LSLD
Logical shift left D
b7
b0
C
b15
LSR (opr)
Logical shift right
LSRA
Logical shift right A
LSRB
Logical shift right B
LSRD
Logical shift right D
CE
DE
FE
EE
EE
Cycles
S X H
I
N Z V C
A
INH
48
Ñ
2
Ñ Ñ Ñ Ñ ∆ ∆ ∆ ∆
B
INH
58
Ñ
2
Ñ Ñ Ñ Ñ ∆ ∆ ∆ ∆
0
INH
05
Ñ
3
Ñ Ñ Ñ Ñ ∆ ∆ ∆ ∆
hh ll
ff
ff
6
6
7
Ñ Ñ Ñ Ñ 0 ∆ ∆ ∆
C
EXT
IND, X
IND, Y
b0
0
b7
b0
0
74
64
18 64
A
INH
44
Ñ
2
Ñ Ñ Ñ Ñ 0 ∆ ∆ ∆
B
INH
54
Ñ
2
Ñ Ñ Ñ Ñ 0 ∆ ∆ ∆
INH
04
Ñ
3
Ñ Ñ Ñ Ñ 0 ∆ ∆ ∆
C
b15
11
Instruction
Addressing
mode
Mnemonic
b0
MUL
Multiply, 8 x 8
A*B⇒D
INH
NEG (opr)
Twos complement memory byte
0ÐM⇒M
EXT
IND, X
IND, Y
Ñ
10
Ñ Ñ Ñ Ñ Ñ Ñ Ñ ∆
hh ll
ff
ff
6
6
7
Ñ Ñ Ñ Ñ ∆ ∆ ∆ ∆
NEGA
Twos complement A
0ÐA⇒A
A
INH
NEGB
Twos complement B
0ÐB⇒B
B
INH
40
Ñ
2
Ñ Ñ Ñ Ñ ∆ ∆ ∆ ∆
50
Ñ
2
NOP
No operation
no operation
INH
Ñ Ñ Ñ Ñ ∆ ∆ ∆ ∆
01
Ñ
2
Ñ Ñ Ñ Ñ Ñ Ñ Ñ Ñ
ORAA
OR accumulator A (inclusive)
A+M⇒A
A
A
A
A
A
IMM
DIR
EXT
IND, X
IND, Y
8A
9A
BA
AA
18 AA
ii
dd
hh ll
ff
ff
2
3
4
4
5
Ñ Ñ Ñ Ñ ∆ ∆ 0 Ñ
ORAB
OR accumulator B (inclusive)
B+M⇒B
B
B
B
B
B
IMM
DIR
EXT
IND, X
IND, Y
CA
DA
FA
EA
18 EA
ii
dd
hh ll
ff
ff
2
3
4
4
5
Ñ Ñ Ñ Ñ ∆ ∆ 0 Ñ
PSHA
Push A onto stack
A ⇒ Stack; SP = SPÐ1
A
INH
PSHB
Push B onto stack
B ⇒ Stack; SP = SPÐ1
B
INH
36
Ñ
3
Ñ Ñ Ñ Ñ Ñ Ñ Ñ Ñ
37
Ñ
3
PSHX
Push IX onto stack (low Þrst)
IX ⇒ Stack; SP = SPÐ2
Ñ Ñ Ñ Ñ Ñ Ñ Ñ Ñ
INH
3C
Ñ
4
PSHY
Push IY onto stack (low Þrst)
IY ⇒ Stack; SP = SPÐ2
Ñ Ñ Ñ Ñ Ñ Ñ Ñ Ñ
INH
18 3C
Ñ
5
Ñ Ñ Ñ Ñ Ñ Ñ Ñ Ñ
3D
70
60
18 60
TPG
MOTOROLA
11-12
CPU CORE AND INSTRUCTION SET
MC68HC11PH8
220
Table 11-2 Instruction set (Sheet 5 of 6)
Addressing
mode
Instruction
Condition codes
Mnemonic
Operation
Description
PULA
Pull A from stack
SP = SP+1; Stack ⇒ A
A
INH
32
Ñ
4
Ñ Ñ Ñ Ñ Ñ Ñ Ñ Ñ
B
Opcode
Operand
Cycles
S X H
I
N Z V C
PULB
Pull B from stack
SP = SP+1; Stack ⇒ B
INH
33
Ñ
4
Ñ Ñ Ñ Ñ Ñ Ñ Ñ Ñ
PULX
Pull IX from stack (high Þrst)
SP = SP+2; Stack ⇒ IX
INH
38
Ñ
5
Ñ Ñ Ñ Ñ Ñ Ñ Ñ Ñ
PULY
Pull IY from stack (high Þrst)
SP = SP+2; Stack ⇒ IY
INH
18 38
Ñ
6
Ñ Ñ Ñ Ñ Ñ Ñ Ñ Ñ
ROL (opr)
Rotate left
EXT
IND, X
IND, Y
79
69
18 69
hh ll
ff
ff
6
6
7
Ñ Ñ Ñ Ñ ∆ ∆ ∆ ∆
ROLA
Rotate left A
Ñ Ñ Ñ Ñ ∆ ∆ ∆ ∆
ROLB
Rotate left B
ROR (opr)
Rotate right
RORA
Rotate right A
RORB
Rotate right B
RTI
Return from interrupt
RTS
Return from subroutine
C
b7
b0
A
INH
49
Ñ
2
B
INH
59
Ñ
2
Ñ Ñ Ñ Ñ ∆ ∆ ∆ ∆
hh ll
ff
ff
6
6
7
Ñ Ñ Ñ Ñ ∆ ∆ ∆ ∆
EXT
IND, X
IND, Y
C
76
66
18 66
A
INH
46
Ñ
2
Ñ Ñ Ñ Ñ ∆ ∆ ∆ ∆
B
INH
56
Ñ
2
Ñ Ñ Ñ Ñ ∆ ∆ ∆ ∆
see Figure 11-2
INH
3B
Ñ
12
∆ ↓ ∆ ∆ ∆ ∆ ∆ ∆
see Figure 11-2
INH
39
Ñ
5
Ñ Ñ Ñ Ñ Ñ Ñ Ñ Ñ
b7
b0
SBA
Subtract B from A
AÐB⇒A
Ñ
2
Ñ Ñ Ñ Ñ ∆ ∆ ∆ ∆
SBCA (opr)
Subtract with carry from A
AÐMÐC⇒A
A
A
A
A
A
IMM
DIR
EXT
IND, X
IND, Y
82
92
B2
A2
18 A2
ii
dd
hh ll
ff
ff
2
3
4
4
5
Ñ Ñ Ñ Ñ ∆ ∆ ∆ ∆
SBCB (opr)
Subtract with carry from B
BÐMÐC⇒B
B
B
B
B
B
IMM
DIR
EXT
IND, X
IND, Y
C2
D2
F2
E2
18 E2
ii
dd
hh ll
ff
ff
2
3
4
4
5
Ñ Ñ Ñ Ñ ∆ ∆ ∆ ∆
SEC
Set carry
1⇒C
INH
0D
Ñ
2
Ñ Ñ Ñ Ñ Ñ Ñ Ñ 1
SEI
Set interrupt mask
1⇒I
INH
0F
Ñ
2
Ñ Ñ Ñ 1 Ñ Ñ Ñ Ñ
SEV
Set overßow ßag
1⇒V
INH
0B
Ñ
2
Ñ Ñ Ñ Ñ Ñ Ñ 1 Ñ
STAA (opr)
Store accumulator A
A⇒M
A
A
A
A
DIR
EXT
IND, X
IND, Y
97
B7
A7
18 A7
dd
hh ll
ff
ff
3
4
4
5
Ñ Ñ Ñ Ñ ∆ ∆ 0 Ñ
STAB (opr)
Store accumulator B
B⇒M
B
B
B
B
DIR
EXT
IND, X
IND, Y
D7
F7
E7
18 E7
dd
hh ll
ff
ff
3
4
4
5
Ñ Ñ Ñ Ñ ∆ ∆ 0 Ñ
STD (opr)
Store accumulator D
A ⇒ M; B ⇒ M+1
DIR
EXT
IND, X
IND, Y
DD
FD
ED
18 ED
dd
hh ll
ff
ff
4
5
5
6
Ñ Ñ Ñ Ñ ∆ ∆ 0 Ñ
STOP
Stop internal clocks
Ñ
Ñ
2
Ñ Ñ Ñ Ñ Ñ Ñ Ñ Ñ
STS (opr)
Store stack pointer
SP ⇒ M:M+1
DIR
EXT
IND, X
IND, Y
9F
BF
AF
18 AF
dd
hh ll
ff
ff
4
5
5
6
Ñ Ñ Ñ Ñ ∆ ∆ 0 Ñ
STX (opr)
Store index register X
IX ⇒ M:M+1
DIR
EXT
IND, X
IND, Y
DF
FF
EF
CD EF
dd
hh ll
ff
ff
4
5
5
6
Ñ Ñ Ñ Ñ ∆ ∆ 0 Ñ
STY (opr)
Store index register Y
IY ⇒ M:M+1
DIR
EXT
IND, X
IND, Y
18
18
1A
18
dd
hh ll
ff
ff
5
6
6
6
Ñ Ñ Ñ Ñ ∆ ∆ 0 Ñ
INH
10
INH
CF
DF
FF
EF
EF
11
TPG
MC68HC11PH8
CPU CORE AND INSTRUCTION SET
MOTOROLA
11-13
221
Table 11-2 Instruction set (Sheet 6 of 6)
11
Instruction
Condition codes
Addressing
mode
Opcode
Operand
A
A
A
A
A
IMM
DIR
EXT
IND, X
IND, Y
80
90
B0
A0
18 A0
ii
dd
hh ll
ff
ff
2
3
4
4
5
Ñ Ñ Ñ Ñ ∆ ∆ ∆ ∆
B
B
B
B
B
IMM
DIR
EXT
IND, X
IND, Y
C0
D0
F0
E0
18 E0
ii
dd
hh ll
ff
ff
2
3
4
4
5
Ñ Ñ Ñ Ñ ∆ ∆ ∆ ∆
D Ð M:M+1 ⇒ D
IMM
DIR
EXT
IND, X
IND, Y
83
93
B3
A3
18 A3
jj kk
dd
hh ll
ff
ff
4
5
6
6
7
Ñ Ñ Ñ Ñ ∆ ∆ ∆ ∆
Software interrupt
see Figure 11-2
INH
3F
Ñ
14
Ñ Ñ Ñ 1 Ñ Ñ Ñ Ñ
Transfer A to B
A⇒B
INH
16
Ñ
2
Ñ Ñ Ñ Ñ ∆ ∆ 0 Ñ
TAP
Transfer A to CC register
A ⇒ CCR
INH
06
Ñ
2
∆ ↓ ∆ ∆ ∆ ∆ ∆ ∆
TBA
Transfer B to A
B⇒A
INH
17
Ñ
2
Ñ Ñ Ñ Ñ ∆ ∆ 0 Ñ
TEST
Test (only in test modes)
address bus increments
INH
00
Ñ
TPA
Transfer CC register to A
CCR ⇒ A
INH
07
Ñ
2
Ñ Ñ Ñ Ñ Ñ Ñ Ñ Ñ
TST (opr)
Test for zero or minus
MÐ0
hh ll
ff
ff
6
6
7
Ñ Ñ Ñ Ñ ∆ ∆ 0 0
Mnemonic
Operation
Description
SUBA (opr)
Subtract memory from A
AÐM⇒A
SUBB (opr)
Subtract memory from B
BÐM⇒B
SUBD (opr)
Subtract memory from D
SWI
TAB
EXT
IND, X
IND, Y
7D
6D
18 6D
Cycles
S X H
I
N Z V C
Ñ Ñ Ñ Ñ Ñ Ñ Ñ Ñ
TSTA
Test A for zero or minus
AÐ0
A
INH
4D
Ñ
2
Ñ Ñ Ñ Ñ ∆ ∆ 0 0
TSTB
Test B for zero or minus
BÐ0
B
INH
5D
Ñ
2
Ñ Ñ Ñ Ñ ∆ ∆ 0 0
TSX
Transfer stack pointer to X
SP + 1 ⇒ IX
INH
30
Ñ
3
Ñ Ñ Ñ Ñ Ñ Ñ Ñ Ñ
TSY
Transfer stack pointer to Y
SP + 1 ⇒ IY
INH
18 30
Ñ
4
Ñ Ñ Ñ Ñ Ñ Ñ Ñ Ñ
TXS
Transfer X to stack pointer
IX Ð 1 ⇒ SP
INH
35
Ñ
3
Ñ Ñ Ñ Ñ Ñ Ñ Ñ Ñ
TYS
Transfer Y to stack pointer
IY Ð 1 ⇒ SP
INH
18 35
Ñ
4
Ñ Ñ Ñ Ñ Ñ Ñ Ñ Ñ
WAI
Wait for interrupt
stack registers & WAIT
INH
3E
Ñ
à
Ñ Ñ Ñ Ñ Ñ Ñ Ñ Ñ
XGDX
Exchange D with X
IX ⇒ D; D ⇒ IX
INH
8F
Ñ
3
Ñ Ñ Ñ Ñ Ñ Ñ Ñ Ñ
XGDY
Exchange D with Y
IY ⇒ D; D ⇒ IY
INH
18 8F
Ñ
4
Ñ Ñ Ñ Ñ Ñ Ñ Ñ Ñ
Operators
⇒ Is transferred to
¥ Boolean AND
+ Arithmetic addition, except where used as an
inclusive-OR symbol in Boolean formulae
⊕ Exclusive-OR
* Multiply
: Concatenation
Ð Arithmetic subtraction, or negation symbol
(Twos complement)
Operands
dd 8-bit direct address ($0000Ð$00FF); the high byte is assumed
to be zero
ff 8-bit positive offset ($00 to $FF (0 to 256)) is added to the
contents of the index register
hh High order byte of 16-bit extended address
ii One byte of immediate data
jj High order byte of 16-bit immediate data
kk Low order byte of 16-bit immediate data
ll Low order byte of 16-bit extended address
mm 8-bit mask (set bits to be affected)
rr Signed relative offset ($80 to $7F (Ð128 to +127));
offset is relative to the address following the offset byte
Cycles
Condition Codes
Ñ Bit not changed
0 Bit always cleared
1 Bit always set
∆ Bit set or cleared, depending on the operation
↓ Bit can be cleared, but cannot become set
? Not deÞned
à
InÞnite, or until reset occurs
12 cycles are used, beginning with the opcode
fetch. A wait state is entered, which remains
in effect for an integer number of MPU E clock
cycles (n) until an interrupt is recognised.
Finally, two additional cycles are used to fetch
the appropriate interrupt vector. (14 + n, total).
TPG
MOTOROLA
11-14
CPU CORE AND INSTRUCTION SET
MC68HC11PH8
222
A
ELECTRICAL SPECIFICATIONS (STANDARD)
This section contains the electrical specifications and associated timing information for the
standard supply voltage (VDD = 5V ± 10%) MC68HC11PH8 variants.
1.1
Maximum ratings
Rating
Supply voltage (1)
Input voltage (1)
Operating temperature range
Ð MC68HC11PH8, MC68HC711PH8
Storage temperature range
Current drain per pin (2)
Ð not VDD, VSS, VDD AD, VSS AD, VRH or VRL
Symbol
VDD
Vin
TA
Unit
V
V
Tstg
Value
Ð 0.3 to +7.0
Ð 0.3 to +7.0
TL to TH
Ð40 to +85
Ð 55 to +150
ID
25
mA
°C
°C
(1) All voltages are with respect to VSS.
(2) Maximum current drain per pin is for one pin at a time, observing maximum power
dissipation limits.
Note:
1.2
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.
12
Thermal characteristics and power considerations
The average chip junction temperature, TJ, in degrees Celsius can be obtained from the following
equation:
TPG
MC68HC11PH8
ELECTRICAL SPECIFICATIONS (STANDARD)
MOTOROLA
A-1
223
T J = T A + ( P D • θ JA )
[1]
where:
TA = Ambient temperature (°C)
θJA = Package thermal resistance, junction-to-ambient (°C/W)
PD = Total power dissipation = 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:
K
P D = --------------------T J + 273
[2]
Solving equations [1] and [2] for K gives:
K = P D • ( T A + 273 ) + θ JA • P D2
[3]
where K is a constant for 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 below:
Characteristics
Thermal resistance
Ð 84-pin PLCC package
Ð 84-pin CERQUAD package (EPROM)
Ð 112-pin QFP package
Symbol
θJA
Value
Unit
°C/W
50
50
TBD
12
TPG
MOTOROLA
A-2
ELECTRICAL SPECIFICATIONS (STANDARD)
MC68HC11PH8
224
1.3
Test methods
Clocks,
strobes
~VDD
0.4V
0.4V
~VSS
VDD Ð 0.8V
nominal
nominal
70% of VDD
Inputs
20% of VDD
nominal timing
~VDD
VDD Ð 0.8V
0.4V
Outputs
~VSS
(b) DC testing
Clocks,
strobes
~VDD
20% of VDD
~VSS
20% of VDD
70% of VDD
spec.
Inputs
20% of VDD
spec.
70% of VDD
VDD Ð 0.8V (2)
0.4V (2)
spec. timing
~VDD
70% of VDD
20% of VDD
Outputs
~VSS
(c) AC testing
Notes:
(1) Full test loads are applied during all DC electrical tests and AC timing measurements.
(2) During AC timing measurements, inputs are driven to 0.4V and VDD Ð 0.8V;
timing measurements are taken at the 20% and 70% of VDD points.
Figure A-1 Test methods
12
TPG
MC68HC11PH8
ELECTRICAL SPECIFICATIONS (STANDARD)
MOTOROLA
A-3
225
1.4
DC electrical characteristics
(VDD = 5.0 Vdc ± 10%, VSS = 0 Vdc, TA = TL to TH, unless otherwise noted)
Characteristic
Symbol
Output voltage(1) (ILOAD = ± 10 µA):
All outputs except XTAL
VOL
All outputs except XTAL, RESET & MODA
VOH
Output high voltage(1) (ILOAD = Ð0.8mA, VDD =4.5V):
All outputs except XTAL, RESET & MODA
VOH
Output low voltage (ILOAD = +1.6mA):
All outputs except XTAL
VOL
Input high voltage:
VIH
All inputs except RESET
RESET
Input low voltage Ð all inputs
VIL
I/O ports three-state leakage (VIN = VIH or VIL)(2):
Ports A, B, C, D, F, G, H, MODA/LIR, RESET
IOZ
Input leakage(2) (VIN = VDD or VSS):
IIN
MODB/VSTBY
IRQ, XIRQ (ROM parts)
XIRQ (EPROM parts)
Input current with pull-up resistors (VIN = VIL):
Ports B, C, F, G, H
IIPR
RAM stand-by voltage (power down)
VSB
RAM stand-by current (power down)
ISB
CIN
Input capacitance:
Port E, IRQ, XIRQ, EXTAL
Ports A, B, C, D, F, G, H, MODA/LIR, RESET
Output load capacitance:
CL
All outputs except PD[4:1], PG[4:1], XTAL, MODA/LIR
PD[4:1], PG[4:1]
Min.
Max.
Unit
Ñ
VDD Ð 0.1
0.1
Ñ
V
V
VDD Ð 0.8
Ñ
V
Ñ
0.4
V
V
0.7VDD
0.8VDD
VSS Ð 0.3
VDD + 0.3
VDD + 0.3
0.2VDD
Ñ
±10
Ñ
Ñ
Ñ
±10
±1
±10
20
2.0
Ñ
100
VDD
10
Ñ
Ñ
8
12
Ñ
Ñ
90
200
V
µA
µA
µA
V
µA
pF
pF
(1) VOH speciÞcation for RESET and MODA is not applicable as they are open-drain pins.
VOH speciÞcation is not applicable to port C, port D and port G[5:0] in wired-OR mode.
(2) Refer to A/D speciÞcation for the leakage current value for port E.
12
TPG
MOTOROLA
A-4
ELECTRICAL SPECIFICATIONS (STANDARD)
MC68HC11PH8
226
A.4.1
DC electrical characteristics — modes of operation
(VDD = 5.0 Vdc ± 10%, VSS = 0 Vdc, TA = TL to TH, unless otherwise noted)
Characteristic
Maximum total supply current (including PLL)(1):
RUN: Single chip mode
RUN: Expanded mode
WAIT: Single chip mode(2)
STOP: Single chip mode
Maximum power dissipation: Single chip mode
Maximum power dissipation: Expanded mode
Symbol
IDD
PD
6kHz
TBD
TBD
500
50
TBD
TBD
2MHz 3MHz 4MHz
27
35
500
50
149
193
32
42
500
50
176
231
40
50
500
50
220
275
Unit
mA
mA
µA
µA
mW
mW
(1) All current measurements taken with suitable decoupling capacitors across the power supply to suppress
the transient switching currents inherent in CMOS designs.
EXTAL is driven with a square wave, with tCYC = 167ms for 6kHz devices; 500/333/250ns for 2/3/4MHz
devices.
VIL ≤ 0.2V; VIH ≥ VDD Ð 0.2V; no DC loads
WAIT: all peripheral functions shut down
STOP: all clocks stopped
(2) WAIT values in the 6 kHz column obtained by using an external clock of 32 kHz and the PLL low-power
WAIT mode (WEN = 1).
12
TPG
MC68HC11PH8
ELECTRICAL SPECIFICATIONS (STANDARD)
MOTOROLA
A-5
227
1.5
Control timing
(VDD = 5.0 Vdc ± 10%, VSS = 0 Vdc, TA = TL to TH)
Characteristic (1)
Symbol
Frequency of operation
E clock period
Crystal frequency
External oscillator frequency
Processor control set-up time (tPCSU = tCYC/4 + 50ns)
fOP
tCYC
fXTAL
4fOP
tPCSU
PWRSTL
(3)
Reset input pulse width (2)
2.0MHz
Min.
Max.
0
2.0
500
Ñ
Ñ
8.0
0
8.0
175
Ñ
3.0MHz
Min.
Max.
0
3.0
333
Ñ
Ñ
12.0
0
12.0
133
Ñ
4.0MHz
Min.
Max.
0
4.0
250
Ñ
Ñ
16.0
0
16.0
112
Ñ
Unit
MHz
ns
MHz
MHz
ns
PWRSTL
16
1
Ñ
Ñ
16
1
Ñ
Ñ
16
1
Ñ
Ñ
tCYC
tMPS
tMPH
2
10
Ñ
Ñ
2
10
Ñ
Ñ
2
10
Ñ
Ñ
tCYC
ns
Ñ
ns
Ñ
ns
4
200
tCYC
kHz
(4)
Mode programming set-up time
Mode programming hold time
Interrupt pulse width (IRQ edge sensitive mode)
Timer pulse width
(Input capture and pulse accumulator inputs)
WAIT recovery start-up time
Clock monitor reset
PWIRQ
PWTIM
tWRS
fCMON
tCYC
+20
tCYC
+20
Ñ
10
Ñ
Ñ
4
200
tCYC
+20
tCYC
+20
Ñ
10
Ñ
Ñ
4
200
tCYC
+20
tCYC
+20
Ñ
10
(1) All timing is given with respect to 20% and 70% of VDD, unless otherwise noted.
(2) Reset is recognized during the Þrst clock cycle it is held low. Internal circuitry then drives the pin low for eight clock cycles,
releases the pin and samples the pin level four cycles later to determine the source of the interrupt. (See Section 10.)
(3) To guarantee an external reset vector.
(4) This is the minimum input time; it can be pre-empted by an internal reset.
PA[3:0](1)
PWTIM
PA[3:0](2)
PA7(1), (3)
12
PA7(2), (3)
Notes
(1) Rising edge sensitive input.
(2) Falling edge sensitive input.
(3) Maximum pulse accumulator clocking rate is E clock frequency divided by two (E/2).
Figure A-2 Timer inputs
TPG
MOTOROLA
A-6
ELECTRICAL SPECIFICATIONS (STANDARD)
MC68HC11PH8
228
VDD
EXTAL
tPORDELAY (1)
E
tPCSU
PWRSTL
RESET
tMPS
tMPH
MODA,
MODB
FFFE FFFE FFFE FFFE FFFF
Address
New
PC
FFFE FFFE FFFE FFFE FFFE FFFF
New
PC
(1) tPORDELAY = 4064 tCYC (or 128 tCYC depending on mask option - MC68HC11PH8 only)
Figure A-3 Reset timing
E clock
tPCSU
IRQ(1)
IRQ(2), XIRQ
or internal
interrupt
PWIRQ
Address(3)
OA
Data(4)
OP
OA+1
ÐÐ
SP
PCL
SPÐ1 SPÐ2 SPÐ3
PCH
IYL
IYH
SPÐ4 SPÐ5 SPÐ6 SPÐ7 SPÐ8 SPÐ8
IXL
IXH
B
A
CCR
ÐÐ
VA
VA+1
New
PC
VH
VL
OP
12
R/W
Notes:
(1) Edge sensitive IRQ pin (IRQE = 1).
(2) Level sensitive IRQ pin (IRQE = 0).
(3) Where OA = Opcode address and VA = Vector address.
(4) Where OP = Opcode, VH = Vector (MSB) and VL = Vector (LSB).
Figure A-4 Interrupt timing
TPG
MC68HC11PH8
ELECTRICAL SPECIFICATIONS (STANDARD)
MOTOROLA
A-7
229
Internal
clocks
IRQ(1)
PWIRQ
IRQ(2)
or XIRQ
tSTOPDELAY(3)
E clock
Address(4)
SA(6)
SA+1
SA+1
Opcode
Resume program with instruction which follows the STOP instruction
Address(5)
Notes:
SA(6)
SA+1
SA+1
SA+2 SPÉ SPÐ7 SPÐ8 SPÐ8 FFF2 FFF3
New
PC
(1) Edge sensitive IRQ pin (IRQE = 1).
(2) Level sensitive IRQ pin (IRQE = 0).
(3) If DLY = 1: tSTOPDELAY = 4064 tCYC (or 128 tCYC depending on mask option - MC68HC11PH8 only)
If DLY = 0: tSTOPDELAY = 4 tCYC
(4) XIRQ with X-bit in CCR = 1.
(5) IRQ (or XIRQ, with X-bit = 0; in this case vector fetch will be $FFF4/5).
(6) SA = STOP address.
Figure A-5 STOP recovery timing
E clock
tPCSU
IRQ, XIRQ,
or internal
interrupts
tWRS
Address
12
WA(1) WA+1
SP
SPÐ1
SPÐ2ÉSPÐ8
SPÐ8
SPÐ8ÉSPÐ8
SPÐ8 SPÐ8 SPÐ8
VA(2)
VA+1
New
PC
Stack registers
R/W
Notes:
RESET also causes recovery from WAIT.
(1) WA = WAIT address.
(2) VA = Vector address.
Figure A-6 WAIT recovery timing
TPG
MOTOROLA
A-8
ELECTRICAL SPECIFICATIONS (STANDARD)
MC68HC11PH8
230
A.5.1
Peripheral port timing
(VDD = 5.0 Vdc ± 10%, VSS = 0 Vdc, TA = TL to TH)
Characteristic (1)
Symbol
Frequency of operation (E clock frequency)
E clock period
Peripheral data set-up time, all ports (2)
Peripheral data hold time, all ports (2)
Delay time, peripheral data write
MCU write to port A, B, G or H
MCU write to port C, D or F (tPWD = tCYC/4 + 100ns)
fOP
tCYC
tPDSU
tPDH
tPWD
2.0MHz
Min.
Max.
0
2.0
500
Ñ
100
Ñ
50
Ñ
Ñ
Ñ
200
225
3.0MHz
Min.
Max.
0
3.0
333
Ñ
100
Ñ
50
Ñ
Ñ
Ñ
200
183
4.0MHz
Min. Max.
0
4.0
250
Ñ
100
Ñ
50
Ñ
Ñ
Ñ
Unit
MHz
ns
ns
ns
ns
200
162
(1) All timing is given with respect to 20% and 70% of VDD, unless otherwise noted.
(2) Port C, D and G timing is valid for active drive (CWOM, DWOM, GWOM, WOMS and WOMS2 bits clear).
MCU read of port
E clock
tPDSU
tPDH
Ports
A, C, D, F
tPDSU
tPDH
Ports
B, E, G, H
Figure A-7 Port read timing diagram
MCU write to port
E clock
tPWD
Ports
C, D, F
Previous port data
New data valid
tPWD
Ports
A, B, G, H
Previous port data
12
New data valid
Figure A-8 Port write timing diagram
TPG
MC68HC11PH8
ELECTRICAL SPECIFICATIONS (STANDARD)
MOTOROLA
A-9
231
A.5.2
PLL control timing
(VDD = 5.0Vdc ±10%, VSS = 0Vdc, TA = TL to TH unless otherwise noted)
Characteristic
PLL reference frequency
System frequency
PLL output frequency
External clock operation
Capacitor on pin XFC
PLL stabilization time(2)
4XCLK stability(3)(4)
Short term
Long term
Symbol
fREF
fSYS
fVCOOUT
fXTAL
CXFC
tPLLS
CSTAB
Mask option 1
Min Typical Maximum
25
32
50
dc
Ñ
4
0.05
Ñ
16
dc
16
Ñ
47
Ñ
Ñ
20
TBD
Min
50
dc
0.1
dc
Ñ
Ñ
TBD
TBD
TBD
TBD
Ñ
Ñ
TBD
TBD
Mask option 2(1)
Typical Maximum
614
2000
Ñ
4
Ñ
16
16
47
Ñ
10
TBD
Ñ
Ñ
TBD
TBD
Units
kHz
MHz
nF
ms
%
(1) This mask option does not exist on the MC68HC711PH8, on which the PLL is optimized for use at 32kHz.
(2) Assumes that stable VDDSYN is applied, that an external Þlter capacitor with a value of 47nF is attached to the XFC pin,
and that the crystal oscillator is stable. Stabilization time is measured from power-up to RESET release. This speciÞcation
also applies to the period required for PLL stabilization after changing the X and Y frequency control bits in the
synthesizer control register (SYNR) while PLL is running, and to the period required for the clock to stabilize after WAIT
with WEN = 1.
(3) Short term stability is the average deviation from programmed frequency measured over a 2µs interval at maximum fSYS,
Long term 4XCLK stability is the average deviation from programmed frequency measured over a 1ms interval at
maximum fSYS. Stability is measured with a stable external clock applied Ñ variation in crystal oscillator frequency is
additive to this Þgure.
(4) This parameter is periodically sampled rather than 100% tested.
12
TPG
MOTOROLA
A-10
ELECTRICAL SPECIFICATIONS (STANDARD)
MC68HC11PH8
232
A.5.3
Analog-to-digital converter characteristics
(VDD = 5.0 Vdc ± 10%, VSS = 0 Vdc, TA = TL to TH, 750kHz ≤ E ≤ 4MHz, unless otherwise noted)
Characteristic
Parameter
Min.
Resolution
Number of bits resolved by ADC
Ñ
Maximum deviation from the ideal ADC transfer
Non-linearity
Ñ
characteristics
Difference from the output of an ideal ADC for zero
Zero error
Ñ
input voltage
Difference from the output of an ideal ADC for
Full-scale error
Ñ
full-scale input voltage
Total unadjusted
Maximum sum of non-linearity, zero and full-scale
Ñ
error
errors
Quantization error Uncertainty due to converter resolution
Ñ
Difference between the actual input voltage and the
Absolute accuracy full-scale weighted equivalent of the binary output
Ñ
code, including all error sources
Conversion range Analog input voltage range
VRL
VRH
Analog reference voltage (high) (2)
VRL
VRL
Analog reference voltage (low) (2)
VSSÐ0.1
∆VR
Minimum difference between VRH and VRL (2)
3
Conversion time
Total time to perform a single A/D conversion:
E clock
Internal RC oscillator
Conversion result never decreases with an increase
in input voltage and has no missing codes
Zero input reading Conversion result when VIN = VRL
Full-scale reading Conversion result when VIN = VRH
Ñ
Ñ
Absolute
8
2MHz(1) 3MHz(1) 4MHz(1)
Unit
Max.
Max.
Max.
Ñ
Ñ
Ñ
bits
Ñ
±0.5
±1
±1
LSB
Ñ
±0.5
±1
±1
LSB
Ñ
±0.5
±1
±1
LSB
Ñ
±0.5
±1.5
±1.5
LSB
Ñ
±0.5
±0.5
±0.5
LSB
Ñ
±1
±2
±2
LSB
Ñ
Ñ
Ñ
Ñ
VRH
VRH
VRH
VDD+0.1 VDD+0.1 VDD+0.1
VRH
VRH
VRH
Ñ
Ñ
Ñ
32
Ñ
Ñ
Ñ
Ñ
tCYC+32 tCYC+32 tCYC+32
Monotonicity
V
V
V
V
tCY
C
µs
Guaranteed
$00
Ñ
Ñ
Ñ
Ñ
$FF
Ñ
$FF
Ñ
$FF
Analog input acquisition sampling time:
E clock
Internal RC oscillator
Ñ
Ñ
12
Ñ
Ñ
12
Ñ
12
Ñ
12
Sample/hold
capacitance
Input capacitance (PE[0:7]) during sample
Ñ
20 (typ)
Ñ
Ñ
Ñ
pF
Input leakage
Input leakage on A/D pins:
PE[0:7]
VRL, VRH
Ñ
Ñ
Ñ
Ñ
400
1.0
400
1.0
400
1.0
nA
µA
Sample acquisition
time
Hex
Hex
tCY
C
µs
12
(1) For fOP < 2MHz, source impedances should be approximately 10kΩ. For fOP ≥ 2MHz, source impedances should be in the
range 5Ð10kΩ. Source impedances greater than 10kΩ have an adverse affect on A/D accuracy, because of input leakage.
(2) Performance veriÞed down to ∆VR = 2.5V, however accuracy is tested and guaranteed at ∆VR = 5V ± 10%.
TPG
MC68HC11PH8
ELECTRICAL SPECIFICATIONS (STANDARD)
MOTOROLA
A-11
233
A.5.4
Serial peripheral interface timing
(VDD = 5.0 Vdc ± 10%, VSS = 0 Vdc, TA = TL to TH)
Characteristic (1)
Num
Operating frequency
Symbol
Master
Slave
Master
Slave
Master
Slave
Master
Slave
Master
Slave
Master
Slave
Master
Slave
Master
Slave
Slave
Slave
1
Cycle time
2
Enable lead time (2)
3
Enable lag time (2)
4
Clock (SCK) high time
5
Clock (SCK) low time
6
Input data set-up time
7
Input data hold time
8
9
10
11
12
Access time (from high-z to data active)
Disable time (hold time to high-z state)
Data valid (after enable edge) (3)
Output data hold time (after enable edge)
Rise time (3)
SPI outputs (SCK, MOSI and MISO)
SPI inputs (SCK, MOSI, MISO and SS)
Fall time (3)
SPI outputs (SCK, MOSI and MISO)
SPI inputs (SCK, MOSI, MISO and SS)
13
fOP(M)
fOP(S)
tCYC(M)
tCYC(S)
tLEAD(M)
tLEAD(S)
tLAG(M)
tLAG(S)
tW(SCKH)M
tW(SCKH)S
tW(SCKL)M
tW(SCKL)S
tSU(M)
tSU(S)
tH(M)
tH(S)
tA
tDIS
tV(S)
tHO
2.0MHz
Min. Max.
0
0.5
0
2.0
2.0
Ñ
500
Ñ
Ñ
Ñ
250
Ñ
Ñ
Ñ
250
Ñ
340
Ñ
190
Ñ
340
Ñ
190
Ñ
100
Ñ
100
Ñ
100
Ñ
100
Ñ
0
120
Ñ
300
Ñ
240
0
Ñ
3.0MHz
Min. Max.
0
0.5
0
3.0
2.0
Ñ
333
Ñ
Ñ
Ñ
240
Ñ
Ñ
Ñ
240
Ñ
227
Ñ
127
Ñ
227
Ñ
127
Ñ
100
Ñ
100
Ñ
100
Ñ
100
Ñ
0
120
Ñ
300
Ñ
167
0
Ñ
4.0MHz
Min. Max.
0
0.5
0
4.0
2.0
Ñ
250
Ñ
Ñ
Ñ
200
Ñ
Ñ
Ñ
200
Ñ
130
Ñ
85
Ñ
130
Ñ
85
Ñ
100
Ñ
100
Ñ
100
Ñ
100
Ñ
0
120
Ñ
300
Ñ
125
0
Ñ
Unit
fOP
MHz
tCYC
ns
ns
ns
ns
ns
ns
ns
ns
ns
ns
ns
tRM
tRS
Ñ
Ñ
100
2.0
Ñ
Ñ
100
2.0
Ñ
Ñ
100
2.0
ns
µs
tFM
tFS
Ñ
Ñ
100
2.0
Ñ
Ñ
100
2.0
Ñ
Ñ
100
2.0
ns
µs
(1) All timing is given with respect to 20% and 70% of VDD, unless otherwise noted.
(2) Signal production depends on software.
(3) Assumes 200pF load on all SPI pins.
12
TPG
MOTOROLA
A-12
ELECTRICAL SPECIFICATIONS (STANDARD)
MC68HC11PH8
234
SS
(input)
SS is held high on master
1
SCK (CPOL=0)
(output)
SCK (CPOL=1)
(output)
12
13
13
12
5
(see note)
4
5
(see note)
4
6
MISO
(input)
7
MSB in
Bit 6ÉÉ1
11
10 (ref.)
MOSI
(output)
Master MSB out
LSB in
10
11 (ref.)
Bit 6ÉÉ1
Master LSB out
13
12
Note: This Þrst clock edge is generated internally, but is not seen at the SCK pin.
Figure A-9 SPI master timing (CPHA = 0)
SS
(input)
SS is held high on master
1
13
12
5
SCK (CPOL=0)
(output)
(see note)
4
12
13
5
SCK (CPOL=1)
(output)
(see note)
4
6
MISO
(input)
MSB in
10 (ref.)
Bit 6ÉÉ1
11
MOSI
(output)
Master MSB out
7
LSB in
10
Bit 6ÉÉ1
13
11 (ref.)
Master LSB out
12
Note: This last clock edge is generated internally, but is not seen at the SCK pin.
12
Figure A-10 SPI master timing (CPHA = 1)
TPG
MC68HC11PH8
ELECTRICAL SPECIFICATIONS (STANDARD)
MOTOROLA
A-13
235
SS
(input)
1
13
12
12
13
3
5
SCK (CPOL=0)
(input)
4
2
5
SCK (CPOL=1)
(input)
4
6
MOSI
(input)
7
MSB in
Bit 6ÉÉ1
8
MISO
(output)
10
Slave MSB out
LSB in
11
9
Bit 6ÉÉ1
Slave LSB out
(see note)
Note: Not deÞned, but normally the MSB of character just received.
Figure A-11 SPI slave timing (CPHA = 0)
SS
(input)
1
SCK (CPOL=0)
(input)
12
12
13
3
4
2
5
SCK (CPOL=1)
(input)
4
6
MOSI
(input)
7
MSB in
8
MISO
(output)
13
5
Bit 6ÉÉ1
10
(see note)
LSB in
11
Slave MSB out
Bit 6ÉÉ1
9
Slave LSB out
Note: Not deÞned, but normally the LSB of character last transmitted.
12
Figure A-12 SPI slave timing (CPHA = 1)
TPG
MOTOROLA
A-14
ELECTRICAL SPECIFICATIONS (STANDARD)
MC68HC11PH8
236
A.5.5
Non-multiplexed expansion bus timing
(VDD = 5.0 Vdc ± 10%, VSS = 0 Vdc, TA = TL to TH)
Num
Characteristic (1)
Symbol
1
2
3
4A
4B
9
11
12
17
18
19
21
29
39
57
Frequency of operation (E clock frequency)
E clock period
Pulse width, E low (2), (3)
Pulse width, E high (2), (3)
E clock
rise time
fall time
Address hold time (3)
Address delay time (3)
Address valid to E rise time (3)
Read data set-up time
Read data hold time
Write data delay time
Write data hold time (3)
MPU address access time (3)
Write data set-up time (3)
Address valid to data three-state time
fOP
tCYC
PWEL
PWEH
tr
tf
tAH
tAD
tAV
tDSR
tDHR
tDDW
tDHW
tACCA
tDSW
tAVDZ
2.0MHz
Min. Max.
0
2.0
500
Ñ
230
Ñ
225
Ñ
Ñ
20
Ñ
20
53
Ñ
Ñ
103
127
Ñ
30
Ñ
0
Ñ
Ñ
40
63
Ñ
348
Ñ
185
Ñ
Ñ
10
3.0MHz
Min. Max.
0
3.0
333
Ñ
147
Ñ
142
Ñ
Ñ
20
Ñ
18
32
Ñ
Ñ
82
65
Ñ
30
Ñ
0
Ñ
Ñ
40
42
Ñ
203
Ñ
102
Ñ
Ñ
10
4.0MHz
Min. Max.
0
4.0
250
Ñ
105
Ñ
100
Ñ
Ñ
20
Ñ
15
21
Ñ
Ñ
71
34
Ñ
20
Ñ
0
Ñ
Ñ
40
31
Ñ
144
Ñ
60
Ñ
Ñ
10
Unit
MHz
ns
ns
ns
ns
ns
ns
ns
ns
ns
ns
ns
ns
ns
ns
(1) All timing is given with respect to 20% and 70% of VDD, unless otherwise noted.
(2) Input clock duty cycles other than 50% will affect the bus performance.
(3) For fOP ≤ 2MHz the following formulae may be used to calculate parameter values:
PWEL = tCYC/2 Ð 20ns
PWEH = tCYC/2 Ð 25ns
tAH = tCYC/8 Ð 10ns
tAD = tCYC/8 + 40ns
tAV = PWEL Ð tAD
tDHW = tCYC/8
tACCA = tCYC Ð tf Ð tDSR Ð tAD
tDSW = PWEH Ð tDDW
12
TPG
MC68HC11PH8
ELECTRICAL SPECIFICATIONS (STANDARD)
MOTOROLA
A-15
237
1
3
4B
2
E clock
4A
11
12
9
R/W,
Address
29
17
18
Data
(read)
57
19
39
21
Data
(write)
Figure A-13 Expansion bus timing
A.5.6
EEPROM characteristics
Characteristic
Temperature range
Ð40 to +85°C
Unit
(1)
Programming time, tEEPROG
<1MHz, RCO enabled
1Ð2MHz, RCO disabled
≥2MHz & whenever RCO enabled
Erase time: byte, row and bulk (1)
Write/erase endurance (2)
Data retention (2)
10
20
10
10
10000
10
ms
ms
cycles
years
(1) The RC oscillator (RCO) must be enabled (by setting the CSEL bit in the OPTION
register) for EEPROM programming and erasure when the E clock frequency is less
than 1.0MHz.
(2) Refer to the current issue of MotorolaÕs quarterly Reliability Monitor Report for the
latest failure rate information.
12
EPROM characteristics
A.5.7
(VDD = 5.0 Vdc ± 10%, VSS = 0 Vdc, TA = TL to TH, unless otherwise noted)
Characteristic
Symbol
Min
Programming voltage
VPPE
12
Programming voltage detect level
VPPH
TBD
Programming time
tEPROG
—
Max
12.75
TBD
5
Unit
V
V
ms
TPG
MOTOROLA
A-16
ELECTRICAL SPECIFICATIONS (STANDARD)
MC68HC11PH8
238
B
MECHANICAL DATA AND ORDERING
INFORMATION
B.1
Pin assignments
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
74
73
72
71
70
69
68
67
66
65
64
63
62
61
60
59
58
57
56
55
54
PD2/MISO
PD1/TXD1
PD0/RXD1
MODA/LIR
RESET
XFC
VDDSYN
EXTAL
XTAL
E
VDDR
VSSR
PC7/D7
PC6/D6
PC5/D5
PC4/D4
PC3/D3
PC2/D2
PC1/D1
PC0/D0
IRQ
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
PW1/PH0
PW2/PH1
PW3/PH2
PW4/PH3
PH4
PH5
PH6
PH7
MODB/VSTBY
VPPE/XIRQ
VDD
VDDL
VSSL
VSS
R/W/PG7
LCDBP/PG6
SS2/PG5
SCK2/PG4
MOSI2/PG3
MISO2/PG2
TXD2/PG1
84
83
82
81
80
79
78
77
76
75
11
10
9
8
7
6
5
4
3
2
PB0/A8
PB1/A9
PB2/A10
PB3/A11
PB4/A12/LCD4
PB5/A13/LCD5
PB6/A14/LCD6
PB7/A15/LCD7
VSS
VDD
PA0/IC3
PA1/IC2
PA2/IC1
PA3/OC1/OC5/IC4
PA4/OC1/OC4
PA5/OC1/OC3
PA6/OC1/OC2
PA7/OC1/PAI
PD5/SS
PD4/SCK
PD3/MOSI
The MC68HC11PH8 is available in 84-pin PLCC or 112-pin TQFP packages; in addition to those
two packages, the MC68HC711PH8 is available in a windowed 84-pin CERQUAD package, to
allow full use of the EPROM.
RXD2/PG0
VDD AD
AD7/PE7
AD6/PE6
AD5/PE5
AD4/PE4
AD3/PE3
AD2/PE2
AD1/PE1
AD0/PE0
VRL
VRH
VSS AD
A7/PF7
A6/PF6
A5/PF5
A4/PF4
A3/PF3
A2/PF2
A1/PF1
A0/PF0
13
Figure B-1 84-pin PLCC/CERQUAD pinout
TPG
MC68HC11PH8
MECHANICAL DATA AND ORDERING INFORMATION
MOTOROLA
B-1
239
NC
NC
PB0/A8
PB1/A9
PB2/A10
PB3/A11
PB4/A12/LCD4
PB5/A13/LCD5
PB6/A14/LCD6
PB7/A15/LCD7
VSS
VDD
PA0/IC3
NC
NC
PA1/IC2
PA2/IC1
PA3/OC1/OC5/IC4
PA4/OC1/OC4
PA5/OC1/OC3
NC
PA6/OC1/OC2
PA7/OC1/PAI
PD5/SS
PD4/SCK
PD3/MOSI
NC
NC
111
110
109
108
107
106
105
104
103
102
101
100
99
98
97
96
95
94
93
92
91
90
89
88
87
86
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
84
83
82
81
80
79
78
77
76
75
74
73
72
71
70
69
68
67
66
65
64
63
62
61
60
59
58
57
NC
PD2/MISO
PD1/TXD
PD0RXD
MODA/LIR
RESET
XFC
VDDSYN
NC
NC
NC
EXTAL
XTAL
E
4XOUT
VDDR
VSSR
PC7/D7
PC6/D6
PC5/D5
PC4/D4
PC3/D3
PC2/D2
PC1/D1
PC0/D0
IRQ
NC
NC
NC
RXD2/PG0
NC
VDDAD
AD7/PE7
AD6/PE6
AD5/PE5
AD4/PE4
AD3/PE3
AD2/PE2
AD1/PE1
AD0/PE0
VRL
NC
NC
VRH
VSSAD
NC
A7/PF7
A6/PF6
A5/PF5
A4/PF4
A3/PF3
A2/PF2
A1/PF1
A0/PF0
NC
NC
NC
NC
PW1/PH0
PW2/PH1
PW3/PH2
PW4/PH3
PH4
PH5
PH6
PH7
NC
MODB/VSTBY
VPPE/XIRQ
NC
VDDL
VSSL
NC
NC
R/W/PG7
LCDBP/PG6
SS2/PG5
SCK2/PG4
MOSI2/PG3
MISO2/PG2
TXD2/PG1
NC
NC
NC
Figure B-2 112-pin TQFP pinout
13
TPG
MOTOROLA
B-2
MECHANICAL DATA AND ORDERING INFORMATION
MC68HC11PH8
240
B.2
Package dimensions
0.18 M T N S ÐP S
ÐNÐ
B
L S ÐM S
Y brk
ÐLÐ
ÐMÐ
Case No. 780-01
84 lead PLCC
G1
W
pin 84
(Note 1)
Z1
pin 1
ÐPÐ
X
V
U
0.18 M T N S ÐP S
A
R
L S ÐM S
0.18 M T L S ÐM S N S ÐP S
0.18 M T L S ÐM S N S ÐP S
Z
0.18 M T L S ÐM S N S ÐP S
0.18 M T N S ÐP S
C
L S ÐM S
H
0.10
G
G1
J E
K1
ÐTÐ Seating plane
K
0.25 S T L S ÐM S N S ÐP S
0.18 M T L S ÐM S N S ÐP S
0.18 M T N S ÐP S
Dim.
A
B
C
E
F
G
H
J
K
R
Min.
Max.
30.10
30.35
30.10
30.35
4.20
4.57
2.29
2.79
0.33
0.48
1.27 BSC
0.66
0.81
0.51
Ñ
0.64
Ñ
29.21
29.36
Notes
1. Due to space limitations, this case shall be represented by a
general case outline, rather than one showing all the leads.
2. Datums ÐLÐ, ÐMÐ, ÐNÐ and ÐPÐ are determined where top of lead
shoulder exits plastic body at mould parting line.
3. Dimension G1, true position to be measured at datum ÐTÐ (seating
plane).
4. Dimensions R and U do not include mould protrusion. Allowable
mould protrusion is 0.25mm per side.
5. Dimensions and tolerancing per ANSI Y 14.5M, 1982.
6. All dimensions in mm.
F
L S ÐM S
Dim.
U
V
W
X
Y
Z
G1
K1
Z1
Min.
29.21
1.07
1.07
1.07
Ñ
2°
28.20
1.02
2°
Max.
29.36
1.21
1.21
1.42
0.50
10°
28.70
Ñ
10°
13
Figure B-3 84-pin PLCC mechanical dimensions
TPG
MC68HC11PH8
MECHANICAL DATA AND ORDERING INFORMATION
MOTOROLA
B-3
241
0.18 M T N S ÐP S
ÐNÐ
B
L S ÐM S
Y brk
ÐLÐ
ÐMÐ
Case No. 780A-01
84 lead CERQUAD
G1
W
pin 84
(Note 1)
Z1
pin 1
ÐPÐ
X
V
U
0.18 M T N S ÐP S
A
R
L S ÐM S
0.18 M T L S ÐM S N S ÐP S
0.18 M T L S ÐM S N S ÐP S
Z
0.18 M T L S ÐM S N S ÐP S
0.18 M T N S ÐP S
C
L S ÐM S
H
0.10
G
G1
J E
K1
ÐTÐ Seating plane
K
0.25 S T L S ÐM S N S ÐP S
0.18 M T L S ÐM S N S ÐP S
0.18 M T N S ÐP S
13
Dim.
A
B
C
E
F
G
H
J
K
R
Min.
Max.
30.10
30.35
30.10
30.35
4.20
4.57
2.29
2.79
0.33
0.53
1.27 BSC
0.66
0.81
0.51
Ñ
0.64
Ñ
29.21
29.36
Notes
1. Due to space limitations, this case shall be represented by a
general case outline, rather than one showing all the leads.
2. Datums ÐLÐ, ÐMÐ, ÐNÐ and ÐPÐ are determined where top of lead
shoulder exits package body at glass parting line.
3. Dimension G1, true position to be measured at datum ÐTÐ (seating
plane).
4. Dimensions R and U do not include glass protrusion. Allowable
glass protrusion is 0.25mm per side.
5. Dimensions and tolerancing per ANSI Y 14.5M, 1982.
6. All dimensions in mm.
F
L S ÐM S
Dim.
U
V
W
X
Y
Z
G1
K1
Z1
Min.
29.21
1.07
1.07
1.07
Ñ
2°
28.20
1.02
2°
Max.
29.36
1.21
1.21
1.42
0.50
10°
28.70
Ñ
10°
Figure B-4 84-pin CERQUAD mechanical dimensions
TPG
MOTOROLA
B-4
MECHANICAL DATA AND ORDERING INFORMATION
MC68HC11PH8
242
Please contact your Motorola Sales Office
for up-to-date information on the mechanical
dimensions for this package type.
13
Figure B-5 112-pin TQFP mechanical dimensions
TPG
MC68HC11PH8
MECHANICAL DATA AND ORDERING INFORMATION
MOTOROLA
B-5
243
B.3
Ordering Information
Use the information in Table B-1 to specify the appropriate device type when placing an order.
Table B-1 Ordering information
Package
84-pin
PLCC
112-pin
TQFP
84-pin
CERQUAD
Temperature
Description
Frequency
3MHz
Custom ROM
4MHz
3MHz
Ð40 to +85°C Custom ROM, with security feature
4MHz
3MHz
OTPROM (with security feature)
4MHz
3MHz
Custom ROM
4MHz
3MHz
Ð40 to +85°C Custom ROM, with security feature
4MHz
3MHz
OTPROM (with security feature)
4MHz
3MHz
Ð40 to +85°C
EPROM (with security feature)
4MHz
MC order number
MC68HC11PH8CFN3
MC68HC11PH8CFN4
MC68S11PH8CFN3
MC68S11PH8CFN4
MC68S711PH8CFN3
MC68S711PH8CFN4
MC68HC11PH8CPV3
MC68HC11PH8CPV4
MC68S11PH8CPV3
MC68S11PH8CPV4
MC68S711PH8CPV3
MC68S711PH8CPV4
MC68S711PH8CFS3
MC68S711PH8CFS4
13
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MOTOROLA
B-6
MECHANICAL DATA AND ORDERING INFORMATION
MC68HC11PH8
244
C
DEVELOPMENT SUPPORT
The following information provides a reference to development tools for the M68HC11 family of
microcontrollers. For more detailed information please refer to the appropriate system manual.
Table C-1 M68HC11 development tools
Devices
MC68HC11PH8,
MC68HC711PH8
Note:
Evaluation
boards
Evaluation
modules
Evaluation systems/kits
Programmer boards
Ñ
M68EM11PH8
Ñ
M68SPGMR11
Target cables for the evaluation module should be ordered separately.
C.1
EVS — Evaluation system
The EVS is an economical tool for designing, debugging and evaluating target systems based on
the MC68HC11PH8 and MC68HC711PH8 device types. The two printed circuit boards that
comprise the EVS are the M68EM11PH8 emulator module and the M68PFB11KIT platform board.
The main features of the EVS are as follows:
•
Monitor/debugger firmware
•
Single-line assembler/disassembler
•
Host computer download capability
•
Dual memory maps:
–
64Kbyte monitor map that includes 16Kbytes of monitor EPROM
–
MC68HC711PH8 user map that includes 64Kbytes of emulation RAM
•
MCU extension I/O port for single chip, expanded and special test operating modes
•
RS-232C terminal and host I/O ports
•
Logic analyser connector
14
TPG
MC68HC11PH8
DEVELOPMENT SUPPORT
MOTOROLA
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245
C.2
MMDS11 — Motorola modular development system
The MMDS11 is an emulator system that provides a bus state analyser and real-time memory
windows. The unit’s integrated design environment includes an editor, an assembler, user
interface and source-level debug. A complete MMDS11 consists of:
•
A station module — the metal MMDS11 enclosure, containing the control board and the
internal power supply. Most system cables connect to the MMDS11 station module. (The cable
to an optional target system, however, runs through an aperture in the station module
enclosure to connect directly to the emulator module).
•
An emulator module (EM) — such as the EM11PH8: a printed circuit board that enables
system functionality for a specific set of MCUs. The EM fits into the station module through a
sliding panel in the enclosure top. The EM has a connector for the target cable.
•
Two logic clip cable assemblies — twisted pair cables that connect the station module to your
target system, a test fixture, a clock or any other circuitry useful for evaluation or analysis. One
end of each cable assembly has a moulded connector, which fits into station module pod A or
pod B. Leads at the other end of the cable terminate in female probe tips. Ball clips come with
the cables.
•
A 9-lead RS-232 serial cable — the cable that connects the station module to the host
computer’s RS-232 port.
C.3
SPGMR11 — Serial programmer system
The SPGMR11 is an economical tool for programming M68HC11 MCUs. The system consists of
the M68SPGMR11 unit and a programming module which adapts the SPGMR11 to the
appropriate MCU and package type. The programming module can be ordered as
M68PA11PH8FN84 (for the 84-pin package) and M68PA11PH8PV112 (for the 112-pin package).
14
TPG
MC68HC11PH8
DEVELOPMENT SUPPORT
MOTOROLA
C-2
246
GLOSSARY
This section contains abbreviations and specialist words used in this data
sheet and throughout the industry. Further information on many of the terms
may be gleaned from Motorola’s M68HC11 Reference Manual,
M68HC11RM/AD, or from a variety of standard electronics text books.
$xxxx
The digits following the ‘$’ are in hexadecimal format.
%xxxx
The digits following the ‘%’ are in binary format.
A/D, ADC
Analog-to-digital (converter).
Bootstrap mode
In this mode the device automatically loads its internal memory from an external
source on reset and then allows this program to be executed.
Byte
Eight bits.
CCR
Condition codes register; an integral part of the CPU.
CERQUAD
A ceramic package type, principally used for EPROM and high temperature devices.
Clear
‘0’ — the logic zero state; the opposite of ‘set’.
CMOS
Complementary metal oxide semiconductor. A semiconductor technology chosen for
its low power consumption and good noise immunity.
COP
Computer operating properly. aka ‘watchdog’. This circuit is used to detect device
runaway and provide a means for restoring correct operation.
CPU
Central processing unit.
D/A, DAC
Digital-to-analog (converter).
EEPROM
Electrically erasable programmable read only memory. aka ‘EEROM’.
EPROM
Erasable programmable read only memory. This type of memory requires exposure
to ultra-violet wavelengths in order to erase previous data. aka ‘PROM’.
ESD
Electrostatic discharge.
Expanded mode
In this mode the internal address and data bus lines are connected to external pins.
This enables the device to be used in much more complex systems, where there is a
need for external memory for example.
EVS
Evaluation system. One of the range of platforms provided by Motorola for evaluation
and emulation of their devices.
TPG
MC68HC11PH8
GLOSSARY
MOTOROLA
i
247
HCMOS
High-density complementary metal oxide semiconductor. A semiconductor
technology chosen for its low power consumption and good noise immunity.
I/O
Input/output; used to describe a bidirectional pin or function.
Input capture
(IC) This is a function provided by the timing system, whereby an external event is
‘captured’ by storing the value of a counter at the instant the event is detected.
Interrupt
This refers to an asynchronous external event and the handling of it by the MCU. The
external event is detected by the MCU and causes a predetermined action to occur.
IRQ
Interrupt request. The overline indicates that this is an active-low signal format.
K byte
A kilo-byte (of memory); 1024 bytes.
LCD
Liquid crystal display.
LSB
Least significant byte.
M68HC11
Motorola’s family of advanced 8-bit MCUs.
MCU
Microcontroller unit.
MI BUS
Motorola interconnect bus. A single wire, medium speed serial communications
protocol.
MSB
Most significant byte.
Nibble
Half a byte; four bits.
NRZ
Non-return to zero.
Opcode
The opcode is a byte which identifies the particular instruction and operating mode to
the CPU. See also: prebyte, operand.
Operand
The operand is a byte containing information the CPU needs to execute a particular
instruction. There may be from 0 to 3 operands associated with an opcode. See also:
opcode, prebyte.
Output compare
(OC) This is a function provided by the timing system, whereby an external event is
generated when an internal counter value matches a predefined value.
PLCC
Plastic leaded chip carrier package.
PLL
Phase-locked loop circuit. This provides a method of frequency multiplication, to
enable the use of a low frequency crystal in a high frequency circuit.
Prebyte
This byte is sometimes required to qualify an opcode, in order to fully specify a
particular instruction. See also: opcode, operand.
Pull-down, pull-up
These terms refer to resistors, sometimes internal to the device, which are
permanently connected to either ground or VDD.
PWM
Pulse width modulation. This term is used to describe a technique where the width of
the high and low periods of a waveform is varied, usually to enable a representation
of an analog value.
QFP
Quad flat pack package.
TPG
MOTOROLA
ii
GLOSSARY
MC68HC11PH8
248
RAM
Random access memory. Fast read and write, but contents are lost when the power
is removed.
RFI
Radio frequency interference.
RTI
Real-time interrupt.
ROM
Read-only memory. This type of memory is programmed during device manufacture
and cannot subsequently be altered.
RS-232C
A standard serial communications protocol.
SAR
Successive approximation register.
SCI
Serial communications interface.
Set
‘1’ — the logic one state; the opposite of ‘clear’.
Silicon glen
An area in the central belt of Scotland, so called because of the concentration of
semiconductor manufacturers and users found there.
Single chip mode
In this mode the device functions as a self contained unit, requiring only I/O devices
to complete a system.
SPI
Serial peripheral interface.
Test mode
This mode is intended for factory testing.
TTL
Transistor-transistor logic.
UART
Universal asynchronous receiver transmitter.
VCO
Voltage controlled oscillator.
Watchdog
see ‘COP’.
Wired-OR
A means of connecting outputs together such that the resulting composite output
state is the logical OR of the state of the individual outputs.
Word
Two bytes; 16 bits.
XIRQ
Non-maskable interrupt request. The overline indicates that this has an active-low
signal format.
TPG
MC68HC11PH8
GLOSSARY
MOTOROLA
iii
249
THIS PAGE INTENTIONALLY LEFT BLANK
TPG
MOTOROLA
iv
GLOSSARY
MC68HC11PH8
250
INDEX
In this index numeric entries are placed first; page references in italics indicate that the reference
is to a figure.
16-bit PWM 8-28
4XCLK 2-9 2-10
4XOUT pin 2-6
8-bit modulus timers 8-35
block diagram 8-36
clock select 8-37
interrupt source resolution 10-25
reset 10-9
T8ACR — 8-bit modulus timer A control reg. 8-38
T8ADR — 8-bit modulus timer A data reg. 8-38
T8BCR — 8-bit modulus timer B control reg. 8-39
T8BDR — 8-bit modulus timer B data reg. 8-39
T8CCR — 8-bit modulus timer C control reg. 8-40
T8CDR — 8-bit modulus timer C data reg. 8-40
,
A
A/D 9-1
accuracy of conversion 4-6
ADCTL — A/D control and status reg. 9-8
ADR1–ADR4 — A/D converter results reg. 9-10
block diagram 9-2
channels 9-7 9-9
charge pump 9-3
clocks 9-4
conversion 9-3 9-4 9-4 9-5 9-8
input pin 9-3
multiple-channel operation 9-8 9-9
multiplexer 9-2 9-7
OPTION — System configuration options reg. 1 9-5
overview 9-1
pins 9-1
reset 10-10
single-channel operation 9-7
STOP mode 9-10
synchronisation 9-4
WAIT mode 9-10
accumulators 11-2
ADCTL — A/D control and status reg. 9-8
addressing modes 11-7
address-mark wakeup 5-4
ADPU - bit in OPTION 9-5
ADR1–ADR4 — A/D converter results reg. 9-10
,
,
,
,
,
,
,
analog-to-digital converter - see A/D
AUTO - bit in PLLCR 2-9
B
baud rates
bootloader 3-2
SCI 5-6
BCS - bit in PLLCR 2-9
biphase coding 6-1 6-3
block diagrams
8-bit modulus timers 8-36
A/D 9-2
MC68HC(7)11PH8 1-3
MI BUS 6-5
PLL 2-6
pulse accumulator 8-24
PWM 8-29
SCI 5-3
SCI baud rate 5-1
SPI 7-2
timer 8-7
timer clock divider chains 8-5 8-6
bootloader 3-2 3-4 3-5
boundary conditions, PWM 8-34
BPPUE - bit in PPAR 4-11
BPROT — Block protect reg. 3-21
BPRT[5:0] - bits in BPROT 3-21
BRST - bit in SCBDH 5-6
BSPL - bit in SCBDH 5-6
BTST - bit in SCBDH 5-6
BULKP - bit in BPROT 3-21
BWC - bit in PLLCR 2-10
bypassing 2-2 2-7
BYTE - bit in PPROG 3-26
,
,
,
,
,
C
C-bit in CCR 11-5
CCF - bit in ADCTL 9-8
CCR — condition code reg. 11-4
TPG
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INDEX
MOTOROLA
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251
CD–CA - bits in ADCTL 9-9
CFORC — Timer compare force reg. 8-12
charge pump, A/D 9-3
CLK4X - bit in CONFIG 3-13
clock monitor 10-4 10-5
clock rate, MI BUS 6-7 6-9
clocks
4XCLK 2-9 2-10
A/D 9-4
CMOS compatible 2-3
E 2-3 3-19
monitor reset 10-4 10-5
PWM 8-30
SPI 7-4
ST4XCK 6-7
stretching 3-19
timer divider chains 8-5 8-6
CME - bit in OPTION 10-5
coherency, timer 8-12
CON12 - bit in PWCLK 8-28
CON34 - bit in PWCLK 8-28
concatenation, of PWM 8-28
CONFIG — System configuration reg. 3-12
programming 3-29
configuration 3-12
conversion, A/D 9-3 9-4 9-4 9-5
COP 8-2 8-23
CONFIG — Configuration control reg. 10-6
COPRST — Arm/reset COP timer circuitry reg. 10-3
enable 10-7
OPTION — System configuration options reg. 1 10-4
rates 10-3 10-5
reset 10-2 10-3 10-9
timeout 10-2
COPRST — Arm/reset COP timer circuitry reg. 10-3
corruption
of A/D 4-6
of memory 2-3
CPHA - bit in SPCR 7-3 7-4 7-7
CPOL - bit in SPCR 7-6
CPU 11-1
accumulators (A, B and D) 11-2
architecture 11-1
CCR — condition code reg. 11-4
index registers (IX, IY) 11-2
program counter (PC) 11-4
programming model 11-1
registers 11-1
reset 10-8
CR[1:0] - bits in OPTION 10-5
CSA[2:0] - bits in T8ACR 8-38
CSB[2:0] - bits in T8BCR 8-39
CSC[2:0] - bits in T8CCR 8-40
CSEL - bit in OPTION 9-6
CWOM - bit in OPT2 4-12
,
,
,
,
,
,
,
,
,
,
,
,
,
,
,
D
DAC 9-3
data format, SCI 5-2
data types 11-6
DDA[7:0] - bits in DDRA 4-2
DDB[7:0] - bits in DDRB 4-3
DDC[7:0] - bits in DDRC 4-4
DDD[5:0] - bits in DDRD 4-5
DDF[7:0] - bits in DDRF 4-7
DDG[7:0] - bits in DDRG 4-8
DDH[7:0] - bits in DDRH 4-9
DDRA — Data direction reg. for port A
DDRB — Data direction reg. for port B
DDRC — Data direction reg. for port C
DDRD — Data direction reg. for port D
DDRF — Data direction reg. for port F
DDRG — Data direction reg. for port G
DDRH — Data direction reg. for port H
development tools C-1
DIR - direct addressing mode 11-7
DISCP - bit in PWEN 8-32
DISE - bit in OPT2 3-20
DLY - bit in OPTION 3-17
mask option 3-17
duty cycle, PWM 8-34
DWOM - bit in SPCR 7-6
4-2
4-3
4-4
4-5
4-7
4-8
4-9
E
E clock pin 2-5
EDGxA and EDGxB - bits in TCTL2 8-9
EELAT - bit in PPROG 3-26
EEON - bit in CONFIG 3-14
EEPGM - bit in PPROG 3-26
EEPROM 3-25 3-28
erased state ($FF) 3-25
erasing 3-27 3-28
PPROG — EEPROM programming control reg. 3-25
security 3-30
EEx - bits in INIT2 3-16
eight bit modulus timers - see 8-bit modulus timers
ELAT - bit in EPROG 3-23
EPGM - bit in EPROG 3-24
EPROG — EPROM programming control reg. 3-23
EPROM 3-5 3-23 3-25
device 1-1
EPROG — EPROM programming control reg. 3-23
erased state ($FF) 3-23
programming 3-24
ERASE - bit in PPROG 3-26
erased state
EEPROM ($FF) 3-25
EPROM ($FF) 3-23
error detection, SCI 5-5
ESD protection A-1
EVEN - bit in PPROG 3-25
event counter - see pulse accumulator
–
–
,
–
TPG
MOTOROLA
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INDEX
MC68HC11PH8
252
EVS — Evaluation system C-1
EXCOL - bit in EPROG 3-24
EXROW - bit in EPROG 3-24
EXT4X - bit in OPT2 3-20
EXTAL pin 2-3
interrupts
8-bit modulus timers 10-25
I-bit 10-16 11-5
illegal opcode trap 10-16
IRQ 2-12
maskable 10-17
multiple sources 2-12
non-maskable 10-16
priorities 10-11
priority resolution 10-21
SCI 5-14 10-24
sensitivity 2-12
stacking 10-15
SWI 10-16
triggering 2-12
types 10-15
wired-OR 2-12
X-bit 10-16 11-6
XIRQ 2-12 10-16
IRQ pin 2-12
IRQE - bit in OPTION 3-17
IRVNE - bit in OPT2 3-19
,
F
FCME - bit in OPTION 10-5
FE - bit in SCSR1 5-11
FE2 - bit in S2SR1 5-16
FOC[1:5] - bits in CFORC 8-13
FPPUE - bit in PPAR 4-11
free-running counter 8-1
FREEZ - bit in CONFIG 3-13
,
,
,
G
GPPUE - bit in PPAR 4-11
GWOM - bit in SP2CR 2-17
J
H
H-bit in CCR 11-6
HPPUE - bit in PPAR 4-11
HPRIO — Highest priority I-bit interrupt & misc. reg. 3-11
I
I/O, on reset 10-8
I4/05 - bit in PACTL 8-10 8-25
I4/O5F - bit in TFLG1 8-16
I4/O5I - bit in TMSK1 8-15
I-bit in CCR 10-16 11-5
IC1F–IC3F - bits in TFLG1 8-16
IC1I–IC3I - bits in TMSK1 8-15
IDLE - bit in SCSR1 5-10
IDLE2 - bit in S2SR1 5-16
idle-line wakeup 5-4
IEH[7:0] - bits in WOIEH 4-10
ILIE - bit in SCCR2 5-9
ILIE2 - bit in S2CR2 5-16
illegal opcode trap 10-16
ILT - bit in SCCR1 5-8
ILT2 - bit in S2CR1 5-16
IMM - immediate addressing mode 11-7
IND, X/Y - indexed addressing modes 11-8
index registers (IX, IY) 11-2
INH - inherent addressing mode 11-8
INIT — RAM and I/O mapping reg. 3-14
INIT2 — EEPROM mapping and MI BUS delay reg. 6-8
initialization 3-12
input capture 8-8
instruction set 11-8
internal oscillator 3-17 9-4 9-5 A-16
,
,
,
,
junction temperature, chip A-2
L
LCD driver interface 7-1
LCD module 2-18
clock source 8-23
LCDBP - LCD backplane 2-18
LCDR — LCD control and data reg. 2-18
reset 10-10
LCD[7:4] - bits in LCDR 2-18
LCDBP - LCD backplane 2-18
LCDCK - bit in LCDR 2-19
LCDE - bit in LCDR 2-19
LCDR — LCD control and data reg. 2-18
LIR pin 2-13
LIRDV - bit in OPT2 3-18
LOOPS - bit in SCCR1 5-7
LOPS2 - bit in S2CR1 5-16
low power modes
RAM 3-5
stand-by connections 2-13
stand-by voltage 2-13
STOP 10-18
WAIT 10-17
low voltage inhibit circuit 2-3
LSBF - bit in OPT2 7-9
LVI 2-3
,
TPG
MC68HC11PH8
INDEX
MOTOROLA
vii
253
M
N
M - bit in SCCR1 5-8
M2 - bit in S2CR1 5-16
M2DL1:M2DL0 - bits in INIT2 6-8
Manchester coding 6-1 6-2 6-3
mask options 1-2
oscillator buffer type 2-4
PLL crystal frequency 2-7
ROMON bit 3-14
security 3-30
stabilization delay timing 3-17
maximum ratings A-1
MBE - bit in EPROG 3-23
MC68HC711PH8 1-1
MCS - bit in PLLCR 2-10
MDA - bit in HPRIO 3-11
memory
corruption of 2-3
EEPROM 3-25 3-28
EPROM 3-5 3-23 3-25
map 3-3
mapping 3-4 3-14 3-16
protection 3-21 3-30
RAM 3-4
RAM stand-by connections 2-13
register map 3-5
ROM 3-5
stretch external access 3-19
memory map, on reset 10-8
MI BUS 1-2 6-1
block diagram 6-5
clock rate 6-7 6-9
error detection 6-4
INIT2 — EEPROM mapping and MI BUS delay reg.
6-8
interface 6-6
Manchester coding 6-1 6-3
pins 6-1
pull field 6-3
push field 6-2
S2BDH, S2BDL — MI BUS clock rate control reg. 6-9
S2CR1 — MI BUS control reg. 1 6-9
S2CR2 — MI BUS2 control reg. 2 6-10
S2DRL — MI BUS2 data reg. 6-12
S2SR1 — MI BUS status reg. 1 6-11
S2SR2 — MI BUS2 status reg. 2 6-12
ST4XCK clock 6-7
timing 6-2
MIE2 - bit in S2CR1 5-16 6-9
MISO 7-4
MODA/LIR pin 2-13
MODB/VSTBY pin 2-13
MODF - bit in SPSR 7-8
modulus timers - see 8-bit modulus timers
MOSI 7-4
MSTR - bit in SPCR 7-5 7-6
MULT - bit in ADCTL 9-9
multiplexer, A/D 9-2 9-7
multiplication factor, PLL 2-11
N-bit in CCR 11-5
NF - bit in SCSR1 5-11
NF2 - bit in S2SR1 5-16 6-12
NMI 2-12 10-16
NOCOP - bit in CONFIG 10-7
noise 2-2 2-4 2-5 2-7
non-maskable interrupt 2-12
NOSEC - bit in CONFIG 3-31
,
–
,
,
,
,
–
–
,
,
,
,
,
,
,
,
,
,
,
O
OC1D — Output compare 1 data reg. 8-13
OC1D[7:3] - bits in OC1D 8-13
OC1F–OC4F - bits in TFLG1 8-16
OC1I–OC4I - bits in TMSK1 8-15
OC1M — Output compare 1 mask reg. 8-13
OC1M[7:3] - bits in OC1M 8-13
ODD - bit in PPROG 3-25
OL[2:5] - bits in TCTL1 8-14
OM[2:5] - bits in TCTL1 8-14
operating modes 3-1
baud rates 3-2
bootstrap 3-2
expanded 3-1
HPRIO register 3-11
selection of 2-13 3-10
single chip 3-1
STOP 3-5 10-18
test 3-2
VSTBY 3-5
WAIT 10-17
OPT2 — System configuration options reg. 2 3-18
OPTION — System configuration options reg. 1 9-5 10-4
OR - bit in SCSR1 5-11
OR2 - bit in S2SR1 5-16 6-11
ordering information B-6
oscillator 2-3
connections 2-4
output compare 8-11
overflow bit in CCR 11-5
,
,
,
,
P
packages
CERQUAD B-4
options 2-1
PLCC B-3
thermal characteristics A-1
TQFP B-5
PACNT — Pulse accumulator count reg. 8-26
PACTL — Pulse accumulator control reg. 8-25
PAEN - bit in PACTL 8-25
PAIF - bit in TFLG2 8-27
PAII - bit in TMSK2 8-27
PAMOD - bit in PACTL 8-25
TPG
MOTOROLA
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INDEX
MC68HC11PH8
254
PAOVF - bit in TFLG2 8-26
PAOVI - bit in TMSK2 8-26
PAREN - bit in CONFIG 4-13
PCKA[2:1] - bits in PWCLK 8-30
PCKB[3:1] - bits in PWCLK 8-30
PCLK[2:1] - bits in PWPOL 8-31
PCLK[4:3] - bits in PWPOL 8-31
PE - bit in SCCR1 5-8
PE2 - bit in S2CR1 5-16
PEDGE - bit in PACTL 8-25
PF - bit in SCSR1 5-11
PF2 - bit in S2SR1 5-16
phase-locked loop - see PLL
pinouts
CERQUAD 2-1
PLCC 2-1
TQFP 2-2
pins
4XOUT 2-6
E clock 2-5
EXTAL 2-3
IRQ 2-12
LIR 2-13
MODA/LIR 2-13
MODB/VSTBY 2-13
OC1, special features 8-4 8-11
R/W 2-13
RESET 2-3 10-2
VDD AD, VSS AD 2-2
VDD, VSS 2-2
VDDL, VDDR, VSSL, VSSR 2-2
VDDSYN 2-6
VPPE 2-12
VRH, VRL 2-13
VSTBY 2-13
XFC 2-6
XIRQ/VPPE 2-12
XTAL 2-3
PLL 2-6
bandwidth 2-7
block diagram 2-6
changing frequency 2-8
crystal frequency mask option 2-7
multiplication factor 2-11
PLLCR — PLL control reg. 2-9
synchronisation 2-8
SYNR — Synthesizer program reg. 2-11
VCOOUT 2-9
PLLCR — PLL control reg. 2-9
PLLCR — PLL control register 2-9
PLLON - bit in PLLCR 2-9
POR 10-1
stabilization delay 10-1
PORTA — Port A data reg. 4-2
PORTB — Port B data reg. 4-3
PORTC — Port C data reg. 4-4
PORTD — Port D data reg. 4-5
PORTE — Port E data reg. 4-6
PORTF — Port F data reg. 4-7
PORTG — Port G data reg. 4-8
,
,
PORTH — Port H data reg. 4-9
ports
A (Timer) 2-14 4-2
B (A[15:8], LCD) 2-14 4-3
C (D[7:0]) 2-16 4-4
D (SCI1, SPI1) 2-16 4-5
DDRA — Data direction reg. for port A 4-2
DDRB — Data direction reg. for port B 4-3
DDRC — Data direction reg. for port C 4-4
DDRD — Data direction reg. for port D 4-5
DDRF — Data direction reg. for port F 4-7
DDRG — Data direction reg. for port G 4-8
DDRH — Data direction reg. for port H 4-9
E (A/D) 2-17 4-6
F (A[7:0]) 2-17 4-7
G (R/W, SCI2, SPI2, LCD) 2-17 4-8
H (PWM, modulus timers) 2-18 4-9
PORTA — Port A data reg. 4-2
PORTB — Port B data reg. 4-3
PORTC — Port C data reg. 4-4
PORTD — Port D data reg. 4-5
PORTE — Port E data reg. 4-6
PORTF — Port F data reg. 4-7
PORTG — Port G data reg. 4-8
PORTH — Port H data reg. 4-9
signals 2-14
power-on reset - see POR
PPAR — Port pull-up assignment reg. 4-11
PPOL[4:1] - bits in PWPOL 8-31
PPROG — EEPROM programming control reg. 3-25
PR[1:0] - bits in TMSK2 3-22 8-17
PRB - bit in T8BCR 8-39
PRC - bit in T8CCR 8-40
prebyte 11-7
prescaler, PWM 8-30
priorities, resets and interrupts 10-11 10-12
program counter (PC) 11-4
programming
CONFIG 3-29
EEPROM 3-25
EPROM 3-24
protection
of memory 3-21 3-30
registers 3-10
PSEL[4:0] - bits in HPRIO 10-12
PT - bit in SCCR1 5-8
PT2 - bit in S2CR1 6-10
PTCON - bit in BPROT 3-21
pull field 6-3
pull-ups 4-11
pulse accumulator 8-1 8-23
block diagram 8-24
PACNT — Pulse accumulator count reg. 8-26
PACTL — Pulse accumulator control reg. 8-25
reset 10-9
TFLG2 — Timer interrupt flag 2 reg. 8-26
TMSK2 — Timer interrupt mask 2 reg. 8-26
pulse-width modulation - see PWM
push field 6-2
PWCLK — PWM clock prescaler and 16-bit select reg. 8-28
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,
,
TPG
MC68HC11PH8
INDEX
MOTOROLA
ix
255
PWCNT1–4 — PWM timer counter reg. 1 to 4 8-33
PWDTY1–4 — PWM timer duty cycle reg. 1 to 4 8-34
PWEN — PWM timer enable reg. 8-32
PWEN[4:1] - bits in PWEN 8-32
PWM 8-27
16-bit operation 8-28
block diagram 8-29
boundary conditions 8-34
clock select 8-30
duty cycle 8-27 8-34
periods 8-27
pins 8-27
PWCLK — PWM clock prescaler and 16-bit select reg.
8-28
PWCNT1–4 — PWM timer counter reg. 1 to 4 8-33
PWDTY1–4 — PWM timer duty cycle reg. 1 to 4 8-34
PWEN — PWM timer enable reg. 8-32
PWPER1–4 — PWM timer period reg. 1 to 4 8-33
PWPOL — PWM timer polarity & clock source select
reg. 8-31
PWSCAL — PWM timer prescaler reg. 8-31
PWPER1–4 — PWM timer period reg. 1 to 4 8-33
PWPOL — PWM timer polarity & clock source select reg.
8-31
PWSCAL — PWM timer prescaler reg. 8-31
,
resets (continued)
effect on LCD module 10-10
effect on memory map 10-8
effect on pulse accumulator 10-9
effect on RTI 10-9
effect on SCI 10-9
effect on SPI 10-10
effect on system 10-10
effect on timer 10-8
effects of 10-7
external 10-2
HPRIO — Highest priority I-bit interrupt and misc. reg.
10-12
power-on, POR 10-1
priorities 10-11
processing flow 10-19
RESET pin 10-2
resetting the COP watchdog 10-3
RFI 2-4 2-5
RIE - bit in SCCR2 5-9
RIE2 - bit in S2CR2 5-16 6-10
ROM 3-5
ROMAD - bit in CONFIG 3-12
ROMON - bit in CONFIG 3-14
mask option 3-14
ROW - bit in PPROG 3-26
RTI 8-2 8-19
PACTL — Pulse accumulator control reg. 8-22
rates 8-19
reset 10-9
TFLG2 — Timer interrupt flag reg. 2 8-21
TMSK2 — Timer interrupt mask reg. 2 8-20
RTIF - bit in TFLG2 8-21
RTII - bit in TMSK2 8-20
RTR[1:0] - bits in PACTL 8-22
RWU - bit in SCCR2 5-4 5-9
RWU2 - bit in S2CR2 5-16
,
,
,
R
,
R/T[7:0] - bits in S2DRL 5-17 6-12
R/T[7:0] - bits in SCDRL 5-12
R/W pin 2-13
R8 - bit in SCDRH 5-12
R8B - bit in S2DRH 5-17
RAF - bit in SCSR2 5-12
RAF2 - bit in S2SR2 5-17 6-12
RAM 3-4
data retention 3-5
security 3-30
RAM[3:0] - bit in INIT 3-14
ratiometric conversions 9-5
RBOOT - bit in HPRIO 3-11
RDRF - bit in SCSR1 5-10
RDRF2 - bit in S2SR1 5-16 6-11
RE - bit in SCCR2 5-9
RE2 - bit in S2CR2 5-16 6-10
real-time interrupt - see RTI
receiver flags, SCI 5-13
REG[3:0] - bit in INIT 3-15
REL - relative addressing mode 11-8
RESET pin 2-3
resets
circuit 2-3
clock monitor 10-4 10-5
COP 10-2 10-3
effect on 8-bit modulus timers 10-9
effect on A/D 10-10
effect on COP 10-9
effect on CPU 10-8
effect on I/O 10-8
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,
,
S
S2B[12:0] - bits in S2BDH/L 6-9
S2BDH, S2BDL — MI BUS clock rate control reg. 6-9
S2BDH, S2BDL — SCI2 baud rate control reg. 5-15
S2CR1 — MI BUS control reg. 1 6-9
S2CR1 — SCI2 control reg. 1 5-16
S2CR2 — MI BUS2 control reg. 2 6-10
S2CR2 — SCI2 control reg. 2 5-16
S2DRH, S2DRL — SCI2 data high/low reg. 5-17
S2DRL — MI BUS2 data reg. 6-12
S2SR1 — MI BUS status reg. 1 6-11
S2SR1 — SCI2 status reg. 1 5-16
S2SR2 — MI BUS2 status reg. 2 6-12
S2SR2 — SCI2 status reg. 2 5-17
S-bit in CCr 11-6
SBK - bit in SCCR2 5-9
SBK2 - bit in S2CR2 5-16 6-10
SBR[12:0] - bits in SCBDH/L 5-6
SCAN - bit in ADCTL 9-8
SCBDH, SCBDL — SCI baud rate control reg. 5-6
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TPG
MOTOROLA
x
INDEX
MC68HC11PH8
256
SCCR1 — SCI control reg. 1 5-7
SCCR2 — SCI control reg. 2 5-9
SCDRH, SCDRL — SCI data high/low reg. 5-12
SCI 5-1
baud rate 5-1 5-6
block diagram 5-3
data format 5-2
error detection 5-5
interrupt source resolution 5-14 10-24
pins 5-1
receive operation 5-2
reset 10-9
SCBDH, SCBDL — SCI baud rate control reg. 5-6
SCCR1 — SCI control reg. 1 5-7
SCCR2 — SCI control reg. 2 5-9
SCDRH, SCDRL — SCI data high/low reg. 5-12
SCSR1 — SCI status reg. 1 5-10
SCSR2 — SCI status reg. 2 5-12
status flags 5-13
transmit operation 5-2
wakeup 5-4
SCI2 - see also SCI 5-15
SCK 7-4
SCSR1 — SCI status reg. 1 5-10
SCSR2 — SCI status reg. 2 5-12
security 3-30
mask option 3-30
NOSEC bit 3-31
sensitivity, of interrupts 2-12 3-17
serial communications interface - see SCI
serial peripheral interface - see SPI
slave select (SS) 7-4
slow memory 3-19
SMOD - bit in HPRIO 3-11
software interrupt (SWI) 10-16
SP2CR — SPI2 control reg. 7-11
SP2DR — SPI2 data reg. 7-11
SP2OPT — SPI2 control options reg. 7-11
SP2SR — SPI2 status reg. 7-11
SPCR — Serial peripheral control reg. 7-6
SPDR — SPI data reg. 7-8
SPE - bit in SPCR 7-6
SPI 7-1
block diagram 7-2
buffering 7-1 7-8
clock phase 7-3
clock polarity 7-6
clock rate 7-4 7-7
errors 7-5
master mode 7-6
MISO 7-4
MOSI 7-4
OPT2 — System configuration options reg. 2 7-9
pins 7-1
polarity 7-3
reset 10-10
SCK 7-4
signals 7-3
SPCR — Serial peripheral control reg. 7-6
SPDR — SPI data reg. 7-8
,
,
SPI (continued)
SPSR — Serial peripheral status reg. 7-7
SS 7-4
transfer formats 7-2 7-3
SPI2 - see also SPI 7-10
SPIE - bit in SPCR 7-5 7-6
SPIF - bit in SPSR 7-7
SPR1 and SPR0 - bits in SPCR 7-7
SPR2 - bit in OPT2 7-9
SPSR — Serial peripheral status reg. 7-7
ST4XCK clock 6-7
stack pointer (SP) 11-2
stacking operations 11-3
stand-by voltage 2-13
status flags, SCI 5-13
STOP mode 3-5 10-18
disabling 11-6
stabilization delay 3-17
STRCH - bit in OPT2 3-19
stretch, external access 3-19
STRX - bit in INIT2 3-16
SWI 10-16
synchronisation, A/D 9-4
SYNR — Synthesizer program reg. 2-11
SYNX[1:0] - bits in SYNR 2-11
SYNY[5:0] - bits in SYNR 2-11
system reset 10-10
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T
T16EN - bit in PLLCR 8-4
T8 - bit in SCDRH 5-12
T8ACR — 8-bit modulus timer A control reg. 8-38
T8ADR — 8-bit modulus timer A data reg. 8-38
T8AF - bit in T8ACR 8-38
T8AI - bit in T8ACR 8-38
T8B - bit in S2DRL 5-17
T8BCR — 8-bit modulus timer B control reg. 8-39
T8BDR — 8-bit modulus timer B data reg. 8-39
T8BF - bit in T8BCR 8-39
T8BI - bit in T8BCR 8-39
T8CCR — 8-bit modulus timer C control reg. 8-40
T8CDR — 8-bit modulus timer C data reg. 8-40
T8CF - bit in T8CCR 8-40
T8CI8 - bit in T8CCR 8-40
TC - bit in SCSR1 5-10
TC2 - bit in S2SR1 5-16
TCIE - bit in SCCR2 5-9
TCIE2 - bit in S2CR2 5-16
TCNT — Timer counter reg. 8-14
TCTL1 — Timer control reg. 1 8-14
TCTL2 — Timer control reg. 2 8-9
TDRE - bit in SCSR1 5-10
TDRE2 - bit in S2SR1 5-16
TE - bit in SCCR2 5-9
TE2 - bit in S2CR2 5-16 6-10
test methods A-3
TFLG1 — Timer interrupt flag reg. 1 8-16
TFLG2 — Timer interrupt flag reg. 2 8-18
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TPG
MC68HC11PH8
INDEX
MOTOROLA
xi
257
TI4/O5 — Timer input capture 4/output compare 5 reg. 8-10
TIC1–TIC3 — Timer input capture reg. 8-10
TIE - bit in SCCR2 5-9
TIE2 - bit in S2CR2 5-16
time accumulation - see pulse accumulator
timer 8-1
block diagram 8-7
CFORC — Timer compare force reg. 8-12
clock divider chains 8-5 8-6
coherency 8-12
COP 8-23
free-running counter 8-1
input capture 8-8
OC1, special features 8-4 8-11
OC1D — Output compare 1 data reg. 8-13
OC1M — Output compare 1 mask reg. 8-13
output compare 8-11
pins 8-4
prescaler 8-1
reset 10-8
TCNT — Timer counter reg. 8-14
TCTL1 — Timer control reg. 1 8-14
TCTL2 — Timer control reg. 2 8-9
TFLG1 — Timer interrupt flag reg. 1 8-16
TFLG2 — Timer interrupt flag reg. 2 8-18
TI4/O5 — Timer input capture 4/output compare 5 reg.
8-10
TIC1–TIC3 — Timer input capture reg. 8-10
TMSK1 — Timer interrupt mask reg. 1 8-15
TMSK2 — Timer interrupt mask reg. 2 3-22 8-17
TOC1–TOC4 — Timer output compare reg. 8-12
TMSK1 — Timer interrupt mask reg. 1 8-15
TMSK2 — Timer interrupt mask reg. 2 3-22 8-17
TOC1–TOC4 — Timer output compare reg. 8-12
TOF - bit in TFLG2 8-18 8-21
TOI - bit in TMSK2 8-17
TPWSL - bit in PWEN 8-32
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,
,
W
,
WAIT mode 2-10 10-17
WAKE - bit in SCCR1 5-8
WAKE2 - bit in S2CR1 5-16
wakeup, SCI 5-4
watchdog - see COP
WCOL - bit in SPSR 7-8
WEN - bit in PLLCR 2-10
wired_OR 2-17
wired-OR 2-12 2-16 3-2 4-12
wired-OR interrupt 4-10
WOIEH — Wired-OR interrupt enable reg. 4-10
WOMS - bit in SCCR1 5-7
WOMS2 - bit in S2CR1 2-17 5-16 6-9
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X
,
X-bit in CCR 10-16 11-6
XFC pin 2-6
XIRQ 10-16
XIRQ/VPPE 2-12
xPPUE - bits in PPAR 4-11
XTAL pin 2-3
Z
Z-bit in CCR 11-5
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,
U
UART 5-1
V
V-bit in CCR 11-5
VCOOUT 2-9
VCOT - bit in PLLCR 2-10
VDD AD, VSS AD pins 2-2
VDD pin 2-2
VDDL, VDDR, VSSL, VSSR pins 2-2
VDDSYN pin 2-6
VPPE pin 2-12
VRH, VRL pins 2-13
VSS pin 2-2
VSTBY pin 2-13
TPG
MOTOROLA
xii
INDEX
MC68HC11PH8
258
INTRODUCTION
1
PIN DESCRIPTIONS
2
OPERATING MODES AND ON-CHIP MEMORY
3
PARALLEL INPUT/OUTPUT
4
SERIAL COMMUNICATIONS INTERFACE
5
MOTOROLA INTERCONNECT BUS (MI BUS)
6
SERIAL PERIPHERAL INTERFACE
7
TIMING SYSTEM
8
ANALOG-TO-DIGITAL CONVERTER
9
RESETS AND INTERRUPTS
10
CPU CORE AND INSTRUCTION SET
11
ELECTRICAL SPECIFICATIONS (STANDARD)
A
MECHANICAL DATA AND ORDERING INFORMATION
B
DEVELOPMENT SUPPORT
C
TPG
259
1
INTRODUCTION
2
PIN DESCRIPTIONS
3
OPERATING MODES AND ON-CHIP MEMORY
4
PARALLEL INPUT/OUTPUT
5
SERIAL COMMUNICATIONS INTERFACE
6
MOTOROLA INTERCONNECT BUS (MI BUS)
7
SERIAL PERIPHERAL INTERFACE
8
TIMING SYSTEM
9
ANALOG-TO-DIGITAL CONVERTER
10
RESETS AND INTERRUPTS
11
CPU CORE AND INSTRUCTION SET
A
ELECTRICAL SPECIFICATIONS (STANDARD)
B
MECHANICAL DATA AND ORDERING INFORMATION
C
DEVELOPMENT SUPPORT
TPG
260
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
How to reach us:
Mfax™: [email protected] – TOUCHTONE (602) 244-6609
INTERNET: http://www.mot.com/SPS/
USA/EUROPE: Motorola Literature Distribution; P.O. Box 5405; Denver, Colorado 80217. 303-675-2140
JAPAN: Nippon Motorola Ltd.; Tatsumi-SPD-JLDC, Toshikatsu Otsuki, 6F Seibu-Butsuryu-Center,
3-14-2 Tatsumi Koto-Ku, Tokyo 135, Japan. 81-3-3521-8315
HONG KONG: Motorola Semiconductors H.K. Ltd.; 8B Tai Ping Industrial Park, 51 Ting Kok Road,
Tai Po, N.T., Hong Kong. 852-26629298