Software and Hardware Engineering: Motorola M68HC11, together with Microcontrollers and Microcomputers: Principles of Software and Hardware Engineering, is designed to give the student a fundamental understanding of a microcomputer-based system. The material is aimed at the sophomore, junior or senior level Electrical Engineering, Electrical Engineering Technology or Computer Science student taking a first course in microcomputers. Prerequisites are a digital logic course and a first course in a programming language.

The overall objective for this text is to provide an introduction to the architecture and design of hardware and software for the Motorola M68HC11. Although Software and Hardware Engineering: Motorola M68HC11 is designed to accompany a text explaining the general principles of software and hardware engineering, it can stand alone as a reference for M68HC11 users. It gives many programming and hardware interfacing examples that will enable students to become accomplished software and hardware designers. Of course, no one should expect to become an expert in using the M68HC11 in a single course.

The following study plan, summarized in Table I, will help the reader become familiar with the principles of microcomputer systems and to learn about the M68HC11 microcontroller as an example. A well designed course should have the student learn general design principles illustrated by examples of a specific processor. Table I shows how one could combine this text with Microcontrollers and Microcomputers: Principles of Software and Hardware Engineering to give the student a reference than can be used when applying other processors later in his or her career.

Two useful appendices are included. Appendix A gives a list of references pointing the reader toward more information about the M68HC11. There is a wealth of information to be gleaned from the Internet and from Motorola application notes. Appendix B explains the versions of the M68HC11 microcontroller family.

In addition to covering the features common to all members of the M68HC11 family of microcontrollers, advanced features are discussed. These include the pulse-width modulator in Chapter 10, the 16-bit math coprocessor in Chapter 13, and the 8-bit digital-to-analog converter in Chapter 12. The enhanced Serial Communications Interface (SCI) and Serial Peripheral Interface (SPI) are discussed in Chapter 11.

The following study plan will help the reader become familiar with the principles of microcomputer systems and to learn about the M68HC11 microcontroller as an example. Table I shows how one could combine this text with Microcontrollers and Microcomputers: Principles of Software and Hardware Engineering to give the student a reference than can be used when applying other processors later in his or her career.

Study Goals	Microcontrollers and Microcomputers: Principles of Software and Hardware Engineering	Software and Hardware Engineering: Motorola M68HC11
Overview	Chapter 1. Introduction	Chapter 1. Introduction
Learn about the architecture of stored program computer.	Chapter 2. The Picoprocessor: An Introduction to Computer Architecture	.
Learn about different registers in a CPU and how the codes used for various information affect how we interpret the Condition Code Register.	Chapter 3. Introduction to the CPU: Registers and Condition Codes	Chapter 2. Introduction to the M68HC11 Hardware
Learn about the various ways a CPU can address memory.	Chapter 4. Addressing Modes	.
Learn how an assembler works and some of the techniques of programming in assembly language. Learn how to operate your laboratory assembler.	Chapter 5. Assembly Language Programming and Debugging	Chapter 3. Motorola AS11 Assembler
See how instructions can be grouped into categories that help make your beginning programming tasks easier.	.	Chapter 4. Introduction to the M68HC11 Instruction Set
Learn how to debug assembly language programs.	.	Chapter 5. Buffalo Monitor and Debugger
Learn how to properly design more complex software.	Chapter 6. Top Down Software Design	.
Develop good assembly language programming style.	.	Chapter 6. AS11 Programs for the M68HC11
Learn about parallel data transfer, timing, addressing and I/O interfaces.	Chapter 7. Computer Buses and Parallel Input/Output	Chapter 7. M68HC11 Parallel I/O.
Learn about interrupts and interrupt service routines.	Chapter 8. Interrupts and Real-Time Events	Chapter 8. M68HC11 Interrupts
Learn about the different types of memory and how the organization of the memory is affected by the type of computer system being designed.	Chapter 9. Computer Memories	Chapter 9. M68HC11 Memories
Many interrupts in real-time systems are generated by timer circuits. In this chapter we learn about the timer in the M68HC11.	.	Chapter 10. M68HC11 Timer
The elements of serial I/O are quite simple and yet serial interfacing is frustrating. These chapters will help you learn how to deal with the problems of serial interfacing.	Chapter 10. Serial Input/Output	Chapter 11. M68HC11 Serial I/O
Information in the real world is often analog. This chapter will show you how various A/D and D/A devices work and how to specify either in a system.	Chapter 11. Analog Input and Output	Chapter 12. M68HC11 Analog Input and Output.
This chapter is a general look at more advanced hardware features of your laboratory microprocessor.	.	Chapter 13. Advanced M68HC11 Hardware
The final exam is a look at the Motorola M68HC11EVB Evaluation Board.	.	Chapter 14. The Motorola M68HC11EVB Evaluation Board

TABLE OF CONTENTS

CHAPTER 1.	INTRODUCTION

1.1	INTRODUCTION	  1
1.2	COMPUTERS, MICROPROCESSORS, MICROCOMPUTERS, MICROCONTROLLERS	  1
1.3	SOME BASIC DEFINITIONS	  3
1.4	NOTATION	  3
1.5	BIBLIOGRAPHY AND FURTHER READING	  4
1.6	REFERENCES	  4

CHAPTER 2.	INTRODUCTION TO THE M68HC11 HARDWARE

2.1	CHAPTER PRE-STUDY MATERIAL	  5
2.2	INTRODUCTION	  5
2.3	CPU AND REGISTERS	  8
	THE PROGRAMMER'S CPU MODEL	  8
	CONTROL REGISTERS	  10
2.4	ADDRESSING MODES	  13
	IMMEDIATE ADDRESSING	  13
	DIRECT AND EXTENDED ADDRESSING	  13
	INDEXED ADDRESSING	  14
	INHERENT ADDRESSING	  15
	RELATIVE ADDRESSING	  16
2.5	RESET	  16
	THE RESET ACTION	  17
	CAUSES OF RESET	  18
	RESET SUMMARY	  18
2.6	CONCLUSION AND CHAPTER SUMMARY POINTS	  18
2.7	BIBLIOGRAPHY AND FURTHER READING	  19
2.8	PROBLEMS	  19


CHAPTER 3.	MOTOROLA AS11 ASSEMBLER

3.1	ASSEMBLY LANGUAGE EXAMPLE	  21
3.2	M68HC11 AS11 ASSEMBLER	  23
3.3	ASSEMBLER SOURCE CODE FIELDS	  23
	LABEL FIELD	  23
	OPCODE OR OPERATION FIELD	  25
	OPERAND FIELD	  25
	COMMENT FIELD	  31
3.4	ASSEMBLER DIRECTIVES	  31
	SET THE PROGRAM COUNTER	  32
	DEFINING SYMBOLS	  33
	RESERVING MEMORY LOCATIONS	  34
	DEFINING CONSTANTS IN MEMORY	  35
	MISCELLANEOUS DIRECTIVES	  38
3.5	ASSEMBLER OUTPUT FILES	  39
3.6	ASSEMBLER INVOCATION	  40
3.7	ASSEMBLER ERROR MESSAGES	  41
3.8	CHAPTER SUMMARY POINTS	  41
3.9	PROBLEMS	  42

CHAPTER 4.	THE M68HC11 INSTRUCTION SET

4.1	INTRODUCTION	  44
4.2	M68HC11 INSTRUCTION SET CATEGORIES	  44
4.3	LOAD AND STORE REGISTER INSTRUCTIONS	  47
	EIGHT-BIT LOAD AND STORE INSTRUCTIONS	  48
	SIXTEEN-BIT LOAD AND STORE INSTRUCTIONS	  51
	STACK INSTRUCTIONS	  52
4.4	TRANSFER REGISTER INSTRUCTIONS	  56
4.5	DECREMENT AND INCREMENT INSTRUCTIONS	  58
4.6	CLEAR AND SET INSTRUCTIONS	  61
4.7	SHIFT AND ROTATE INSTRUCTIONS	  66
4.8	ARITHMETIC INSTRUCTIONS	  72
	ADD AND SUBTRACT	  72
	DECIMAL ARITHMETIC	  75
	NEGATING INSTRUCTIONS	  77
	MULTIPLICATION	  77
	FRACTIONAL NUMBER ARITHMETIC	  78
	DIVISION	  79
	MATHEMATICS COPROCESSOR	  80
4.9	LOGIC INSTRUCTIONS	  81
4.10	DATA TEST INSTRUCTIONS	  83
4.11	CONDITIONAL BRANCH INSTRUCTIONS	  85
	SIGNED AND UNSIGNED CONDITIONAL BRANCHES	  86
4.12	UNCONDITIONAL JUMP AND BRANCH INSTRUCTIONS	  88
	BRANCHES TO SUBROUTINES 	  89
4.13	CONDITION CODE REGISTER INSTRUCTIONS	  90
4.14	INTERRUPT INSTRUCTIONS	  93
4.15	MISCELLANEOUS INSTRUCTIONS	  93
4.16	ADVANCED INSTRUCTION SET DETAILS	  94
4.17	CHAPTER SUMMARY POINTS	  94
4.18	BIBLIOGRAPHY AND FURTHER READING	  94
4.19	PROBLEMS	  95

CHAPTER 5.	BUFFALO MONITOR AND DEBUGGER

5.1	M68HC11 EVB BUFFALO MONITOR	  99
	ENTERING THE MONITOR	  99
	COMMAND LINE FORMAT	  100
5.2	MONITOR COMMANDS	  100
5.3	MONITOR UTILITY ROUTINES	  106
5.4	BUFFALO MONITOR INTERRUPT JUMP VECTOR TABLE	  107
5.5	OPERATING HINTS FOR THE BUFFALO MONITOR	  109
5.6	PROBLEMS	  109

CHAPTER 6.	AS11 PROGRAMS FOR THE M68HC11

6.1	ASSEMBLY LANGUAGE PROGRAMMING STYLE	  111
	SOURCE CODE STYLE	  111
	TO INDENT OR NOT TO INDENT	  118
	UPPER AND LOWER CASE	  118
	USE EQUATES, NOT MAGIC NUMBERS	  119
	USING BOILERPLATE FILES	  120
	USING MONITOR ROUTINES	  120
	COMMENTING STYLE	  120
	SUBROUTINE OR FUNCTION HEADERS	  121
6.2	STRUCTURED ASSEMBLY LANGUAGE PROGRAMMING	  121
	SEQUENCE	  121
	DECISION	  122
	WHILE-DO REPETITION	  124
	DO-WHILE REPETITION 	  126
6.3	EXAMPLE PROGRAMS	  128
6.4	CONCLUSION AND CHAPTER SUMMARY POINTS	  134
6.5	BIBLIOGRAPHY AND FURTHER READING	  135
6.6	PROBLEMS	  135

CHAPTER 7.	M68HC11 PARALLEL I/O

7.1	INTRODUCTION	  138
7.2	OPERATING MODES	  140
	NORMAL SINGLE-CHIP MODE	  140
	NORMAL EXPANDED-MODE	  141
7.3	THE PROGRAMMER'S MODEL	  145
7.4	M68HC11 PARALLEL I/O PORTS	  146
	PORT B	  146
	PORT A	  146
	PORT C	  148
	PORT D	  153
	PORT E	  155
7.5	HANDSHAKING I/O	  156
	SIMPLE STROBED I/O	  156
	FULL HANDSHAKING I/O	  159
7.6	I/O SOFTWARE	  166
	REAL-TIME SYNCHRONIZATION	  167
	POLLED I/O	  169
7.7	CHAPTER SUMMARY POINTS	  169
7.8	BIBLIOGRAPHY AND FURTHER READING	  170
7.9	PROBLEMS	  170

CHAPTER 8.	M68HC11 INTERRUPTS

8.1	INTRODUCTION	  172
8.2	THE INTERRUPT PROCESS	  173
	THE INTERRUPT ENABLE	  173
	THE INTERRUPT DISABLE	  173
	THE INTERRUPT REQUEST	  173
	THE INTERRUPT SEQUENCE	  174
	THE INTERRUPT RETURN	  175
8.3	INTERRUPT VECTORS	  175
	DEDICATED SYSTEM VECTORS	  175
	BUFFALO MONITOR INTERRUPT VECTOR JUMP TABLE	  177
8.4	INTERRUPT PRIORITIES	  179
8.5	NONMASKABLE INTERRUPTS 	  181
	SOFTWARE INTERRUPT - SWI	  182
	CLOCK MONITOR FAILURE	  182
	COP FAILURE	  182
	ILLEGAL OPCODE TRAP	  182
	NONMASKABLE INTERRUPT REQUESTQ	  182
8.6	PARALLEL I/O SYSTEM INTERRUPTS	  183
	OTHER INTERNAL INTERRUPT SOURCES	  186
8.7	ADVANCED INTERRUPTS	  186
	SHAREDQ AND PARALLEL I/O INTERRUPT VECTOR	  186
	POLLING FOR MULTIPLE EXTERNAL DEVICES	  187
	SELECTING EDGE OR LEVEL TRIGGERING	  187
	WHAT TO DO WHILE WAITING FOR AN INTERRUPT	  187
8.8	THE INTERRUPT SERVICE ROUTINE	  188
	INTERRUPT SERVICE ROUTINE HINTS	  189
	A DEDICATED SYSTEM ISR EXAMPLE	  191
	BUFFALO MONITOR ISR EXAMPLES	  194
8.9	CONCLUSION AND CHAPTER SUMMARY POINTS	  196
8.10	BIBLIOGRAPHY AND FURTHER READING	  197
8.11	PROBLEMS	  197


CHAPTER 9.	M68HC11 MEMORIES

9.1	INTRODUCTION	  199
9.2	M68HC11 MEMORY MAP	  199
9.3	M68HC11 RAM	  200
9.4	M68HC11 ROM	  202
9.5	M68HC11 EPROM	  202
9.6	M68HC11 EEPROM	  202
	EEPROM READING	  203
	EEPROM PROGRAMMING REGISTER	  203
	EEPROM PROGRAMMING VOLTAGE	  204
	EEPROM PROGRAMMING	  204
	EEPROM ERASING	  206
9.7	MEMORY TIMING IN EXPANDED-MODE OPERATION	  208
9.8	EXTENDING M68HC11 MEMORY ADDRESSES	  211
9.9	CONCLUSION AND CHAPTER SUMMARY POINTS	  220
9.10	BIBLIOGRAPHY AND FURTHER READING	  220
9.11	PROBLEMS	  220

CHAPTER 10.	M68HC11 TIMER

10.1	INTRODUCTION	  221
10.2	BASIC TIMER	  223
	SIXTEEN-BIT FREE-RUNNING TCNT REGISTER	  224
	TIMER OVERFLOW FLAG	  225
	TIMER OVERFLOW INTERRUPTS	  226
10.3	OUTPUT COMPARE	  229
	OUTPUT COMPARE TIME DELAYS	  230
	OUTPUT COMPARE INTERRUPTS	  231
	OUTPUT COMPARE BIT OPERATION	  234
	ONE OUTPUT COMPARE CONTROLLING UP TO FIVE OUTPUTS 	  235
	VERY SHORT DURATION PULSES 	  236
	FORCED OUTPUT COMPARES	  238
10.4	INPUT CAPTURE	  238
10.5	REAL-TIME INTERRUPT	  242
10.6	COMPUTER OPERATING PROPERLY - COP	  244
10.7	PULSE ACCUMULATOR	  246
	PULSE ACCUMULATOR INTERRUPTS	  248
10.8	PULSE-WIDTH MODULATION	  250
	PULSE-WIDTH MODULATOR CLOCK CONTROL	  251
	PULSE-WIDTH MODULATION CONTROL REGISTERS	  252
	CHOOSING PULSE-WIDTH MODULATION PRE-SCALE VALUES	  256
10.9	EXTERNAL INTERRUPTS USING TIMER INTERRUPTS	  260
10.10	CLEARING TIMER FLAGS	  260
10.11	CONCLUSION AND CHAPTER SUMMARY POINTS	  261
10.12	PROBLEMS	  262

CHAPTER 11.	M68HC11 SERIAL I/O

11.1	INTRODUCTION	  264
11.2	ASYNCHRONOUS SERIAL COMMUNICATIONS INTERFACE - SCI
	SCI DATA	  265
	SCI INITIALIZATION	  266
	SCI STATUS FLAGS	  269
	SCI INTERRUPTS	  271
	SCI WAKE UP	  273
	SCI BREAK CHARACTER	  275
	SCI PROGRAMMING EXAMPLE	  275
11.3	ENHANCED SCI	  277
11.4	SYNCHRONOUS SERIAL PERIPHERAL INTERFACE - SPI	  279
	INTERPROCESSOR SERIAL COMMUNICATIONS	  279
	SPI DATA REGISTER	  280
	SPI INITIALIZATION	  280
	SPI STATUS REGISTER AND INTERRUPTS	  284
	SPI INTERRUPTS	  285
11.5	ENHANCED SPI	  286
11.6	CONCLUSION AND CHAPTER SUMMARY POINTS	  287
11.7	BIBLIOGRAPHY AND FURTHER READING	  288
11.8	PROBLEMS	  288

CHAPTER 12.  M68HC11 ANALOG INPUT AND OUTPUT

12.1	INTRODUCTION	  290
12.2	M68HC11 A/D CONVERTER	  290
	A/D INITIALIZATION	  292
	A/D OPERATION	  294
12.3	A/D I/O SYNCHRONIZATION	  296
12.4	A/D PROGRAMMING EXAMPLE	  296
12.5	DIGITAL-TO-ANALOG CONVERTER	  297
12.6	CHAPTER SUMMARY POINTS	  298
12.7	BIBLIOGRAPHY AND FURTHER READING	  299
12.8	PROBLEMS	  299

CHAPTER 13.  ADVANCED M68HC11 HARDWARE

13.1	HARDWARE MODE SELECT	  300
	SPECIAL TEST MODE	  301
	SPECIAL BOOTSTRAP MODE	  301
13.2	CONFIGURATION CONTROL REGISTER	  302
13.3	SYSTEM OPTION REGISTER	  304
13.4	SECURITY MODE	  305
13.5	M68HC11 MATH COPROCESSOR	  306
	MATH COPROCESSOR OPERATIONS	  310
	MATH COPROCESSOR INTERRUPTS	  315
13.6	BIBLIOGRAPHY AND FURTHER READING	  316

CHAPTER 14.  THE MOTOROLA M68HC11EVB EVALUATION BOARD

14.1	INTRODUCTION	  317
14.2	EVB COMPONENTS AND CIRCUITS	  317
	MCU I/O PORT CONNECTOR	  319
	POWER SUPPLY	  321
	RESET CIRCUIT	  321
	CPU CRYSTAL CLOCK OSCILLATOR	  322
	M68HC11	  322
14.3	I/O PORTS	  322
	PORT A	  322
	PORT B AND PORT C	  322
	PORT D	  322
	PORT E	  323
	INTERRUPTS	  323
14.4	M68HC11 EXPANDED MODE	  323
	ADDRESS DECODING	  324
	EXTERNAL ROM	  324
	EXTERNAL RAM/EPROM SOCKET	  324
	EXTERNAL RAM	  325
	M68HC24 PORT REPLACEMENT UNIT	  325
	E-CLOCK	  325
14.5	SERIAL I/O INTERFACE	  325
	M6850 ASYNCHRONOUS COMMUNICATION INTERFACE ADAPTER	  325
	RS-232-C INTERFACE	  326
14.6	CHAPTER SUMMARY POINTS	  326
14.7	BIBLIOGRAPHY AND FURTHER READING	  326

APPENDIX A.	M68HC11 RESOURCES

A.1	INTERNET RESOURCES	  327
	THE WORLD WIDE WEB	  327
	EMAIL LIST SERVERS	  328
	FTP	  329
A.2	MOTOROLA APPLICATION NOTES AND LITERATURE	  330
A.3	HARDWARE AND SOFTWARE VENDORS	  331

APPENDIX B.  M68HC11 FAMILY

B.1	THE M68HC11 FAMILY OF MICROCONTROLLERS	  332
B.2	M68HC11 PART NUMBERING AND PACKAGING	  334

ANSWERS TO CHAPTER PROBLEMS	495

INDEX