PIC Microcontrollers · PIC Microcontrollers An Introduction to Microelectronics 3rd Edition Martin Bates AMSTERDAM † BOSTON † HEIDELBERG † LONDON NEW YORK † …

PIC Microcontrollers

PIC MicrocontrollersAn Introduction to Microelectronics

3rd Edition

Martin Bates

AMSTERDAM • BOSTON • HEIDELBERG • LONDON

NEW YORK • OXFORD • PARIS • SAN DIEGO

SAN FRANCISCO • SINGAPORE • SYDNEY • TOKYO

Newnes is an imprint of Elsevier

Newnes is an imprint of ElsevierThe Boulevard, Langford Lane, Kidlington, Oxford, OX5 1GB225 Wyman Street, Waltham, MA 02451, USA

First published 2011

Copyright � 2012 Martin Bates. Published by Elsevier Ltd. All rights reserved.

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This book and the individual contributions contained in it are protected under copyright by the Publisher (other thanas may be noted herein).

NoticesKnowledge and best practice in this field are constantly changing. As new research and experience broaden ourunderstanding, changes in research methods, professional practices, or medical treatment may become necessary.

Practitioners and researchers must always rely on their own experience and knowledge in evaluating and using anyinformation, methods, compounds, or experiments described herein. In using such information or methods theyshould be mindful of their own safety and the safety of others, including parties for whom they have a professionalresponsibility.

To the fullest extent of the law, neither the Publisher nor the authors, contributors, or editors, assume any liability forany injury and/or damage to persons or property as a matter of products liability, negligence or otherwise, or fromany use or operation of any methods, products, instructions, or ideas contained in the material herein.

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Library of Congress Number: 2011930131

ISBN: 978-0-080-96911-4

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Contents

Preface to the 3rd Edition................................................................................... ixIntroduction to the 3rd Edition ............................................................................ xi

Part 1 Getting Started

Chapter 1: Computer Systems ............................................................................ 3

1.1. Personal Computer System....................................................................................51.2. Word-Processor Operation ...................................................................................101.3. Microprocessor Systems ......................................................................................131.4. Microcontroller Applications...............................................................................17

Chapter 2: Microcontroller Operation ................................................................27

2.1. Microcontroller Architecture ...............................................................................282.2. Program Operations .............................................................................................33

Chapter 3: A Simple PIC Application .................................................................45

3.1. Hardware Design..................................................................................................463.2. Program Execution...............................................................................................503.3. Program BIN1 ......................................................................................................523.4. Assembly Language.............................................................................................55

Chapter 4: PIC Program Development ...............................................................61

4.1. Program Development .........................................................................................624.2. Program Design....................................................................................................654.3. Program Editing ...................................................................................................674.4. Program Structure ................................................................................................724.5. Program Analysis .................................................................................................744.6. Program Assembly...............................................................................................784.7. Program Simulation .............................................................................................824.8. Program Downloading .........................................................................................854.9. Program Testing ...................................................................................................88

v

Part 2 PIC Microcontrollers

Chapter 5: PIC Architecture..............................................................................93

5.1. Block Diagram ..................................................................................................... 955.2. Program Execution...............................................................................................965.3. File Register Set...................................................................................................98

Chapter 6: Programming Techniques ................................................................ 107

6.1. Program Timing ................................................................................................. 1096.2. Hardware Counter/Timer ................................................................................... 1096.3. Interrupts ............................................................................................................ 1156.4. Register Operations............................................................................................ 1226.5. Special Features ................................................................................................. 1296.6. Assembler Directives ......................................................................................... 1326.7. Pseudo-Instructions ............................................................................................ 1386.8. Numerical Types ................................................................................................ 1386.9. Data Table .......................................................................................................... 140

Chapter 7: PIC Development Systems .............................................................. 143

7.1. In-Circuit Programming..................................................................................... 1447.2. PICkit2 Demo System ....................................................................................... 1457.3. PIC 16F690 Chip ............................................................................................... 1467.4. Test Program ...................................................................................................... 1487.5. Analogue Input................................................................................................... 1507.6. Simulation Test .................................................................................................. 1517.7. Hardware Test .................................................................................................... 1527.8. Other PIC Demo Kits ........................................................................................ 1537.9. In-Circuit Debugging ......................................................................................... 1557.10. In-Circuit Emulation .......................................................................................... 157

Part 3 PIC Applications

Chapter 8: Application Design......................................................................... 161

8.1. Design Specification .......................................................................................... 1638.2. Hardware Design................................................................................................ 1658.3. Software Design................................................................................................. 1678.4. Program Implementation ................................................................................... 174

Chapter 9: Program Debugging ....................................................................... 181

9.1. Syntax Errors...................................................................................................... 1829.2. Logical Errors .................................................................................................... 1849.3. Test Schedule ..................................................................................................... 1919.4. Interactive Debugging........................................................................................ 1949.5. Hardware Testing ............................................................................................... 198

vi Contents

Chapter 10: Hardware Prototyping.................................................................. 201

10.1. Hardware Design................................................................................................ 20210.2. Hardware Construction ...................................................................................... 20310.3. Dizi84 Board Design ......................................................................................... 21110.4. Dizi84 Applications ........................................................................................... 213

Chapter 11: PIC Motor Applications................................................................ 233

11.1. Motor Control Methods ..................................................................................... 23411.2. Motor Application Board MOT2....................................................................... 23611.3. Motor Control Methods ..................................................................................... 23911.4. Test Programs for MOT2................................................................................... 24111.5. Closed Loop Speed Control............................................................................... 24311.6. Motor Control Modules ..................................................................................... 253

Part 4 Microcontroller Systems

Chapter 12: More PIC Microcontrollers ........................................................... 261

12.1. Common Features .............................................................................................. 26212.2. Device Selection ................................................................................................ 26812.3. Peripheral Interfaces .......................................................................................... 27512.4. Serial Ports ......................................................................................................... 278

Chapter 13: More PIC Applications ................................................................. 285

13.1. TEMCON2 Temperature Controller.................................................................. 28613.2. Simplified Temperature Controllers .................................................................. 30313.3. PIC C Programming........................................................................................... 304

Chapter 14: More Control Systems.................................................................. 311

14.1. Other Microcontrollers....................................................................................... 31214.2. Microprocessor Systems .................................................................................... 31514.3. Control Technologies ......................................................................................... 31914.4. Control System Design ...................................................................................... 329

Part 5 Appendices

Appendix A: Binary Numbers.......................................................................... 335

A.1. Number Systems ................................................................................................. 335A.2. Numerical Conversion ........................................................................................ 341A.3. Binary Arithmetic ............................................................................................... 344

Appendix B: Microelectronic Devices ............................................................... 349

B.1. Digital Devices.................................................................................................... 349B.2. Combinational Logic .......................................................................................... 353

Contents vii

B.3. Sequential Logic ................................................................................................. 357B.4. Data Devices ....................................................................................................... 359B.5. Simple Data System............................................................................................ 361B.6. Four-Bit Data System ......................................................................................... 362

Appendix C: Digital Systems........................................................................... 367

C.1. Encoder and Decoder.......................................................................................... 367C.2. Multiplexer, Demultiplexer and Buffer .............................................................. 368C.3. Registers and Memory........................................................................................ 371C.4. Memory Address Decoding................................................................................ 372C.5. Counters and Timers........................................................................................... 373C.6. Serial and Shift Registers ................................................................................... 374C.7. Arithmetic and Logic Unit ................................................................................. 375C.8. Processor Control................................................................................................ 376C.9. CPU System Operation....................................................................................... 376C.10. PIC16 MCU Operation ....................................................................................... 379

Appendix D: Dizi84 Demo Board .................................................................... 381

D.1. Circuit Design ..................................................................................................... 381D.2. Construction and Testing .................................................................................... 383D.3. Analogue Conversion.......................................................................................... 385D.4. EEPROM Storage ............................................................................................... 387D.5. LOCK Application.............................................................................................. 388

Appendix E: Dizi690 Demo Board .................................................................. 397

E.1. Circuit Design ..................................................................................................... 397E.2. Schematic Edit .................................................................................................... 398E.3. Program Edit ....................................................................................................... 401E.4. Circuit Simulation............................................................................................... 402E.5. PCB Design......................................................................................................... 406E.6. Package Assignment ........................................................................................... 407E.7. Layout Edit ......................................................................................................... 409E.8. Output Files......................................................................................................... 411E.9. PCB Fabrication.................................................................................................. 413

Answers to Questions...................................................................................... 417References and Links....................................................................................... 427Demo Files..................................................................................................... 429Index ............................................................................................................. 431

viii Contents

Preface to the 3rd Edition

p0010 The first edition of this book concentrated on a single chip that was widely used in hobby

electronics and education e the PIC� 16F84A. This has now been superseded by chips

that are faster, cheaper, and more complex and powerful. This has created a dilemma e

whether to still use this chip that is effectively obsolete or substitute a current chip that is

more complicated. In the end, I have done both e sticking with the ‘84 due to its relative

simplicity in the initial stages, and then moving on to more recent chips with extra

features, such as the 16F690. At the same time, I have taken advantage of simulation

software that is now available, which provides on-screen animated circuits and user-

friendly microcontroller program debugging.

p0015 All the main points in this book are illustrated by simple examples, which are downloadable

from the support website at www.picmicros.org.uk. Program source code can be modified,

reassembled and retested using Microchip’s MPLAB IDE development system, downloadable

free from www.microchip.com. This website also provides many of the technical references

and data sheets used in the book. The schematic capture and simulation software is from

Labcenter Electronics at www.labcenter.com. A demo version is available, but to create and

test your own applications, a license will be needed. A low-cost package, including a model for

the 16F84A, is currently available.

p0020 The book is aimed at beginners, so more experienced readers should skip over any bits that are

already familiar. Some basic principles have been moved to the appendices in this edition, to

make room for updated applications and examples. Again, these are aimed primarily at learners

at college or university, or independent hobbyists. Nevertheless, I hope that more experienced

readers will find some of the examples useful, and will perhaps see the advantages of some of

techniques described, particularly interactive simulations, which enrich the application

development experience at all levels, and potentially enhance productivity for the professional

electronic design engineer.

Martin BatesSussex, England, February 2011

ix

Introduction to the 3rd Edition

p0010 The microcontroller is now at the heart of many electronic products. Mobile

phones, microwave ovens, digital television, credit cards, the Internet and many other current

technologiesrely on these small, unobtrusive devices to make it all happen.

p0015 This book is an attempt to introduce the beginner to this ubiquitous yet complex technology.

Starting with the standard PC (on the basis that most people are familiar with its operation), the

basic concepts and terminology will be established: microprocessor systems, memory, input

and output and general digital systems ideas. We will then go on to study one of the biggest

selling products the general public has never heard of: the PIC� microcontroller (MCU). It

dominates the market for small-scale industrial applications, with the manufacturer Microchip

Inc. currently reporting annual sales over US $1 billion per annum.

p0020 We will start by studying a chip that is no longer commercially significant, but is relatively

simple, with the minimum of advanced features: the PIC 16F84A. This was one of the first

popular small microcontrollers with flash program memory, the kind found in memory sticks.

This allows it to be easily reprogrammed and therefore made it ideal for learning and hobby

electronics. We will learn how to connect up and program this chip, and design simple

applications, such as flashing output LEDs. In addition, simulation software will be

introduced, which makes the design process easier, and more fun. We will then move on to

the PIC 16F690, which has more features, and is representative of more recent products in the

PIC range. Many microcontrollers used in real applications such as motor vehicle engine

control or communications systems are more powerful, but the operating principles are just

the same. Other types of control technology will be reviewed for comparison with

microcontrollers.

p0025 The book uses numerous examples relating to motor control, because this is a very common

control requirement (used in disk drives, washing machines, conveyors, etc.). The small direct

current motor is inexpensive and can be easily connected to the output of a PIC via a simple

current driver interface. The response of the motor is easily observed, yet can be complex,

which demonstrates the problems associated with real-time system control. The motor also

provides a link to wider areas of engineeringemechatronics, robots, machine tools and

industrial systemsethat is useful for students and engineers in these disciplines.

xi

p0030 The big problem with microprocessors and microcontrollers is that, to fully understand how

they work, we have to understand both the hardware and the software at the same time.

Therefore, we have to we have to circle round the subject, looking at the system from different

angles, until a reasonable level of understanding is built up. The book will cover basic

hardware design, interfacing, program development, debugging, testing and analysis using

a range of simple examples. This is supported by appendices, which introduce basic concepts

to readers who do not have this essential background e number systems, digital principles and

microprocessor system concepts, as well as system design exercises. Appendix E covers the

whole design process using the Proteus VSM electronic design suite.

p0035 There is a summary at the start of each chapter, so that its content can be seen at a glance, as

well as a set of questions at the end for self-assessment or formal testing of students (with full

answers at the end of the book) and suggested activities which can be developed into practical

assessments if required. The style of the book is also intended as a model for students who need

to write technical reports for such practical assessments. The stages of application development

should be clearly identified in this case: specification, design, implementation and testing.

Another useful model can be seen in the application notes written by professional engineers,

such as those available on the Microchip website.

p0040 The content of each chapter is a compromise between maintaining overall continuity and

allowing each chapter to be read independently. There will therefore be a certain amount of

repetition between chapters, which I hope the reader will not find too irritating, and may aid

learning. It is always difficult to decide exactly what to include in this kind of book, where the

subject is vast and complex. My intention is always to keep it simple, and I hope my selection

will help the reader to begin to get to grips with the fascinating world of microcontrollers, and

go on to a reasonable understanding of real applications, progressing perhaps to a career in

microcontroller application design. However, an understanding of microcontrollers is essential

for any electrical engineer, since the technology is now central to most electronic products and

industrial systems.

xii Introduction to the 3rd Edition