PIC microcontroller: an introduction to software and hardware interfacing

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THOMSON

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DELMAR LEARNING

PIC Microcontroller: An Introduction to Software and Hardware Interfacing

Han-Way Huang

Vice President, Technology

and Trades SBU:

Alar Elken

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Contents

Preface xxj

1.1 Objectives 1

1.2 What Is a Computer? 2

1.2.1 The Processor 2

1.2.2 The Microprocessor 3

1.2.3 Microcontrollers 4

1.2.4 Memory 4

1.3 The Computer Software 6

1.3.1 Assembly Language 6

1.3.2 High-Level Languages 7

1.4 Overview of the PIC18 MCU 8

1.5 The PIC18 Memory Organization 13

1.5.1 Separation of Data Memory and Program Memory 13

1.5.2 PIC18 Data Memory 14

1.5.3 EEPROM Data Memory 15

1.5.4 Program Memory Organization 15

1.6 The PIC18 CPU Registers 17

1.7 The PIC18 Pipelining 19

1.8 PIC18 Instruction Format 20

1.9 Addressing Modes 22

1.9.1 Register Direct 22

1.9.2 Immediate Mode 23

1.9.3 Inherent Mode 23

1.9.4 Indirect Mode 23

1.9.5 Bit-Direct Addressing Mode 25

1.10 A Sample of PIC18 Instructions 26

1.10.1 Data Movement Instructions 26

1.10.2 ADD Instructions 27

1.10.3 SUB Instructions 29

Contents

1.11 Overview of the 8-Bit MCU Market 29

1.1 1.1 CISC versus RISC 30

1.1 1.2 Major 8-Bit MCUs 31

1.11.3 Motorola 8-Bit MCUs 32

1.11.4 Intel 805 118052 Variants 32

1.1 1.5 The Atmel AVR 33

1.12 Summary 33

1.13 Exercises 35

Chapter 2 PIC18 Assembly Language Programming 37

Objectives 37

Introduction 38

Assembly Language Program Structure 38

2.3.1 The Label Fields 38

2.3.2 The Mnemonic Field 39

2.3.3 The Operand Field 39

2.3.4 The Comment Field 39

Assembler Directives 40

2.4.1 Control Directives 40

2.4.2 Data Directives 44

2.4.3 Macro Directives 47

2.4.4 Listing Directives 48

2.4.5 Object File Directives 50

Representing the Program Logic 53

A Template for Writing Assembly Programs 55

Case Issue 56

Writing Programs to Perform Arithmetic Computations 56

2.8.1 Perform Addition Operations 56

2.8.2 Perform Subtraction Operations 58

2.8.3 Binary Coded Decimal Addition 60

2.8.4 Multiplication 63

Program Loops 66

2.9.1 Program Loop Constructs 66

2.9.2 Changing the Program Counter 68

Reading and Writing Data in Program Memory 75

Logic lnstructions 78

Using Program Loop to Create Time Delays 80

Rotate lnstructions 82

Using Rotate lnstructions to Perform Multiplications and Divisions 85

Summary 86

Exercises 87

Contents vii

Chapter 3 PIC18 Development Tools 89

3.1 Objectives 89

3.2 Development Tools 90

3.3 Software Tools 90

3.3.1 Text Editors 90

3.3.2 Cross Assemblers and Cross Compilers 90

3.3.3 Simulator 90

3.3.4 Source-Level Debugger 91

3.3.5 Integrated Development Environment 9 1

3.4 Hardware Tools 91

3.4.1 The Nature of Debugging Activities 91

3.4.2 ICE 92

3.4.3 Device Programmer 93

3.4.4 In-Circuit-Debugger I1 94

3.4.5 Demo Boards 95

3.5 Using MPLAB IDE 95

3.5.1 Getting Started with MPLAB IDE 96

3.5.2 Creating a Simple Project 97

3.5.3 Entering Source Code 100

3.5.4 Adding Source Files to the Project 101

3.5.5 Building the Project 102

3.5.6 Debugging the Project 102

3.6 Using the MPLAB SIM in Debugging PIC18 Applications 102

3.6.1 Setting Up the Simulator 103

3.6.2 Running Code under MPLAB SIM 103

3.6.3 Viewing Variables 105

3.6.4 Using Watch Window to View Variables 105

3.6.5 Setting Breakpoints 106

3.6.6 Tracing Code 108

3.6.7 Advanced Simulator Options 1 10

3.7 Using the MPLAB ICD 2 111

3.7.1 ICD2 Settings 112

3.8 Demo Boards from ShuanShizu Enterprise 116

3.8.1 SSE452 Demo Board 116

3.8.2 SSE8720DemoBoard 118

3.8.3 SSE8680 Demo Board 119

3.8.4 Debug Monitor 120

3.9 Summary 120

3.10 Lab Exercises and Assignments 121

viii Contents

Chapter 4 Advanced Assembly Programming 125

Objectives 125

lntroduction 126

Signed Arithmetic 126

4.3.1 Signed 8-Bit Multiplication 126

4.3.2 Signed 16-Bit Multiplication 128

Unsigned Divide Operation 131

Signed Divide Operation 133

The Stack 137

4.6.1 Staclz Operations 138

Subroutines 139

4.7.1 Instructions for Supporting Subroutine Calls 140

4.7.2 Return Address Stack 141

4.7.3 Top-of-Stack Access 141

4.7.4 Return Address Stack Pointer (STKPTR) 141

4.7.5 Fast Register Stack 141

4.7.6 Table Lookup Instruction 142

Issues Related to Subroutine Calls 142

4.8.1 The Stack Frame 144

4.8.2 Accessing Locations in the Staclz Frame 144

String Processing 153

More Examples on Subroutine Calls 166

4.10.1 Square Root Computation 171

4.10.2 Finding Prime Numbers 174

Summary 177

Exercises 177

Lab Exercises and Assignments 179

Chapter 5 A Tutorial to the C Language and the Use

of the C Compiler 183

5.1 Objectives 183

5.2 Introduction to C lS4

5.3 Types, Operators, and Expressions 185

5.3.1 Data Types 185

5.3.2 Variable Declarations 185

5.3.3 Constants 185

5.3.4 Arithmetic Operators 186

5.3.5 Bitwise Operators 186

5.3.6 Relational and Logical Operators 187

5.3.7 Precedence of Operators 188

5.4 Control Flow 188

5.4.1 If Statement 188

Contents

5.4.2 If-Else Statement 189

5.4.3 Multiway Conditional Statement 189

5.4.4 Switch Statement 190

5.4.5 For-Loop Statement 190

5.4.6 While Statement 191

5.4.7 Do-While Statement 191

5.4.8 GOT0 Statement 191

Input and Output 192

Functions and Program Structure 193

Pointers, Arrays, Structures, and Unions 196

5.7.1 Pointers and Addresses 196

5.7.2 Arrays 197

5.7.3 Pointers and Arrays 197

5.7.4 Passing Arrays to a Function 198

5.7.5 Initializing Arrays 199

5.7.6 Structures 199

5.7.7 Unions 200

Miscellaneous Items 201

5.8.1 Automatic/External/Static/Volatile 201

5.8.2 Scope Rules 202

Introduction to Project Build Process for the Microchip PIC18 Compiler 203

The MPLINK Linker 204

A Tutorial on Using the MCC18 Compiler 209

5.11.1 CreatingaNewProject 210

5.1 1.2 Setting Build Options 212

5.1 1.3 Add Source Files to Project 212

5.1 1.4 Building the Project 214

5.11.5 Choosing Debug Tool 214

5.11.6 Buildtheproject 214

5.11.7 Checking the ICD2 Settings 214

5.11.8 Program the Target Device 215

5.1 1.9 Running the Program 215

C Language Implementation in the MCC18 Compiler 216

5.12.1 Data Types and Limits 216

5.12.2 Storage Classes 217

5.12.3 Storage Qualifiers 218

5.12.4 Overlay 218

ANSI/ISO Divergences 219

5.13.1 Integer Promotions 219

5.13.2 Numeric Constants 220

5.13.3 String Constants 220

5.13.4 Anonymous Structures 221

lnline Assembly 221

Bit Field Manipulation in C Language 222

Contents

5.15.1 Processor-Specific Header Files 223

5.15.2 Processor-Specific Register Definition Files 225

5.16 The #pragma Statement 225

5.16.1 #pragma Section Type 225

5.17 Mixing C and Assembly 226

5.17.1 Calling Conventions 226

5.17.2 Return Values 228

5.17.3 Calling C Routines from an Assembly Program 228

5.17.4 Calling Assembly Functions from a C Program 229

5.17.5 Referencing C Variables in an Assembly Function 230

5.17.6 Referencing Assembly Variables in a C Function 23 1

5.17.7 Startup Code 231

5.18 MPLAB C18 Library Functions 232

5.18.1 Processor-Specific Libraries 232

5.18.2 Processor-Independent Library 232

5.18.3 Character Classification Functions 232

5.18.4 Data Conversion Library Functions 233

5.18.5 Memory and String Manipulation Functions 234

5.18.6 Delay Functions 235

5.19 Using the Hi-Tech C18 Compiler 237

5.20 Summary 238

5.21 Exercises 239

5.22 Lab Exercises and Assignments 240

Chapter 6 Interrupts, Resets, and Configuration 243

6.1 Objectives 243

6.2 Basics of lnterrupts 244

6.2.1 What Is an Interrupt? 244

6.2.2 Why Interrupts? 245

6.2.3 Interrupt Maskability 245

6.2.4 Interrupt Priority 246

6.2.5 Interrupt Service 246

6.2.6 Interrupt Vector 246

6.2.7 Interrupt Programming 247

6.2.8 Interrupt Overhead 248

6.3 Resets 248

6.4 The PIC18 lnterrupts 249

6.4.1 PIC18 Interrupt Priority 249

6.4.2 Registers Related to Interrupts 249

6.4.3 RCON Register 249

6.4.4 Interrupt Control Registers (INTCON, INTCON2, INTCON3) 250

6.4.5 PIR1 . . . PIR3 Registers 253

Contents

6.4.6 PIE1 . . . PIE3 Registers 255

6.4.7 Interrupt Priority Registers (IPR1 . . . IPR3) 258

6.5 PIC18 Interrupt Operation 261

6.5.1 PIC18 Interrupt without Setting Priority 262

6.5.2 PIC18 Interrupt with Priority Enabled 262

6.5.3 INT Pin Interrupts 263

6.5.4 Port B Pins Input Change 263

6.5.5 TMRO Overflow Interrupt 263

6.5.6 Peripheral Interrupts 263

6.6 PIC18 Interrupt Programming 264

6.6.1 Interrupt Programming in Assembly Language 264

6.6.2 Interrupt Programming in C Language 267

6.6.3 Context Saving during Interrupts 269

6.7 The PIC18 Resets 270

6.7.1 Power-On Reset 271

6.7.2 Power-Up Timer 271

6.7.3 Oscillator Start-Up Timer 271

6.7.4 Brown-Out Reset 271

6.7.5 The Reset Instruction 271

6.8 Summary 271

6.9 Exercises 273

6.10 Lab Exercises and Assignments 273

Chapter 7 Parallel Ports 275

7.1 Objectives 275

7.2 Introduction 276

7.3 1/O Addressing 277

7.4 1/O Synchronization 277

7.4.1 Synchronizing the CPU with the Interface Chip 278

7.4.2 Synchronizing the Interface Chip with 110 Devices 279

7.5 Overview of the PIC18 Parallel Ports 281

7.5.1 Port A 283

7.5.2 Port B 284

7.5.3 Port C 285

7.5.4 Port D 285

7.5.5 Port E and Port F 286

7.5.6 Port G 286

7.5.7 Port H and Port J 286

7.5.8 Port K 287

7.6 Interfacing with Simple Output Devices 287

7.6.1 Interfacing with LEDs 287

7.6.2 Interfacing with Seven-Segment Displays 288

7.6.3 Liquid Crystal Display 293

7.7 The HD44780 LCD Controller 294

7.7.1 Display Data RAM 296

7.7.2 Character Generator ROM 297

7.7.3 Character Generator RAM 297

7.7.4 Registers 297

7.7.5 Instruction Description 298

7.7.6 Interfacing the HD44780 to the PIC18 Microcontroller 299

7.8 Interfacing with DIP Switches 312

7.9 lnterfacing with a Keypad 313

7.9.1 Keypad Scanning 3 13

7.9.2 Keypad Debouncing 3 14

7.10 lnterfacing with a D/A Converter 322

7.10.1 The MAX5 102 DAC 322

7.10.2 Interfacing the MAX5102 with the PIC18 Microcontroller 324

7.11 Parallel Slave Port 326

7.12 Summary 330

7.13 Exercises 330

7.14 Lab Exercises and Assignments 332

Chapter 8 Timers and CCP Modules 333

8.1 Objectives 333

8.2 Overview of PIC18 Timer Functions 334

8.3 Timers 334

8.3.1 Timer0 335

8.3.2 Timer1 338

8.3.3 Timer2 343

8.3.4 Timer3 345

8.3.5 Timer4 346

8.3.6 C Library Functions for Timers 347

8.4 Capture/Compare/PWM Modules 349

8.4.1 CCP Module Configuration 350

8.5 CCP in Capture Mode 351

8.5.1 Capture Operation 352

8.5.2 Microchip C Library Functions for CCP in Capture Mode 352

8.5.3 Applications of Capture Mode 353

8.6 CCP in Compare Mode 361

8.6.1 Compare Mode Operation 361

8.6.2 Applications of CCP in Compare Mode 362

8.7 CCP in PWM Mode 373

8.7.1 PWM C Library Functions 376

8.7.2 PWM Applications 377

8.7.3 DC Motor Control 380

Contents

8.8 Enhanced CCP Module 385

8.8.1 ECCPPins 385

8.8.2 ECCP Registers 385

8.8.3 Enhanced PWM Mode 387

8.9 Summary 401

8.10 Exercises 403

8.11 Lab Exercises and Assignments 404

Chapter 9 Addressable Uniyersal Synchronous Asynchronous Receiver Transceiver 407

Objectives 407

Overview of Serial Communication 408

The EIA232 Standard 408

9.3.1 Electrical Specifications 409

9.3.2 EIA232E Functional Specifications 409

9.3.3 EIA232E Mechanical Specifications 412

9.3.4 EIA232E Procedural Specifications 413

9.3.5 Data Format 416

9.3.6 Data Transmission Errors 41 7

9.3.7 Null-Modem Connection 41 7

The PIC18 Serial Communication Interface 418

9.4.1 USART-Related Registers 418

9.4.2 USART Asynchronous Mode 421

9.4.3 Flow Control of USART in Asynchronous Mode 426

9.4.4 C Library Functions for USART 427

9.4.5 Interface Asynchronous Mode USART with EIA232 430

9.4.6 USART Synchronous Master Mode 432

9.4.7 USART Synchronous Slave Mode 434

9.4.8 Applications of USART Synchronous Mode 434

Enhanced USART 440

Summary 441

Exercises 442

Lab Exercises and Assignments 443

Chapter 10 Serial Peripheral Interface 445

10.1 Objectives 445

10.2 Introduction 446

10.3 SPl Mode 446

10.3.1 MSSP Registers 447

10.3.2 SPI Operation 449

Contents

10.3.3 Configuration of MSSP for SPI Mode 449

10.3.4 SPI Data Transfer 453

10.3.5 SPI Circuit Connection 453

SPI C Library Functions 455

Applications of SPI 456

Interfacing with the 74HC595 456

10.6.1 Operation of the 74HC595 457

MAX7221 Seven-Segment Display Driver 462

10.7.1 Signal Pins 462

10.7.2 MAX7221 Functioning 463

10.7.3 Choosing the Value for RsET 468

Digital Temperature Sensor TC72 474

10.8.1 Functioning of TC72 475

10.8.2 Temperature Data Format 475

10.8.3 Serial Bus Interface 476

10.8.4 Internal Register Structure 478

The DS1306 Alarm Real-Time Clock 481

10.9.1 Signal Descriptions 482

10.9.2 RTC Registers 483

10.9.3 Serial Interface of DS1306 487

10.9.4 Power Supply Configurations 488

10.9.5 Applications 488

Summary 498

Exercises 499

Lab Exercises and Assignments 502

Chapter 11 Interintegrated Circuit Interface 503

11.1 Objectives 503

11.2 The I2C Protocol 504

11.2.1 Characteristics of 12C Protocol 504

1 1.2.2 12C Signal Levels 504

11.2.3 12C Data Transfer Signal Components 505

11.2.4 Synchronization 507

11.2.5 Arbitration 508

11.2.6 Data Transfer Format 509

11.2.7 7-Bit Addressing 5 10

11.2.8 10-Bit Addressing 5 12

11.3 PIC18 MSSP Module in I2C Mode 515

11.4 Registers for I2C Operation 515

11.4.1 The SSPCONl Register 515

11.4.2 The SSPCON2 Register 516

11.4.3 The SSPSTAT Register (12C Mode) 5 18

1 1.4.4 MSSP Address Register 5 19