FPGA Prototyping by VHDL Examples (2^nd Ed.) Xilinx MicroBlaze MCS SoC

A hands-on introduction to FPGA prototyping and SoC design

This Second Edition of the popular book follows the same ?learning-by-doing? approach to teach the fundamentals and practices of VHDL synthesis and FPGA prototyping. It uses a coherent series of examples to demonstrate the process to develop sophisticated digital circuits and IP (intellectual property) cores, integrate them into an SoC (system on a chip) framework, realize the system on an FPGA prototyping board, and verify the hardware and software operation. The examples start with simple gate-level circuits, progress gradually through the RT (register transfer) level modules, and lead to a functional embedded system with custom I/O peripherals and hardware accelerators. Although it is an introductory text, the examples are developed in a rigorous manner, and the derivations follow strict design guidelines and coding practices used for large, complex digital systems.

The new edition is completely updated. It presents the hardware design in the SoC context and introduces the hardware-software co-design concept. Instead of treating examples as isolated entities, the book integrates them into a single coherent SoC platform that allows readers to explore both hardware and software ?programmability? and develop complex and interesting embedded system projects. The revised edition:

• Adds four general-purpose IP cores, which are multi-channel PWM (pulse width modulation) controller, I²C controller, SPI controller, and XADC (Xilinx analog-to-digital converter) controller.
• Introduces a music synthesizer constructed with a DDFS (direct digital frequency synthesis) module and an ADSR (attack-decay-sustain-release) envelop generator.
• Expands the original video controller into a complete stream-based video subsystem that incorporates a video synchronization circuit, a test pattern generator, an OSD (on-screen display) controller, a sprite generator, and a frame buffer.
• Introduces basic concepts of software-hardware co-design with Xilinx MicroBlaze MCS soft-core processor.
• Provides an overview of bus interconnect and interface circuit.
• Introduces basic embedded system software development.
• Suggests additional modules and peripherals for interesting and challenging projects.

The FPGA Prototyping by VHDL Examples, Second Edition makes a natural companion text for introductory and advanced digital design courses and embedded system course. It also serves as an ideal self-teaching guide for practicing engineers who wish to learn more about this emerging area of interest.

Preface ix

Acknowledgments xv

PART I BASIC  DIGITAL  CIRCUITS DEVELOPMENT

1 Gate-level Combinational Circuit 1

1.1 Overview of VHDL 1

1.2 General description 2

1.3 Structural description 6

1.4 Top-level  signal mapping 8

1.5 Testbench 9

1.6 Bibliographic notes 11

1.7 Suggested experiments 11

2 Overview of FPGA and EDA  software 13

2.1 FPGA 13

2.2 Overview of the Digilent Nexys  4 DDR    board 15

2.3 Development flow 16

2.4 Xilinx  Vivado  Design  Suite 18

2.5 Bibliographic notes 18

2.6 Suggested experiments 18

3 RT-level combinational circuit 23

3.1 RT-level components 23

3.2 Routing circuit with concurrent assignment   statements 29

3.3 Modeling with a  process 34

3.4 Routing circuit with if and case    statements 36

3.5 Constants and generics 41

3.6 Replicated structure 44

3.7 Design examples 46

3.8 Bibliographic notes 58

3.9 Suggested experiments 58

4 Regular Sequential Circuit 61

4.1 Introduction 61

4.2 HDL code of the FF and  register 64

4.3 Simple design examples 67

4.4 Testbench for sequential circuits 72

4.5 Case study 75

4.6 Timing  and clocking 87

4.7 Bibliographic notes 90

4.8 Suggested experiments 90

5 FSM  93

5.1 Introduction 93

5.2 FSM code development 97

5.3 Design examples 100

5.4 Bibliographic notes 110

5.5 Suggested experiments 110

6 FSMD 113

6.1 Introduction 113

6.2 Code development of an FSMD 119

6.3 Design examples 125

6.4 Bibliographic notes 140

6.5 Suggested experiments 141

7 RAM and Buffer of FPGA 145

7.1 Embedded memory of FPGA device 145

7.2 General description for RAM-like   component  147

7.3 FIFO buffer  153

7.4 HDL templates for memory  inference  158

7.5 Overview of memory controller  164

7.6 Bibliographic notes  166

7.7 Suggested experiments  166

PART II EMBEDDED SOC I: VANILLA  FPRO SYSTEM

8 Overview of Embedded SoC Systems 171

8.1 Embedded  SoC 171

8.2 Development Flow of Embedded   SoC 173

8.3 FPro  SoC Platform 176

8.4 Adaption  on  Digilent  Nexys  4  DDR board 180

8.5 Portability 182

8.6 Organization 184

8.7 Bibliographic notes 184

9 Bare Metal System Software Development 187

9.1 Bare metal system development overview 187

9.2 Memory-mapped  I/O 189

9.3 Direct  I/O  Register Access 191

9.4 Robust  I/O  Register Access 193

9.5 Techniques for low-level I/O  operations 197

9.6 Device Drivers 199

9.7 FPro  Utility  Routines  and  Directory Structure 204

9.8 Test program 208

9.9 Bibliographic notes 211

9.10 Suggested experiments 211

10 FPro Bus Protocol and MMIO Slot Specification 213

10.1 FPro Bus 213

10.2 Interface with bus 216

10.3 MMIO I/O core 222

10.4 Timer core development 226

10.5 MMIO controller 229

10.6 MCS I/O bus and bridge 234

10.7 Vanilla FPRO System Construction 238

10.8 Bibliographic notes 240

10.9 Suggested experiments 240

11 UART Core 243

11.1 Introduction 243

11.2 UART Construction 245

11.3 UART core  development 253

11.4 UART driver 256

11.5   Additional  Project Ideas 262

11.6 Bibliographic notes 265

11.7 Suggested experiments 266

PART III EMBEDDED SOC II: BASIC I/O CORES

12 Xilinx XADC Core 271

12.1 Overview of XADC 271

12.2 XADC core development 273

12.3 XADC core device driver 278

12.4 Sampler FPro System 281

12.5 Additional Project Ideas 291

12.6 Bibliographic notes 292

12.7 Suggested experiments 292

13 Pulse Width Modulation Core 295

13.1 Introduction 295

13.2 PWM Design 296

13.3 PWM core development 299

13.4 PWM  driver 302

13.5 Testing 303

13.6 Project ideas 304

13.7 Suggested experiments 305

14 Debouncing  core and LED-Mux  Core 307

14.1 Debouncing Core 307

14.2 LED-Mux   Core 313

14.3 Project  Ideas 319

14.4 Suggested Experiments 320

15 SPI Core 323

15.1 Overview 323

15.3 SPI  Core Development  333

15.4 SPI Driver  336

15.5 Test  338

15.6 Project Ideas  341

15.7 Bibliographic notes  342

15.8 Suggested Experiments  342

16 I2C Core 347

16.1 Overview 347

16.2 I2C Controller 350

16.3 I2C Core Development 360

16.4 I2C  Driver 361

16.5 Test 365

16.6 Project  Idea 366

16.7 Bibliographic notes 367

16.8 Suggested experiments 367

17 PS2 Core 371

17.1 Introduction 371

17.2 PS2 Controller 373

17.3 PS2 core development 383

17.4 PS2 driver 384

17.5 Test 393

17.6 Bibliographic notes 394

17.7 Suggested experiments 394

18 Sound I: DDFS  Core 397

18.1 Introduction 397

18.2 Design and implementation 397

18.3 Fixed-point arithmetic 400

18.4 DDFS Construction 402

18.5 DAC (digital-to-analog converter) 404

18.6 DDFS core development 407

18.7 DDFS driver 409

18.8 Testing 412

18.9 Bibliographic notes 413

18.10 Suggested experiments 413

19 Sound II: ADSR Core 415

19.1 Introduction 415

19.2 ADSR envelope generator 416

19.3 ADSR core development 421

19.4 ADRS driver 423

19.5 Testing 429

19.6 Project  Idea 430

19.7 Bibliographic notes 431

19.8 Suggested experiments 431

PART IV EMBEDDED SOC III: VIDEO  CORES

20 Introduction to Video System 435

20.1 Introduction to a video  display 435

20.2 Stream interface 437

20.3 VGA Synchronization 439

20.4 Bar  test-pattern generator 448

20.5 Color-to-grayscale conversion circuit 449

20.6 Demo video system 451

20.7 Advanced video standards 452

20.8 Bibliographic notes 453

20.9 Suggested experiments 454

21 FPro Video Subsystem 457

21.1 Organization of video subsystem 457

21.2 FPro video IP core 461

21.3 Example video cores 466

21.4 FPro video synchronization core 470

21.5 Daisy video subsystem 479

21.6 Vanilla daisy FPro system 486

21.7 Video driver and testing program 490

21.8 Bibliographic notes 493

21.9 Suggested experiments 493

22 Sprite Core 497

22.1 Introduction 497

22.2 Basic design 498

22.3 Mouse pointer core 500

22.4 “Ghost” character core 505

22.5 Sprite core driver and testing program 513

22.6 Bibliographic notes 516

22.7 Suggested experiments 516

23 On-Screen-Display Core 519

23.1 Introduction to tile graphics 519

23.2 Basic OSD design 521

23.3 OSD core  524

23.4 OSD core driver and testing   program  530

23.5 Bibliographic notes  532

23.6 Suggested experiments  532

24 VGA  Frame  Buffer Core 535

24.1 Overview 535

24.2 Frame buffer core 536

24.3 Register map 540

24.4 Driver and testing program 542 543

24.5 Project Ideas 545

24.6 Bibliographic notes 547

24.7 Suggested experiments 547

PART V EPILOGUE

25  What Next 553

References 557

Appendix A: Tutorials 561

A.1 Overview of Xilinx Vivado  IDE 561

A.2 Short tutorial on Vivado hardware   development 565

A.3 Short tutorial on Vivado   simulation 570

A.4 Tutorial on IP instantiation 574

A.5 Short tutorial on FPro system   development 580

A.6 Bibliographic notes 587

Topic Index 589

PONG P. CHU, PhD is Associate Professor in the Department of Electrical Engineering and Computer Science at Cleveland State University, Cleveland, Ohio. He has taught undergraduate and graduate digital systems and computer architecture courses for more than two decades, and has received multiple instructional grants from the National Science Foundation.