A hands-on introduction to FPGA prototyping and SoC design
This is the successor edition of the popular FPGA Prototyping by Verilog Examples text. It follows the same “learning-by-doing” approach to teach the fundamentals and practices of HDL synthesis and FPGA prototyping. The new edition 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 the strict design guidelines and coding practices used for large, complex digital systems.
The book is completely updated and uses the SystemVerilog language, which “absorbs” the Verilog language. 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 new 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) envelope 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.
- Provides a detailed discussion on blocking and nonblocking statements and coding styles.
- Describes basic concepts of software-hardware co-design with Xilinx MicroBlaze MCS soft-core processor.
- Provides an overview of bus interconnect and interface circuit.
- Presents basic embedded system software development.
- Suggests additional modules and peripherals for interesting and challenging projects.
FPGA Prototyping by SystemVerilog Examples makes a natural companion text for introductory and advanced digital design courses and embedded system courses. It also serves as an ideal self-teaching guide for practicing engineers who wish to learn more about this emerging area of interest.
Table of Contents
Preface xxvii
Acknowledgments xxxiii
PART I BASIC DIGITAL CIRCUITS DEVELOPMENT
1 Gate-Level Combinational Circuit 1
1.1 Introduction 1
1.1.1 Brief history of Verilog and SystemVerilog 1
1.1.2 Book coverage 2
1.2 General description 3
1.3 Basic lexical elements and data types 4
1.3.1 Lexical elements 4
1.3.2 Data types used in the book 5
1.3.3 Number representation 6
1.3.4 Operators 7
1.4 Program skeleton 7
1.4.1 Port declaration 7
1.4.2 Signal declaration 8
1.4.3 Program body 8
1.4.4 Concurrent semantics 9
1.4.5 Another example 10
1.5 Structural description 10
1.6 Top-level signal mapping 13
1.7 Testbench 14
1.8 Bibliographic notes 16
1.9 Suggested experiments 16
1.9.1 Code for gate-level greater-than circuit 17
1.9.2 Code for gate-level binary decoder 17
2 Overview of FPGA and EDA Software 19
2.1 FPGA 19
2.1.1 Overview of a general FPGA device 19
2.1.2 Overview of the Xilinx Artix-7 devices 20
2.2 Overview of the Digilent Nexys 4 DDR board 21
2.3 Development flow 22
2.4 Xilinx Vivado Design Suite 24
2.5 Bibliographic notes 24
2.6 Suggested experiments 24
2.6.1 Gate-level greater-than circuit 24
2.6.2 Gate-level binary decoder 26
3 RT-Level Combinational Circuit 29
3.1 Operators 29
3.1.1 Arithmetic operators 31
3.1.2 Shift operators 31
3.1.3 Relational and equality operators 32
3.1.4 Bitwise, reduction, and logical operators 32
3.1.5 Concatenation and replication operators 33
3.1.6 Conditional operators 34
3.1.7 Operator precedence 35
3.1.8 Expression bit-length adjustment 35
3.1.9 Synthesis of z and x values 36
3.2 Always block for a combinational circuit 38
3.2.1 Overview of always block 39
3.2.2 Procedural assignment 40
3.2.3 Conceptual examples 40
3.3 Coding guidelines 43
3.4 If statement 43
3.4.1 Syntax 43
3.4.2 Examples 44
3.5 Case statement 45
3.5.1 Syntax 45
3.5.2 Examples 46
3.5.3 The casez and casex statements 47
3.5.4 Full case and parallel case 48
3.6 Routing structure of conditional control constructs 49
3.6.1 Priority routing network 49
3.6.2 Multiplexing network 51
3.7 Additional coding guidelines for an always block 52
3.7.1 Common errors in combinational circuit codes 52
3.7.2 Guidelines 56
3.8 Parameter and constant 56
3.8.1 Constant 56
3.8.2 Parameter 58
3.9 Replicated structure 59
3.9.1 Generate-for statement 59
3.9.2 Procedural-for statement 60
3.9.3 Example 60
3.10 Design examples 62
3.10.1 Hexadecimal digit to seven-segment LED decoder 62
3.10.2 Sign-magnitude adder 65
3.10.3 Barrel shifter 68
3.10.4 Simplified floating-point adder 69
3.11 Bibliographic notes 73
3.12 Suggested experiments 73
3.12.1 Multi-function barrel shifter 73
3.12.2 Parameterized barrel shifter 74
3.12.3 Dual-priority encoder 74
3.12.4 BCD incrementor 74
3.12.5 Floating-point greater-than circuit 74
3.12.6 Floating-point and signed integer conversion circuit 74
3.12.7 Enhanced floating-point adder 75
4 Regular Sequential Circuit 77
4.1 Introduction 77
4.1.1 D FF and register 78
4.1.2 Basic block system 78
4.1.3 Code development 79
4.1.4 Sequential circuit coding guidelines and style 79
4.2 HDL code of the FF and register 80
4.2.1 D FF 80
4.2.2 Register 85
4.3 Simple design examples 85
4.3.1 Shift register 85
4.3.2 Binary counter and variant 87
4.4 Testbench for sequential circuits 89
4.5 Case study 93
4.5.1 LED time-multiplexing circuit 93
4.5.2 Stopwatch 101
4.6 Timing and clocking 104
4.6.1 Timing of FF 104
4.6.2 Maximum operating frequency 104
4.6.3 Clock tree 107
4.6.4 GALS system and CDC 107
4.7 Bibliographic notes 108
4.8 Suggested experiments 108
4.8.1 Programmable square wave generator 108
4.8.2 PWM and LED dimmer 108
4.8.3 Rotating square circuit 109
4.8.4 Heartbeat circuit 109
4.8.5 Rotating LED banner circuit 109
4.8.6 Enhanced stopwatch 110
5 FSM 111
5.1 Introduction 111
5.1.1 Mealy and Moore outputs 112
5.1.2 FSM representation 112
5.2 FSM code development 115
5.2.1 Enumerated data type and state assignment 115
5.2.2 Multi-segment code 116
5.2.3 Two-segment code 117
5.3 Design examples 118
5.3.1 Rising-edge detector 118
5.3.2 Debouncing circuit 123
5.3.3 Testing circuit 126
5.4 Bibliographic notes 128
5.5 Suggested experiments 128
5.5.1 Dual-edge detector 128
5.5.2 Early detection debouncing circuit 128
5.5.3 Parking lot occupancy counter 129
6 FSMD 131
6.1 Introduction 131
6.1.1 Single RT operation 132
6.1.2 ASMD chart 132
6.1.3 Decision box with a register 134
6.2 Code development of an FSMD 137
6.2.1 Debouncing circuit based on RT methodology 137
6.2.2 Code with explicit data path components 137
6.2.3 Code with implicit data path components 140
6.2.4 Comparison 142
6.3 Design examples 144
6.3.1 Fibonacci number circuit 144
6.3.2 Division circuit 147
6.3.3 Binary-to-BCD conversion circuit 150
6.3.4 Period counter 153
6.3.5 Accurate low-frequency counter 156
6.4 Bibliographic notes 159
6.5 Suggested experiments 159
6.5.1 Early detection debouncing circuit 159
6.5.2 BCD-to-binary conversion circuit 160
6.5.3 Fibonacci circuit with BCD I/O: design approach 1 160
6.5.4 Fibonacci circuit with BCD I/O: design approach 2 160
6.5.5 Auto-scaled low-frequency counter 161
6.5.6 Reaction timer 161
6.5.7 Babbage difference engine emulation circuit 162
7 RAM and Buffer of FPGA 165
7.1 Embedded memory of FPGA device 165
7.1.1 Memory of an Artix device 166
7.1.2 Memory available in the Nexys 4 DDR board 166
7.2 General description for a RAM-like component 167
7.2.1 Register file 167
7.2.2 Dynamic array indexing operation 169
7.2.3 Key aspects of a RAM module 170
7.2.4 Genuine ROM 171
7.3 FIFO buffer 173
7.3.1 FIFO read configuration 174
7.3.2 Circular queue implementation 175
7.4 HDL templates for memory inference 178
7.4.1 Methods to incorporate memory modules 178
7.4.2 Synchronous dual-port RAM 179
7.4.3 “Simple” synchronous dual-port RAM 180
7.4.4 Synchronous single-port RAM 181
7.4.5 Synchronous ROM 182
7.4.6 BRAM-based FIFO buffer 183
7.4.7 Design considerations 183
7.5 Overview of memory controller 184
7.6 Bibliographic notes 185
7.7 Suggested experiments 186
7.7.1 ROM-based sign-magnitude adder 186
7.7.2 ROM-based temperature conversion 186
7.7.3 FIFO with data width conversion 186
7.7.4 Standard FIFO to FWFT FIFO conversion circuit 187
7.7.5 FIFO buffer with extended status 187
7.7.6 Stack 187
8 Selected Topics of SystemVerilog 189
8.1 Timing model 189
8.1.1 Concurrent constructs 190
8.1.2 Assignment statement 190
8.1.3 Basic model 190
8.1.4 Blocking versus nonblocking assignment 192
8.2 Coding guidelines revisited 194
8.2.1 “Single variable assignment” guideline 195
8.2.2 “Blocking assignment for combinational circuit” guideline 195
8.2.3 “Nonblocking assignment for register” guideline 197
8.3 Alternative coding style 198
8.3.1 First coding style revisited 198
8.3.2 Sequential circuit with mixed blocking and nonblocking assignments 199
8.3.3 Combined coding style 201
8.3.4 Summary 206
8.4 Data types 206
8.4.1 The net and variable types 206
8.4.2 The logic data type 207
8.4.3 Limitation of the logic data type 208
8.4.4 New data types in SystemVerilog 208
8.5 Use of the signed data type 209
8.5.1 Overview 209
8.5.2 Signed number conversion 210
8.6 Bibliographic notes 211
8.7 Suggested experiments 211
8.7.1 Shift register with blocking and nonblocking assignments 211
8.7.2 Alternative coding style for the BCD counter 212
8.7.3 Alternative coding style for the FIFO buffer 212
8.7.4 Alternative coding style for the Fibonacci circuit 212
8.7.5 Dual-mode comparator 212
PART II EMBEDDED SOC I: VANILLA FPRO SYSTEM
9 Overview of Embedded SoC Systems 215
9.1 Embedded SoC 215
9.1.1 Overview of embedded systems 215
9.1.2 FPGA-based SoC 216
9.1.3 IP cores 216
9.2 Development flow of the embedded SoC 217
9.2.1 Hardware–software partition 217
9.2.2 Hardware development flow 217
9.2.3 Software development flow 219
9.2.4 Physical implementation and test 219
9.2.5 Custom IP core development 219
9.3 FPro SoC Platform 220
9.3.1 Motivations 220
9.3.2 Platform hardware organization 221
9.3.3 Platform software organization 223
9.3.4 Modified development flow 224
9.4 Adaptation on the Digilent Nexys 4 DDR board 224
9.5 Portability 226
9.5.1 Processor Module and Bridge 226
9.5.2 MMIO subsystem 227
9.5.3 Video subsystem 227
9.6 Organization 228
9.7 Bibliographic notes 228
10 Bare Metal System Software Development 231
10.1 Bare metal system development overview 231
10.1.1 Desktop-like system versus bare metal system 231
10.1.2 Basic embedded program architecture 232
10.2 Memory-mapped I/O 233
10.2.1 Overview 233
10.2.2 Memory alignment 234
10.2.3 I/O register map 234
10.2.4 I/O address space of the FPro system 234
10.3 Direct I/O Register Access 235
10.3.1 Review of C pointer 235
10.3.2 C pointer for I/O register 236
10.4 Robust I/O register access 237
10.4.1 chu_io_map.h and chu_io_map.svh 237
10.4.2 inttypes.h 238
10.4.3 chu_io_rw.h 239
10.5 Techniques for low-level I/O operations 241
10.5.1 Bit manipulation 241
10.5.2 Packing and unpacking 242
10.6 Device Drivers 243
10.6.1 Overview 243
10.6.2 GPO and GPI drivers 243
10.6.3 Timer driver 245
10.6.4 UART driver 247
10.7 FPro utility routines and directory structure 248
10.7.1 Minimal hardware requirements 248
10.7.2 Utility routines 248
10.7.3 Directory structure 251
10.8 Test program 252
10.8.1 IP core verification routine 252
10.8.2 Programming with limited memory 252
10.8.3 Test function integration 252
10.8.4 Test program for the vanilla FPro system 253
10.8.5 Implementation 254
10.9 Bibliographic notes 255
10.10 Suggested experiments 255
10.10.1 Chasing LEDs 255
10.10.2 Collision LEDs 256
10.10.3 Pulse width modulation 256
10.10.4 System time display 256
11 FPro Bus Protocol and MMIO Slot Specification 257
11.1 FPro bus 257
11.1.1 Overview of the bus 257
11.1.2 SoC interconnect 258
11.1.3 FPro bus protocol specification 259
11.2 Interface with the bus 260
11.2.1 Introduction 260
11.2.2 Write interface and decoding 261
11.2.3 Read interface and multiplexing 263
11.2.4 FIFO buffer as an I/O register 264
11.2.5 Timing consideration 265
11.3 MMIO I/O core 266
11.3.1 MMIO slot interface specification 266
11.3.2 Basic MMIO I/O core construction 268
11.3.3 GPO and GPI cores 269
11.4 Timer core development 270
11.4.1 Custom logic 270
11.4.2 Register map 271
11.4.3 Wrapping circuit for the slot interface 271
11.5 MMIO controller 272
11.5.1 chu_io_map.svh file 273
11.5.2 HDL code 273
11.5.3 Vanilla MMIO subsystem 275
11.6 MCS I/O bus and bridge 278
11.6.1 Overview of Xilinx MicroBlaze MCS 278
11.6.2 MicroBlaze MCS I/O bus 278
11.6.3 MCS-to-FPro bridge 279
11.7 Vanilla FPro system construction 281
11.8 Bibliographic notes 282
11.9 Suggested experiments 283
11.9.1 FPro bus with a byte-lane enable signal 283
11.9.2 Seven-segment control with a GPO core 283
11.9.3 GPIO core 283
11.9.4 Blinking-LED core 284
11.9.5 Timer core with a programmable period 284
11.9.6 Timer core with a run-once mode 284
12 UART Core 287
12.1 Introduction 287
12.1.1 Overview of serial communication 287
12.1.2 Overview of the UART 288
12.1.3 Oversampling procedure 288
12.2 UART construction 289
12.2.1 Conceptual design 289
12.2.2 Baud rate generator 290
12.2.3 UART receiver 291
12.2.4 UART transmitter 293
12.2.5 Top-level HDL code 295
12.3 UART core development 296
12.3.1 Register map 296
12.3.2 Wrapping circuit for the slot interface 297
12.4 UART driver 298
12.4.1 Class definition 299
12.4.2 Basic methods 300
12.4.3 ASCII code 301
12.4.4 Display methods 303
12.4.5 Test 305
12.5 Additional project ideas 305
12.5.1 Original serial port 305
12.5.2 Emulated serial port 305
12.5.3 Direct connection 306
12.5.4 USB-to-UART adaptor 306
12.5.5 Wireless adaptor 307
12.6 Bibliographic notes 308
12.7 Suggested experiments 308
12.7.1 UART-controlled chasing LEDs 308
12.7.2 Alternative read configuration 308
12.7.3 UART controller with a parity bit 308
12.7.4 UART core with an error status 309
12.7.5 Configurable UART core 309
12.7.6 UART core with automatic baud rate detection 309
12.7.7 UART core with enhanced automatic baud rate detection 310
12.7.8 UART core with an automatic baud rate and a parity detection circuit 310
PART III EMBEDDED SOC II: BASIC I/O CORES
13 Xilinx XADC Core 313
13.1 Overview of XADC 313
13.1.1 Block diagram 313
13.1.2 Configuration 314
13.2 XADC core development 315
13.2.1 XADC instantiation 315
13.2.2 Basic wrapping circuit design 316
13.2.3 Register map 318
13.2.4 HDL code 318
13.3 XADC core device driver 320
13.3.1 Class definition 320
13.3.2 Class implementation 321
13.3.3 Testing for the XADC core 322
13.4 Sampler FPro system 323
13.4.1 Testing procedure of an FPro core 323
13.4.2 System configuration 323
13.4.3 Hardware derivation 324
13.4.4 Software verification program 331
13.5 Additional project ideas 332
13.6 Bibliographic notes 333
13.7 Suggested experiments 333
13.7.1 Real-time voltage display 333
13.7.2 Potentiometer-controlled chasing LEDs 333
13.7.3 Potentiometer-controlled LED dimmer 333
13.7.4 Enhanced wrapping circuit: part I 333
13.7.5 Enhanced wrapping circuit: part II 333
14 Pulse Width Modulation Core 335
14.1 Introduction 335
14.1.1 PWM as analog output 335
14.1.2 Main characteristics 336
14.2 PWM design 336
14.2.1 Basic design 336
14.2.2 Enhanced design 337
14.3 PWM core development 339
14.3.1 Register map 339
14.3.2 Wrapped PWM circuit 340
14.4 PWM driver 341
14.4.1 Class definition 341
14.4.2 Class implementation 342
14.5 Testing 343
14.6 Project ideas 343
14.7 Suggested experiments 345
14.7.1 Police dash light 345
14.7.2 Rainbow night light 345
14.7.3 Enhanced PWM core: part I 345
14.7.4 Enhanced PWM core: part II 346
14.7.5 Enhanced GPIO core 346
14.7.6 Servo motor driver 346
15 Debouncing Core and LED-Mux Core 347
15.1 Debouncing Core 347
15.1.1 Multi-bit debouncing circuit 347
15.1.2 Register map and the slot wrapping circuit 350
15.1.3 Driver 351
15.1.4 Test 352
15.2 LED-mux core 352
15.2.1 Eight-digit seven-segment LED display multiplexing circuit 352
15.2.2 Register map and the slot wrapping circuit 354
15.2.3 Driver 355
15.2.4 Test 358
15.3 Project ideas 358
15.4 Suggested experiments 360
15.4.1 Area comparison of two debouncing circuits 360
15.4.2 Enhanced debouncing core: part I 360
15.4.3 Enhanced debouncing core: part II 360
15.4.4 Rotating square pattern revisited 360
15.4.5 Heartbeat pattern revisited 360
15.4.6 Stopwatch 360
15.4.7 Enhanced LED-mux core 361
16 SPI Core 363
16.1 Overview 363
16.1.1 Conceptual architecture 364
16.1.2 Multiple-device configuration 364
16.1.3 Basic timing 366
16.1.4 Operation modes 367
16.1.5 Undefined aspects 368
16.2 SPI controller 369
16.2.1 Basic design 369
16.2.2 FSMD construction 370
16.2.3 HDL implementation 370
16.3 SPI core development 374
16.3.1 Register map 374
16.3.2 Wrapping circuit for the slot interface 374
16.4 SPI driver 376
16.4.1 Class definition 376
16.4.2 Class implementation 377
16.5 Test 378
16.5.1 ADXL362 accelerometer 378
16.5.2 Test program 380
16.6 Project ideas 381
16.6.1 SD card 381
16.6.2 TFT LCD module 382
16.7 Bibliographic notes 382
16.8 Suggested experiments 382
16.8.1 Inclination sensing 382
16.8.2 “Tapping” detection 382
16.8.3 ADXL362 C++ class 383
16.8.4 Enhanced SPI controller: part I 383
16.8.5 Enhanced SPI controller: part II 383
16.8.6 “Automatic-read” ADXL362 wrapper: part I 383
16.8.7 “Automatic-read” ADXL362 wrapper: part II 384
16.8.8 Flash memory access 384
16.8.9 SPI slave controller: part I 384
16.8.10 SPI slave controller: part II 385
17 I2C Core 387
17.1 Overview 387
17.1.1 Electrical characteristics 388
17.1.2 Basic bus protocol 388
17.1.3 Basic timing 389
17.1.4 Additional features 390
17.2 I2C controller 391
17.2.1 Basic design 391
17.2.2 Conceptual FSMD construction 391
17.2.3 Output control logic 394
17.2.4 I2C bus clock generation 394
17.2.5 HDL implementation 395
17.3 I2C core development 400
17.3.1 Register map 400
17.3.2 Wrapping circuit for the slot interface 400
17.4 I2C driver 401
17.4.1 Class definition 401
17.4.2 Class implementation 402
17.5 Test 405
17.5.1 ADT7420 temperature sensor 405
17.5.2 Test program 406
17.6 Project idea 406
17.7 Bibliographic notes 407
17.8 Suggested experiments 407
17.8.1 Thermometer 407
17.8.2 ADT7420 C++ class 407
17.8.3 Enhanced I2C core 408
17.8.4 “Automatic-read” ADT7420 wrapper 408
17.8.5 I2C slave controller: part I 408
17.8.6 I2C slave controller: part II 408
18 PS2 Core 409
18.1 Introduction 409
18.1.1 PS2-device-to-host communication protocol and timing 410
18.1.2 Host-to-PS2-device communication protocol and timing 410
18.2 PS2 controller 411
18.2.1 Conceptual design 411
18.2.2 PS2 receiving subsystem 411
18.2.3 PS2 transmitting subsystem 415
18.2.4 Complete PS2 system 419
18.3 PS2 core development 420
18.3.1 Register map 420
18.3.2 Wrapping circuit for the slot interface 421
18.4 PS2 driver 422
18.4.1 Class definition 422
18.4.2 Lower layer methods 422
18.4.3 PS2 initialization routine 423
18.4.4 Keyboard routine 425
18.4.5 Mouse routine 428
18.5 Test 430
18.6 Bibliographic notes 431
18.7 Suggested experiments 431
18.7.1 PS2 receiving subsystem with watchdog timer 431
18.7.2 Keyboard-controlled LED flashing circuit 432
18.7.3 Enhanced keyboard driver routine: part I 432
18.7.4 Enhanced keyboard driver routine: part II 432
18.7.5 Remote-mode mouse driver 432
18.7.6 Scroll-wheel mouse driver 432
19 Sound I: DDFS Core 433
19.1 Introduction 433
19.2 Design and implementation 434
19.2.1 Direct synthesis of a digital waveform 434
19.2.2 Direct synthesis of an unmodulated analog waveform 435
19.2.3 Direct synthesis of a modulated analog waveform 436
19.3 Fixed-point arithmetic 437
19.4 DDFS construction 438
19.5 DAC (digital-to-analog converter) 440
19.5.1 Conceptual design 440
19.5.2 HDL implementation 441
19.6 DDFS core development 442
19.6.1 Register map 442
19.6.2 Wrapping circuit for the slot interface 443
19.7 DDFS driver 444
19.7.1 Class definition 444
19.7.2 Class implementation 445
19.8 Test 447
19.9 Bibliographic notes 448
19.10 Suggested experiments 448
19.10.1 Quadrature phase carrier generation 448
19.10.2 Reduced-size phase-to-amplitude lookup table 448
19.10.3 Additive harmonic synthesis 449
19.10.4 Simple function generator 449
19.10.5 Arbitrary waveform generator 449
19.10.6 Sample-based synthesis 449
20 Sound II: ADSR Core 451
20.1 Introduction 451
20.2 ADSR envelope generator 452
20.2.1 Conceptual FSMD design 453
20.2.2 ASMD chart 453
20.2.3 HDL implementation 455
20.3 ADSR core development 457
20.3.1 Register map 457
20.3.2 Wrapped ADSR circuit 458
20.4 ADSR driver 460
20.4.1 Class definition 460
20.4.2 Configuration methods 461
20.4.3 calc note freq() method 463
20.4.4 play note() method 465
20.5 Test 465
20.6 Project idea 466
20.7 Bibliographic notes 467
20.8 Suggested experiments 467
20.8.1 RTTTL music player 467
20.8.2 ADSR envelope testing 467
20.8.3 Pushbutton piano 467
20.8.4 Keyboard piano 468
20.8.5 Keyboard recorder 468
20.8.6 Real-time mode ADSR generator 468
20.8.7 Real-time mode pushbutton piano 468
20.8.8 Merged DDFS and ADSR core 468
20.8.9 ADSR core with an automatic play FIFO buffer 468
20.8.10 ADSR core for frequency modulation 468
PART IV EMBEDDED SOC III: VIDEO CORES
21 Introduction to the Video System 471
21.1 Introduction to a video display 471
21.1.1 Conceptual video display 471
21.1.2 VGA interface 472
21.2 Stream interface 473
21.2.1 Random-access interface versus stream interface 473
21.2.2 Flow control of the stream interface 473
21.3 VGA synchronization 475
21.3.1 Basic operation of a CRT monitor 475
21.3.2 Horizontal synchronization 476
21.3.3 Vertical synchronization 478
21.3.4 Pixel clock rate 479
21.3.5 VGA synchronization circuit 480
21.4 Bar test-pattern generator 483
21.5 Color-to-grayscale conversion circuit 485
21.6 Demo video system 486
21.7 Advanced video standards 488
21.8 Bibliographic notes 489
21.9 Suggested experiments 489
21.9.1 Horizontal bar test-pattern generator 489
21.9.2 Color channel selection circuit 489
21.9.3 Enhanced color-to-grayscale conversion circuit 489
21.9.4 Square test-pattern generator: part I 489
21.9.5 Square test-pattern generator: part II 489
21.9.6 Square test-pattern generator: part III 490
21.9.7 Square test-pattern generator: part IV 490
22 FPro Video Subsystem 491
22.1 Organization of the video subsystem 491
22.1.1 Overview 491
22.1.2 Video controller 493
22.1.3 HDL of the video controller 494
22.2 FPro video IP core 495
22.2.1 Basic functionality 495
22.2.2 Blending operation 496
22.2.3 Core architecture 498
22.2.4 Alternative core partition 500
22.3 Example video cores 500
22.3.1 Bar test-pattern generator core 500
22.3.2 Color-to-grayscale conversion core 503
22.3.3 “Dummy” core 504
22.4 FPro video synchronization core 504
22.4.1 Line buffer 505
22.4.2 Enhanced video synchronization circuit 508
22.4.3 HDL code 511
22.5 Daisy video subsystem 512
22.5.1 Subsystem overview 512
22.5.2 Interface to the video synchronization core 513
22.5.3 HDL code 513
22.5.4 Timing and performance considerations 517
22.6 Vanilla daisy FPro system 517
22.6.1 Clock management core 518
22.6.2 Updated chu_io_map.svh 519
22.6.3 HDL code 519
22.7 Video driver and test program 521
22.7.1 Updated chu_io_map.h and chu_io_rw.h files 521
22.7.2 GPV core driver 522
22.7.3 Test program 523
22.8 Bibliographic notes 524
22.9 Suggested experiments 525
22.9.1 Color channel selection core 525
22.9.2 Enhanced color-to-grayscale conversion core 525
22.9.3 Square test-pattern generator core 525
22.9.4 Alpha blending circuit 525
22.9.5 “Highlight” core 525
22.9.6 SVGA synchronization core 526
22.9.7 Configurable video synchronization core 526
22.9.8 Pipelined video subsystem 526
23 Sprite Core 527
23.1 Introduction 527
23.2 Basic design 528
23.2.1 Sprite RAM 528
23.2.2 In-region comparison circuit 529
23.3 Mouse pointer core 530
23.3.1 Pointer sprite RAM 530
23.3.2 Pixel generation circuit 531
23.3.3 Top-level design 532
23.4 “Ghost” character core 534
23.4.1 Multiple images and animation 534
23.4.2 Overview of the palette scheme 535
23.4.3 Ghost sprite RAM and the palette circuit 535
23.4.4 Animation timing circuit 537
23.4.5 Pixel generation circuit 537
23.4.6 Top-level design 540
23.5 Sprite core driver and test program 541
23.5.1 Sprite core driver 541
23.5.2 Test program 543
23.6 Bibliographic notes 544
23.7 Suggested experiments 544
23.7.1 Mouse pointer control with PS2 core 544
23.7.2 Emulated ghost core 544
23.7.3 Palette circuit for the mouse pointer sprite 544
23.7.4 Sprite scaling circuit 544
23.7.5 Portrait mode display 545
23.7.6 Multiple-object generation 545
23.7.7 Animation speed control 545
23.7.8 Imitated blinking LED: part I 545
23.7.9 Imitated blinking LED: part II 545
23.7.10 Imitated blinking LED: part III 546
24 On-Screen-Display Core 547
24.1 Introduction to tile graphics 547
24.2 Basic OSD design 549
24.2.1 Text-mode display 549
24.2.2 Font ROM 550
24.2.3 Tile RAM 550
24.2.4 Basic organization 551
24.3 OSD core 552
24.3.1 Font ROM 552
24.3.2 Pixel generation circuit 553
24.3.3 Top-level design 555
24.4 OSD core driver and test program 557
24.4.1 OSD core driver 557
24.4.2 Testing program 558
24.5 Bibliographic notes 559
24.6 Suggested experiments 559
24.6.1 Rotating banner 559
24.6.2 Text console 559
24.6.3 Underline for the cursor 559
24.6.4 Portrait-mode display 560
24.6.5 Font scaling circuit: part I 560
24.6.6 Font scaling circuit: part II 560
24.6.7 Extended font 560
24.6.8 Tile-based ghost core 560
25 VGA Frame Buffer Core 561
25.1 Overview 561
25.2 Frame buffer core 562
25.2.1 FPGA memory consideration 562
25.2.2 Video memory module 562
25.2.3 Address translation 563
25.2.4 Pixel generation circuit 564
25.2.5 Register map 566
25.2.6 Top-level HDL code 566
25.3 Driver and test program 567
25.3.1 Frame buffer core driver 567
25.3.2 Geometrical modeling 568
25.3.3 Test program 570
25.4 Project ideas 570
25.5 Bibliographic notes 572
25.6 Suggested experiments 572
25.6.1 Virtual prototyping board panel 572
25.6.2 Virtual analog wall clock 572
25.6.3 Geometrical model functions 572
25.6.4 Simulated “Etch a Sketch” toy 572
25.6.5 Frame buffer core with 3-bit color depth 573
25.6.6 Frame buffer core with 1-bit color depth 573
25.6.7 QVGA frame buffer core 573
25.6.8 Line drawing hardware accelerator 573
25.6.9 Bidirectional frame buffer access: part I 573
25.6.10 Bidirectional frame buffer access: part II 573
PART V EPILOGUE
26 What’s Next 577
References 581
Appendix A: Tutorials 585
A.1 Overview of Xilinx Vivado IDE 585
A.2 Short tutorial on Vivado hardware development 589
A.2.1 Create a design project 590
A.2.2 Add or create Xilinx IP core instances 591
A.2.3 Add or create HDL design files 591
A.2.4 Add a constraint file 592
A.2.5 Perform synthesis, implementation, and bitstream generation 593
A.2.6 Program an FPGA device 593
A.3 Short tutorial on Vivado simulation 594
A.3.1 Add or create HDL testbench 596
A.3.2 Perform initial simulation 596
A.3.3 Customize waveform display 597
A.4 Tutorial on IP instantiation 597
A.4.1 Dual-clock FIFO core via HDL templates 598
A.4.2 IP Catalog utility 599
A.4.3 Generate a MicroBlaze MCS component 600
A.4.4 XADC IP core 601
A.4.5 Clock management IP core 602
A.5 Short tutorial on FPro system development 604
A.5.1 Derive FPro system hardware 605
A.5.2 Export hardware configuration 605
A.5.3 Derive software 605
A.5.4 Embed elf file into FPGA’s memory module and regenerate bitstream 608
A.5.5 Set up the terminal emulator program 610
A.5.6 Program an FPGA device 610
A.6 Bibliographic notes 611
Topic Index 613
