CiNii Books - CMOS VLSI design : a circuits and systems perspective

The extensively revised 3rd edition of CMOS VLSI Design details modern techniques for the design of complex and high performance CMOS Systems-on-Chip. The authors draw upon extensive industry and classroom experience to explain modern practices of chip design. The introductory chapter covers transistor operation, CMOS gate design, fabrication, and layout at a level accessible to anyone with an elementary knowledge of digital electornics. Later chapters beuild up an in-depth discussion of the design of complex, high performance, low power CMOS Systems-on-Chip.

Table of Contents

Chapter 1 Introduction 1.1 A Brief History. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1 1.2 Preview. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6 1.3 MOS Transistors. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6 1.4 CMOS Logic. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9 1.4.1 The Inverter 9 1.4.2 The NAND Gate 9 1.4.3 CMOS Logic Gates 9 1.4.4The NOR Gate 11 1.4.5 Compound Gates 11 1.4.6 Pass Transistors and Transmission Gates 12 1.4.7 Tristates 14 1.4.8 Multiplexers 15 1.4.9 Sequential Circuits 16 1.5 CMOS Fabrication and Layout. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19 1.5.1 Inverter Cross-Section 19 1.5.2 Fabrication Process 20 1.5.3 Layout Design Rules 24 1.5.4 Gate Layouts 27 1.5.5 Stick Diagrams 28 1.6 Design Partitioning. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 29 1.6.1 Design Abstractions 30 1.6.2 Structured Design 31 1.6.3 Behavioral, Structural, and Physical Domains 31 1.7 Example: A Simple MIPS Microprocessor. . . . . . . . . . . . . . . . . . . . . . . . . . . 33 1.7.1 MIPS Architecture 33 1.7.2 Multicycle MIPS Microarchitectures 34 1.8 Logic Design. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 38 1.8.1 Top-Level Interfaces 38 1.8.2 Block Diagrams 38 1.8.3 Hierarchy 40 1.8.4 Hardware Description Languages 40 1.9 Circuit Design. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 42 1.10 Physical Design. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 45 1.10.1 Floorplanning 45 1.10.2 Standard Cells 48 1.10.3 Pitch Matching 50 1.10.4 Slice Plans 50 1.10.5 Arrays 51 1.10.6 Area Estimation 51 1.11 Design Verification. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 53 1.12 Fabrication, Packaging, and Testing. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 54 Summary and a Look Ahead 55 Exercises 57 Chapter 2 MOS Transistor Theory 2.1 Introduction. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 61 2.2 Long-Channel I-V Characteristics. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 64 2.3 C-V Characteristics. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 68 2.3.1 Simple MOS Capacitance Models 68 2.3.2 Detailed MOS Gate Capacitance Model 70 2.3.3 Detailed MOS Diffusion Capacitance Model 72 2.4 Nonideal I-V Effects. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 74 2.4.1 Mobility Degradation and Velocity Saturation 75 2.4.2 Channel Length Modulation 78 2.4.3 Threshold Voltage Effects 79 2.4.4 Leakage 80 2.4.5 Temperature Dependence 85 2.4.6 Geometry Dependence 86 2.4.7 Summary 86 2.5 DC Transfer Characteristics. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 87 2.5.1 Static CMOS Inverter DC Characteristics 88 2.5.2 Beta Ratio Effects 90 2.5.3 Noise Margin 91 2.5.4 Pass Transistor DC Characteristics 92 2.6 Pitfalls and Fallacies. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 93 Summary 94 Exercises 95 Chapter 3 CMOS Processing Technology 3.1 Introduction. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 99 3.2 CMOS Technologies. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 100 3.2.1 Wafer Formation 100 3.2.2 Photolithography 101 3.2.3 Well and Channel Formation 103 3.2.4 Silicon Dioxide (SiO2) 105 3.2.5 Isolation 106 3.2.6 Gate Oxide 107 3.2.7 Gate and Source/Drain Formations 108 3.2.8 Contacts and Metallization 110 3.2.9 Passivation 112 3.2.10 Metrology 112 3.3 Layout Design Rules . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 113 3.3.1 Design Rule Background 113 3.3.2 Scribe Line and Other Structures 116 3.3.3 MOSIS Scalable CMOS Design Rules 117 3.3.4 Micron Design Rules 118 3.4 CMOS Process Enhancements . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 119 3.4.1 Transistors 119 3.4.2 Interconnect 122 3.4.3 Circuit Elements 124 3.4.4 Beyond Conventional CMOS 129 3.5 Technology-Related CAD Issues . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 130 3.5.1 Design Rule Checking (DRC) 131 3.5.2 Circuit Extraction 132 3.6 Manufacturing Issues . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 133 3.6.1 Antenna Rules 133 3.6.2 Layer Density Rules 134 3.6.3 Resolution Enhancement Rules 134 3.6.4 Metal Slotting Rules 135 3.6.5 Yield Enhancement Guidelines 135 3.7 Pitfalls and Fallacies . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 136 3.8 Historical Perspective . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 137 Summary 139 Exercises 139 Chapter 4 Delay 4.1 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 141 4.1.1 Definitions 141 4.1.2 Timing Optimization 142 4.2 Transient Response . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 143 4.3 RC Delay Model . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 146 4.3.1 Effective Resistance 146 4.3.2 Gate and Diffusion Capacitance 147 4.3.3 Equivalent RC Circuits 147 4.3.4 Transient Response 148 4.3.5 Elmore Delay 150 4.3.6 Layout Dependence of Capacitance 153 4.3.7 Determining Effective Resistance 154 4.4 Linear Delay Model . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 155 4.4.1 Logical Effort 156 4.4.2 Parasitic Delay 156 4.4.3 Delay in a Logic Gate 158 4.4.4 Drive 159 4.4.5 Extracting Logical Effort from Datasheets 159 4.4.6 Limitations to the Linear Delay Model 160 4.5 Logical Effort of Paths . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 163 4.5.1 Delay in Multistage Logic Networks 163 4.5.2 Choosing the Best Number of Stages 166 4.5.3 Example 168 4.5.4 Summary and Observations 169 4.5.5 Limitations of Logical Effort 171 4.5.6 Iterative Solutions for Sizing 171 4.6 Timing Analysis Delay Models . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 173 4.6.1 Slope-Based Linear Model 173 4.6.2 Nonlinear Delay Model 174 4.6.3 Current Source Model 174 4.7 Pitfalls and Fallacies . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 174 4.8 Historical Perspective . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 175 Summary 176 Exercises 176 Chapter 5 Power 5.1 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 181 5.1.1 Definitions 182 5.1.2 Examples 182 5.1.3 Sources of Power Dissipation 184 5.2 Dynamic Power . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 185 5.2.1 Activity Factor 186 5.2.2 Capacitance 188 5.2.3 Voltage 190 5.2.4 Frequency 192 5.2.5 Short-Circuit Current 193 5.2.6 Resonant Circuits 193 5.3 Static Power . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 194 5.3.1 Static Power Sources 194 5.3.2 Power Gating 197 5.3.3 Multiple Threshold Voltages and Oxide Thicknesses 199 5.3.4 Variable Threshold Voltages 199 5.3.5 Input Vector Control 200 5.4 Energy-Delay Optimization . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 200 5.4.1 Minimum Energy 200 5.4.2 Minimum Energy-Delay Product 203 5.4.3 Minimum Energy Under a Delay Constraint 203 5.5 Low Power Architectures . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 204 5.5.1 Microarchitecture 204 5.5.2 Parallelism and Pipelining 204 5.5.3 Power Management Modes 205 5.6 Pitfalls and Fallacies . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 206 5.7 Historical Perspective . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 207 Summary 209 Exercises 209 Chapter 6 Interconnect 6.1 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 211 6.1.1 Wire Geometry 211 6.1.2 Example: Intel Metal Stacks 212 6.2 Interconnect Modeling . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 213 6.2.1 Resistance 214 6.2.2 Capacitance 215 6.2.3 Inductance 218 6.2.4 Skin Effect 219 6.2.5 Temperature Dependence 220 6.3 Interconnect Impact . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 220 6.3.1 Delay 220 6.3.2 Energy 222 6.3.3 Crosstalk 222 6.3.4 Inductive Effects 224 6.3.5 An Aside on Effective Resistance and Elmore Delay 227 6.4 Interconnect Engineering . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 229 6.4.1 Width, Spacing, and Layer 229 6.4.2 Repeaters 230 6.4.3 Crosstalk Control 232 6.4.4 Low-Swing Signaling 234 6.4.5 Regenerators 236 6.5 Logical Effort with Wires . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 236 6.6 Pitfalls and Fallacies . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 237 Summary 238 Exercises 238 Chapter 7 Robustness 7.1 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 241 7.2 Variability . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 241 7.2.1 Supply Voltage 242 7.2.2 Temperature 242 7.2.3 Process Variation 243 7.2.4 Design Corners 244 7.3 Reliability . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 246 7.3.1 Reliability Terminology 246 7.3.2 Oxide Wearout 247 7.3.3 Interconnect Wearout 249 7.3.4 Soft Errors 251 7.3.5 Overvoltage Failure 252 7.3.6 Latchup 253 7.4 Scaling . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 254 7.4.1 Transistor Scaling 255 7.4.2 Interconnect Scaling 257 7.4.3 International Technology Roadmap for Semiconductors 258 7.4.4 Impacts on Design 259 7.5 Statistical Analysis of Variability . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 263 7.5.1 Properties of Random Variables 263 7.5.2 Variation Sources 266 7.5.3 Variation Impacts 269 7.6 Variation-Tolerant Design . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 274 7.6.1 Adaptive Control 275 7.6.2 Fault Tolerance 275 7.7 Pitfalls and Fallacies . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 277 7.8 Historical Perspective . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 278 Summary 284 Exercises 284 Chapter 8 Circuit Simulation 8.1 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 287 8.2 A SPICE Tutorial . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 288 8.2.1 Sources and Passive Components 288 8.2.2 Transistor DC Analysis 292 8.2.3 Inverter Transient Analysis 292 8.2.4 Subcircuits and Measurement 294 8.2.5 Optimization 296 8.2.6 Other HSPICE Commands 298 8.3 Device Models . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 298 8.3.1 Level 1 Models 299 8.3.2 Level 2 and 3 Models 300 8.3.3 BSIM Models 300 8.3.4 Diffusion Capacitance Models 300 8.3.5 Design Corners 302 8.4 Device Characterization . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 303 8.4.1 I-V Characteristics 303 8.4.2 Threshold Voltage 306 8.4.3 Gate Capacitance 308 8.4.4 Parasitic Capacitance 308 8.4.5 Effective Resistance 310 8.4.6 Comparison of Processes 311 8.4.7 Process and Environmental Sensitivity 313 8.5 Circuit Characterization . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 313 8.5.1 Path Simulations 313 8.5.2 DC Transfer Characteristics 315 8.5.3 Logical Effort 315 8.5.4 Power and Energy 318 8.5.5 Simulating Mismatches 319 8.5.6 Monte Carlo Simulation 319 8.6 Interconnect Simulation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 319 8.7 Pitfalls and Fallacies . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 322 Summary 324 Exercises 324 Chapter 9 Combinational Circuit Design 9.1 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 327 9.2 Circuit Families . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 328 9.2.1 Static CMOS 329 9.2.2 Ratioed Circuits 334 9.2.3 Cascode Voltage Switch Logic 339 9.2.4 Dynamic Circuits 339 9.2.5 Pass-Transistor Circuits 349 9.3 Circuit Pitfalls . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 354 9.3.1 Threshold Drops 355 9.3.2 Ratio Failures 355 9.3.3 Leakage 356 9.3.4 Charge Sharing 356 9.3.5 Power Supply Noise 356 9.3.6 Hot Spots 357 9.3.7 Minority Carrier Injection 357 9.3.8 Back-Gate Coupling 358 9.3.9 Diffusion Input Noise Sensitivity 358 9.3.10 Process Sensitivity 358 9.3.11 Example: Domino Noise Budgets 359 9.4 More Circuit Families . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 360 9.5 Silicon-On-Insulator Circuit Design . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 360 9.5.1 Floating Body Voltage 361 9.5.2 SOI Advantages 362 9.5.3 SOI Disadvantages 362 9.5.4 Implications for Circuit Styles 363 9.5.5 Summary 364 9.6 Subthreshold Circuit Design . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 364 9.6.1 Sizing 365 9.6.2 Gate Selection 365 9.7 Pitfalls and Fallacies . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 366 9.8 Historical Perspective . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 367 Summary 369 Exercises 370 Chapter 10 Sequential Circuit Design 10.1 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 375 10.2 Sequencing Static Circuits . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 376 10.2.1 Sequencing Methods 376 10.2.2 Max-Delay Constraints 379 10.2.3 Min-Delay Constraints 383 10.2.4 Time Borrowing 386 10.2.5 Clock Skew 389 10.3 Circuit Design of Latches and Flip-Flops . . . . . . . . . . . . . . . . . . . . . . . . . . . 391 10.3.1 Conventional CMOS Latches 392 10.3.2 Conventional CMOS Flip-Flops 393 10.3.3 Pulsed Latches 395 10.3.4 Resettable Latches and Flip-Flops 396 10.3.5 Enabled Latches and Flip-Flops 397 10.3.6 Incorporating Logic into Latches 398 10.3.7 Klass Semidynamic Flip-Flop (SDFF) 399 10.3.8 Differential Flip-Flops 399 10.3.9 Dual Edge-Triggered Flip-Flops 400 10.3.10 Radiation-Hardened Flip-Flops 401 10.3.11 True Single-Phase-Clock (TSPC) Latches and Flip-Flops 402 10.4 Static Sequencing Element Methodology . . . . . . . . . . . . . . . . . . . . . . . . . . . 402 10.4.1 Choice of Elements 403 10.4.2 Characterizing Sequencing Element Delays 405 10.4.3 State Retention Registers 408 10.4.4 Level-Converter Flip-Flops 408 10.4.5 Design Margin and Adaptive Sequential Elements 409 10.4.6 Two-Phase Timing Types 411 10.5 Sequencing Dynamic Circuits . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 411 10.6 Synchronizers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 411 10.6.1 Metastability 412 10.6.2 A Simple Synchronizer 415 10.6.3 Communicating Between Asynchronous Clock Domains 416 10.6.4 Common Synchronizer Mistakes 417 10.6.5 Arbiters 419 10.6.6 Degrees of Synchrony 419 10.7 Wave Pipelining . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 420 10.8 Pitfalls and Fallacies . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 422 10.9 Case Study: Pentium 4 and Itanium 2 Sequencing Methodologies . . . . . 423 Summary 423 Exercises 425 Chapter 11 Datapath Subsystems 11.1 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 429 11.2 Addition/Subtraction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 429 11.2.1 Single-Bit Addition 430 11.2.2 Carry-Propagate Addition 434 11.2.3 Subtraction 458 11.2.4 Multiple-Input Addition 458 11.2.5 Flagged Prefix Adders 459 11.3 One/Zero Detectors . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 461 11.4 Comparators . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 462 11.4.1 Magnitude Comparator 462 11.4.2 Equality Comparator 462 11.4.3 K = A + B Comparator 463 11.5 Counters . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 463 11.5.1 Binary Counters 464 11.5.2 Fast Binary Counters 465 11.5.3 Ring and Johnson Counters 466 11.5.4 Linear-Feedback Shift Registers 466 11.6 Boolean Logical Operations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 468 11.7 Coding . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 468 11.7.1 Parity 468 11.7.2 Error-Correcting Codes 468 11.7.3 Gray Codes 470 11.7.4 XOR/XNOR Circuit Forms 471 11.8 Shifters . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 472 11.8.1 Funnel Shifter 473 11.8.2 Barrel Shifter 475 11.8.3 Alternative Shift Functions 476 11.9 Multiplication . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 476 11.9.1 Unsigned Array Multiplication 478 11.9.2 Two's Complement Array Multiplication 479 11.9.3 Booth Encoding 480 11.9.4 Column Addition 485 11.9.5 Final Addition 489 11.9.6 Fused Multiply-Add 490 11.9.7 Serial Multiplication 490 11.9.8 Summary 490 11.10 Parallel-Prefix Computations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 491 11.11 Pitfalls and Fallacies . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 493 Summary 494 Exercises 494 Chapter 12 Array Subsystems 12.1 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 497 12.2 SRAM . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 498 12.2.1 SRAM Cells 499 12.2.2 Row Circuitry 506 12.2.3 Column Circuitry 510 12.2.4 Multi-Ported SRAM and Register Files 514 12.2.5 Large SRAMs 515 12.2.6 Low-Power SRAMs 517 12.2.7 Area, Delay, and Power of RAMs and Register Files 520 12.3 DRAM . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 522 12.3.1 Subarray Architectures 523 12.3.2 Column Circuitry 525 12.3.3 Embedded DRAM 526 12.4 Read-Only Memory . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 527 12.4.1 Programmable ROMs 529 12.4.2 NAND ROMs 530 12.4.3 Flash 531 12.5 Serial Access Memories . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 533 12.5.1 Shift Registers 533 12.5.2 Queues (FIFO, LIFO) 533 12.6 Content-Addressable Memory . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 535 12.7 Programmable Logic Arrays . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 537 12.8 Robust Memory Design . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 541 12.8.1 Redundancy 541 12.8.2 Error Correcting Codes (ECC) 543 12.8.3 Radiation Hardening 543 12.9 Historical Perspective . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 544 Summary 545 Exercises 546 Chapter 13 Special-Purpose Subsystems 13.1 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 549 13.2 Packaging and Cooling . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 549 13.2.1 Package Options 549 13.2.2 Chip-to-Package Connections 551 13.2.3 Package Parasitics 552 13.2.4 Heat Dissipation 552 13.2.5 Temperature Sensors 553 13.3 Power Distribution . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 555 13.3.1 On-Chip Power Distribution Network 556 13.3.2 IR Drops 557 13.3.3 L di/dt Noise 558 13.3.4 On-Chip Bypass Capacitance 559 13.3.5 Power Network Modeling 560 13.3.6 Power Supply Filtering 564 13.3.7 Charge Pumps 564 13.3.8 Substrate Noise 565 13.3.9 Energy Scavenging 565 13.4 Clocks . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 566 13.4.1 Definitions 566 13.4.2 Clock System Architecture 568 13.4.3 Global Clock Generation 569 13.4.4 Global Clock Distribution 571 13.4.5 Local Clock Gaters 575 13.4.6 Clock Skew Budgets 577 13.4.7 Adaptive Deskewing 579 13.5 PLLs and DLLs . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 580 13.5.1 PLLs 580 13.5.2 DLLs 587 13.5.3 Pitfalls 589 13.6 I/0 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 590 13.6.1 Basic I/O Pad Circuits 591 13.6.2 Electrostatic Discharge Protection 593 13.6.3 Example: MOSIS I/O Pads 594 13.6.4 Mixed-Voltage I/O 596 13.7 High-Speed Links . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 597 13.7.1 High-Speed I/O Channels 597 13.7.2 Channel Noise and Interference 600 13.7.3 High-Speed Transmitters and Receivers 601 13.7.4 Synchronous Data Transmission 606 13.7.5 Clock Recovery in Source-Synchronous Systems 606 13.7.6 Clock Recovery in Mesochronous Systems 608 13.7.7 Clock Recovery in Pleisochronous Systems 610 13.8 Random Circuits . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 610 13.8.1 True Random Number Generators 610 13.8.2 Chip Identification 611 13.9 Pitfalls and Fallacies . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 612 Summary 613 Exercises 614 Chapter 14 Design Methodology and Tools 14.1 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 615 14.2 Structured Design Strategies . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 617 14.2.1 A Software Radio-A System Example 618 14.2.2 Hierarchy 620 14.2.3 Regularity 623 14.2.4 Modularity 625 14.2.5 Locality 626 14.2.6 Summary 627 14.3 Design Methods . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 627 14.3.1 Microprocessor/DSP 627 14.3.2 Programmable Logic 628 14.3.3 Gate Array and Sea of Gates Design 631 14.3.4 Cell-Based Design 632 14.3.5 Full Custom Design 634 14.3.6 Platform-Based Design-System on a Chip 635 14.3.7 Summary 636 14.4 Design Flows . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 636 14.4.1 Behavioral Synthesis Design Flow (ASIC Design Flow) 637 14.4.2 Automated Layout Generation 641 14.4.3 Mixed-Signal or Custom-Design Flow 645 14.5 Design Economics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 646 14.5.1 Non-Recurring Engineering Costs (NREs) 647 14.5.2 Recurring Costs 649 14.5.3 Fixed Costs 650 14.5.4 Schedule 651 14.5.5 Personpower 653 14.5.6 Project Management 653 14.5.7 Design Reuse 654 14.6 Data Sheets and Documentation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 655 14.6.1 The Summary 655 14.6.2 Pinout 655 14.6.3 Description of Operation 655 14.6.4 DC Specifications 655 14.6.5 AC Specifications 656 14.6.6 Package Diagram 656 14.6.7 Principles of Operation Manual 656 14.6.8 User Manual 656 14.7 CMOS Physical Design Styles . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 656 14.8 Pitfalls and Fallacies . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 657 Exercises 657 Chapter 15 Testing, Debugging, and Verification 15.1 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 659 15.1.1 Logic Verification 660 15.1.2 Debugging 662 15.1.3 Manufacturing Tests 664 15.2 Testers, Test Fixtures, and Test Programs . . . . . . . . . . . . . . . . . . . . . . . . . . 666 15.2.1 Testers and Test Fixtures 666 15.2.2 Test Programs 668 15.2.3 Handlers 669 15.3 Logic Verification Principles . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 670 15.3.1 Test Vectors 670 15.3.2 Testbenches and Harnesses 671 15.3.3 Regression Testing 671 15.3.4 Version Control 672 15.3.5 Bug Tracking 673 15.4 Silicon Debug Principles . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 673 15.5 Manufacturing Test Principles . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 676 15.5.1 Fault Models 677 15.5.2 Observability 679 15.5.3 Controllability 679 15.5.4 Repeatability 679 15.5.5 Survivability 679 15.5.6 Fault Coverage 680 15.5.7 Automatic Test Pattern Generation (ATPG) 680 15.5.8 Delay Fault Testing 680 15.6 Design for Testability . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 681 15.6.1 Ad Hoc Testing 681 15.6.2 Scan Design 682 15.6.3 Built-In Self-Test (BIST) 684 15.6.4 IDDQ Testing 687 15.6.5 Design for Manufacturability 687 15.7 Boundary Scan . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 688 15.8 Testing in a University Environment . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 689 15.9 Pitfalls and Fallacies . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 690 Summary 697 Exercises 697 Appendix A Hardware Description Languages A.1 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 699 A.1.1 Modules 700 A.1.2 Simulation and Synthesis 701 A.2 Combinational Logic . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 702 A.2.1 Bitwise Operators 702 A.2.2 Comments and White Space 703 A.2.3 Reduction Operators 703 A.2.4 Conditional Assignment 704 A.2.5 Internal Variables 706 A.2.6 Precedence and Other Operators 708 A.2.7 Numbers 708 A.2.8 Zs and Xs 709 A.2.9 Bit Swizzling 711 A.2.10 Delays 712 A.3 Structural Modeling . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 713 A.4 Sequential Logic . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 717 A.4.1 Registers 717 A.4.2 Resettable Registers 718 A.4.3 Enabled Registers 719 A.4.4 Multiple Registers 720 A.4.5 Latches 721 A.4.6 Counters 722 A.4.7 Shift Registers 724 A.5 Combinational Logic with Always / Process Statements . . . . . . . . . . . . . . 724 A.5.1 Case Statements 726 A.5.2 If Statements 729 A.5.3 SystemVerilog Casez 731 A.5.4 Blocking and Nonblocking Assignments 731 A.6 Finite State Machines . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 735 A.6.1 FSM Example 735 A.6.2 State Enumeration 736 A.6.3 FSM with Inputs 738 A.7 Type Idiosyncracies . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 740 A.8 Parameterized Modules . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 742 A.9 Memory . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 745 A.9.1 RAM 745 A.9.2 Multiported Register Files 747 A.9.3 ROM 748 A.10 Testbenches . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 749 A.11 SystemVerilog Netlists . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 754 A.12 Example: MIPS Processor . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 755 A.12.1 Testbench 756 A.12.2 SystemVerilog 757 A.12.3 VHDL 766 Exercises 776 References 785 Index 817 Credits 838

by "Nielsen BookData"

CMOS VLSI design : a circuits and systems perspective

Author(s)

Bibliographic Information

Available at 18 libraries

Search this Book/Journal

Note

Description and Table of Contents

Details

Export