Timing Analysis and Simulation for Signal Integrity Engineers

Every day, companies call upon their signal integrity engineers to make difficult decisions about design constraints and timing margins.Can I move these wires closer together? How many holes can I drill in this net? How far apart can I place these chips? Each design is unique: theres no single recipe that answers all the questions. Todays designs require ever greater precision, but design guides for specific digital interfaces are by nature conservative. Now, for the first time, theres a complete guide to timing analysis and simulation that will help you manage the tradeoffs between signal integrity, performance, and cost.

Writing from the perspective of a practicing SI engineer and team lead, Greg Edlund of IBM presents deep knowledge and quantitative techniques for making better decisions about digital interface design. Edlund shares his insights into how and why digital interfaces fail, revealing how fundamental sources of pathological effects can combine to create fault conditions. You wont just learn Edlunds expert techniques for avoiding failures: youll learn how to develop the right approach foryour own projects and environment.

Coverage includes
Systematically ensure that interfaces will operate with positive timing margin over the products lifetimewithout incurring excess cost
Understand essential chip-to-chip timing concepts in the context of signal integrity
Collect the right information upfront, so you can analyze new designs more effectively
Review the circuits that store information in CMOS state machinesand how they fail
Learn how to time common-clock, source synchronous, and high-speed serial transfers
Thoroughly understand how interconnect electrical characteristics affect timing: propagation delay, impedance profile, crosstalk, resonances, and frequency-dependent loss
Model 3D discontinuities using electromagnetic field solvers
Walk through four case studies: coupled differential vias, land grid array connector, DDR2 memory data transfer, and PCI Express channel
Appendices present a refresher on SPICE modeling and a high-level conceptual framework for electromagnetic field behavior
Objective, realistic, and practical, this is the signal integrity resource engineers have been searching for.

Preface xiii
Acknowledgments xvi
About the Author xix
About the Cover xx

Chapter 1: Engineering Reliable Digital Interfaces 1
Chapter 2: Chip-to-Chip Timing 13
Chapter 3: Inside IO Circuits 39
Chapter 4: Modeling 3D Discontinuities 73
Chapter 5: Practical 3D Examples 101
Chapter 6: DDR2 Case Study 133
Chapter 7: PCI Express Case Study 175

Appendix A: A Short CMOS and SPICE Primer 209
Appendix B: A Stroll Through 3D Fields 219

Endnotes 233
Index 235