mental improvements during the same period. What is clearly needed in verification techniques and technology is the equivalent of a synthesis productivity breakthrough. In the second edition of Writing Testbenches, Bergeron raises the verification level of abstraction by introducing coverage-driven constrained-random transaction-level self-checking testbenches­ all made possible through the introduction of hardware verification languages (HVLs), such as e from Verisity and OpenVera from Synopsys. The state-of-art methodologies described in Writing Test­ benches will contribute greatly to the much-needed equivalent of a synthesis breakthrough in verification productivity. I not only highly recommend this book, but also I think it should be required reading by anyone involved in design and verification of today's ASIC, SoCs and systems. Harry Foster Chief Architect Verplex Systems, Inc. xviii Writing Testbenches: Functional Verification of HDL Models PREFACE If you survey hardware design groups, you will learn that between 60% and 80% of their effort is now dedicated to verification.

Includes supplementary material: sn.pub/extras

1 What is Verification?.- What is a Testbench?.- The Importance of Verification.- Reconvergence Model.- The Human Factor.- What Is Being Verified?.- Functional Verification Approaches.- Testing Versus Verification.- Design and Verification Reuse.- The Cost of Verification.- Summary.- 2 Verification Tools.- Linting Tools.- Simulators.- Verification Intellectual Property.- Waveform Viewers.- Functional Coverage.- Verification Languages.- Assertions.- Revision Control.- Issue Tracking.- Metrics.- Summary.- 3 The Verification Plan.- The Role of the Verification Plan.- Levels of Verification.- Verification Strategies.- From Specification to Features.- Directed Testbenches Approach.- Coverage-Driven Random-Based Approach.- Summary.- 4 High-Level Modeling.- Behavioral versus RTL Thinking.- You Gotta Have Style!.- Structure of Behavioral Code.- Data Abstraction.- Object-Oriented Programming.- Aspect-Oriented Programming.- The Parallel Simulation Engine.- Race Conditions.- Verilog Portability Issues.- Summary.- 5 Stimulus and Response.- Reference Signals.- Simple Stimulus.- Simple Output.- Complex Stimulus.- Bus-Functional Models.- Response Monitors.- Transaction-Level Interface.- Summary.- 6 Architecting Testbenches.- Test Harness.- VHDL Test Harness.- Design Configuration.- Self-Checking Testbenches.- Directed Stimulus.- Random Stimulus.- Summary.- 7 Simulation Management.- Behavioral Models.- Pass or Fail?.- Managing Simulations.- Regression.- Summary.- Appendix A Coding Guidelines.- Directory Structure.- VHDL Specific.- Verilog Specific.- General Coding Guidelines.- Comments.- Layout.- Syntax.- Debugging.- Naming Guidelines.- Capitalization.- Identifiers.- Constants.- HDL & HVL Specific.- Filenames.- HDL Coding Guidelines.- Structure.- Layout.- VHDL Specific.- Verilog Specific.- Appendix B Glossary.- Afterwords.