Professional Verification is a guide to advanced functional verification in the nanometer era. It presents the best practices in functional verification used today and provides insights on how to solve the problems that verification teams face. Professional Verification is based on the experiences of advanced verification teams throughout the industry, along with work done at Cadence Design Systems. Professional Verification presents a complete and detailed Unified Verification Methodology based on the best practices in use today. It also addresses topics important to those doing advanced functional verification, such as assertions, functional coverage, formal verification, and reactive testbenches.