Race detection for two-phase systems

Abstract

The authors present RACE2, a tool to find latch race-through in two-phase, non-underlapped-clock systems. Though these systems can run at very high clock speeds, susceptibility to race-through has made them difficult to design. RACE2, by detecting all race-through violations, greatly reduces the design risk on these very fast systems. It combines the exhaustive search of a pattern-independent tool with a knowledge base of fundamental principles about when races are-and are not-important. Planned enhancements include detection of saved-state races, detection of charge-share races, improved robustness, and better pruning methods for faster worst-case runtimes. For pieces of a large two-phase full-custom chip, CPU execution times are in minutes, seconds on a VAX-8800. To date, RACE2 has found five races in the chip, all of which were undetected by design reviews and logic simulation.<>