The performance of the concurrent fault simulation algorithms in MOZART

MOZART is a concurrent fault simulator for large circuits described in the RT, functional gate, and switch levels. Performance is gained by means of techniques aimed at the reduction of unnecessary activity. Two such techniques are levelized two-pass simulation, which minimizes the number of events and evaluations, and list event scheduling, which allows optimized processing of simultaneous (fraternal) events for concurrent machines. Moreover, efficient handling of abnormally large or active faulty machines can dramatically improve fault simulator performance. These and related issues are discussed, and analytical and experimental evidence is provided for the effectiveness of the solutions adopted in MOZART. A novel performance metric is introduced for fault simulation that is based on comparison with the serial algorithm and is more accurate than those currently used.<>