Hazard-Based Detection Conditions for Improved Transition Path Delay Fault Coverage

Transition path delay faults were defined to capture the behavior of both small and large delay defects in a single fault model. The number of detectable transition path delay faults as defined earlier is the same or close to the number of conventional path delay faults that are detectable under the strong non-robust propagation conditions. When the weak non-robust propagation conditions are used, the number of detectable conventional path delay faults is significantly higher. Using what are called the hazard-based detection conditions for transition faults, we define detection conditions for transition path delay faults, under which the number of detectable faults is the same or close to the number of conventional path delay faults that are detectable under the weak non-robust propagation conditions. The fault model still captures the behavior of both small and large delay defects, but the number of detectable faults is significantly higher.