Hazard-Based Detection Conditions for Improved Transition Fault Coverage of Functional Test Sequences

It was shown earlier that simulation of a transition fault under a test may indicate that the fault is detected by the test only if detection conditions referred to as hazard-based detection conditions are considered. The hazard-based detection conditions were applied to fault simulation and test generation for transition faults under scan-based tests. In this case, the increase in fault coverage due to the use of the hazard-based detection conditions for test generation may imply that redundant transition faults are detected. Functional test sequences are applied to the primary inputs of the circuit in functional mode. In this case, if a fault is detected due to the use of the hazard-based detection conditions, the fault is guaranteed to be irredundant. Motivated by this observation we study the use of the hazard-based detection conditions for the simulation and generation of functional test sequences.