Resolution of Diagnosis Based on Transition Faults

The conventional detection conditions for transition faults do not predict fault effects that may be created when transition faults are activated and/or propagated by pulses (or hazards). For this, detection conditions that take hazards into consideration need to be used. However, since the occurrence of pulses cannot be predicted accurately based on a gate-level circuit description, the transition fault model becomes more susceptible to pattern-dependent effects, where errors on observed outputs that are predicted by the fault model may not appear in a circuit-under-diagnosis. This paper considers the implications of these pattern-dependent effects on the resolution of fault diagnosis based on transition faults.