On identifying undetectable and redundant faults in synchronous sequential circuits

Considers undetectable and redundant faults in synchronous sequential circuits. The authors state and formally prove results regarding the types of faults identified as undetectable and/or redundant by existing test generation procedures and by procedures proposed specifically for this purpose. They distinguish between procedures that identify undetectable faults and procedures that identify redundant faults. They also give a detailed characterization of the types of faults that can be classified by each procedure considered and the types of faults that cannot be classified. The authors present examples and experimental evidence of these limitations