Multi-valued logic mapping of resistive short and open delay-fault testing in deep sub-micron technologies

In advanced technologies an increasing proportion of defects manifest themselves as small delay faults. Most of today’s advanced delay-fault algorithms are able to propagate those delay faults which create logic or glitch faults. An algorithm is proposed for circuit fault diagnosis in deep sub-micron technology to propagate the actual timing faults as well as those delay faults that eventually create logic faults to the primary outputs. Unlike the backtrack algorithm that predicts the fault site by tracing the syndrome at a faulty output back into the circuit, this approach propagates the fault from the fault site by mapping a nine-valued voltage model on top of a five-valued voltage model. In such a forward approach, accuracy is greatly increased since all composite syndromes at all faulty outputs are considered simultaneously. As a result, the proposed approach is applicable even when the delay size is relatively small. Experimental results show that the number of fault candidates produced by this approach is considerable.