Accurate path delay fault coverage is feasible

We examine the problem of determining the exact number of path delay faults that a given set of p pairs of patterns detects in a combinational circuit consisting of I lines. Several fault coverage pessimistic heuristics and exact algorithms with worst case exponential behavior have been recently presented with trade-offs between the quality of fault coverage and the time performance. None of the existing approaches has provably good performance. This paper presents the first polynomial time algorithms that calculate the path delay fault coverage exactly. Experimental results on the ISCAS´85 benchmarks demonstrate the effectiveness of the presented approaches