QUANTITATIVE-ANALYSIS FOR LINEAR HYBRID CELLULAR-AUTOMATA AND LFSR ASBUILT-IN SELF-TEST GENERATORS FOR SEQUENTIAL FAULTS

This paper presents a combinatorial method of evaluating the effective ness of linear hybrid cellular automata (LHCA) and linear feedback shi ft registers (LFSR) as generators for stimulating faults requiring a p air of vectors. We provide a theoretical analysis and empirical compar isons to see why the LHCA are better than the LFSRs as generators for sequential-type faults in a built-in self-test environment. Based on t he concept of a partner set, the method derives the number of distinct k-cell substate vectors which have 2(2k), 1 less than or equal to k l ess than or equal to [n/2], transition capability for an n-cell LHCA a nd an n-cell LFSR with maximum length cycles. Simulation studies of th e ISCAS85 benchmark circuits provide evidence of the effectiveness of the theoretrical metric.