Papers Published

1. Chakrabarty, K; Murray, BT; Hayes, JP, Optimal space compaction of test responses, Proceedings International Test Conference (December, 1995), pp. 834-843, Int. Test Conference [doi] .
   (last updated on 2022/12/30)

   Abstract:
   Many built-in self-testing (BIST) schemes compress the test responses from a k-output circuit to q signature streams, where q ≪ k, a process termed space compaction. The effectiveness of a compaction method can be measured by its compaction ratio c = k/q. However, a high compaction ratio can introduce aliasing, which occurs when a faulty test response maps to the fault-free signature. We investigate the problem of designing zero-aliasing space compaction circuits with maximum compaction ratio cmax. We introduce a graph representation of test responses to study the space compaction process and relate space compactor design to a graph coloring problem. For a given circuit under test, a given fault model, and a given test set, we determine qmin, which yields cmax = k/qmin. This provides a fundamental bound on the cost of signature-based BIST. We develop a systematic design procedure for the synthesis of space compaction circuits and apply it to a number of ISCAS-85 benchmark circuits.