Universal delay test sets for logic networks

Abstract

It has been shown earlier that, if we restrict to unate gate network (UGN) realizations, there exist universal test sets for boolean functions. Such a test set only depends on the function f , and checks any UGN realization of f for all multiple stuck-at faults and all robustly testable stuck-open faults. In this paper we prove that these universal test sets are much more powerful than implied by the above results: They also constitute complete delay fault test sets for arbitrary UGN implementations of a given function. This is even true for UGN networks which are not testable with respect to the gate or path delay fault model. Our ability to prove the temporal correctness of such circuit realizations, comes from the fact that we do not argue the correctness of individual paths, but complete path systems. Keywords| Delay test, unate gate networks, universal test sets, design for testability.

Design for Delay Fault Testability of 2-Rail Logic Circuits

“…It is proved that the two-pattern testing of TRLCs with only all-0 and all-1 initial vectors achieves complete fault coverage [8]. Here, we evaluate the area overhead, the fault coverage, and the test application time.…”

“…Here, delay fault testing with the proposed scan design is † The assumed delay fault model of the proposed method is the same as that of the paper [8]. The test set shown in the paper [8] sensitizes all path system robustly.…”

“…The test set shown in the paper [8] sensitizes all path system robustly. On the circuits which pass the test with the test set, any transitions launched on the inputs can be observed within the determined critical delay, if the transitions can propagate to the outputs.…”

“…Sparmann et al showed the universal delay fault test sets which can achieve complete fault coverage for any unate gate network (UGN) realization [8] † .…”

“…No previous scan design has focused on TRLCs. Sparmann et al researched the testability of unate gate network [7], [8]. Since TRLCs are unate, their results are applicable to TRLCs.…”