On Complete Functional Broadside Tests for Transition Faults

Abstract

It was shown before that tests applied under nonfunctional operation conditions, which are made possible by scanning in an unreachable state, may lead to unnecessary yield loss. To address this issue, functional broadside tests were defined as broadside tests that use only reachable states of the circuit as scan-in states. Earlier procedures for generating functional broadside tests were not complete, i.e., they did not always detect all the detectable faults or prove that all the undetectable faults are undetectable. In this paper, we address the completeness of the functional broadside tests for transition faults. We describe the implementation of a test-generation procedure that can, for every transition fault, either find a functional broadside test or prove that the fault is undetectable under the functional broadside tests. We present experimental results where complete results are achieved for almost all the benchmark circuits considered.