LFSR-Based Deterministic TPG for Two-Pattern Testing

Abstract

This paper proposes an approach to designing a cost-effective deterministic test pattern generator (TPG) for two-pattern testing. Given a set of pre-generated test-pair set (obtained by an ATPG tool) with a pre-determined (path delay) fault coverage, a simple TPG is synthesized to apply the given test-pair set in a minimal test time. To achieve this objective, a configurable linear feedback shift register (CLFSR) structure is used. Techniques are developed to synthesize such a TPG, which is used to generate an unordered deterministic test-pair set. The resulting TPG is efficient in terms of hardware size and speed performance. Experiments on benchmark circuits indicate that TPG designed using the proposed procedure obtain high path delay fault coverage in short test length.