A self-test approach using accumulators as test pattern generators

Configurations of adders and registers, which are available in many datapaths, can be utilized to generate patterns and to compact test responses. This paper analyzes the pattern sequences produced by different types of accumulators and shows that they can achieve similar fault coverage as pseudo-random patterns. Compared to the well-known self-test methods that insert test registers, the approach using accumulators saves the additional gates that are needed to implement test registers, and it avoids performance degradation due to additional delays.