Test data manipulation techniques for energy-frugal, rapid scan test

Scan-based testing methodologies remedy the testability problem of sequential circuits; yet they suffer from prolonged test time and excessive test power due to numerous shift operations. The significant correlation among test stimuli along with the high density of unspecified bits in test data enables the utilization of the existing test stimulus in the scan chain as the seed for the generation of the subsequent test stimulus, thus reducing both test time and test data volume. The proposed scan-based test scheme accesses only a subset of scan cells for loading the subsequent test stimulus while freezing the remaining scan cells with the preceding test stimulus, thus decreasing scan chain transitions during shift operations. The proposed scan architecture is coupled with test data manipulation techniques which include test stimuli ordering and partitioning algorithms, boosting test time reductions. The experimental results confirm the significant reductions in test application time, test data volume and test power achieved by the proposed scan-based testing methodology.