SAT-based post-processing for regional capture power reduction in at-speed scan test generation

With more and more sophisticated low-power design techniques being applied to modern LSI chips for aggressive functional power reduction, the risk of fault-free chips falsely failing production test grows due to excessively high test power compared with functional power. Existing low-power ATPG methods, however, suffer from severe test data inflation and often use unfocused global test power reduction. This paper proposes a novel optimization-SAT-based at-speed scan test generation method that is explicitly targeted at eliminating high-capture-power test vectors in a pre-generated compact test set. This method employs layout information in reducing capture switching activity in a focused regional manner. Experiments demonstrate that the proposed method can effectively eliminate a large number of high-capture-power test vectors with neither test data inflation nor fault coverage loss.