Reduction of Test Power and Test Data Volume by Power Aware Compression Scheme

This paper presents a new approach to reduce both test power and test data volume without compromising the target fault coverage. To reduce the shift power during testing we are filling the unspecified bits (X-bits) in the test pattern with 0´s or 1´s by observing the effect of each X bit on the shift transition. The shift power and compression rate depends on the percentage of X bits present in the pattern. After filling the X-bits for shift power reduction, the patterns are compressed based on shifted alternating frequency directed run-length coding, which is suitable for encoding pre-computed test set of embedded cores in System-on-Chip(SoC). The experimental results on ISCAS´89 benchmark circuits show that our scheme provides better compression efficiency as well as significant reduction in test power.