Selective Test Response Collection for Low-Power Scan Testing with Well-Compressed Test Data

A new test application scheme is proposed for low-power scan testing, which is able to compress test data significantly. A combination of a scan architecture and an existent test compression scheme can compress test data even better. Test power can be reduced greatly based on the new test application scheme, according to which only a subset of scan flip-flops shifts a test vector or captures test responses in any clock cycle. Test response data can be another important problem. A new test response compaction scheme called selective test response collection is proposed to reduce test response data. Selective test response collection combines with a structure-based test response compactor, according to which many test response data can be dropped. Experimental results show that the proposed test application scheme can efficiently reduce test power, compress test stimulus data, and compact test response data while test application cost can be well-controlled.