An Efficient Response Compactor for Extended Compatibilities Scan Tree Construction

Scan tree techniques reduce test application time drastically by shifting the same test data into the compatible scan cells simultaneously．However,both its test pins and test response data volume increase．This paper proposes a test response compactor for extended compatibilities scan tree construction based on an XOR-network to reduce the test pins,test response data volume and to overcome the error bits diffuse problem at the same time．The proposed compactor consists of a diffusion control logic and an XOR-network．The diffusion control logic eliminates the error bits diffusion problem．Experimental results show that the proposed compactor brings 0 aliasing for ISCAS'89benchmark circuits while the compaction ratio is up to 74X．