Don't Cares based Dynamic Test Vector Compaction in SAT-ATPG

SAT solvers have been used as ATPG solution due to the advantage of transforming the circuit to a mathematical problem that can quickly be solved rather than using traditional circuit based approach. In this paper, we present a novel technique for dynamically compacting the test vector set in SAT-based ATPG as it searches for individual vectors, hence giving out fewer patterns that cover more faults. Three-valued encoding was used to allow the use of don't cares, a value that is not part of the traditional SAT solver approach. Experimental results compare the traditional approach with the one proposed.