On Reduction of Deterministic Test Pattern Sets

Test compaction and the associated test data compression are two key components of the post-production test as they reduce test pattern counts, the resultant test data volume, test application time, and hence the cost of testing. The paper describes a method that strives to reduce the number of ATPG-produced deterministic test patterns to deliver compact test sets. In principle, it is based on a dimensionality reduction paradigm by working with a meaningful representation of test patterns using external and internal necessary assignments to determine small groups of potentially compatible faults. These faults are subsequently retargeted by the robust SAT-based ATPG and its solvers producing a single test pattern for the entire group, thus making the resultant test set smaller in size. Experimental results obtained for several industrial designs and stuck-at faults confirm superiority of the proposed scheme over state-of-the-art test set compaction techniques and are reported herein.