On Minimization of Test Application Time for RAS

Conventional random access scan (RAS) for testing has lower test application time, low power dissipation, and low test data volume compared to standard serial scan chain based design. In this paper, we present two cluster based techniques, namely, serial input random access scan and variable word length random access scan to reduce test application time even further by exploiting the parallelism among the clusters and performing write operations on multiple bits. Experimental results on benchmarks circuits show on an average 2-3 times speed up in test write time and average 60% reduction in write test data volume.