Impact of test compression on power supply noise control

Compaction and compression are commonly used to minimize test data volume and test application time. Both techniques can greatly affect power supply noise (PSN) during test, as these techniques take advantage of the fact that test patterns have low care-bit density. However, there is little prior work studying how compression affects PSN. In this work, embedded deterministic test (EDT) and Illinois Scan patterns are generated with and without compaction. Our previous PSN control algorithm is extended to incorporate the compression constraints and applied to these patterns. The experimental results show that with the PSN control algorithm, EDT lowers the maximal PSN by 24.15% and Illinois Scan lowers it by 2.77% on un-compacted patterns. The maximal PSN is 22.32% and 6.94% lower on compacted patterns.