Generating diverse test sets for multiple fault detections based on fault cone partitioning

Testing modeled faults multiple times has been shown to increase the likelihood of a test set to detect non-modeled faults, either static or dynamic, when compared to a single detect test set. Test sets that guarantee detecting every modeled fault with at least n different tests are known as n-detect test sets. Moreover, recent investigations examine how different the various tests for a fault should be, in order to further increase their ability in detecting defects. This work proposes a new test generation methodology for multiple-detect (including n-detect) test sets that increases their diversity in terms of the various fault propagation paths excited by the different tests. Specifically, the various tests per modeled fault are guaranteed to propagate the fault effect via different propagation paths. The proposed method can be applied to any linear, to the circuit size, static or dynamic fault model for multiple fault detections, such as the stuck-at or transition delay fault models, and avoids any path or path segment enumeration. Experimental results show increased numbers of propagation paths and non-modeled fault coverages when compared to traditional n-detect test sets.