Simulation-based techniques for dynamic test sequence compaction

Simulation-based techniques for dynamic compaction of test sequences are proposed. The first technique uses a fault simulator to remove test vectors from the partially-specified test sequence generated by a deterministic test generator if the vectors are not needed to detect the target fault, considering that the circuit state may be known. The second technique uses genetic algorithms to fill the unspecified bits in the partially-specified test sequence in order to increase the number of faults detected by the sequence. Significant reductions in test set sizes were observed for all benchmark circuits studied. Fault coverages improved for many of the circuits, and execution times often dropped as well, since fewer faults had to be targeted by the computation-intensive deterministic test generator.