An approach for improving the levels of compaction achieved by vector omission

Describes a method referred to as sequence counting to improve on the levels of compaction achievable by vector omission-based static compaction procedures. Such procedures are used to reduce the lengths of test sequences for synchronous sequential circuits without reducing the fault coverage. The unique feature of the proposed approach is that test vectors omitted from the test sequence can be reintroduced at a later time. Reintroducing vectors helps to reduce the compacted test sequence length beyond the length that can be achieved if vectors are omitted permanently. Experimental results are presented to demonstrate the levels of compaction achieved by the sequence counting approach.