An Approach for Improving the Levels of Compaction Achieved by Vector Omission

We describe a method referred to as sequence counting to improve on the levels of compaction achievable by vector omis-sion 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 omit-ted from the test sequence can be reintroduced at a later time. Reintroducing of vectors helps reduce the compacted test sequence length beyond the length that can be achieved if vec-tors are omitted permanently. Experimental results are presented to demonstrate the levels of compaction achieved by the sequence counting approach. 1