An approach to test compaction for scan circuits that enhances at-speed testing

Abstract

We propose a new approach to the generation of compact test sets for scan circuits. Compaction refers here to a reduction in the test application time. The proposed procedure generates an initial test set that is likely to have a low test application time. It then applies an existing static compaction procedure to this initial test set to further compact it. As a by-product, the proposed procedure also results in long primary input sequences, which are applied at-speed. This contributes to the detection of delay defects. We demonstrate through experimental results the advantages of this approach over earlier ones as a method for generating test sets with minimal test application time and long primary input sequences.