Selective and Accurate Fail Data Capture in Compression Environment for Volume Diagnostics

This paper describes a novel technique to selectively capture the scan fail data for volume diagnosis in the presence of output compression structures in a design. The proposed technique allows accurate fail data capture, at par with the uncompressed scan architectures, without reconfiguring the scan chains. The proposed technique uses the same test patterns as in the compressed scan test. The fail data collected using this technique can directly be used by any standard uncompressed mode diagnosis tools. This technique is also applicable to fail data collection for BISTed memories