Quick scan chain diagnosis using signal profiling

Abstract

In this paper we address the scan chain diagnosis problem. We propose a new diagnosis flow based on the concept of signal profiling to accurately pinpoint the location of a faulty flip-flop in a scan chain. As compared to the conventional cause-effect or effect-cause analysis, this approach is much more computationally efficient because it does not have to simulate the behaviors of a large number of fault candidates. Also, it is general and applicable to all kinds of faults because it does not assume any specific fault model. Experimental results indicate that this approach can instantly catch a fault within a scan chain quite accurately in most cases. © 2005 IEEE.