Scan-Based Delay Fault Tests for Diagnosis of Transition Faults

Abstract

This paper studies the effect of the type of scan-based delay fault tests used for a circuit on the ability to diagnose delay defects by studying its effect on diagnosis of transition faults. The authors consider enhanced scan tests, skewed-load tests, broadside tests, functional broadside tests, and a combination of skewed-load and broadside tests. The results indicate that while functional broadside tests should be used for fault detection to avoid overtesting, the test set should be extended for fault diagnosis by adding other types of tests. Adding a small number of skewed-load tests is especially useful for diagnosis if enhanced scan is not available