Effectiveness of scan-based delay fault tests in diagnosis of transition faults

The effectiveness of various types of scan-based delay fault tests in diagnosis of transition faults is studied. Enhanced scan tests, skewed-load tests, broadside tests, functional broadside tests and a combination of skewed-load and broadside tests are considered. The results indicate, for example, that even if functional broadside tests are 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.