Transition-Time-Relation based capture-safety checking for at-speed scan test generation

Excessive capture power in at-speed scan testing may cause timing failures, resulting in test-induced yield loss. This has made capture-safety checking mandatory for test vectors. This paper presents a novel metric, called the TTR (Transition-Time-Relation-based) metric, which takes transition time relations into consideration in capture-safety checking. Capture-safety checking with the TTR metric greatly improves the accuracy of test vector sign-off and low-capture-power test generation.