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Title: Covering Undetected Transition Fault Sites with Optimistic Unspecified Transition Faults under Multicycle Tests
When a transition fault test set leaves undetected transition faults because of logic redundancies, test constraints, or the existence of hard-to-detect faults, it leaves transition fault sites uncovered. For the case where multicycle tests are used, this paper explores the possibility of covering the sites of undetected transition faults by using tests for what are referred to as optimistic unspecified transition faults. For this discussion, a standard transition fault is associated with an extra delay of a single clock cycle. An unspecified transition fault captures in a single fault the behaviors of transition faults of different durations. Because faults with different durations may be detectable or undetectable independently by a multicycle test, an unspecified transition fault may be detected even if the standard transition fault at the same site is undetectable. This effect is enhanced with optimistic unspecified transition faults. The paper describes an iterative test compaction procedure for multicycle tests that supplements the set of standard transition faults with optimistic unspecified transition faults to cover the sites of undetected standard transition faults.
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European Test Symposium
Sponsoring Org:
National Science Foundation
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