Multiplets, Models, and the Search for Meaning: Improving Per-Test Fault Diagnosis

The advantage to "one test at a time" fault diagnosis is its ability to implicate the components of complicated defect behaviors. The disadvantage is the large size and opacity of the diagnostic answer. In this paper, we address the problems of per-test fault diagnosis by improving the candidate matching, introducing scoring and ranking techniques, and by developing a method to translate the results into common defect scenarios. Our experimental results on simulated and introduced defects indicate that not only are the results improved on complex behaviors, but by considering passing test results we improve a common case where per-test algorithms can perform significantly worse than traditional diagnosis algorithms. Finally, our method of candidate analysis provides a way to bridge the per-test approach with traditional model-based fault diagnosis

Beyond the Byzantine Generals: Unexpected Behavior and Bridging Fault Diagnosis

Physical defects cause behaviors unmodeled byeven the best fault simulators, which complicates predictive diagnosis. This paper reports on a diagnosis procedure that uses modi#ed composite signatures constructed from single stuck-at information combined with a lexicographic matching and ranking algorithm. The diagnosis procedure is used to perform highquality bridging fault diagnosis for more than 400,000 diagnostic experiments involving dropping or adding behaviors from the simulations of faulty circuits. 1 Introduction Accurate fault diagnosis is an integral part of failure analysis. The purpose of fault diagnosis is to specify a part of the chip to examine in order to determine the cause of failure. Traditional fault diagnosis compares the observed faulty behavior to behaviors predicted byachosen fault model and fault simulator. As identi#ed by Aitken and Maxwell #4#, the problem has been approached in twoways: via a simple fault model #almost always the single stuck-at model# and..

Diagnosing Realistic Bridging Faults with Single Stuck-at Information

Successful failure analysis requires accurate fault diagnosis. This paper presents a method for diagnosing bridging faults that improves on previous methods. The new method uses single stuck-at fault signatures, produces accurate and precise diagnoses, and takes into account imperfect fault modeling; it accomplishes this byintroducing the concepts of match restriction, match requirement, and match ranking

Diagnosis of Realistic Bridging Faults with Single Stuck-at Information

Precise failure analysis requires accurate fault diagnosis. A previously proposed method for diagnosing bridging faults using single stuck-at dictionaries was applied only to small circuits, produced large and imprecise diagnoses, and did not takeinto account the Byzantine Generals Problem for bridging faults. We analyze the original technique and improveitby introducing the concepts of match restriction, match requirement, and failurerecovery. Our new technique, which requires no information other than that used by standard stuck-at methods, produces diagnoses that are an order of magnitude smaller than those produced by the original technique and produces many fewer misleading diagnoses than that of traditional stuck-at diagnosis. 1 Introduction Accurate fault diagnosis of realistic defects is an integral part of failure analysis. The majorityofspot defects in modern CMOS technologies cause changes in the circuit description that result in electrical shorts #9#, which implies that..

The Case For Reliable Concurrent Multicasting Using Shared Ack Trees

Such interactive, distributed multimedia applications as shared whiteboards, group editors, and simulations require reliable concurrent multicast services, i.e., the reliable dissemination of information from multiple sources to all the members of a group. Furthermore, it makes sense to offer that service on top of the increasingly available IP multicast service, which offers unreliable multicasting. This paper establishes that concurrent reliable multicasting over the Internet should be based on reliable multicast protocols based on a shared acknowledgment tree. First, we show that organizing the receivers of a reliable multicast group into an acknowledgment tree and using NAK-avoidance with periodic polling in local groups inside such a tree provides the highest maximum throughput among all classes of reliable multicast protocols proposed to date. Second, we introduce Lorax, which demonstrates the viability of implementing a reliable multicasting approach in the Internet based on ack..