Structural In-Field Diagnosis for Random Logic Circuits

2011 Asian Test Symposium

Hellebrand

Indlekofer

et al. 2011

Self Cite

Robust circuits are able to tolerate certain faults, but also pose additional challenges for test and diagnosis. To improve yield, the test must distinguish between critical faults and such faults, that could be compensated during system operation; in addition, efficient diagnosis procedures are needed to support yield ramp-up in the case of critical faults. Previous work on circuits with time redundancy has shown that "signature rollback" can distinguish critical permanent faults from uncritical transient faults. The test is partitioned into shorter sessions, and a rollback is triggered immediately after a faulty session. If the repeated session shows the correct result, then a transient fault is assumed. The reference values for the sessions are represented in a very compact format. Storing only a few bits characterizing the MISR state over time can provide the same quality as storing the complete signature. In this work the signature rollback scheme is extended to an integrated test and diagnosis procedure. It is shown that a single test run with highly compacted reference data is sufficient to reach a comparable diagnostic resolution to that of a diagnostic session without any data compaction.

Section: Built-in Diagnosismentioning

confidence: 99%

“…This paper combines the signature rollback scheme developed in [8] and [10] with a procedure for direct diagnosis. This diagnostic technique is not confined to the stuck-at fault model and supports the diagnosis of a large variety of defect mechanisms [11]. In particular, it allows dealing with transient and intermittent faults.…”

Section: Introductionmentioning

confidence: 99%

Diagnostic Test of Robust Circuits

2011 Asian Test Symposium

Hellebrand

Indlekofer

et al. 2011

Self Cite

“…During production test this infrastructure is mandatory for economic reasons, and it is expensive to switch it off for diagnostic purposes. While state-of-the-art diagnostic solutions support the compaction of scan tests [4], [5], other applications like, for example, system test [6], [7] and field return analysis [8], [9] make use of built-in self-test (BIST) infrastructure to gather failure response data. For such applications with higher compaction requirements, the diagnosis of multiple faults is still an open challenge.…”

Section: Introductionmentioning

confidence: 99%

Diagnosis of multiple faults with highly compacted test responses

2014 19th IEEE European Test Symposium (ETS)

Wunderlich

2014

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Defects cluster, and the probability of a multiple fault is significantly higher than just the product of the single fault probabilities. While this observation is beneficial for high yield, it complicates fault diagnosis. Multiple faults will occur especially often during process learning, yield ramp-up and field return analysis.In this paper, a logic diagnosis algorithm is presented which is robust against multiple faults and which is able to diagnose multiple faults with high accuracy even on compressed test responses as they are produced in embedded test and built-in self-test. The developed solution takes advantage of the linear properties of a MISR compactor to identify a set of faults likely to produce the observed faulty signatures. Experimental results show an improvement in accuracy of up to 22 % over traditional logic diagnosis solutions suitable for comparable compaction ratios.

“…In contrast to that in [9][10] a window-based diagnosis is proposed, where signatures are computed and analyzed for contiguous subsequences of several patterns. Both the XP-SISR and the window-based diagnosis scheme work with considerably reduced response data and support a fully autonomous BISD in a single test run.…”

Section: Introductionmentioning

confidence: 99%

“…The new scheme for mixed-mode diagnosis uses the window-based diagnosis proposed in [9][10], which is fully compatible with the STUMPS architecture [4]. The test is partitioned into windows W 1 , ..., W N , and for each window a cumulative signature is computed and compacted as shown in Figure 1.…”

Section: Introductionmentioning

confidence: 99%

Built-in self-diagnosis exploiting strong diagnostic windows in mixed-mode test

2012 17th Ieee European Test Symposium (Ets)

Hellebrand

Wunderlich

2012

Self Cite

Efficient diagnosis procedures are crucial both for volume and for in-field diagnosis. In either case the underlying test strategy should provide a high coverage of realistic fault mechanisms and support a lowcost implementation. Built-in self-diagnosis (BISD) is a promising solution, if the diagnosis procedure is fully in line with the test flow. However, most known BISD schemes require multiple test runs or modifications of the standard scan-based test infrastructure. Some recent schemes circumvent these problems, but they focus on deterministic patterns to limit the storage requirements for diagnostic data. Thus, they cannot exploit the benefits of a mixed-mode test such as high coverage of non-target faults and reduced test data storage. This paper proposes a BISD scheme using mixed-mode patterns and partitioning the test sequence into "weak" and "strong" diagnostic windows, which are treated differently during diagnosis. As the experimental results show, this improves the coverage of non-target faults and enhances the diagnostic resolution compared to state-of-the-art approaches. At the same time the overall storage overhead for input and response data is considerably reduced. Preprint General Copyright NoticeThis article may be used for research, teaching and private study purposes. Any substantial or systematic reproduction, re-distribution, re-selling, loan or sub-licensing, systematic supply or distribution in any form to anyone is expressly forbidden. This is the author's "personal copy" of the final, accepted version of the paper published by IEEE. Abstract-Efficient diagnosis procedures are crucial both for volume and for in-field diagnosis. In either case the underlying test strategy should provide a high coverage of realistic fault mechanisms and support a low-cost implementation. Built-in self-diagnosis (BISD) is a promising solution, if the diagnosis procedure is fully in line with the test flow. However, most known BISD schemes require multiple test runs or modifications of the standard scan-based test infrastructure. Some recent schemes circumvent these problems, but they focus on deterministic patterns to limit the storage requirements for diagnostic data. Thus, they cannot exploit the benefits of a mixed-mode test such as high coverage of non-target faults and reduced test data storage. This paper proposes a BISD scheme using mixed-mode patterns and partitioning the test sequence into "weak" and "strong" diagnostic windows, which are treated differently during diagnosis. As the experimental results show, this improves the coverage of non-target faults and enhances the diagnostic resolution compared to state-of-the-art approaches. At the same time the overall storage overhead for input and response data is considerably reduced.