Pass/Fail Data for Logic Diagnosis Under Bounded Transparent Scan
Irith Pomeranz · IEEE Transactions on Computer-Aided Design of Integrated Circuits and Systems · 2021
Logic diagnosis to support yield improvement requires the collection of fail data. The full fail data for a faulty unit consist of the tests and observable outputs where the faulty unit produces faulty values. The volume of fail data that needs to be collected can be excessive. A recent solution is to use only pass/fail data for as many tests as possible. With pass/fail data for a test, the full fail data is replaced with a single bit that indicates whether the faulty unit passed or failed the test. However, with conventional scan-based tests, some tests require the full fail data to preserve the diagnostic quality of the test set. This article observes that the use of scan-based tests under bounded transparent-scan increases the diagnostic quality achievable using only pass/fail data. The article describes a test generation procedure for bounded transparent scan that uses only pass/fail data, and targets the same diagnostic quality as a conventional scan-based test set with full fail data. The experimental results demonstrate that, for many of the benchmark circuits considered, a bounded transparent-scan test set with pass/fail data matches the diagnostic quality of a conventional scan-based test set with full fail data.