Automated Observability Analysis for Mixed-Signal Circuits
Stephen Sunter, Krzysztof Jurga · 2021
Recent papers have proposed methods for more efficient mixed-signal test generation, measuring test stimulus quality, and defect simulation. This paper addresses the most time-consuming remaining step to achieving higher quality mixed-signal ICs: diagnosing defects reported as undetected by an analog fault simulator. A unique method for automatically reporting the observability of each undetected defect is described that works for analog, mixed-signal, and even digital circuits (that don't have scan path access). Results are reported for an 8-bit SAR ADC from the ITC'17 A/MS benchmark circuits, and they reveal that most of the undetected defects can be quickly categorized into those that need a better test stimulus, those that need better output analysis, and those that might need better DFT.