Logic-level mapping of high-level faults

Many high-level fault models have been proposed in the past to perform verification at functional level, however high-level automatic test pattern generators (ATPGs) are still in a prototyping phase, while very efficient logic-level ATPGs are available. On the other side, coverage metrics and functional fault models are used to guide the generation of functional tests achieving high fault coverage in a relatively short time with respect to traditional gate-level ATPGs. However, what is the effectiveness of test sequences generated at functional level with respect to the more traditional gate-level stuck-at fault model? The paper presents an accurate analysis of the correlation between high-level fault models and the gate-level stuck-at fault model and it proposes a strategy to map high-level faults into logic-level faults. Thus, functional verification, based on a high-level fault model, can be performed by exploiting the capability of state of the art logic-level ATPGs. Experimental results highlight the effectiveness of the methodology. (C) 2004 Elsevier B.V. All rights reserved.