Field test for reliability is usually performed with small amount of memory resource, and it requires a new technique which might be somewhat different from the conventional manufacturing tests. This paper proposes a novel technique that improves fault coverage or reduces the number of test vectors that is needed for achieving the given fault coverage on scan-based BIST structure. We evaluate a multi-cycle test method that observes the values of partial flip-flops on a chip during capture-mode. The experimental result shows that the partial observation achieves fault coverage improvement with small hardware overhead than the full observation.
This paper proposes a test compaction method for full scan circuits based on multiple capture clock cycles. The multiple cycle test applies more than one capture clock signals for a circuit after scan shift operation, while the capture clock cycle of the conventional scan test is one. Because every captured value at scan flip-flops is used for fault detection, the opportunity of fault detection for each fault increases. As a result, the number of test vectors would be decreased compared with the single cycle mode. Such a test compaction method would be useful in field test that requires less test data so as to store them on-chip. Experimental results show that the proposed method is effective for test compaction.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.