Diagnose Multiple Stuck-at Scan Chain Faults

Prior effect-cause based chain diagnosis algorithms suffer from accuracy and performance problems when multiple stuck-at faults exist on the same scan chain. In this paper, we propose new chain diagnosis algorithms based on dominant fault pair to enhance diagnosis accuracy and efficiency. Several heuristic techniques are proposed, which include (1) double candidate range calculation, (2) dynamic learning and (3) two- dimensional space linear search. The experimental results illustrate the effectiveness and efficiency of the proposed chain diagnosis algorithms.