Compact Test Generation for Small-Delay Defects Using Testable-Path Information

Testing for small-delay defects requires fault-effect propagation along the longest testable paths. However, the selection of the longest testable paths requires high CPU time and leads to large pattern counts. Dynamic test compaction for small-delay defects has remained largely unexplored thus far. We propose a path-selection scheme to accelerate ATPG based on stored testable critical-path information. A new dynamic test-compaction technique based on structural analysis is also introduced. Simulation results are presented for a set of ISCAS´89 benchmark circuits.