An Alternative Test Generation for Path Delay Faults by Using N_i-Detection Test Sets

摘要

In this paper, we propose an alternative method that does not generate a test for each path delay fault directly to generate tests for path delay faults. The proposed method generates an N-propagation test-pair set by using an N_i-detection test set for single stuck-at faults. The N-propagation test-pair set is a set of vector pairs which contains N distinct vector pairs for every transition faults at a check point. Check points consist of primary inputs and fanout branches in a circuit. We do not target the path delay faults for test generation, instead, the N-propagation test-pair set is generated for the transition (both rising and falling) faults of check points in the circuit. After generating tests, tests are simulated to determine their effectiveness for singly testable path delay faults and robust path delay faults. Results of experiments on the ISCAS'85 benchmark circuits show that the N-propagation test-pair sets obtained by our method are effective in testing path delay faults.