Generation of high quality tests for functional sensitizable paths

Some previously published results show that in a number of combinational circuits a significant portion of long paths is neither robustly nor non-robustly testable. However, not all of those untestable paths may be ignored in delay testing. Functional sensitizable paths are robust and non-robust untestable but, under some faulty conditions, may degrade the performance of the circuit. Even though the need for testing functional sensitizable paths was recognized in previous research, up till now, there was no strategy for generating tests for them. In this paper we present an algorithm for generating high quality tests for functional sensitizable paths based on including the timing information into the process of test derivation. Our experimental results prove that the quality of delay testing increases if additional test vectors for functional sensitizable path delay faults are included.