SIGMA: A simulator for segment delay faults

We propose an efficient combinational circuit simulation technique for the recently proposed segment delay fault model. After simulation of a vector pair, activated segments are traced using a depth-first search. A segment numbering scheme finds the number of faults to be simulated. A labeling technique generates edge labels to compute a unique label for each segment fault. The use of labels avoids explicit storing of fault lists and allows efficient access to previously detected segment faults. Experimental results demonstrate several advantages of the segment delay fault model. First, the total number of faults remains manageable for small segment lengths. Second, many segments, not included in any robustly testable path fault, may have robust segment delay fault tests. Generating tests for such segments may increase the delay defect coverage.