A mathematical model for estimating acceptable ratio of test patterns

Abstract

Sequential circuit testing has been recognized as one of the most difficult problems in the area of fault detection. Controllability and observability of a sequential circuit is low because of their internal states. Therefore finding suitable sequence of test patterns is becoming increasingly complex. We have proposed a method to estimate an expectation graph by utilizing a mathematical model which exploits probabilistic 4-value system. The expectation graph is used to determine the minimum number of faults detected by a suitable sequence of test patterns. Experimental results show our mathematical model has reduced number of test patterns in specified fault coverage.