The Weighted Random Test-Pattern Generator

A heuristic method for generating large-scale integration (LSI) test patterns is described. In particular, this paper presents a technique for generating statistically random sequences to test complex logic circuits. The algorithms used to obtain a set of tests by means of weighted logic signal variations are included. Several techniques for assigning these weights and for varying them are discussed on the basis of the primary algorithm. Also described is a means of obtaining a minimal number of test patterns. This approach has proved successful in obtaining fault-detecting patterns.