Engineering Science and Technology: International Journal (ESTIJ)
Pseudo-random Built-In Self-Test (BIST) generators have been widely utilized to test integrated circuits and systems. For circuits with hard-to-detect faults, a large number of random patterns have to be generated before high fault coverage is achieved. Therefore, weighted pseudorandom techniques have been proposed where inputs are biased by changing the probability of a "0" or a "1" on a given input from 0.5 (for pure pseudorandom tests) to some other value. Weighted pattern generation of an accumulator is achieved by using weights 1, 0, and 0.5 (for pure pseudorandom tests).