A hybrid-type test pattern generating mechanism

We blend the weighted-random-pattern generator and the controllable-linear-feed-back-shift register to develop a hybrid-type test pattern generating mechanism. The whole testing is performed in two phase. The weighted-random-pattern generator drops some of the faults from the fault list during the first phase. Remaining faults will be tested by the controllable-linear-feed-back-shift register to generate the deterministic patterns instead of modifying the configuration of the weighted-random-pattern generator such that a better fault coverage can be achieved with a lower hardware penalty and a shorter test length.