METHOD AND APPARATUS FOR IMPROVING STUCK-AT FAULT DETECTION IN LARGE SCALE INTEGRATED CIRCUIT TESTING

摘要

A bus holder for coupling to an integrated circuit bus driven by aplurality of tri-state devices. The bus holder has a bidirectional port andfirst andsecond test ports. Logic circuitry coupled between the respective ports isconfig-ured such that application of a logic 0 to the first test port causes thebidirectionalport to drive whatever logic value is applied to that port; application of alogic 1 tothe first test port and application of a logic 0 to the second test port pullsthebidirectional port down to a logic 0; and, application of a logic 1 to boththe firstand second test ports pulls the bidirectional port up to a logic 1.