Method and apparatus for improving stuck-at fault detection in large scale integrated circuit testing

Abstract From the Canadian patent

A bus holder for coupling to an integrated circuit bus driven by a plurality of tri-state devices. The bus holder has a bidirectional port and first and second test ports. Logic circuitry coupled between the respective ports is config- ured such that application of a logic 0 to the first test port causes the bidirectional port to drive whatever logic value is applied to that port; application of a logic 1 to the first test port and application of a logic 0 to the second test port pulls the bidirectional port down to a logic 0; and application of a logic 1 to both the first and second test ports pulls the bidirectional port up to a logic 1.