Optimal voltage testing for physically-based faults

In this paper we investigate optimal voltage testing approaches for physically-based faults in CMOS circuits. We describe the general nature of the problem and then focus on two fault types: resistive bridges between gate outputs that cause pattern sensitive functional faults and opens in transmission gates that cause delay faults. In both cases, the traditional stuckat model is inadequate. The test vector to sensitize and propagate a resistive bridging fault is not unique. The traditional greedy test vector selection is optimistic, with some choices having poor real coverage. We realistically model the fault and fault coverage, and describe an optimal selection strategy. In a transmission gate with an open NMOS or PMOS device, the output voltage is degraded, increasing delay and reducing noise margin. We model this fault and show how lowvoltage testing can be used to detect it. Our goal in applying these techniques to all important fault types is to maximize the real coverage of volt...

• Type: Conference
• Year: 1996
• Where: VTS
• Authors: Yuyun Liao, D. M. H. Walker
• Keywords: Fault Types, Hardware, Optimal Voltage Testing, Resistive Bridging Fault, VTS 1996