Logic Design for Array-Based Circuits
Copyright © 1996, 2001, 2002 Donnamaie E. White
Faults and Fault Detection
Last Edit July 22, 2001
Simple Gates - Sequences
The Existence Functions for the SSI gates NAND and NOR are shown in Figure 9-6. The Existence Functions for the SSI gates AND and OR are shown in Figure 9-7. In both figures, the gate, the logic equation it represents and a Marquand Map of the Existence Function is shown. Marquand maps date from the 1880's.
Figure 9.6 Simple SSI Gates: NAND, NOR
Figure 9.7 Simple SSI Gates: AND, OR
The logical distance 1 edges are also shown. The test sequence can start at any node, and traverses each link in both directions. The sequences for the AND and OR gates are shown in Figure 9-8. An analysis of the fault coverage for the AND gate sequence is shown in Figure 9-9.
Figure 9-8 AND, OR Gate Minimal Sequences
Figure 9.9 Sequence Analysis - AND Gate