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Unformatted text preview: pseudoexhaustive vectors is simply at most 2 n 1 + 2 n 2 + 2 n 3 . 4.3 THEORETICAL BACKGROUND: BOOLEAN DIFFERENCE Consider the circuit shown in Figure 4.5. Let the target fault be the stuckat0 fault on primary input y . Recall the highlevel concept of test generation illustrated in Figure 4.1, where the objective is to distinguish the faultfree circuit from the faulty circuit. In the example circuit shown in Figure 4.5, the faulty circuit is the circuit with y stuck at 0. Note that the circuit output can be expressed as a Boolean formula: f = xy + yz Let f ± be the faulty circuit with the fault y/ 0 present. In other words, f ± = f²y = ³´ In order to distinguish the faulty circuit f ± from the faultfree counterpart f , any input vector that can make f ⊕ f ± = 1 would suffice. Furthermore, as the aim is test y f w x z ± FIGURE 4.5 Example circuit to illustrate the concept of Boolean difference....
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 Spring '08
 elbarki

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