Unformatted text preview: circuit. In other words, if the off-input b is not late, then it may be possible to relax the steady noncontrolling value somewhat. In this example, if the transition on the target path through a is late, and if the transition on the off-input is on time, then the output c will still have a faulty value. Therefore, it may be sufficient to require the values of X 1 for b instead of a steady 1. This sensitization condition is called the nonrobust sensitization condition. Figure 4.51 illustrates an example of a path, ↑ bcdf , that is robustly untestable but is nonrobustly testable. Note that in a robustly testable path, a transition is present at every gate along the path. On the other hand, in a nonrobustly testable path, some transitions may be lost along the path. In the example shown in Figure 4.51, the transition is lost at f . f a e d c b S 1 ± FIGURE 4.51 A nonrobust path....
View Full Document
- Spring '08
- The Circuit, steady noncontrolling value