Transcript TOPIC : Fault dominance

TOPIC : FAULT DOMINANCE
Module 2.3
FAULT DOMINANCE

Definition : If all tests of fault F1 detect
another fault F2, then F2 is said to dominate
F1. The two faults are also called
“conditionally” equivalent with respect to
the test set of F1. When two faults F1 and F2
dominate each other, then they are
equivalent.
FAULT DOMINANCE
 Let
T, be the set of all tests that detect a
fault g. We say that a fault f dominates
the fault g iff f and g are functionally
equivalent under T.
 In other words, iff dominates g, then any
test t that detects g.
FAULT DOMINANCE : EXAMPLE
A 3-input AND gate.
 fi -> s-a-1 fault in one input of the gate
 fj -> s-a-1 in the gate output


Tests for fi -> 011
Tests for fj -> 000, 001, 010, 011, 100, 101, 110
 Thus,
fj dominates fi .
FAULT DOMINANCE : CIRCUIT EXAMPLE
Collapsed ratio : 12/30 = 0.40