TESTING OF K-FR CIRCUITS UNDER HIGHLY OBSERVABLE CONDITION

This paper presents the concept of k-FR circuits. The controllability of such a circuit is high due to its special structure. It is shown th at all stuck-at faults and stuck-open faults in a k-FR circuit can be detected and located by k(k+1)+1 test vectors under the highly observa ble condition which assumes the output of every gate to be observable. k is usually two or three. This paper also presents an algorithm for converting an arbitrary combinational circuit into a k-FR circuit. A k -FR circuit is easy to test when using technologies such as the electr on-beam probing, the current measurement, or the CrossCheck testabilit y solution.