A Totally Self-checking Checker
Niraj Kumar Jha · 1989
It is well known that a large number of errors in VLSI circuits are unidirectional in nature. It has been shown that the L n/2 J -out-of-!? codes are the optimal codes for detecting all unidi- rectional errors. Recently, attention has been focused on detecting only t, not all, unidirectional errors. Borden has shown that a code consist- ing of all length ti words whose weight (number of bits which are 1) is congruent to Ln/2 J modulo (r + 1) is an optimal r-unidirectional error detecting (r-UED) code. For a code to be employed in a self-checking system, a self-checking checker must exist for it. The totally self-checking (TSC) checker is one such checker. Many designs for TSC checkers exist for m-out-of-ti codes. However, no work has been reported on the design of a TSC checker for Borden's code. In this paper we present such a design. This design should lead to greater applicability of Borden's code to self- checking systems. I. INTRODUCTlON