Self-checking 1-out-of-n CMOS current-mode checker

In this paper, a 1-out-of-n checker based on current-mode CMOS logic is presented. The proposed design is self-checking for all single faults and for all unidirectional faults. It is applicable to any value of n. The checker consists of two current threshold comparators and n current generators driven by the input code word. Comparison with existing 1-out-of-n checkers shows that the proposed checker is area efficient for large values of n. An application of the checker to the design of a Residue Number System (RNS) processor with fault detection capability is described. This includes a novel high-speed converter for transforming analog signal to 1-out-of-n residue form. A two-stage pipelined converter with fault detection in all digital blocks is presented. Fault detection is incorporated without using redundant moduli whereas conventional RNS scheme assumes redundant moduli for the fault detection.