Current-mode CMOS-based decoder with redundantly represented 0 addend method for multiple-radix signed-digit number

We discuss a new decoder for the multiple-valued signed-digit number, using a current-mode CMOS transistor-oriented circuit structure. In this paper, a new decoding method with the selective summation of a redundantly represented addend ''0 = [-1 r]'' is proposed, where r is the radix and the addend is applied to each digit with a negative value and any consecutively higher digit takes which has a value of 0. A newly designed literal linear circuit is realized, which has a current-switch function that makes independently the short path when each digit has a value of 0. Through the parallel connections of these current switches, the same addend signal at the lower digit is transmitted in a higher speed. The decoder circuit is tested by using the general circuit simulation software SPICE and the circuit characteristics of the selective summation of a redundantly represented 0 addend and the output results of the SD decoding operation were simulated. We also evaluated the decoder circuit in terms of the processing speed and the circuit size.