Efficient new approach for modulo 2n−1 addition in RNS

Abstract

A new modulo 2n−1 addition algorithm is presented, which is applicable in the residue number system. In contrast to previous work, the input carry in the first stage of the addition is set to one. The associated output carry is then used to conditionally modify the sum to produce the correct modulo 2n−1 result. Moreover, unlike recent adders in the literature, the result never exceeds the dynamic range of the modulus. Actual VLSI implementations using 130 nm standard-cell technology show that the corresponding architectures provide improved trade-offs in the power–delay–area space when compared against existing designs.