Constant multiplier design using specialized bit pattern adders

The problem of efficient hardware implementation of multiple constant multiplication (MCM) is encountered in many digital signal processing applications such as FIR filter and linear transform (e.g., DCT and FFT). It is known that efficient solutions based on common subexpression elimination (CSE) algorithm can yield significant improvements in area and power consumption. In this paper, we present efficient implementation method of two common subexpressions (101, 101) in canonic signed digit (CSD) representation. By Synopsys simulations of a radix-24 FFT example, it is shown that the area, speed and power consumption can be reduced up to 21%, 11% and 12%, respectively, by the proposed algorithm.