Incorporation of Reduced Full Adder and Half Adder into Wallace Multiplier and Improved Carry-Save Adder for Digital FIR Filter

Abstract

Improvement of digital FIR filter is vital in the field of Digital Signal Processing in order to reduce the area, delay and power. Multiplication and Accumulation (MAC) unit of Finite Impulse Response (FIR) filter has been designed using efficient multiplier and adder circuits for optimized APT (Area, Power and Timing) product. In this paper, the design of direct form FIR filter with efficient MAC unit has been presented. Initially, full adder and half adder structures are shrunk down by reducing number of gates. These compact full adder and half adder structures are incorporated into Wallace Multiplier and Improved Carry-Save Adder. The proposed 16-bit Carry-Save Adder has been improved by splitting into four parallel phases. Consequently the delay of enhanced CarrySave Adder is reduced. Generation of carry output is performed using number of OR gates in a sequential manner. All these enhanced architectures are incorporated into the Digital FIR Filter to reduce the area, delay and power utilization.