A Comparative Study of Radix-4 Adder and Accuracy-Configurable Radix-4 Adder

In this paper a comparative study of normal Radix-4 Adder (RD4A) and Accuracy-Configurable Radix-4 Adder (ACRA) is presented. The RD4A decreases the propagation delay and power consumption of traditional adders such as ripple carry adder (RCA) and carry-lookahead adder (CLA) by operating two bits simultaneously. To reduce the power consumption further and reconfiguring the computational accuracy an ACRA could be used. This accuracy-adjustable adder could be used for various error-tolerant applications. The simulation results obtained from Xilinx ISE 14.7 and comparison between the RD4A and ACRA is presented in this paper. In order to construct a multi-bit adder an RD4A and numerous ACRAs could be added to an ACRA based fully-configurable adder. To further improve the performance of above-mentioned adder an ACRA and PPA (parallel prefix adder) based hybrid adder could be used.