High Performance Accurate Multiplier using Hybrid Reverse Carry Propagate Adder

A decrease in design complexity via approximate computation will increase performance and power of error-resilient applications. This paper presents a new approximation method for multipliers using the novel hybrid reverse carry propagate adder. In this case, the proposed hybrid Reverse Carry Propagate Adder (RCPA) is utilized to implement approximation method using two variables of a 8-bit multiplier. Reverse carry propagation adders propagate data from MSB to the LSB, which makes the input carrier more relevant than resulting carrier signal. According to probability statistics, the accumulation of altered partial products produces variable likelihood terms. This variation of logic complexity can be explained by altering partial products of the multiplier. Using the proposed Hybrid Reverse Carry Adder in the multiplier leads to an area improvement of 20%, delay and power improvement of 75.7% and 26% respectively. Compared to the ideal approximate reverse carry adder, this structure is more accurate.