Low Power Parallel Prefix Adder

Addition is a fundamental operation of all Arithmetic and Logic Units (ALU).The speed of addition operation decides the computational frequency of ALU. In order to improve the performance of the binary adder, the parallel prefix adder are preferred. There are various parallel prefix adders available. This work focuses on designing 8-bit prefix adders such as Brent Kung ,Kogge Stone and Sklansky adders using GDI technique. The performance of these GDI based prefix adders are compared with that of CMOS based prefix adder. GDI based prefix adders out performs CMOS based prefix adders in terms of power delay product (PDP). The design is implemented and simulated by DSCH2 and MICROWIND tool .The simulation result reveal about 31%,40% and 50 % of power saving is attained and the number of transistors also reduced.