Design An High Speed 4 – Bit Carry Ripple Adder Using VHDL Code And Implementation on FPGA

This paper presents 4-Bit RCA that is modeled using VHDL. According Review to past researches, from the performance analysis, it can be concluded that Carry select Adder has better performance in terms of area and delay compared to other adders [9]. The Carry Look Ahead Adder had the least Area-Delay product .But had the larger power consumption. A carry-select adder speeds faster than RCA by performing additions in parallel and reducing the maximum carry path. Because of the simulation technique the required area and power consumption of this adder is particularly doubles with respect to RCA [1]. The carry select adder on the other hand, is at the opposite corner since it has the lowest delay (half that of the ripple carry’s) but with a larger area required to compensate for this time gain. But, in this design, the hardware implementation of 4-Bitripple carry adder has been done to analyze the speed and area. This Adder has been design with For Generate code and it can be concluded this RCA had the best Delay, the least area, slice (lut) and low memory usage.

Keywords:

Ripple Carry Adder , Carry Select Adder , Carry Look Ahead Adder , Carry Save Adder , Delay , Area , FPGA