Volume : II, Issue : VI, June - 2013

Design and Characterization of PPA and Comparing with RCA and CSA in EDA Tool

Nitish Kumar, Alok Ranjan, Dr. Ramesh Kumar

Abstract :

The binary adder is the critical element in most digital circuit designs including digital signal processors (DSP) and microprocessor data path units. As such, extensive research continues to be focused on improving the power, delay performance of the adder. Parallel-prefix adders (also known as carry-tree adders) are known to have the best performance in VLSI designs. This dissertation investigates four types of carry-tree adders (the Kogge-Stone, sparse Kogge-Stone, spanning tree adder and Brunt-Kung adders) and compares them to the simple Ripple Carry Adder (RCA) and Carry Skip Adder (CSA). These designs of varied bit-widths were implemented in a Xilinx and delay measurements were made with a high-performance logic analyzer. In this project for simulation we use Modelsim for logical verification, and further synthesizing it on Xilinx-ISE tool Summary Both measured and simulation results from the study have shown that parallel-prefix adders are not as effective as the simple ripplecarry adder at low to moderate bit widths. This is not unexpected as the Xilinx FPGA has a fast carry chain which optimizes the performance of the ripple carry adder. However, contrary to other studies, we have indications that the carry-tree adders eventually surpass the performance of the linear adder designs at high bit-widths. This is important for large adders used in precision arithmetic and cryptographic applications where the addition of numbers on the order of a thousand bits is not uncommon. Because the adder is often the critical element which determines to a large part the cycle time and power dissipation for many digital signal processing and cryptographical implementations, it would be worthwhile for future FPGA designs to include an optimized carry path to enable tree based adder designs to be optimized for place and routing.

Keywords :

Article: Download PDF   DOI : 10.36106/ijsr  

Cite This Article:

Nitish Kumar, Alok Ranjan, (Dr.) Ramesh Kumar Design and Characterization of PPA and Comparing with RCA and CSA in EDA Tool International Journal of Scientific Research, Vol : 2, Issue : 6 June 2013

Number of Downloads : 951

References :