scholarly journals Design of high speed Wallace tree multiplier using 8-2 and 4-2 adder compressors

2018 ◽  
Vol 7 (4) ◽  
pp. 2386
Author(s):  
E Jagadeeswara Rao ◽  
K Jayaram Kumar ◽  
Dr. T. V. Prasad

Multiplication is one of the most common arithmetic operations employed in digital systems such as FIR filters and DSP processors but multipliers are the most time, area, and power consuming circuits. Improvement in any of these parameters can be advantageous for improv-ing the efficiency of the circuit. High-speed multiplier which uses the high-speed adder is designed based on the Wallace tree concept in this paper. In this paper first we present an approach towards the reduction of delay in Wallace tree multipliers by using 8:2 and 4:2 adder com-pressors, in the partial product reduction stage. The proposed design is also compared to the Wallace Tree multiplier which uses 4:2 and 8:2 adder compressors in terms of propagation delay. The proposed design enhances speed of the system by 74.1% compared to the conven-tional Wallace Tree multiplier, while 24.1 % reduction was achieved in the delay of the system relative to Wallace tree multiplier with 16-bit adder with one of the 8-2 adder compressors.  

Author(s):  
Sai Venkatramana Prasada G.S ◽  
G. Seshikala ◽  
S. Niranjana

Background: This paper presents the comparative study of power dissipation, delay and power delay product (PDP) of different full adders and multiplier designs. Methods: Full adder is the fundamental operation for any processors, DSP architectures and VLSI systems. Here ten different full adder structures were analyzed for their best performance using a Mentor Graphics tool with 180nm technology. Results: From the analysis result high performance full adder is extracted for further higher level designs. 8T full adder exhibits high speed, low power delay and low power delay product and hence it is considered to construct four different multiplier designs, such as Array multiplier, Baugh Wooley multiplier, Braun multiplier and Wallace Tree multiplier. These different structures of multipliers were designed using 8T full adder and simulated using Mentor Graphics tool in a constant W/L aspect ratio. Conclusion: From the analysis, it is concluded that Wallace Tree multiplier is the high speed multiplier but dissipates comparatively high power. Baugh Wooley multiplier dissipates less power but exhibits more time delay and low PDP.


Author(s):  
A. Arunkumar Gudivada ◽  
K. Jayaram Kumar ◽  
Srinivasa Rao Jajula ◽  
Durga Prasad Siddani ◽  
Praveen Kumar Poola ◽  
...  

2018 ◽  
Vol 7 (2.7) ◽  
pp. 409 ◽  
Author(s):  
R Nikhil ◽  
G V. S. Veerendra ◽  
J Rahul M. S. Sri Harsha ◽  
Dr V. S. V. Prabhakar

Now a days in designing a VLSI circuits we are coming across many problems such as high power intake, delay and large utilization of chip area in order to overcome these problems a new architectures are developed. In our project we deals with FFT computation which internally involves series of multiplication and addition therefore requirement of efficient multipliers is needed and therefore we come across two high speed improved multipliers Booth multiplier and Wallace tree multiplier which are good in terms of power efficiency and low output delay. The main aim of our project involves hybridizing the both Wallace multiplier and Booth multiplier which yields low delay and low power consumption than compared to individual multipliers. The Booth multiplier is used for reduction of partial products and for addition operations carry save adders is used in Wallace tree multipliers and thus hybrid is designed by combining both the algorithms which in turn produces better results and they can be observed in comparisons tabular column in our documentation. These multipliers can be designed in many ways such using cmos layout techniques and also using Verilog programming and we have chosen Verilog programming which requires Xilinx software and codes are developed in gate level design model for the respective multiplier models and the results will be tabulated.  


2016 ◽  
Vol 25 (04) ◽  
pp. 1650027 ◽  
Author(s):  
Kore Sagar Dattatraya ◽  
Belgudri Ritesh Appasaheb ◽  
Ramdas Bhanudas Khaladkar ◽  
V. S. Kanchana Bhaaskaran

Multiplier forms the core building block of any processor, such as the digital signal processor (DSP) and a general purpose microprocessor. As the word length increases, the number of adders or compressors required for the partial product addition also increases. The addition operation of the derived partial products determines the circuit latency, area and speed performance of wider word-length multipliers. Binary count multiplier (BCM) aims to reduce the number of adders and compressors through the use of a uniquely structured binary counter and by suitably altering the logical flow of partial product addition by using binary adders is proposed in this paper. The binary counters for varying bit count values are derived by modifying the basic 4:2 compressor circuit. A [Formula: see text] bit multiplier has been developed to validate the proposed computation method. This logic structure demonstrates lower power operation, reduced device count and lesser delay in comparison against the conventional Wallace tree multiplier structure found in the literature. The BCM implementation realizes 29.17% reduction in the device count, 66% reduction in the delay and 70% reduction in the power dissipation. Furthermore, it realizes 90% reduction in the power delay product (PDP) in comparison against the Wallace tree structure. The multiplier circuits have been implemented and the validation of results has been carried out using Cadence[Formula: see text] EDA tool. Forty five nanometer technology files have been employed for the designs and exhaustive SPICE simulations.


Author(s):  
M. Anitha ◽  
J.Princy Joice ◽  
Rexlin Sheeba.I

Adders are of fundamental importance in a wide variety of digital systems. This paper presents a novel bit block structure which computes propagate signals as carry strength. Power consumption is one of the most significant parameters of carry select adder.The proposed method aims on GDI(Gate Diffusion Input) Technique. Modified GDI is a novel technique for low power digital circuits design further to reduce the swing degradation problem. This techniques allows reduction in power consumption, carry propagation delay and transistor count of the carry select adder.This technique can be used to reduce the number of transistors compared to conventional CSLA and made comparison with known conventional adders which gives that the usage of carry-strength signals allows high-speed adders to be realised at lower cost as well as consuming lower power than previous designs. Hence, this paper we are concentrating on the area level &we are reducing the power using modified GDI logic.


2020 ◽  
Vol 8 (6) ◽  
pp. 3383-3386

Multipliers play a significant task in digital signal processing applications and application-specific integrated circuits. Wallace tree multipliers provide a high-speed multiplication process with an area-efficient strategy. It is realized in hardware using full adders and half adders. The optimization of adders can further improve the performance of multipliers. Wallace tree multiplier with modified full adder using NAND gate is proposed to achieve reduced silicon area, high speed and low power consumption. The conventional full adder implemented by XOR, AND, OR gates is replaced by the modified full adder realized using NAND gate. The proposed Wallace tree multiplier includes 544 transistors, while the conventional Wallace tree multiplier has 584 transistors for 4-bit multiplication.


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