Efficient Diminished-1 Modulo (2n+1) Adder Using Parallel Prefix Adder

2020 ◽  
Vol 29 (12) ◽  
pp. 2050186
Author(s):  
Subodh Kumar Singhal ◽  
B. K. Mohanty ◽  
Sujit Kumar Patel ◽  
Gaurav Saxena

Parallel prefix adder (PPA) is the core component of diminished-1 modulo ([Formula: see text]) adder structure. In this paper, group-carry selection logic based PPA design is proposed and it is free from redundant logic operations which otherwise present in the existing PPA design based on group sum selection logic. Further, the logic expression of pre-processing unit of PPA is also presented in a simplified form to save some logic resources. The proposed PPA design for bit-width 32-bit involves 26.1% less area, consumes 28.4% less power and marginally higher critical-path delay than the existing PPA design. An efficient diminished-1 modulo ([Formula: see text]) adder structure is presented using proposed PPA design and modified carry computation algorithm of existing design. The proposed diminished-1 modulo ([Formula: see text]) adder structure for bit-width 32-bit offers a saving of 25.5% in area-delay-product (ADP) and 24.1% in energy-delay-product (EDP) than the best of the existing modulo adder structure.

Author(s):  
Kenta Shirane ◽  
Takahiro Yamamoto ◽  
Hiroyuki Tomiyama

In this paper, we present a case study on approximate multipliers for MNIST Convolutional Neural Network (CNN). We apply approximate multipliers with different bit-width to the convolution layer in MNIST CNN, evaluate the accuracy of MNIST classification, and analyze the trade-off between approximate multiplier’s area, critical path delay and the accuracy. Based on the results of the evaluation and analysis, we propose a design methodology for approximate multipliers. The approximate multipliers consist of some partial products, which are carefully selected according to the CNN input. With this methodology, we further reduce the area and the delay of the multipliers with keeping high accuracy of the MNIST classification.


2018 ◽  
Vol 7 (2.16) ◽  
pp. 94
Author(s):  
Abhishek Choubey ◽  
SPV Subbarao ◽  
Shruti B. Choubey

Multiplication is one of the most an essential arithmetic operation used in numerous applications in digital signal processing and communications. These applications need transformations, convolutions and dot products that involve an enormous amount of multiplications of an operand with a constant. Typical examples include wavelet, digital filters, such as FIR or IIR. However, multiplier structures have relatively large area-delay product, long latency and significantly high power consumption compared to other the arithmetic structure. Therefore, low power multiplier design has been always a significant part of DSP structure for VLSI design. The Booth multiplier is promising as the most efficient amongst the others multiplier as it reduces the complexity of considerably than others. In this paper, we have proposed Booth-multiplier using seamless pipelining. Theoretical comparison results show that the proposed Booth multiplier requires less critical path delay compared to traditional Booth multiplier. ASIC simulation results show proposed radix-16 Booth multiplier 13% less critical path delay for word width n=16 and 17% less critical path delay compared for bit width n=32 to best existing radix-16 Booth multiplier. 


Electronics ◽  
2021 ◽  
Vol 10 (5) ◽  
pp. 630
Author(s):  
Padmanabhan Balasubramanian ◽  
Raunaq Nayar ◽  
Douglas L. Maskell

This article describes the design of approximate array multipliers by making vertical or horizontal cuts in an accurate array multiplier followed by different input and output assignments within the multiplier. We consider a digital image denoising application and show how different combinations of input and output assignments in an approximate array multiplier affect the quality of the denoised images. We consider the accurate array multiplier and several approximate array multipliers for synthesis. The multipliers were described in Verilog hardware description language and synthesized by Synopsys Design Compiler using a 32/28-nm complementary metal-oxide-semiconductor technology. The results show that compared to the accurate array multiplier, one of the proposed approximate array multipliers viz. PAAM01-V7 achieves a 28% reduction in critical path delay, 75.8% reduction in power, and 64.6% reduction in area while enabling the production of a denoised image that is comparable in quality to the image denoised using the accurate array multiplier. The standard design metrics such as critical path delay, total power dissipation, and area of the accurate and approximate multipliers are given, the error parameters of the approximate array multipliers are provided, and the original image, the noisy image, and the denoised images are also depicted for comparison.


2008 ◽  
Vol 24 (1-3) ◽  
pp. 203-222 ◽  
Author(s):  
Kyriakos Christou ◽  
Maria K. Michael ◽  
Spyros Tragoudas

2020 ◽  
Vol 2020 ◽  
pp. 1-13
Author(s):  
Mohd Tausif ◽  
Ekram Khan ◽  
Mohd Hasan ◽  
Martin Reisslein

This paper proposes and evaluates the LFrWF, a novel lifting-based architecture to compute the discrete wavelet transform (DWT) of images using the fractional wavelet filter (FrWF). In order to reduce the memory requirement of the proposed architecture, only one image line is read into a buffer at a time. Aside from an LFrWF version with multipliers, i.e., the LFr WF m , we develop a multiplier-less LFrWF version, i.e., the LFr WF ml , which reduces the critical path delay (CPD) to the delay T a of an adder. The proposed LFr WF m and LFr WF ml architectures are compared in terms of the required adders, multipliers, memory, and critical path delay with state-of-the-art DWT architectures. Moreover, the proposed LFr WF m and LFr WF ml architectures, along with the state-of-the-art FrWF architectures (with multipliers (Fr WF m ) and without multipliers (Fr WF ml )) are compared through implementation on the same FPGA board. The LFr WF m requires 22% less look-up tables (LUT), 34% less flip-flops (FF), and 50% less compute cycles (CC) and consumes 65% less energy than the Fr WF m . Also, the proposed LFr WF ml architecture requires 50% less CC and consumes 43% less energy than the Fr WF ml . Thus, the proposed LFr WF m and LFr WF ml architectures appear suitable for computing the DWT of images on wearable sensors.


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