A New-High Speed-Low Power-Carry Select Adder Using Modified GDI Technique

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.

Author(s):  
Merrin Mary Solomon ◽  
Neeraj Gupta ◽  
Rashmi Gupta

Full adder is an important component for designing a processor. As the complexity of the circuit increases, the speed of operation becomes a major concern. Nowadays there are various architectures that exist for full adders. In this paper we will discuss about designing a low power and high speed full adder using Gate Diffusion Input technique. GDI is one of the present day methods through which one can design logical circuits. This technique will reduce power consumption, propagation delay, and area of digital circuits as well as maintain low complexity of logic design. The performance of the proposed design is compared with the contemporary full adder designs.


Author(s):  
Mohsen A. M. El-Bendary ◽  
◽  
M. Ayman ◽  

Full Swing Gate Diffusion Input (FS-GDI) approach is power effective approach for realizing the different logic gates. In this research, this approach is utilized for realizing different four ALU design using 45nm and 130nm technologies. Also, the different low power VLSI logic styles and related past works are discussed with considering the 45nm and 65nm technologies for implementing various circuits for studying the technology size impact. The performance of the proposed ALU design is evaluated through power consumption, propagation delay and number of transistors. The variation of the ALU performance due to the used 45nm and 130nm technologies has been studied. The simulation is carried out utilizing Cadence Virtuoso simulator. The simulation experiments revealed the energy of the 4-bit ALU reduced by 32% compared to CMOS-based design and area of the digital circuits reducing. Regarding the different nano technologies, 45nm technology provides lower power consumption and delay time deceasing compared to ALU unit by 130nm technology. The presented approach of low hardware complexity achieves simplicity of the required ALU hardware through reducing the number of transistors.


2019 ◽  
Vol 3 (3) ◽  
pp. 19-27
Author(s):  
Mohsen Sadeghi ◽  
Mahya Zahedi ◽  
Maaruf Ali

This article presents a low power consumption, high speed multiplier, based on a lowest transistor count novel structure when compared with other traditional multipliers. The proposed structure utilizes 4×4-bit adder units, since it is the base structure of digital multipliers. The main merits of this multiplier design are that: it has the least adder unit count; ultra-low power consumption and the fastest propagation delay in comparison with other gate implementations. The figures demonstrate that the proposed structure consumes 32% less power than using the bypassing Ripple Carry Array (RCA) implementation. Moreover, its propagation delay and adder units count are respectively about 31% and 8.5% lower than the implementation using the bypassing RCA multiplier. All of these simulations were carried out using the HSPICE circuit simulation software in 0.18 μm technology at 1.8 V supply voltage. The proposed design is thus highly suitable in low power drain and high-speed arithmetic electronic circuit applications.


Compressors are the fundamental building blocks to construct Data Processing arithmetic units. A novel 3-2 Compressor is presented in this paper which is designed by Mixed logic design style. In addition to small size transistors and reduced transistor activity compared to conventional CMOS (Complementary Metal Oxide Semiconductor) gates, it provides the priority between the High logic and Low logic for the computation of the output. Various logic topologies are used to design the 3-2 compressor like High-Skew(Hi-Skew), Low-Skew(Li-Skew), TGL (Transmission Gate Logic) and DVL (Dual value Logic). This new approach gives the better operating speed, low power consumption compared to conventional logic design by reducing the transistors activity, improving the driving capability and reduced input capacitance with skew gates. Especially the Mixed logic style-3 provides 92.39% average power consumption and Propagation Delay of 99.59% at 0.8v. The H-SPICE simulation tool is used for construction and evaluation of compressor logic at different voltages. 32nm model file is used for MOS transistors


2021 ◽  
Author(s):  
Kalaiyarasi.D ◽  
Pritha.N ◽  
Srividhya.G ◽  
Padmapriya.D

The multiplier is a fundamental building block in most digital ICs’ arithmetic units. The multiplier architecture in modern VLSI circuits must meet the main parameters of low power, high speed, and small area requirements. In this paper, a 4-bit multiplier is constructed using the Dadda algorithm with enhanced Full and Half adder blocks to achieve a smaller size, lower power consumption, and minimum propagation delay. The Dadda Algorithm-designed multiplier is used in the first phase to reduce propagation delay while adding partial products in three stages provided by AND Gates. In the second phase, each stage of the Dadda tree algorithm is built with an enhanced Full and half adders to reduce the design area, propagation delay, and power consumption while still meeting the requirements of the current scenario by using MUX logic. In an average of Conventional array Multipliers, the proposed Dadda multiplier achieved an 84.68% reduction in delay, 70.89% reduction in power, 84.68% increase in Maximum Usable Frequency (MUF), and 95.55% reduction in Energy per Samples (EPS).


Author(s):  
B. FRANCIS ◽  
Y. APPARAO ◽  
B. CHINNARAO

This paper enumerates low power, high speed design of flip-flop having less number of transistors and only one transistor being clocked by short pulse train which is true single phase clocking (TSPC) flip-flop. Compared to Conventional flip-flop, it has 5 Transistors and one transistor clocked, thus has lesser size and lesser power consumption. It can be used in various applications like digital VLSI clocking system, buffers, registers, microprocessors etc. The analysis for various flip flops and latches for power dissipation and propagation delays at 0.13μm and 0.35μm technologies is carried out. The leakage power increases as technology is scaled down. The leakage power is reduced by using best technique among all run time techniques viz. MTCMOS. Thereby comparison of different conventional flip-flops, latches and TSPC flip-flop in terms of power consumption, propagation delays and product of power dissipation and propagation delay with SPICE simulation results is presented.


Author(s):  
A. Suresh Babu ◽  
B. Anand

: A Linear Feedback Shift Register (LFSR) considers a linear function typically an XOR operation of the previous state as an input to the current state. This paper describes in detail the recent Wireless Communication Systems (WCS) and techniques related to LFSR. Cryptographic methods and reconfigurable computing are two different applications used in the proposed shift register with improved speed and decreased power consumption. Comparing with the existing individual applications, the proposed shift register obtained >15 to <=45% of decreased power consumption with 30% of reduced coverage area. Hence this proposed low power high speed LFSR design suits for various low power high speed applications, for example wireless communication. The entire design architecture is simulated and verified in VHDL language. To synthesis a standard cell library of 0.7um CMOS is used. A custom design tool has been developed for measuring the power. From the results, it is obtained that the cryptographic efficiency is improved regarding time and complexity comparing with the existing algorithms. Hence, the proposed LFSR architecture can be used for any wireless applications due to parallel processing, multiple access and cryptographic methods.


Author(s):  
Ahmed K. Jameil ◽  
Yasir Amer Abbas ◽  
Saad Al-Azawi

Background: The designed circuits are tested for faults detection in fabrication to determine which devices are defective. The design verification is performed to ensure that the circuit performs the required functions after manufacturing. Design verification is regarded as a test form in both sequential and combinational circuits. The analysis of sequential circuits test is more difficult than in the combinational circuit test. However, algorithms can be used to test any type of sequential circuit regardless of its composition. An important sequential circuit is the finite impulse response (FIR) filters that are widely used in digital signal processing applications. Objective: This paper presented a new design under test (DUT) algorithm for 4-and 8-tap FIR filters. Also, the FIR filter and the proposed DUT algorithm is implemented using field programmable gate arrays (FPGA). Method: The proposed test generation algorithm is implemented in VHDL using Xilinx ISE V14.5 design suite and verified by simulation. The test generation algorithm used FIR filtering redundant faults to obtain a set of target faults for DUT. The fault simulation is used in DUT to assess the benefit of test pattern in fault coverage. Results: The proposed technique provides average reductions of 20 % and 38.8 % in time delay with 57.39 % and 75 % reductions in power consumption and 28.89 % and 28.89 % slices reductions for 4- and 8-tap FIR filter, respectively compared to similar techniques. Conclusions: The results of implementation proved that a high speed and low power consumption design can be achieved. Further, the speed of the proposed architecture is faster than that of existing techniques.


Nanophotonics ◽  
2020 ◽  
Vol 10 (2) ◽  
pp. 937-945
Author(s):  
Ruihuan Zhang ◽  
Yu He ◽  
Yong Zhang ◽  
Shaohua An ◽  
Qingming Zhu ◽  
...  

AbstractUltracompact and low-power-consumption optical switches are desired for high-performance telecommunication networks and data centers. Here, we demonstrate an on-chip power-efficient 2 × 2 thermo-optic switch unit by using a suspended photonic crystal nanobeam structure. A submilliwatt switching power of 0.15 mW is obtained with a tuning efficiency of 7.71 nm/mW in a compact footprint of 60 μm × 16 μm. The bandwidth of the switch is properly designed for a four-level pulse amplitude modulation signal with a 124 Gb/s raw data rate. To the best of our knowledge, the proposed switch is the most power-efficient resonator-based thermo-optic switch unit with the highest tuning efficiency and data ever reported.


Sensors ◽  
2021 ◽  
Vol 21 (7) ◽  
pp. 2260
Author(s):  
Khuram Shehzad ◽  
Deeksha Verma ◽  
Danial Khan ◽  
Qurat Ul Ain ◽  
Muhammad Basim ◽  
...  

A low power 12-bit, 20 MS/s asynchronously controlled successive approximation register (SAR) analog-to-digital converter (ADC) to be used in wireless access for vehicular environment (WAVE) intelligent transportation system (ITS) sensor based application is presented in this paper. To optimize the architecture with respect to power consumption and performance, several techniques are proposed. A switching method which employs the common mode charge recovery (CMCR) switching process is presented for capacitive digital-to-analog converter (CDAC) part to lower the switching energy. The switching technique proposed in our work consumes 56.3% less energy in comparison with conventional CMCR switching method. For high speed operation with low power consumption and to overcome the kick back issue in the comparator part, a mutated dynamic-latch comparator with cascode is implemented. In addition, to optimize the flexibility relating to the performance of logic part, an asynchronous topology is employed. The structure is fabricated in 65 nm CMOS process technology with an active area of 0.14 mm2. With a sampling frequency of 20 MS/s, the proposed architecture attains signal-to-noise distortion ratio (SNDR) of 65.44 dB at Nyquist frequency while consuming only 472.2 µW with 1 V power supply.


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