Gate Diffusion Input Research Articles

High-efficient and error-resilient gate diffusion input-based approximate full adders for complex multistage rapid structures

Two new approximate full adders (FAs) are proposed by the multiplexers (MUXs) and OR gates with the gate diffusion input (GDI) technique. The cells are named GDI-based MUX approximate FAs (GMAFAs), GMAFA1, and GMAFA2. The threshold voltage drop of the GDI-based circuits is solved by carbon nanotube field-effect transistors (CNTFETs) technology and the dynamic threshold (DT) technique. The FAs have accurate Cout, approximate Sum, and a low number of transistors. They are low-power, high-speed, and energy-efficient for ripple-carry adders (RCAs). The GMAFA1 and GMAFA2 have a total area of 0.068 µm2 and 0.119 µm2, respectively, which demonstrate 27.8% and 54.55% improvement in power-delay-area-product (PDAP) in comparison with the best references. The results of error distance (ED), normalized mean error distance (NMED), power signal-to-noise ratio (PSNR), and energy-saving confirm the accuracy of the presented cells for image processing applications.

Low power 10T phase and frequency detector for high frequency phase locked loop

AbstractThe high‐frequency circuits used in communication systems significantly depend on the functioning of the Phase‐Locked Loop (PLL). The power consumption is traded with the performance in the high‐frequency PLL. The proposed robust Phase and Frequency Detector (PFD) has multiple benefits of low‐power and reliable functioning at high frequency. The PFD highly contributes to the stable performance of the PLL, and this work proposes a 10T PFD for low‐power. The proposed PFD employs Gate Diffusion Input (GDI) logic based D‐flip flop and the pass transistor logic in the reset path to reduce power consumption. The PFD uses only 10 transistors, enabling a faster reset path and consuming less power at high frequencies. The 10T PFD was designed using 90 nm CMOS PDKs and simulated using CADENCE Specter for functional verification and performance analysis. The 10T PFD achieved a reset time of 61.4 ps at 3 GHz alongside a power consumption of 189.2 nW. Also, the overall power consumption of PLL using the proposed PFD at 3 GHz was demonstrating the effectiveness of 10T PFD over other conventional PFDs.

Design and Implementation of Low Power Time-To-Digital Converter using MGDI Technique

This paper introduces a novel Time to Digital Converter (TDC) architecture based on the Modified Gate Diffusion Input (MGDI) technique, which is derived from the well-established GDI method. Through the utilization of MGDI-based logic gates and digital circuitry, this innovative approach leads to a substantial reduction in the number of transistors required for implementation. As a result, it offers significant advantages in terms of circuit area, power consumption, and propagation delay, while simultaneously simplifying the complexity of the overall logic design. The functional blocks within the TDC have been optimized to efficiently process an internal clock frequency of 5MHz. This achievement is realized using cutting-edge 90nm MGDI technology, operating at a supply voltage of 1V. Practical implementation of this design can be carried out seamlessly with Cadence Virtuoso tools in the 90nm technology node. In essence, this research effort represents a promising advancement in the realm of time-to-digital conversion. By harnessing the capabilities of MGDI and its transistor-saving attributes, the proposed TDC not only enhances performance but also addresses critical concerns such as power efficiency and chip area utilization. These advancements make it a compelling choice for applications requiring precise time measurements, while the compatibility with contemporary technology nodes ensures its relevance and applicability in modern integrated circuit design.

Imprecise Subtractor Using a New Efficient Approximate-Based Gate Diffusion Input Full Adder for Bioimages Processing.

Approximate circuits are used in fault-tolerance applications, where carbon nanotube field-effect transistor (CNTFET) technology assists to achieve high performance. In this study, a new 8-transistor approximate full adder (FA) is designed and implemented using CNTFETs based on the gate diffusion input (GDI) technique. The FA is implemented in a ripple carry adder (RCA) and a 4-bit inexact subtractor for bioimages difference detection and finally stroke recognition. The non-full-swing outputs of the presented GDI cells are obviated by the dynamic threshold (DT) technique. The presented FA consumes a power of 2.0446 µW, while its power-delay-product (PDP) is 6.4536 fJ. Also, the superior results of peak signal-to-noise ratio (PSNR), power consumption, and PDP of the proposed subtractor are 30.866 dB, 9.642 µW, and 314.907 fJ, respectively. The FA has an area of 0.161 µm2 while the 4-bit subtractor occupies 2.18 µm2. The presented circuits show efficient performance for bioelectronics integrated circuits (ICs).

A Study on the VLSI Implementation of Fingerprint Thinning Processors Using Hybrid GDI Technique

Although the gate-diffusion input (GDI) technique supports low power and small area compared to conventional CMOS standard cell, it is limited to design larger integrated circuits for several reasons. It is difficult to apply the general RTL design flow of building a GDI standard cell library and designing a chip through logic circuit synthesis. In this paper, we proposed the hybrid GDI technique with new structure. We analyzed the problems of the GDI technique, and the analysis extracted the circuit characteristics of previous CMOS and GDI cells and found the cause of the problems. We proposed the synthesis algorithm for the hybrid GDI design. The performance of hybrid GDI was compared and analyzed using synthesized thinning image processor on 1.8 V, 180n CMOS process. The proposed hybrid GDI technique proved that it could be applied to system-on-a-chip (SoC) design with low power and small cell area.

Efficient GDI-based approximate subtractors for change detection in bio-image processing applications

Three new approximate subtractors are presented based on the gate diffusion input (GDI) technique which benefits from the dynamic threshold (DT) technique using carbon nanotube field-effect transistors (CNTFETs) technology. Proposed-1, Proposed-2, and Proposed-3 subtractors have 10, 8, and 6 transistors with a total area of 0.289 μm2, 0.123 μm2, and 0.065 μm2, respectively. In Proposed-1 and Proposed-2, only XOR and F1 gates are used, which respectively have 2 and 4 errors. To solve the non-full-swing defects of these two circuits, only three F2-GDI gates are used in the Proposed-3, which has 4 errors. The Proposed-1 gives 0.25 as error distance (ED) while two other circuits with a lower area have an ED of 0.5. The Proposed-3 has a simple, low-power, and ground-free structure. The subtractors are implemented in an 8 to 4 non-restoring divider in four different configurations including vertical, horizontal, square, and triangular. The drivers based on Proposed-2 and Proposed-3 are the best circuits with average power-delay-product (PDP) savings of 68.16% and 57.43%, respectively. Finally, the dividers are used in the change detection of medical images, where, the proposed circuits show better circuitry performance and image quality production.

Single-sided gate-wrap-around CNTFET SRAM cell for utilization in reliable IoT-based platforms

This paper proposes a novel design of an 11-transistor SRAM bit-cell with a single-ended structure and memory mini-array with the bit-interleaving architecture support using the gate-diffusion input (GDI) method based on the gate-wrap-around (GWA) CNTFETs technology. The cell core of the suggested design is composed of a robust cross-coupled structure of two asymmetric inverters based on circuit-level methodologies. The proposed bit-cell scheme exhibits significant features such as improved write-ability, read data stability, and reduced leakage/short-circuit power due to the asymmetric write-assist method and inverter gates with stacked transistors, respectively. The simulation analysis has been done based on criteria such as static noise margins (SNMs), power-delay product (PDP), and the electrical quality/yield-based figure of merits (FoMs) in write/hold/read operation cycles. The suggested SRAM bit-cell demonstrates the best results with an average of 9.36 %, 48.53 %, and 22.82 %, respectively, for FoMs against other SRAM bit-cell schemes. The Monte-Carlo simulations in the 16-nm node show better results for the proposed bit-cell in the energy and failure probability per operation cycles than similar designs, with the best performance on average of 27 % and 8 %, respectively.Finally, to investigate the effectiveness of the suggested memory cell in the real application domain, an on-chip scaled power supply memory architecture for storing digital data based on quick response (QR) code using the proposed hardware algorithm is evaluated. Our results certify that the suggested memory array configuration in comprehensive FoMs based on quality and hardware efficiency metrics shows better results than the counterpart memory architecture.

High Efficient GDI-CNTFET-Based Approximate Full Adder for Next Generation of Computer Architectures

Approximate computing (AC) is an emerging technique in arithmetic circuits. In this letter, a new AC-based full adder (FA) circuit is presented with 12 transistors, 150mm]Please confirm or add details for any funding or financial support for the research of this article. -160mm]If you haven’t done so already, please make sure you have submitted a video graphical abstract (GA) for your paper, along with a caption and overlay image. The GA will be displayed on your articles abstract page on IEEE Xplore. Note that captions cannot exceed 1800 characters (including spaces). Overlay images are usually a screenshot of your video that best represents the video. This is for readers who may not have access to video-viewing software. 0.239 <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$\mu \text{m}^{2}$ </tex-math></inline-formula> of area, and two errors in the outputs. In the proposed FA, the gate diffusion input (GDI) and dynamic-threshold (DT) techniques are applied using the carbon nanotube field-effect transistor (CNTFET) technology. Accuracy metrics, such as normalized mean error distance (NMED) and mean relative error distance (MRED) along with circuitry parameters of power-delay-product (PDP), energy-delay-product (EDP), and power-delay-area-product (PDAP), confirm the efficiency of the proposed FA for complex structures. The proposed FA is embedded in a ripple carry adder (RCA) by various numbers of approximate bits (NABs), and then the accuracy and circuitry parameters are extracted. Compared to the state-of-the-art designs, the high-efficient behavior of the proposed FA is proved when it is used in image processing applications.

Design and memory optimization of hybrid gate diffusion input numerical controlled oscillator

The numerically controlled oscillator (NCO) is one of the digital oscillator signal generators. It can generate the clocked, synchronous, discrete waveform, and generally sinusoidal. Often NCOs care utilized in the combinations of digital to analog converter (DAC) at the outputs for creating direct digital synthesizer (DDS). The network on chips (NOCs) are utilized in various communication systems that are fully digital or mixed signals such as synthesis of arbitrary wave, precise control for sonar systems or phased array radar, digital down/up converters, all the digital phase locked loops (PLLs) for cellular and personal communication system (PCS) base stations and drivers for acoustic or optical transmissions and multilevel phase shift keying/frequency shift keying (PSK/FSK) modulators or demodulators (modem). The basic architecture of NCO will be enhanced and improved with less hardware for facilitating complete system level support to various sorts of modulation with minimum FPGA resources. In this paper design and memory optimization of hybrid gate diffusion input (GDI) numerically controlled oscillator based on field programmable gate array (FPGA) is implemented. compared with NCO based 8-bit microchip, memory optimization of hybrid GDI numerically controlled oscillator based on FPGA gives effective outcome in terms of delay, metal-oxide-semiconductor field-effect transistors (MOSFET’s) and nodes.

A high‐efficient imprecise discrete cosine transform block based on a novel full adder and Wallace multiplier for bioimages compression

SummarySophisticated systems take advantage of approximate circuits for energy management. A gate‐level structure is introduced to make a novel imprecise full adder (FA) cell by the gate diffusion input (GDI) strategy. The carbon nanotube field‐effect transistor (CNTFET) technology lowers the FA power, and the swing issue is resolved by the dynamic threshold (DT) technique. The FA specifications are 10 transistors, two internal nodes, 0.191‐μm2 area, three errors, and an error rate (ER) of 37.5%. Some inputs are directly passed to the final stage of the FA to reduce the delay and dynamic power. The FA is used in three 4:2 compressors with 12, 16, and 20 transistors, respectively. The compressors are based on the modified stacking concept to attain low power, small area, and high speed. The compressors are used up in the partial product reduction tree (PPRT) of a new 8‐bit inexact multiplier. Regarding the multiplier, the power–delay product (PDP) is decreased by 25.21%, and the normalized mean error distance (NMED) shows high accuracy. An imprecise discrete cosine transform (DCT) is implemented by the multiplier for image compression, and compared with the literature, the peak signal‐to‐noise ratio (PSNR) and structural similarity index metric (SSIM) are amended by 8.26% and 7.29%, respectively.

The design of a low-power 4-bit barrel shifter for a current steering DAC using optimized multiplexers in 65 nm technology

CMOS technology scaling has paved the way for a faster and more complex integration. Low-power techniques have become crucial because of the demand for low power consumption and high speed. The main objective of this research is to utilize low-power techniques to implement a 4-bit barrel shifter that can shift or rotate data using any number of bits within a single cycle. Gate Diffusion Input (GDI), modified GDI, and full-swing GDI logic have been employed to implement a 2:1 multiplexer, among which the modified GDI-based multiplexer stands out because of its minimal power consumption. Consequently, a 4-bit barrel shifter is implemented using a modified GDI-based multiplier. All designs and simulations were performed using the Cadence Virtuoso tool in UMC 65 nm technology. This technology enables the accurate analysis and assessment of the designed barrel shifter, considering the characteristics and limitations of the 65 nm process. This study focused on leveraging low-power techniques to implement a 4-bit barrel shifter to address the industry's demand for power-efficient solutions. The modified GDI-based multiplexer is a promising choice that provides a balance between low power consumption and high performance. The use of advanced design tools and selected technology further ensures accurate simulations and evaluations of the proposed design.

Review on Low Power Alu Design Using Various Techniques

VLSI technology has advanced significantly, and there arenumerous effective methods for creating VLSI circuits. PTL, GDI(Gate Diffusion Input) methods, and CMOS are a few of the styles.The weaknesses of CMOS and PTL approaches can be eliminatedby using the GDI technique to create low-power digitalcombinatorial circuits. This method maintains a low level of logicdesign complexity while lowering the amount of power consumed,propagation latency, and size of digital circuits. This paper discussesthe benefits and limitations of GDI compared to CMOS design bycomparing the various approaches with respect to layout area,transistor count, latency, and power dissipation.

Mitigation of Critical Delay in the Carry Skip Adders Using FinFET 18nm Technology

In this paper optimization of full adder in 3-dimensional (3-D) using Fin Field Effect Transistor (FinFET) with Gate Diffusion Input (GDI) is proposed to optimize critical delay, power. FinFET technology is more suitable for below 10nm technology process. The major aim of this work is to indemnify significant factor in adder structure i.e. critical delay. Pipelining architecture is enforced to accomplish the objective with the aid of FinFET 18nm technology. The structure is optimized to get the minimum delay confinement. Suggested design needs less logic resources. The outcomes are validated using FPGA synthesis methods. By applying the FinFET technique, we developed adder topology yielding up to 90% performance improvement with respect to delay, power and area compared to the conventional adders. The simulation was carried out with low power cds ff mpt PDK. The study also includes a carry skip adder design for FPGA implementation.

Modified Dual Mode Transmission Gate Diffusion Input Logic for Improving Energy Efficiency

This paper presents a modified energy-efficient Dual Mode Transmission Gate Diffusion Input (DMTGDI) design and is termed as M-DMTGDI. A contention issue in dynamic mode operation of existing DMTGDI design and DMPL design is identified and illustrated through mathematical formulation and simulations. To resolve this concern, the pre-charge/pre-discharge transistor in existing DMTGDI design is replaced by dual mode inverter in the proposal. The functional verification and performance comparison of NAND, NOR, XOR gates and 1-bit full adder based on proposed M-DMTGDI is carried out using 90 nm BSIM4 model card for bulk CMOS using Symica DE tool. The performance of the circuits is evaluated in terms of power, delay and Power Delay Product (PDP) in both static and dynamic modes. The variation of PDP with the ratio of the time the circuit is designed to run in dynamic mode against static mode is also investigated to analyze the energy efficiency of the M-DMTGDI design. The proposed approach offers maximum PDP reduction of 33.52%, 99.39% and 96.61% for 2-input gates as compared to their footed DML, DMPL and DMTGDI counterparts, respectively. The reduction in PDP is quite significant in 1-bit full adder circuit where the corresponding values are 94.18%, 99.41% and 99.79%, respectively.

A High-Performance Full Adder Design with Low Area, Power and Delay

A new one-bit adder architecture is described that may be used with a variety of logics, including Static CMOS, transmission gates, the Transmission Full Adder (TFA), and the New-14T Gate Diffusion Input Method (GDI). The Modified Gate Diffusion Input Method (MGDI) is used to suggest a novel structure design for a full adder. The full adder circuit is used in the Modified Gate Diffusion Input Method (MGDI), and experimental results demonstrate its superior performance compared to traditional methods. Full adders with multistage arrangements are also considered, as their performance may differ from that of a 1-bit full adder. As a result, two applications of multistage full adder structures, the ripple carry adder (RCA) and 6:2 compressor are used to analyze the findings. The power, area and delay are reduced by around 40% when compared to the existing methods. All the designs are simulated using Tanner EDA. The proposed full adder has a lower transistor count (6 or 7 transistors), lower power dissipation, and less delay than previous designs, according to simulation data.

Voltage over‐scaling CNT‐based 8‐bit multiplier by high‐efficient GDI‐based counters

A new low-power and high-speed multiplier is presented based on the voltage over scaling (VOS) technique and new 5:3 and 7:3 counter cells. The VOS reduces power consumption in digital circuits, but different voltage levels of the VOS increase the delay in different stages of a multiplier. Hence, the proposed counters are implemented by the gate-diffusion input technique to solve the speed limitation of the VOS-based circuits. The proposed GDI-based 5:3 and 7:3 counters save power and reduce the area by 2x and 2.5x, respectively. To prevent the threshold voltage (Vth) drop in the suggested GDI-based circuits, carbon nanotube field-effect transistor (CNTFET) technology is used. In the counters, the chirality vector and tubes of the CNTFETs are properly adjusted to attain full-swing outputs with high driving capability. Also, their validation against heat distribution under different time intervals, as a major issue in the CNTFET technology is investigated, and their very low sensitivity is confirmed. The low complexity, high stability and efficient performance of the presented counter cells introduce the proposed VOS-CNTFET-GDI-based multiplier as an alternative to the previous designs.

LOW POWER OPTIMIZATION OF FULL ADDER CIRCUIT BASED ON GDI LOGIC FOR BIOMEDICAL APPLICATIONS

Advanced Electronic Devices have recently become more prevalent, designers have opted for low power, quick speed, and compact designs and processes. Even though there are numerous design methodologies currently in use for VLSI system design optimization, very few design techniques produce solutions that are optimally optimal. GDI-based circuits are becoming increasingly important since they use less space, power, and energy. The GDI technique ensures minimal propagation delay, power, and area in low-power design strategies. For 45nm technology, the Cadence Virtuoso EDA tool is utilised to determine delay and power. The proposed designs examination of delay and power performance at 1.0V voltage produced positive findings. The Gate Diffusion Input concept serves as the foundation for the proposed design in this work. In order to achieve a full voltage swing of the output, a 1-bit full adder circuit design using GDI is demonstrated in this work. The GDI with the Full Swing Technique is presented in this work. Applying the suggested way to a 45nm complete adder from 14 Transistors. It is evident from the obtained simulation results that the suggested design uses the least power and the least amount of delay when compared to other full adder circuits that are already in use. Consequently, compared to previous full adder GDI circuit designs, the output voltage swing is in full and the overall power-delay product is improved by 60 percent.

One‐sided 10T static‐random access memory cell for energy‐efficient and noise‐immune internet of things applications

AbstractThis paper presents a one‐sided 10‐transistors static‐random access memory (SRAM) cell appropriate for the internet of things (IoT) applications in which energy‐efficient SRAM cells are necessary to raise the battery lifetime. The bit‐cell core of the proposed SRAM cell is composed of two inverters with different structures based on the gate‐wrap‐around (GWA) carbon nanotube (CNT)‐gate‐diffusion input (GDI) technique and only one‐bit line to perform both read and write operations to minimize active power consumption. The proposed bit‐cell uses a transmission gate network and write‐assist schemes to significantly improve the write‐ability and stack read‐decoupling technique to enhance hold‐/read‐stability. Moreover, a memory mini‐array has been implemented using the proposed cell along with all the principal circuitries. Extensive Monte Carlo (MC) simulations show that write/hold/read static noise margins (SNMs) are improved by about 1.252, 1.196, and 1.152 times, respectively. Also, the results of evaluating the write‐ and read‐yield parameters for the proposed SRAM bit‐cell are about 22% and 13% better than counterpart bit‐cell designs, respectively. In addition, the bit error rate (BER) and energy dissipation parameters for the proposed memory cell are almost 61% and seven times higher than the studied SRAM bit‐cell in the same simulation process. Finally, to evaluate the effectiveness of the proposed SRAM bit‐cell in the real‐world application, a memory array architecture with an online (or off‐chip) adaptive power supply voltage based on a hardware algorithm for storing digital images at a minimum energy dissipation is proposed. Our simulation results emphasize that the proposed memory array can be a good candidate for energy‐efficient and noise‐immunity IoT platforms.

Improved Read/Write Stability-Based Level Shift 5T Ternary SRAM Cell Design Using Enhanced Gate Diffusion Input BWGCNTFET

Nowadays, CNTFET introduced the complexity of SRAM design along with the stability. To overcome these complexities, an enhanced Gate Diffusion Input technique-based Ballistic wrap gate CNTFET (EGDI-BWGCNTFET) technology with ternary static random-access memory (T-SRAM) is proposed in this paper. The aim of the proposed technique is “to give higher stability with less stagnant power consumption, voltage drop and store appropriate read/write value of the SRAM cells”. Here, level shift 5T ternary SRAM cell design using Enhanced Gate Diffusion Input Ballistic wrap gate CNTFET (level shift EGDI-BWGCNTFET 5T-ternary SRAM) is proposed for improving read and write stability. It uses two cross-coupled EGDI-BWGCNTFET ternary inverter, which is used for data storage elements along with one access transistor which is connected with bit line (BL) and word line (WL) with minimum supply voltage resulting in leakage current that is decreased. By this, proposed method reduces delay in the write cycles and read cycles. It provides good read static noise margin (RSNM) and controls precharge voltage. The proposed level shift EGDI-BWGCNTFET 5T-ternary SRAM is done in HSPICE platform. The performance of the proposed level shift EGDI-BWGCNTFET 5T-ternary SRAM design is measured in terms of lower Read Delay 23.25%, 22.94%, 18.38%, 23.97%, lower Write Delay 33.92%, 28.94%, 42.83%, 31.98% compared with the existing methods, such as 8T CNTFET-Ternary SRAM, 24T CNTFET-2Ternary SRAM, 18T CNTFET-Ternary SRAM and 17T CNTFET-Ternary SRAM, respectively.

Design of FinFET based low power, high speed hybrid decoder for SRAM

This paper proposes a novel FinFET based hybrid logic design for line decoders, which comprises of transmission gate logic (TGL), modified gate diffusion input (MGDI) logic and conventional NAND based FinFET logic. The 2–4 FinFET based decoder is designed using two topologies: (i) a 14- transistor topology for low power dissipation and lesser area and (ii) a 15-transitor topology for high-speed performance. Using the two topologies mentioned above, both inverting and non-inverting decoders of size 2–4 and 4–16 are designed. SPICE simulations of the proposed decoders are done at 45 nm CMOS and FinFET technologies and compared with different logic styles such as conventional logic, MGDI, mixed logic, and mixed MGDI logic at different frequencies with varying supply voltages and the proposed design outperforms other logic styles compared. The proposed FinFET hybrid decoder exhibits 6% and 77% lower power; 11.6% and 61.26% lower delay; 17% and 91.10% lower PDP respectively compared to the FinFET mixed decoder and CMOS hybrid decoder.