Search

In this study, a three-level static RAM cell with a single BL based on 16 nm BWG CNFET technology is proposed for use in high-performance IoT platforms. The proposed memory structure in a bit-interleaved architecture compatible design consists of a standard triple buffer gate (STB) based on the BWG CN-TGDI method and a pair of transmission gates as an access network. In the STB cell structure, the threshold voltage calibration by the flat band voltage parameter of the CNTs has been used to improve the static noise margin at logic level '1'. In addition, pseudo-resistor and stacked transistor structures have been used to control the single static current path during logic level '1' generation and cell leakage current, respectively. The simulation results based on the Monte Carlo method show that the hardware performance parameters PDP and EDP for the proposed design have been improved by 38.8% and 31%, respectively, compared to the counterpart structure. Moreover, the proposed architecture has shown a more reasonable result in terms of noise immunity than the best-performing design by 1.93 times. Finally, to investigate a real-world application, the triple memory structure has been used to store the colored QR code image with the data content of three values using the proposed hardware algorithm. The obtained results for the quality evaluation metrics, PSNR and MSSIM, emphasize the suitability of the proposed memory architecture for the development of next-generation SoCs. [ABSTRACT FROM AUTHOR]

This 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. [ABSTRACT FROM AUTHOR]

Gate diffusion input (GDI) method using a simple cell makes it possible to design low-power logic gates with reduced chip area and less complexity. In this work, a novel design of single-bit optimized reversible logic-based magnitude arithmetic unit (RMAU) circuit, using appropriate standard reversible gates with carbon nanotube (CNT) field-effect transistors (CNTFETs), based on modified-GDI (m-GDI) method for nanoscales is presented. In order to optimize the performance of the proposed circuit, and to achieve minimum power consumption and propagation delay, transistor sizes are adjusted using the non-dominated sorting genetic algorithm II (NSGA-II) in MATLAB tool. The simulation results show improvement in evaluating the figure of merits in worst-case delay and power consumption of the proposed optimized arithmetic unit, in comparison with a non-optimized RMAU circuit using a similar design method but counterpart structures. The effects of different process parameters (such as the diameter of CNTs) and voltage and temperature (PVT) variations are extensively evaluated by the Monte Carlo procedure in standard 32 nm technology utilizing the Synopsys HSPICE simulator. According to the outcomes obtained, the proposed optimized RMAU circuit is robust against PVT variations and noise-tolerable criterions, compared to those competitors with similar design in non-optimized conditions. The proposed optimized and non-optimized circuits were used in image processing as real environment assessments, and results depicted their excellent ability in being implemented in various large reversible-based applications, such as future generations of FPGA chips and CNTFET-based computers. [ABSTRACT FROM AUTHOR]

In this work, CNTFET-based GDI (CNT-GDI) and QCA-based GDI (QCA-GDI) methods (CNT/QCA-GDI) for designing unique ultra-efficient analogue and logical blocks in voltage-mode fuzzy and quantum systems are presented. Extensive Monte-Carlo simulations by using Synopsys H-SPICE simulator at 16 nm technology demonstrate that the analogue blocks improve considerably in term of performance, absolute error and energy consumption in the presence of compact variations in compared to their counterparts. Also, the logical blocks have advantages including fast response, high polarity and lower power-consumption achieved by the QCADesigner and QCAPro tools at 18 nm in contrast to the similar designs. As applications, the half wave rectifier (HWR) and full-wave rectifier (FWR) by employing the proposed methods in two technologies are implemented. The results show improvement for the proposed circuits with correct function and very high robustness under major variations in contrast to state-of-the art rectifier architectures at similar conditions. Consequently, the proposed methods are appropriate for designing integrated circuits (ICs) with higher capacity and energy-efficient for the emerging nano-technologies. [ABSTRACT FROM AUTHOR]

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. [ABSTRACT FROM AUTHOR]

In this work, unique characteristics of carbon nano-tube field effect transistor (CNTFET) are used to propose a universal cell with a simple architecture based on the binary modified gate-diffusion input (m-GDI) method for designing fundamental gates in the voltage-mode multiple-valued logic (MVL) with any arbitrary number of logic levels for processing at nano-scales. The results of the simulations confirm more energy-efficiency, larger noise margins and lower sensitivity of the proposed designs in different logic levels as compared with the state-of-the-art designs. The effects of the process, voltage and temperature (PVT) variations are extensively evaluated by Monte–Carlo simulation. According to the results, the proposed designs are robust against PVT variations and noise. The proposed structure is applied to the MVL-based image processing. The results show that the output images of the proposed MVL-based inexact gates have an appropriate quality in compare with the images generated by the other similar exact gates. [ABSTRACT FROM AUTHOR]

In this work, a novel architecture is proposed for designing the clocked master-slave TFF (M/S-TFF) based on modified gate-diffusion input (m-GDI) method. By noting that we used clocked phase scheme or feedback input technique in designing the M/S-TFF circuit. The advantages of the proposed scheme can be cited as reduce the number of required transistors, lower power consumption-propagation delay product ( PDP ) in all activity factors and layout area in comparison with similar state-of-the art designs. More importantly, Monte-Carlo simulations confirm proposed topology gains substantial variation tolerance with a substantial small standard deviation and considerable lower variability percentage in metrics than other schemes in same technology. At the end, the presented static frequency divider (SFD) using proposed M/S-TFF, works at wider frequency range with 0.198 milli-Watt (mW) power dissipation at the maximum operating frequency ( f max . ) about 46 Giga-Hertz (GHz) under 0.9 Volt supply voltage. Therefore, using the proposed scheme can be improved in data storing elements, prescaler block in phase-locked loop (PLL) chips for future of generation communication networks like: fifth generation (5G) and microprocessors performance. [ABSTRACT FROM AUTHOR]

The conventional complementary metal-oxide semiconductor (CMOS) design techniques confront to the limitation of designing the integrated circuits (ICs), especially memories, with multiple-valued logic (MVL) in nanotechnology. Gate diffusion input (GDI) technique, provides the possibility to design low power logic gates with small chip area and interconnection capacitors while the number of transistors is diminished. In this paper first ternary GDI (t-GDI) cell based on the proposed binary (two-valued) modified GDI (m-GDI) method, which is appropriate for designing circuits using MVL, is designed. Then, by using the standard ternary inverter (STI) gate implemented based on the proposed t-GDI cell with better noise margins and also small standard deviation of results, first novel design of a ternary SRAM (T-SRAM) cell is presented for nano process, which has smaller standby power dissipation and standard deviation for delay of writing and reading cycles, better read static noise margin (RSNM) and lower signal control complexity. The design of specific structure of 4-words×4-bits, ternary SRAM (4×4 T-SRAM) shows that the number of connections, chip area is decreased and power-delay product (PDP) criterion is improved for writing and reading cycles with significant small standard deviation in compare with the other similar T-SRAMs designed. The effects of different process variations such as density, number of CNTs and temperature variations are extensively evaluated by Monte-Carlo simulation, with respect to performance metrics such as delay, power dissipation and PDP of writing and reading cycles, also RSNM parameter for SRAM cells. The comparison exhibits that in all cases the proposed T-SRAM cell showing a substantial small standard deviation and considerable lower variability percentage than state-of-the art SRAM cells. So, the proposed T-SRAM cell design has the lowest sensitivity variations, thus it is an attractive choice for nano technology application in the presence of impact process and temperature variations. The simulation is done with Synopsys H-SPICE simulator in 32 nm technology under the condition of variations. [ABSTRACT FROM AUTHOR]

SRAM designing with greater storage capacity and lower power dissipation with desired stability by employing conventional CMOS technology seems to be impossible due to enhancement of short channel effect and leakage current due to increasing the number of the transistors. Up to now a lot of methods have been proposed in order to improve the performance of the logical circuits based on the CMOS technology, among of them the Gate-Diffusion Input (GDI) technique is an efficient method. In this paper the modified GDI cell (m-GDI) based on the basic GDI cell is proposed and then SRAM cell memory with 8 transistors (8T-SRAM) which uses the proposed GDI cell is presented. Due to the achieved results the stability-power dissipation ratio (SPR), the evaluation parameter in SRAM memories, is improved about 7 for 8T-SRAM which is implemented with a stack forcing method in similar carbon nanotube field-effect transistor (CNTFET) technology. Finally the 4×4 SRAM memory is proposed based on 1×1 SRAM with the help of 8T-SRAM. This memory is presented with array structures for reading and writing blocks. The simulation results reveal that the Power-Delay Product (PDP) term decreases 18% and 36% in the reading and writing cycles respectively for the stack forcing SRAM with the same array. The simulation is done with H-SPICE software in 32 nm technology under the condition of 0.9 V supply voltage, 500 MHz frequency and room temperature. [ABSTRACT FROM AUTHOR]

The novel design of asymmetric single-ended ten-transistor SRAM bit-cell (SE 10T-SRAM) using gate-all-around (GAA) carbon nanotube (CNT) FETs-based GAA CNT-GDI method along with dual-chirality technique for CNTs, the asymmetric write-assist and built-in read-assist schemes in the presence of more saving area and less energy consumption is suggested for portable/mobile multimedia applications. Based on the analytical-compact model, an equation for calculating write-static margin (WSNM) is presented by expressing the degree of dependence of the metric on the power supply voltage variation for the suggested bit-cell structure. The results of extensive simulations to evaluate the proposed bit-cell in single and multi-array structures indicate better static/dynamic noise margins, less sensitivity to process, voltage and temperature (PVT) variations, improvement of basic parameters in the presence of contact length changes, more noise-immunity with scalability at cell supply voltage, and better results in other comprehensive figure of merits (FoMs) parameter compared to nanotechnology-based counterpart circuits with the same number of transistors in the 16 nm technology node. Also, evaluating the proposed structure in the presence of changes in the contact length parameter of other transistors as a contact length sizing-level solution, indicating the achievement of an improved structure in the basic parameters such as static noise margin, power consumption, and energy-delay product (EDP) parameter compared to the default structure with a minimum-sizing contact length. Finally, in order to use the proposed bit-cell in a real application, the suggested structure for storing images based on quick response (QR) code is examined with a link between MATLAB and synopsys H-SPICE simulator tools based on suggested algorithm. The results demonstrate that the suggested bit-cell is with more appropriate and significant results in terms of comprehensive FoMs, in which the evaluations concerning the appropriate accuracy in pixel-by-pixel storage of images based on the peak signal-to-noise ratio (PSNR) and the mean structural similarity index measure (MSSIM) metrics, compared to other well-known counterpart schemes confirms the superiority of the proposed design. Hence, the proposed design can be used for various areas regarding multimedia device applications. [ABSTRACT FROM AUTHOR]

Reversible or information lossless gates have applications in nano-technology, digital signal processing (DSP), communication, computer graphics and cryptography. Gate-diffusion input (GDI) technique can provide the possibility of designing fundamental gates in ultra-low power and layout chip area with low number of transistors. A reversible logic-based single-bit magnitude comparator (RMC) circuit is presented by using the modified-GDI (m-GDI) method-based reversible gates for designing RMC in any arbitrary number of bit levels for processing at nano-scales. In this paper, several figure of merits (FOMs) like: energy consumption-propagation delay product (EDP) and worst delay-power consumption-chip area product (DPA) are evaluated and compared with other designs. The simulation results show the improvement of the evaluation parameters of the proposed RMC in compare with the other similar basic GDI-based comparators. Also, according to the simulation results, presented comparator is capable to work at extensive frequency ranges with higher maximum operating frequency (f max.). The effects of different process, voltage and the temperature (PVT) variations are extensively evaluated by Monte-Carlo simulation. According to the results, the proposed circuit is robust against PVT variations and also noise-tolerable parameter. Moreover, the proposed RMC architecture is used in images applications. The results show that output images of the proposed inexact RMC have a very high quality and resemblance to the images generated by exact RMC, thus excellent values for the peak signal-to-noise ratio (PSNR) and mean structural similarity index metric (MSSIM) indicate that the proposed inexact RMC circuit has a proper accuracy for applications such as: comparative analysis in medical images, motion detector, edge detection and segmentation in nano-technology. Therefore, using the proposed scheme can be improved in comparator circuit in chips for future generation of VLSI and ULSI blocks, like: nano-processors performance. [ABSTRACT FROM AUTHOR]

The article presents two multipliers equipped with error compensation techniques, utilizing approximate 4:2 compressors to minimize energy consumption. Compared to previous approximate multipliers with error compensation circuit, the proposed designs named, "M00" and "M01", strike a good balance between accuracy and energy consumption. Although the reduction in the number of transistors has significantly decreased the energy consumption of M00, the accuracy of this design is still more than adequate for real-world applications such as image processing and neural networks. On the other hand, M01 attains high precision while consuming less energy than other multipliers. This article compares the proposed designs with existing multipliers using HSPICE tool in 7 nm FinFET technology. Moreover, the accuracy and quality of the proposed multipliers are evaluated using MATLAB. The results reveal that both proposed designs are very efficient in image processing. According to the results, M00 has the lowest energy consumption among the considered designs. M00 is about 7% better than its counterpart in terms of the power-delay-product parameter (5% Pdynamic and 48% Pstatic). M01 presents favorable results in the sharpening, smoothing, and Discrete Cosine Transform processes. [ABSTRACT FROM AUTHOR]

The memory includes flip flap cells which can store binary information. Therefore by designing the binary storing cell, which has the low chip area and power consumption, the high capacity memories with high performance can be presented. The gate diffusion input (GDI) method employed in designing low power logic gates can decrease the chip area and parasitic and interconnection capacitors. In this paper, the modified-GDI (m-GDI) method is used based on a basic GDI method in order to design master-slave D-Flip Flap (M/S-DFF) circuit. By employing the presented M/S-DFF circuit and the Boolean functions of m-GDI method, Random Access Memory (RAM) cell is designed. For optimizing the performance of the proposed memory cell and gaining the minimum power and propagation delay, the transistors size is adjusted with non-dominated sorting genetic algorithm-II (NSGA-II) in MATLAB software. Finally, the 4-words×4-bits RAM (4×4 RAM) cell is designed and evaluated by employing optimized RAM cell with algorithm. Due to the achieved results, the power consumption of the 4×4 RAM cell is 72.3%, while its propagation delay and Power-Delay Product (PDP) criterion are decreased 75.9% and 93%, respectively, in compare with similar cells which aren't optimized. The circuit simulation is done with Synopsys H-SPICE simulator in 32 nm CNTFET technology. For ensuring the accurate function of this algorithm, it is experimented on memory cell and decoder. By comparing NSGA-II algorithm with Multiple Objective Particle Swarm Optimization (MOPSO) algorithm, it can be observed that this method has good ability in multi-objective optimization. [ABSTRACT FROM AUTHOR]

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. [ABSTRACT FROM AUTHOR]

A new 1-bit digital comparator named 14T-SR-GDI is presented with gate-diffusion-input (GDI) and single-swing-restoration (SR) techniques to attain internal gates with high driving capability. The comparator has 14 transistors which produce full-swing outputs with low power consumption. In the 14T-SR-GDI, boosted inner signals are used to activate the output gates which result in a high-speed circuit with effective scalability and the enhanced driving capability for multi-bit structures. The comparator has a low power delay product (PDP) due to the small numbers of internal nodes and capacitances and efficient power-ground-free gates. The 14T-SR-GDI comparator, fully SR-GDI-based AND, and OR gates, construct a new tree structure for multi-bit magnitude comparators including 2-bit, 4-bit, 8-bit, and 16-bit comparators. The proposed 1-bit comparator is used in image processing for difference detection, and its efficiency is proved by image quality parameters. The post-layout simulations are performed for the 1-bit to 16-bit structures under TSMC 90 nm technology. The extracted results express a PDP with an average difference of 9.59% between the regular and post-layout modes. Also, the proposed 16-bit comparator is embedded in a pad with a total area of 4331.25 μm2. The designed magnitude comparators are key components in digital signal processors (DSPs). [ABSTRACT FROM AUTHOR]

In this paper, a robust sub-threshold 13 T-SRAM cell is designed, which in addition to reducing power and energy consumption can show high reliability and have the least error at low voltages. This cell is completely free from the half-select issue, which is one of the important factors in increasing power and decreasing reliability, especially at low voltage levels for SRAM arrays. It is designed without the need of write-bit-line, which according to the proposed techniques reduces the power consumption and significantly improves the write margin, also the lack of this bit-line in the memory array can reduce the total power consumption. The used bit-line only performs for read operation, therefore it has least activity. Also, an 8 Kb memory array is proposed to be able to perform various operations with less complexity, simpler logic and lower power consumption by proposing several techniques on peripheral circuits. All obtained noise margins according to proposed techniques have the highest values among the compared cells. The average power and PDP of the cell are less than all the compared designs, so that the average power and presented FoM has been improved by 6.83% and 18.46% respectively as compared to the best value of other designs. [ABSTRACT FROM AUTHOR]

In this paper, a robust sub-threshold 13 T-SRAM cell is designed, which in addition to reducing power and energy consumption can show high reliability and have the least error at low voltages. This cell is completely free from the half-select issue, which is one of the important factors in increasing power and decreasing reliability, especially at low voltage levels for SRAM arrays. It is designed without the need of write-bit-line, which according to the proposed techniques reduces the power consumption and significantly improves the write margin, also the lack of this bit-line in the memory array can reduce the total power consumption. The used bit-line only performs for read operation, therefore it has least activity. Also, an 8 Kb memory array is proposed to be able to perform various operations with less complexity, simpler logic and lower power consumption by proposing several techniques on peripheral circuits. All obtained noise margins according to proposed techniques have the highest values among the compared cells. The average power and PDP of the cell are less than all the compared designs, so that the average power and presented FoM has been improved by 6.83% and 18.46% respectively as compared to the best value of other designs. [ABSTRACT FROM AUTHOR]

In this paper, a robust 12T-SRAM memory cell at sub-threshold voltage is designed to reduce power consumption for low power applications, that in addition to reducing power consumption can perform well at high frequencies and remain stable. For the write operation, a new method has been used that removes the write bit line and uses the supply voltage in each cell for this operation and only by applying control signals. Also, the embedded bit line is used only for read operations and reduces the activity of the bit line, and due to being floating and the way of writing, eliminates the Precharge and Write Driver circuits, so, part of the power and area consumption has been reduced. According to the techniques used, the write and read noise margin is significantly improved and the write operation become easier to perform. Also due to the existence of a separate path for the read operation, RSNM is equaled to the HSNM. The average cell power at the frequency of 100 MHz for low power applications and 0.2V supply voltage, as compared to the best previous designs, has been improved by 34.9% and the leakage power of the hold state has been reduced by 27.6% and PDP has been improved by more than 35.2%, further, the maximum operating frequency of the cell has been increased by 39.1%, while it operates with the sub-threshold voltage of 0.2V to the frequency of 2.173 GHz. [ABSTRACT FROM AUTHOR]