scholarly journals Approximate Square Root Circuits with Low Latency and Power Dissipation

Electronics ◽  
2021 ◽  
Vol 11 (1) ◽  
pp. 46
Author(s):  
Duhwan Kim ◽  
Sunggu Lee

This paper proposes a series of approximate square root circuit designs with high accuracy, low latency, low area, and low power dissipation requirements. The proposed designs are constructed using an array of controlled add–subtract cell elements with both exact and approximate versions. The utility of the proposed designs are evaluated by utilizing them in an example image contrast enhancement application with demonstrably satisfactory results and large peak signal-to-noise ratios and structural similarity values. The accuracy and hardware characteristics of the proposed square root designs are also analyzed and compared with previously proposed state-of-the-art approximate square root designs. When applied to a 16-bit radicand (the number under the square root symbol), the proposed designs have the lowest error rates, normalized mean error distances, and mean relative error distances by at least 1.8x when compared to all previous methods using the same number of approximate cells. When the designs were synthesized using Synopsys Design Compiler with a 28 nm bulk CMOS process, the delay, area, power, and power-delay-product characteristics outperform all previous designs in all but a few cases. These results demonstrate that the proposed designs permit the use of a flexible range of approximate designs with varying accuracy and hardware overhead characteristics, and a suitable design can be selected based on the user design requirements.

VLSI Design ◽  
2002 ◽  
Vol 15 (2) ◽  
pp. 547-553
Author(s):  
S. M. Rezaul Hasan ◽  
Yufridin Wahab

This paper explores the deterministic transistor reordering in low-voltage dynamic BiCMOS logic gates, for reducing the dynamic power dissipation. The constraints of load driving (discharging) capability and NPN turn-on delay for MOSFET reordered structures has been carefully considered. Simulations shows significant reduction in the dynamic power dissipation for the transistor reordered BiCMOS structures. The power-delay product figure-of-merit is found to be significantly enhanced without any associated silicon-area penalty. In order to experimentally verify the reduction in power dissipation, original and reordered structures were fabricated using the MOSIS 2 μm N-well analog CMOS process which has a P-base layer for bipolar NPN option. Measured results shows a 20% reduction in the power dissipation for the transistor reordered structure, which is in close agreement with the simulation.


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.


Electronics ◽  
2021 ◽  
Vol 10 (14) ◽  
pp. 1718
Author(s):  
Neha Gupta ◽  
Ambika Prasad Shah ◽  
Sajid Khan ◽  
Santosh Kumar Vishvakarma ◽  
Michael Waltl ◽  
...  

This paper proposes an error-tolerant reconfigurable VDD (R-VDD) scaled SRAM architecture, which significantly reduces the read and hold power using the supply voltage scaling technique. The data-dependent low-power 10T (D2LP10T) SRAM cell is used for the R-VDD scaled architecture with the improved stability and lower power consumption. The R-VDD scaled SRAM architecture is developed to avoid unessential read and hold power using VDD scaling. In this work, the cells are implemented and analyzed considering a technologically relevant 65 nm CMOS node. We analyze the failure probability during read, write, and hold mode, which shows that the proposed D2LP10T cell exhibits the lowest failure rate compared to other existing cells. Furthermore, the D2LP10T cell design offers 1.66×, 4.0×, and 1.15× higher write, read, and hold stability, respectively, as compared to the 6T cell. Moreover, leakage power, write power-delay-product (PDP), and read PDP has been reduced by 89.96%, 80.52%, and 59.80%, respectively, compared to the 6T SRAM cell at 0.4 V supply voltage. The functional improvement becomes even more apparent when the quality factor (QF) is evaluated, which is 458× higher for the proposed design than the 6T SRAM cell at 0.4 V supply voltage. A significant improvement of power dissipation, i.e., 46.07% and 74.55%, can also be observed for the R-VDD scaled architecture compared to the conventional array for the respective read and hold operation at 0.4 V supply voltage.


2015 ◽  
Vol 2015 ◽  
pp. 1-13 ◽  
Author(s):  
Alireza Monemi ◽  
Chia Yee Ooi ◽  
Muhammad Nadzir Marsono

Network-on-Chip (NoC) is fast emerging as an on-chip communication alternative for many-core System-on-Chips (SoCs). However, designing a high performance low latency NoC with low area overhead has remained a challenge. In this paper, we present a two-clock-cycle latency NoC microarchitecture. An efficient request masking technique is proposed to combine virtual channel (VC) allocation with switch allocation nonspeculatively. Our proposed NoC architecture is optimized in terms of area overhead, operating frequency, and quality-of-service (QoS). We evaluate our NoC against CONNECT, an open source low latency NoC design targeted for field-programmable gate array (FPGA). The experimental results on several FPGA devices show that our NoC router outperforms CONNECT with 50% reduction of logic cells (LCs) utilization, while it works with 100% and 35%~20% higher operating frequency compared to the one- and two-clock-cycle latency CONNECT NoC routers, respectively. Moreover, the proposed NoC router achieves 2.3 times better performance compared to CONNECT.


Author(s):  
Shivangi Chandrakar ◽  
Deepika Gupta ◽  
Manoj Kumar Majumder

The metal–semiconductor (MES)-based through silicon vias (TSV) has provided attractive solutions over conventional metal–insulator–semiconductor (MIS) TSVs in recent three-dimensional (3D) integration. This paper aims a comprehensive performance analysis of MIS and MES structures considering different TSV shapes such as cylindrical, tapered, annular, and square. At 32[Formula: see text]nm technology, a CMOS-based coupled driver-via-load (DVL) setup is introduced wherein each via is represented an equivalent RLGC model of MIS- and MES-based TSV shapes. The proposed electrical model accurately considers the impact of micro bump and inter-metal dielectric (IMD) effects at 32[Formula: see text]nm technology as per the fabrication house. A 3D electromagnetic (EM) structural wave simulation is performed to validate the RLGC model parameters of different TSV structures for an operating frequency of up to 20[Formula: see text]GHz. The proposed DVL setup is used to analyze the propagation delay, power dissipation, and dynamic crosstalk for different MIS- and MES-based TSV shapes. A significant improvement in the cross-coupling behavior can be obtained using the MES-based tapered TSV compared to the other MIS structures. Additionally, the power delay product (PDP) of the tapered MES is reduced by 92.4% compared to the conventional MIS-based cylindrical TSV.


Author(s):  
Cuauhtemoc R. Aguilera-Galicia ◽  
Omar Longoria-Gandara ◽  
Oscar A. Guzman-Ramos ◽  
Luis Pizano-Escalante ◽  
Javier Vazouez-Castillo

2014 ◽  
Vol 573 ◽  
pp. 187-193 ◽  
Author(s):  
Anitha Ponnusamy ◽  
Palaniappan Ramanathan

The recent increase in popularity of portable systems and rapid growth of packaging density in VLSI circuit’s has enable designers to design complex functional units on a single chip. Power, area and speed plays a major role in the design and optimization of an integrated circuit. Carry select adder is high speed final stage adder widely used in many data processing units. In this work, conventional D-flip flop is replaced by a new design using negative edge triggered D-flip flop. The proposed CSA is implemented in a faster partitioned Dadda multiplier and simulated by using MICROWIND tool. The results reveal that for 16 bit CSA improvement of power delay product (PDP) of the proposed design using negative edge triggered D flip flop is 78% & 18% when compared to CSA with BEC and CSA with conventional D flip flop. When CSA implemented in a partitioned Dadda multiplier it results in performance improvement of 74 % with little increase in total power dissipation.


Author(s):  
Abhijit Asthana ◽  
Shyam Akashe

D-Flip Flop (D_FF) is a very important component of various digital, analog and mixed signal systems and designs. It is obvious to come up with optimized D_FF, that cater the needs of low leakage power, less power dissipation, less chip area on the chip and low delays. This paper presents a comparative study of various logically optimized circuits of D_FF using 8T, 11T, 12T and conventional 18T D_FF. The simulation, test circuits, schematics & layouts etc are done on Cadence Virtuoso tool in 180 nm technology. Designs are compared on grounds of power dissipation, leakage power, delays and power delay product.


2013 ◽  
Vol 321-324 ◽  
pp. 361-366
Author(s):  
Yan Yu Ding ◽  
De Ming Wang ◽  
Qing Qing Huang ◽  
Hong Zhou Tan

A high performance full adder circuit with full voltage-swing based on a novel 7-transistor xor-xnor cell is proposed in this paper. In our design, we exploit a novel 7-transistor xor-xnor circuit with a signal level restorer in a feedback path to settle the threshold voltage loss problem. Then we present a new high-performance 1-bit full adder based on the designed xor-xnor cell, pass-transistors and transmission gates. The simulation results prove that, compared with other designs in literature, the proposed full adder shows its superiority for less power dissipation, lower critical path delay and smaller power-delay product, and still provides full voltage swing in all nodes of the circuit.


2010 ◽  
Vol 159 ◽  
pp. 186-191 ◽  
Author(s):  
Jian Ping Hu ◽  
Jia Guo Zhu

Scaling down sizes of MOS transistors has resulted in dramatic increase of leakage currents. The leakage dissipation caused by leakage currents is becoming an increasingly important fraction of the total power dissipation in nanometer integrated circuits. To decrease leakage power dissipations is becoming more and more important in micro-power nanometer circuits. An improved CAL register file using DTCMOS (Dual-Threshold Technique) for reducing leakage dissipations in active mode is addressed in this paper. The BSIM4 model is adopted to reflect the characteristics of the leakage currents. All circuits are simulated using HSPICE at 45nm CMOS process. Simulation results show that the register file with dual-threshold can reduce about 15.6% power dissipations.


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