3,256 research outputs found
Low Power Processor Architectures and Contemporary Techniques for Power Optimization â A Review
The technological evolution has increased the number of transistors for a given die area significantly and increased the switching speed from few MHz to GHz range. Such inversely proportional decline in size and boost in performance consequently demands shrinking of supply voltage and effective power dissipation in chips with millions of transistors. This has triggered substantial amount of research in power reduction techniques into almost every aspect of the chip and particularly the processor cores contained in the chip. This paper presents an overview of techniques for achieving the power efficiency mainly at the processor core level but also visits related domains such as buses and memories. There are various processor parameters and features such as supply voltage, clock frequency, cache and pipelining which can be optimized to reduce the power consumption of the processor. This paper discusses various ways in which these parameters can be optimized. Also, emerging power efficient processor architectures are overviewed and research activities are discussed which should help reader identify how these factors in a processor contribute to power consumption. Some of these concepts have been already established whereas others are still active research areas. © 2009 ACADEMY PUBLISHER
Design Optimization of Double Gate Based Full Adder
Full adder is the essential block of circuit of arithmeticâs found in microprocessor and microcontroller in ALU (arithmetic and logic unit). Improving the performance of the adder is very important for up gradation the performance of digital circuit of electronics in which adder is utilized. The main aim of designing of arithmetic circuit is the power consumption. In an arithmetic circuit, the adder is a critical module for operation of addition and also the core for many operations related to arithmetic. Therefore it is obliged to decrease the consumption of power of adder circuit so as to diminish the consumption of the module related to arithmetic. In this paper, a review of double gate based full adder is presented. Various works on this research work which is already available is presented and also problem related to them are presented. Keywords: DG-MOSFET, ALU, XOR, Full Adder,PTI, GDI, Diffused Gdi,Finfet, ELK, Power Grating , Stacking
Nanowire Volatile RAM as an Alternative to SRAM
Maintaining benefits of CMOS technology scaling is becoming challenging due
to increased manufacturing complexities and unwanted passive power
dissipations. This is particularly challenging in SRAM, where manufacturing
precision and leakage power control are critical issues. To alleviate some of
these challenges a novel non-volatile memory alternative to SRAM was proposed
called nanowire volatile RAM (NWRAM). Due to NWRAMs regular grid based layout
and innovative circuit style, manufacturing complexity is reduced and at the
same time considerable benefits are attained in terms of performance and
leakage power reduction. In this paper, we elaborate more on NWRAM circuit
aspects and manufacturability, and quantify benefits at 16nm technology node
through simulation against state-of-the-art 6T-SRAM and gridded 8T-SRAM
designs. Our results show the 10T-NWRAM to be 2x faster and 35x better in terms
of leakage when compared to high performance gridded 8T-SRAM design
A low-power, high-performance speech recognition accelerator
© 2019 IEEE. Personal use of this material is permitted. Permission from IEEE must be obtained for all other uses, in any current or future media, including reprinting/republishing this material for advertising or promotional purposes,creating new collective works, for resale or redistribution to servers or lists, or reuse of any copyrighted component of this work in other works.Automatic Speech Recognition (ASR) is becoming increasingly ubiquitous, especially in the mobile segment. Fast and accurate ASR comes at high energy cost, not being affordable for the tiny power-budgeted mobile devices. Hardware acceleration reduces energy-consumption of ASR systems, while delivering high-performance. In this paper, we present an accelerator for largevocabulary, speaker-independent, continuous speech-recognition. It focuses on the Viterbi search algorithm representing the main bottleneck in an ASR system. The proposed design consists of innovative techniques to improve the memory subsystem, since memory is the main bottleneck for performance and power in these accelerators' design. It includes a prefetching scheme tailored to the needs of ASR systems that hides main memory latency for a large fraction of the memory accesses, negligibly impacting area. Additionally, we introduce a novel bandwidth-saving technique that removes off-chip memory accesses by 20 percent. Finally, we present a power saving technique that significantly reduces the leakage power of the accelerators scratchpad memories, providing between 8.5 and 29.2 percent reduction in entire power dissipation. Overall, the proposed design outperforms implementations running on the CPU by orders of magnitude, and achieves speedups between 1.7x and 5.9x for different speech decoders over a highly optimized CUDA implementation running on Geforce-GTX-980 GPU, while reducing the energy by 123-454x.Peer ReviewedPostprint (author's final draft
Addressing On-Chip Power Conversion and Dissipation Issues in Many-Core System-on-a-Chip based on Conventional Silicon and Emerging Nanotechnologies
Title from PDF of title page viewed August 27, 2018Dissertation advisor: Masud H ChowdhuryVitaIncludes bibliographical references (pages 158-163)Thesis (Ph.D.)--School of Computing and Engineering and Department of Physics and Astronomy. University of Missouri--Kansas City, 2017Integrated circuits (ICs) are moving towards system-on-a-chip (SOC) designs. SOC
allows various small and large electronic systems to be implemented in a single chip. This
approach enables the miniaturization of design blocks that leads to high density transistor
integration, faster response time, and lower fabrication costs. To reap the benefits of SOC
and uphold the miniaturization of transistors, innovative power delivery and power
dissipation management schemes are paramount. This dissertation focuses on on-chip
integration of power delivery systems and managing power dissipation to increase the
lifetime of energy storage elements. We explore this problem from two different angels:
On-chip voltage regulators and power gating techniques. On-chip voltage regulators reduce
parasitic effects, and allow faster and efficient power delivery for microprocessors. Power
gating techniques, on the other hand, reduce the power loss incurred by circuit blocks
during standby mode.
Power dissipation (Ptotal = Pstatic and Pdynamic) in a complementary metal-oxide
semiconductor (CMOS) circuit comes from two sources: static and dynamic. A quadratic
dependency on the dynamic switching power and a more than linear dependency on static
power as a form of gate leakage (subthreshold current) exist. To reduce dynamic power
loss, the supply power should be reduced. A significant reduction in power dissipation
occurs when portions of a microprocessor operate at a lower voltage level. This reduction
in supply voltage is achieved via voltage regulators or converters. Voltage regulators are
used to provide a stable power supply to the microprocessor. The conventional off-chip
switching voltage regulator contains a passive floating inductor, which is difficult to be
implemented inside the chip due to excessive power dissipation and parasitic effects.
Additionally, the inductor takes a very large chip area while hampering the scaling process.
These limitations make passive inductor based on-chip regulator design very unattractive
for SOC integration and multi-/many-core environments. To circumvent the challenges,
three alternative techniques based on active circuit elements to replace the passive LC filter
of the buck convertor are developed. The first inductorless on-chip switching voltage
regulator architecture is based on a cascaded 2nd order multiple feedback (MFB) low-pass
filter (LPF). This design has the ability to modulate to multiple voltage settings via pulse
with modulation (PWM). The second approach is a supplementary design utilizing a hybrid
low drop-out scheme to lower the output ripple of the switching regulator over a wider
frequency range. The third design approach allows the integration of an entire power
management system within a single chipset by combining a highly efficient switching
regulator with an intermittently efficient linear regulator (area efficient), for robust and
highly efficient on-chip regulation.
The static power (Pstatic) or subthreshold leakage power (Pleak) increases with
technology scaling. To mitigate static power dissipation, power gating techniques are
implemented. Power gating is one of the popular methods to manage leakage power during
standby periods in low-power high-speed IC design. It works by using transistor based
switches to shut down part of the circuit block and put them in the idle mode. The efficiency
of a power gating scheme involves minimum Ioff and high Ion for the sleep transistor. A
conventional sleep transistor circuit design requires an additional header, footer, or both
switches to turn off the logic block. This additional transistor causes signal delay and
increases the chip area. We propose two innovative designs for next generation sleep
transistor designs. For an above threshold operation, we present a sleep transistor design
based on fully depleted silicon-on-insulator (FDSOI) device. For a subthreshold circuit
operation, we implement a sleep transistor utilizing the newly developed silicon-on
ferroelectric-insulator field effect transistor (SOFFET). In both of the designs, the ability
to control the threshold voltage via bias voltage at the back gate makes both devices more
flexible for sleep transistors design than a bulk MOSFET. The proposed approaches
simplify the design complexity, reduce the chip area, eliminate the voltage drop by sleep
transistor, and improve power dissipation. In addition, the design provides a dynamically
controlled Vt for times when the circuit needs to be in a sleep or switching mode.Introduction -- Background and literature review -- Fully integrated on-chip switching voltage regulator -- Hybrid LDO voltage regulator based on cascaded second order multiple feedback loop -- Single and dual output two-stage on-chip power management system -- Sleep transistor design using double-gate FDSOI -- Subthreshold region sleep transistor design -- Conclusio
Design and Analysis of Low Power Dual Edge Triggered Mechanism Flip-Flop Employing Power Gating Methodology
The advancement of battery operated designs has abundantly increases the memory elements and registers to be operated in ultra-low power. That is the this paper we have proposed a design of CT_C DET flip-flop with power gating technique which is the most efficient power consuming reduction technique. The design of the power gating technique involves the pull-up transistor in the Vdd of the circuit and pull-down transistor in the ground terminal. This power gating technique reduces the power consumption by more than 40% than that of the existing design
A hardware mechanism to reduce the energy consumption of the register file of in-order architectures
This paper introduces an efficient hardware approach to reduce the register file energy consumption by turning unused registers into a low power state. Bypassing the register fields of the fetch instruction to the decode stage allows the identification of registers required by the current instruction (instruction predecode) and allows the control logic to turn them back on. They are put into the low-power state after the instruction use. This technique achieves an 85% energy reduction with no performance penalty
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