Low Power VLSI Circuit Design Research Articles

Concurrent Ternary Galois-based Computation using Nano-apex Multiplexing Nibs of Regular Three-dimensional Networks, Part II: Formalistic Architecture Realization

Novel realizations of concurrent computations utilizing three-dimensional lattice networks and their corresponding carbon-based field emission controlled switching is introduced in this article. The formalistic ternary nano-based implementation utilizes recent findings in field emission and nano applications which include carbon-based nanotubes and nanotips for three-valued lattice computing via field-emission methods. The presented work implements multi-valued Galois functions by utilizing concurrent nano-based lattice systems, which use two-to-one controlled switching via carbon-based field emission devices by using nano-apex carbon fibers and carbon nanotubes that were presented in the first part of the article. The introduced computational extension utilizing many-to-one carbon field-emission devices will be further utilized in implementing congestion-free architectures within the third part of the article. The emerging nano-based technologies form important directions in low-power compact-size regular lattice realizations, in which carbon-based devices switch less-costly and more-reliably using much less power than silicon-based devices. Applications include low-power design of VLSI circuits for signal processing and control of autonomous robots.

Parallel processing via carbon field emission-based controlled-switching of regular bijective nano systolic networks, Part II

Purpose The purpose of this paper is to introduce new implementations for parallel processing applications using bijective systolic networks and their corresponding carbon-based field emission controlled switching. The developed implementations are performed in the reversible domain to perform the required bijective parallel computing, where the implementations for parallel computations that utilize the presented field-emission controlled switching and their corresponding many-valued (m-ary) extensions for the use in nano systolic networks are introduced. The second part of the paper introduces the implementation of systolic computing using two-to-one controlled switching via carbon-based field emission that were presented in the first part of the paper, and the computational extension to the general case of many-valued (m-ary) systolic networks utilizing many-to-one carbon-based field emission is also introduced. Design/methodology/approach The introduced systolic systems utilize recent findings in field emission and nano applications to implement the functionality of the basic bijective systolic network. This includes many-valued systolic computing via field-emission techniques using carbon-based nanotubes and nanotips. The realization of bijective logic circuits in current and emerging technologies can be very important for various reasons. The reduction of power consumption is a major requirement for the circuit design in future technologies, and thus, the new nano systolic circuits can play an important role in the design of circuits that consume minimal power for future applications such as in low-power signal processing. In addition, the implemented bijective systems can be utilized to implement massive parallel processing and thus obtaining very high processing performance, where the implementation will also utilize the significant size reduction within the nano domain. The extensions of implementations to field emission-based many-valued systolic networks using the introduced bijective nano systolic architectures are also presented. Findings Novel bijective systolic architectures using nano-based field emission implementations are introduced in this paper, and the implementation using the general scheme of many-valued computing is presented. The carbon-based field emission implementation of nano systolic networks is also introduced. This is accomplished using the introduced field-emission carbon-based devices, where field emission from carbon nanotubes and nano-apex carbon fibers is utilized. The implementations of the many-valued bijective systolic networks utilizing the introduced nano-based architectures are also presented. Practical implications The introduced bijective systolic implementations form new important directions in the systolic realizations using the newly emerging nano-based technologies. The 2-to-1 multiplexer is a basic building block in “switch logic,” where in switch logic, a logic circuit is realized as a combination of switches rather than a combination of logic gates as in the gate logic, which proves to be less costly in synthesizing multiplexer-based wide variety of modern circuits and systems since nano implementations exist in very compact space where carbon-based devices switch reliably using much less power than silicon-based devices. The introduced implementations for nano systolic computation are new and interesting for the design in future nanotechnologies that require optimal design specifications of minimum power consumption and minimum size layout such as in low-power control of autonomous robots and in the adiabatic low-power VLSI circuit design for signal processing applications. Originality/value The introduced bijective systolic implementations form new important directions in the systolic realizations utilizing the newly emerging nanotechnologies. The introduced implementations for nano systolic computation are new and interesting for the design in future nanotechnologies that require optimal design specifications of high performance, minimum power and minimum size.

Reconfigurable CPLAG and Modified PFAL Adiabatic Logic Circuits

Previously, authors have proposed CPLAG and MCPLAG circuits extracting benefits of CPL family implemented based upon semiadiabatic logic for low power VLSI circuit design along with gating concept. Also authors have communicated RCPLAG circuits adding another dimension of reconfigurability into CPLAG/MCPLAG circuits. Moving ahead, in this paper, authors have implemented/reconfigured RCPLAG universal Nand/And gate and universal Nor/Or gate for extracting behavior of dynamic positive edge triggered DFF. Authors have also implemented Adder/Subtractor circuit using different techniques. Authors have also reported modification in PFAL semiadiabatic circuit family to further reduce the power dissipation. Functionality of these is verified and found to be satisfactory. Further these are examined rigorously with voltage, Cload, temperature, and transistor size variation. Performance of these is examined with these variations with power dissipation, delays, rise, and fall times associated. From the analysis it is found that best operating condition for DFF based upon RCPLAG universal gate can be achieved at supply voltage lower than 3 V which can be used for different transistor size up to 36 μm. Average power dissipation is 0.2 μW at 1 V and 30 μW at 2 V at 100 ff Cload 25°C approximately. Average power dissipated by CPLAG Adder/Subtractot is 58 μW. Modified PFAL circuit reduces average power by 9% approximately.

Evolution of Structure of Some Binary Group-Based N-Bit Compartor, N-To-2N Decoder by Reversible Technique

Reversible logic has attracted substantial interest due to its low power consumption which is the main concern of low power VLSI circuit design. In this paper, a novel 4x4 reversible gate called inventive gate has been introduced and using this gate 1-bit, 2-bit, 8-bit, 32-bit and n-bit group-based reversible comparator have been constructed with low value of reversible parameters. The MOS transistor realizations of 1-bit, 2- bit, and 8-bit of reversible comparator are also presented and finding power, delay and power delay product (PDP) with appropriate aspect ratio W/L. Novel inventive gate has the ability to use as an n-to-2n decoder. Different proposed novel reversible circuit design style is compared with the existing ones. The relative results shows that the novel reversible gate wide utility, group-based reversible comparator outperforms the present design style in terms of number of gates, garbage outputs and constant input.

Low Power VLSI Circuit Design with Fine-Grain Voltage Engineering

In order to cope with the increasing leakage power and the increasing device variability in VLSI’s, the required control size of both the space-domain and the time-domain is decreasing. This paper shows the several recent fine-grain voltage engineerings for the low power VLSI circuit design. The space-domain fine-grain voltage engineering includes the fine-grain power supply voltage with 3D-structured on-chip buck converters with the maximum power efficiency up to 71.3% in 0.35-µm CMOS and the fine-grain body bias control to reduce power supply voltage in 90-nm CMOS. The time-domain fine-grain voltage engineering includes accelerators for the power supply voltage hopping with a 5-ns transition time in 0.18-µm CMOS, the power supply noise canceller with the 32% power supply noise reduction in 90-nm CMOS, and backgate bias accelerators for fast wake-up with 1.5-V change of backgate voltage in 35 ns in 90-nm CMOS.

Low Power VLSI Circuit Design with Fine-Grain Voltage Engineering

Low Power VLSI Circuit Design with Fine-Grain Voltage Engineering

Low-voltage low-power CMOS full adder

Low-power design of VLSI circuits has been identified as a critical technological need in recent years due to the high demand for portable consumer electronics products. In this regard many innovative designs for basic logic functions using pass transistors and transmission gates have appeared in the literature recently. These designs relied on the intuition and cleverness of the designers, without involving formal design procedures. Hence, a formal design procedure for realising a minimal transistor CMOS pass network XOR-XNOR cell, that is fully compensated for threshold voltage drop in MOS transistors, is presented. This new cell can reliably operate within certain bounds when the power supply voltage is scaled down, as long as due consideration is given to the sizing of the MOS transistors during the initial design step. A low transistor count full adder cell using the new XOR-XNOR cell is also presented.