In-Memory Computing on Resistive RAM Systems Using Majority Operation

2021 ◽  
Author(s):  
F. Lalchhandama ◽  
Mukesh Sahani ◽  
Vompolu Mohan Srinivas ◽  
Indranil Sengupta ◽  
Kamalika Datta
Keyword(s):  
Nonvolatile Memory ◽  
Memory Systems ◽  
Cmos Technology ◽  
Mapping Method ◽  
Mapping Technique ◽  
Sense Amplifiers ◽  
Logic Operations ◽  
Memristor Crossbar ◽  
Logic Functions ◽  
Nmos Transistors

Memristors can be used to build nonvolatile memory systems with in-memory computing (IMC) capabilities. A number of prior works demonstrate the design of an IMC-capable memory macro using a memristor crossbar. However, read disturbance limits the use of such memory systems built using a 0-transistor, 1-RRAM (0T1R) structure that suffers from the sneak path problem. In this paper, we introduce a scheme for both memory and logic operations using the 1-transistor, 1-RRAM (1T1R) memristor crossbar, which effectively mitigates the read disturbance problem. The memory array is designed using nMOS transistors and the VTEAM memristor model. The peripheral circuitry like decoders, voltage multiplexers, and sense amplifiers is designed using a 45[Formula: see text]nm CMOS technology node. We introduce a mapping technique to realize arbitrary logic functions using Majority (MAJ) gate operations in the 1T1R crossbar. Through extensive experimentation on benchmark functions, it has been found that the proposed mapping method gives an improvement of 65% or more in terms of the number of time steps required, and 59% or more in terms of energy consumption as compared to some of the recent methods.

scholarly journals Investigation of PVT-Aware STT-MRAM Sensing Circuits for Low-VDD Scenario

Micromachines ◽  
2021 ◽  
Vol 12 (5) ◽  
pp. 551
Author(s):  
Zhongjian Bian ◽  
Xiaofeng Hong ◽  
Yanan Guo ◽  
Lirida Naviner ◽  
Wei Ge ◽  
...  
Keyword(s):  
Nonvolatile Memory ◽  
High Speed ◽  
Low Voltage ◽  
Supply Voltage ◽  
Random Access ◽  
Magnetic Tunnel Junction ◽  
Complementary Metal Oxide Semiconductor ◽  
Current Mode ◽  
Cmos Technology ◽  
Oxide Semiconductor

Spintronic based embedded magnetic random access memory (eMRAM) is becoming a foundry validated solution for the next-generation nonvolatile memory applications. The hybrid complementary metal-oxide-semiconductor (CMOS)/magnetic tunnel junction (MTJ) integration has been selected as a proper candidate for energy harvesting, area-constraint and energy-efficiency Internet of Things (IoT) systems-on-chips. Multi-VDD (low supply voltage) techniques were adopted to minimize energy dissipation in MRAM, at the cost of reduced writing/sensing speed and margin. Meanwhile, yield can be severely affected due to variations in process parameters. In this work, we conduct a thorough analysis of MRAM sensing margin and yield. We propose a current-mode sensing amplifier (CSA) named 1D high-sensing 1D margin, high 1D speed and 1D stability (HMSS-SA) with reconfigured reference path and pre-charge transistor. Process-voltage-temperature (PVT) aware analysis is performed based on an MTJ compact model and an industrial 28 nm CMOS technology, explicitly considering low-voltage (0.7 V), low tunneling magnetoresistance (TMR) (50%) and high temperature (85 °C) scenario as the worst sensing case. A case study takes a brief look at sensing circuits, which is applied to in-memory bit-wise computing. Simulation results indicate that the proposed high-sensing margin, high speed and stability sensing-sensing amplifier (HMSS-SA) achieves remarkable performance up to 2.5 GHz sensing frequency. At 0.65 V supply voltage, it can achieve 1 GHz operation frequency with only 0.3% failure rate.

scholarly journals A 1T2C FeCAP-Based In-Situ Bitwise X(N)OR Logic Operation with Two-Step Write-Back Circuit for Accelerating Compute-In-Memory

Micromachines ◽  
2021 ◽  
Vol 12 (4) ◽  
pp. 385
Author(s):  
Qiao Wang ◽  
Donglin Zhang ◽  
Yulin Zhao ◽  
Chao Liu ◽  
Qiao Hu ◽  
...  
Keyword(s):  
Nonvolatile Memory ◽  
High Reliability ◽  
Charge Sharing ◽  
Operation Speed ◽  
Sharing Function ◽  
Logic Operations ◽  
A Charge ◽  
Process Compatibility ◽  
Ferroelectric Capacitors

Ferroelectric capacitors (FeCAPs) with high process compatibility, high reliability, ultra-low programming current and fast operation speed are promising candidates to traditional volatile and nonvolatile memory. In addition, they have great potential in the fields of storage, computing, and memory logic. Nevertheless, effective methods to realize logic and memory in FeCAP devices are still lacking. This study proposes a 1T2C FeCAP-based in situ bitwise X(N)OR logic based on a charge-sharing function. First, using the 1T2C structure and a two-step write-back circuit, the nondestructive reading is realized with less complexity than the previous work. Second, a method of two-line activation is used during the operation of X(N)OR. The verification results show that the speed, area and power consumption of the proposed 1T2C FeCAP-based bitwise logic operations are significantly improved.

scholarly journals Implementation of Unbalanced Ternary Logic Gates with the Combination of Spintronic Memristor and CMOS

Electronics ◽  
2020 ◽  
Vol 9 (4) ◽  
pp. 542 ◽  
Author(s):  
Haifeng Zhang ◽  
Zhaowei Zhang ◽  
Mingyu Gao ◽  
Li Luo ◽  
Shukai Duan ◽  
...  
Keyword(s):  
High Efficiency ◽  
Load Capacity ◽  
Complementary Metal Oxide Semiconductor ◽  
Logic Gates ◽  
Logic Circuit ◽  
Oxide Semiconductor ◽  
Ternary Logic ◽  
Logic Operations ◽  
Almost All ◽  
Logic Functions

A memristor is a nanoscale electronic element that displays a threshold property, non-volatility, and variable conductivity. Its composite circuits are promising for the implementation of intelligence computation, especially for logic operations. In this paper, a flexible logic circuit composed of a spintronic memristor and complementary metal-oxide-semiconductor (CMOS) switches is proposed for the implementation of the basic unbalanced ternary logic gates, including the NAND, NOR, AND, and OR gates. Meanwhile, due to the participation of the memristor and CMOS, the proposed circuit has advantages in terms of non-volatility and load capacity. Furthermore, the input and output of the proposed logic are both constant voltages without signal degradation. All these three merits make the proposed circuit capable of realizing the cascaded logic functions. In order to demonstrate the validity and effectiveness of the entire work, series circuit simulations were carried out. The experimental results indicated that the proposed logic circuit has the potential to realize almost all basic ternary logic gates, and even some more complicated cascaded logic functions with a compact circuit construction, high efficiency, and good robustness.

Atomic Force High Frequency Phonons Non-volatile Dynamic Random-Access Memory Compatible with Sub-7nm ULSI CMOS Technology

MRS Advances ◽  
2019 ◽  
Vol 4 (48) ◽  
pp. 2577-2584
Author(s):  
James N. Pan
Keyword(s):  
Quantum Wells ◽  
High Frequency ◽  
Nonvolatile Memory ◽  
High Speed ◽  
Random Access ◽  
Cost Effective ◽  
Cmos Technology ◽  
Access Time ◽  
Cmos Process ◽  
Atomic Force

ABSTRACTThis paper reports a novel low power, fast nonvolatile memory utilizing high frequency phonons, atomic force dual quantum wells, ferromagnetism, coupled magnetic dipoles and random accessed magnetic devices. Very high-speed memories, such as SRAM and DRAM, are mostly volatile (data are lost when power is off). Nonvolatile memories, including FLASH and MRAM, are typically not as fast has DRAM or SRAM, and the voltages for WRITE/ERASE operations are relatively high. This paper describes a silicon nonvolatile memory that is compatible with advanced sub-7nm CMOS process. It consists of only one transistor (MOSFET) – small size, and more cost effective, compared with a 6-Transistor SRAM. There is no need to refresh, as required by DRAM. The access time can be less than 1ns – close to the speed level of relaxation time - much faster than traditional FLASH memories and comparable to volatile DRAM. The operating voltages for all memory functions can be as low as high speed CMOS.

scholarly journals Mapping technique of climate fields between GCM's and ice models

2010 ◽  
Vol 3 (1) ◽  
pp. 13-41 ◽  
Author(s):  
T. J. Reerink ◽  
M. A. Kliphuis ◽  
R. S. W. van de Wal
Keyword(s):  
General Circulation ◽  
Climate Model ◽  
Circulation Model ◽  
Mapping Method ◽  
Mapping Technique ◽  
Oblique Projection ◽  
Surface Mass ◽  
Opposite Case ◽  
Average Temperature ◽  
Community System

Abstract. Here, we present a mapping method OBLIMAP, which projects and interpolates fields like surface temperature, surface mass balance, and surface height between a geographical based coordinate system of a General Circulation Model (GCM) and a rectangular based Ice Model (IM). We derive an oblique stereographic projection and its inverse, which holds for any area at the Earth's surface, and which can be combined with two different interpolation methods. The first one is suited to interpolate the projected fields of a coarse GCM grid on a fine meshed IM grid. The second one is appropriate for the opposite case. Both grids are allowed to be arbitrary and irregularly spaced. Therefore the OBLIMAP technique is suitable for any GCM-IM combination. After a first scan of the GCM grid coordinates and the specification of the IM grid, fast mapping of various fields is possible. To and fro (GCM-IM-GCM) mapping tests with the Climate Community System Model (CCSM) at T42 resolution (~313 km) and the Regional Atmospheric Climate Model (RACMO) at ~11 km and ~55 km, show average temperature differences of less than 0.1 K with small standard deviations. OBLIMAP, available at GMD, is an accurate, robust and well-documented mapping method for coupling an IM with a GCM or to map state of the art initial and forcing fields available at geographical coordinates to any local IM grid with an optimal centered oblique projection. Currently, the oblique stereographic and the oblique Lambert azimuthal equal-area projections for both the sphere and the ellipsoid are implemented in OBLIMAP.

scholarly journals 2D Ship-Like Section Slamming Pressure Numerical Analysis by Conformal Mapping

Pomorstvo ◽  
2021 ◽  
Vol 35 (2) ◽  
pp. 353-364
Author(s):  
A. Mertcan Yasa ◽  
Abdi Kükner
Keyword(s):  
Conformal Mapping ◽  
Pressure Distribution ◽  
Accurate Method ◽  
Water Entry ◽  
Mapping Method ◽  
Design Stage ◽  
Mapping Technique ◽  
Conformal Mapping Method ◽  
Pile Up ◽  
The Mathematical Model

In this paper, a method to predict slamming pressures and pressure distribution at the time of water entry for 2D sections is presented. The mathematical model is based on the Schwarz-Christoffel conformal mapping method. This conformal mapping technique has been used to calculate slamming loads during water entry. The pile-up of water during motion is also considered and an alternative pile-up coefficient is assumed against Wagner’s generalized method. A simplified and accurate method is presented, which does not include non-linear terms and jet flow in the calculated pressure distribution on monotonically increasing 2D sections like wedge shapes. Comparison with real ship sections has been done to show accuracy of the results. Finally, a simple yet powerful method is obtained to aid the initial design stage of ships.

A new mapping technique to consider intermediate stages in multistep deep drawing

2013 ◽  
Vol 228 (9) ◽  
pp. 1557-1569 ◽  
Author(s):  
Mehdi Bostan Shirin ◽  
Ahmad Assempour
Keyword(s):  
Deep Drawing ◽  
Mapping Method ◽  
Inverse Solution ◽  
Design Stage ◽  
Mapping Technique ◽  
System Of Equations ◽  
Drawing Process ◽  
Blank Sheet ◽  
One Step ◽  
Convergence Problems

The inverse solution is helpful to determine the drawability of a part and drawing parameters at the initial design stage. The usual inverse algorithms consider the drawing process that occurs in one step and therefore they are not able to analyze the processes which need more than one drawing step. Therefore, multistep inverse solution has been used for such problems. The multistep inverse solution deals with finding the initial guesses of nodal positions on intermediate stages and solving inverse equations between two consecutive steps. In this paper, a new mapping method has been developed to find the initial nodal positions on intermediate stages and the unfolding technique has been applied to find the final nodal positions on the blank sheet. The proposed method would obtain a system of equations without convergence problems. Two examples have been considered to demonstrate the capability of the proposed modeling technique. First, a two-stage drawing process of a circular cup has been analyzed and the results have been compared with the experiment results. Second, in order to apply the technique on a non-axisymmetric part, a multistage drawing of a square cup has been examined and the results have been reported.

scholarly journals Using Object-Oriented Classification for Coastal Management in the East Central Coast of Florida: A Quantitative Comparison between UAV, Satellite, and Aerial Data

Drones ◽  
2019 ◽  
Vol 3 (3) ◽  
pp. 60 ◽  
Author(s):  
Bo Yang ◽  
Timothy L. Hawthorne ◽  
Hannah Torres ◽  
Michael Feinman
Keyword(s):  
Land Cover ◽  
Satellite Imagery ◽  
Coastal Management ◽  
Rapid Development ◽  
Object Oriented ◽  
Mapping Method ◽  
Aerial Images ◽  
Quality Data ◽  
Mapping Technique ◽  
Spectral Mapping

High resolution mapping of coastal habitats is invaluable for resource inventory, change detection, and inventory of aquaculture applications. However, coastal areas, especially the interior of mangroves, are often difficult to access. An Unmanned Aerial Vehicle (UAV), equipped with a multispectral sensor, affords an opportunity to improve upon satellite imagery for coastal management because of the very high spatial resolution, multispectral capability, and opportunity to collect real-time observations. Despite the recent and rapid development of UAV mapping applications, few articles have quantitatively compared how much improvement there is of UAV multispectral mapping methods compared to more conventional remote sensing data such as satellite imagery. The objective of this paper is to quantitatively demonstrate the improvements of a multispectral UAV mapping technique for higher resolution images used for advanced mapping and assessing coastal land cover. We performed multispectral UAV mapping fieldwork trials over Indian River Lagoon along the central Atlantic coast of Florida. Ground Control Points (GCPs) were collected to generate a rigorous geo-referenced dataset of UAV imagery and support comparison to geo-referenced satellite and aerial imagery. Multi-spectral satellite imagery (Sentinel-2) was also acquired to map land cover for the same region. NDVI and object-oriented classification methods were used for comparison between UAV and satellite mapping capabilities. Compared with aerial images acquired from Florida Department of Environmental Protection, the UAV multi-spectral mapping method used in this study provided advanced information of the physical conditions of the study area, an improved land feature delineation, and a significantly better mapping product than satellite imagery with coarser resolution. The study demonstrates a replicable UAV multi-spectral mapping method useful for study sites that lack high quality data.

scholarly journals A BTT-Based Colorimetric Dual Sensor for Hg(II) and Selected Anions with Molecular Logic Operations

2016 ◽  
Vol 2016 ◽  
pp. 1-11 ◽  
Author(s):  
Veikko Uahengo ◽  
Ping Cai ◽  
Likius S. Daniel
Keyword(s):  
Charge Transfer Band ◽  
Color Changes ◽  
H Nmr ◽  
Naked Eye ◽  
Molecular Logic ◽  
Dual Sensor ◽  
One Step ◽  
Anions And Cations ◽  
Logic Operations ◽  
Logic Functions

A benzotrithiophenes (BTT) based colorimetric sensor (2) was synthesized via a simple one-step reaction process, and its recognition properties towards several biologically important anions and cations were investigated by naked eye observation and spectroscopic methods of UV-vis and 1H NMR analysis in DMSO. The molar addition of anions such as F−, AcO−, and H2PO4- induced a marked red shift of the charge transfer band (Δλ=94 nm, from 440 nm to 534 nm) concomitant with a clearly visible “naked eye” detectable colorimetric activities (from orange to pink). However, the molar addition of H2PO4- did not induce significant spectral changes, compared to F− and AcO−. Furthermore, the molar addition of Hg2+ to 2 resulted in hypochromic shift at 440 nm and the eventual disappearance of a low energy band at 534 nm, concomitant with the colorimetric activities (from orange to yellow). Moreover, both spectral and color changes induced by the addition of anions (F− and AcO−) were all reversible by the molar addition of metal cations of 3d5–10. The reversibility properties triggered the logic operation studies, and, subsequently, the complementary IMP/INH logic functions based on color and spectral switching (ON/OFF) were confirmed. Conclusively, 2 can thus be utilized as a colorimetric molecular switch modulated by AcO−/MII.

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