22 research outputs found

    Radiation Hardened by Design Methodologies for Soft-Error Mitigated Digital Architectures

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    abstract: Digital architectures for data encryption, processing, clock synthesis, data transfer, etc. are susceptible to radiation induced soft errors due to charge collection in complementary metal oxide semiconductor (CMOS) integrated circuits (ICs). Radiation hardening by design (RHBD) techniques such as double modular redundancy (DMR) and triple modular redundancy (TMR) are used for error detection and correction respectively in such architectures. Multiple node charge collection (MNCC) causes domain crossing errors (DCE) which can render the redundancy ineffectual. This dissertation describes techniques to ensure DCE mitigation with statistical confidence for various designs. Both sequential and combinatorial logic are separated using these custom and computer aided design (CAD) methodologies. Radiation vulnerability and design overhead are studied on VLSI sub-systems including an advanced encryption standard (AES) which is DCE mitigated using module level coarse separation on a 90-nm process with 99.999% DCE mitigation. A radiation hardened microprocessor (HERMES2) is implemented in both 90-nm and 55-nm technologies with an interleaved separation methodology with 99.99% DCE mitigation while achieving 4.9% increased cell density, 28.5 % reduced routing and 5.6% reduced power dissipation over the module fences implementation. A DMR register-file (RF) is implemented in 55 nm process and used in the HERMES2 microprocessor. The RF array custom design and the decoders APR designed are explored with a focus on design cycle time. Quality of results (QOR) is studied from power, performance, area and reliability (PPAR) perspective to ascertain the improvement over other design techniques. A radiation hardened all-digital multiplying pulsed digital delay line (DDL) is designed for double data rate (DDR2/3) applications for data eye centering during high speed off-chip data transfer. The effect of noise, radiation particle strikes and statistical variation on the designed DDL are studied in detail. The design achieves the best in class 22.4 ps peak-to-peak jitter, 100-850 MHz range at 14 pJ/cycle energy consumption. Vulnerability of the non-hardened design is characterized and portions of the redundant DDL are separated in custom and auto-place and route (APR). Thus, a range of designs for mission critical applications are implemented using methodologies proposed in this work and their potential PPAR benefits explored in detail.Dissertation/ThesisDoctoral Dissertation Electrical Engineering 201

    The 1992 4th NASA SERC Symposium on VLSI Design

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    Papers from the fourth annual NASA Symposium on VLSI Design, co-sponsored by the IEEE, are presented. Each year this symposium is organized by the NASA Space Engineering Research Center (SERC) at the University of Idaho and is held in conjunction with a quarterly meeting of the NASA Data System Technology Working Group (DSTWG). One task of the DSTWG is to develop new electronic technologies that will meet next generation electronic data system needs. The symposium provides insights into developments in VLSI and digital systems which can be used to increase data systems performance. The NASA SERC is proud to offer, at its fourth symposium on VLSI design, presentations by an outstanding set of individuals from national laboratories, the electronics industry, and universities. These speakers share insights into next generation advances that will serve as a basis for future VLSI design

    Amostrador CMOS para receptor de radiofrequência baseado em subamostragem com dupla quadratura

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    Orientador : Prof. PhD. André Augusto MarianoCoorientador : Prof. PhD. Bernardo LeiteDissertação (mestrado) - Universidade Federal do Paraná, Setor de Tecnologia, Programa de Pós-Graduação em Engenharia Elétrica. Defesa: Curitiba, 25/08/2017Inclui referências : f. 94-97Resumo: Desde do in.cio da década de 80, a sociedade tem experimentado transformações no modo de se comunicar. Essas mudanças, todavia, são resultados de inova..es tecnológicas que, por sua vez, são sustentadas por grandes investimentos do setor de telecomunicação em pesquisas tecnológicas. Neste sentido, (LOLIS, 2011) propõe um receptor de radiofrequência baseado em subamostragem para demodular sinal diretamente em banda passante e que utiliza deslocamentos unilaterais de frequência para evitar a interferência com o sinal-imagem. O objetivo deste trabalho e, portanto, projetar um circuito amostra dor que atenda aos requisitos funcionais do receptor de radiofrequência baseado em subamostragem com dupla quadratura. Alem disso, o circuito amostra dor projetado deve mesclar duas grandezas muitas vezes antagônicas: velocidade e exatidão. Para tanto, o trabalho e dividido em introdução, receptor de radiofrequência baseado em subamostragem com dupla quadratura, introdução aos circuitos amostradores, projeto do amostrador para receptor de RF baseado em subamostragem com dupla quadratura e considerações finais. O projeto do amostrador, ainda, e dividido em blocos funcionais, dimensionando e analisando os pares diferenciais, os circuitos amostradores, os contadores e circuitos de sincronismo. Em relação a velocidade e precisão, a estratégia de polarização que permite a saída DC do par diferencial da entrada polarizar o par diferencial da saída leva a remoção do capacitor de retenção. A remoção do capacitor incrementa a velocidade do circuito amostrador, porem degrada a exatidão do circuito. Para compensar a inexatidão, o circuito amostrador e projetado com o mínimo de largura de transistor. Deste modo, e obtido um circuito rápido e, ao mesmo tempo, exato. Palavras-chave: Amostrador, Receptor de radiofrequência, Subamostragem.Abstract: Since the beginning of the 80s, people have gone through transformations in the way they communicate. These changes, however, are the result of technological innovations which, in turn, are sustained by large investments of the telecommunication sector in technological research. On that subject, (LOLIS, 2011) proposes a radio frequency subsampling receiver to demodulate signal directly in bandpass and that uses unilateral frequency downconversion to avoid image interferers. The objective of this work is, therefore, to design a sample and hold circuit that meets the functional requirements of radiofrequency subsampling receiver with double-quadrature. In addition, the designed sample and hold circuit must blend two often antagonistic quantities: speed and accuracy. For this, the work is divided into introduction, radiofrequency subsampling receiver with double-quadrature, introduction to sample and hold circuits, sample and hold circuit design for RF subsampling receiver with double-quadrature and final considerations. The design of the sample and hold circuit is, furthermore, divided into functional blocks, scaling and analyzing the differential pairs, core of sample and hold circuits, counters and synchronism circuits. In relation to speed and accuracy, the voltage biasing strategy that allows the DC output of the input differential pair to bias the output differential par leads to the elimination of the hold capacitor. Elimination of the capacitor increases the speed of the sample and hold circuit, but degrades the accuracy of the circuit. In order to compensate for the inaccuracy, the sample and hold circuit is designed with the minimum transistor width. In this way, a fast and, at the same time, accurate circuit is obtained. Key-words: Sample and hold circuit; Radiofrequency receiver; Subsampling

    Doctor of Philosophy

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    dissertationAsynchronous design has a very promising potential even though it has largely received a cold reception from industry. Part of this reluctance has been due to the necessity of custom design languages and computer aided design (CAD) flows to design, optimize, and validate asynchronous modules and systems. Next generation asynchronous flows should support modern programming languages (e.g., Verilog) and application specific integrated circuits (ASIC) CAD tools. They also have to support multifrequency designs with mixed synchronous (clocked) and asynchronous (unclocked) designs. This work presents a novel relative timing (RT) based methodology for generating multifrequency designs using synchronous CAD tools and flows. Synchronous CAD tools must be constrained for them to work with asynchronous circuits. Identification of these constraints and characterization flow to automatically derive the constraints is presented. The effect of the constraints on the designs and the way they are handled by the synchronous CAD tools are analyzed and reported in this work. The automation of the generation of asynchronous design templates and also the constraint generation is an important problem. Algorithms for automation of reset addition to asynchronous circuits and power and/or performance optimizations applied to the circuits using logical effort are explored thus filling an important hole in the automation flow. Constraints representing cyclic asynchronous circuits as directed acyclic graphs (DAGs) to the CAD tools is necessary for applying synchronous CAD optimizations like sizing, path delay optimizations and also using static timing analysis (STA) on these circuits. A thorough investigation for the requirements of cycle cutting while preserving timing paths is presented with an algorithm to automate the process of generating them. A large set of designs for 4 phase handshake protocol circuit implementations with early and late data validity are characterized for area, power and performance. Benchmark circuits with automated scripts to generate various configurations for better understanding of the designs are proposed and analyzed. Extension to the methodology like addition of scan insertion using automatic test pattern generation (ATPG) tools to add testability of datapath in bundled data asynchronous circuit implementations and timing closure approaches are also described. Energy, area, and performance of purely asynchronous circuits and circuits with mixed synchronous and asynchronous blocks are explored. Results indicate the benefits that can be derived by generating circuits with asynchronous components using this methodology

    Network-on-Chip

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    Limitations of bus-based interconnections related to scalability, latency, bandwidth, and power consumption for supporting the related huge number of on-chip resources result in a communication bottleneck. These challenges can be efficiently addressed with the implementation of a network-on-chip (NoC) system. This book gives a detailed analysis of various on-chip communication architectures and covers different areas of NoCs such as potentials, architecture, technical challenges, optimization, design explorations, and research directions. In addition, it discusses current and future trends that could make an impactful and meaningful contribution to the research and design of on-chip communications and NoC systems

    Développement de circuits logiques programmables résistants aux alas logiques en technologie CMOS submicrométrique

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    The electronics associated to the particle detectors of the Large Hadron Collider (LHC), under construction at CERN, will operate in a very harsh radiation environment. Most of the microelectronics components developed for the first generation of LHC experiments have been designed with very precise experiment-specific goals and are hardly adaptable to other applications. Commercial Off-The-Shelf (COTS) components cannot be used in the vicinity of particle collision due to their poor radiation tolerance. This thesis is a contribution to the effort to cover the need for radiation-tolerant SEU-robust programmable components for application in High Energy Physics (HEP) experiments. Two components are under development: a Programmable Logic Device (PLD) and a Field-Programmable Gate Array (FPGA). The PLD is a fuse-based, 10-input, 8-I/O general architecture device in 0.25 micron CMOS technology. The FPGA under development is instead a 32x32 logic block array, equivalent to ~25k gates, in 0.13 micron CMOS. This work focussed also on the research for an SEU-robust register in both the mentioned technologies. The SEU-robust register is employed as a user data flip-flop in the FPGA and PLD designs and as a configuration cell as well in the FPGA design

    Algorithms and Circuits for Analog-Digital Hybrid Multibeam Arrays

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    Fifth generation (5G) and beyond wireless communication systems will rely heavily on larger antenna arrays combined with beamforming to mitigate the high free-space path-loss that prevails in millimeter-wave (mmW) and above frequencies. Sharp beams that can support wide bandwidths are desired both at the transmitter and the receiver to leverage the glut of bandwidth available at these frequency bands. Further, multiple simultaneous sharp beams are imperative for such systems to exploit mmW/sub-THz wireless channels using multiple reflected paths simultaneously. Therefore, multibeam antenna arrays that can support wider bandwidths are a key enabler for 5G and beyond systems. In general, N-beam systems using N-element antenna arrays will involve circuit complexities of the order of N2. This dissertation investigates new analog, digital and hybrid low complexity multibeam beamforming algorithms and circuits for reducing the associated high size, weight, and power (SWaP) complexities in larger multibeam arrays. The research efforts on the digital beamforming aspect propose the use of a new class of discrete Fourier transform (DFT) approximations for multibeam generation to eliminate the need for digital multipliers in the beamforming circuitry. For this, 8-, 16- and 32-beam multiplierless multibeam algorithms have been proposed for uniform linear array applications. A 2.4 GHz 16-element array receiver setup and a 5.8 GHz 32-element array receiver system which use field programmable gate arrays (FPGAs) as digital backend have been built for real-time experimental verification of the digital multiplierless algorithms. The multiplierless algorithms have been experimentally verified by digitally measuring beams. It has been shown that the measured beams from the multiplierless algorithms are in good agreement with the exact counterpart algorithms. Analog realizations of the proposed approximate DFT transforms have also been investigated leading to low-complex, high bandwidth circuits in CMOS. Further, a novel approach for reducing the circuit complexity of analog true-time delay (TTD) N-beam beamforming networks using N-element arrays has been proposed for wideband squint-free operation. A sparse factorization of the N-beam delay Vandermonde beamforming matrix is used to reduce the total amount of TTD elements that are needed for obtaining N number of beams in a wideband array. The method has been verified using measured responses of CMOS all-pass filters (APFs). The wideband squint-free multibeam algorithm is also used to propose a new low-complexity hybrid beamforming architecture targeting future 5G mmW systems. Apart from that, the dissertation also explores multibeam beamforming architectures for uniform circular arrays (UCAs). An algorithm having N log N circuit complexity for simultaneous generation of N-beams in an N-element UCA is explored and verified
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