45-nm Radiation Hardened Cache Design

abstract: Circuits on smaller technology nodes become more vulnerable to radiation-induced upset. Since this is a major problem for electronic circuits used in space applications, designers have a variety of solutions in hand. Radiation hardening by design (RHBD) is an approach, where electronic components are designed to work properly in certain radiation environments without the use of special fabrication processes. This work focuses on the cache design for a high performance microprocessor. The design tries to mitigate radiation effects like SEE, on a commercial foundry 45 nm SOI process. The design has been ported from a previously done cache design at the 90 nm process node. The cache design is a 16 KB, 4 way set associative, write-through design that uses a no-write allocate policy. The cache has been tested to write and read at above 2 GHz at VDD = 0.9 V. Interleaved layout, parity protection, dual redundancy, and checking circuits are used in the design to achieve radiation hardness. High speed is accomplished through the use of dynamic circuits and short wiring routes wherever possible. Gated clocks and optimized wire connections are used to reduce power. Structured methodology is used to build up the entire cache.Dissertation/ThesisM.S. Electrical Engineering 201

Translation Lookaside Buffer on the 65-nm STG DICE Hardened Elements

This paper presents the design of hardened translation lookaside buffer based on Spaced Transistor Groups (STG) DICE cells in 65-nm bulk CMOS technology. The resistance to impacts of single nuclear particles is achieved by spacing transistors in two groups together with transistors of the output combinational logic. The elements contain two spaced identical groups of transistors. Charge collection from particle tracks by only transistors of just one of the two groups doesn’t lead to the cell upset. The proposed logical element of matching based on the STG DICE cell for a content-addressable memory was simulated using TCAD tool. The results show the resistance to impacts of single nuclear particles with linear energy transfer (LET) values up to 70 MeV×cm2/mg. Short-term noise pulses in combinational logic of the element can be observed in the range of LET values from 20 to 70 MeV×cm2/mg

INTEGRATED CIRCUITS FOR HIGH ENERGY PHYSICS EXPERIMETNS

Integrated Circuits are used in most people\u2019s lives in the modern societies. An important branch of research and technology is focused on Integrated Circuit (IC) design, fabrication, and their efficient applications; moreover most of these activities are about commercial productions with applications in ambient environment. However the ICs play very important role in very advance research fields, as Astronomy or High Energy Physics experiments, with absolutely extreme environments which require very interdisciplinary research orientations and innovative solutions. For example, the Fast TracKer (FTK) electronic system, which is an important part of triggering system in ATLAS experiment at European Organization for Nuclear Research (CERN), in every second of experiment selects 200 interesting events among 40 millions of total events due to collision of accelerated protons. The FTK function is based on ICs which work as Content Addressable Memory (CAM). A CAM compares the income data with stored data and gives the addresses of matching data as an output. The amount of calculation in FTK system is out of capacity of commercial ICs even in very advanced technologies, therefore the development of innovative ICs is required. The high power consumption due to huge amount of calculation was an important limitation which is overcome by an innovative architecture of CAM in this dissertation. The environment of ICs application in astrophysics and High Energy Physics experiments is different from commercial ICs environment because of high amount of radiation. This fact started to get seriously attention after the first \u201cTelstar I\u201d satellite failure because of electronic damages due to radiation effects in space, and opened a new field of research mostly about radiation hard electronics. The multidisciplinary research in radiation hard electronic field is about radiation effects on semiconductors and ICs, deep understanding about the radiation in the extreme environments, finding alternative solutions to increase the radiation tolerance of electronic components, and development of new simulation method and test techniques. Chapter 2 of this dissertation is about the radiation effects on Silicon and ICs. Moreover, In this chapter, the terminologies of radiation effects on ICs are explained. In chapter 3, the space and high energy physics experiments environments, which are two main branches of radiation hard electronics research, are studied. The radiation tolerance in on-chip circuits is achieving by two kinds of methodology: Radiation Hardening By Process (RHBP) and Radiation Hardening By Design (RHBD). RHBP is achieved by changing the conventional fabrication process of commercial ICs. RHBP is very expensive so it is out of budget for academic research, and in most cases it is exclusive for military application, with very restricted rules which make the access of non-military organizations impossible. RHBD with conventional process is the approach of radiation hard IC design in this dissertation. RHBD at hardware level can be achieved in different ways: \u2022 System level RHBD: radiation hardening at system level is achieved by algorithms which are able to extract correct data using redundant information. \u2022Architecture level RHBD: some hardware architectures are able to prevent of lost data or mitigate the radiation effects on stored data without interfacing of software. Error Correction Code (ECC) circuits and Dual Interlocked storage CEll (DICE) architecture are two examples of RHBD at architecture level. \u2022 Circuit level RHBD: at circuit level, some structures are avoided or significantly reduced. For example, feedback loops with high gain are very sensitive to radiation effects. \u2022 Layout level RHBD: there are also different solutions in layout design level to increase the radiation tolerance of circuits. Specific shapes of transistor design, optimization of the physical distance between redundant data and efficient polarization of substrate are some techniques commonly used to increase significantly the radiation tolerance of ICs. An innovative radiation hard Static Random Access Memory (SRAM), designed in three versions, is presented in chapter 4. The radiation hardening is achieved by RHBD approach simultaneously at architecture, circuit and layout levels. Complementary Metal-Oxide-Semiconductor (CMOS) 65 nm is the technology of design and the prototype chip is fabricated at Taiwan Semiconductor Manufacturing Company (TSMC). Chapter 5 is about the development of simulation models that can help to predict the radiation effect in the behavior of SRAM block. The setup system developed to characterize the radiation hard SRAM prototype chip is presented in Chapter 5. The setup system gives the possibility of testing the prototype exposed under radiation in a vacuum chamberand regular laboratory environment. Chapter 6 is about the contribution of this dissertation on FTK project and the conclusion of all research activities is shown in the final part of this dissertation. The research activities of this dissertation in supported by Italian National Institute for Nuclear Physics (INFN) as part of CHIPIX65 project and RD53 collaboration at CERN

Advanced flight computer. Special study

This report documents a special study to define a 32-bit radiation hardened, SEU tolerant flight computer architecture, and to investigate current or near-term technologies and development efforts that contribute to the Advanced Flight Computer (AFC) design and development. An AFC processing node architecture is defined. Each node may consist of a multi-chip processor as needed. The modular, building block approach uses VLSI technology and packaging methods that demonstrate a feasible AFC module in 1998 that meets that AFC goals. The defined architecture and approach demonstrate a clear low-risk, low-cost path to the 1998 production goal, with intermediate prototypes in 1996

NASA Space Engineering Research Center for VLSI System Design

This annual report outlines the activities of the past year at the NASA SERC on VLSI Design. Highlights for this year include the following: a significant breakthrough was achieved in utilizing commercial IC foundries for producing flight electronics; the first two flight qualified chips were designed, fabricated, and tested and are now being delivered into NASA flight systems; and a new technology transfer mechanism has been established to transfer VLSI advances into NASA and commercial systems

The 1991 3rd NASA Symposium on VLSI Design

Papers from the symposium are presented from the following sessions: (1) featured presentations 1; (2) very large scale integration (VLSI) circuit design; (3) VLSI architecture 1; (4) featured presentations 2; (5) neural networks; (6) VLSI architectures 2; (7) featured presentations 3; (8) verification 1; (9) analog design; (10) verification 2; (11) design innovations 1; (12) asynchronous design; and (13) design innovations 2

Towards Energy-Efficient and Reliable Computing: From Highly-Scaled CMOS Devices to Resistive Memories

The continuous increase in transistor density based on Moore\u27s Law has led us to highly scaled Complementary Metal-Oxide Semiconductor (CMOS) technologies. These transistor-based process technologies offer improved density as well as a reduction in nominal supply voltage. An analysis regarding different aspects of 45nm and 15nm technologies, such as power consumption and cell area to compare these two technologies is proposed on an IEEE 754 Single Precision Floating-Point Unit implementation. Based on the results, using the 15nm technology offers 4-times less energy and 3-fold smaller footprint. New challenges also arise, such as relative proportion of leakage power in standby mode that can be addressed by post-CMOS technologies. Spin-Transfer Torque Random Access Memory (STT-MRAM) has been explored as a post-CMOS technology for embedded and data storage applications seeking non-volatility, near-zero standby energy, and high density. Towards attaining these objectives for practical implementations, various techniques to mitigate the specific reliability challenges associated with STT-MRAM elements are surveyed, classified, and assessed herein. Cost and suitability metrics assessed include the area of nanomagmetic and CMOS components per bit, access time and complexity, Sense Margin (SM), and energy or power consumption costs versus resiliency benefits. In an attempt to further improve the Process Variation (PV) immunity of the Sense Amplifiers (SAs), a new SA has been introduced called Adaptive Sense Amplifier (ASA). ASA can benefit from low Bit Error Rate (BER) and low Energy Delay Product (EDP) by combining the properties of two of the commonly used SAs, Pre-Charge Sense Amplifier (PCSA) and Separated Pre-Charge Sense Amplifier (SPCSA). ASA can operate in either PCSA or SPCSA mode based on the requirements of the circuit such as energy efficiency or reliability. Then, ASA is utilized to propose a novel approach to actually leverage the PV in Non-Volatile Memory (NVM) arrays using Self-Organized Sub-bank (SOS) design. SOS engages the preferred SA alternative based on the intrinsic as-built behavior of the resistive sensing timing margin to reduce the latency and power consumption while maintaining acceptable access time

Analysis of Demographic Variables and Levels of Stress in Law Enforcement Officers

Employment in a law enforcement profession exposes an individual to potential stressors not experienced in most other professions. Sporadic efforts have been made to design stress management programs to assist officers in coping with the demands of their jobs. Much of the previous research on law enforcement stress has focused on examining the effectiveness of various coping skills; however, the training has focused on teaching a healthy lifestyle. This study seeks to add to the existing research by examining what elements of the job are perceived as the most stressful and what demographic variables, if any, may influence an individual\u27s perception of work-related stress

Conception de systèmes embarqués fiables et auto-réglables : applications sur les systèmes de transport ferroviaire

During the last few decades, a tremendous progress in the performance of semiconductor devices has been accomplished. In this emerging era of high performance applications, machines need not only to be efficient but also need to be dependable at circuit and system levels. Several works have been proposed to increase embedded systems efficiency by reducing the gap between software flexibility and hardware high-performance. Due to their reconfigurable aspect, Field Programmable Gate Arrays (FPGAs) represented a relevant step towards bridging this performance/flexibility gap. Nevertheless, Dynamic Reconfiguration (DR) has been continuously suffering from a bottleneck corresponding to a long reconfiguration time.In this thesis, we propose a novel medium-grained high-speed dynamic reconfiguration technique for DSP48E1-based circuits. The idea is to take advantage of the DSP48E1 slices runtime reprogrammability coupled with a re-routable interconnection block to change the overall circuit functionality in one clock cycle. In addition to the embedded systems efficiency, this thesis deals with the reliability chanllenges in new sub-micron electronic systems. In fact, as new technologies rely on reduced transistor size and lower supply voltages to improve performance, electronic circuits are becoming remarkably sensitive and increasingly susceptible to transient errors. The system-level impact of these errors can be far-reaching and Single Event Transients (SETs) have become a serious threat to embedded systems reliability, especially for especially for safety critical applications such as transportation systems. The reliability enhancement techniques that are based on overestimated soft error rates (SERs) can lead to unnecessary resource overheads as well as high power consumption. Considering error masking phenomena is a fundamental element for an accurate estimation of SERs.This thesis proposes a new cross-layer model of circuits vulnerability based on a combined modeling of Transistor Level (TLM) and System Level Masking (SLM) mechanisms. We then use this model to build a self adaptive fault tolerant architecture that evaluates the circuit’s effective vulnerability at runtime. Accordingly, the reliability enhancement strategy is adapted to protect only vulnerable parts of the system leading to a reliable circuit with optimized overheads. Experimentations performed on a radar-based obstacle detection system for railway transportation show that the proposed approach allows relevant reliability/resource utilization tradeoffs.Un énorme progrès dans les performances des semiconducteurs a été accompli ces dernières années. Avec l’´émergence d’applications complexes, les systèmes embarqués doivent être à la fois performants et fiables. Une multitude de travaux ont été proposés pour améliorer l’efficacité des systèmes embarqués en réduisant le décalage entre la flexibilité des solutions logicielles et la haute performance des solutions matérielles. En vertu de leur nature reconfigurable, les FPGAs (Field Programmable Gate Arrays) représentent un pas considérable pour réduire ce décalage performance/flexibilité. Cependant, la reconfiguration dynamique a toujours souffert d’une limitation liée à la latence de reconfiguration.Dans cette thèse, une nouvelle technique de reconfiguration dynamiqueau niveau ”grain-moyen” pour les circuits à base de blocks DSP48E1 est proposée. L’idée est de profiter de la reprogrammabilité des blocks DSP48E1 couplée avec un circuit d’interconnection reconfigurable afin de changer la fonction implémentée par le circuit en un cycle horloge. D’autre part, comme les nouvelles technologies s’appuient sur la réduction des dimensions des transistors ainsi que les tensions d’alimentation, les circuits électroniques sont devenus de plus en plus susceptibles aux fautes transitoires. L’impact de ces erreurs au niveau système peut être catastrophique et les SETs (Single Event Transients) sont devenus une menace tangible à la fiabilité des systèmes embarqués, en l’occurrence pour les applications critiques comme les systèmes de transport. Les techniques de fiabilité qui se basent sur des taux d’erreurs (SERs) surestimés peuvent conduire à un gaspillage de ressources et par conséquent un cout en consommation de puissance électrique. Il est primordial de prendre en compte le phénomène de masquage d’erreur pour une estimation précise des SERs.Cette thèse propose une nouvelle modélisation inter-couches de la vulnérabilité des circuits qui combine les mécanismes de masquage au niveau transistor (TLM) et le masquage au niveau Système (SLM). Ce modèle est ensuite utilisé afin de construire une architecture adaptative tolérante aux fautes qui évalue la vulnérabilité effective du circuit en runtime. La stratégie d’amélioration de fiabilité est adaptée pour ne protéger que les parties vulnérables du système, ce qui engendre un circuit fiable avec un cout optimisé. Les expérimentations effectuées sur un système de détection d’obstacles à base de radar pour le transport ferroviaire montre que l’approche proposée permet d’´établir un compromis fiabilité/ressources utilisées