500 research outputs found

    Gestión de jerarquías de memoria híbridas a nivel de sistema

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    Tesis inédita de la Universidad Complutense de Madrid, Facultad de Informática, Departamento de Arquitectura de Computadoras y Automática y de Ku Leuven, Arenberg Doctoral School, Faculty of Engineering Science, leída el 11/05/2017.In electronics and computer science, the term ‘memory’ generally refers to devices that are used to store information that we use in various appliances ranging from our PCs to all hand-held devices, smart appliances etc. Primary/main memory is used for storage systems that function at a high speed (i.e. RAM). The primary memory is often associated with addressable semiconductor memory, i.e. integrated circuits consisting of silicon-based transistors, used for example as primary memory but also other purposes in computers and other digital electronic devices. The secondary/auxiliary memory, in comparison provides program and data storage that is slower to access but offers larger capacity. Examples include external hard drives, portable flash drives, CDs, and DVDs. These devices and media must be either plugged in or inserted into a computer in order to be accessed by the system. Since secondary storage technology is not always connected to the computer, it is commonly used for backing up data. The term storage is often used to describe secondary memory. Secondary memory stores a large amount of data at lesser cost per byte than primary memory; this makes secondary storage about two orders of magnitude less expensive than primary storage. There are two main types of semiconductor memory: volatile and nonvolatile. Examples of non-volatile memory are ‘Flash’ memory (sometimes used as secondary, sometimes primary computer memory) and ROM/PROM/EPROM/EEPROM memory (used for firmware such as boot programs). Examples of volatile memory are primary memory (typically dynamic RAM, DRAM), and fast CPU cache memory (typically static RAM, SRAM, which is fast but energy-consuming and offer lower memory capacity per are a unit than DRAM). Non-volatile memory technologies in Si-based electronics date back to the 1990s. Flash memory is widely used in consumer electronic products such as cellphones and music players and NAND Flash-based solid-state disks (SSDs) are increasingly displacing hard disk drives as the primary storage device in laptops, desktops, and even data centers. The integration limit of Flash memories is approaching, and many new types of memory to replace conventional Flash memories have been proposed. The rapid increase of leakage currents in Silicon CMOS transistors with scaling poses a big challenge for the integration of SRAM memories. There is also the case of susceptibility to read/write failure with low power schemes. As a result of this, over the past decade, there has been an extensive pooling of time, resources and effort towards developing emerging memory technologies like Resistive RAM (ReRAM/RRAM), STT-MRAM, Domain Wall Memory and Phase Change Memory(PRAM). Emerging non-volatile memory technologies promise new memories to store more data at less cost than the expensive-to build silicon chips used by popular consumer gadgets including digital cameras, cell phones and portable music players. These new memory technologies combine the speed of static random-access memory (SRAM), the density of dynamic random-access memory (DRAM), and the non-volatility of Flash memory and so become very attractive as another possibility for future memory hierarchies. The research and information on these Non-Volatile Memory (NVM) technologies has matured over the last decade. These NVMs are now being explored thoroughly nowadays as viable replacements for conventional SRAM based memories even for the higher levels of the memory hierarchy. Many other new classes of emerging memory technologies such as transparent and plastic, three-dimensional(3-D), and quantum dot memory technologies have also gained tremendous popularity in recent years...En el campo de la informática, el término ‘memoria’ se refiere generalmente a dispositivos que son usados para almacenar información que posteriormente será usada en diversos dispositivos, desde computadoras personales (PC), móviles, dispositivos inteligentes, etc. La memoria principal del sistema se utiliza para almacenar los datos e instrucciones de los procesos que se encuentre en ejecución, por lo que se requiere que funcionen a alta velocidad (por ejemplo, DRAM). La memoria principal está implementada habitualmente mediante memorias semiconductoras direccionables, siendo DRAM y SRAM los principales exponentes. Por otro lado, la memoria auxiliar o secundaria proporciona almacenaje(para ficheros, por ejemplo); es más lenta pero ofrece una mayor capacidad. Ejemplos típicos de memoria secundaria son discos duros, memorias flash portables, CDs y DVDs. Debido a que estos dispositivos no necesitan estar conectados a la computadora de forma permanente, son muy utilizados para almacenar copias de seguridad. La memoria secundaria almacena una gran cantidad de datos aun coste menor por bit que la memoria principal, siendo habitualmente dos órdenes de magnitud más barata que la memoria primaria. Existen dos tipos de memorias de tipo semiconductor: volátiles y no volátiles. Ejemplos de memorias no volátiles son las memorias Flash (algunas veces usadas como memoria secundaria y otras veces como memoria principal) y memorias ROM/PROM/EPROM/EEPROM (usadas para firmware como programas de arranque). Ejemplos de memoria volátil son las memorias DRAM (RAM dinámica), actualmente la opción predominante a la hora de implementar la memoria principal, y las memorias SRAM (RAM estática) más rápida y costosa, utilizada para los diferentes niveles de cache. Las tecnologías de memorias no volátiles basadas en electrónica de silicio se remontan a la década de1990. Una variante de memoria de almacenaje por carga denominada como memoria Flash es mundialmente usada en productos electrónicos de consumo como telefonía móvil y reproductores de música mientras NAND Flash solid state disks(SSDs) están progresivamente desplazando a los dispositivos de disco duro como principal unidad de almacenamiento en computadoras portátiles, de escritorio e incluso en centros de datos. En la actualidad, hay varios factores que amenazan la actual predominancia de memorias semiconductoras basadas en cargas (capacitivas). Por un lado, se está alcanzando el límite de integración de las memorias Flash, lo que compromete su escalado en el medio plazo. Por otra parte, el fuerte incremento de las corrientes de fuga de los transistores de silicio CMOS actuales, supone un enorme desafío para la integración de memorias SRAM. Asimismo, estas memorias son cada vez más susceptibles a fallos de lectura/escritura en diseños de bajo consumo. Como resultado de estos problemas, que se agravan con cada nueva generación tecnológica, en los últimos años se han intensificado los esfuerzos para desarrollar nuevas tecnologías que reemplacen o al menos complementen a las actuales. Los transistores de efecto campo eléctrico ferroso (FeFET en sus siglas en inglés) se consideran una de las alternativas más prometedores para sustituir tanto a Flash (por su mayor densidad) como a DRAM (por su mayor velocidad), pero aún está en una fase muy inicial de su desarrollo. Hay otras tecnologías algo más maduras, en el ámbito de las memorias RAM resistivas, entre las que cabe destacar ReRAM (o RRAM), STT-RAM, Domain Wall Memory y Phase Change Memory (PRAM)...Depto. de Arquitectura de Computadores y AutomáticaFac. de InformáticaTRUEunpu

    Always-On 674uW @ 4GOP/s Error Resilient Binary Neural Networks with Aggressive SRAM Voltage Scaling on a 22nm IoT End-Node

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    Binary Neural Networks (BNNs) have been shown to be robust to random bit-level noise, making aggressive voltage scaling attractive as a power-saving technique for both logic and SRAMs. In this work, we introduce the first fully programmable IoT end-node system-on-chip (SoC) capable of executing software-defined, hardware-accelerated BNNs at ultra-low voltage. Our SoC exploits a hybrid memory scheme where error-vulnerable SRAMs are complemented by reliable standard-cell memories to safely store critical data under aggressive voltage scaling. On a prototype in 22nm FDX technology, we demonstrate that both the logic and SRAM voltage can be dropped to 0.5Vwithout any accuracy penalty on a BNN trained for the CIFAR-10 dataset, improving energy efficiency by 2.2X w.r.t. nominal conditions. Furthermore, we show that the supply voltage can be dropped to 0.42V (50% of nominal) while keeping more than99% of the nominal accuracy (with a bit error rate ~1/1000). In this operating point, our prototype performs 4Gop/s (15.4Inference/s on the CIFAR-10 dataset) by computing up to 13binary ops per pJ, achieving 22.8 Inference/s/mW while keeping within a peak power envelope of 674uW - low enough to enable always-on operation in ultra-low power smart cameras, long-lifetime environmental sensors, and insect-sized pico-drones.Comment: Submitted to ISICAS2020 journal special issu

    Selection of a new hardware and software platform for railway interlocking

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    The interlocking system is one of the main actors for safe railway transportation. In most cases, the whole system is supplied by a single vendor. The recent regulations from the European Union direct for an “open” architecture to invite new game changers and reduce life-cycle costs. The objective of the thesis is to propose an alternative platform that could replace a legacy interlocking system. In the thesis, various commercial off-the-shelf hardware and software products are studied which could be assembled to compose an alternative interlocking platform. The platform must be open enough to adapt to any changes in the constituent elements and abide by the proposed baselines of new standardization initiatives, such as ERTMS, EULYNX, and RCA. In this thesis, a comparative study is performed between these products based on hardware capacity, architecture, communication protocols, programming tools, security, railway certifications, life-cycle issues, etc

    BotSpine - A Generic Simple Development Platform of Smartphones and Sensors or Robotics

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    The Internet of Things (IoT) emergence leads to an “intelligence” technology revolution in industrial, social, environmental and almost every aspect of life and objectives. Sensor and actuators are heavily employed in industrial production and, under the trend of IoT, smart sensors are in great demand. Smartphones stand out from other computing terminals as a result of their incomparable popularity, mobility and computer comparable computing capability. However, current IoT designs are developed among diverse platforms and systems and are usually specific to applications and patterns. There is no a standardized developing interface between smartphones and sensors/electronics that is facile and rapid for either developers or consumers to connect and control through smartphones. The goal of this thesis is to develop a simple and generic platform interconnecting smartphones and sensors and/or robotics, allowing users to develop, monitor and control all types of sensors, robotics or customer electronics simply over their smartphones through the developed platform. The research is in cooperation with a local company, Environmental Instruments Canada Inc. From the perspective of research and industrial interests, the proposed platform is designed for generally applicable, low cost, low energy, easily programmed, and smartphone based sensor and/or robotic development purposes. I will build a platform interfacing smartphones and sensors including hardware, firmware structures and software application. The platform is named BotSpine and it provides an energy-efficient real-time wireless communication. This thesis also implements BotSpine by redesigning a radon sniffer robot with the developed interface, demonstrated that BotSpine is able to achieve expectations. BotSpine performs a fast and secure connection with smartphones and its command/BASIC program features render controlling and developing robotics and electronics easy and simple

    Low power processor architecture and multicore approach for embedded systems

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    13301甲第4319号博士(工学)金沢大学博士論文本文Full 以下に掲載:1.IEICE Transactions Vol. E98-C(7) pp.544-549 2015. IEICE. 共著者: S. Otani, H. Kondo. /2.Reuse 許可エビデンス送

    Flexi-WVSNP-DASH: A Wireless Video Sensor Network Platform for the Internet of Things

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    abstract: Video capture, storage, and distribution in wireless video sensor networks (WVSNs) critically depends on the resources of the nodes forming the sensor networks. In the era of big data, Internet of Things (IoT), and distributed demand and solutions, there is a need for multi-dimensional data to be part of the Sensor Network data that is easily accessible and consumable by humanity as well as machinery. Images and video are expected to become as ubiquitous as is the scalar data in traditional sensor networks. The inception of video-streaming over the Internet, heralded a relentless research for effective ways of distributing video in a scalable and cost effective way. There has been novel implementation attempts across several network layers. Due to the inherent complications of backward compatibility and need for standardization across network layers, there has been a refocused attention to address most of the video distribution over the application layer. As a result, a few video streaming solutions over the Hypertext Transfer Protocol (HTTP) have been proposed. Most notable are Apple’s HTTP Live Streaming (HLS) and the Motion Picture Experts Groups Dynamic Adaptive Streaming over HTTP (MPEG-DASH). These frameworks, do not address the typical and future WVSN use cases. A highly flexible Wireless Video Sensor Network Platform and compatible DASH (WVSNP-DASH) are introduced. The platform's goal is to usher video as a data element that can be integrated into traditional and non-Internet networks. A low cost, scalable node is built from the ground up to be fully compatible with the Internet of Things Machine to Machine (M2M) concept, as well as the ability to be easily re-targeted to new applications in a short time. Flexi-WVSNP design includes a multi-radio node, a middle-ware for sensor operation and communication, a cross platform client facing data retriever/player framework, scalable security as well as a cohesive but decoupled hardware and software design.Dissertation/ThesisDoctoral Dissertation Electrical Engineering 201

    Domain specific high performance reconfigurable architecture for a communication platform

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    The card-centric framework: towards a new era of smart card applications.

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    by Chan, Pak Kee.Thesis (M.Phil.)--Chinese University of Hong Kong, 2004.Includes bibliographical references (leaves 78-81).Abstracts in English and Chinese.ABSTRACT OF THIS THESIS ENTITLED: --- p.I摘要 --- p.IIIAcknowledgements --- p.IVTable of Contents --- p.VList of Tables --- p.VIIList of Figures --- p.VIIIChapter CHAPTER 1 --- INTRODUCTION --- p.1Chapter 1.1 --- Overview --- p.1Chapter 1.2 --- Memory and Microprocessor Cards --- p.2Chapter 1.3 --- State-of-the-Art Smart Card Hardware --- p.3Chapter 1.4 --- Traditional Smart Card Applications --- p.5Chapter 1.5 --- IS07816: A Standard for Smart Cards --- p.6Chapter 1.6 --- Proactive SIM: Enlightens a New Way --- p.7Chapter 1.7 --- The Intelligent Adjunct Model: Smart Card be a Peer --- p.10Chapter 1.8 --- Motivations: Smart Cards to Run Any Applications --- p.11Chapter 1.9 --- Organization of this Thesis --- p.12Chapter CHAPTER 2 --- CARD-CENTRIC FRAMEWORK --- p.14Chapter 2.1 --- Overview --- p.14Chapter 2.2 --- System Model --- p.16Chapter 2.2.1 --- System Components --- p.17Chapter 2.2.2 --- Object Allocation --- p.25Chapter 2.3 --- Card-Centric Protocol --- p.27Chapter 2.3.1 --- Protocol Layering --- p.28Chapter 2.3.2 --- Message Format --- p.30Chapter 2.3.3 --- Handshake sequence --- p.33Chapter 2.4 --- Accessing On-card Resources by Console --- p.36Chapter 2.5 --- Interfaces --- p.39Chapter CHAPTER 3 --- SMART CARD APPLICATION DESIGN METHODOLOGY --- p.42Chapter 3.1 --- Overview --- p.42Chapter 3.2 --- The Event Driven Programming Model --- p.43Chapter 3.3 --- Terminal Application --- p.44Chapter 3.4 --- On-card Application --- p.47Chapter 3.5 --- From Linear Program to Finite State Machine --- p.49Chapter 3.6 --- Steps for On-Card Application Development --- p.52Chapter CHAPTER 4 --- SYSTEM PROTOTYPE: A SMART CARD-BASED SYSTEM --- p.55Chapter 4.1 --- Overview --- p.55Chapter 4.2 --- Hardware --- p.56Chapter 4.3 --- Software --- p.57Chapter 4.3.1 --- Program Flow --- p.57Chapter 4.3.2 --- Interface Objects --- p.61Chapter 4.3.3 --- Game Engine --- p.62Chapter 4.4 --- Performance --- p.66Chapter CHAPTER 5 --- IMPLEMENTATION ON FPGA --- p.69Chapter 5.1 --- Overview --- p.69Chapter 5.2 --- Configurations --- p.70Chapter 5.2.1 --- Hardware --- p.70Chapter 5.2.2 --- Software --- p.71Chapter 5.3 --- Performance --- p.73Chapter CHAPTER 6 --- CONCLUSIONS AND FUTURE WORKS --- p.75REFERENCES --- p.78DESIGN LIBRARIES - CDROM --- p.8

    Low power architectures for streaming applications

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