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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
271

Architectural Solutions for Low-power, Low-voltage, and Unreliable Silicon Devices

Miller, Timothy Normand 22 June 2012 (has links)
No description available.
272

Single Event Upset error detection on routing tracks of Xilinx FPGAs

Taj, Billy 24 September 2014 (has links)
<p>This thesis proposes a new method to detect routing switch alterations on FPGAs in real-time. By sampling the circuit path at the source and destination, and comparing the samples, it is possible to find out if there has been a routing change in the circuit path. We compare and contrast this probing method with previously established techniques such as Cyclic Redundancy Checks, Built-in-self-tests, Triple Modular Redundancy, Duplication with Comparison, and redesigning the FPGA. The probe method finds the routing error in one clock cycle, using the pre-existing elements on the FPGA, while the FPGA is still operational. This method works on all FPGAs that use the Wilton style switchbox. An automated tool for probing the design circuit is presented in this thesis that applies the probe scheme on a circuit built on the Xilinx Virtex-4 FPGA.</p> / Master of Applied Science (MASc)
273

Fabrication et caractérisation de transistor réalisée à basse température pour l'intégration 3D séquentielle / Fabrication and Characterisation of low temperature transistors for 3D integration

Micout, Jessy 08 March 2019 (has links)
La réduction des dimensions des dispositifs MOSFET devient de plus en plus complexe a réalisé, et les nouvelles technologies MOSFET se confrontent à de fortes difficultés. Pour surmonter ce problème, une nouvelle technique, appelée intégration 3D VLSI, est étudiée : remplacer la structure plane conventionnelle par un empilement vertical de transistors.En particulier, l’intégration 3D séquentielle ou CoolCube™ au CEA-Leti permet de profiter pleinement de la troisième dimension en fabriquant séquentiellement les transistors. La réalisation d’une telle intégration apporte une nouvelle contrainte, celle de fabriquer le transistor du dessus avec un budget thermique faible (inférieur à 500°C), afin de préserver les performances du transistor d'en dessous. Puisque ce budget thermique est principalement influencé par l'activation des dopants, plusieurs techniques innovatrices sont actuellement investiguées au CEA-LETI, afin de fabriquer le drain et la source. Dans ce manuscrit, nous utiliserons la recristallisation en phase solide comme mécanisme pour activer les dopants (inférieures à 600 °C). L’objectif de cette thèse est donc de fabriquer et de caractériser des transistors dont l’activation des dopants est réalisée grâce à ce mécanisme, afin d’atteindre des performances similaires à des transistors réalisés avec un budget thermique standard. Ce travail est organisé autour de l’activation des dopants, et en trois chapitres, où chaque chapitre est spécifique à une intégration (« Extension Last »/ « Extension First », « Gate Last »/ « Gate First ») et à une architecture (FDSOI, FINFET) considérées. Ces chapitre permettront, grâce aux caractérisations électriques, morphologiques et aux simulations, de développer un procédé de recristallisation stable à 500°C, à la fois pour les nMOS et les pMOS, et de proposer de nouveaux schémas d’intégrations, afin de réaliser des transistors à faible budget thermique et compatibles avec l’intégration 3D Séquentielle. / The down scaling of MOSFET device is becoming harder and the development of future generation of MOSFET technology is facing some strong difficulties. To overcome this issue, the vertical stacking of MOSFET in replacement of the conventional planar structure is currently investigated. This technique, called 3D VLSI integration, attracts a lot of attention, in research and in the industry. Indeed, this sequential stacking of transistor enables to gain in density and performance without reducing transistors dimensions.More specifically, 3D sequential integration or CoolCube™ at CEA-Leti enables to fully benefit of the third dimension by sequentially manufacturing transistors. Implementing such an integration provides the new constraint of manufacturing top transistor with low thermal budget (below 500°C) in order to preserve bottom-transistor performances. As most of the thermal budget is due to the dopant activation, several innovative techniques are currently investigated at CEA-LETI.In this work, solid phase epitaxy regrowth will be used as the mechanism to activate dopants below 600°C. The aim of this thesis is thus to manufacture and to characterize transistors with low-temperature dopant activation, in order to reach the same performance as devices manufactured with standard thermal budget. The work is organized around the dopant activation, and in three chapters, according to each considered integration scheme (Extension Last/ Extension First, Gate Last/ Gate First) and architecture (FDSOI, FINFET). These chapters, assisted by relevant simulations, electrical and morphological characterizations, will enable to develop a new and stable 500°C recrystallization process for both N and P FETs, and to propose new integration schemes in order to manufacture transistors with low thermal budget and compatible with the 3D sequential integration.
274

A New Method To Determine Optimal Time-Delays Between Switching Of Digital VLSI Circuits To Minimize Power Supply Noise

Srinivasan, G 06 1900 (has links)
Power supply noise, which is the variation in the supply voltage across the on-die supply terminals of VLSI circuits, is a serious performance degrader in digital circuits and mixed analog-digital circuits. In digital VLSI systems, power supply noise causes timing errors such as delays, jitter, and false switching. In microprocessors, power supply noise reduces the maximum operating frequency (FMAX) of the CPU. In mixed analog-digital circuits, power supply noise manifests as the substrate noise and impairs the performance of the analog portion. The decrease in the available noise margin with the decrease in the feature size of transistors in CMOS systems makes the power supply noise a very serious issue, and demands new methods to reduce the power supply noise in sub-micron CMOS systems. In this thesis, we develop a new method to determine optimal time-delays between the switching of input/output (I/O) data buffers in digital VLSI systems that realizes maximum reduction of the power supply noise. We first discuss methods to characterize the distributed nature of the Power Delivery Network (PDN) in the frequency-domain. We then develop an analytical method to determine the optimal delays using the frequency-domain response of the PDN and the supply current spectrum of the buffer units. We explain the mechanism behind the cancellation of the power supply noise by the introduction of optimal buffer-to-buffer delays. We also develop a numerical method to determine the optimal delays and compare it with the analytical method. We illustrate the reduction in the power supply noise by applying the optimal time-delays determined using our methods to two examples of PDN. Our method has great potential to realize maximum reduction of power supply noise in digital VLSI circuits and substrate noise in mixed analog-digital VLSI circuits. Lower power supply noise translates into lower cost and improved performance of the circuit.
275

Υλοποίηση VLSI αρχιτεκτονικής με ψηφιακά φίλτρα για ασύρματο OFDM Modem

Κολοβός, Παύλος 08 October 2007 (has links)
Η μετάδοση δεδομένων µέσω ασύρματων δικτύων αποτελεί ένα από τα σημαντικότερα αντικείμενα μελέτης στον χώρο των τηλεπικοινωνιών τα τελευταία χρόνια. Λόγω του μεγάλου όγκου δεδομένων που απαιτείται για μετάδοση μέσα σε πολύ μικρό χρονικό διάστημα, απαιτείται η εφαρμογή όσο το δυνατόν αποδοτικότερης κωδικοποίησης και διαμόρφωσης, σκοπεύοντας παράλληλα στην επίτευξη μικρής κατανάλωσης ισχύος και ταυτόχρονα υψηλού throughput. Η παρούσα διπλωματική εργασία πραγματεύεται τη μελέτη, σχεδίαση και την υλοποίηση της αρχιτεκτονικής ενός OFDM συστήματος, βασισμένο στις προδιαγραφές που ορίζει το πρότυπο IEEE802.11. Το πρότυπο αυτό επιλέχθηκε, καθώς τυγχάνει ευρείας αποδοχής, όσον αφορά τη μετάδοση δεδομένων σε ασύρματα δίκτυα. Στα πλαίσια της διπλωματικής παρουσιάζονται εξομοιώσεις και μετρήσεις για την εύρεση των κατάλληλων χαρακτηριστικών και του τύπου των φίλτρων που χρησιμοποιούνται σε ένα OFDM σύστημα, ενώ εισάγονται δύο νέες αρχιτεκτονικές του τμήματος κατασκευής του OFDM συμβόλου, καθώς και τα αποτελέσματα της σύνθεσης αυτών. Ιδιαίτερη βαρύτητα δίνεται στη σχεδίαση και την υλοποίηση των αρχιτεκτονικών αυτών με σκοπό την ενσωμάτωσή τους σε συσκευές FPGA. / Transmission of data through wireless networks is one of the most important aspects in the study telecommunications systems. The large volume of data that needs to be transmitted in a very small time interval has resulted in the need to make the system more efficient while increasing the throughput. This has been accomplished through more efficient coding, reduction of the power consumption and through the use of modulation. This masters thesis deals with the study, design and implementation of the typical OFDM system architecture, based on the standard IEEE802.11. This standard was chosen because of its wide acceptance and use regarding transmission of data in wireless networks. The thesis details the adjustments and measurements needed for determining suitable characteristics and the types of filters required in an OFDM system. Additionally two new OFDM system architectures arte introduced aiming at reducing the overall power consumption and the complexity of the formulae used for symbol construction. Particular importance is given in the designing and the implementation of these architectures regarding their incorporation in FPGA devices.
276

VLSI architecture for motion estimation in underwater imaging

Ila, Viorela 14 November 2005 (has links)
El treball desenvolupat en aquesta tesi aprofundeix i aporta solucions innovadores en el camp orientat a tractar el problema de la correspondència en imatges subaquàtiques. En aquests entorns, el que realment complica les tasques de processat és la falta de contorns ben definits per culpa d'imatges esborronades; un fet aquest que es deu fonamentalment a il·luminació deficient o a la manca d'uniformitat dels sistemes d'il·luminació artificials. Els objectius aconseguits en aquesta tesi es poden remarcar en dues grans direccions. Per millorar l'algorisme d'estimació de moviment es va proposar un nou mètode que introdueix paràmetres de textura per rebutjar falses correspondències entre parells d'imatges. Un seguit d'assaigs efectuats en imatges submarines reals han estat portats a terme per seleccionar les estratègies més adients. Amb la finalitat d'aconseguir resultats en temps real, es proposa una innovadora arquitectura VLSI per la implementació d'algunes parts de l'algorisme d'estimació de moviment amb alt cost computacional. / Underwater robotics was the motivation of this work, even though computer vision and parallel VLSI architectures played the most important role. Due to their low cost, high-rate and high-resolution, vision based systems represent a good option to provide information about a vehicle position. The apparent motion of a camera mounted on an underwater vehicle can be estimated by correlating two successive frames of an image sequence. Lack of well-defined contours, as well as non-uniform illumination makes underwater scenes much more difficult to be processed than normal images. Therefore, methods frequently used in standard image processing must be modified and adapted to these particular conditions. A method based on texture characterisation of points to reject outliers from the image correspondence problem is proposed. On the other hand, a parallel implementation was used to speed-up parts of the motion estimation algorithm which have a computationally high load. A new VLSI architecture is proposed with the aim of achieving frame-rate performance.
277

Projeto da arquitetura de hardware para binarização e modelagem de contextos para o CABAC do padrão de compressão de vídeo H.264/AVC / Hardware architecture design for binarization and context modeling for CABAC of H.264/AVC video compression

Martins, André Luis Del Mestre January 2011 (has links)
O codificador aritmético binário adaptativo ao contexto adotado (CABAC – Context-based Adaptive Binary Arithmetic Coding) pelo padrão H.264/AVC a partir de perfil Main é o estado-da-arte em termos de eficiência de taxa de bits. Entretanto, o CABAC ocupa 9.6% do tempo total de processamento e seu throughput é limitado pelas dependências de dados no nível de bit (LIN, 2010). Logo, atingir os requisitos de desempenho em tempo real nos níveis mais altos do padrão H.264/AVC se torna uma tarefa árdua em software, sendo necesário então, a aceleração do CABAC através de implementações em hardware. As arquiteturas de hardware encontradas na literatura para o CABAC focam no Codificador Aritmético Binário (BAE - Binary Arithmetic Encoder) enquanto que a Binarização e Modelagem de Contextos (BCM – Binarization and Context Modeling) fica em segundo plano ou nem é apresentada. O BCM e o BAE juntos constituem o CABAC. Esta dissertação descreve detalhadamente o conjunto de algoritmos que compõem o BCM do padrão H.264/AVC. Em seguida, o projeto de uma arquitetura de hardware específica para o BCM é apresentada. A solução proposta é descrita em VHDL e os resultados de síntese mostram que a arquitetura alcança desempenho suficiente, em FPGA e ASIC, para processar vídeos no nível 5 do padrão H.264/AVC. A arquitetura proposta é 13,3% mais rápida e igualmente eficiente em área que os melhores trabalhos relacionados nestes quesitos. / Context-based Adaptive Binary Arithmetic Coding (CABAC) adopted in the H.264/AVC main profile is the state-of-art in terms of bit-rate efficiency. However, CABAC takes 9.6% of the total encoding time and its throughput is limited by bit-level data dependency (LIN, 2010). Moreover, meeting real-time requirement for a pure software CABAC encoder is difficult at the highest levels of the H.264/AVC standard. Hence, speeding up the CABAC by hardware implementation is required. The CABAC hardware architectures found in the literature focus on the Binary Arithmetic Encoder (BAE), while the Binarization and Context Modeling (BCM) is a secondary issue or even absent in the literature. Integrated, the BCM and the BAE constitute the CABAC. This dissertation presents the set of algorithms that describe the BCM of the H.264/AVC standard. Then, a novel hardware architecture design for the BCM is presented. The proposed design is described in VHDL and the synthesis results show that the proposed architecture reaches sufficiently high performance in FPGA and ASIC to process videos in real-time at the level 5 of H.264/AVC standard. The proposed design is 13.3% faster than the best works in these items, while being equally efficient in area.
278

Projeto da arquitetura de hardware para binarização e modelagem de contextos para o CABAC do padrão de compressão de vídeo H.264/AVC / Hardware architecture design for binarization and context modeling for CABAC of H.264/AVC video compression

Martins, André Luis Del Mestre January 2011 (has links)
O codificador aritmético binário adaptativo ao contexto adotado (CABAC – Context-based Adaptive Binary Arithmetic Coding) pelo padrão H.264/AVC a partir de perfil Main é o estado-da-arte em termos de eficiência de taxa de bits. Entretanto, o CABAC ocupa 9.6% do tempo total de processamento e seu throughput é limitado pelas dependências de dados no nível de bit (LIN, 2010). Logo, atingir os requisitos de desempenho em tempo real nos níveis mais altos do padrão H.264/AVC se torna uma tarefa árdua em software, sendo necesário então, a aceleração do CABAC através de implementações em hardware. As arquiteturas de hardware encontradas na literatura para o CABAC focam no Codificador Aritmético Binário (BAE - Binary Arithmetic Encoder) enquanto que a Binarização e Modelagem de Contextos (BCM – Binarization and Context Modeling) fica em segundo plano ou nem é apresentada. O BCM e o BAE juntos constituem o CABAC. Esta dissertação descreve detalhadamente o conjunto de algoritmos que compõem o BCM do padrão H.264/AVC. Em seguida, o projeto de uma arquitetura de hardware específica para o BCM é apresentada. A solução proposta é descrita em VHDL e os resultados de síntese mostram que a arquitetura alcança desempenho suficiente, em FPGA e ASIC, para processar vídeos no nível 5 do padrão H.264/AVC. A arquitetura proposta é 13,3% mais rápida e igualmente eficiente em área que os melhores trabalhos relacionados nestes quesitos. / Context-based Adaptive Binary Arithmetic Coding (CABAC) adopted in the H.264/AVC main profile is the state-of-art in terms of bit-rate efficiency. However, CABAC takes 9.6% of the total encoding time and its throughput is limited by bit-level data dependency (LIN, 2010). Moreover, meeting real-time requirement for a pure software CABAC encoder is difficult at the highest levels of the H.264/AVC standard. Hence, speeding up the CABAC by hardware implementation is required. The CABAC hardware architectures found in the literature focus on the Binary Arithmetic Encoder (BAE), while the Binarization and Context Modeling (BCM) is a secondary issue or even absent in the literature. Integrated, the BCM and the BAE constitute the CABAC. This dissertation presents the set of algorithms that describe the BCM of the H.264/AVC standard. Then, a novel hardware architecture design for the BCM is presented. The proposed design is described in VHDL and the synthesis results show that the proposed architecture reaches sufficiently high performance in FPGA and ASIC to process videos in real-time at the level 5 of H.264/AVC standard. The proposed design is 13.3% faster than the best works in these items, while being equally efficient in area.
279

?Algoritmos e Arquiteturas VLSI para Detectores MIMO com Decis?o Suave

Duarte, Jos? Marcelo Lima 17 August 2012 (has links)
Made available in DSpace on 2015-03-03T15:08:47Z (GMT). No. of bitstreams: 1 JoseMLD_TESE.pdf: 1767414 bytes, checksum: b0bb7821ad5c80023e5752938c7e5922 (MD5) Previous issue date: 2012-08-17 / The use of Multiple Input Multiple Output (MIMO) systems has permitted the recent evolution of wireless communication standards. The Spatial Multiplexing MIMO technique, in particular, provides a linear gain at the transmission capacity with the minimum between the numbers of transmit and receive antennas. To obtain a near capacity performance in SM-MIMO systems a soft decision Maximum A Posteriori Probability MIMO detector is necessary. However, such detector is too complex for practical solutions. Hence, the goal of a MIMO detector algorithm aimed for implementation is to get a good approximation of the ideal detector while keeping an acceptable complexity. Moreover, the algorithm needs to be mapped to a VLSI architecture with small area and high data rate. Since Spatial Multiplexing is a recent technique, it is argued that there is still much room for development of related algorithms and architectures. Therefore, this thesis focused on the study of sub optimum algorithms and VLSI architectures for broadband MIMO detector with soft decision. As a result, novel algorithms have been developed starting from proposals of optimizations for already established algorithms. Based on these results, new MIMO detector architectures with configurable modulation and competitive area, performance and data rate parameters are here proposed. The developed algorithms have been extensively simulated and the architectures were synthesized so that the results can serve as a reference for other works in the area / O uso de sistemas de M?ltiplas Entradas e M?ltiplas Sa?das (Multiple Input Multiple Output - MIMO) tem permitido a recente evolu??o dos novos padr?es de comunica??o m?vel. A t?cnica MIMO da Multiplexa??o Espacial, em particular, prov? um aumento linear na capacidade de transmiss?o com o m?nimo entre n?mero de antenas transmissoras e antenas receptoras. Para se obter um desempenho pr?ximo a capacidade em sistemas com Multiplexa??o Espacial faz-se necess?rio o uso de um detector MIMO com decis?o suave do tipo Maximum A Posteriori Probability. Entretanto, tal detector e muito complexo para solu??es pr?ticas. Assim, o objetivo dos algoritmos de detec??o MIMO voltados para implementa??o e obter uma boa aproxima??o do detector ideal mantendo um n?vel de complexidade aceit?vel. Al?m disso, o algoritmo precisa ser mapeado para uma arquitetura VLSI de ?rea pequena e que atenda a taxa de transmiss?o exigida pelos padr?es de comunica??es m?veis. Sendo a multiplexa??o espacial uma t?cnica recente, defende-se que ainda h? muito espa?o para evolu??o dos algoritmos e arquiteturas relacionadas. Por isso, esta tese se focou no estudo de algoritmos sub-?timos e arquiteturas VLSI para detectores MIMO de banda larga com decis?o suave. Como resultado, algoritmos in?ditos foram desenvolvidos partindo de propostas de otimiza??es para algoritmos j? estabelecidos. Baseado nesses resultados, novas arquiteturas de detectores MIMO com modula??o configur?vel e competitivos par?metros de ?rea, desempenho e taxa de processamento s?o aqui propostas. Os algoritmos desenvolvidos foram extensivamente simulados e as arquiteturas sintetizadas para que os resultados pudessem servir como refer?ncia para outros trabalhos na ?rea.
280

Projeto da arquitetura de hardware para binarização e modelagem de contextos para o CABAC do padrão de compressão de vídeo H.264/AVC / Hardware architecture design for binarization and context modeling for CABAC of H.264/AVC video compression

Martins, André Luis Del Mestre January 2011 (has links)
O codificador aritmético binário adaptativo ao contexto adotado (CABAC – Context-based Adaptive Binary Arithmetic Coding) pelo padrão H.264/AVC a partir de perfil Main é o estado-da-arte em termos de eficiência de taxa de bits. Entretanto, o CABAC ocupa 9.6% do tempo total de processamento e seu throughput é limitado pelas dependências de dados no nível de bit (LIN, 2010). Logo, atingir os requisitos de desempenho em tempo real nos níveis mais altos do padrão H.264/AVC se torna uma tarefa árdua em software, sendo necesário então, a aceleração do CABAC através de implementações em hardware. As arquiteturas de hardware encontradas na literatura para o CABAC focam no Codificador Aritmético Binário (BAE - Binary Arithmetic Encoder) enquanto que a Binarização e Modelagem de Contextos (BCM – Binarization and Context Modeling) fica em segundo plano ou nem é apresentada. O BCM e o BAE juntos constituem o CABAC. Esta dissertação descreve detalhadamente o conjunto de algoritmos que compõem o BCM do padrão H.264/AVC. Em seguida, o projeto de uma arquitetura de hardware específica para o BCM é apresentada. A solução proposta é descrita em VHDL e os resultados de síntese mostram que a arquitetura alcança desempenho suficiente, em FPGA e ASIC, para processar vídeos no nível 5 do padrão H.264/AVC. A arquitetura proposta é 13,3% mais rápida e igualmente eficiente em área que os melhores trabalhos relacionados nestes quesitos. / Context-based Adaptive Binary Arithmetic Coding (CABAC) adopted in the H.264/AVC main profile is the state-of-art in terms of bit-rate efficiency. However, CABAC takes 9.6% of the total encoding time and its throughput is limited by bit-level data dependency (LIN, 2010). Moreover, meeting real-time requirement for a pure software CABAC encoder is difficult at the highest levels of the H.264/AVC standard. Hence, speeding up the CABAC by hardware implementation is required. The CABAC hardware architectures found in the literature focus on the Binary Arithmetic Encoder (BAE), while the Binarization and Context Modeling (BCM) is a secondary issue or even absent in the literature. Integrated, the BCM and the BAE constitute the CABAC. This dissertation presents the set of algorithms that describe the BCM of the H.264/AVC standard. Then, a novel hardware architecture design for the BCM is presented. The proposed design is described in VHDL and the synthesis results show that the proposed architecture reaches sufficiently high performance in FPGA and ASIC to process videos in real-time at the level 5 of H.264/AVC standard. The proposed design is 13.3% faster than the best works in these items, while being equally efficient in area.

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