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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.
121

Reconfigurable wavelet-based architecture for pattern recognition applications using a field programmable gate array

Al-aqeeli, Abulqadir January 1998 (has links)
No description available.
122

A Secure Adaptive Network Processor

Harper, Scott Jeffery 03 July 2003 (has links)
Network processors are becoming a predominant feature in the field of network hardware. As new network protocols emerge and data speeds increase, contemporary general-purpose network processors are entering their second generation and academic research is being actively conducted into new techniques for the design and implementation of these systems. At the same time, systems ranging from secured military communications equipment to consumer devices are being updated to provide network connectivity. Many of these devices require, or would benefit from, the inclusion of device security in addition to data security. Whether it is a top-secret encryption scheme that must be concealed or a personal device that needs protection against unauthorized use, security of the device itself is becoming an important factor in system design. Unfortunately, current network processor solutions were not developed with device security in mind. A secure adaptive network processor can provide the means to fill this gap while continuing to provide full support for emerging communication protocols. This dissertation describes the concept and structure of one such device. Analysis of the hardware security provided by the proposed device is provided to highlight strengths and weaknesses, while a prototype system is developed to allow it to be embedded into practical applications for investigation. Two such applications are developed, using the device to provide support for both a secure network edge device and a user-adaptable network gateway. Results of these experiments indicate that the proposed device is useful both as a hardware security measure and as a basis for user adaptation of information-handling systems. / Ph. D.
123

Structured Approach to Dynamic Computing Application Development

Craven, Stephen Douglas 12 June 2008 (has links)
The ability of some configurable logic devices to modify their hardware during operation has long held great potential to increase performance and reduce device cost. However, despite many research projects and a decade of research, the dynamic reconfiguration of Field Programmable Gate Arrays (FPGAs) is still very much an art practiced by few. Previous attempts to automate the many low-level details that complicate Run-Time Reconfigurable (RTR) application development suffer severe limitations. This dissertation describes a comprehensive approach to dynamic hardware development, providing a designer with appropriate models for computation, communication, and reconfiguration integrated with a high-level design environment. In this way, many manual and time consuming tasks associated with partial reconfiguration are hidden, permitting a designer to focus instead on a design's behavior. This design and implementation environment has been validated on a variety of relevant applications, quantifying the effects of high-level design. / Ph. D.
124

Reconfigurable Hardware-Based Simulation Modeling of Flexible Manufacturing Systems

Tang, Wei 09 December 2005 (has links)
This dissertation research explores a reconfigurable hardware-based parallel simulation mechanism that can dramatically improve the speed of simulating the operations of flexible manufacturing systems (FMS). Here reconfigurable hardware-based simulation refers to running simulation on a reconfigurable hardware platform, realized by Field Programmable Gate Array (FPGA). The hardware model, also called simulator, is specifically designed for mimicking a small desktop FMS. It is composed of several micro-emulators, which are capable of mimicking operations of equipment in FMS, such as machine centers, transporters, and load/unload stations. To design possible architectures for the simulator, a mapping technology is applied using the physical layout information of an FMS. Under such a mapping method, the simulation model is decomposed into a cluster of micro emulators on the board where each machine center is represented by one micro emulator. To exploit the advantage of massive parallelism, a kind of star network architecture is proposed, with the robot sitting at the center. As a pilot effort, a prototype simulator has been successfully built. A new simulation modeling technology named synchronous real-time simulation (SRS) is proposed. Instead of running conventional programs on a microprocessor, this new technology adopts several concepts from electronic area, such as using electronic signals to mimic the behavior of entities and using specifically designed circuits to mimic system resources. Besides, a time-scaling simulation method is employed. The method uses an on-board global clock to synchronize all activities performed on different emulators, and by this way tremendous overhead on synchronization can be avoided. Experiments on the prototype simulator demonstrate the validity of the new modeling technology, and also show that tremendous speedup compared to conventional software-based simulation methods can be achieved. / Ph. D.
125

Incremental Design Techniques with Non-Preemptive Refinement for Million-Gate FPGAs

Ma, Jing 22 January 2003 (has links)
This dissertation presents a Field Programmable Gate Array (FPGA) design methodology that can be used to shorten the FPGA design-and-debug cycle, especially as gate counts increase to many millions. Core-based incremental placement algorithms, in conjunction with fast interactive routing, are investigated to reduce the design processing time by distinguishing the changes between design iterations and reprocessing only the changed blocks without affecting the remaining part of the design. Different from other incremental placement algorithms, this tool provides the function not only to handle small modifications; it can also incrementally place a large design from scratch at a rapid rate. Incremental approaches are inherently greedy techniques, but when combined with a background refinement thread, the incremental approach offers the instant gratification that designers expect, while preserving the fidelity attained through batch-oriented programs. An incremental FPGA design tool has been developed, based on the incremental placement algorithm and its background refiner. Design applications with logical gate sizes varying from tens of thousands to approximately one million are built to evaluate the execution of the algorithms and the design tool. The results show that this incremental design tool is two orders of magnitude faster than the competing approaches such as the Xilinx M3 tools without sacrificing much quality. The tool presented places designs at the speed of 700,000 system gates per second. The fast processing speed and user-interactive property make the incremental design tool potentially useful for prototype developing, system debugging and modular testing in million-gate FPGA designs. / Ph. D.
126

Implementing Scientific Simulation Codes Tailored for Vector Architectures Using Custom Configurable Computing Machines

Rutishauser, David 05 May 2011 (has links)
Prior to the availability of massively parallel supercomputers, the implementation of choice for scientific computing problems such as large numerical physical simulations was typically a vector supercomputer. Legacy code still exists optimized for vector supercomputers. Rehosting legacy code often requires a complete re-write of the original code, which is a long and expensive effort. This work provides a framework and approach to utilize reconfigurable computing resources in place of a vector supercomputer towards the implementation of a legacy source code without a large re-hosting effort. The choice of a vector processing model constrains the solution space such that practical solutions to the underlying resource constrained scheduling problem are achieved. Reconfigurable computing resources that implement capabilities characteristic of the application's original target platform are examined. The framework includes the following components: (1) a template for a parameterized, configurable vector processing core, (2) a scheduling and allocation algorithm that employs lessons learned from the mature knowledge base of vector supercomputing, and (3) the design of the VectCore co-processor to provide a low-overhead interface and control method for instances of the architectural template. The implementation approach applies the framework to produce VectCore instances tailored for specific input problems that meet resource constraints. Experimental data shows the VectCore approach results in efficient implementations with favorable performance compared to both general purpose processing and fixed vector architecture alternatives for the majority of the benchmark cases. Half the benchmark cases scale nearly linearly under a fixed time scaling model. The fixed workload scaling is also linear for the same cases until becoming constant for a subset of the benchmarks due to resource contention in the VectCore implementation limiting the maximum achievable parallelism. The architectural template contributed by this work supports established vector performance enhancing techniques such as parallel and chained operations. As the hardware resources are scaled, the VectCore approach scales the amount of parallelism applied in a problem implementation. In end-to-end hardware experiments, the VectCore co-processor overhead is shown to be small (less than 4%) compared to the schedule length. / Ph. D.
127

Design and Implementation of an FPGA-based Partially Reconfigurable Network Controller

Chaubal, Aditya Prakash 03 September 2004 (has links)
There is currently a strong trend towards embedding Internet capabilities into electronics and everyday appliances. Most network controllers used in small appliances or for specialized purposes are built using micro controllers. However there are many applications where a hardware-oriented approach using Application Specific Integrated Circuits (ASICs) or Field Programmable Gate Arrays (FPGAs) is more suitable. One of the features of FPGAs that cannot be integrated into ASICs is runtime reconfiguration in which, certain portions of the chip are reconfigured at runtime while the other parts continue to operate normally. This feature is required for network controllers with multiple data transfer channels that need to preserve the state of the static channels while reconfiguration is taking place. It is also required for controllers with space constraints in terms of FPGA resources or time constraints in terms of reconfiguration times. This thesis explores the impact of partial reconfiguration on the performance of a network controller. An FPGA-based network controller that supports partial reconfiguration has been designed and constructed. Partial bitstreams that can configure certain channels of the network controller without a ecting the functioning of others have been created. Experiments have been performed that quantify the manner in which, the performance of the controller can be changed by loading these partial bitstreams onto the FPGA. These experiments demonstrated the advantages of using partial reconfiguration to change network-related parameters at runtime to optimize performance of the network controller. / Master of Science
128

Enhancing GNU Radio for Run-Time Assembly of FPGA-Based Accelerators

Stroop, Richard Henry Lee 17 September 2012 (has links)
Software defined radios (SDRs) have changed the paradigm of slowly designing custom radios, instead allowing designers to quickly iterate designs with a large range of functionality. With the help of environments like the open-source project, GNU Radio, a designer can prototype radios with greatly improved productivity. Unfortunately, due to software performance limitations, there is no way to achieve the range of radio designs made possible with actual physical radio hardware. In order for SDRs to become more prevalent in radio prototyping and development, accelerators must be added to high-throughput and computationally intensive portions. Custom DSPs, GPUs, and FPGAs have all been added to SDRs to try and expand their computational capabilities. One difficulty in this is that by adding these accelerators, the "instant gratification" dynamic of the GNU Radio is lost. In this thesis, an enhanced GNU Radio flow is presented that seamlessly augments the GNU Radio software-only model with FPGAs, yet preserves the GNU Radio dynamics by providing full-custom radio hardware/software structures in seconds. By delegating portions of a GNU Radio flow graph to networked FPGAs, a larger class of software-defined radios can be implemented. Assembly of the signal processing structures within the FPGAs is accomplished using an enhanced flow where modules are customized, placed, and routed in a fraction of the time required by the vendor tools. With rapid FPGA assembly, a GNU Radio designer retains the ability to perform "what-if" experiments, which in turn greatly enhances productivity. Due to the modular nature of GNU Radio and of the FPGA designs, a modular assembly of the FPGA hardware is used. In the flow presented here, optimized hardware library components are designed by a domain expert, and stored as compact placed-and-routed modules. When a designer requests the assembly of one or more components within a given FPGA via a GNU Radio Python script, the necessary library components are accessed and translated to an appropriate location within the chip. Then the ports of the modules are stitched together using a custom FPGA router. This process reduces the large compile times of hardware for an FPGA to reasonable software-like times. To the radio designer, the complexity of the underlying hardware is abstracted away, making it appear as if everything compiles and runs in software, allowing many iterations to be realized quickly. Radio design can continue at the speeds that GNU Radio designers are accustomed to but with the range of possible waveforms and general functionality extended. / Master of Science
129

Stream Communication and Computation in the Eight-meter-wavelength Transient Array (ETA) Radio Telescope

Martin, Brian Scott 11 November 2008 (has links)
The Eight-meter-wavelength Transient Array (ETA) system is a unique implementation of an array-based radio telescope. The instrument is designed to further astronomy by detecting and characterizing dispersed pulses received between 29–47 MHz. To aid data processing of radio signals received through 24 antennas, the ETA system performs real-time stream processing as data is passed from antennas to hard disk storage. The processing includes digital sampling, downconversion, filtering, Fast Fourier Transforms, and beamforming operations and is performed by 28 commercial-off-the-shelf (COTS) FPGA boards. Sixteen of the FPGA boards constitute the reconfigurable computing cluster (RCC) which performs the FFT and beamforming operations and is the focus of this thesis. The FPGA-based architecture allows the RCC to provide the high computational and communication throughput required by the ETA system. In addition, the FPGA design allows for a custom processing data path, parallel processing, global synchronization, and rapid development at a low cost. / Master of Science
130

A Physical Layer Implementation of Reconfigurable Radio

Bhatia, Nikhil S. 10 December 2004 (has links)
The next generation of wireless communications will demand the use of software radio technology as the basic architecture to support multi-standard, multi-mode and future-proof radio designs. Software-defined radios are configurable devices in which the physical layer can be reprogrammed to support various standards. Field programmable architectures provide a suitable platform to achieve such run-time reconfigurations of the physical layer of the radio. This thesis explores the use of FPGAs in the design of reconfigurable radios. The results presented here demonstrate how FPGAs can be used to provide the flexibility, performance, efficiency and better resource utilization while meeting the speed and area constraints set by a particular design. The partial reconfiguration feature available in the state-of-the art FPGAs has been exploited to implement the baseband physical layer of reconfigurable radio which can be altered to support various modulations schemes for different wireless standards. The design flow for partial reconfiguration along with the implementation results on two different FPGA platforms is presented. The experiments presented in this thesis make use of System Generator for DSP, a productivity tool from Xilinx, to design and to simulate system-level models in a MATLAB/Simulink environment, and to obtain timing and resource utilization results before implementing the design on actual hardware. / Master of Science

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