The configurable computing research community has provided a wealth of evidence that computational platforms based on FPGA technology are capable of cost-effectively accelerating certain kinds of computations. One actively growing area in the research community examines the benefits to computation that can be gained by reconfiguring the FPGAs in a system during the execution of an application. This technique is commonly referred to as run-time reconfiguration. Widespread acceptance of run-time reconfigurable custom computing depends upon the existence of high-level automated design tools. Given the wide variety of available platforms and the rate that the technology is evolving, a set of architecturally independent tools that provide the ability to port applications between different architectures will allow application-based intellectual property to be easily migrated between platforms. A Java implementation of such a toolset, called Janus, is presented and analyzed here. In this environment, developers create a Java class that describes the structural behavior of an application. The design framework allows hardware and software modules to be freely intermixed. During the compilation phase of the development process, the Janus tools analyze the structure of the application and adapt it to the target architecture. Janus is capable of structuring the run-time behavior of an application to take advantage of the resources available on the platform. Examples of applications developed using the toolset are presented. The performance of the applications is reported. The retargeting of applications for multiple hardware architectures is demonstrated. / Ph. D.

The need for hardware-based software protection stems primarily from the increasing value of software coupled with the inability to trust software that utilizes or manages shared resources. By correctly utilizing security functions in hardware, trust can be removed from software. Existing hardware-based software protection solutions generally suffer from utilization of trusted software, lack of implementation, and/or extreme measures such as processor redesign. In contrast, the research outlined in this document proposes that substantial, hardware-based software protection can be achieved, without trusting software or redesigning the processor, by augmenting existing processors with security management hardware placed outside of the processor boundary. Benefits of this approach include the ability to add security features to nearly any processor, update security features without redesigning the processor, and provide maximum transparency to the software development and distribution processes. The major contributions of this research include the the augmentation methodology, design principles, and a graph-based method for analyzing hardware-based security systems. / Ph. D.

As VLSI circuits continue to have more and more transistors over time, the question of not only how to use, but how to manage the complexity of so many transistors becomes increasingly important. Four hypothesis are given for the design of a system that scales-up as transistors continue to shrink. An architecture is presented that satisfies these hypothesis, and the motivation behind the hypothesis is further explained. The use of this architecture's unique features to implement an efficient, defect-tolerant parallel bootstrap system is discussed. A detailed methodology for implementing this system in vivo is described. A sample problem--simulation of heat flow--is presented, and its solution using the proposed architecture is described in detail. A comparison is made between the proposed architecture and a set of contemporary architectures, and the former is shown to have desirable performance in a number of areas. Conclusion are given, and plans for future work are presented. / Ph. D.

The security of a radio system hinges on its ability to effectively authenticate a user. This work proposes a two-factor authentication scheme using a token and a biometric. The users' access rights are determined during authentication and the users are served only those channels of data that they are privileged to receive. The strengths and the weaknesses of the implementation in reconfigurable hardware are identified. The capabilities of the scheme are put into perspective by comparing it to a high-end authentication system and by evaluating the use of standardized APIs and low-end authentication devices. Modifications to the system are suggested to improve the level of security the scheme provides. Finally, a baseline study is carried out to measure the data processing performance of a radio developed in reconfigurable hardware, which uses the proposed authentication scheme. / Master of Science

Recent advancements in actuator technologies, computation, and control have led to major leaps in capability and have brought humanoids ever closer to being feasible solutions for real-world applications. As the capabilities of humanoids increase, they will be called on to operate in unstructured real world environments. This realization has driven researchers to develop more dynamic, robust, and adaptable robots. Compared to state-of-the-art robots, biological systems demonstrate remarkably better efficiency, agility, adaptability, and robustness. Many recent studies suggest that a core principle behind these advantages is compliance, yet there are very few compliant humanoids that have demonstrated successful walking. The work presented in this dissertation is based on several years of developing novel actuators for two full-scale linearly actuated compliant humanoid robots, SAFFiR and THOR. Both are state-of-the-art robots intended to operate in the extremely challenging real world scenarios of shipboard firefighting and disaster response. The design, modeling, and control of actuators in robotics application is critical because the rest of the robot is often designed around the actuators. This dissertation seeks to address two goals: 1) advancing the design of compliant linear actuators that are well suited for humanoid applications, and 2) developing a better understanding of how to design and model compliant linear actuators for use in humanoids. Beyond just applications for compliant humanoids, this research tackles many of the same design and application challenges as biomechanics research so it has many potential applications in prosthetics, exoskeletons, and rehabilitation devices. / Ph. D.

As Field Programmable Gate Arrays (FPGAs) continue to become integral parts of embedded systems, it is imperative to consider their security. While much of the research in this field is oriented toward the protection of the intellectual property contained in the FPGA's configuration, the protection of the design's integrity from malicious attack against the configuration is critical to the operation of the system. Methods for attacking the configuration are semi-invasive attacks, such as fault injection, and data tampering of incoming partial bitstreams. This thesis introduces methods for securing the integrity of an FPGA's configuration. The design and implementation is discussed for a system that consists of three parts. The first subsystem monitors the running configuration. The second subsystem authenticates partial bistreams that may be used for repairing the configuration from malicious alterations during run-time. The third subsystem indicates if the system itself succumbs to a malicious attack. The system is implemented on-chip, allowing the FPGA to effectively secure itself from attack. / Master of Science

Long wait times constitute a bottleneck limiting the number of compilation runs performed in a day, thus risking to restrict Field-Programmable Gate Array (FPGA) adaptation in modern computing platforms. This work presents an FPGA development paradigm that exploits logic variance and hierarchy as a means to increase FPGA productivity. The practical tasks of logic partitioning, placement and routing are examined and a resulting assembly framework, Quick Flow (qFlow), is implemented. Experiments show up to 10x speed-ups using the proposed paradigm compared to vendor tool flows. / Ph. D.

Adaptive computing systems have proven useful for implementing a wide range of algorithms. A limitation of current systems is the relatively small amount of reconfigurable hardware resources. Many algorithms require more hardware resources than are available. One solution to this problem is runtime reconfiguration (RTR). Using RTR techniques, a large algorithm is implemented as a collection of configurations for the reconfigurable hardware. These configurations are loaded onto the reconfigurable hardware as necessary to implement the algorithm. A primary limitation of RTR is that the reconfiguration process is slow. Therefore, methods of decreasing reconfiguration time are desirable. Another method of implementing large algorithms on small hardware is to use multiple configurable computing platforms connected via a communication network. RTR techniques can be used in conjunction with this method to further increase hardware availability. In this case reconfiguration time is increased by the overhead of transmitting data across the communication network. Methods of decreasing network overhead are desirable. This thesis discusses the use of caching techniques to decrease reconfiguration time. An architecture for caching configurations is implemented on a configurable computing system platform. The use of caching to decrease network overhead is discussed and exhibited. An example application is implemented and used to evaluate the effects of caching on reconfiguration time and algorithm performance. / Master of Science

The reprogrammable nature of configurable computing machines has led to a wealth of research in run-time reconfigurable systems and applications. A limitation often encountered in this research is the slow configuration time with respect to the system clock speed. One technique to deal with these configuration delays has been to develop devices that can hold multiple rapidly interchangeable configurations. This technique is known as context-switching. This thesis discusses the development of a framework to support applications which execute on a run-time reconfigurable system containing context-switching devices. The framework is divided into a number of layers: hardware, middleware, software, and applications. The design, implementation, and details of each layer are presented. / Master of Science

Genetic research projects currently can require enormous computing power to processes the vast quantities of data available. Further, DNA sequencing projects are generating data at an exponential rate greater than that of the development microprocessor technology; thus, new, faster methods and techniques of processing this data are needed. One common type of processing involves searching a sequence database for the most similar sequences. Here we present a distributed database search system that utilizes adaptive computing technologies. The search is performed using the Smith-Waterman algorithm, a common sequence comparison algorithm. To reduce the total search time, an initial search is performed using a version of the algorithm, implemented in adaptive computing hardware, which is designed to efficiently perform the initial search. A final search is performed using a complete version of the algorithm. This two-stage search, employing adaptive and distributed hardware, achieves a performance increase of several orders of magnitude over similar processor based systems. / Master of Science