221 research outputs found
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Behavioral synthesis from VHDL using structured modeling
This dissertation describes work in behavioral synthesis involving the development of a VHDL Synthesis System VSS which accepts a VHDL behavioral input specification and performs technology independent synthesis to generate a circuit netlist of generic components. The VHDL language is used for input and output descriptions. An intermediate representation which incorporates signal typing and component attributes simplifies compilation and facilitates design optimization.A Structured Modeling methodology has been developed to suggest standard VHDL modeling practices for synthesis. Structured modeling provides recommendations for the use of available VHDL description styles so that optimal designs will be synthesized.A design composed of generic components is synthesized from the input description through a process of Graph Compilation, Graph Criticism, and Design Compilation. Experiments were performed to demonstrate the effects of different modeling styles on the quality of the design produced by VSS. Several alternative VHDL models were examined for each benchmark, illustrating the improvements in design quality achieved when Structured Modeling guidelines were followed
Specifications and programs for computer software validation
Three software products developed during the study are reported and include: (1) FORTRAN Automatic Code Evaluation System, (2) the Specification Language System, and (3) the Array Index Validation System
A heterogeneous computer vision architecture: implementation issues
The prototype of a heterogeneous architecture is currently being built. The architecture is aimed at video-rate computing and is based on a message passing MIMD topology at the top level-transputer based-and on VLSI associative processor arrays (APA, SIMD structure) for low level image processing tasks. The APA structure is implemented through a set of 4 VLSI chips (GLiTCH) containing 64 1-bit processing elements each. This communication addresses some issues concerning the implementation of the first prototype, namely those related to:
• the design and integration of the APA controller unit, which provides the required interface between the APA, the MIMD topology and the video image interface:
• the evaluation of the GLiTCH chip through an emulator based on transputers and fast programmable devices; the emulator was designed to be flexible enough to evaluate later modifications to the GLiTCH design;
• the design of an integrated set of software development tools containing a structured editor-syntax oriented, with a visual interface/programming interface-and a cross compiler and debugger
Research in the effective implementation of guidance computers with large scale arrays Interim report
Functional logic character implementation in breadboard design of NASA modular compute
Application specific asynchronous microengines for efficient high-level control
technical reportDespite the growing interest in asynchronous circuits programmable asynchronous controllers based on the idea of microprogramming have not been actively pursued Since programmable control is widely used in many commercial ASICs to allow late correction of design errors to easily upgrade product families to meet the time to market and even efficient run time modications to control in adaptive systems we consider it crucial that self timed techniques support efficient programmable control This is especially true given that asynchronous (self-timed) circuits are well suited for realizing reactive and control intensive designs We offer a practical solution to programmable asynchronous control in the form of application-speciffic microprogrammed asynchronous controllers (or microengines). The features of our solution include a modular and easily extensible datapath structure support for two main styles of hand shaking (namely two phase and four phase), and many efficiency measures based on exploiting concurrency between operations and employing efficient circuit structures Our results demonstrate that the proposed microengine can yield high performance-in fact performance close to that offered by automated high level synthesis tools targeting custom hard wired burstmode machines
Application specific asynchronous microgengines for efficient high-level control
technical reportDespite the growing interest in asynchronous circuits, programmable asynchronous controllers based on the idea of microprogramming have not been actively pursued. Since programmable control is widely used in many commercial ASICs to allow late correction of design errors, to easily upgrade product families, to meet the time to market, and even effect run-time modifications to control in adaptive systems, we consider it crucial that self-timed techniques support efficient programmable control. This is especially true given that asynchronous (self-timed) circuits are well suited for realizing reactive and control-intensive designs. We offer a practical solution to programmable asynchronous control in the form of application-specific micro-programmed asynchronous controllers (or microengines). The features of our solution include a modular and easily extensible datapath structure, support for two main styles of handshaking (namely two-phase and four-phase), and many efficiency measures based on exploiting concurrency between operations and employing efficient circuit structures. Our results demonstrate that the proposed microengine can yield high performance?in fact performance close to that offered by automated high-level synthesis tools targeting custom hard-wired burstmode machines
Image data processing system requirements study. Volume 1: Analysis
Digital image processing, image recorders, high-density digital data recorders, and data system element processing for use in an Earth Resources Survey image data processing system are studied. Loading to various ERS systems is also estimated by simulation
Evaluation of the PlayStation 2 as a cluster computing node
Cluster computing is currently a popular, cost-effective solution to the increasing computational demands of many applications in scientific computing and image processing. A cluster computer is comprised of several networked computers known as nodes. Since the goal of cluster computing is to provide a cost-effective means to processing computationally demanding applications, nodes that can be obtained at a low price with minimal performance tradeoff are always attractive. Presently, the most common cluster computers are comprised of networks of workstations constructed from commodity components. Recent trends have shown that computers being developed and deployed for purposes other than traditional personal computers or workstations have presented new candidates for cluster computing nodes. The new computing node candidates being considered may provide a competitive and even less expensive alternative to the cluster computing nodes being used today. Machines such as video game consoles, whose prices are kept extremely low due to intense marketplace competition, are a prime example of such machines. The Sony PlayStation 2, in particular, provides the user with low-level hardware devices that are often found in more expensive machines. This work presents and evaluation of the PlayStation 2 video game console as a cluster computing node for scientific and image processing applications. From this evaluation, a determination is made as to whether the PlayStation 2 is a viable alternative to the cluster computing nodes being used today
Multiprocessor/Multicomputer Systems and Optimal Loading Techniques
This report reviews the subject of multiprocessor/multicomputer systems and optimal loading techniques. This report covers: 1. The interrelationship of Multiprocessor/Multicomputer (Multiple Instruction Stream Multiple Data Stream, MIMD) systems and other architectures by presenting a categorization of computer architectures. 2. Comparison of Multiprocessor/Multicomputer (MIMD), versus Parallel Processor (Single Instruction stream Multiple Data stream, SIMD) systems. 3. Multiprocessor/Multicomputer problems, pitfalls and new goals. 4. Investigation of loading techniques by reviewing particular MIMD executive designs
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