244 research outputs found

    User microprogrammable processors for high data rate telemetry preprocessing

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    The use of microprogrammable processors for the preprocessing of high data rate satellite telemetry is investigated. The following topics are discussed along with supporting studies: (1) evaluation of commercial microprogrammable minicomputers for telemetry preprocessing tasks; (2) microinstruction sets for telemetry preprocessing; and (3) the use of multiple minicomputers to achieve high data processing. The simulation of small microprogrammed processors is discussed along with examples of microprogrammed processors

    A higher-order language for describing microprogrammed computers

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    Sequential language for describing microprogram controlled computer

    Automatic synthesis of application-specific processors

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    Thesis (D. Tech. (Engineering: Electrical)) -- Central University of technology, Free State, 2012This thesis describes a method for the automatic generation of appli- cation speci_c processors. The thesis was organized into three sepa- rate but interrelated studies, which together provide: a justi_cation for the method used, a theory that supports the method, and a soft- ware application that realizes the method. The _rst study looked at how modern day microprocessors utilize their hardware resources and it proposed a metric, called core density, for measuring the utilization rate. The core density is a function of the microprocessor's instruction set and the application scheduled to run on that microprocessor. This study concluded that modern day microprocessors use their resources very ine_ciently and proposed the use of subset processors to exe- cute the same applications more e_ciently. The second study sought to provide a theoretical framework for the use of subset processors by developing a generic formal model of computer architecture. To demonstrate the model's versatility, it was used to describe a number of computer architecture components and entire computing systems. The third study describes the development of a set of software tools that enable the automatic generation of application speci_c proces- sors. The FiT toolkit automatically generates a unique Hardware Description Language (HDL) description of a processor based on an application binary _le and a parameterizable template of a generic mi- croprocessor. Area-optimized and performance-optimized custom soft processors were generated using the FiT toolkit and the utilization of the hardware resources by the custom soft processors was character- ized. The FiT toolkit was combined with an ANSI C compiler and a third-party tool for programming _eld-programmable gate arrays (FPGAs) to create an unconstrained C-to-silicon compiler

    Graphical microcode simulator with a reconfigurable datapath

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    Microcode is a symbolic way to simplify control design that allows changing, testing and updating the control unit of processors. By changing the microcode, the same datapath can be used for an entirely different application, such as supporting a completely different instruction set. For these reasons, a majority of control units in modern day processors are microcoded. The object was to investigate and implement a graphical microcode simulator with a reconfigurable datapath and microcode format. By allowing a wide configuration of the datapath, many types of logical processors can be designed and simulated. The resulting implemented simulator is able to fill the void in microprogramming tools since there are no graphical microcode simulators that allow such customization of the datapath. The customization of the datapath goes beyond allowing different files specifying the datapath, it allows the datapath to be created and modified using the graphical interface.This tool is able to be used to design and simulate general-purpose processors and application specific processors through datapath and microcode configurations. In the academic setting, this tool provides easier microcode testing through verification on the instruction level for instructors and provide simulation debugging through code tracing and breakpoints for students

    A machine-independent microprogram development system

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    The aims of this project are twofold. They are firstly, to implement a microprogram development system that allows the programmer to write microcode for any microprogrammable machine, and secondly, to build a microprogrammable machine, incorporating the user friendliness of a simulator, while still providing the 'hands on' experience obtained actual hardware. Microprogram development involves a two stage process. The first step is to describe the target machine, using format descriptions and mnemonic-based template definitions. The second stage involves using the defined mnemonics to write the microcodes for the target machine. This includes an assembly phase to translate the mnemonics into the binary microinstructions. Three main components constitute the microprogrammable machine. The Arithmetic and Logic Unit (ALU) is built using chips from Advanced Micro Devices' Am29ØØ bit-slice family, the action of the Microprogram Control Unit (MCU) is simulated by software running on an IBM Personal Computer, and a section of the IBM PC's main memory acts as the Control Store (CS) for the system. The ALU is built on a prototyping card that plugs into one of the slots on the IBM PC's mother board. A hardware simulator program, that produces the effect of the ALU, has also been developed. A small assembly language has been developed using the system, to test the various functions of the system. A mini-assembler has also been written to facilitate assembly of the above language. A group of honours students at Rhodes University tested the microprogram development system. Their ideas and suggestions have been tabulated in this report and some of them have been used to enhance the system's performance. The concept of allowing 'inline' microinstructions in the macroprogram is also investigated in this report and a method of implementing this is shown

    Aerospace Applications of Microprocessors

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    An assessment of the state of microprocessor applications is presented. Current and future requirements and associated technological advances which allow effective exploitation in aerospace applications are discussed

    Application of bit-slice microprocessors to digital correlation in spread spectrum communication systems

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    This thesis describes the application of commercially available microprocessors and other VLSI devices to high-speed real-time digital correlation in spread spectrum and related communication applications. Spread spectrum communications are a wide-band secure communication system that generate a very broad spectral bandwidth signal that is therefore hard to detect in noise. They are capable of rejecting intentional or unintentional jamming, and are insensitive to the multipath and fading that affects conventional high frequency systems. The bandwidth of spread spectrum systems must be large to obtain a significant performance improvement. This means that the sequence rate must be fast and therefore very fast microprocessors will be required when they are used to perform spread spectrum correlation. Since multiplication cannot be performed efficiently by microprocessors considerable work, since 1974, has been published in the literature which is devoted to minimising the requirement of multiplications in digital correlation and other signal processing algorithms. These fast techniques are investigated and implemented using general-purpose microprocessors. The restricted-bandwidth problem in microprocessor-based digital correlator has been discussed. A new implementation is suggested which uses bit-slice devices to maintain the flexibility of microprocessor-based digital correlation without sacrificing speed. This microprocessor-based system has been found to be efficient in implementing the correlation process at the baseband in the digital domain as well as the post-correlation signal processing- demodulation, detection and tracking, especiaJIy for low rate signals. A charge coupled-device is used to obtain spectral density function. An all-digital technique which is programmable for any binary waveform and can be used for achieving initial acquisition and maintaining synchronisation in spread spectrum communications is described. Many of the practical implementation problems are discussed. The receiver performance, which is measured in terms of the acquisition time and the bit-error rate, is also presented and results are obtained which are close to those predicted in the system simulations

    A high speed special purpose processing unit for logic simulation

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    The growing complexity of integrated circuits has made simulation, through software-based simulators, very time consuming. The declining cost of hardware and a massive amount of computing time required to simulate logic networks have made the use of hardware simulators very attractive;This dissertation describes the architecture of a specialized, highly parallel, and programmable hardware accelerator for logic simulation. It is designed with commercially available chips in a microprogrammed environment. Any future changes can be accommodated by a change in microcode. High speed is achieved by exploiting parallelism, both in the logic network and the hardware of the processing unit. A standard bus is used for communication between the processing unit and the host computer. A thick , nonstandard bus is used for communication of data within the processing unit at a very high speed. By using two buses, intermediate simulation results could be sent to the host computer in parallel with the simulation of devices. Devices are simulated in a pipelined fashion. Reliability is increased by providing error detection and correction capability for memories and buses, and by providing built-in hardware for diagnostics in a computer-aided environment. Evaluation programs of new devices can be loaded in the processing unit through the host computer. Event driven simulation with arbitrary delays and signal values have been used. Devices are divided into various categories to utilize system resources efficiently. Any device, simple or functional, can be simulated
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