A Small-Scale Distributed Microprocessor System Using Shared Memory Technique

A simple technique for arranging interprocessor communication through a shared random access memory (RAM) in a small-scale distributed microprocessor system is presented. An arbiter which employs a simple hardware and requires no external clock is proposed. The arbiter consists of a controller and a scanner. The controller receives a shared memory request from a microprocessor and sends a GRANT or WAIT signal back to the microprocessor according to a command from the scanner. The scanner schedules the shared memory accessing for each microprocessor. The technique can be used for interprocessor communication at a rate of less than 87 kbytes/s with 4 Z-80 microprocessors working at a 2-MHz clock signal. The microprocessors in the system need not be identical, but are required to have a WAIT state and a FETCH state indicator. The system can be increased up to 6 microprocessors and is good for a small-to-medium scale real-time control application. A front-end communication system using the proposed system is also presented as an application.     

基于ARM单片机的小车显示系统设计

为完成小车显示系统的设计方案,根据LM3S811微处理器和TH12864液晶显示模块的主要功能及特点,设计出了小车显示系统的软硬件实现方法,经过实际系统的测试和验证,驱动程序功能正常,可供参考,且LM3S811硬件资源丰富,软件易于编程开发,开发的显示系统可方便移植应用到其他领域。     

Microprocessor implementation of a state feedback control strategyfor a current source inverter-fed induction motor drive

The realization of a microprocessor-based controller which implements a complete state-feedback control strategy for a current source inverter-fed induction motor drive is reported. The controller design is based on the application of the pole assignment technique of multivariable system regulation theory to a d,q-axis state-space linearized model of the drive and includes a reduced-order observer to achieve fast regulation and stability. The observer is designed to reconstruct the inaccessible states such as d,q -axis rotor current from a knowledge of the system inputs and outputs. The hardware and software implementation of the controller around an 8085-based microprocessor kit is discussed, and typical test results are presented, along with digital simulation results, to show its performance     

On the notion of control signals in digital designs

The concept of control signals is fundamental to digital design. It evokes the notion of one or more signals that influence computation on other signals in a system, and regulate the behavior of the system. A formal definition of control signals is presented. It is argued that knowledge of the control signals in a complex design such as a microprocessor or a computer is crucial to the comprehension and specification of the design and that knowledge of the control signals of a design leads to a more efficient hardware implementation. The identification of control signals in two microprocessors are presented as examples     

Microprocessor Control of Cycloconverter: Techniques for Implementation and Testing

Since the 1930's, cycloconverter control circuits have been designed with vacuum tubes, transistors, and integrated circuits. With the advent of microprocessors, much more logical and computational power became available in much less space and cost. This led to the design of converter control circuits using microprocessors [2]-[9]. Each of these papers describes a specific implementation. Advancements in microprocessor technology are still going at full steam. To take full advantage of this technology and its continued advancements, a systematic and broad-based study of techniques that can be used for cycloconverter control-on microprocessor-based systems-is required. This paper reports the findings of such a study [10]. In this study a few general techniques were developed for cycloconverter control. In developing the various Techniques, accuracy of trigger timing and the system's speed of response were used as performance criteria. The techniques developed were tested on a system based on the 8085 CPU. Each technique was tested qualitatively by recording the cycloconverter waveforms produced by using it. For quantitative testing, first, the theoretical trigger timings were found by a digital computer simulation of the cycloconverter. These timings were then compared with those produced on the microprocessor-based system. From the test results it was concluded that an 8 bit data width suffices for cycloconverter control. The main bottleneck in achieving the desired performance is the execution time of the processor. In one of the techniques, when improvement in trigger timing accuracy was achieved it lead to reduction in the speed of response.     

Microprocessor-based digital system design fundamentals and the development laboratory for hardware designers and engineering executives

This paper reviews the fundamentals of the basic digital computer sufficient enough for the hardware engineers and engineering executives to deal with microprocessors as components in digital system design. Two examples are used as a vehicle to guide the readers who are presumingly accustomed to thinking in hardware terms towards thinking in software. An algorithm utilizing state-minimization concepts to implement sequential logic by a set of mnemonic instructions is introduced. A brief view of microcomputer software is then presented as an attempt to arouse the designer's awareness of application, system, and development-aid softwares. Next, economic considerations are presented for overall decision making. Finally, a minicomputer-driven microprocessor laboratory oriented to both teaching and system development purposes is described. For completeness as well as for a comparison of the logic realization by INSTRUCTIONS with that implementation of logic by hardwire logic, ROM, and PLA, the latter age included in Appendices I and II. An extensive bibliography is provided for interested readers who wish to persue this topic further.     

Microprocessor-based sliding mode controller for a micromachine

The design and microprocessor-based implementation of a power system stabilizer using variable-structure systems theory is presented. The design is based on a geometric approach for finding the switching hyperplanes for discontinuous control. The stabilizer is implemented on a laboratory micromachine using an INTEL 8085A microprocessor. The experimental results show the effectiveness of the stabilizer in improving system damping. The parameter insensitivity in the sliding mode is demonstrated     

针对Motorola微处理器的BDM调试系统的设计

BDM调试模式全称背景调试模式(Background Debugger Mode)。在Motorola的PowerPC5xx／8xx，ColdFire系列微处理器中，都集成有这种调试模块。本文将详细的介绍BDM调试方式的特点，并在基础上针对ColdFire系列处理器MCF5272讨论了BDM调试系统的软硬件设计方法。     

First Silicon Functional Validation and Debug of Multicore Microprocessors

Microprocessor designs are increasingly moving towards multiple cores on a single die. Validating memory consistency, coherency, ordering, and atomicity is crucial. X86 microprocessors are prevalent at most levels of computing. Thus, new x86 microprocessors undergo extensive compatibility testing. Being a high volume product, the economic and logistical repercussions of a functional deficiency escaping into the production cycle and beyond are humbling. The first silicon functional validation and debug of multicore microprocessors are constrained by design complexity, compatibility with existing hardware and software, and time-to-market pressures. This paper describes microprocessor debug features and their use in debugging functional failures. An encompassing overview of the microprocessor's first silicon validation is presented. Emphasis is put on validation and debug of multicore microprocessors targeting multinode systems. This paper presents a novel method to validate and debug intra-node and inter-node communication traffic. This paper also develops an analysis to determine optimal on die debug resources. Finally, data from an 8-node system is presented to demonstrate the extent of intrusiveness of a coherent and noncoherent traffic debug feature     

A Brushless DC Motor Controlled by a Microprocessor with Examples for a Three-Phase Motor

The principle and the characteristics of a brushless dc motor and a driver circuit using bipolar transistors are described briefly. Motor control by microprocessor, including hardware and software commutation, speed measurement, and control via software algorithms, is described in more detail. Different current choppers were investigated: the hysteresis current chopper, the fixed-frequency current chopper, and the software current chopper (Patent EP 0 093 182 A1, US 4 514 667). Application examples and implementation details for the print-band drive of an impact printer are discussed. Finally, microprocessors are ideal devices to detect, to isolate, and to pass on errors for display.     

基于微处理器的SAR成像处理转置存储

针对合成孔径雷达(SAR)实时成像处理系统对大容量多模式转置存储器的需求，探讨了基于微处理控制器的实现方案，并对研制的基于DSP控制的转置存储器进行了详细的分析。可以看出，DSP控制的转置存储器因有软硬件结合的工作方式，使其具有高度的灵活性和扩展性。     

Interrupt-driven microprocessor-based overcurrent relay

An interrupt-driven overcurrent relay for power systems using the 8085 microprocessor is presented. The relay requests processing time from the microprocessor only when a fault occurs. In this way, the microprocessor is given the opportunity to run other tasks such as diagnostic tests online during normal conditions     

A 4800 Bit/s Microprocessor Data Modem

The development of a new 4800 bit/s data modem, based on real-time digital signal processing by program controlled microprocessors, is described. The modem is fully compatible with the CCITT Recommendations V.27 bis and V.27 ter. In the microprocessor modem, all the digital signals are processed by one general purpose microprocessor unit only and no hardware multiplier is employed. A series of processing cycle reduction tactics have allowed an off-the-shelf microprocessor to handle all the modem functions in a real-time environment. Particularly noteworthy, among these tactics, is the use of a decision feedback equalization algorithm. Numbers of multiplications, which are required for a conventional linear equalization, are shown to be obviated with the DFE algorithm. It is also shown that the DFE facilitates a certain timing phase control method. The microprocessor modem is extremely flexible because of its software controlled nature, and through programming it will provide a variety of additional functions.     

A Microprocessor-Based Multiloop Process Controller

This paper describes a microprocessor-based multiloop process controller which can be readily utilized in a broad range of industrial applications. The controller, developed around Intel's 8085 microprocessor, provides the user with, in one unit, a software package combining feedback, feed-forward, ratio, and cascade control functions.     

嵌入式实时操作系统pSOS在多媒体通信终端中的应用

在多媒体通信终端的基本实现方案中,通常有基于PC平台的终端和基于媒体处理器的独立机型终端两种。在后一种方案中,硬件系统的资源管理和应用软件的开发都是基于嵌入式实时操作系统来实现的。Philips公司的TriMedia媒体处理器,介绍嵌入式实时操作系统pSOS在H．324多媒体通信终端中的应用。     

Microprocessors in a digital system design curriculum

For some time now, the notion that "an algorithm is an algorithm" has been emphasized in digital system design. In approaching such design problems, the question of hardware versus software implementation of the algorithm should be left to the last. In fact, such approaches have not been viable until the advent of the microprocessor, and software design has seemingly gone its own way independently of hardware design. But has it really? It is becoming increasingly clear that structured approaches to the design of digital systems, hardware or software, have evolved in both areas and are virtually identical. It is possible to teach a course on digital system design so that a diverse group can understand and learn from each other's background. It is also possible to have a laboratory wherein realistic projects can be undertaken. In this paper, the digital system design sequence and laboratory facilities at Northwestern University will be discussed. Also, desirable design tools will be postulated.     

MMV: A Metamodeling Based Microprocessor Validation Environment

With increasing levels of integration of multiple processing cores and new features to support software functionality, recent generations of microprocessors face difficult validation challenges. The systematic validation approach starts with defining the correct behaviors of the hardware and software components and their interactions. This requires new modeling paradigms that support multiple levels of abstraction. Mutual consistency of models at adjacent levels of abstraction is crucial for manual refinement of models from the full chip level to production register transfer level, which is likely to remain the dominant design methodology of complex microprocessors in the near future. In this paper, we present microprocessor modeling and validation environment (MMV), a validation environment based on metamodeling, that can be used to create models at various abstraction levels and to generate most of the important validation collaterals, viz., simulators, checkers, coverage, and test generation tools. We illustrate the functionalities in MMV by modeling a 32-bit reduced instruction set computer processor at the system, instruction set architecture, and microarchitecture levels. We show by examples how consistency across levels is enforced during modeling and also how to generate constraints for automatic test generation.     

基于MCGS系统的DCS总线接口的设计与实现

MCGS系统需要控制和处理多种现场设备.介绍一种新型的DCS总线接口设备的硬、软件的设计与实现过程,该设备能够使MCGS组态软件接入DCS总线成为控制系统,实现信息采集、传输和控制功能.该接口设备使用LPC2136作为微处理器,面向的DCS系统使用RS 485线路作为通信、驱动总线.该总线接口在数据实时采集和监控中可以取得较好的控制效果.     

Automatic unit delay execution circuit for digital signalprocessing systems based on general-purpose microprocessors

A simple circuit is proposed for automatic unit delay execution during the implementation of digital filters on general purpose microprocessors. The hardware overhead of the circuit is negligible, independent of the filter order and of the number of microprocessors (in the case of multimicroprocessor systems). The software overhead is zero     

Microcomputer-based single-phase to three-phase cycloconverter

A microprocessor application for a single-phase to three-phase cycloconverter is presented. An algorithm is formulated for the cosine-wave modulation method so that it requires only one reference wave (RW) to generate the trigger pulses for all three phases. The method is implemented on an 8085 microprocessor system with output frequencies that are integer submultiples of the input frequency. The operating principle of the cycloconverter is reviewed. A complete software design of the scheme is given, and test results are presented for an induction motor load. The difference between the experimental and the calculated values of the firing angle is in the range of 0 to 0.51° for the selected step size of 1°. This can be reduced further by reducing the step size from 1° to some lower value. Output voltage and current waveforms for an induction motor load approach sinusoidal