Digital Hardware Systems Research Articles

Verischemelog

Verischemelog (pronounced with 5 syllables, veruh-scheme-uh-log) is a language and programming environment embedded in Scheme for designing digital electronic hardware systems and for controlling the simulation of these circuits. Simulation is performed by a separate program, often a commercial product. Verischemelog compiles to Verilog, an industry standard language accepted by several commercial and public domain simulators. Because many design elements are easily parameterized, design engineers currently write scripts which generate hardware description code in Verilog. These scripts work by textual substitution, and are typically ad-hoc and quite limited. Preprocessors for Verilog, on the other hand, are hampered by their macro-expansion languages, which support few data types and lack procedures. Verischemelog obviates the need for scripts and preprocessors by providing a hardware description language with list-based syntax, and Scheme to manipulate it. An interactive development environment gives early and specific feedback about errors, and structured access to the compiler and run-time environment provide a high degree of reconfigurability and extensibility of Verischemelog.

Experimental investigation of subcooled liquid nitrogen impingement cooling of a silicon chip : David T. Vader, Gregory M. Chrysler, Richard C. Chu and Robert E. Simons. IEEE Transactions on Components, Packaging and Manufacturing Technology—Part A, 18 (4), 788 (1995)

Several embedded system applications are used to control physical processes thus leading to the concept of Cyber-Physical System. Sensing, computation and actuation are combined by involving a set of highly heterogeneous components, i.e., digital and analog hardware, software, energy sources, and external physical systems (e.g., a room to be heated, a mechanical component). Moreover, we see the growing use of networks to connect several sub-systems in a more efficient way; this contributes to introduce a further level of heterogeneity due to the presence of messages exchanged over communication channels. All these aspects should be taken into account in the design process to find highly optimized solutions; in particular, simulation is a key technique for their verification. However, the heterogeneity of components, together with the presence of the network, forces to adopt complex and slow co-simulation techniques to carry on the simulation of the entire system.This work aims at proposing SystemC as unified framework to model and simulate Networked Cyber-Physical Systems. Concerning the modeling of continuous-time components and a specific class of discrete-time components, the different Models of Computation provided by the Analog/Mixed-Signal (AMS) extension of SystemC are used. Regarding the network, SystemC and the SystemC Network Simulation Library are used to model communications at different abstraction levels. The approach is validated by considering a networked control system. First, the accuracy and speed of SystemC simulation is compared to Matlab/Simulink simulation. Second, different simulation alternatives are compared to co-simulation. Finally, we show that the simulation speed-up achieved by all-SystemC modeling allows to explore several design alternatives and the accurate modeling of the communication network can improve the design of the controller.

Current monitoring technique for testing embedded analogue functions in mixed signal ICs

The authors demonstrate how M-sequences and current monitoring can be combined to produce a system level technique for testing analogue circuits, much of the test hardware being obtained from reconfigured digital system hardware.

Application of predictive control algorithm in speed control system

In view of DC speed control system, this paper presents a predictive control algorithm to replace traditional PID control. System predictive model requires little information of the controlled object, and because it adopts rolling optimum method, system possesses excellent dynamic and static performance. According to the practice results, it owns outstanding speed regulating and tracking property. Full digital system hardware improves system reliablity and it is easy to be adjusted. To reduce CPU’s complex calculation, we have studied and developed a digital hardware trigger. The trigger’s identical waveform and steady trigger pulse greatly facilitates system design work and improves system’s overall quality of antidisturbance. This device surely owns a prosperous prospect.

Specification and design of concurrent control units

Complex digital hardware systems are usually partitioned into processing units and control units. While conventional CAD-systems support design engineers in developing the processing units, the main problems lie in designing the architecture of associated controllers. There is a lack of systematic design concepts, particularly for such types of control tasks that must be distributed among several cooperating control units. To solve these problems we have developed an integrated design concept which supports the specification and implementation of cooperating control units. We introduce our novel concurrent controller specification language COCOS which is especially defined to describe control units and their interaction in a modular and implementation independent form. Also, we present the top-down transformations to map control task specifications to nets of cooperating finite state machines.

Producing "Kombination XI:" Using Modern Hardware and Software Systems for Composition

The author discusses two topics related to the realization of his composition Kombination XI: A Ritual Place for Live and Processed Voices . The first is his development of a notation system and a set of software tools based on weighted trees that span the expressive and structural domains of music. The second is his process of realization, in which several different digital signal-processing software and hardware systems were used in consort as one instrument.

A microcomputer-controlled system for use in auditory physiology

This report describes a digitally controlled system for use in auditory physiology in which signal generation and data acquisition are under the control of a single microcomputer. The system is designed to generate the complex waveforms required in neuroethological studies, and is able to generate these signals at frequencies of up to 160 kHz with a resolution of 1 Hz. The system is built around a commercially available digital hardware system, and augmented with custom components to enhance operation speed, precision and flexibility.

Computer relaying and expert systems: New tools for detecting high impedance faults

It has long been known that certain types of faults and unacceptable operating conditions on electric distribution feeders cannot be detected by using conventional protection practices. However, advanced digital system hardware and software methods are being used to develop new techniques for protection and on-line diagnosis of system operations. This paper presents newly developed methods for the detection of high impedance, low current faults using signal processing and pattern recognition techniques in computer relaying architecture with expert systems. The characteristics of these faults are described, including the analytical methods used to separate detection parameters from the overall frequency spectrum generated by the fault transients. Fault detection parameters are identified and algorithms suitable for computer relays are presented. Elements of a digital system architecture required to implement protection algorithms are discussed. Expert system methods used in the implementation of the protection and diagnosis software are also described.

A Restructurable Integrated Circuit for Implementing Programmable Digital Systems

The Restructurable Integrated Circuit, a highly flexible and programmable multimicrocomputer is presented. The goal of this integrated circuit is to apply the large number of gates that are available on a custom designed VLSI IC to the design of a highly flexible integrated circuit . The main application of the Restructurable Integrated Circuit (RIC) will be the implementation of digital system hardware through programmation of a RIC. The flexibility provided within the RIC includes: user definable micro language, user programmable assembly language, user programmable microcode, dynamic coordination of multiple internal processors, coordination of processors on multiple RICs, internal memory use as caches or as a member of a virtual memory hierarchy, qeneral topology for interchip communication and external data paths, and a user definable interrupt mechanism. By providing this high degree of flexibility, the cost and reliability advantages of high volume production can be accrued, while providing performance comparable to a custom VLSI IC.

A fast digital Walsh-Hadamard signal processing system

A fast digital hardware system for signal analysis and synthesis is presented. This system, combined with data compression or information rate reduction techniques, which are also discussed in the paper, provides a powerful tool for a variety of control, communication and signal processing applications. An illustrative example is given.

Fast Monte Carlo Integration of PDF Estimators

Abstract The problem of integrating an estimate of the probability density function in a high-dimensional measurement space arises when we attempt to classify incomplete vectors of the form (3.7, ?, —2.54, ?, 19.6) (? denotes an unknown value). While Monte Carlo methods are, in theory, applicable to this and any other integration problems, they are notoriously slow and hence were disregarded, in an earlier paper, as impractical. In this paper, this conclusion is questioned. There are many ways in which the integration can be made faster. This is possible by reformulating the problem and thereby eliminating all unnecessary calculations from within the iterative loop. In addition, fast analog and digital hardware systems could be built to implement this iteration process. This paper is tentative; it is still too early to decide whether these savings will be sufficient to yield a really effective practical method.

Structure of digital system description languages

Several languages have been developed for or applied to the problem of describing digital hardware systems. This paper points out some of the problems encountered in hardware descriptions, particularly where they are distinct from concepts appearing in programming languages.