P-notation: High level description language for software design

Top-down design of assembly language programs by the process of stepwise refinement is discussed and describes how modularization can be improved by the use of procedures and modules. The definition of procedures and modules in P-notation is presented and their implementation in assembly language given.     

P-notation: High level description language for software design

The previous three parts of this series have outlined a notation for designing assembly language programs. In this final article the use of the notation is illustrated by designing a fairly large program by the process of stepwise refinement. Emphasis is placed on developing a modular structure by using the procedure and module constructs in order to simplify the design process and to facilitate testing.     

P-notation: High level discription language for software design

A set of rules and guidelines for the translation of P-notation into Intel 8085 assembly language is given. Rules for translating type specifications and data declarations using assembly language directives are included. The article concludes by describing in detail the translation of the program example given in the first article of this series.     

A high level language based system for cross-assembler definition

A method to develop cross-assemblers is explained by describing the XMETA system, where the advantages given by the semantic power of meta-assemblies have been combined with the clarity of modern high level languages, such as Pascal, in defining assembly semantics. XMETA accepts a superset of the IEEE-P694 microprocessor assembly language standard syntax: system structure is detailed and examples are provided to illustrate its use. Actual experiences are briefly summarized in the conclusions.     

MAPS: a language for multi-agent system design

Abstract: A language for multi-agent system design (MAPS) is presented and discussed in this paper. Any agent in MAPS is thought of as an expert system standing on its own. It can communicate through synchronous and asynchronous message sending. Dedicated behaviours are provided which specify how incoming messages are processed. Inter-agent cooperation is controlled via production rules. Two pre-defined agent classes are provided, which are given specific problem-solving roles: Knowledge Server (KS) agents are meant to maintain and transmit knowledge about problem-solving states, while Knowledge Processor (KP) agents are meant to process these elements in order to progress towards a solution. The duality between agent and resource modelling levels on the one hand and between KS and KP modelling styles on the other is shown to allow the specification of various control strategies. The environment is currently running on HP, SUN and DEC workstations.     

Using a programming language for digital system design

HDLs must satisfy important semantic requirements, especially when CAD tools are involved. Designers can meet these requirements by using the standard language constructs of a software-programming language to model hardware for simulation and synthesis     

A GALS Infrastructure for a Massively Parallel Multiprocessor

This case study focuses on a massively parallel multiprocessor for real-time simulation of billions of neurons. Every node of the design comprises 20 ARM9 cores, a memory interface, a multicast router, and two NoC structures for communicating between internal cores and the environment. The NoCs are asynchronous; the cores and RAM interfaces are synchronous. This GALS approach decouples clocking concerns for different parts of the die, leading to greater power efficiency.     

Dataflow Architectures for GALS

In Kahn process network (KPN), the processes (nodes) communicate by unbounded unidirectional FIFO channels (arcs), with the property of non-blocking writes and blocking reads on the channels. KPN provides a semantic model of computation, where a computation can be expressed as a set of asynchronously communicating processes. However, the unbounded FIFO based asynchrony is not realizable in practice and hence requires refinement in real hardware. In this work, we start with KPN as the model of computation for GALS, and discuss how different GALS architectures can be realized. We borrow some ideas from existing dataflow architectures for our GALS designs.     

A design language and the use of cleanroom methodology for knowledge-based system development

In an effort to improve the quality of knowledge-based systems, use of the Cleanroom Software Engineering Methodology was explored. the methodology emphasizes the use of stepwise refinement techniques and proofs of correctness to prevent errors early in the development process. This calls for the use of a well-defined design language and verification techniques to prove the correctness of the design. But practical design languages and verification methods for knowledge-based systems are not well understood. This article discusses a design language, associated verification techniques, and experience with their use in developing a knowledge-based system. the language is an extension of procedural design languages with representations for control and opportunistic knowledge, emphasizing typical knowledge-based programming ideas and ease of verification. It is intended for use with a stepwise refinement process that iteratively develops detailed designs from high-level specifications. the extensive use of structured English language specifications throughout the process makes the approach practical but limits the ability to verify designs using automated tools. the design language and associated processes were used in the development of a prototype flight replanner for future air traffic control systems—a large and complex application of knowledge-based technology. © 1994 John Wiley & Sons, Inc.     

Very high-level language design: A viewpoint

Recent developments in very high-level language design indicate that these languages hold great promise for improving the level of man-machine communication, and hence improving computer and programmer utilization. (Essentially, a very high-level language one which allows the programmer to specify what to do, rather than how to do it.) This paper surveys these developments, outlines the goals to which an “ideal” very high-level language should aspire, and then presents the design of a very high-level language that would meet these goals. This design is presented in the interest of laying bare some basic design and implementation questions that are inherent to such an achievement. The paper then discusses these questions, indicating both old and new research problems which they suggest.     

An interactive language for computer-aided identification and control system design

A new interactive command language was developed to implement integrated computer-aided design in computer control applications. It is intended to operate at the supervisory level in a real-time hierarchical system.The integrated approach is based on convolution algebra and provides a unified conceptual framework for studying the behaviour of practical systems in the time domain. Consequently, as an alternative to choosing fixed system structures and design procedures, the user may evaluate experimental procedures suggested by the underlying theory.The language has been implemented on a minicomputer at Bradford University and applied to industrial control problems. The highly flexible and practical aspects of the language are demonstrated.     

BPL: A set-based language for distributed system prototyping

Rapid prototyping of software and hardware is recognized as a very important step in timely, cost-effective system development. The complexity inherent in designing distributed computing systems and distributed problem solutions emphasizes the need for effective rapid prototyping tools. ADL/ADS is a testbed user interface tool for experimentation with critical research and design issues pertaining to distributed data processing (DDP). The experimenter expresses a candidate distributed system in terms of experiment objects, along with attributes and relationships. The experiment objects represent hardware, software, and behavior. This paper provides a brief overview of ADL/ADS, and gives especial emphasis to the Behavior Prototyping Language (BPL) within ADL/ADS. BPL is designed for expressing Behavior Modules (B_MODULEs)—the most versatile of the behavior objects. BPL incorporates set-theoretical approaches, and provides syntax designed for effectively describing manipulations of experiment objects, and their attributes and relationships.     

A portable language for system development

The design and implementation of a system development language which is economical to implement is described. Both macro processing and compiling techniques are used to translate it. The advantages and disadvantages of using such a language are discussed together with the main problems met in its implementation.     

A natural language interpreter for plate girder design

One of the major problems in developing computeraided design software is the establishment of effective man-machine communication. This paper describes a computer-aided plate girder design software package and its man-machine interface using natural language processing techniques. The natural language interpreter takes advantage of the user's communication and technical skills and accepts commands in the user's native language. The user can verify the correct interpretation of the commands from the responsive graphic display of the design.