Specification of Reactive Hardware/Software Systems - Electronic ...

Chapter 1
Introduction
1.1 Objectives
This thesis describes research towards the development of a specification and design
method for complex reactive distributed systems that must be realised in hardware
and/or software. Examples of such systems are tele/data communication networks and
switches, industrial control systems, as well as many modern consumer products. These
systems are often implemented as a collection of communicating processors combined
with ASICs and complex software.
The objective of this thesis is to develop a method as well as the base for future development
of methods in general. The method is a contribution to solve contemporary
specification problems in the practice of business. We selected the research areas of structured
analysis, object-oriented analysis, formal behaviour description and behaviourpreserving
structure transformation as main topics.
An adequate specification process transforms a vague product idea into an ’implementable’
description. This process has necessarily an informal input side and an output
that should be as formal as possible. This leads to conflicting objectives for a specification
method. On the one hand a method must preferably use informal languages for
communication with users and various experts from marketing to service. On the other
hand a method must produce a description that can be processed by computer tools,
such as simulators, and (silicon) compilers.
A specification and design method should have a formal base and deliver executable
models of the system to be designed. Executable models can be used for verification
and validation of system properties. Execution requires that the behaviour description
can be interpreted unambiguously. A formal behaviour specification language based
on a formal operational semantic model is therefore a premise. The development of a
semantic model is far from trivial. The research area of formal semantics is relatively
new, which made this part of our research challenging.
Object-orientation typically has been a research topic in the software community. Objectoriented
analysis with a focus on hardware as well as on software is hardly explored.
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