Book Image

The Complete Edition - Software Engineering for Real-Time Systems

By : Jim Cooling
Book Image

The Complete Edition - Software Engineering for Real-Time Systems

By: Jim Cooling

Overview of this book

From air traffic control systems to network multimedia systems, real-time systems are everywhere. The correctness of the real-time system depends on the physical instant and the logical results of the computations. This book provides an elaborate introduction to software engineering for real-time systems, including a range of activities and methods required to produce a great real-time system. The book kicks off by describing real-time systems, their applications, and their impact on software design. You will learn the concepts of software and program design, as well as the different types of programming, software errors, and software life cycles, and how a multitasking structure benefits a system design. Moving ahead, you will learn why diagrams and diagramming plays a critical role in the software development process. You will practice documenting code-related work using Unified Modeling Language (UML), and analyze and test source code in both host and target systems to understand why performance is a key design-driver in applications. Next, you will develop a design strategy to overcome critical and fault-tolerant systems, and learn the importance of documentation in system design. By the end of this book, you will have sound knowledge and skills for developing real-time embedded systems.
Table of Contents (16 chapters)
Preface
15
Glossary of terms

6.1 Diagrams – Why?

6.1.1 Introduction

Why do we use diagrams? Not 'why do we use software diagrams?', but why do we use diagrams at all? We couldn't imagine civil, mechanical, or electrical engineers working without diagrams. And, at a much simpler level, try putting together self-assembly furniture using only written instructions (no pictures).

This takes us into the area of psychology. Our experiences show us that pictures must convey information in a different way from words, and in a way that is clearer and easier to understand. T. R. G. Green [GRE82] describes this in terms of temporal processes, dealing with many aspects of the problem, including:

  • Recognition – is the process familiar?
  • Modularity – what chunks can the description be broken into?
  • Tractability – how can a modification be made?
  • Sequence – in what order do the events happen?
  • Circumstance – if such and such happens, what does...