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

5.1 The Task Model of Software

5.1.1 Modeling – What and Why

This opening section might, at first, seem to be somewhat academic, far removed from the reality of software and software engineering. Not so. It does, in fact, deal with a very practical and important topic: the use of models as part of the design process. However, before going further, we need to answer two key questions:

  1. What is a model?
  2. Why do we use models?

A model, in our view, is a "representation of reality." Although that sounds pretty abstract (and not especially helpful), it actually gets to the heart of the matter. Now, let's make it more meaningful by looking at some tangible items (Figures 5.1, 5.2, and 5.3):

Figure 5.1: Clay model of a car

Figure 5.2: Functional scale model of a marine craft

Figure 5.3: Block diagram model of a microcomputer

In the auto industry, it is common practice to produce...