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

13.2 Performance Engineering – Requirements, Targets, and Achievables

Here, performance requirements are taken to mean desired or specified performance objectives, as in Figure 13.4:

Figure 13.4: Performance requirements and achievables

The highest-level specifications, project performance requirements, are generated by the needs of the system itself. These, together with functional and other requirements, act as inputs to the system design activity. In developing system architectures to meet these needs, designers (even at this early stage) usually try to define what actually can be achieved. Take, for example, where the architectural model consists of two computers linked by a dedicated serial data link. Assume that the following items have been decided on:

  • Link protocol: HDLC
  • Transmission rate: 1 Megabit/sec
  • Message length (minimum): 32 bytes
  • Protocol overhead: 6 bytes

Elementary calculations show that it will take at least...