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

13.4 Bottom-Up (Results-Driven) Performance Modeling

Bottom-up modeling is based on using known data to predict system performance. To illustrate this approach, consider the small control system shown in Figure 13.13:

Figure 13.13: Example system 1 – marine gas turbine power loop controller

Over time, performance data has been collected on individual computing functions, such as the control algorithms. Using information like this makes it possible to predict the total control program timing, as shown in Figure 13.14. This technique can be used effectively in small systems or in subsystems of larger applications. However, the technique is not as foolproof as it may seem; the times actually produced in new designs depend on many factors, including:

  • Processor type
  • Clock rate
  • Memory speeds and use of memory caches
  • Location of code in memory
  • Compiler efficiency
  • Compiler optimization techniques:

Figure...