Programming Embedded Systems in C and C++

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Chapter 1

In this chapter:

• What Is an

Embedded System?

• Variations on the

Theme

• C: The Least Common

Denominator

• A Few Words About

Hardware

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1. Introduction

I think there is a world market for maybe five computers.

—Thomas Watson, Chairman of IBM, 1943

There is no reason anyone would want a computer in their home.

—Ken Olson, President of Digital Equipment Corporation, 1977

One of the more surprising developments of the last few decades has been the

ascendance of computers to a position of prevalence in human affairs. Today there

are more computers in our homes and offices than there are people who live and

work in them. Yet many of these computers are not recognized as such by their

users. In this chapter, I’ll explain what embedded systems are and where they are

found. I will also introduce the subject of embedded programming, explain why I

have selected C and C++ as the languages for this book, and describe the hard-

ware used in the examples.

What Is an Embedded System?

An embedded system is a combination of computer hardware and software, and

perhaps additional mechanical or other parts, designed to perform a specific func-

tion. A good example is the microwave oven. Almost every household has one,

and tens of millions of them are used every day, but very few people realize that a

processor and software are involved in the preparation of their lunch or dinner.

This is in direct contrast to the ...