10.1 Introduction

All but the simplest electronic instruments have some form of embedded computer system. Given this, it is important in a handbook on electronic instruments to provide some foundation on embedded computers. The goals of this chapter ^[1] are to describe:

• What embedded computers are.

• How embedded computers work.

• The applications for embedded computers in instruments.

The embedded computer is exactly what the name implies: a computer put into (i.e., embedded) in a device. The goal of the device is not to be a general-purpose computer, but to provide some other function. In the focus of this chapter and book, the devices written about are instruments. Embedded computers are almost always built from microprocessors or microcontrollers. Microprocessors are the physical hardware integrated circuits (ICs) that form the central processing unit (CPU) of the computer. In the beginning, microprocessors were miniature, simplified versions of larger computer systems. Because they were smaller versions of their larger relatives, they were dubbed microprocessors. Microcontrollers are a single IC with the CPU and the additional circuitry and memory to make an entire embedded computer.

In the context of this chapter, embedded computer refers to the full, embedded computer system used within an instrument. Microprocessor and micro-controller refer to the IC hardware (i.e., the chip).

10.2 Embedded Computers