Semiconductor Basics

14Microprocessors and Modern Electronics

OBJECTIVES OF THIS CHAPTER

In Chapters 11 and 12 we looked at a number of semiconductor circuits that accomplish a specific function. Now we are ready to put many of these components together and look at how computers work. As I have tried to do throughout this book I will, as much as possible, go inside the computer and look at the relation of its inner working with what we have learned about semiconductors and semiconductor devices.

I will also cover liquid crystal displays, which are found everywhere, and show that although the media is the liquid cells, how they operate is based also on semiconductor technology.

14.1 The Computer

14.1.1 Computer Architecture

In Figure 14.1 I show the basic components of a modern computer. You'll find that different books show different computer architectures. It depends very much on how many details one wants to include and how the different functions are combined. For example, the central processing unit (CPU) includes the control, the arithmetic unit, and the registers. Figure 14.1 is just one simple way of showing all the major components. It also shows the interconnections between these large boxes. Some of the interconnections are just data that we want to move from one place to another and some are instructions (darker lines) that tell the CPU what to do.

In Section 12.5 we covered, in quite a bit of detail, memories. The memories box in Figure 14.1 includes the long‐term memory as ...