Computer Architecture

5

DIGITAL LOGIC

Switches such as the semiconductor transistors seen in the previous chapter are the most basic building block of modern electronic computation. But architects don’t usually think in terms of switches. Instead, they build up a hierarchy of more complex structures from them, eventually forming a CPU. The next layer of this hierarchy consists of logic gates: devices formed from a few switches in standard circuits representing basic Boolean functions, such as AND and OR. Logic gates, in turn, can be used to build up larger structures such as simple machines for arithmetic and memory.

In this chapter, we’ll examine some common types ...