Digital Circuit Design

We consider the problem of designing a kind of digital circuit known as a combinational logic block. In such a circuit, the basic building block is a gate: a circuit that implements some simple boolean function. A gate could be for example an inverter, which performs logical inversion, or a more complicated function such as a “not-AND”, or NAND, which takes two boolean inputs A, B to produce the inversion of (A and B).

The basic idea is to design (size) the gates in such a way that the circuit operates fast, yet occupies a small area. There are other factors, such as power, involved in the design problem but we will not discuss this here.