TABLE OF CONTENTS Objective: This chapter introduces the most fundamental logic gates and also the most fundamental of all registers along with basic applications. Moreover, to make the presentations more effective and connected to the physical implementations, the corresponding electronic circuits, using CMOS architecture, are also included. Even though many other details will be seen later, the concepts selected for inclusion in this chapter are those absolutely indispensable for the proper understanding and appreciation of the next chapters.
Chapter Contents
| 4.1 | Introduction to MOS Transistors |
| 4.2 | Inverter and CMOS Logic |
| 4.3 | AND and NAND Gates |
| 4.4 | OR and NOR Gates |
| 4.5 | XOR and XNOR Gates |
| 4.6 | Modulo-2 Adder |
| 4.7 | Buffer |
| 4.8 | Tri-State Buffer |
| 4.9 | Open-Drain Buffer |
| 4.10 | D-Type Flip-Flop |
| 4.11 | Shift Register |
| 4.12 | Counters |
| 4.13 | Pseudo-Random Sequence Generator |
| 4.14 | Exercises |
As mentioned in the introduction, the electronic circuits for the gates and register described in this chapter will also be presented, which requires some knowledge about transistors. Because MOS transistors are studied later (Chapter 9), a brief introduction is presented here.
Almost all digital circuits are constructed with a type of transistor called MOSFET (metal oxide semiconductor field effect transistor), or simply MOS transistor. Indeed, there are two types of MOS transistors, one called n-channel MOS (or simply nMOS) because its internal channel is constructed with an n-type semiconductor, and the other called p-channel MOS (or simply pMOS) because its channel is of type p.
Regarding their operation, in simple...
