# Computer Systems Digital Design, Fundamentals of Computer Architecture and Assembly Language

This textbook is the result of my experiences teaching computer systems at the Computer Science Department at Southern Connecticut State University since 1986. The book is divided into three sections: Digital Design, Introduction to Computer Architecture and Memory, and ARM Architecture and Assembly Language. The Digital Design section includes a laboratory manual with 12 experiments using Logisim software to enforce important concepts. The ARM Architecture and Assembly Language section includes several examples of assembly langauge programs using Keil μVision 5 development tools.

This book is written primarily for a one semester course as an introduction to computer hardware and assembly language for students majoring in Computer Science, Information Systems and Engineering Technology. Organization The material of this book is presented in such a way that no special background is required to nderstand the topics.
Chapter 1 – Signals and Number Systems: Analog Signal, Digital Signal, Binary Numbers, Addition and Subtraction of binary numbers, IEEE 754 Floating Point epresentations, ASCII, Unicode, Serial Transmission, and Parallel Transmission.
Chapter 2 – Boolean Logics and Logic Gates: Boolean Logics, Boolean Algebra Theorems, Logic Gates, Integrate Circuit (IC), Boolean Function, Truth Table of a function and using Boolean Theorems to simplify Boolean Functions.

#### Signals and Number Systems

Objectives: After completing this chapter, you should be able to:
• Explain the basic components of a computer.
• Distinguish between analog and digital signal.
• Learn the characteristics of signal.
• Convert decimal numbers to binary and vice versa.
• Learn addition and subtraction of binary numbers.
• Represent floating numbers in binary.
• Convert from binary to hexadecimal and vice versa.
• Distinguish between serial and parallel transmission.
Numerical values have become an integral part of our daily lives. Numerical values can be represented by analog or digital; examples include an analog watch, digital watch, or thermometer. The following are advantages of digital representation of numerical values compared to analog representation:
1. Digital representation is more accurate.
2. Digital information are easier to store
3. Digital systems are easier to design.
4. Noise has less effect.
5. Digital systems can easily be fabricated in an integrated circuit.
A digital signal is a discrete signal (step by step), and an analog signal is a continuous signal. Digital systems are widely used and its applications can be seenin computers, calculators, and cell phones. In a digital system, information is transferred between components of the digital system in the form of digital signals.