Lecture No. 1

Computer Logic Design

About the Course

Title:– Computer Logic Design

• Pre-requisites:– None

• Required for future courses:– Computer Organization & Architecture– Assembly Language– Operating System

Logic & Computer Design FundamentalsLogic & Computer Design Fundamentals(Second Edition Updated; Third Indian Reprint 2003)(Second Edition Updated; Third Indian Reprint 2003)

ISBN: 81-7808-334-5ISBN: 81-7808-334-5

M. Morris Mano & Charles R. Kime

Digital FundamentalsDigital Fundamentals(Eighth Edition; First Indian Reprint 2003)(Eighth Edition; First Indian Reprint 2003)

ISBN: 81-7808-876-2ISBN: 81-7808-876-2

Thomas L. Floyd

About the Course Textbooks

Why Study It?

• you want to be a computer scientist

• it makes you a better programmer

• performance: programming is more than just getting the answer

• it's fun to learn how things work

• you may need to buy a computer someday

More about the Course• Core-course• Foundation for advanced courses

– Advanced Digital Design– Computer Architecture

• Foundation for a career track– Area for advanced design and learning

• System on Chip (SoC)• Active research area,

– A profession, highly in demand in the industry– Offshoots into logic synthesis, design verification,

product and test engineering

• In short: An opportunity!! Make the best of it!!

Course Content

• Analog & Digital World• Number Systems• Boolean Algebra & Logic Circuits

– Logic gates– Logic minimization

• Combinational Logic– Memory-less circuits– De/mux, de/encoders, shifters, adder, multiplier

• Sequential Logic– Latches, flip-flops– Registers & Counters– State Machine Design

• Semiconductor Technologies (Switch & CMOS design)

Course Content

• Memory Systems– Register– RAM– ROM– Caches

• Programmable Logic Devices– FPGA– PLA– PAL

• Instruction Set Architecture– Register Transfers and Datapaths– Sequencing & Control

Introduction

Introduction

• The course is about the design and Implementation of Digital Systems

• What is a digital system• A system is an entity that responds to an input

• The output is a modified form of the input

input outputsystem

Introduction

• A simple electronic circuit

• The camera Image

Introduction

• The speech recognition system

• Calculators• Computer• Audio CD Player• Mobile Phones

• Radar Detection System• Speech/Image Recognition System• Industrial Control Systems, etc.

Identified

Introduction

• Digital Systems– The input and output of the system are digital

signals– It is important to know about digital signals– Intensity of light– time– distance

Analog World

Most things in nature:

• Continuous Values

• Temperature

• Speed

• Intensity of Light

• Distance

• Colors

Digital World

• Discrete set of values

• Typically, achieved through sampling of analog quantities

• Coded representation of values

Digital World (cont)

• Widespread usage• Computers and internet driving world economy• Internet doubles in size every year• Moore’s law: processors double in speed every 18

months• Latest processors have millions of transistors and

run billions of cycles per sec• More traditional analog systems migrating to

digital. Why?

Analog Signal

– value of signal exists at any instant of time– signal may take any value along the vertical axis– occurs in continuous form

Independent variable

Analog Signal

Independent variable

– Sampled analog signal

Digitized Signal

– The value of signal only exists at discrete points in time– The reconstructed signal has sharp edges and corners in

contrast to the original signal which has smooth curves

Independent variable

Under-sampled Digitized Signal

– Number of sample points reduced by half– Loss of information occurs– What about over-sampling?

Independent variable

The Digital Advantage

• Digital data can be processed and transmitted– more efficiently than analog data– More reliable than analog data

• Digital data has a great advantage when storage is necessary e.g.

• Music when converted to digital form can be – stored more compactly – reproduce with great accuracy and clarity than analog

• Noise does not affect digital data nearly as much as it does analog signals.

Representation of Quantities

• Analog Systems– Use and work with voltages or signals that are continuous

• Digital Systems– Discrete values but how many?

– The whole basis of digital electronics is based on the simplicity of the “on/off” or “0/1” model

– All quantities and values must be coded into this bi-level set of “0”s and “1”s

– All storage and transmission of values in a digital system occurs using these two binary digits (bits).

Lecture # 1 (Review)

• Analog– Continuous values

• Digital– Discrete set of values

• Advantages of digital over analog– Can be processed and transmitted more efficiently and

reliably

– Take less space

– Noise does not effect