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CS 303Logic & Digital System

Design- An Overview

Erkay SavaşSabancı University

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Motivation

• Analysis & design of digital electronic circuits

• Why digital circuits?– They are everywhere and generic– digital computers, smart phones, data

communication, digital recording, digital TV, many others

• Fundamental concepts in the design of digital systems

• Basic tools for the design of digital circuits• Logic gates (AND, OR, NOT)

– Boolean algebra

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What is a Digital System?• One characteristic:

– Ability of manipulating discrete elements of information

• A set that has a finite number of elements contains discrete information

• Examples for discrete sets– Decimal digits {0, 1, …, 9}– Alphabet {A, B, …, Y, Z}– Binary digits {0, 1}

• One important problem– how to represent the elements of discrete sets in

physical systems?

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How to Represent?

• In electronics circuits, we have electrical signals– voltage– current

• Different strengths of a physical signal can be used to represent elements of the discrete set.

• Which discrete set?• Binary set is the easiest

– two elements {0, 1}– Just two signal levels: 0 V and 4 V

• This is why we use binary system to represent the information in digital systems.

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Binary System• Binary set {0, 1}

– Th elements of binary set, 0 and 1 are called “binary digits”

– or shortly “bits”.

• How to represent the elements of other discrete sets– Decimal digits {0, 1, …, 9}– Alphabet {A, B, …, Y, Z}

• Elements of any discrete sets can be represented using groups of bits.– 9 ?– A ?

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How Many Bits?

• What is the formulae for number of bits to represent a discrete set of n elements

• {0, 1, 2, 3}– 00 0, 01 1, 10 2, ands 11 3.

• {0, 1, 2, 3, 4, 5, 6, 7}– 000 0, 001 1, 010 2, ands 011 3– 100 4, 101 5, 110 6, ands 111 7.

• The formulae, then,– ?– If n = 9, then ? bits are needed

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Nature of Information

• Is information of discrete nature?

• Sometimes, but usually not.– Anything related to money (e.g. financial computations,

accounting etc) involves discrete information

• In nature, information comes in a continuous form– temperature, humidity level, air pressure, etc.

• Continuous data must be converted (i.e. quantized) into discrete data– lost of some of the information

– We need ADC (DAC)

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General-Purpose Computers

• Best known example for digital systems• Components

– CPU, I/O units, Memory unit

General-purpose computer

CPU Memory I/OOutside world

CPU

Interconnect

FPUMultiplier/

Divider

Control

Registers

ALU

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Textbook & References• Textbook

– M. Morris Mano, & Michael D. Ciletti “Digital Design”, Fourth Edition, Prentice Hall, 2007.

• Other references– M. Morris Mano and Charles R. Kime, “Logic and

Computer Design Fundamentals”, Fourth Edition Prentice Hall, 2007.

– Tens of digital design books

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Lecture• Three hours (2+1) a week (four credits)

• Monday: 12:40 – 13:30 (FENS G077)• Thursday: 15:40 – 16:30 (FENS G077)

• Attendance is a must

– Failing to attend three lectures in which attendance is collected

may result in one letter down in your grade

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Recitation• One hour (two sections)

• A: Thursday: 13:40 – 14:30 (FENS G077)• B: Friday: 13:40 – 14:30 (FENS G029)

• What to do?– Regular lecture (if necessary)– Instructive sessions for lab equipments– Problem solving sessions (e.g. preparatory for

exams)– HDL language sessions

• How to know?– It will be announced

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Laboratory Assignments• Six Sections

– A – Tuesday: 10:40 – 12:30 (FENS 1033)– B – Monday: 08:40 – 10:30 (FENS 1033)– C –Tuesday: 08:40 – 10:30 (FENS 1033)– D –Monday: 13:40 – 15:30 (FENS 1033)– E – Monday: 10:40 – 12:30 (FENS 1033)

• At least four lab assignments• It is obligatory to do all the assignments• Weight: 15%• Work in groups of two

Your Board

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Short Homework Assignments• At times• Weight: 5%

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Project• A big development project where you use

what you learn– Design + implementation

• Weight: 10%• No partial credit• Essential to demonstrate a working version• Works in groups of two

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Exams• Two midterm exams

– Weight: 35%– Midtem I : November– Midterm II : December

• Final exam– Weight: 35%– As scheduled by registration office

• Only one makeup exam– After final exam that substitues exams you missed

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Lab & Term Project• 1st lab: integrated circuits on a breadboard• Other labs: FPGA board

• How to use them:• Informative sessions during recitation hours

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Lab Assistants• Duygu Karaoğlan (FENS 2001)• Hazar A. İlhan• Ecem Ünal • Yusuf Külah• Others

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SUCourse• Will be used for (nearly) everything

– communication media– announcements– lab assignments postings– short homework postings– uploading reports, homework, etc.

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Contact Information• Erkay Savaş

• Place: FENS 1098• e-mail: erkays@sabanciuniv.edu• Use SUCourse, then e-mail• You can call me if it is urgent • Office hours:

– Monday 15:40 – 17:30– Or by appointment– TBA for assistants