Digital Electronics DigitalElectronics:Principles,DevicesandApplicationsAnilK. Maini ©2007JohnWiley&Sons,Ltd. ISBN: 978-0-470-03214-5 Digital Electronics Principles, Devices and Applications Anil K. Maini Defence Research and Development Organization (DRDO), India Copyright © 2007 John Wiley & Sons Ltd, The Atrium, Southern Gate, Chichester, West Sussex PO19 8SQ, England Telephone +44 1243 779777 Email (for orders and customer service enquiries): [email protected] Visit our Home Page on www.wiley.com All Rights Reserved. No part of this publication may be reproduced, stored in a retrieval system or transmitted in any form or by any means, electronic, mechanical, photocopying, recording, scanning or otherwise, except under the terms of the Copyright, Designs and Patents Act 1988 or under the terms of a licence issued by the Copyright Licensing Agency Ltd, 90 Tottenham Court Road, London W1T 4LP, UK, without the permission in writing of the Publisher. Requests to the Publisher should be addressed to the Permissions Department, John Wiley & Sons Ltd, The Atrium, Southern Gate, Chichester, West Sussex PO19 8SQ, England, or emailed to [email protected], or faxed to (+44) 1243 770620. Designations used by companies to distinguish their products are often claimed as trademarks. All brand names and product names used in this book are trade names, service marks, trademarks or registered trademarks of their respective owners. The Publisher is not associated with any product or vendor mentioned in this book. This publication is designed to provide accurate and authoritative information in regard to the subject matter covered. It is sold on the understanding that the Publisher is not engaged in rendering professional services. If professional advice or other expert assistance is required, the services of a competent professional should be sought. Other Wiley Editorial Offices John Wiley & Sons Inc., 111 River Street, Hoboken, NJ 07030, USA Jossey-Bass, 989 Market Street, San Francisco, CA 94103-1741, USA Wiley-VCH Verlag GmbH, Boschstr. 12, D-69469 Weinheim, Germany John Wiley & Sons Australia Ltd, 42 McDougall Street, Milton, Queensland 4064, Australia John Wiley & Sons (Asia) Pte Ltd, 2 Clementi Loop #02-01, Jin Xing Distripark, Singapore 129809 John Wiley & Sons Canada Ltd, 6045 Freemont Blvd, Mississauga, ONT, Canada L5R 4J3 Wiley also publishes its books in a variety of electronic formats. Some content that appears in print may not be available in electronic books. Anniversary Logo Design: Richard J. Pacifico Library of Congress Cataloging in Publication Data Maini, Anil Kumar. Digital electronics : principles, devices, and applications / Anil Kumar Maini. p. cm. Includes bibliographical references and index. ISBN 978-0-470-03214-5 (Cloth) 1. Digital electronics. I. Title. TK7868.D5M275 2007 621.381—dc22 2007020666 British Library Cataloguing in Publication Data A catalogue record for this book is available from the British Library ISBN 978-0-470-03214-5 (HB) Typeset in 9/11pt Times by Integra Software Services Pvt. Ltd, Pondicherry, India Printed and bound in Great Britain by Antony Rowe Ltd, Chippenham, Wiltshire This book is printed on acid-free paper responsibly manufactured from sustainable forestry in which at least two trees are planted for each one used for paper production. In the loving memory of my father, Shri Sukhdev Raj Maini, who has been a source of inspiration, courage and strength to me to face all challenges in life, and above all instilled in me the value of helping people to make this world a better place. Anil K. Maini Contents Preface xxi 1 Number Systems 1 1.1 Analogue Versus Digital 1 1.2 Introduction to Number Systems 2 1.3 Decimal Number System 2 1.4 Binary Number System 3 1.4.1 Advantages 3 1.5 Octal Number System 4 1.6 Hexadecimal Number System 4 1.7 Number Systems – Some Common Terms 4 1.7.1 Binary Number System 4 1.7.2 Decimal Number System 5 1.7.3 Octal Number System 5 1.7.4 Hexadecimal Number System 5 1.8 Number Representation in Binary 5 1.8.1 Sign-Bit Magnitude 5 1.8.2 1’s Complement 6 1.8.3 2’s Complement 6 1.9 Finding the Decimal Equivalent 6 1.9.1 Binary-to-Decimal Conversion 6 1.9.2 Octal-to-Decimal Conversion 6 1.9.3 Hexadecimal-to-Decimal Conversion 7 1.10 Decimal-to-Binary Conversion 7 1.11 Decimal-to-Octal Conversion 8 1.12 Decimal-to-Hexadecimal Conversion 9 1.13 Binary–Octal and Octal–Binary Conversions 9 1.14 Hex–Binary and Binary–Hex Conversions 10 1.15 Hex–Octal and Octal–Hex Conversions 10 1.16 The Four Axioms 11 1.17 Floating-Point Numbers 12 1.17.1 Range of Numbers and Precision 13 1.17.2 Floating-Point Number Formats 13 viii Contents Review Questions 17 Problems 17 Further Reading 18 2 Binary Codes 19 2.1 Binary Coded Decimal 19 2.1.1 BCD-to-Binary Conversion 20 2.1.2 Binary-to-BCD Conversion 20 2.1.3 Higher-Density BCD Encoding 21 2.1.4 Packed and Unpacked BCD Numbers 21 2.2 Excess-3 Code 21 2.3 Gray Code 23 2.3.1 Binary–Gray Code Conversion 24 2.3.2 Gray Code–Binary Conversion 25 2.3.3 n-ary Gray Code 25 2.3.4 Applications 25 2.4 Alphanumeric Codes 27 2.4.1 ASCII code 28 2.4.2 EBCDIC code 31 2.4.3 Unicode 37 2.5 Seven-segment Display Code 38 2.6 Error Detection and Correction Codes 40 2.6.1 Parity Code 41 2.6.2 Repetition Code 41 2.6.3 Cyclic Redundancy Check Code 41 2.6.4 Hamming Code 42 Review Questions 44 Problems 45 Further Reading 45 3 Digital Arithmetic 47 3.1 Basic Rules of Binary Addition and Subtraction 47 3.2 Addition of Larger-Bit Binary Numbers 49 3.2.1 Addition Using the 2’s Complement Method 49 3.3 Subtraction of Larger-Bit Binary Numbers 52 3.3.1 Subtraction Using 2’s Complement Arithmetic 53 3.4 BCD Addition and Subtraction in Excess-3 Code 57 3.4.1 Addition 57 3.4.2 Subtraction 57 3.5 Binary Multiplication 58 3.5.1 Repeated Left-Shift and Add Algorithm 59 3.5.2 Repeated Add and Right-Shift Algorithm 59 3.6 Binary Division 60 3.6.1 Repeated Right-Shift and Subtract Algorithm 61 3.6.2 Repeated Subtract and Left-Shift Algorithm 62 3.7 Floating-Point Arithmetic 64 3.7.1 Addition and Subtraction 65 3.7.2 Multiplication and Division 65 Contents ix Review Questions 67 Problems 68 Further Reading 68 4 Logic Gates and Related Devices 69 4.1 Positive and Negative Logic 69 4.2 Truth Table 70 4.3 Logic Gates 71 4.3.1 OR Gate 71 4.3.2 AND Gate 73 4.3.3 NOT Gate 75 4.3.4 EXCLUSIVE-OR Gate 76 4.3.5 NAND Gate 79 4.3.6 NOR Gate 79 4.3.7 EXCLUSIVE-NOR Gate 80 4.3.8 INHIBIT Gate 82 4.4 Universal Gates 85 4.5 Gates with Open Collector/Drain Outputs 85 4.6 Tristate Logic Gates 87 4.7 AND-OR-INVERT Gates 87 4.8 Schmitt Gates 88 4.9 Special Output Gates 91 4.10 Fan-Out of Logic Gates 95 4.11 Buffers and Transceivers 98 4.12 IEEE/ANSI Standard Symbols 100 4.12.1 IEEE/ANSI Standards – Salient Features 100 4.12.2 ANSI Symbols for Logic Gate ICs 101 4.13 Some Common Applications of Logic Gates 102 4.13.1 OR Gate 103 4.13.2 AND Gate 104 4.13.3 EX-OR/EX-NOR Gate 104 4.13.4 Inverter 105 4.14 Application-Relevant Information 107 Review Questions 109 Problems 110 Further Reading 114 5 Logic Families 115 5.1 Logic Families – Significance and Types 115 5.1.1 Significance 115 5.1.2 Types of Logic Family 116 5.2 Characteristic Parameters 118 5.3 Transistor Transistor Logic (TTL) 124 5.3.1 Standard TTL 125 5.3.2 Other Logic Gates in Standard TTL 127 5.3.3 Low-Power TTL 133 5.3.4 High-Power TTL (74H/54H) 134 5.3.5 Schottky TTL (74S/54S) 135 x Contents 5.3.6 Low-Power Schottky TTL (74LS/54LS) 136 5.3.7 Advanced Low-Power Schottky TTL (74ALS/54ALS) 137 5.3.8 Advanced Schottky TTL (74AS/54AS) 139 5.3.9 Fairchild Advanced Schottky TTL (74F/54F) 140 5.3.10 Floating and Unused Inputs 141 5.3.11 Current Transients and Power Supply Decoupling 142 5.4 Emitter Coupled Logic (ECL) 147 5.4.1 Different Subfamilies 147 5.4.2 Logic Gate Implementation in ECL 148 5.4.3 Salient Features of ECL 150 5.5 CMOS Logic Family 151 5.5.1 Circuit Implementation of Logic Functions 151 5.5.2 CMOS Subfamilies 165 5.6 BiCMOS Logic 170 5.6.1 BiCMOS Inverter 171 5.6.2 BiCMOS NAND 171 5.7 NMOS and PMOS Logic 172 5.7.1 PMOS Logic 173 5.7.2 NMOS Logic 174 5.8 Integrated Injection Logic (I2L) Family 174 5.9 Comparison of Different Logic Families 176 5.10 Guidelines to Using TTL Devices 176 5.11 Guidelines to Handling and Using CMOS Devices 179 5.12 Interfacing with Different Logic Families 179 5.12.1 CMOS-to-TTL Interface 179 5.12.2 TTL-to-CMOS Interface 180 5.12.3 TTL-to-ECL and ECL-to-TTL Interfaces 180 5.12.4 CMOS-to-ECL and ECL-to-CMOS Interfaces 183 5.13 Classification of Digital ICs 183 5.14 Application-Relevant Information 184 Review Questions 185 Problems 185 Further Reading 187 6 Boolean Algebra and Simplification Techniques 189 6.1 Introduction to Boolean Algebra 189 6.1.1 Variables, Literals and Terms in Boolean Expressions 190 6.1.2 Equivalent and Complement of Boolean Expressions 190 6.1.3 Dual of a Boolean Expression 191 6.2 Postulates of Boolean Algebra 192 6.3 Theorems of Boolean Algebra 192 6.3.1 Theorem 1 (Operations with ‘0’ and ‘1’) 192 6.3.2 Theorem 2 (Operations with ‘0’ and ‘1’) 193 6.3.3 Theorem 3 (Idempotent or Identity Laws) 193 6.3.4 Theorem 4 (Complementation Law) 193 6.3.5 Theorem 5 (Commutative Laws) 194 6.3.6 Theorem 6 (Associative Laws) 194 6.3.7 Theorem 7 (Distributive Laws) 195 Contents xi 6.3.8 Theorem 8 196 6.3.9 Theorem 9 197 6.3.10 Theorem 10 (Absorption Law or Redundancy Law) 197 6.3.11 Theorem 11 197 6.3.12 Theorem 12 (Consensus Theorem) 198 6.3.13 Theorem 13 (DeMorgan’s Theorem) 199 6.3.14 Theorem 14 (Transposition Theorem) 200 6.3.15 Theorem 15 201 6.3.16 Theorem 16 201 6.3.17 Theorem