Author's Profile Prof. B. Govindarajalu is presently Dean (Computer Studies) at Rajalakshmi Engineering College, Chennai. He is a B.E. in Electronics and Communication Engineering from Regional Engineering College, Trichirappali and M.Tech in Computer Science and Engineering from IIT Bombay. Before joining Rajalakshmi Engineering College he worked with Manipal Engineering College; IIT Bombay; ORG Systems (Baroda) Infotech Ltd. (Chennai); and Microcode (Chennai). He has over 37 years of experience in computer hardware and IT industry covering design and development, manufacturing, maintenance, technical support, teaching and training. He has developed a series of microprocessor-based products such as the IBM System 360 Compatible Data Communications Multiplexer, VDU System Console and Terminal Processing Unit/Concentrator. After 15 years of industrial experience, he founded Microcode, an IT firm specializing in PC hardware and networking training and development of diagnostic tools where he trained nearly 10,000 engineers in PC maintenance. He has developed a series of certification tests on computer architecture, PC hardware and networking. He has also taught personal computer hardware and architecture as visiting professor at several institutions such as Rajalakshmi Engineering College, Crescent Engineering College, Jaya Engineering College, Vellore Institute of Technology and Sastha Institute of Technology. He has conducted career courses on computer networking for Rajalakshmi Engineering College, Velammal Engineering College, Kongu Engineering College, J J College of Engineering and SSN College of Engineering. He has been a specialist for a UNESCO project on curriculum development. He has also served as a member of the Board of Studies at PSG College of Technology, Coimbatore. He has authored two computer books published by Tata McGraw Hill: 1. IBM PC and Clones: Hardware, Troubleshooting and Maintenance 2. Computer Architecture and Organization: Design Principles and Applications He is working on a book titled Advanced Microprocessor Architectures. His interests include Tamil literature, spirituality and meditation. Govindarajalu’s future plans include launching a technical magazine catering to the needs of engineering students. He may be contacted at [email protected]. B. Govindarajalu (Founder-CEO, MICROCODE, Chennai), Dean (Computer Studies) Rajalakshmi Engineering College Chennai Tata McGraw-Hill Publishing Company Limited NEW DELHI McGraw-Hill Offices New Delhi New York St Louis San Francisco Auckland Bogotá Caracas Kuala Lumpur Lisbon London Madrid Mexico City Milan Montreal San Juan Santiago Singapore Sydney Tokyo Toronto Published by the Tata McGraw Hill Education Private Limited, 7 West Patel Nagar, New Delhi 110 008. Copyright © 2010, 2009, 2007, 2006, 2005 by Tata McGraw Hill Education Private Limited. No part of this publication may be reproduced or distributed in any form or by any means, electronic, mechanical, photocopying, recording, or otherwise or stored in a database or retrieval system without the prior written permission of the publishers. The program listings (if any) may be entered, stored and executed in a computer system, but they may not be reproduced for publication. This edition can be exported from India only by the publishers, Tata McGraw Hill Education Private Limited. ISBN (13): 978-0-07-015277-9 ISBN (10): 0-07-015277-2 Vice President and Managing Director—Asia-Pacific Region: Ajay Shukla Executive Publisher—Professional: R Chandra Sekhar Production Executive: Rita Sarkar Manager—Sales and Marketing: S Girish Deputy Marketing Manager—Science, Technology & Computing: Rekha Dhyani General Manager—Production: Rajender P Ghansela Assistant General Manager—Production: B L Dogra Information contained in this work has been obtained by Tata McGraw-Hill, from sources believed to be reliable. However, neither Tata McGraw-Hill nor its authors guarantee the accuracy or completeness of any information published herein, and neither Tata McGraw-Hill nor its authors shall be responsible for any errors, omissions, or damages arising out of use of this information. This work is published with the understanding that Tata McGraw-Hill and its authors are supplying information but are not attempting to render engineering or other professional services. If such services are required, the assistance of an appropriate professional should be sought. Typeset at Script Makers, 19, A1-B, DDA Market, Paschim Vihar, New Delhi 110 063, and printed at Sai Printo Pack, A-102/4, Okhla Industrial Area, Phase II, New Delhi 110020. Cover Design: Kapil Gupta Cover Printer: Sai Printo Pack RAZYCRBZDXQYY To my in-laws Mr. N. Gopalakrishnan, my father-in-law and Mrs. Leelavathy Gopalakrishnan who have always encouraged and supported me in all my new ventures and my recently discovered friend Mr. G.R. Krishnamoorthy (EX OM, CCS Ltd. Chittoor) whose simplicity, honesty and hardworking nature have deeply impressed me Foreword I I am extremely happy to write the Foreword to the second edition of B. Govindarajalu’s book on Computer Architecture Organization: Design Principles and Applications. His earlier book, IBM PC and Clones: Hardware, Troubleshooting and Maintenance, was well received—not only in academic circles but also in the computer maintenance industry. The first edition of this book was highly appreciated and lays emphasis upon learning of fundamental concepts through easily understandable text. Good selection of problems with their solutions helps students to grasp the intricacies of the subject and instill a sense of self study, creative thinking and review. The second edition of this book covers important units of a computer in a very comprehensible manner and therefore, will be useful as a Level I book for undergraduate students pursuing courses in electrical engineering, electronics, computers and IT. All the chapters are concise and are supported by a detailed background. The author’s vast experience and sound theoretical and practical knowledge is reflected in the material covered. This book will serve as a valuable guide for students keen on mastering the organization of computer architecture. Prof. S.S.S.P. Rao Chief Mentor and Advisor, CMC Limited, Hyderabad Former Professor of Department of Computer Science and Engineering, IIT Bombay Visiting Professor of Department of Computer Science and Engineering, IIT Hyderabad Foreword II There are many good books which cover the vast and ever-growing area of Computer Architecture but not all cover the entire gamut of emerging technologies in this domain. Also, at times the coverage as well as language do not suit Indian academic community. Computer Architecture and Organization: Design Principles and Applications written by one of my colleagues, during my earlier stint, has addressed the issues lucidly and presented the technical content relevant to most of the Indian universities. In the second edition, few additional chapters covering advanced topics such as Parallelism and Super Scalar Architecture have been included. The author who has rich experience both in academia and industry has ensured that the overall pedagogic content is easy to follow and comprehend. I recommend this book for teachers, university students and professionals. Dr. K. Sarukesi Vice-Chancellor Hindustan Institute of Technology and Science, Chennai Preface to the Second Edition Computer design or computer architecture is an interesting subject. With the rapid evolution of computer science, an increasingly diverse group of students is studying the subject of computer architecture. Though interesting and simple a majority of students consider it to be highly complex. Having worked both in industry and academic institutions with a range of computers starting from second generation systems, I decided to help in such a way that even a student of average IQ can understand it. The target audience of this book includes readers who want to learn basic computer organization as well as those who want to design a computer. It can also be used by professionals as a reference. The book is intended as a text book for undergraduate students of computer science, information technology and electrical and electronics engineering. This book serves as a first level course on computer architecture/ organization. As a prerequisite, the reader is expected to be familiar with computer program- ming. It is assumed that the reader does not know any specific programming language. In addition, exposure to digital electronics is helpful. For the benefit of those who have no knowledge of this, an annexure presents an overview of essential topics of digital electronics. ORGANIZATION OF THE BOOK This book is organized with a three layer structure shown here. BasicProcessor Pipelining Ch4,5,6 Ch12 Superscalarand Foundation Memory AdvancedProcessor Ch1,2,3 Ch7,8,9 Ch13,14,15 Multiprocessors I/OSubsystems andServers Ch10,11 Ch16 Layer1 Layer2 Layer3 Foundation Subsystems Parallelism xii Preface to the Second Edition Though the chapters are organized in a linear sequence for reading, alternate layouts are possible. The first three chapters form the top layer that provides a foundation to computer architecture and organization. After studying these, the remaining chapters can be covered in any sequence shown in the figure. The middle layer consisting of chapters 4–11 describes the design of different subsystems of the computer. The last layer covers special topics that deal with parallelism and advanced computer architectures. This layer comprises chapters 12–16. This modular arrangement facilitates quick and standalone reference by professionals for select topics. CHAPTER DESCRIPTION Layer 1: Foundation Chapter 1 introduces the basics of a present-day computer without describing the design aspects. It defines the computer's hardware and software layers and provides an overview of Interrupt Concept and I/O techniques. Chapter 1 also introduces techniques used in high performance computers in addition to system performance measurement. Chapter 2 gives an overview of the history of computer and its evolution. Generations of computers are defined along with the new features of each generation. Chapter 3 describes the basic attributes of a computer such as instruction set, addressing modes and data types. It also distinguishes between RISC and CISC architectures. Layer 2: Subsystems Chapter 4 focuses on data path organization and ALU design. Both fixed-point data path and floating-point data path are covered. Chapter 5 describes the algorithms for fixed-point and floating-point arithmetic. It also defines serial and parallel adders. Chapter 6 presents techniques of designing a control unit. Both hardwired and micro- programmed control units are covered. It also describes micro operations and register transfer language. Single bus processor as well as multiple bus processor are discussed. Chapter 7 focuses on memory technologies and main memory design. Chapter 8 describes various memory enhancement techniques for tackling performance and capacity issues. Cache memory, virtual memory and memory interleaving are the major topics covered. Chapter 9 deals with secondary storage devices such as magnetic disks and tapes apart from optical media. In addition, RAID levels and RAID controllers are discussed. Chapter 10 presents the sequence of communication between the internal units. Different I/O controllers, bus standards, Interrupt concept and I/O techniques are described. Chapter 11 describes the commonly used peripheral devices. Preface to the Second Edition xiii Layer 3: Parallelism and Advanced Architectures Chapter 12 gives an elaborate study of parallelism and concurrency in computers with special emphasis on pipelining. The concept of RISC processors is also covered here. Chapters 13–16 describe advanced architectures found in uniprocessing and multiprocessing. Chapter 13 deals with the superscalar architecture of uniprocessors. Dynamic scheduling techniques are discussed. Chapter 14 describes VLIW and EPIC architectures. Chapter 15 deals with vector computing and array processing. Chapter 16 describes multiprocessors and cache coherency in addition to reliability and fault tolerance concepts and techniques. Additions in Second Edition The Second Edition aims to: · Enhance the suitability of the book according to the syllabi of the UG course on Computer Organization and Architecture offered by most universities, especially Anna University, Chennai. · Update the technical content according to the changes in the industry since the publication of the first edition in 2003. · Improve quality. Two major changes have been carried out in the Second Edition: · Chapters 11 and 12 of the first edition have been completely revised and reorga- nized in the second edition as five different chapters (12 to 16). · Part of the contents of Chapter 10 in the first edition, dealing with magnetic disk, tape and optical disk, have been shifted to Chapter 11 in the second edition. In addition, several minor additions have been made to the contents in almost all the chapters. Some of these are identified in the following table: Chapter no. Topics added/modified Relevant section 1 System Performance Measurement and 1.13 Response Time 3 Hardware-Software Interface 3.8 4 Floating-point Numbers 4.4 5 Building Long Adder 5.3 6 Synchronous and Asynchronous Control Unit 6.7 6 Clocking and Synchronization 6.3 6 Single Cycle and Multicycle Design 6.3 6 Single Bus and Multiple Bus Processor 6.4, 6.5 9 End-to-End Data Protection 9.6.8 9 RAID 9.7 9 Magnetic Tape 9.8 10 PCI Bus 10.8 10 SCSI 10.8 (Contd.)