Building Embedded Systems

Transcription

1 Building Embedded Systems Programmable Hardware Changyi Gu

2 Building Embedded Systems Changyi Gu San Diego California, USA ISBN-13 (pbk): ISBN-13 (electronic): DOI / Library of Congress Control Number: Copyright 2016 by Changyi Gu This work is subject to copyright. All rights are reserved by the Publisher, whether the whole or part of the material is concerned, specifically the rights of translation, reprinting, reuse of illustrations, recitation, broadcasting, reproduction on microfilms or in any other physical way, and transmission or information storage and retrieval, electronic adaptation, computer software, or by similar or dissimilar methodology now known or hereafter developed. Exempted from this legal reservation are brief excerpts in connection with reviews or scholarly analysis or material supplied specifically for the purpose of being entered and executed on a computer system, for exclusive use by the purchaser of the work. Duplication of this publication or parts thereof is permitted only under the provisions of the Copyright Law of the Publisher s location, in its current version, and permission for use must always be obtained from Springer. Permissions for use may be obtained through RightsLink at the Copyright Clearance Center. Violations are liable to prosecution under the respective Copyright Law. Trademarked names, logos, and images may appear in this book. Rather than use a trademark symbol with every occurrence of a trademarked name, logo, or image we use the names, logos, and images only in an editorial fashion and to the benefit of the trademark owner, with no intention of infringement of the trademark. The use in this publication of trade names, trademarks, service marks, and similar terms, even if they are not identified as such, is not to be taken as an expression of opinion as to whether or not they are subject to proprietary rights. While the advice and information in this book are believed to be true and accurate at the date of publication, neither the authors nor the editors nor the publisher can accept any legal responsibility for any errors or omissions that may be made. The publisher makes no warranty, express or implied, with respect to the material contained herein. Managing Director: Welmoed Spahr Lead Editor: Jonathan Gennick Development Editor: Douglas Pundick Technical Reviewer: Brendan Horan Editorial Board: Steve Anglin, Pramila Balen, Louise Corrigan, Jim DeWolf, Jonathan Gennick, Robert Hutchinson, Celestin Suresh John, Michelle Lowman, James Markham, Susan McDermott, Matthew Moodie, Jeffrey Pepper, Douglas Pundick, Ben Renow-Clarke, Gwenan Spearing Coordinating Editor: Jill Balzano Copy Editor: Kezia Endsley Compositor: SPi Global Indexer: SPi Global Artist: SPi Global Distributed to the book trade worldwide by Springer Science+Business Media New York, 233 Spring Street, 6th Floor, New York, NY Phone SPRINGER, fax (201) , orders-ny@springer-sbm.com, or visit Apress Media, LLC is a California LLC and the sole member (owner) is Springer Science + Business Media Finance Inc (SSBM Finance Inc). SSBM Finance Inc is a Delaware corporation. For information on translations, please rights@apress.com, or visit Apress and friends of ED books may be purchased in bulk for academic, corporate, or promotional use. ebook versions and licenses are also available for most titles. For more information, reference our Special Bulk Sales ebook Licensing web page at Any source code or other supplementary material referenced by the author in this text is available to readers at For detailed information about how to locate your book s source code, go to Printed on acid-free paper

3 To those who enjoy doing things that are otherwise meaningless in the eyes of many.

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5 Contents at a Glance About the Author...xv About the Technical Reviewer...xvii Acknowledgments...xix Introduction...xxi Chapter 1: The Whole Picture... 1 Chapter 2: Power On and Bootloader... 5 Chapter 3: Inside the CPU Chapter 4: RAM, DMA, and Interrupt Chapter 5: Bus Architecture Chapter 6: Firmware Coding in C Chapter 7: Firmware Coding in the C++ and Script Languages Chapter 8: Building and Deployment Chapter 9: Field-Programmable Gate Arrays Chapter 10: System on Programmable Chip (SOPC) Chapter 11: De-Bounce, Power Management, and Display Chapter 12: Fixed Point Math Chapter 13: Popular Ways of Console Communications: Prepare the Tools Chapter 14: Work Flow Index v

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7 Contents About the Author...xv About the Technical Reviewer...xvii Acknowledgments...xix Introduction...xxi Chapter 1: The Whole Picture... 1 Organization of the Book... 3 Companion Materials for this Book... 4 References... 4 Chapter 2: Power On and Bootloader... 5 What Happens After Powering On... 5 What Does Bootloader Do?... 7 User Image (ROM Image)... 8 Image of Embedded OS... 8 Image of Object File... 9 Flash Image and XIP (Execute In Place) Flash Memory Burn the Flash (PROM Program) NOR Flash and NAND Flash Pre-Loader Flash File System Summary...24 References...25 vii

8 CONTENTS Chapter 3: Inside the CPU Von Neumann Architecture and Memory Barrier Harvard Architecture, Modified Harvard Architecture CISC and RISC SIMD/VLIW...34 CPU Debugging CPU Simulator ROM Monitor Introduction to ICE (In Circuit Emulator) Non-JTAG ICE JTAG-Based ICE Using Breakpoints Trace Summary...46 References...46 Chapter 4: RAM, DMA, and Interrupt Types of Random Access Memory NVRAM (Non-Volatile Random Access Memory) Traditional SRAM: Intel 8080 vs. Motorola DDR SDRAM (Dual Date Rate Synchronous Dynamic RAM) QDR SRAM Other Types of RAM PIO and DMA PIO DMA and MMU Memory Allocation for DMA Cache/Write Buffer and Memory Incoherence...60 Interrupt Interrupt Mechanism Shared Interrupt viii

9 CONTENTS VIC (Vectored Interrupt Controller) Interrupt from Watchdog Timer Message Signaled Interrupt (MSI) Summary...68 References...68 Chapter 5: Bus Architecture Bus with System Synchronous Timing Bus with Source Synchronous Timing From Parallel Bus to Serial Bus The Drawbacks of Parallel Bus The Benefit of Differential Serial Link Implementation of Differential Serial Link Out-of-band Clocking Embedded Clocking b/10b Encoding and Signal Conditioning Bus Standards RS I2C and SMBus SPI PCI overview USB overview USB device implementation Ethernet Summary References Chapter 6: Firmware Coding in C Overview The Confusion of Tongues ix

10 CONTENTS Firmware Coding in the C Language Explicit Type of Bit-Width Align the Data Structure Debug Print Compile Time Assertion Volatile, Const, and Peripheral Registers Finite State Machine Firmware Version and About Signature Summary References Chapter 7: Firmware Coding in the C++ and Script Languages Firmware Coding in C Enhancements to the C Language New Concepts Offered by C C/C++ Mixed Programming Script Languages Overview Compiled Versus Script Languages Tcl/Tk, Expect, Perl, and Python Documentation Generator Summary References Chapter 8: Building and Deployment The Build Process Makefile Basics Simple Makefile Makefiles that Handle Dependency Recursive Makefiles Makefile with Kernel Configuration Language Other Ways to Implement a Build Process x

11 CONTENTS Embedded OS Choose an Embedded OS Embedded Linux Development Flow Development Machine Setup Summary References Chapter 9: Field-Programmable Gate Arrays Hardware Overview FPGA CPU vs. FPGA Verilog vs. VHDL Bi-Directional Bus Clock Reset CDC (Clock Domain Crossing) Area-Time Tradeoff and AT 2 Boundary Inter-FPGA Communication Protect Your IP Encrypt Your Source Code Obfuscate Your Source Code Protect Your Bit Stream Anti-Tamper Summary References Chapter 10: System on Programmable Chip (SOPC) Economics MCU vs. Soft MCU MCU Plus External Peripherals Multiple Processors xi

12 CONTENTS Processor Core Interconnection Design and Use Your Own 1T History Patents and Copyrights Address Spaces CISC Instruction Set RISC Implementation Compilers and Debuggers Summary References Chapter 11: De-Bounce, Power Management, and Display PoR (Power-On Reset) and Switch De-Bounce Power-On Reset Switch De-Bounce Power Management LCD Display How LCD Works LCD Programming Interfaces Using Touchscreens Resistive Touchscreens Capacitive Touchscreen Summary References Chapter 12: Fixed Point Math Q Format Two s Complement and Symmetric Range Basic Operations Rounding and Truncation Saturation xii

13 CONTENTS Negation Absolute Value Unsigned Division Sin/Cos Table CORDIC Algorithm Basic Ideas Circular Coordinate System Linear Coordinate System Hyperbolic Coordinate System Summary References Chapter 13: Popular Ways of Console Communications: Prepare the Tools Software Tools Cygwin Text Editor File/Folder Comparison Version Control Issue (Bug) Tracking Terminal Emulator Virtual Machine Cluster Workload Management Hardware Tools Oscilloscope Logic Analyzer Bus/Protocol Analyzer-Exerciser Power Analyzer Multimeter Others Summary References xiii

14 CONTENTS Chapter 14: Work Flow Project Inception System Design Software Hardware Mechanical Manufacturing and Quality Control Summary References Index xiv

15 About the Author Changyi Gu has worked for multiple high-tech companies across California for over 15 years. He is also the founder of PulseRain Technology, LLC, a company that excels at FPGA-based embedded systems. He started out his career in firmware development. With a deep passion in engineering, he later devoted himself to wireless hardware and programmable logic. Thus, he is one of the lucky few who gets to watch things closely on both the software and hardware sides. Changyi graduated from the University of Southern California with a master s degree in VLSI. And he holds another master s degree in Communications and a bachelor s degree in CS from Shanghai Jiaotong University, China. In his leisure time, he likes to tinker with things. xv

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17 About the Technical Reviewer Brendan Horan is a hardware fanatic, with a full high rack of all types of machine architectures in his home. He has more than 10 years of experience working with large UNIX systems and tuning the underlying hardware for optimal performance and stability. Brendan s love for all forms of hardware has helped him throughout his IT career, from fixing laptops to tuning servers and their hardware in order to suit the needs of high-availability designs and ultra low-latency applications. Brendan takes pride in the Open Source Movement and is happy to say that every computer in his house is powered by open source technology. He resides in Hong Kong with his wife, Vikki, who continues daily to teach him more Cantonese. xvii

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19 Acknowledgments Family: First of all, I would like to thank my parents for nurturing my interest in engineering since childhood, which has given rise to this book. I would also like to thank my wife and daughter for bearing with my nocturnal lifestyle for so long. The midnight oil I burned is in your names. Tech Reviewers: Special thanks to Brendan Horan for his sound suggestions to my writing. Those feedbacks are highly valued. And I also owe a big thank you to my ex-coworkers Cynthia Xu and On Wa Yeung for offering assistance in reading my book. I really appreciate your kind help. Editors: A hug to Jonathan Gennick for giving me the opportunity on this book, and for his passion in embedded systems. I really appreciate your prompt response to my book proposal and your hard work throughout the whole project. I would also like to thank Jill Balzano for her wonderful job managing the project. This book will not be possible without you. My development editor, Douglas Pundick, offered valuable suggestions to save me from possible embarrassment. Your thoroughness is appreciated. And to the rest of Apress team thanks for your hard work! Readers: Thank you for choosing my book! xix

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21 Introduction Almost no one comes down here (the engineering level) unless, of course, there is a problem. That s how it is with people. Nobody cares how it works as long as it works. I like it down here. The Matrix Reloaded (2003) Embedded systems are conspicuous by their omnipresence. But most people take them for granted despite the fact that behind every system is a design that involves multiple engineering disciplines. Even something as humble as a toaster might be the joint effort of software and hardware engineers. Assuming you still have the unabated curiosity to know how stuff works, this book will try to fill any knowledge gaps you might run into. Actually, this book is a brain dump of what I have picked up over the past 15+ years. Some of this knowledge has been learned the hard way, which is passively through insomnia and hair loss. And it is my best wishes that you don t have to go through the same ordeals I endured. In addition to the traditional design approach, the semiconductor industry s latest juggernaut has made SOPC (System on Programmable Chips) a viable option both technologically and financially. It is a trail blazed by many newly designed embedded systems, which this book explores in depth. Lastly, this book will serve you better if you ve taken some college-level courses in CS or EE, or maybe a little bit of both. Basic knowledge in C/C++ and FPGA can help you sail through this book more smoothly. Thank you for your faith in my book! Changyi Gu 02/14/2016 in San Diego, CA xxi