USB Design by Example
`
`A Practical Guide to Building //0 Devices
`John Hyde
`
`Intel
`University
`Press
`
`The PC Platform
`
`Designers' Choice
`
`USB Design By Example. Buttons and Lights
`
`B ="real" buttons
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`Exhibit 2056 - Page 01 of 04
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`Exhibit 2056 - Page 01 of 04
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`

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`Publisher: Robert Ipsen (Wiley), Rich Bowles (Intel)
`Acquisitions Editor: Cary Sullivan
`Editor: Marcia Petty
`Assistant Editor: David Spencer
`Managing Editor: Frank Grazioli
`New Media, Associate Editor: Mike Sosa
`Text Design & Composition: Marianne Phelps
`Graphic Art: Jerry Heideman (illustrations), Dan Mandish (cover)
`
`Copyright © 1999 Intel Corporation. All rights reserved.
`Published by John Wiley & Sons, Inc. Published simultaneously in Canada.
`
`No part of this publication may be reproduced, stored in a retrieval system or transmitted in any form or by
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`under Sections 107 or 108 of the 1976 United States Copyright Act, without either the prior written
`permission of the Publisher, or authorization through payment of the appropriate per-copy fee to the
`Copyright Clearance Center, 222 Rosewood Drive, Danvers, MA 01923, (978) 750-8400, fax (978)
`750-4744. Requests to the Publisher for permission should be addressed to the Permissions Department, John
`Wiley & Sons, Inc., 605 Third Avenue, New York, NY 10158-0012, (212) 850-6011, fax (212) 850-6008,
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`This publication is designed to provide accurate and authoritative information in regard to the subject matter
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`All information provided in this publication is provided "as is" with no warranties, express or implied,
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`
`This book is printed on acid-free paper. 0
`
`Library of Congress Cataloging in Publication Data:
`
`Hyde, John, 1952-
`USB design by example : a practical guide to building 10 devices / John Hyde.
`p. cm.
`Includes index.
`ISBN 0-471-37048-7
`1. USB (Computer bus) 2. Computer input-output equipment—Design and construction. 1. Title.
`TK7895.B87H93 1999
`004.64—dc21 (cid:9)
`
`99-35865
`CIP
`
`Printed in the United States of America
`
`10 9 8 7 6 5 4 3 2 1
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`Exhibit 2056 - Page 02 of 04
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`

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`62 (cid:9)
`
`USB Design by Example
`
`The density and complexity of the integrated I/O capability also vary greatly. It
`is best to design your I/O device first, and then look for the best match of features
`from a list of available components (see Appendix A for a selection guide).
`One device we'll use in several examples is the EZ-USB component from
`Anchor Chips (Figure 3-12). This component has a unique implementation in
`that the program memory of the protocol controller is RAM. On power-up, an
`intelligent SIE holds the protocol controller in reset. The SIE understands the
`enumeration process and can complete the process without help from the
`protocol controller. The device driver specified by the EZ-USB device descriptor
`knows how to do one thing: Download a program into the program RAM and
`remove the reset from the protocol controller. We thus soft-load a program into
`the I/O device!
`The EZ-USB component then programmatically detaches itself from the hub and
`reattaches itself with its newly loaded personality. Anchor Chips calls this
`process "renumeration," and it means that the device doesn't have to be built
`with a mask ROM, be programmed, or even be flashed. If you think that your
`I/0 device program may change after it ships to users, then software update is as
`easy as providing a new file on the PC host. No product to recall. No new parts
`or EPROMs to manufacture and supply. Just ask your users to download an
`update from the Internet!
`
`USB —
`
`XCVR
`
`Serial
`Interface
`Engine
`
`RAM
`
`8051
`
`Reset
`
`INT
`
`Counter
`Timer
`
`UART
`
`I/O
`Ports
`
`120
`
`Figure 3-12. EZ-USB component from Anchor Chips
`
`Local Expansion
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`Exhibit 2056 - Page 03 of 04
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`Exhibit 2056 - Page 03 of 04
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`

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`Chapter 3 The Enumeration Process (cid:9)
`
`63
`
`The EZ-USB component is a little more expensive than ROM or EPROM parts
`because its program in RAM means that the die is larger. For low- and medium-
`volume projects, however, use of this component could be a cheaper solution
`overall. Anchor Chips has compatible ROM parts for high volume—these are
`not downloadable, but you are not penalized for designing a successful product
`(the part has a lower unit cost but fewer features). Because the many examples in
`this book have different personalities, I will use the Anchor Chips EZ-USB
`component for these examples.
`
`COMPLEX I/O DEVICE
`
`This section expands on the minimal descriptors described earlier in the chapter.
`Edit the descriptors slowly so you can appreciate their building-block nature.
`First we'll add a Strings descriptor. This has a variable length header followed
`by variable length string entries (Figure 3-13). The header consists of a length
`and type entry (2N+2 and 3) followed by an array (N) of LanguageIdentifiers.
`Each string entry consists of a length and type entry followed by a unicode
`string. A unicode string uses a word to represent each character and is not
`NULL-terminated. For more information on unicode, please refer to The
`Unicode Standard, Worldwide Character Encoding, produced by The Unicode
`Consortium and published by Addison-Wesley, Reading, Massachusetts, U.S.
`
`String
`Language Identifier(0) (cid:9)
`Length=2N+2 (cid:9)
`UNICODE Char(0) (cid:9)
`1141 Length=2A+2 (cid:9)
`UNIUUUt unartu)
`e LLennjt=e in_1::+z e (cid:9)
`
`lir)
`U
`N ILAJLJC Urldf (U)
`type=s
`UINIUUUL unarm
`ngm=a)+z (cid:9)
`Le
`I Denotes a repeated field
`
`Type=3
`Type=3
`I yi yppe:
`
`
`Language Identifier( (N)
`UNICODE Char(A)
`UNIUUUt -L.nar(tt)
`1-11\11UVIJC
`uNiuuut unar(u)
`
`Figure 3-13. Format of a strings descriptor
`
`For the examples here, I use a NULL in the high byte and an ASCII character in
`the low byte. The order in which the strings are declared will define their
`INDEX—the indexes start from 1 because a 0 is used to define "no string." We
`can now use useful, human-readable strings in our I/O device and go back to our
`descriptors and back-fill the string index entries. These strings are helpful during
`the debug and enumeration phases because they allow Windows to better identify
`the device (or it uses "unknown device," which is not very helpful).
`
`Exhibit 2056 - Page 04 of 04
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`Exhibit 2056 - Page 04 of 04
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`(cid:9)
`(cid:9)
`(cid:9)
`(cid:9)