Chapter 4 Software Development
page 4-3
4-1-2. Specification Documents
USB specifications have been established by the USB Implementers Forum. These and other
materials are available on the World Wide Web at the following URLs.
Forum top page http://www.usb.org/developers/
Developers section http://www.usb.org/developers/
Developer documentation http://www.usb.org/developers/docs.html
Device classes http://www.usb.org/developers/devclass.html
Compliance testing http://www.usb.org/developers/complian.html
The USB Implementers Forum augments the core specifications, the document specifying
characteristics shared by all USB devices, with separate Universal Serial Bus Device Class
Specifications for specific device types.
4-1-3. Core Specifications
This document covers common characteristics of host controllers, hubs, devices, and transmission
pathways. Specific areas include an overview of USB communications, functionality, and bus
drivers; physical and electrical specifications for connectors, transmission pathways, and other
components; and the standard command-response device requests that all USB devices must support.
The current version number is 1.1.1
n
Note
n
Note: Version 1.1 superseded version 1.0 in October 1998. The older version is still
available on the World Wide Web. Apart from such additions as InterruptOut transfers,
most changes involve removing ambiguities in the older version. The electrical
specifications in Chapter 7 now provide more detail. The protocol layer specifications
in Chapter 8 add descriptions of STALL operation for the default control pipe and of
the Data stage of control transfers. The device framework specifications in Chapter 9
add descriptions of state processing for request errors. The hub specifications in
Chapter 11 have been completely rewritten.
Chapter 1 Introduction Objectives and target audience for USB specifications
Chapter 2 Terms and
Abbreviations
Definitions of key terms used
Chapter 3 Background Design goals and requirements addressed
Chapter 4 Architectural Overview Overview of USB architecture and key concepts
Chapter 8 Protocol Layer Packet definitions and detailed descriptions of
transaction formats for error detection and recovery,
etc.
Chapter 9 UBS Device Framework Detailed descriptions of device states, device requests,
1
Version 1.1 superseded version 1.0 in October 1998. The older version is still available on the World
Wide Web. Apart from such additions as InterruptOut transfers, most changes involve removing
ambiguities in the older version. The electrical specifications in Chapter 7 now provide more detail.
The protocol layer specifications in Chapter 8 add descriptions of STALL operation for the default
control pipe and of the Data stage of control transfers. The device framework specifications in
Chapter 9 add descriptions of state processing for request errors. The hub specifications in Chapter
11 have been completely rewritten.