Usb 1.1 Device Controller; Usb Overview - Intel IXP45X Developer's Manual

8.0

USB 1.1 Device Controller

This chapter describes the Universal Serial Bus (USB) protocol and its implementation-
specific options for device controllers. These options include:
• Endpoint number, type, and function
• Interrupts to the Intel XScale
• A transmit/receive FIFO interface
A working knowledge of the USB standard is vital to effective use of this chapter. The
Universal Serial Bus Device Controller (UDC) of the Intel
Product Line of Network Processors is USB-compliant and supports all standard device
requests issued by the host. UDC operation summaries and quick reference tables are
provided.
Refer to the Universal Serial Bus Specification, revision 1.1, for a full description of the
USB protocol. The Universal Serial Bus Specification is available at the following Web
site:
http://www.usb.org.
Both this, USB-device interface and the USB-host interface can be used at the same
time. (For more information on the USB-host interface, see
on page
8.1

USB Overview

The UDC supports 16 endpoints and can operate half-duplex at a rate of 12 Mbps (as a
slave only, not as a host or hub controller). The UDC supports four device
configurations. Configurations 1, 2, and 3 each support two interfaces. This allows the
host to accommodate dynamic changes in the physical bus topology. A configuration is
a specific combination of USB resources available on the device. An interface is a
related set of endpoints that present a device feature or function to the host.
The UDC transmits serial information that contains layers of communication protocols.
Fields are the most basic protocol. UDC fields include:
• Sync
• Endpoint
• Cyclic Redundancy Check (CRC)
Fields are combined to produce packets.
A packet's function determines the combination and number of fields that make up the
packet. Packet types include:
• Token
• Data
® ®
Intel IXP45X and Intel IXP46X Product Line of Network Processors
Developer's Manual
278
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Intel IXP45X and Intel
352.)
®
IXP46X Product Line of Network Processors—USB 1.1 Device
®
Processor
• Packet identifier (PID)
• Frame number
• Start of frame
• Handshake
Controller
® ®
IXP45X and Intel IXP46X
"USB 2.0 Host Controller"
• Address
• Data
August 2006
Order Number: 306262-004US