Freescale Semiconductor TWR-MCF52259-Ethenet User Manual page 99

How Does the Host Know a Device's Requirements?
Device Descriptor
Since the device descriptor
represents the entire device,
there can be only one per
device. This descriptor specifies
basic information such as: USB
version supported, maximum
packet size, the number of
configurations, and vendor and
product ID info.
//------------------------------------------------------------
// Sample Standard Device Descriptor Type
// Definition Fields
//------------------------------------------------------------
Length (18 bytes)
Descriptor Type (DEVICE)
USB Spec Release Number (0200h)
Device class (hub type...Human Interface defined in
other descriptor, CDC described here)
TM
Device Sub-class (00h)
Device protocol (00h)
Maximum Packet size (64 bytes – max for the
Vendor ID (ID assigned by USB IF)
Product ID (ID assigned by product manufacturer)
Device release number (revision code of device)
Manufacturer (ABC Corp)
Product (string identifier)
Serial Number (1234)
Number of configurations (1 or more configurations
endpoint)
can follow)