Concepts
The General USB Process
How Does the Host Know a Device’s Requirements?
Software – General
Configuration
Descriptor
The configuration descriptor is a header to the interface descriptors. It specifies how this configuration of the device is powered, what the maximum power consumption is, and
how many interfaces there are. There can be more than one configuration descriptor (for example: if the device can switch between
//Sample Standard Configuration Descriptor Type
//Definition Fields
Length (9 bytes)
Descriptor Type (CONFIGURATION)
Total Length (total length in bytes of data returned) Number of Interfaces (number of interfaces present for this configuration)
Configuration Value (value used by the SetConfiguration request to select this configuration) Configuration (Index of String Descriptor describing this configuration)
Attributes (bus powered, self powered, remote wakeup)
Max Power (Maximum Power Consumption in 2mA units)
