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This structure describes information about a specific USB device
configuration. USB devices may support several different
configutations, in which different interfaces on the device may
behave in different ways.
The total length of data returned for this configuration. This
includes the combined length of all stuctures — USB_CONFIGURATION,
USB_INTERFACE, USB_ENDPOINT and any class- or vendor-specific
structures — returned as part of the configuration information.
The number of interfaces supported as part of this
This configuration's value, used when the USB system software
of a USB device driver requests this configuration.
Index of a string descriptor describing this configuration.
Eight bits of configuration characteristics. Bits 0..4 are
reserved and should be 0. If bit 5 is set to 1, this configuration
supports remote wakeup. If bit 6 is set to 1, then in this
configuration the USB device uses power both from the bus and from
an external source (e.g. battery or wall socket). The
MaxPowermember gives the amount of bus power required during
The amount of power required in this configuration when the USB
device is fully operational, expressed in units of 2 milliamps
(that is, a value of 50 represent power consumption of 100mA). This
member is used if the
bmAttributesmember indicates that the device requires bus
In Windows CE 3.0, the UHCI driver software always chooses the
first available configuration for a USB device, regardless of
whether that configuration is suitable for use on the bus due to
power limitations, bandwidth availability, etc.