USB_HUB_DESCRIPTOR structure (usbspec.h)
The USB_HUB_DESCRIPTOR structure contains a hub descriptor. The members of this structure are described in the Universal Serial Bus 3.1 Specification available at USB Document Library. See section 10.15.2.1.
Syntax
typedef struct _USB_HUB_DESCRIPTOR {
UCHAR bDescriptorLength;
UCHAR bDescriptorType;
UCHAR bNumberOfPorts;
USHORT wHubCharacteristics;
UCHAR bPowerOnToPowerGood;
UCHAR bHubControlCurrent;
UCHAR bRemoveAndPowerMask[64];
} USB_HUB_DESCRIPTOR, *PUSB_HUB_DESCRIPTOR;
Members
bDescriptorLength
The length, in bytes, of the descriptor.
bDescriptorType
The descriptor type. For hub descriptors, this value should be 0x29.
bNumberOfPorts
The number of ports on the hub.
wHubCharacteristics
The hub characteristics. For more information about this member, see Universal Serial Bus Specification.
bPowerOnToPowerGood
The time, in 2-millisecond intervals, that it takes the device to turn on completely. For more information about this member, see Universal Serial Bus Specification.
bHubControlCurrent
The maximum current requirements, in milliamperes, of the controller component of the hub.
bRemoveAndPowerMask[64]
Not currently implemented. Do not use this member.
This member implements DeviceRemovable and PortPwrCtrlMask fields of the hub descriptor. For more information about these fields, see Universal Serial Bus Specification.
Requirements
| Requirement | Value |
|---|---|
| Header | usbspec.h (include Usbioctl.h) |