USB_HUB_DESCRIPTOR structure (usbspec.h)

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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)

See also

USB Structures

USB_HUB_INFORMATION