Asus MAXIMUS VI IMPACT - Manual (Page 122)

3-38 Chapter 3: BIOS setup
Chapter 3
3.6.5 USB Configuration
The items in this menu allow you to change the USB-related features.
The USB Devices item shows the auto-detected values. If no USB device is detected, the
item shows None.
Legacy USB Support [Enabled]
[Enabled] Enables the support for USB devices on legacy operating systems (OS).
[Disabled] The USB devices can be used only for the BIOS setup program. It cannot
be recognized in boot devices list.
[Auto] Allows the system to detect the presence of USB devices at startup. If
detected, the USB controller legacy mode is enabled. If no USB device is
detected, the legacy USB support is disabled.
Intel xHCI Mode [Smart Auto]
[Auto] Keeps the last operation of xHCI controller in OS during bootup.
[Smart Auto] Enables the operation of xHCI controller.
[Enabled] Enables the xHCI controller.
[Disabled] Disables the xHCI controller.
EHCI Hand-off [Disabled]
[Enabled] Enables the support for operating systems without an EHCI hand-off
feature.
[Disabled] Disables the EHCI Hand-off support.