Chapter 4: BIOS
107
South Bridge
The following USB information will display:
•
USB Module Version
•
USB Devices
Legacy USB Support
Select Enabled to support onboard legacy USB devices. Select Auto to disable legacy support
if there are no legacy USB devices present. Select Disable to have all USB devices available
for EFI applications only. The options are
Enabled,
Disabled and Auto.
XHCI Hand-Off
This is a work-around solution for operating systems that do not support XHCI (Extensible
Host Controller Interface) hand-off. The XHCI ownership change should be claimed by the
XHCI driver. The options are
Enabled
and Disabled.
Port 60/64 Emulation
Select Enabled for I/O port 60h/64h emulation support, which in turn, will provide complete
legacy USB keyboard support for the operating systems that do not support legacy USB
devices. The options are
Disabled
and Enabled.
PCIe PLL SSC
Select Enabled for PCH PCIe Spread Spectrum Clocking support, which will allow the BIOS
to monitor and attempt to reduce the level of electromagnetic interference caused by the
components whenever needed. The options are
Disabled
and Enabled.
Port 61h Bit-4 Emulation
Select Enabled for I/O Port 61h-Bit 4 emulation support to enhance system performance. The
options are
Disabled
and Enabled.