USER MANUAL
CHAPTER 4
AMI UEFI BIOS SETUP
- 63 -
BIOS Setting
Description
Setting
Option
Effect
Legacy USB
Support
User can enable or
disable USB port.
Auto
Disable legacy support if no
USB devices are connected
Disable
Will keep USB devices
available only for EFI
applications.
Enable
Enable all the USB devices
XHCI Hand‐off
This is a workaround
for OSs without XHCI
hand‐ off support.
The XHCI ownership
Change should claim
by XHCI driver.
Disable
Disables this function
Enable
Enables this function
EHCI Hand‐off
This is a workaround
for OSs without ECHI
hand‐ off support.
The EHCI ownership
change should be
claimed by EHCI
driver.
*Disabled
Disables this function
Enable
Enables this function
USB Mass
Storage Driver
Support
User can Enable or
disable USB mass
storage driver
support.
Disable
Disables this function
Enable
Enables this function
USB Transfer
time‐ out
The time‐out value
for control, bulk, and
interrupt transfers.
1 Sec
5 Sec
10 Sec
*20 Sec
Depends on the time‐out
value
Device Reset
time‐ out
USB mass storage
device start unit
command time‐ out.
10 Sec
*20 Sec
30 Sec
40 Sec
Depends on the time‐out
value
Device power‐
up delay
Maximum time the
device will take
before it properly
reports itself to the
host controller.
Auto
Uses default value: for a root
port it is 100 ms, for a Hub
port the delay is taken from
Hub descriptor