Abit Vi7, User Manual

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3-20 Chapter 3
PCI/VGA Palette Snoop:
This item determines whether the MPEG ISA/VESA VGA cards can work with PCI/VGA or not.
[Enabled]:
MPEG ISA/VESA VGA cards work with PCI/VGA.
[Disabled]: MPEG ISA/VESA VGA cards do not work with PCI/VGA.
Allocate IRQ To Video:
This item assigns an IRQ for the VGA card installed.
[Enabled]:
Automatically assign an IRQ for the VGA card installed.
[Disabled]:
The IRQ that was previously occupied by the VGA card will be available for new device.
Allocate IRQ To USB:
This item assigns an IRQ for the USB device connected.
[Enabled]:
Automatically assign an IRQ for the USB device connected.
[Disabled]:
The IRQ that was previously occupied by the USB device connected will be available for
new device.
PCI Latency Timer(CLK):
This item controls how long each PCI device can hold the bus before another takes over. When set to
higher values, every PCI device can conduct transactions for a longer time and thus improve the effective
PCI bandwidth. For better PCI performance, you should set the item to higher values.
PIRQ_0 Use IRQ No. ~ PIRQ_3 Use IRQ No.:
This item specifies the IRQ number manually or automatically for the devices installed on PCI slots.
For the relations between the hardware layout of PIRQ (the signals from the VIA VT8237 chipset), INT#
(means PCI slot IRQ signals) and devices, please refer to the table below:
Signals AGP LAN PCI-1 PCI-2 PCI-3 PCI-4 PCI-5 SATA
PIRQ_0 Assignment INT A INT A INT A INT D INT C INT B INT A
PIRQ_1 Assignment INT B INT B INT A INT D INT C
PIRQ_2 Assignment INT C INT B INT A INT D
PIRQ_3 Assignment INT D INT C INT B INT A
PIRQ_4 Assignment INT E
PIRQ_5 Assignment INT F
PIRQ_6 Assignment INT G
PIRQ_7 Assignment INT H
NOTE:
•
PCI slot 1 shares IRQ signals with AGP slot, LAN, and SATA.
•
If you want to install two PCI cards into those PCI slots that share IRQ with one another at the same
time, you must make sure that your OS and PCI devices’ driver supports the IRQ sharing function.
VI7