Chapter3 BIOS Setup
34
User’s Manual
PCI Latency Timer (PCI Clocks):
This option is used to control PCI latency timer period (follow PCI
clocks). Based on PCI specification 2.1 or later and PCI bus frequency in system, user can select different
timer to meet their PCI bus environment.
Primary Graphics Adapter:
The primary graphics adapter (i.e., the one that boots first) in a multi-display
configuration.
PCI VGA Palette Snoop:
Disabled
Æ
Data read and written by the CPU is only directed to the PCI VGA
device's palette registers. Enabled
Æ
Data read and written by the CPU is directed to the both the PCI VGA
device's palette registers and the ISA VGA device palette registers, permitting the palette registers of both
devices to be identical.
DMA Channel 0/1/3/5/6/7:
These items specify the bus that the system DMA (Direct Memory Access)
channel is used. The settings determine if AMIBIOS should remove a DMA from the available DMAs passed
to devices that are configurable by the system BIOS. The available DMA pool is determined by reading the
ESCD NVRAM. If more DMAs must be removed from the pool, the end user can reserve the DMA by
assigning an ISA/EISA setting to it.
IRQ3/4/5/7/9/10/11/14/15:
These items specify the bus where the specified IRQ line is used. The
settings determine if AMIBIOS should remove an IRQ from the pool of available IRQs passed to devices that
are configurable by the system BIOS. The available IRQ pool is determined by reading the ESCD NVRAM. If
more IRQs must be removed from the IRQ pool, the end user can use these settings to reserve the IRQ by
assigning an ISA/EISA setting to it. Onboard I/O is configures by AMIBIOS. All IRQs used by onboard I/O
are configured as PCI/PnP. If all IRQs are set to ISA/EISA, and IRQ14/15 are allocated to the onboard PCI
IDE, IRQ9 will still be available for PCI and PnP devices. Settings: ISA/EISA and PCI/PnP.
Reserved Memory Size:
This option specifies the size of the memory area reserved for legacy ISA
adapter cards. The settings are Disabled, 16K,32, or 64K. The default settings is Disabled.
Reserved Memory Address:
This option specifies the beginning address (in hex) of the reserved
memory area. The specified ROM memory area is reserved for use by legacy ISA adapter cards.
This option does not appear if the Reserved Memory Size option is set to Disabled.
The settings are C0000,C4000,C8000,CC000,D0000,D4000,D8000,or DC000.
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