440EX/LX AT
MAINBOARD
AWARD BIOS SETUP
4-16
.Note: Most IRQ and DMA have its own purpose and they can not be assigned to
“PCI/ISA PnP”. For example, IRQ14 and IRQ15 is used by the onboard IDE
device. If you change the setting on IRQ14 and IRQ15, you will be unable to
connect the hard disk drive or CD ROM drive to the IDE interface on the
mainboard. So please make sure to check the IRQ and DMA assignment in
your system before you proceed to do the setting. For instance, if you do not
have the printer (IRQ7) or PS/2™ mouse (IRQ12) connected to your PC
system, you may assign IRQ7 and IRQ12 to “PCI/ISA PnP” so that you can
have more IRQs available for new add on cards.
PCI IDE IRQ Map To :
(only for off-board PCI IDE cards)
PCI-AUTO : The BIOS will scan and check the existing of the PCI IDE device and
identify the slot location where the PCI IDE locates, and then the system
BIOS will assign IRQ 14 for the primary IDE, and assign IRQ 15 for the
secondary IDE.
PCI-SLOT1 : In this field, you may tell the system BIOS to assign IRQ 14 for primary
to
IDE INT# and IRQ 15 for secondary IDE INT# on some certain PCI
PCI-SLOT4
slot. Under the normal condition, this selection is not recommended
because the IDE interfaces are already built on the mainboard.
ISA
: The BIOS will not assign any IRQ even when the system BIOS detects
the PCI IDE card on the PCI slot. The reason is because some certain
IDE cards will connect the IRQ 14 and 15 directly from ISA slot. (Such
ISA card is called as Legacy Header)
Used MEM base addr and
Used MEM Length
:
These fields are used for some special ISA legacy cards which will request memory
space below 1M address. Please refer to the user’s manual of your add on card to find
whether it will need such memory space. If your add on card does need to have such
memory space, please point out the memory address and its length of the legacy area in
this field. According to what is recorded in this field, BIOS will skip the UMB area that
is used by the legacy device to avoid the memory conflicting.
Note : No matter what is defined in the “Resources Controlled By” field (“Manual”
or “Auto”), the system BIOS will always assign IRQ resources to PCI devices from the
highest one first ( ie. IRQ15, 14, 13 …) while assign IRQ resources to ISA PnP devices
from the lowest one first ( ie. IRQ3,4,5 .. ).
