beautypg.com

Hardware setup, 3 assigning dma channels for isa cards, 4 isa cards and hardware monitor – Asus P2B-N User Manual

Page 31

background image

ASUS P2B-N User’s Manual

31

3. HARDWARE SETUP

Connectors

3. H/W SETUP

To simplify this process, this motherboard complies with the Plug and Play (PnP)
specification, which was developed to allow automatic system configuration when-
ever a PnP-compliant card is added to the system. For PnP cards, IRQs are assigned
automatically from those available.

If the system has both Legacy and PnP ISA cards installed, IRQs are
assigned to PnP cards from those not used by Legacy cards. The PCI and PnP con-
figuration of the BIOS setup utility can be used to indicate which IRQs are being
used by Legacy cards. For older Legacy cards that do not work with the BIOS, you
can contact your vendor for an ISA Configuration Utility.

An IRQ number is automatically assigned to PCI expansion cards after those used
by Legacy and PnP ISA cards. In the PCI bus design, the BIOS automatically as-
signs an IRQ to PCI cards that require an IRQ. To install a PCI card, you need to set
something called the INT (interrupt) assignment. Since all the PCI slots on this
motherboard use an INTA #, be sure that the jumpers on your PCI cards are set to
INT A.

3.7.3 Assigning DMA Channels for ISA Cards

Some ISA cards, both legacy and PnP, may also need to use a DMA (Direct Memory
Access) channel. DMA assignments for this motherboard are handled the same way
as the IRQ assignment process described earlier. You can select a DMA channel in
the PCI and PnP configuration section of the BIOS Setup utility.

IMPORTANT:

To avoid conflicts, reserve the necessary IRQs and DMAs for

legacy ISA cards (see 4.7 PNP and PCI Setup, choose Yes in IRQ xx Used By
ISA
and DMA x Used By ISA for those IRQs and DMAs you want to reserve).

3.7.4 ISA Cards and Hardware Monitor

The optional onboard hardware monitor uses the address 290H-297H, so legacy
ISA cards must not use this address or else conflicts will occur.