ASUS P4SDR-VM motherboard user guide
2-13
Standard Interrupt Assignments
IRQ Priority Standard Function
0 1 System Timer
1 2 Keyboard Controller
2 N/A Programmable Interrupt
3* 11 Communications Port (COM2)
4* 12 Communications Port (COM1)
5* 13 Sound Card (sometimes LPT2)
6 14 Floppy Disk Controller
7* 15 Printer Port (LPT1)
8 3 System CMOS/Real Time Clock
9* 4 ACPI Mode when used
10* 5 IRQ Holder for PCI Steering
11* 6 IRQ Holder for PCI Steering
12* 7 PS/2 Compatible Mouse Port
13 8 Numeric Data Processor
14* 9 Primary IDE Channel
15* 10 Secondary IDE Channel
* These IRQs are usually available for ISA or PCI devices.
IRQ assignments for this motherboard
ABCD
PCI slot 1 — shared — —
PCI slot 2 — — shared —
PCI slot 3 — — — shared
Onboard USB controller HC0 — — — shared
Onboard USB controller HC1 — — — shared
Onboard audio — — shared —
When using PCI cards on shared slots, ensure that the drivers support
“Share IRQ” or that the cards do not need IRQ assignments.
Otherwise, conflicts will arise between the two PCI groups, making the
system unstable and the card inoperable.
2.6.3 PCI slots
There are three 32-bit PCI slots in this motherboard. The slots support PCI
cards such as a LAN card, SCSI card, USB card, and other cards that
comply with PCI specifications. The following figure shows a LAN card
installed on a PCI slot.