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

 

A

B

C

D

 

E

F

 

G

 

H PXIRQ0 PXIRQ1 PXIRQ2 PXIRQ3

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

PCI slot 1

shared

shared

shared

shared

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

PCI slot 2

shared

shared

shared

shared

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

PCI slot 3

 

 

 

shared

shared

shared

shared

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

PCI slot 4

 

 

 

shared

shared

shared

shared

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

PCI slot 5

shared

shared

shared

shared

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Onbd. USB contr. HC0

shared

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Onbd. USB contr. HC1

used

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Onbd. USB contr. HC2

used —

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Onbd. USB contr. HC3

shared

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Onbd. USB 2.0 contr.

 

 

shared

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Onbd. LAN

 

shared

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Onbd. VGA controller

shared

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Onbd. RAID controller

 

 

 

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.

ASUS PSCH-L motherboard

2-15