Standard interrupt assignments

IRQ

Priority

Standard Function

0

1

System Timer

1

2

Keyboard Controller

2

–

Re-direct to IRQ#9

3

11

IRQ holder for PCI steering*

4

12

Communications Port (COM1)*

5

13

IRQ holder for PCI steering*

6

14

Floppy Disk Controller

7

15

Printer Port (LPT1)*

8

3

System CMOS/Real Time Clock

9

4

IRQ holder for PCI steering*

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

PCI slot 1

used

—

—

—

PCI slot 2

—

used

—

—

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.

2-14

Chapter 2: Basic installation