2.5.3Interrupt assignments

Standard Interrupt assignments

IRQ

Priority

Standard function

0

1

System Timer

 

 

 

1

2

Keyboard Controller

 

 

 

2

-

Programmable Interrupt

 

 

 

3*

11

Communications Port (COM2)

 

 

 

4*

12

Communications Port (COM1)

 

 

 

5*

13

--

 

 

 

6

14

Floppy Disk Controller

 

 

 

7*

15

--

 

 

 

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.

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Chapter 2: Hardware information