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10 expansion slots, 1 configuring an expansion card, Irq assignments for this motherboard – Asus A7N8X-VM/400 User Manual

Page 22: Standard interrupt assignments

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1-12

Chapter 1: Product introduction

IRQ assignments for this motherboard

A

B

C

D

PCI slot 1

used

PCI slot 2

used

PCI slot 3

used

AGP slot

used

1.10

Expansion slots

The motherboard has three PCI and one Accelerated Graphics Port (AGP) slots.
The following sections describe the slots and the expansion cards that they
support.

1.10.1 Configuring an expansion card

Some expansion cards need an IRQ to operate. Generally, an IRQ must be
exclusively assigned to one function at a time. In a standard design configuration,
16 IRQs are available but most are already in use.

Normally, six IRQs are free for expansion cards. Sometimes IRQs are “shared” by
more than one function; in this case, IRQ assignments are swapped automatically
or adjusted through the BIOS Setup.

Standard Interrupt Assignments

IRQ

Standard Function

0

System Timer

1

Keyboard Controller

2

Programmable Interrupt Controller

3*

USB Universal Host Controller

4*

Communications Port (COM1)

5*

Onboard Audio

6

Standard Floppy Disk Controller

7*

Printer Port (LPT1)

8

System CMOS/Real Time Clock

9*

Onboard LAN

10*

USB Universal Host Controller

11*

Onboard VGA

12*

PS/2 Compatible Mouse Port

13

Numeric Data Processor

14*

Ultra ATA Controller

15*

Secondary Ultra ATA Controller

*These IRQs are usually available for ISA or PCI devices.