10 expansion slots, 1 configuring an expansion card, 2 standard interrupt assignments – Asus A7N8X-VM User Manual
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Chapter 1: Product Information
IRQ assignments for this motherboard
A
B
C
D
E
F
G
PCI slot 1
used
–
–
–
–
–
–
PCI slot 2
–
–
–
used
–
–
–
PCI slot 3
–
–
used
–
–
–
–
AGP slot
–
used
–
–
–
–
–
1.10
Expansion slots
The A7N8X-VM motherboard has three (3) PCI and one (1) Accelerated Graphics
Port (AGP). The following sub-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, 6 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 firmware.
1.10.2 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.