Hardware setup, 2 assigning irqs for expansion cards, Standard interrupt assignments – Asus TUWE-M User Manual
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ASUS TUWE-M User’s Manual
3. HARDWARE SETUP
Expansion Cards
3. H/W SETUP
3.7.2 Assigning IRQs for Expansion Cards
Some expansion cards need an IRQ to operate. Generally, an IRQ must be exclu-
sively assigned to one use. In a standard design, there are 16 IRQs available but
most of them are already in use, leaving 6 IRQs free for expansion cards. If your
motherboard has PCI audio onboard, an additional IRQ will be used. If your moth-
erboard also has MIDI enabled, another IRQ will be used, leaving 4 IRQs free.
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 enabled
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.