Hardware setup, 7 expansion cards, 1 expansion card installation procedure – Asus CUSL2-M User Manual
Page 27: 2 assigning irqs for expansion cards, Standard interrupt assignments
ASUS CUSL2-M User’s Manual
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3. HARDWARE SETUP
Expansion Cards
3. H/W SETUP
3.7 Expansion Cards
WARNING
!
Unplug your power supply when adding or removing expansion
cards or other system components. Failure to do so may cause severe damage to
both your motherboard and expansion cards (see 3.3 Hardware Setup Proce-
dure for more information).
3.7.1 Expansion Card Installation Procedure
1. Read the documentation for your expansion card and make any necessary hard-
ware or software settings for your expansion card, such as jumpers.
2. Remove your computer system’s cover and the bracket plate on the slot you
intend to use. Keep the bracket for possible future use.
3. Carefully align the card’s connectors and press firmly.
4. Secure the card on the slot with the screw you removed above.
5. Replace the computer system’s cover.
6. Set up the BIOS if necessary
(such as IRQ xx Used By ISA: Yes in PNP AND PCI SETUP)
7. Install the necessary software drivers for your expansion card.
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.