Hardware setup, 2 assigning irqs for expansion cards, Standard interrupt assignments – Asus INTEL TUSL2 User Manual
Page 29: Interrupt request table for this motherboard, Asus tusl2 user’s manual 29, Expansion cards 3. h/w setup

ASUS TUSL2 User’s Manual
29
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.
Interrupt Request Table for this Motherboard
Interrupt requests are shared as shown by the following table:
A
B
C
D
E
F
G
H
PCI slot 1
—
—
—
—
—
shared
—
—
PCI slot 2
—
—
—
—
—
—
shared
—
PCI slot 3
—
—
—
—
—
—
—
shared
PCI slot 4
—
—
—
—
shared
—
—
—
PCI slot 5
—
—
—
—
—
shared
—
—
PCI slot 6
—
—
used
—
—
—
—
—
Onboard VGA
shared
—
—
—
—
—
—
—
Onboard USB controller HC0
—
—
—
used
—
—
—
—
Onboard USB controller HC1
—
—
—
—
—
—
—
shared
AGP Pro
shared
—
—
—
—
—
—
—
CNR LAN
—
—
—
—
shared
—
—
—
CNR Audio/Modem
—
used
—
—
—
—
—
—
Onboard Promise
—
—
—
—
—
—
shared
—
Onboard Audio
—
—
—
—
—
shared
—
—
IMPORTANT:
If using PCI cards on shared slots, make sure that the drivers sup-
port “Share IRQ” or that the cards do not need IRQ assignments. Conflicts will arise
between the two PCI groups that will make the system unstable or cards inoperable.