Assigning Irqs For Expansion Cards - Asus INTEL TUSL2 User Manual

3. HARDWARE 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
0 1
1 2
2 N/A
3* 11
4* 12
5* 13
6 14
7* 15
8 3
9* 4
10* 5
11* 6
12* 7
13 8
14* 9
15* 10
*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:
PCI slot 1
PCI slot 2
PCI slot 3
PCI slot 4
PCI slot 5
PCI slot 6
Onboard VGA
Onboard USB controller HC0
Onboard USB controller HC1
AGP Pro
CNR LAN
CNR Audio/Modem
Onboard Promise
Onboard Audio
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.
Standard Function
System Timer
Keyboard Controller
Programmable Interrupt
Communications Port (COM2)
Communications Port (COM1)
Sound Card (sometimes LPT2)
Floppy Disk Controller
Printer Port (LPT1)
System CMOS/Real Time Clock
ACPI Mode when enabled
IRQ Holder for PCI Steering
IRQ Holder for PCI Steering
PS/2 Compatible Mouse Port
Numeric Data Processor
Primary IDE Channel
Secondary IDE Channel
A B C
— — —
— — —
— — —
— — —
— — —
— — used
shared — —
— — —
— — —
shared — —
— — —
— used —
— — —
— — —
ASUS TUSL2 User's Manual
D E F G
— — shared —
— — — shared
— — — —
— shared — —
— — shared —
— — — —
— — — —
used — — —
— — — —
— — — —
— shared — —
— — — —
— — — shared
— — shared —
H
—
—
shared
—
—
—
—
—
shared
—
—
—
—
—
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