8 expansion cards, 1 assigning irqs for expansion cards, Standard interrupt assignments – Asus Terminator K7 User Manual
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Chapter 3: Motherboard Information
In the future, you may need to install expansion cards. The
motherboard has two PCI expansion slots to support PCI cards. Refer
to 2.8 Install a PCI Expansion Card section when installing
expansion cards.
3.8.1
Assigning IRQs for Expansion Cards
Some expansion cards need an IRQ to operate. Generally, an IRQ
must be exclusively 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.
IMPORTANT: If using PCI cards on shared slots, make sure that the
drivers support “Share IRQ” or that the cards do not need IRQ
assignments. Conflicts arise between the two PCI groups that makes
the system unstable or cards inoperable.
The following table lists the default IRQ assignments for standard
PC devices. Use this table when configuring your system and for
resolving IRQ conflicts.
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 used
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.
3.8 Expansion Cards
WARNING!
Unplug the system power cord when adding or removing expansion
cards or other system components. Failure to do so may cause severe
damage to both the motherboard and expansion cards.