2-16
Chapter 2: Basic installation
Standard interrupt assignments
* These IRQs are usually available for ISA or PCI devices.
IRQ assignments for the system motherboard
When using a PCI card on shared slots, ensure that the drivers support “Share
IRQ” or that the cards do not need IRQ assignments; otherwise, conflicts will
arise between the two PCI groups, making the system unstable and the card
inoperable.
IRQ
Standard function
0
System Timer
1
Keyboard Controller
2
Programmable Interrupt
4
Communications Port (COM1)
6
Floppy Disk Controller
7
Printer Port (LPT1)*
8
System CMOS/Real Time Clock
9
ACPI mode when used*
10
IRQ Holder for PCI Steering*
11
IRQ Holder for PCI Steering*
12
PS/2 Compatible Mouse Port*
13
Numeric Data Processor
14
Primary IDE Channel*
A B
C D
E
F
G
H
PCI Slot 1
-
-
-
-
-
used
-
-
PCI Slot 2
-
-
-
-
-
-
used
-
PCI Express x16 slot shared
-
-
-
-
-
-
-
PCI Express x1 slot
-
shared
-
-
-
-
-
-
USB controller 1
-
-
-
-
-
-
-
shared
USB controller 2
-
-
-
shared
-
-
-
-
USB controller 3
-
-
shared
-
-
-
-
-
USB controller 4
shared
-
-
-
-
-
-
-
USB 2.0 controller
-
-
-
-
-
-
-
shared
LAN controller
-
-
-
-
shared
-
-
-
Audio controller
shared
-
-
-
-
-
-
-
