Page 46
Express-HLE
6.4
Interrupt Request (IRQ) Lines
PIC Mode
IRQ#
Typical Intterupt Resource
Connected to Pin
Available
0 Counter
0
N/A
No
1 Keyboard
controller
N/A
No
2
Cascade interrupt from slave PIC
N/A
No
3
Serial Port 2 (COM2) / PCI
IRQ3 via SERIRQ / PIRQ
Note (1)
4
Serial Port 1 (COM1) / PCI
IRQ4 via SERIRQ / PIRQ
Note (1)
5
Parallel Port 2 (LPT2)
IRQ5 via SERIRQ / PIRQ
Note (1)
6
Generic
IRQ6 via SERIRQ / PIRQ
No
7
Generic
IRQ7 via SERIRQ / PIRQ
Note (1)
8 Real-time
clock
N/A
No
9 Generic
N/A
Note
(1)
10
Serial Port 3 (COM3)
IRQ10 via SERIRQ / PIRQ
Note (1)
11
Serial Port 4 (COM4)
IRQ11 via SERIRQ / PIRQ
Note (1)
12
PS/2 Mouse
IRQ12 via SERIRQ / PIRQ
Note (1)
13 Math
Processor
N/A
No
14
Primary IDE controller
IRQ14 via SERIRQ / PIRQ
Note (1)
15
Secondary IDE controller
IRQ15 via SERIRQ / PIRQ
Note (1)
Note (1):
These IRQs can be used for PCI devices when onboard device is disabled.
APIC Mode
IRQ#
Typical Intterupt Resource
Connected to Pin
Available
0 Counter
0
N/A
No
1 Keyboard
controller
N/A
No
2
Cascade interrupt from slave PIC
N/A
No
3
Serial Port 2 (COM2)
IRQ3 via SERIRQ / PIRQ
Note (1)
4
Serial Port 1 (COM1
IRQ4 via SERIRQ / PIRQ
Note (1)
5 N/A
N/A
Note
(1)
6 N/A
N/A
Note
(1)
7 N/A
N/A
Note
(1)
8 Real-time
clock
N/A
No
9
PCI
IRQ9 via SERIRQ / PIRQ
Note (1)
10
Serial Port 3 (COM3)
IRQ10 via SERIRQ / PIRQ
Note (1)
11
Serial Port 4 (COM4)
IRQ11 via SERIRQ / PIRQ
Note (1)
12
PS/2 Mouse
IRQ12 via SERIRQ / PIRQ
Note (1)
13
Math Processor
N/A
Note (1)
14
Primary IDE controller
IRQ14 via SERIRQ / PIRQ
Note (1)
15
Secondary IDE controller
IRQ15 via SERIRQ / PIRQ
Note (1)
