User`s manual

70 System Resources

IRQ Lines APIC Mode

Table B-6: IRQ Lines APIC Mode

Note (1): These IRQs can be used for PCI devices when onboard

device is disabled. If IRQ is from ISA, user must reserve IRQ for ISA in

BIOS setup menu.

IRQ# Typical Interrupt Resource Connected to Pin Note

0 System Timer

3 Communications port (COM2)

IRQ3 via SERIRQ,

IRQ3 at ISA bus

Note (1)

4 Communications port (COM1)

IRQ4 via SERIRQ,

IRQ4 at ISA bus

Note (1)

Intel® 82801G (ICH7) SMBus

controller - 27DA

System CMOS /

Real-time clock

9 Microsoft ACPI-compliant system

10 Communications port (COM3)

IRQ10 via SERIRQ,

IRQ10 at ISA bus

Note (1)

11 Communications port (COM4)

IRQ11 via SERIRQ,

IRQ11 at ISA bus

Note (1)

13 Numeric data processor

14 Primary IDE controller

16 PCI standard PCI-to-PCI bridge