User manual

Chapter 3 BIOS Setup
EC0-1815V2NAR - 45 -
 IRQ Assignment Table
There are 15 interrupt sources of the system. Some are occupied by the system
devices. Only the ones that are not occupied can be assigned to other devices. ISA
device requests exclusive use of its interrupt. Only the plug and play ISA devices can
be assigned by the UEFI or the OS. And several PCI devices share one interrupt,
which is assigned by UEFI or OS. Interrupt assignment of some devices of X86
platform is shown in the table below, but it does not show the interrupt source
occupied by the PCI devices.
Level Function
IRQ0 System Timer
IRQ1 PS2 Keyboard
IRQ2 Programmable Interrupt Controller
IRQ3 COM2
IRQ4 COM1
IRQ5 Reserved
IRQ6 Reserved
IRQ7 Reserved
IRQ8 System CMOS/Real Time Clock
IRQ9 ACPI-Compliant System
IRQ10 Reserved
IRQ11 COM3/4/5/6
IRQ12 Mouse
IRQ13 Numeric data processor
IRQ14 Master IDE Channel
IRQ15 Slave IDE Channel