Chapter 3 BIOS Setup
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NET-1821VD2N
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 Reserved
IRQ3 COM#2
IRQ4 COM#1
IRQ5
Reserved
IRQ6
Reserved
IRQ7
Reserved
IRQ8
System CMOS/Real Time Clock
IRQ9 ACPI-Compliant
System
IRQ10
PCI Device (SMBUS)
IRQ11 ME
IRQ12 Mouse
IRQ13
Numeric data processor
IRQ14
Master IDE Channel
IRQ15
Slave IDE Channel
