User manual

Chapter 3 BIOS Setup
- 26 - CPC-3813-MIL
 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 distributed. The ISA devices
claim to engross the interrupt. Only the plug and play ISA devices can be distributed
by the BIOS or the OS. And several PCI devices share one interrupt through the
distribution of BIOS or OS. The diagram below shows parts of the interrupt
distribution under X86 platform, but it does not show the interrupt source occupied by
the PCI devices.
Level Function
IRQ0 System Timer
IRQ1 Reserved
IRQ2 Reserved
IRQ3 COM#2
IRQ4 COM#1
IRQ5 Reserved
IRQ6 Standard floppy disk controller
IRQ7 Reserved
IRQ8 System CMOS/Real Time Clock
IRQ9 ACPI Compliant System
IRQ10 Reserved
IRQ11 Reserved
IRQ12 Reserved
IRQ13 Numeric data processor
IRQ14 Reserved
IRQ15 Reserved