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B. Interrupt Request Lines (IRQ)
Peripheral devices use interrupt request lines to notify CPU for the service
required. The following table shows the IRQ used by the devices.
Level
Function
IRQ 0
System timer
IRQ 1
Standard PS/2 Keyboard
IRQ 4
Communications Port (COM1)
IRQ 7
Intel(R) N10/ICH7 Family SMBus Controller - 27DA
IRQ 8
System CMOS/real time clock
IRQ 12
Microsoft PS/2 Mouse
IRQ 13
Numeric data processor
IRQ 18
Intel(R) N10/ICH7 Family USB Universal Host Controller - 27CA
IRQ 19
Intel(R) N10/ICH7 Family Serial ATA Storage Controller - 27C0
IRQ 22
High Definition Audio Controller
IRQ 23
Intel(R) N10/ICH7 Family USB Universal Host Controller - 27C8
IRQ 23
Intel(R) N10/ICH7 Family USB2 Enhanced Host Controller - 27CC
IRQ 4294967292
Realtek PCIe GBE Family Controller
IRQ 4294967293
Intel(R) Graphics Media Accelerator 3600 Series
IRQ 4294967294
Intel(R) N10/ICH7 Family PCI Express Root Port - 27D0
