Technical information

16 Chapter 1
ISA IO/APIC IRQ Default Setting
PCI Interrupt Routing in PCI Mode
To program the PCI interrupt router is via PCI interrupt routing index and data registers. The index
register of PCI interrupts routing is C00h and the data register is C01h. The bit 7-4 of data register is
reserved. The value programming into data register is the mapped IRQ number. The value “0” is
represented that disables the mapping and IRQ2, 8 & 13 are reserved.
System IRQ Device
IRQ0 8254 Timer
IRQ1 Keyboard Controller
IRQ2 Cascade
IRQ3 Serial Port
IRQ4 Serial Port
IRQ5 USB
IRQ6 Floppy Controller
IRQ7 Parallel Port
IRQ8 RTC
IRQ9 Used for ACPI SCI
IRQ10
IRQ11
IRQ12 Mouse controller
IRQ13 System Interrupt/FERR
IRQ14 Primary IDE Controller
IRQ15 Secondary IDE Controller
Interrupt Routing
Device INTA INTB INTC INTD
USB -PCIIRQ15
RAGE_XL_A -PCIIRQ2
BCM5702 -PCIIRQ0
SCSI_LSI1020 -PCIIRQ13
PCI_SLOT1 -PCIIRQ1 -PCIIRQ2 -PCIIRQ3 -PCIIRQ4
PCI_SLOT2 -PCIIRQ4 -PCIIRQ3 -PCIIRQ2 -PCIIRQ1
PCI_SLOT3 -PCIIRQ5 -PCIIRQ6 -PCIIRQ7 -PCIIRQ8
PCI_SLOT4 -PCIIRQ8 -PCIIRQ7 -PCIIRQ6 -PCIIRQ5
PCI_SLOT5 -PCIIRQ9 -PCIIRQ10 -PCIIRQ11 -PCIIRQ12
PCI_SLOT6 -PCIIRQ12 -PCIIRQ11 -PCIIRQ10 -PCIIRQ9