Frequently Asked Questions

Q: How is the PCI interrupt routing accomplished?

A:

PCI interrupt routing in PIC mode (82C59 mode)

The PCI interrupt router is programmed via the 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 and 13 are reserved.


PCI interrupt routing in APIC mode