Pci Interrupt Request Routing - MSI 645 Ultra MS-6547 Manual

Chapter 2

PCI Interrupt Request Routing

The IRQ, abbreviation of interrupt request line and pronounced I-R-Q,
are hardware lines over which devices can send interrupt signals to the
microprocessor. The PCI IRQ pins are typically connected to the PCI bus INT
A# ~ INT D# pins as follows:
PCI Slot 1
PCI Slot 2
PCI Slot 3
PCI Slot 4
PCI Slot 5
Order 1 Order 2
INT A# INT B#
INT B# INT C#
INT C# INT D#
INT D# INT A#
INT B# INT C#
2-22
Order 3 Order 4
INT C# INT D#
INT D# INT A#
INT A# INT B#
INT B# INT C#
INT D# INT A#