Pci Interrupt Request Routing - MSI MS-6137 v5.X Manual

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:
Order 1
PCI Slot 1 INT A#
PCI Slot 2 INT B#
PCI Slot 3 INT C#
Order 2 Order 3
INT B# INT C#
INT C# INT D#
INT D# INT A#
2-25
Hardware Setup
Order 4
INT D#
INT A#
INT B#