Pci Interrupt Request Routing - MSI MS-6378 ATX User 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/USB/AC97/RTL8100" IRQ pins are typically con-
nected to the PCI bus INTA#-INTD# pins as follows:
PCI Slot 1 INT A# INT B# INT C# INT D#
PCI Slot 2 INT B# INT C# INT D# INT A#
PCI Slot 3 INT C# INT D# INT A# INT B#
USB-1
USB-2
AC97
RTL8100 INT D#
PCI Slot 3 & AC97 shared.
USB & RTL8100 shared.
PCI Slot 1~3: Bus Master
Order 1 Order 2 Order 3 Order 4
INT D# INT A# INT B# INT C#
INT D# INT A# INT B# INT C#
INT C# INT D# INT A# INT B#
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