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:

 

Order 1

Order 2

Order 3

Order 4

PCI Slot 1

INT A#

INT B#

INTC#

INTD#

 

 

 

 

 

PCI Slot 2

INT B#

INTC#

INTD#

INT A#

 

 

 

 

 

PCI Slot 3

INTC#

INTD#

INT A#

INT B#

 

 

 

 

 

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