Adding PCI cards

PCI bus interrupts - Selecting correct PCI slot

To achieve optimum stability, performance and compatibility, avoid the multiple use of i ISA IRQs or PCI IRQ Lines (IRQ sharing). Should IRQ sharing be unavoidable, then all

involved devices and their drivers must support IRQ sharing.

PCI IRQ Lines connect AGP slots, PCI slots and onboard components to the interrupt controller. PCI IRQ Lines are permanently wired on the mainboard.

Which ISA IRQs are assigned to the PCI IRQ Lines is normally automatically specified by the BIOS (see description in "BIOS Setup").

Monofunctional expansions cards:

Standard AGP and PCI expansion cards require a maximum of one interrupt, which is called the PCI interrupt INT A. Expansion cards that do not require an interrupt can be installed in any desired slot.

Multifunctional expansion cards or expansion cards with integrated PCI-PCI bridge:

These expansion cards require up to four PCI interrupts: INT A, INT B, INT C, INT D. How many and which of these interrupts are used is specified in the documentation provided with the card.

The assignment of the PCI interrupts to the PCI IRQ Lines is shown in the following table:

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Controller or slot INT

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

On board controller

 

 

 

 

 

 

 

 

 

 

Mechanical slot

 

 

 

Chips

 

 

 

 

 

 

 

 

 

 

1

 

 

2

 

 

3

 

 

4

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

et

 

USB 1.1

 

 

USB 2.0

 

 

 

 

AC97

 

 

 

 

 

 

 

 

 

 

 

PCI slot

 

 

 

 

 

INT

 

 

 

 

 

 

 

 

 

 

 

IDE

 

 

Audio

 

Modem

 

 

LAN

 

 

AGP

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

LINE

 

1st

 

 

2nd

 

 

3rd

 

 

 

 

 

 

 

 

 

 

 

 

1

 

 

2

 

 

3

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

1 (A)

 

-

 

-

 

-

 

-

+

 

-

 

-

 

-

 

 

A

 

 

B

 

 

C

 

 

D

 

-

 

-

-

 

2 (B)

 

-

 

-

 

-

 

-

-

 

-

 

-

 

-

 

 

B

 

 

C

 

 

D

 

 

A

 

-

 

-

-

 

3 (C)

 

-

 

-

 

-

 

-

-

 

+

 

+

 

-

 

 

-

 

 

D

 

 

A

 

 

B

 

-

 

-

-

 

4 (D)

 

-

 

-

 

-

 

-

-

 

-

 

-

 

+

 

 

-

 

 

A

 

 

B

 

 

C

 

-

 

-

-

 

5 (E)

 

+

 

-

 

-

 

-

-

 

-

 

-

 

-

 

 

-

 

-

 

-

 

-

 

 

-

 

-

-

 

6 (F)

 

-

 

+

 

-

 

-

-

 

-

 

-

 

-

 

 

-

 

-

 

-

 

-

 

 

-

 

-

-

 

7 (G)

 

-

 

-

 

+

 

-

-

 

-

 

-

 

-

 

 

-

 

-

 

-

 

-

 

 

-

 

-

-

 

8 (H)

 

-

 

-

 

-

 

+

-

 

-

 

-

 

-

 

 

-

 

-

 

-

 

-

 

 

-

 

-

-

Use the first PCI slots that have a single PCI IRQ Line (no IRQ sharing). If you must use another PCI slot with IRQ sharing, check whether the expansion card properly supports IRQ sharing with the other devices on this PCI IRQ Line. The drivers of all cards and components on this PCI IRQ Line must also support IRQ sharing.

22 - English

A26361-D1961-Z120-1-7419, edition 2

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Fujitsu D1961 technical manual PCI bus interrupts Selecting correct PCI slot, Audio Modem, Monofunctional expansions cards