Table 10. Pci Interrupt Routing Map - Intel SE7221BA1 Technical Manual

Entry server board technical product specification

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Table Of Contents

Table of Contents

Maps and Interrupts

•

INTA: By default, all add-in cards that require only one interrupt are in this category.

For almost all cards that require more than one interrupt, the first interrupt on the card

is also classified as INTA.

•

INTB: Generally, the second interrupt on add-in cards that require two or more

interrupts is classified as INTB. (This is not an absolute requirement.)

•

INTC and INTD: Generally, a third interrupt on add-in cards is classified as INTC and

a fourth interrupt is classified as INTD.

The ICH6-R has eight Programmable Interrupt Request (PIRQ) input signals. All PCI

Conventional interrupt sources either onboard or from a PCI Conventional add-in card connect

to one of these PIRQ signals. Some PCI Conventional interrupt sources are electrically tied

together on the board and therefore share the same interrupt. Table 10 shows an example of

how the PIRQ signals are routed.

For example, using Table 10 as a reference; assume an add-in card using INTA is plugged into

PCI Conventional bus connector 3. In PCI bus connector 3, INTA is connected to PIRQB, which

is already connected to the ICH6-R audio controller. The add-in card in PCI Conventional bus

connector 3 now shares an interrupt with the onboard interrupt source.

PCI Interrupt Source

IEEE-1394a controller

PCI bus connector 1

PCI bus connector 2

PCI bus connector 3

PCI bus connector 4

NOTE: In PIC mode, the ICH6-R can connect each PIRQ line internally to one of the IRQ signals (3, 4, 5,

6, 7, 9, 10, 11, 12, 14, and 15). Typically, a device that does not share a PIRQ line will have a unique

interrupt. However, in certain interrupt-constrained situations, it is possible for two or more of the PIRQ

lines to be connected to the same IRQ signal. Refer to Table 10 for the allocation of PIRQ lines to IRQ

signals in APIC mode.

PCI interrupt assignments to the USB ports, Serial ATA ports, and PCI Express* ports are dynamic.