Pci Interrupt Routing Map - Intel D850GB Technical Product Specification

Intel Desktop Board D850GB Technical Product Specification
The ICH2 has eight programmable interrupt request (PIRQ) input signals. All PCI interrupt
sources either onboard or from a PCI add-in card connect to one of these PIRQ signals. Some PCI
interrupt sources are electrically tied together on the D850GB board and therefore share the same
interrupt. Table 16 shows an example of how the PIRQ signals are routed on the D850GB board.
For example, using Table 16 as a reference, assume an add-in card using INTA is plugged into PCI
bus connector 4. In PCI bus connector 4, INTA is connected to PIRQB, which is already
connected to the SMBus. The add-in card in PCI bus connector 4 now shares interrupts with these
onboard interrupt sources.
Table 16.

PCI Interrupt Routing Map

PCI Interrupt Source
AGP connector
ICH2 USB controller
SMBus controller
ICH2 USB controller
ICH2 Audio / Modem
ICH2 LAN
PCI Bus Connector 1 (J4E1)
PCI Bus Connector 2 (J4D1)
PCI Bus Connector 3 (J4C1)
PCI Bus Connector 4 (J4B1)
PCI Bus Connector 5 (J4A1)
NOTE
The ICH2 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.
48
ICH2 PIRQ Signal Name
PIRQF PIRQG PIRQH
INTA INTB INTC
INTD INTA INTB
INTC INTD INTA
INTB INTC INTD
INTA INTB INTC
PIRQB Other
INTB INTA to PIRQA
INTD to PIRQD
INTB
INTC to PIRQC
INTB
INTA to PIRQE
INTD
INTC
INTB
INTA
INTD