HP Vectra VL800, Техническое справочное руководство

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3 System Board
Assigned Device Interrupts
There are three major interrupt modes available:
PIC mode: This mode uses only the “Legacy” interrupt controllers, so that
only one processor can be supported.
Virtual wire mode: This mode is implemented with APIC controllers in the
ICH2 and used during boot time. The virtual wire mode allows the transition
to the “symmetric I/O mode”.
Symmetric I/O mode: This mode is implemented with APIC controllers in
the ICH2.
NOTE
In “PIC mode” and “virtual wire mode”, the PCI interrupts are routed to the
INT line. In the “symmetric I/O mode”, the PCI interrupts are routed to the
I/O APIC controllers and forwarded over an GTL bus to the processor.
PCI Interrupt Request Lines
PCI devices generate interrupt requests using up to four PCI interrupt
request lines (INTA#, INTB#, INTC#, and INTD#).
PCI interrupts can be shared; several devices can use the same interrupt.
However, optimal system performance is reached when minimizing the
sharing of interrupts. Refer to
page 74 for a table of the PCI device
interrupts.