Functional Architecture
Intel® Server Boards SE7320SP2 and SE7525GP2
Revision
4.0
32
3.6.1.9 PCI
APIs
The system BIOS supports the INT 1Ah, AH = B1h functions as defined in the PCI BIOS
Specification. The system BIOS supports the real mode interfaces and does not support the
protected mode interfaces.
3.6.2
Split Option ROM
The BIOS supports the split option ROM algorithm per the PCI 3.0 specification.
3.6.3 Interrupt
Routing
The interrupt architecture accommodates both PC-compatible PIC mode and APIC mode
interrupts through use of the integrated I/O APICs in the Intel 6300ESB I/O controller.
3.6.3.1
Legacy Interrupt Routing
For PC-compatible mode, the Intel 6300ESB I/O controller provides two 82C59-compatible
interrupt controllers. The two controllers are cascaded with interrupt levels 8-15 entering on
level 2 of the primary interrupt controller (standard PC configuration). A single interrupt signal is
presented to the processors, to which only one processor will respond for servicing. The Intel
6300ESB I/O controller contains configuration registers that define which interrupt source
logically maps to I/O APIC INTx pins.
Interrupts, both PCI and IRQ types, are handled by the Intel 6300ESB I/O controller. The Intel
6300ESB I/O controller then translates these to the APIC bus. The numbers in the table below
indicate the Intel 6300ESB I/O controller PCI interrupt input pin to which the associated device
interrupt (INTA, INTB, INTC, INTD) is connected. The Intel 6300ESB I/O controller I/O APIC
exists on the I/O APIC bus with the processors.
Table 11. PCI Interrupt Routing/Sharing
Interrupt
INT A
INT B
INT C
INT D
Video PIRQB
Intel
®
82541 NIC
PIRQA
PCI Slot 3 (PCI 32b/33M)
PIRQF PIRQD PIRQB PIRQH
PCI Slot 5 (PCI 32b/33M)
PIRQE PIRQB PIRQH PIRQD
PCI Slot 2 (64b/66M)
PXIRQ1 PXIRQ2 PXIRQ3 PXIRQ0
PCI Slot 1 (64b/66M)
PXIRQ0 PXIRQ1
3.6.3.2
APIC Interrupt Routing
For APIC mode, interrupt architecture incorporates three Intel I/O APIC devices to manage and
broadcast interrupts to local APICs in each processor. The Intel I/O APICs monitor each
interrupt on each PCI device including PCI slots in addition to the ISA compatibility interrupts
IRQ(0-15).
When an interrupt occurs, a message corresponding to the interrupt is sent across a three-wire
serial interface to the local APICs. The APIC bus minimizes interrupt latency time for
Summary of Contents for SE7320SP2 - 800MHZ Ecc Ddr Xeon
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