QG5000XSL9TH Datasheet, PDF (335/458 Pages) Intel Corporation – Intel 5000X Chipset Memory Controller Hub (MCH)

Functional Description
assumption is that the OS can reprogram the interrupt ID’s. Therefore, for directed
interrupts, the Intel 5000X chipset MCH will ensure that each interrupt is seen on both
FSBs.
Figure 5-14. XAPIC Address Encoding
31
20 19
12 11
4 3 2*
0
0xFEE
DID
EDID (not used) rh dm rsvd
DID: 8-bit destination ID. Software may assign each ID to any value.
EDID: Not used, is a reserved field in the Processor EHS.
rh: redirection bit (0=directed, 1=redirectable)
dm: destination mode (0=physical, 1=logical)
*: PCI/PCI Express transaction encoding. Copied to Ab5 on processor bus
The data fields of an interrupt transaction are defined by the processor and XAPIC
specifications. It is included here for reference.
Table 5-12. XAPIC Data Encoding
D[63:16]
x
D[15]
Trigger Mode
D[14]
Delivery Status
D[13:11]
x
D[10:8]
Delivery Mode
D[7:0]
Vector
5.6.2
XAPIC Destination Modes
The destination mode refers to how the processor interprets the destination field of the
interrupt message. There are two types of destination modes; physical destination
mode, and logical destination mode. The destination mode is selected by A[2] in PCI
Express and Ab[5] on the processor bus.
5.6.2.1
Physical Destination Mode (XAPIC)
In physical mode, the APIC ID is 8 bits, supporting up to 255 agents. Each processor
has a Local APIC ID Register where the lower 5 bits are initialized by hardware (Cluster
ID=ID[4:3], Bus Agent ID=ID[2:1], thread ID=ID[0]). The upper 3 bits default to 0’s
at system reset. These values can be modified by software. The Cluster ID is set by
address bits A[12:11] during reset. By default, the Intel 5000P Chipset will drive
A[12:11] to ‘00 for FSB0, and ‘01 for FSB1. The value driven on bit A[12] during reset
can be modified through the POC register on the Intel 5000X chipset MCH.
The Intel 5000P Chipset will not rely on the cluster ID or any other fields in the APIC ID
to route interrupts. The Intel 5000P Chipset will ensure the interrupt is seen on both
busses and the processor with the matching APIC ID will claim the interrupt.
Physical destination mode interrupts can be directed, broadcast, or redirected. An
XAPIC message with a destination field of all 1’s denotes a broadcast to all.
In a directed physical mode message the agent claims the interrupt if the upper 8 bits
of the destination field (DID field) matches the Local APIC ID of the processor or the
interrupt is a broadcast interrupt.
Redirected interrupts are redirected and converted to a directed interrupt by the
chipset as described in Section 5.6.3.2.
Intel^® 5000X Chipset Memory Controller Hub (MCH) Datasheet
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