Register Description
3.8.3
Indirect Memory Space Registers
3.8.3.1
Register Summary
To access the indirect memory space, an 8-bit value must be written to the index register, which is
a “pointer” (indirect) to a 32-bit memory location. The 32-bit value in the Window Register can
then be read.
Table 3-4. Indirect Memory Space Registers Summary
Address
Offset
Symbol
Full Name
Default
Attribute
00h
01h
03h
10h
11h
ID
APIC ID Register
00000000h
00178020h
00000001h
00010000h
00000000h
00010000h
00000000h
00000000h
RW, RO
RO
VS
Version Register
BCFG
Boot Configuration Register
Redirection Table Low DWord 0 Register
Redirection Table High DWord 0 Register
Redirection Table Low DWord 23 Register
Redirection Table High DWord 23 Register
Reserved.
RW, RO
RW, RO
RW, RO
RW, RO
RW, RO
RO
RDL[0]
RDH[0]
RDL[23]
RDH[23]
Reserved
3E
3F
40–FF
3.8.3.2
Offset 00h: ID—APIC ID Register
Offset:
Default Value: 00000000h
00h
Attribute: RW, RO
Size: 32 bits
The APIC ID serves as a physical name of the APIC. The APIC bus arbitration ID for the APIC is
derived from its I/OxAPIC ID. This register is reset to zero on power up reset.
Bits
Type
Reset
Description
31:28
27:24
RO
RW
0
0
Reserved.
I/OxAPIC ID (APICID): Software must program this value before using the
I/OxAPIC.
23:0
RO
0
Reserved.
3.8.3.3
Offset 01h: VS—Version Register
Offset:
Default Value: 00178020h
01h
Attribute: RO
Size: 32 bits
Contains information related to this I/OxAPIC for driver/ OS/software.
Bits
Type
Reset
Description
31:24
23:16
RO
RO
0
Reserved.
17h
Maximum Redirection Entries (MAX): This is the entry number of the
highest entry in the redirection table. It is equal to the number of interrupt
inputs minus one. This field is hardwired to 17h to indicate 24 interrupts.
Intel® 6702PXH 64-bit PCI Hub Datasheet
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INTEL [ INTEL ]
