
82815 GMCH
R
Datasheet
73
3.4.28.
ACAPID—AGP Capability Identifier Register
(Device 0: AGP Mode Only)
Address Offset:
Default Value:
Access:
Size:
A0–A3h
00200002h
Read-Only
32 bits
This register provides standard identifier for AGP capability.
31
24
Reserved
23
20
19
16
Major AGP Revision Number
Minor AGP Revision Number
15
8
Next Capability Pointer
7
0
AGP Capability ID
Bit
Description
31:24
Reserved.
23:20
Major AGP Revision Number.
These bits provide a major revision number of AGP specification that
this version of GMCH conforms. These bits are set to the value 0010b to indicate AGP Rev. 2.x.
19:16
Minor AGP Revision Number.
These bits provide a minor revision number of AGP specification that
this version of GMCH conforms. This number is hardwired to a value of “0000” (i.e., implying Rev x.0).
Together with major revision number this field identifies GMCH as an AGP REV 2.0 compliant device.
15:8
Next Capability Pointer.
AGP capability is the first and the last capability described via the capability
pointer mechanism; therefore, these bits are hardwired to 0s to indicate the end of the capability linked
list.
7:0
AGP Capability ID.
This field identifies the linked list item as containing AGP registers. This field has
the value 0000_0010b as assigned by the PCI SIG.