![](http://datasheet.mmic.net.cn/300000/RIVA-128ZX_datasheet_16205325/RIVA-128ZX_80.png)
128-BIT 3D MULTIMEDIA ACCELERATOR
RIVA128ZX
80/85
Byte offsets 0x43 - 0x40
Writeable Subsystem Vendor ID (0x43 - 0x40)
Byte offsets 0x47 - 0x44
Capabilities Identifier Register (Offset = 0x47 - 0x44 = CAP_PTR)
0x43
0x42
0x41
0x40
31 30 29 28 27 26 25 24 23 22 21 20 19 18 17 16 15 14 13 12 11 10
9
8
7
6
5
4
3
2
1
0
S
S
Bits
Function
R W I
31:16
This SUBSYSTEM_ID field is aliased at 0x2F - 0x2E where it is read-only. It
may be modified by System BIOS for systems which do not have a ROM on
the RIVA128ZX data pins. This will ensure valid data before enumeration by
the operating system.
R W 0
15:0
This SUB_VENDOR_ID field is aliased at 0x2D - 0x2C where it is read-only. It
may be modified by System BIOS for systems which do not have a ROM on
the RIVA128ZX data pins. This will ensure valid data before enumeration by
the operating system.
R W 0
0x47
0x46
0x45
0x44
31 30 29 28 27 26 25 24 23 22 21 20 19 18 17 16 15 14 13 12 11 10
9
8
7
6
5
4
3
2
1
0
R
M
M
N
C
Bits
Function
R W I
31:24
Reserved = 0x00
R - 0
23:20
This field indicates the Major revision number of the AGP specification that
the RIVA128ZX conforms to.
= 0x01
R - 0x01
19:16
This field indicates the Minor revision number of the AGP specification that
the RIVA128ZX conforms to.
= 0x00
R - 0x00
15:8
NEXT_PTR contains the pointer to the next item in the capabilities list. This is
the last entry in the capabilities list, hence it contains a null pointer = 0x00.
R - 0x00
7:0
The CAP_ID field identifies the type of capability.
AGP = 0x02
R - 0x02