AMD 8151 specifications Rev 3.03 - July, DevA, Bits, Description, AGP Capabilities Pointer

Models: 8151

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DevA:0x10

24888 Rev 3.03 - July 12, 2004

AMD-8151TMAGP Tunnel Data Sheet

AGP Device Graphic Virtual Memory Aperture Register

DevA:0x10

 

 

It is expected that the state of this register is copied into the host by software. This register controls no hard- ware in the IC.

Default: 0000 0000 0000 0008h

Attribute: See below.

Bits

Description

 

 

 

63:32

APBARHI. Read-write. Aperture base address register high. Note: bits[63:40] are required to be

 

programmed low; setting any of these bits high results in undefined behavior. Note: if

 

DevA:0x10[64BIT]=0, then these bits are read only, all zero.

 

 

31:22

APBARLO. Aperture base address register low. These bits are a combination of read-write and read-

 

only zero, based on the state of DevA:0xB4[APSIZE]; see that register for details.

 

 

 

21:4

Reserved.

 

3Read only. This bit is fixed at its default value to indicate that this register points prefetchable space.

264BIT: 64-bit pointer. Read; write once. 1=DevA:0x10 is a 64-bit pointer. 0=DevA:0x10 is a 32-bit pointer; bits[63:32] are reserved.

1:0

Read only. These bits are fixed at their default value to indicate that this register points memory space.

AGP Device Subsystem ID and Subsystem Vendor ID Register

DevA:0x2C

 

 

 

 

Default: 0000 0000h

Attribute: Read; write once.

 

Bits

Description

 

 

 

 

 

31:16

Subsystem ID. This field controls no hardware.

 

 

 

 

15:0

Subsystem vendor ID. This field controls no hardware.

 

 

 

 

 

AGP Capabilities Pointer

 

DevA:0x34

 

 

 

 

Default: 0000 00A0h

Attribute: Read only.

 

Bits

Description

 

 

 

 

 

 

31:8

Reserved.

 

 

 

 

7:0

Capabilities pointer. Specifies the offset in DevA:0 address space for the AGP capabilities block.

 

 

 

 

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AMD 8151 specifications Rev 3.03 - July, DevA, Bits, Description, AGP Capabilities Pointer