Register Description

R

3.5.30ATTBASE—Aperture Translation Table Base Register (Device 0)

Address Offset:

B8–BBh

Default Value:

0000_0000h

Access:

R/W

Size:

32 bits

This register provides the starting address of the Graphics Aperture Translation Table Base located in the system memory. This value is used by the MCH Graphics Aperture address translation logic (including the GTLB logic) to obtain the appropriate address translation entry required during the translation of the aperture address into a corresponding physical system memory address. The ATTBASE register may be dynamically changed.

Note: The address provided via ATTBASE is 4 KB aligned.

Bit

Description

 

 

31:12

Aperture Translation Table Base (TTABLE). This field contains a pointer to the base of the

 

translation table used to map memory space addresses in the aperture range to addresses in

 

system memory.

 

Note: It should be modified only when the GTLB has been disabled.

 

 

11:0

Reserved.

 

 

70

Intel® 82845 MCH for SDR Datasheet

Page 70
Image 70
Intel 845 manual ATTBASE-Aperture Translation Table Base Register Device