AGP Subsystem

Figure 7-1. GART Table Usage for 4k Pages

39

11

0

 

AGP address

Offset

 

 

 

 

12b

AGP address (39:12) - APBASE(39:12)

 

 

(If less than APBASE+Aperture)

 

 

 

 

24 Bit

24b

 

18b

+

 

GART Entry

 

(16b if256 MB

 

 

of GART space)

 

 

 

 

GART Table

 

 

 

 

36b Main Memory Address

Figure 7-2. GART Table Usage for 4 MB Pages

39

21

0

AGP address

 

Offset

 

 

 

22b

AGP address (39:22) - APBASE(39:22)

(If less than APBASE+Aperture)

13b (8b if 1 GB GART,

6b if 256 MB GART)

14 Bit

GART Entry

14b

+

GART Table

36b Main Memory Address

7-2

Intel® 460GX Chipset Software Developer’s Manual

Page 132
Image 132
Intel 460GX manual 12b, 24b, 22b, 14b