144
AMD-761™ System Controller Programmer’s Interface
Chapter 2
AMD-761™ System Controller Software/BIOS Design Guide
24081D—February 2002
Preliminary Information
GART Directory Base Address
Bar1 + 0x04
Register Description
Programming Notes
31
30
29
28
27
26
25
24
Bit
GART_Dir_Base_Addr
Reset
0
0
0
0
0
0
0
0
R/W
R/W
23
22
21
20
19
18
17
16
Bit
GART_Dir_Base_Addr
Reset
0
0
0
0
0
0
0
0
R/W
R/W
15
14
13
12
11
10
9
8
Bit
GART_Dir_Base_Addr
Reserved
Reset
0
0
0
0
0
0
0
0
R/W
R/W
R
7
6
5
4
3
2
1
0
Bit
Reserved
Reset
0
0
0
0
0
0
0
0
R/W
R
Bit Definitions
GART Directory Base Address (Bar1 + 0x04)
Bit
Name
Function
31–12
GART_Dir_Base
_Addr
GART Directory Base Address
These bits define the base address of the GART directory that is located in physical system
memory. These 20 bits correspond to the 20 most significant bits of the 32-bit GART
directory base address that is aligned on a 4-Kbyte page boundary. Twenty bits provide
4-Kbyte resolution, which is the minimum allowable size of the GART. A value other than 0
defines a valid base address.
11–0
Reserved
Reserved