Chapter 2
AMD-761™ System Controller Programmer’s Interface
77
24081D—February 2002
AMD-761™ System Controller Software/BIOS Design Guide
Preliminary Information
PCI Top of Memory
Dev0:F0:0x9C
Register Description
This register is used to define the top of main system memory. It is used to compare the memory addresses of an external
PCI master to determine if it is in the range of the AMD-761™ system controller DRAM. If the address compares, then the
AMD-761 system controller responds to the bus master access with DEVSEL# assertion.
31
30
29
28
27
26
25
24
Bit
PCI_Mem_Top
Reset
1
0
0
0
0
0
0
0
R/W
R/W
23
22
21
20
19
18
17
16
Bit
Reserved
Reset
0
0
0
0
0
0
0
0
R/W
R
15
14
13
12
11
10
9
8
Bit
Reserved
Reset
0
0
0
0
0
0
0
0
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