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Recommended BIOS Settings
Chapter 7
AMD-761™ System Controller Software/BIOS Design Guide
24081D—February 2002
Preliminary Information
Memory Rules
1. Memory must be organized so that the largest banks occupy the lowest
addresses.
2. All memory registers must be initialized, even when they are 0 memory
registers do not default to 0.
3. Unbuffered memories can be configured two deep, registered
memories can be configured four deep. In all cases, unused memory
registers must be zeroed.
Registers
-----
Bits
Description
Initialized/
Required
Value
Actual
Value
Key
fcn( )
Notes
0x0x0xC8h
Memory Base Address
Register 2
31:23
Chip-Select Base 2
xxh xb
B
As 0x0x0xC0h above
22:16
Reserved
000b 0h
r
As 0x0x0xC0h above
15:7
Chip-Select Mask 2
xxh xb
B
As 0x0x0xC0h above
6:3
Reserved
0h
r
As 0x0x0xC0h above
2:1
Addr_Mode
xxb
B
As 0x0x0xC0h above
0
Enable/Disable Bank 2
xb
B
As 0x0x0xC0h above
0x0x0xCCh
Memory Base Address
Register 3
31:23
Chip-Select Base 3
xxh xb
B
As 0x0x0xC0h above
22:16
Reserved
000b 0h
r
As 0x0x0xC0h above
15:7
Chip-Select Mask 3
xxh xb
B
As 0x0x0xC0h above
6:3
Reserved
0h
r
As 0x0x0xC0h above
2:1
Addr_Mode
xxb
B
As 0x0x0xC0h above
0
Enable/Disable Bank 3
xb
B
As 0x0x0xC0h above
KEY:
B= Mandatory BIOS function
A= AGP setup by BIOS
c = Calculated/set by AMD-761™ internal logic
P= Power management setup by BIOS
o = Setup by OS or OS driver
F = Performance enhancement set by BIOS
r = Hardcoded and reserved
u = PCI operational user interface
E = Elective BIOS function