Chapter 7
Recommended BIOS Settings
215
24081D—February 2002
AMD-761™ System Controller Software/BIOS Design Guide
Preliminary Information
Registers
-----
Bits
Description
Initialized/
Required
Value
Actual
Value
Key
fcn( )
Notes
0x0x0x34h
AGP/PCI Capabilities Pointer
31:8
Reserved
000000h
r
7:0
Capabilities Pointer
A0h
r
AGP function pointer
First item in AGP
capabilities list
0x0x0x44h
Extended BIU Control
31:11
Reserved
000h
r
10:8
P0_WrDataDly
yyyb
r
7:4
Reserved
0b
r
3
P0_2BitPF
1b
B
Must be set for
AMD Athlon™ processor
2:0
Reserved
0b
B
Must be set by BIOS
0x0x0x48h
ECC Mode/Status
31:16
Reserved
0000h
r
15:14
SERR_Enable
xxb
B
00b = ECC/SERR Disabled
1xb = SERR on Multi_Bit Errors
x1b = SERR on Single Bit Errors
See SERR# 0x0x0x4[8]
13
Reserved
0b
r
12
ECC_Diag
0b
B
0 = Disable, 1= Enable
11:10
ECC_Mode
SPD # 11
xxb
B
SPD
00b = NO ECC or ECC Disabled
01b = Data Errors Reported
10b = Data Errors Corrected
for Memory and PCI /AGP
11b = Data Errors Corrected
and Memory Scrubbed
9:8
ECC_Status
00b
B
00b = No Error
x1b =MED Multi Bit Error
Detect
1xb =SED Single Bit Error
Detect
R/W/1C
7:4
ECC_CS_MED
yh
c
CS of first MED
3:0
ECC_CS_SED
yh
c
CS of first SED
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