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Recommended BIOS Settings
Chapter 7
AMD-761™ System Controller Software/BIOS Design Guide
24081D—February 2002
Preliminary Information
Registers
-----
Bits
Description
Initialized/
Required
Value
Actual
Value
Key
fcn( )
Notes
0x0x0x60h
BIU0 Status/Control
31
Probe enable for CPU0
1b
B
0=Disable, 1=Enable
30:28
Reserved
000b
B
27:25
Xca_Probe_Cnt
010b
B
24:22
Xca_RD_Cnt
110b
B
21:19
Xca_WR_Cnt
110b
B
18
AMD Athlon system bus halt
disconnect enable
0b
B
0=Disable 1=Enable
Refer to “Power
for details.
17
AMD Athlon system bus stop
grant disconnect enable
1b
B
0=Disable, 1=Enable
Refer to “Power
for details.
16:14
Probe limit
110b
B
0-7 = 1 to 8 probes
110b = 7 recommended
13:10
Ack limit
0000 = 1 un-acked command
0001 = 2.......
0011b
r
This field should be used to
set up SysAckLimit in
AMD Athlon™
(+1 to this value) (SYSCFG)
9
Bypass_ En
Super Bypass Enable
1b
B
0=Disable, 1=Enable
8:7
SysDC_Out_ delay
yyb
r
From init logic
6:3
SysDC_In_ delay
yyyyb
r
From init logic
2
WR2_RD
yb
r
From init logic
1:0
RD2_WR
yyb
r
From init logic
0x0x0x64h
BIU0 SIP
31
ClkFwd Offset
0b
B
0=Delay groups 1 and 3
1=No delays
30:0
RO from Init/SIP logic
yyyb
yy_yyyyh
r
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