244
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
0x0x1x94h
DDR CMDB/CMDA Pad
Configuration
31:30
Reserved
00b
r
29:27
PSlewCMDB
101b
B
Slowest 000b <-> 111b Fastest
CMDB Rising Edge Slew Rate
26:24
NSlewCMDB
101b
B
Slowest 000b <-> 111b Fastest
CMDB Falling Edge Slew Rate
23:20
Reserved
0h
r
19:18
PDrvCMDB
11b
B
Weakest 00b<->11b Strongest
CMDB P Transistor Drv Strength
17:16
NDrvCMDB
10b
B
Weakest 00b<->11b Strongest
CMDB N Transistor Drv Strength
15:14
Reserved
00b
r
13:11
PSlewCMDA
101b
B
Slowest 000b <-> 111b Fastest
CMDA Rising Edge Slew Rate
10:8
NSlewCMDA
101b
B
Slowest 000b <-> 111b Fastest
CMDA Falling Edge Slew Rate
7:4
Reserved
0h
r
3:2
PDrvCMDA
11b
B
Weakest 00b<->11b Strongest
CMDA P Transistor Drv Strength
1:0
NDrvCMDA
10b
B
Weakest 00b<->11b Strongest
CMDA N Transistor Drv Strength
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