Chapter 7
Recommended BIOS Settings
243
24081D—February 2002
AMD-761™ System Controller Software/BIOS Design Guide
Preliminary Information
Registers
-----
Bits
Description
Initialized/
Required
Value
Actual
Value
Key
fcn( )
Notes
0x0x1x90h
DDR CLK/CS Pad
Configuration
31:30
Reserved
00b
r
29:27
PSlewCLK
101b
B
Slowest 000b <-> 111b Fastest
CLK Rising Edge Slew Rate
26:24
NSlewCLK
101b
B
Slowest 000b <-> 111b Fastest
CLK Falling Edge Slew Rate
23:20
Reserved
0h
r
19:18
PDrvCLK
11b
B
Weakest 00b<->11b Strongest
CLK P Transistor Drv Strength
17:16
NDrvCLK
10b
B
Weakest 00b<->11b Strongest
CLK N Transistor Drv Strength
15:14
Reserved
00b
r
13:11
PSlewCS
101b
B
Slowest 000b <-> 111b Fastest
CS Rising Edge Slew Rate
10:8
NSlewCS
101b
B
Slowest 000b <-> 111b Fastest
CS Falling Edge Slew Rate
7:4
Reserved
0h
r
3:2
PDrvCS
11b
B
Weakest 00b<->11b Strongest
CS P Transistor Drv Strength
1:0
NDrvCS
10b
B
Weakest 00b<->11b Strongest
CS 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