AMD-761 Datasheet, PDF (256/264 Pages) Advanced Micro Devices – AMD-761-TM System Controller Software/BIOS Design Guide

Preliminary Information
AMD-761™ System Controller Software/BIOS Design Guide
24081D—February 2002
Registers
-----
Bits
Description
0x0x1x94h
DDR CMDB/CMDA Pad
Configuration
31:30 Reserved
29:27 PSlewCMDB
26:24
23:20
19:18
NSlewCMDB
Reserved
PDrvCMDB
17:16 NDrvCMDB
15:14 Reserved
13:11 PSlewCMDA
10:8 NSlewCMDA
7:4
Reserved
3:2
PDrvCMDA
1:0
NDrvCMDA
Initialized/
Required
Value
Actual
Value
Key
fcn( )
Notes
00b
r
101b
B
Slowest 000b <-> 111b Fastest
CMDB Rising Edge Slew Rate
Slowest 000b <-> 111b Fastest
101b
B
CMDB Falling Edge Slew Rate
0h
r
Weakest 00b<->11b Strongest
11b
B
CMDB P Transistor Drv Strength
10b
B
Weakest 00b<->11b Strongest
CMDB N Transistor Drv Strength
00b
r
Slowest 000b <-> 111b Fastest
101b
B
CMDA Rising Edge Slew Rate
Slowest 000b <-> 111b Fastest
101b
B
CMDA Falling Edge Slew Rate
0h
r
11b
B
Weakest 00b<->11b Strongest
CMDA P Transistor Drv Strength
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
244
Recommended BIOS Settings
Chapter 7