AMD-761 Datasheet, PDF (239/264 Pages) Advanced Micro Devices – AMD-761-TM System Controller Software/BIOS Design Guide

24081D—February 2002
Preliminary Information
AMD-761™ System Controller Software/BIOS Design Guide
Registers
----
Bits
0x0x0xA0h
31:24
23:20
19:16
15:8
7:0
0x0x0xA4h
31:24
23:10
9
8:6
5
Description
AGP Capability Identifier
Reserved
Major_Rev
Minor_Rev
Next_Pointer
Cap_ID
AGP Status Register
Max_ReqQ_Depth
Reserved
SBA
Reserved
R4G
4
FW
3
Reserved
2:0
Rates
0x0x0xA8h AGP Command Register
31:10 Reserved
9
SBA_Ena
Sideband addressing enable
AGP_Ena
8
AGP operation enable
7:6
Reserved
5
Greater than 4G address
support
4
Fast_Writes
3
Reserved
2:0
AGP data transfer mode
Initialized/
Required
Value
Actual
Value
Key fcn( )
Notes
00h
r
2h
r
0h
r
00h
r
Null = Final item on list
02h
r
02h = AGP
0Fh
00b 000h
1b
000b
0b
yb
0b
111b
r
Max # AGP Command
Requests
r
r
Side Band Addressing
Supported
r
r
Fixed at 4 Gbytes Maximum
0x0x _{1 = Fast Write Support}
r 0B4
[7] ^{0 = Fast Write Not Supported}
r
r
AMD-761 system controller
supports 1x/2x/4x
0000_0h
00b
yb
yb
0b
0b
yb
0b
yyyb
r
Set by operating system
o
agent, not BIOS.
0 = Disable, 1 = Enable
Set by operating system
o
agent, not BIOS.
0 = Disable, 1 = Enable
r
r
0 = Disable, 1 = Enable
o
0x0x0
B4[7]
0=Disabled, 1=Enabled
r
o
001b=1x, 010b=2x,100b=4x
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
Chapter 7
Recommended BIOS Settings
227