
214
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
0x0x0x0Ch
PCI Latency Timer and
Header Type
31:24
Reserved
00h
r
23:16
Header_Type
00h
r
15:8
Lat_Timer
20h
B
7:0
Reserved
00h
r
0x0x0x10h
BAR0:AGP Virtual Address Space
31:25
AGP Base Address Register 0
GART AGP Aperture Address
xxxx_xxxb
A
24:4
Base Address Low
0b 00_000h
r
Always 0 = 32 Mbytes
minimum
3
Flags BAR0 mem as Prefetchable
1b
r
PCI specification
2:1
BAR0 Type mem as 32 bits
00b
r
PCI specification
0
Flags BAR0 as MEMORY
Address Space
0b
r
PCI specification
0x0x0x14h
BAR1:GART Memory Mapped
Register Base
31:12
GART Memory Mapped Base
Address Register
Settable portion of Address
xxxx_xh
A
11:4
GART Memory Mapped Base
Address Register Low, hardwired
to force 4 Kbytes
00h
r
3
BAR1 mem Prefetchable
1b
r
PCI specification
2:1
BAR1 Type mem as 32 bits
00b
r
PCI specification
0
Flags BAR1 as MEMORY
0b
r
PCI specification
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