
24
AMD-761™ System Controller Programmer’s Interface
Chapter 2
AMD-761™ System Controller Software/BIOS Design Guide
24081D—February 2002
Preliminary Information
Programming Notes
Bit Definitions
Configuration Address Register Type 1 (I/O:0CF8)
Bit
Name
Function
31
Config_En
Configuration Enable
0 = PCI configuration cycles are not generated.
1 = Accesses to the Configuration Data and Address registers are converted to
configuration cycles on the PCI.
30–24
Reserved
Reserved
23—16
PCI_Bus_Num
PCI Bus Number
This bit field defines which PCI bus in the system is referenced with this address. The
AMD-761™ system controller logically implements two PCI buses. The main PCI bus
normally enumerates as bus 0 and the AGP bus enumerates as bus 1.
15—11
Dev_Num
Device Number
This bit field defines which device is accessed in the system on the target PCI bus. This field
is passed on directly to the AD wires undecoded.
10—8
Func_Num
Function Number
This bit field defines which function is accessed in a given device. This field is passed on
directly to the AD wires undecoded.
7—2
Reg_Num
Register Number
This bit field defines which specific PCI register is accessed in the device and function
specified above.
1—0
Reserved
Reserved