AMD-761 datasheet(36/264 Pages) AMD

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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

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

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

This bit field defines which specific PCI register is accessed in the device and function

specified above.

1—0

Reserved

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