AMD-761 Datasheet, PDF (141/264 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
Bit Definitions (Continued)
AGP/PCI Status, I/O Base and Limit (Dev1:0x1C)
Bit Name
Function
7–4 IO_Base[15:12] I/O Base (Write)
The upper writable 4 bits define the bottom address of an address range that is used by
the bridge to determine when to forward I/O transactions from one interface to the other.
3–0 IO_Base_R
I/O Base (Read)
The lower read-only 4 bits define the bottom address of an address range that is used by
the bridge to determine when to forward I/O transactions from one interface to the other.
0x1 indicates that 32-bit I/O address decoding is available.
Programming Notes
Chapter 2
AMD-761™ System Controller Programmer’s Interface
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