Register Description
R
86 Intel® 82845 MCH for SDR Datasheet
3.6.11 SBUSN1—Secondary Bus Number Register (Device 1)
Offset: 19h
Default: 00h
Access: R/W
Size: 8 bits
This register identifies the bus number assigned to the second bus side of the “virtual” PCI-PCI
bridge i.e. to AGP. This number is programmed by the PCI configuration software to allow
mapping of configuration cycles to AGP.
Bit Descriptions
7:0 Bus Number. Programmable. Default = 00h.
3.6.12 SUBUSN1—Subordi nate Bus Number Register (Device 1)
Offset: 1Ah
Default: 00h
Access: R/W
Size: 8 bits
This register identifies the subordinate bus (if any) that resides at the level below AGP. This
number is programmed by the PCI configuration softwar e to allow mapping of configuration
cycles to AGP.
Bit Descriptions
7:0 Bus Number. Programmable. Default = 0.