Register Description

R

3.6.11SBUSN1—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.

 

 

3.6.12SUBUSN1—Subordinate 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 software to allow mapping of configuration cycles to AGP.

Bit

Descriptions

 

 

7:0

Bus Number. Programmable. Default = 0.

 

 

86

Intel® 82845 MCH for SDR Datasheet

Page 86
Image 86
Intel 845 manual SBUSN1-Secondary Bus Number Register Device, SUBUSN1-Subordinate Bus Number Register Device