AMD

P R E L I M I N A R Y

 

 

ISA Plug and Play Register Set — The Am79C930 de- vice fully supports the ISA Plug and Play specification, revision 1.0a.

The Am79C930 device supports the Plug and Play Auto-configuration scheme. The Plug and Play

ADDRESS Auto-configuration Port, WRITE_DATA Auto-configuration Port, and READ_DATA Auto-con- figuration Port are all supported and are mapped into ISA I/O space as follows:

Am79C930 Device ISA Plug And Play Mode Supported Auto-Configuration Ports

Port Name

ISA (IEEE P996) I/O Address

Access

 

 

 

ADDRESS

0279h

Write only

WRITE_DATA

0A79h

Write only

READ_DATA

0203h – 03FFh (relocatable)

Read only

 

 

 

The location of the READ_DATA Auto-configuration port is only fixed within the range 0203h–03FFh. The exact location is determined by a write to the appropriate Plug and Play Auto-configuration port (Set READ_DATA Auto-configuration port).

The WRITE_DATA port and the READ_DATA port are not active until the Initiation Key has been sent to the Am79C930 device through the ADDRESS port. This be- havior conforms to the requirements of the Plug and Play specification.

The Am79C930 device implements the four Plug and Play configuration states: “Wait for Key,” “Sleep,” Isolation,” and “Config.”

All Plug and Play ports are 8 bits in width.

To fully support the Plug and Play mechanism, the fol- lowing additional register locations are defined within the Am79C930 device. Except for the Resource Data register, these registers are physically located within the BIU and are accessed indirectly, through setting the Plug and Play Port Address in the Plug and Play ADDRESS port (location I/O 0279h) and then by ac- cessing either the WRITE_DATA port or the READ_DATA port. The 80188 embedded core does not have access to the registers in the following table.

68

Am79C930

Page 68
Image 68
AMD Am79C930 manual Port Name ISA Ieee P996 I/O Address Access, Writedata, Readdata