What we currently do on just about all our boards is to use the DS2409 as a
board level select with the AUX channel talking to a DS2433 (EEPROM). (Ala
Dallas idea) Its a fairly large capacity device which makes holding a number
of ID tag's possible. And helping keep the idea of 1 tag device per board.
This also allows more meaningful data descriptors to be held if desired.
(i.e.. manufacture data (Version, dates, etc)/installation data (location,
service dates, etc.) Though any EEPROM device would be a good candidate also
(larger space is better). The recent DS28E04S-100 also address the need for
physical board address values along with EEPROM. Which allows installation
addressing info to be added in the field.
The cost factor is trivial when considered against the needs for good record
device management. And since the devices can be field updated during
installation (good and bad, its is not a huge problem.). Device key being
the DS2409 ID or EEPROM. .I suppose ideally a system would scan for these
devices (EPROM,EEPROM, HUBS etc.) and build a table when found. Thus the
routing and device addresses for all parts are pre-known, for a fixed
Sr. Computer Scientist