We asked for the offical Dallas position again on 7/06/2004. This was their answer...
"Dallas Semiconductor/MAXIM is in the business of manufacturing 1-Wire slaves. In order to maintain the structure of the network (i.e. assign unique node addresses to each device), Dallas must be the clearinghouse for that as well as maintain architectural control to avoid a chaotic situation on the network.
Dallas' intellectual property in the 1-Wire product area is structured around the 1-Wire slave devices. Regarding 1-Wire masters, however, the user is free to implement those in a variety of ways.
At this time we have not yet authorized anyone outside of Dallas Semiconductor to create 1-Wire slave devices. If you wish to produce such a device, please contact me off-list to discuss your needs." (David Smiczek)"
Is it true that as long as you hang a Dallas 1-wire device on the micro it would be considered legal?
Answer: NO, this is not true.
Is it true that Dallas will never use 0xFFh as a family code and therefore
it might be a good choice for a micro slave device?
Answer: NO, this is not true.
Assuming that Dallas is not going to use 0xFFh family codes, would the idea of using a 1-wire serial number device from Dallas hooked to the slave and having the slave device respond on the 1-wire network to a family code of 0xFFh with the serial number from the 1-wire device be a way of keeping
unique serial numbers?
Answer: Not true.
Regards,
--Brian Hindman,
Dallas Semiconductor MAXIM.
So if you were thinking of doing any sort of commerical 1-wire slave device, check with Dallas first. There are NO legal slave devices out there currently...
July 28th 2004 update
We did some checking and this appears not to be totally true... it seems that pre 1995 Dallas filed a lawsuit with Brooktree and lost. Brooktree ended up with the rights to make slave devices... Brooktree was then sold to TI which now owns the rights. Which is why there are some TI chips that are very simular to 1-wire. However they don't appear to be 1-wire protocol compatible nor use serial numbers. So use care...
July 29th, 2004
Another interesting conversation about the definition of "slaves" can be found on the Dallas Web Disccusion Board.
http://discuss.dalsemi.com/index.php?showtopic=128