> Does anyone know of how to setup
> the 8051 to operate in
> multiprocessor mode. I would
> like to operate a host system and
> 2 slaves. I know about sending
> out an address byte first and
> then the slaves will go into
> normal mode if the address matches.

That's all there is to it.

Initially all slaves should be in multiprocessor mode. That means they will only receive bytes if the 8th data bit is set. This normally an address byte.

All slaves receive the address byte. Each compares it to its own address. If it recognizes the byte as its address, it switches into normal (non-multiprocessor mode) so that all the following data bytes are received, even though the 8th data is NOT set. The other slaves that did not recognize their address continue in multiprocessor mode so the data bytes sent to the other processor are not received (since the 8th data bit is not set).

When the entire packet has been received by the destination slave, that slave returns to multiprocessor mode, waiting for another packet addressed to it.

Hope this helps...

Craig Steiner