Hello,

I use Mode 3 of UART for my multi-processor
system. It hasn't been a problem at all... ever.
But before stepping into that make sure
you read the bible chapters and the datasheets
of associated parts. Be carefull while setting
the baudrates of different parts.

One more thing. If you have one master communicating
with various slaves then your master might need
two UARTs (one to communicate with computer and
other one for the Muli-processor mode). One more
option is using the SPI mode for the inter processor
communication.

To test the Multi-processor mode I would suggest
starting with a simple communication between
two processors first using Mode 1 of UART.
Then gradually move towards mode 3. And then start
off with addressing. Once you are able to 'choose'
the slave processor using software... then add
other babies to your network. If you are not
comfortable with interrupts you are gonna have some problems in getting it to work... but you always
have the forum to ask questions.

Good luck !

regards
Ashish