Using a 9-bit UART

Question: I have an application that uses a 9-bit serial bus format (Multi-Drop Bus - MDB) to communicate between various modules. There are 8 data bits and 1 "flag" bit to tell whether the remaining 8 bits are address or data. Is there any way to do this with 8-bit UART in PsoC1? Could we possibly hijack the parity bit and use it as a settable flag?

 

Answer:

Since you can dynamically change the parity bit (none, even, odd) before sending a data word, you could use this bit for a flag. You would need to figure out ahead of time, based on the data word to be sent, which way to configure the parity bit.