Sirs

I have a board with 3 MCus (P89C51Rx2), each one has a serial communication with external device using a specific protocol and different serial port configuration (data bits, parity and baud rate).

I am needing exchange data between MCUs. I choose one to be a master and another ones as slaves.
The "internal" protocol is bidiretional.

Initially I think to use an external interrupt driven process to send/get data to master/slave.

For example, I think to use 2 wire communication between master /slave (Data and clock). The clock pin on slave is connected on INTx.

An additional idea to put on slaves is a wake up output pin. To alert the master that data between master/slave needs to be exchange. The wake up pin is connected to INT0 and INT1 on master (one for each slave)....

Is it the best solution or put I2C hardware interface is better to this framework ?

Other question related is how to share an RTC among MCus? Just one write on RTC. The others just read it to perform some process time based.


Regards

Jean Fernandes
Electronic Engineer
Brazil