My answer to How can one work with UART in Full Duplex Mode having simultaneous transmit and receive operations?
Answer by Shaunak Agastya Vyas:
Finally I solved the problem myself. I am able to get the communication working now. I am using FIFO Buffer of UART Module for that. My ARM1 is more critical than ARM2. As this is asynchronized communication, I fill the FIFO of ARM1 first with 8 bytes of data (that is my requirement). It takes around 0.56 ms (8*8/115200) to transmit and fill the Receiver FIFO of ARM2. After receiving data, I immediately store it in an array to get processed and flush the receive FIFO buffer. I have set the FIFO receive interrupt limit as 8 bytes. I am not using transmit interrupt at all. Rather I am flushing the transmit buffer before putting data in it. The ARM2 to ARM1 transmit happens the same way. So, FIFO has helped me to solve this and do the communication without setting anyone as master or disabling interrupts.
How can one work with UART in Full Duplex Mode having transmit and receive functionalities working simultaneously? – ResearchGate. Available from: [accessed Dec 18, 2016].