Hi, i have imx8m mini evk and i have tested communication between A53 and M4 using RPMsg. I would like to know the methods that can be used to measure communication latency between A53 and M4?
Unfortunately, it could be possible, but it will not be an easy task.
If you go to the MU part of the reference manual, you can find that there is a flag that changes the state when the transmission between cores is finished. You will need to create a code in the M4 cortex that could detect when the flag changed.
The name of the register is Processor x Status Register (MUx_ASR).
However, in the code, you will need to play with the timers and interrupts to handle this operation. Unfortunately, this is out of our scope.
I apologize for the inconvenience this may give you.