I am working on iMX7D Soc power management. My product is battery operated and require efficient power management.
Let's say, initially I keep both - A7 and M4 is in RUN mode. M4 side i configured external interrupt as wake up source.
Keeping A7 operating in RUN mode, I put M4 core in STOP mode to observe the effect.
I have observed that putting M4 in STOP mode also puts A7 in STOP mode automatically.
If I give external interrupt trigger to M4, it will pull M4 out of STOP mode. In interrupt handler routine if I make M4 to RUN mode then A7 also start responding.
Why I am observing this type of behavior?
Why putting M4 in STOP mode, A7 stops responding?