I got a problem, when I use power 5V to supply MCU that it works normally.
But I change power 5V to 3.3V, it always reset repeatly.
I don't know what happen?
I try to look for datasheet, it doesn't mention setting any register when you change the power voltage level.
And I try to close watchdog and low voltage reset register, it's not work.
So I confuse why it can work on power 5V, but 3.3V doesn't?
The debug mode show me the message
BDMSTS BDM register not correct or status mismatch.
A hardware reset might have occurred.
DBG Trigger occurred
So have the expert give my some suggestions, please?