Lamar Lo

About MC9S12XDT256 reset problem at power regulator 3.3V

Discussion created by Lamar Lo on Apr 7, 2011
Latest reply on Apr 7, 2011 by kef

Hi experts


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?