STM32F100 Get Stuck

[christian2399]

Posted on February 25, 2016 at 22:39

Hello,

I am faced with a big problem.  We applied ESD (8KV) to our system and we noticed that the microcontroller (STM32F100RCT6) get stuck for ever. We use the Independant WatchDog and must be kicked properly.  When it gets stuck, there's no reset.  I toggle a LED when we kick the watchdog to help us to understand the problem...  In normal way, the led blinks correctly... until ESD freezes the microcontroller.   In this special case, I can see LED strong ON and blinking stopped completely... No reset occurs!We use internal HSI (8MHz).  The IWDG should use the LSI as main clock.Is that possible that the microcontroller could stop to work?  Internal clocks stop to run?  I want a confirmation of this please.  I noticed sometimes during ESD test, the system resets by itself...  When reset occurs, that means the IWDG works fine.   I'd like to fix this get stuck condition except power cycle it.Thank you very much!  I need your 5 cents on it.

[Tesla DeLorean]

Posted on February 25, 2016 at 23:08

Is that possible that the microcontroller could stop to work? 

ESD can cause latch-up to occur (ie the ESD causes a conduction path in the silicon that doesn't close after the event passes, becoming self sustaining until power is removed). Perhaps you want to provide some external protection?What is the state of the NRST pin? Can you reset it manually via a button attached to NRST? Or does it only respond to a power-cycle? Does it draw excessive power in this condition?

[krepa]

Posted on February 26, 2016 at 01:26

Which part of your system do you apply ESD to?