Hi, we have perform a series of environment test for STM32H533, including thermal cycle and vibration test.
Durting vibration test, DUTs are powered off, while under thermal cycle test, DUT is powered on.
After the test, all application part still function as expected, including UART, ADC, basic IO...etc. However, we've found that three, out of six, DUTs can NOT be accessed through debug interface SWD.
Moreover, there are few things abnormal,
- nRst pin is about 3V, even through VDD is 3.3V
- ST-Link can NOT drive nRST pin to 0V, only 1.5V to 2V.
- same as SWCLK, cannot be driven low to 0V, as nRST pin.
Is there anything we can do to further identify the root cause of the failure?
Can anyone shed some light on this?
Zt.
