Hi all,
We have a product containing the STM32G030K8T6 MCU. The code is working like expected and the product is meeting all specifications. The product is battery powered and can be charged via USB. So far so good.
If the product is assembled it will go into a burn-in test where 70 plus products will be charged and de-charged between 3 to 10 times. During this test 1 to 3 products are failing, and with failing I mean the MCU just stops operation.
It stops at the following line of code:
We found a lot of high dV/dt on the powerline and think this is causing the MCU to hang although we cannot reproduce on a single piece.
If we test products randomly on bench or at our desk it doens't have any issues.
Currently we are at a dead end, does anybody has any suggestions?
What development tools do you have?
It should be possible to connect to a running target without downloading & resetting:
@PLER wrote:During this test 1 to 3 products are failing
Is consistently the same 1-3 which exhibit this "hang" ?
Is it consistent where in the test sequence the "hangs" start occurring?
@PLER wrote:We found a lot of high dV/dt on the powerline and think this is causing the MCU to hang
Have you tried addressing that?
ie, if you prevent the high dV/dt, do the failures stop?
@PLER wrote:products will be charged and de-charged between 3 to 10 times.
So, apart from high dV/dt, you could also be having brown-outs? Have you looked into that?
EDIT:
What does it take to recover from a "hang" - just a reset? a full power-cycle? other?
Please use this button to properly post source code:
@PLER wrote:During this test 1 to 3 products are failing
Is consistently the same 1-3 which exhibit this "hang" ?
Is it consistent where in the test sequence the "hangs" start occurring?
It is random, there is no pattern.
@PLER wrote:During this test 1 to 3 products are failing
Is consistently the same 1-3 which exhibit this "hang" ?
Is it consistent where in the test sequence the "hangs" start occurring?
@PLER wrote:We found a lot of high dV/dt on the powerline and think this is causing the MCU to hang
Have you tried addressing that?
ie, if you prevent the high dV/dt, do the failures stop?
@PLER wrote:products will be charged and de-charged between 3 to 10 times.
So, apart from high dV/dt, you could also be having brown-outs? Have you looked into that?
EDIT:
What does it take to recover from a "hang" - just a reset? a full power-cycle? other?
Please use this button to properly post source code:
If I supply high dV/dt to a single product nothing happens to the product. The problem only arises at the burn in facility (which is not the same location), where they are connected in group to the same mains.
At our lab I made a test setup with the same simple USB charger. Interrupting the mains on an irregular base generates spikes which ripple further via the power path into the system. The ringing is visible on the Vdd of the MCU. Besides the ringing, the supply voltage is flat and stable.
In case the MCU comes into a hang state the only way to get out is by re-flashing the code. Resetting or power-cycling the MCU are not doing the job.
The occurrence of the error is very random, no pattern is visible. This makes it a very hard error to find.
The burn-in cannot be changed.
