Question
STM32G4 stuck on interrupt call
Hello everyone,
I’m currently working with an STSPIN32G4 MCU on a custom board.
Two version of this board exist: version A and version B.
When I upload the firmware to the MCU on board A everything works correctly. The exact same firmware on version B doesn’t work.
What happens:
- Board B is powered on and the MCU is still fabric new (no firmware uploaded)
- The custom fw is uploaded using the “Debug” feature of STM32CUBEIDE via JTAG
- The code is executed succesfully by the MCU
- Board B is powered off
- After repowering on board B the issue starts to present: the firmware gets stuck as soon as any interrupt is called
Here’s an image of where the program points at when I press stop on the debugger after an interrupt call

What has already been tried:
- Performing a full chip erase on the MCU and redownloading the firmware, but it still gets stuck on interrupt call
- Removing the interrupt that was causing the firmware to get stuck (UART1 interrupt), but it still gets stuck as soon as TIM2 interrupt gets called
- Removing all the interrupts and the firmware runs fine
- Trying programming another board B, but the same issue is present
- Comparing the OB of board B and board A and they are all the same. Both MCUs have boot mode set as software only, ignoring BOOT0’s pin value

- Verifying the stability of the power supply on board B
- Veryfing the correct frequency of the external crystal resonator
