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STM32G0 that just won't connect

Associate II

Hey All,

I made my first STM32 board using STM32G0B1RE, it arrived today, since it's blank I expected the MCU to jump into bootloader and start the DFU, however this did not happen, MCU was not detected at all by the USB, I checked further and USB DP was not pulled high which was unexpected.


To check if the MCU has been entered the bootloader I check the UART TX and I2C SCK pins, and they are indeed high, indicating that MCU was indeed entered the bootloader. However, MCU is again not detected by UART.


Finally, I decided use another NUCLEO board as a programmer with the SWD interface, again, the MCU is not detected. I expect the SWD interface to work irrespective of bootloader.


Pulling up or down the BOOT0 makes no difference. I probed the board, and everything seems normal, voltages connections etc. I have 220 ohms series resistor on the SWD interface, which is little on the high side, but I don't think that should make a difference. 


It just seems like MCU enters into bootloader, tries to initialize the peripherals, and just freezes. Only thing that seems to be working it the RESET pin, when it's pulled low all GPIOs go low


Kind Regards,



Accepted Solutions
ST Employee

Dear @s_bhonwal ,

That is an unexpected behavior , try again with SWD to connect under reset and if possible to have the screenshots of the Logs using CubeProgrammer or your debugger. It might be the MCU was protected accidentally.

also to ask if you have another part you can try ?



Associate II