SMT32L4xx blocked by bootloader

WYWF · ‎2023-10-25

Hi all,

I'm using stm32l431 and met a problem as below.

After power up a new stm32l431 board which had not been programmed before, the MCU enter bootloader progam and the PC value is 0x1FFF xxxx. Downlaod my own code to MCU but the code and not run.

Then, erase the MCU flash by "STM32Cube progammer", the MCU can work.

BTW, boot0 and RESET pin connect correctly.

TDK · ‎2023-10-25

If you want STM32CubeProgrammer to run directly after downloading, disconnect, reconnect, and then disconnect.

Also, the empty check mechanism is read on power-up, not reset. You either have to power cycle it or reload the option bytes. See here for more info:

https://community.st.com/t5/stm32-mcus/empty-check-mechanism-on-stm32/ta-p/49369

If you feel a post has answered your question, please click "Accept as Solution".

View solution in original post

Sarra.S · ‎2023-10-25

Welcome @WYWF to ST Community,

The bootloader is activated by applying some patterns

Please check Table 2. Bootloader activation patterns in AN2606

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TDK · ‎2023-10-25

If you want STM32CubeProgrammer to run directly after downloading, disconnect, reconnect, and then disconnect.

Also, the empty check mechanism is read on power-up, not reset. You either have to power cycle it or reload the option bytes. See here for more info:

https://community.st.com/t5/stm32-mcus/empty-check-mechanism-on-stm32/ta-p/49369

If you feel a post has answered your question, please click "Accept as Solution".

WYWF · ‎2023-10-26

Thanks for your reply, I fixed this issue by modify 'Option bytes'