Reason why stm32l412 read protection cannot be lowered

[孟祝.1]

When preparing to set the option byte, it is found that the read protection setting is at level 1 and cannot be changed to level 0. Then, it cannot be applied when preparing to apply, as shown in figures 5

[Imen.D]

Hello @孟�?� �?​ ,

You can try using STM32CubeProgrammer. Try connecting under reset.

Have you checked if this behavior has occurred with other boards?

When your question is answered, please come back to the Community with update and close this topic by choosing Select as Best.

Imen

[孟祝.1]

Thank you for your reply. When I download the program using stm32cubeprogrammer according to your suggestion, I still prompt "error: failed to erase memory", so I think the read-write protection should be cancelled. Is there any way to solve it? I haven't met in other development boards yet

[Imen.D · Accepted solution]

Try to set RDP option byte to 0xBB (level 1) and then back to 0xAA (level 0).

Please let me know if this solves your problem.

[Manny]

Are you able to connect to the target using stm32cubeprogrammer?

What was the condition of the mcu (where you able to program it earlier or it is a brand new mcu and has come with RDP out of the box)?

[孟祝.1]

According to the above suggestions, use stm32cubeprogrammer to set the RDP value to FF, and then restore it to AA value. The problem of read protection has been solved. Thank you very much.

[Imen.D]

Hi @孟�?� �?​ ,

Glad to know the issue has been solved, and thanks for closing this thread.

Imen