Can't find boot1 on GUI on many STM32

Cyril C · ‎2023-06-21

Hello,

I'm currently using stm32F410, i want to get to the system memory in order to use bootloader in UART and upgrade my firmware. I saw on datasheet that i need to pilot pin BOOT1. The problem is that on the graphical interface of STM32CubeIDE or CubeMx, when i click on PB2 (that should have the additionnal function "BOOT1"), i can't find BOOT1.

I saw that someone had a problem like this in 2018. I would like to know if it's fix or if there's another way to do it. I tried some otherm STM such as STM32F401 / F407, same problem. Only one card worked, it was the STM32F303 because i have to configure option bytes for BOOT1 and not pins.

Waiting for your responses.
Thanks.

Cyril.

Peter BENSCH · ‎2023-06-21

The pin does not have to be specially configured as BOOT1, but is queried (sampled) exactly once with the fourth rising edge of SYSCLK after a reset. The schematics would therefore have to be designed in such a way that BOOT1 (PB2) can be set accordingly without significantly disturbing or even damaging the application.

Regards
/Peter

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Peter BENSCH · ‎2023-06-21

This may indeed be confusing, however the RM0401, section 2.6 writes about it:

The values on the BOOT pins are latched on the 4th rising edge of SYSCLK after a reset. It
is up to the user to set the BOOT1 and BOOT0 pins after reset to select the required boot
mode.

BOOT0 is a dedicated pin while BOOT1 is shared with a GPIO pin. Once BOOT1 has been
sampled, the corresponding GPIO pin is free and can be used for other purposes.

Hope that helps?

Regards
/Peter

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Cyril C · ‎2023-06-21

Thanks for responding that quick.

Actually, i don't know how to configure it when it doesn't appear on the GUI. What do you mean by sampling BOOT1 ?

Regards,

Cyril.

Peter BENSCH · ‎2023-06-21

The pin does not have to be specially configured as BOOT1, but is queried (sampled) exactly once with the fourth rising edge of SYSCLK after a reset. The schematics would therefore have to be designed in such a way that BOOT1 (PB2) can be set accordingly without significantly disturbing or even damaging the application.

Regards
/Peter

In order to give better visibility on the answered topics, please click on Accept as Solution on the reply which solved your issue or answered your question.

Cyril C · ‎2023-06-22

It worked, thanks you, now i have to talk with my bootloader 🙂

Peter BENSCH · ‎2023-06-22

Great!

If the problem is solved, please mark this thread as answered by selecting Accept as Solution, as also explained here. This will help other users find that answer faster.

Good luck!
/Peter

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