Bootloader STM32F4 pin unused default status

[Francois Alexandre]

Hello,

I have a working board with a STM32F429ZIT6, 144 pin MCU, which is fine.

I also can update in the field, this MCU using the internal bootloader ( AN2606). However, I ve noticed something odd.

During the bootloader (using stm32flash utility UART1 ), the pin PA12 (pin 104) stays at logical one during bootloader update.

This is problematic for me.. I don't understand why...

Where can get infos on what pins stays high or low during bootloader update?

thanks in advance for anyone

regards

[Tesla DeLorean]

Not sure ST enumerates things at this level, the AN2606 should scope the pins involved by the boot loader, as it is expecting connectivity on all listed interfaces. I'd expect I2C pins to be pulled high, and CAN pins to be in appropriate states to function as a bus.

Check if your FAE has some more chip specific breakdown.