STM32MP15 OTP Mapping Wiki

[BBoge.2]

Hey I found a strange documentation on your wiki page

https://wiki.st.com/stm32mpu/wiki/STM32MP15_OTP_mapping

3:

14-7 (8 bits)UART instances disablingIf it is different from zero, then each bit disables an UART instance.

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• 0b00000001: reserved
• 0b00000010: disable USART2
• 0b00000100: disable USART3
• 0b00001000: disable UART4
• 0b00010000: disable UART5
• 0b00100000: disable UART6
• 0b01000000: disable UART7
• 0b10000000: disable USART8
• 0b11111111: all UART instances are enabled.

Why is all enabled when all UARTS are 1?

I set everything to 1 but I get messages on the serial console.

Do you have a hint for me?

Greetings

[BBoge.2]

If I set all bit to 1 in the otp 3. The serial communication will work as before.

For example:

fuse prog -y 0 3 0x185B7F04

But after stm32key close the serial communication is still open.

[OlivierK · Accepted solution]

Hi BBoge.2 (Community Member)

0b11111111: all UART instances are enabled

This is a protection to avoid bricking all the USART ports by mistake.

If you want to disable all UART instances at once, you should use OTP3.23-16 boot source disable instead (disable UART boot source).

Rgds,

Olivier

[BBoge.2]

Hey Oliver,

and when I try to disable the serial console that prints everything over UART?

Greetings

Benedikt

[PatrickF]

Hi @BBoge.2​ 

This OTP is related to BootROM UART usage (i.e. connection with CubeProgrammer).

This has nothing to do with Console usage.

I'm not expert, but I think console should likely be disabled using Device Tree.

Regards.

[BBoge.2]

Hi Patrick,

okay maybe there was a miss understanding from point of view.

Thanks for your support.

Greetings

Benedikt