STM32H723 bootloader via uart ,The first 32 bytes of the read command are all 0xff

[1234dingning1235678]

hello,everyone!

Recently, I found a strange problem when using STM32H723's bootloader to download programs through uart.

When I tried to read out the 256 bytes I wrote and compared them, I found that the first 32 bytes were 0xff and the data after that was correct. After confirmation, these 32 bytes were indeed not written into flash, I don't know why?

[TDK]

Probably something else wrote those bytes before this. You can only write to a flash address once. After that, it must be erased before you can write again.

[1234dingning1235678]

thank you boy ! thank you reply!

and I understand what you mean, but if I don't read back the check, all the bytes written are correct, I have verified. Only after I read back will the first 32 bytes not be written in. It seems that the back reading affects the next writing process.

[TDK]

I don't see what else it could be. Doesn't make sense that reading memory would cause the next write memory command to fail. Can STM32CubeProgrammer write to those addresses using the UART bootloader?