Unable to connect to STM32H7 system bootloader via UART

[SP.12]

I have been working with STM32H753 device. I was able to boot into the system booltoader of the Nucleo board. Cube Programmer was able to detect and connect through UART.

But, I am unable to connect the Cube programmer in our custom board. Both BOOT_ADD0 and BOOT_ADD1 were set to 0x1FF0. After booting, I connected J-Link to verify that the PC is at 0x1FFx series addresses.

Looking further, whenver I halt and run the CPU through J-Link, the PC seems to be at address 0x1FF0AAF0 and the CycleCnt is increasing.

I am not sure what could be possibly wrong.

[MM..1]

You need use exact pins and config described in AN2606 for example

[SP.12]

Hi, thanks for the response. I did use the mentioned pin for USART1 - PA9 and PA10 from AN2606. The same set of pins were working on the Nucleo, but not in our custom board.

[MM..1 · Accepted solution]

You meet all this

[SP.12]

The PB15 was set to GND in our case. And changing it, solved our issue. We are able to connect to the bootloader now. Thank you very much.