Hi,We use DMA in our production code, which is where we first observed the behavior.We do not use DMA in the project to find the error. In this troubleshooting project, exactly one UART frame is generated using a pattern generator. This one byte is a...

We have exactly the same problem here after we swapped the controller from F103 to L431 on a board. After investigating the problem more closely, we are very sure that it is a problem with the UART/USART peripheral. A short pulse during the stop bit ...