In standard libs for STM32 if you user 8 bit and even/odd parity it automatically switch it to 7 bit of data and one bit of parity and so for 9 bit and parity it convert it to 8bit plus parity bit but it seems that I doesn’t like to work 7bit plus parity bit using RTE uart driver just hang and stay so. We use it on 1107 protocol and if I want to use RTE device diver and use prot to connect to my 1107 device it just hang