Cut and paste this URL to share the unmodified register and value:
https://regviz.com/r/STMicroelectronics/STM32W108/SC1_UART/SC1_UARTCR#0x0
Serial controller UART control register
nRTS
M
STOP
PCE
PS
HFCE
AHFCE
https://github.com/cmsis-svd/cmsis-svd-data