Cut and paste this URL to share the unmodified register and value:
https://regviz.com/r/STMicroelectronics/STM32W108/SC1_UART/SC1_UARTSR#0x0
Serial controller UART status register
CTS
RXNE
TXE
OVR
FE
PE
IDLE
https://github.com/cmsis-svd/cmsis-svd-data