Cut and paste this URL to share the unmodified register and value:
https://regviz.com/r/Nuvoton/NUC1xx_registers/UART0/UA_IRCR#0x0
IrDA Control Register.
Enable IrDA Receiver 1: Enable IrDA transmitter 0: Enable IrDA receiver
INV_TX 1= Inverse TX output signal 0= No inversion
INV_RX 1= Inverse RX input signal 0= No inversion
https://github.com/cmsis-svd/cmsis-svd-data