SWCU194 March 2023 CC1314R10 , CC1354P10 , CC1354R10 , CC2674P10 , CC2674R10
The UART can be placed into an internal loopback mode for diagnostic or debug work by setting the UART:CTL.LBE register bit. In loopback mode, data transmitted on the UARTTXD output is received on the UARTRXD input. The LBE bit must be set before the UART is enabled.