SWCU193A April 2023 – August 2024 CC2340R2 , CC2340R5 , CC2340R5-Q1
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.