SPRUIU1C July 2020 – February 2024 DRA821U , DRA821U-Q1
In IrDA modes, sleep mode is enabled by setting the UART_MDR1[3] IR_SLEEP bit to 1.
Sleep mode is entered when all of the following conditions exist:
The module wakes up when a change is detected on the RXD line or when data is written to the TX FIFO.