I could not find any register where RX FIFO Time out interrupt can be enabled?

If the UART is enabled in FIFO mode, the Rx FIFO timeout interrupt occurs if all of the following conditions are satisfied. There is no need for any other register configuration.

  1. At least one character is in the FIFO
  2. The most recent character was received more than four continuous character times ago. A character time is the time allotted for 1 START bit, n data bits, 1 PARITY bit, and 1 STOP bit, where n depends on the word length selected with the WLS bits in the line control register (LCR).
  3. The most recent read of the FIFO has occurred more than four continuous character times before.

The status of the interrupt can be checked in COMIIR - Interrupt ID register (REG_UART0_COMIIR)

Tags: aducm302x uart_protocol