Interrupt Status Flags.
| RX_FRAME_ERROR | FLAG for RX Frame Error Interrupt. |
| RX_PARITY_ERROR | FLAG for RX Parity Error interrupt. |
| CTS_CHANGE | FLAG for CTS signal change interrupt. |
| RX_OVERRUN | FLAG for RX FIFO Overrun interrupt. |
| RX_FIFO_THRESH | FLAG for interrupt when RX FIFO reaches the number of bytes configured by the RXTHD field. |
| TX_FIFO_ALMOST_EMPTY | FLAG for interrupt when TX FIFO has only one byte remaining. |
| TX_FIFO_THRESH | FLAG for interrupt when TX FIFO reaches the number of bytes configured by the TXTHD field. |
| BREAK | FLAG for received BREAK character interrupt. |
| RX_TIMEOUT | FLAG for RX Timeout Interrupt. Trigger if there is no RX communication during n UART characters (n=UART_CN.RXTO). |
| LAST_BREAK | FLAG for Last break character interrupt. |