Interrupt Enable Register.
| RX_FRAME_ERROR | Enable for RX Frame Error Interrupt. |
| RX_PARITY_ERROR | Enable for RX Parity Error interrupt. |
| CTS | Enable for CTS signal change interrupt. |
| RX_OVERRUN | Enable for RX FIFO OVerrun interrupt. |
| RX_FIFO_LVL | Enable for interrupt when RX FIFO reaches the number of bytes configured by the RXTHD field. |
| TX_FIFO_AE | Enable for interrupt when TX FIFO has only one byte remaining. |
| TX_FIFO_LVL | Enable for interrupt when TX FIFO reaches the number of bytes configured by the TXTHD field. |
| BREAK | Enable for received BREAK character interrupt. |
| RX_TO | Enable for RX Timeout Interrupt. Trigger if there is no RX communication during n UART characters (n=UART_CN.RXTO). |
| LAST_BREAK | Enable for Last break character interrupt. |