Interrupt Enable Register
| RXRDY | RXRDY Interrupt Enable |
| TXRDY | TXRDY Interrupt Enable |
| RXBRK | Receiver Break Interrupt Enable |
| ENDRX | End of Receive Transfer Interrupt Enable (available in all USART modes of operation) |
| ENDTX | End of Transmit Interrupt Enable (available in all USART modes of operation) |
| OVRE | Overrun Error Interrupt Enable |
| FRAME | Framing Error Interrupt Enable |
| PARE | Parity Error Interrupt Enable |
| TIMEOUT | Time-out Interrupt Enable |
| TXEMPTY | TXEMPTY Interrupt Enable |
| ITER | Max number of Repetitions Reached Interrupt Enable |
| TXBUFE | Buffer Empty Interrupt Enable (available in all USART modes of operation) |
| RXBUFF | Buffer Full Interrupt Enable (available in all USART modes of operation) |
| NACK | Non AcknowledgeInterrupt Enable |
| CTSIC | Clear to Send Input Change Interrupt Enable |