Interrupt Enable Register
| RXRDY | Enable RXRDY Interrupt |
| TXRDY | Enable TXRDY Interrupt |
| ENDRX | Enable End of Receive Transfer Interrupt |
| ENDTX | Enable End of Transmit Interrupt |
| OVRE | Enable Overrun Error Interrupt |
| FRAME | Enable Framing Error Interrupt |
| PARE | Enable Parity Error Interrupt |
| TXEMPTY | Enable TXEMPTY Interrupt |
| TXBUFE | Enable Buffer Empty Interrupt |
| RXBUFF | Enable Buffer Full Interrupt |