SWPMI Interrupt Enable register
| RXBFIE | Receive buffer full interrupt enable |
| TXBEIE | Transmit buffer empty interrupt enable |
| RXBERIE | Receive CRC error interrupt enable |
| RXOVRIE | Receive overrun error interrupt enable |
| TXUNRIE | Transmit underrun error interrupt enable |
| RIE | Receive interrupt enable |
| TIE | Transmit interrupt enable |
| TCIE | Transmit complete interrupt enable |
| SRIE | Slave resume interrupt enable |