USART Control A
| SWRST | Software Reset |
| ENABLE | Enable |
| MODE | Operating Mode |
| RUNSTDBY | Run during Standby |
| IBON | Immediate Buffer Overflow Notification |
| TXINV | Transmit Data Invert |
| RXINV | Receive Data Invert |
| SAMPR | Sample |
| TXPO | Transmit Data Pinout |
| RXPO | Receive Data Pinout |
| SAMPA | Sample Adjustment |
| FORM | Frame Format |
| CMODE | Communication Mode |
| CPOL | Clock Polarity |
| DORD | Data Order |