Status Register
| RDRF | Receive Data Register Full |
| TDRE | Transmit Data Register Empty |
| MODF | Mode Fault Error |
| OVRES | Overrun Error Status |
| ENDRX | End of RX buffer |
| ENDTX | End of TX buffer |
| RXBUFF | RX Buffer Full |
| TXBUFE | TX Buffer Empty |
| NSSR | NSS Rising |
| TXEMPTY | Transmission Registers Empty |
| UNDES | Underrun Error Status (Slave Mode Only) |
| SPIENS | SPI Enable Status |