control register 1
| CLKPHA | Clock phase |
| CLKPOL | Clock polarity |
| MSTEN | Master enable |
| MDIV2_0 | Master clock frequency division bit2-0 |
| SPIEN | SPI enable |
| LTF | LSB transmit first |
| SWCSIL | Software CS internal level |
| SWCSEN | Software CS enable |
| ORA | Only receive active |
| FBN | frame bit num |
| NTC | Next transmission CRC |
| CCEN | CRC calculation enable |
| SLBTD | Single line bidirectional half-duplex transmission direction |
| SLBEN | Single line bidirectional half-duplex enable |