CR1
| PE | Peripheral enable |
| SMBUS | SMBus mode |
| SMBTYPE | SMBus type |
| ENARP | ARP enable |
| ENPEC | PEC enable |
| ENGC | General call enable |
| NOSTRETCH | Clock stretching disable (Slave mode) |
| START | Start generation |
| STOP | Stop generation |
| ACK | Acknowledge enable |
| POS | Acknowledge/PEC Position (for data reception) |
| PEC | Packet error checking |
| ALERT | SMBus alert |
| SWRST | Software reset |