SR2
| MSL | Master/slave |
| BUSY | Bus busy |
| TRA | Transmitter/receiver |
| GENCALL | General call address (Slave mode) |
| SMBDEFAULT | SMBus device default address (Slave mode) |
| SMBHOST | SMBus host header (Slave mode) |
| DUALF | Dual flag (Slave mode) |
| PEC | acket error checking register |