Ethernet MAC configuration register (ETH_MACCR)
| RE | Receiver enable |
| TE | Transmitter enable |
| DC | Deferral check |
| BL | Back-off limit |
| APCS | Automatic pad/CRC stripping |
| RD | Retry disable |
| IPCO | IPv4 checksum offload |
| DM | Duplex mode |
| LM | Loopback mode |
| ROD | Receive own disable |
| FES | Fast Ethernet speed |
| CSD | Carrier sense disable |
| IFG | Interframe gap |
| JD | Jabber disable |
| WD | Watchdog disable |