Ethernet MAC debug register
| MMRPEA | MAC MII receive protocol engine active |
| MSFRWCS | MAC small FIFO read / write controllers status |
| RFWRA | Rx FIFO write controller active |
| RFRCS | Rx FIFO read controller status |
| RFFL | Rx FIFO fill level |
| MMTEA | MAC MII transmit engine active |
| MTFCS | MAC transmit frame controller status |
| MTP | MAC transmitter in pause |
| TFRS | Tx FIFO read status |
| TFWA | Tx FIFO write active |
| TFNE | Tx FIFO not empty |
| TFF | Tx FIFO full |