11.2.2 MAC Network Configuration Register
| Name: | MAC_NCFGR |
| Address: | 0x001 |
| Reset: | 0x00080000 |
| Property: | Read/Write |
| Bit | 31 | 30 | 29 | 28 | 27 | 26 | 25 | 24 | |
| RXBP | IRXFCS | EFRHD | |||||||
| Access | R/W | R/W | R/W | R/W | R/W | R/W | R/W | R/W | |
| Reset | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 |
| Bit | 23 | 22 | 21 | 20 | 19 | 18 | 17 | 16 | |
| RFCS | LFERD | ||||||||
| Access | R/W | R/W | R/W | R/W | R/W | R/W | R/W | R/W | |
| Reset | 0 | 0 | 0 | 0 | 1 | 0 | 0 | 0 |
| Bit | 15 | 14 | 13 | 12 | 11 | 10 | 9 | 8 | |
| MAXFS | |||||||||
| Access | R/W | R/W | R/W | R/W | R/W | R/W | R/W | R/W | |
| Reset | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 |
| Bit | 7 | 6 | 5 | 4 | 3 | 2 | 1 | 0 | |
| UNIHEN | MTIHEN | NBC | CAF | DNVLAN | |||||
| Access | R/W | R/W | R/W | R/W | R/W | R/W | R/W | R/W | |
| Reset | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 |
Bit 29 – RXBP Receive Bad Preamble
When written to '1', frames with non-standard preamble are not rejected.
Bit 26 – IRXFCS Ignore RX FCS
For normal operation this bit must be written to zero.
When this bit is written to '1', frames with FCS/CRC errors will not be rejected. FCS error statistics will still be collected for frames with bad FCS, and FCS status will be recorded in the DMA descriptor of the frame.
Bit 25 – EFRHD Enable Frames Received in half-duplex
Writing a '1' to this bit enables frames to be received in half-duplex mode while transmitting.
Bit 17 – RFCS Remove FCS
Writing this bit to '1' will cause received frames to be written to memory without their frame check sequence (last 4 bytes). The indicated frame length will be reduced by four bytes in this mode.
Bit 16 – LFERD Length Field Error Frame Discard
Writing a '1' to this bit discards frames with a measured length shorter than the extracted length field (as indicated by bytes 13 and 14 in a non-VLAN tagged frame). This only applies to frames with a length field less than 0x0600.
Bit 8 – MAXFS 1536 Maximum Frame Size
Writing a '1' to this bit increases the maximum accepted frame size to 1536 bytes in length. When written to '0', any frame above 1518 bytes in length is rejected.
Bit 7 – UNIHEN Unicast Hash Enable
When writing a '1' to this bit, unicast frames will be accepted when the 6-bit hash function of the destination address points to a bit that is set in the Hash Register.
Writing a '0' to this bit disables unicast hashing.
Bit 6 – MTIHEN Multicast Hash Enable
When writing a '1' to this bit, multicast frames will be accepted when the 6-bit hash function of the destination address points to a bit that is set in the Hash Register.
Writing a '0' to this bit disables multicast hashing.
Bit 5 – NBC No Broadcast
Writing a '1' to this bit will reject frames addressed to the broadcast address 0xFFFFFFFFFFFF (all '1').
Writing a '0' to this bit allows broadcasting to 0xFFFFFFFFFFFF.
Bit 4 – CAF Copy All Frames
When writing a '1' to this bit, all valid frames will be accepted.
Bit 2 – DNVLAN Discard Non-VLAN Frames
Writing a '1' to this bit allows only VLAN-tagged frames to pass to the address matching logic.
Writing a '0' to this bit allows both VLAN-tagged and untagged frames to pass to the address matching logic.