Rabbit Rabbit 4000, User Manual

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216 Rabbit 4000 Microprocessor User’s Manual
Network Port A Transmit Control Register (NATCR) (Address = 0x020A)
Bit(s) Value Description
7 0 Disable transmitter.
1 Enable transmitter.
6 0 DMA request when FIFO is half empty.
1 DMA request when FIFO is one-fourth empty.
5:0 These bits are reserved and should be written with zeros.
Network Port A Receive Control Register (NARCR) (Address = 0x020B)
Bit(s) Value Description
7 0 Disable receiver.
1 Enable receiver.
6 0 DMA request when FIFO is half full.
1 DMA request when FIFO is one-fourth full.
5 0 Normal receiver operation.
1
Place receiver in Monitor mode. Receiver operates normally, but does not buffer
frames to memory.
4 0 Receive frames less than 64 bytes in length discarded.
1 Receive frames as short as 8 bytes accepted.
3 0 Receive frames with errors discarded. Reclaim buffer space.
1 Receive frames with errors accepted. Do not reclaim buffer space.
2 0 Receive frames with broadcast address ignored.
1 Receive frames with broadcast address accepted
1 0 Receive frames with multicast addresses ignored.
1 Receive frames with multicast addresses accepted if passing hashing filter.
0 0 Receive frames with mismatched physical addresses are ignored.
1 Receive frames with any physical address accepted. Promiscuous mode.