Datasheet

Section 20 Ethernet Controller (EtherC)
Rev. 2.00 Aug. 20, 2008 Page 779 of 1198
REJ09B0403-0200
20.4.2 Reception
The EtherC receiver separates the frame data that inputs from the RMII into preamble, SFD, data,
and CRC data, and outputs from D/A (destination address) to CRC data to the E-DMAC. Figure
20.3 shows the state transitions of the EtherC receiver.
Illegal carrier
detection
Start of frame
reception
Wait for SFD
reception
Data
reception
CRC
reception
Destination address
reception
Preamble
detection
Reception
halted
Reset
Error
notification*
RE set
[Legend]
SFD: Start frame delimiter
Note: * The error frame also transmits data to the buffer.
End of
reception
Receive error
detection
Receive error
detection
Error
detection
Promiscuous and other
station destination address
RE reset
Normal reception
Idle
RX-DV negation
SFD
reception
Own destination address
or broadcast
or multicast
or promiscuous
Figure 20.3 EtherC Receiver State Transmissions
1. When the receive enable (RE) bit is set, the receiver enters the receive idle state.
2. When an SFD (start frame delimiter) is detected after a receive packet preamble, the receiver
starts receive processing. Discards a frame with an invalid pattern.
3. In normal mode, if the destination address matches the receiver’s own address, or if broadcast
or multicast transmission or promiscuous mode is specified, the receiver starts data reception.