Frame Reception with Errors - 2.6 English

1G/10G/25G Switching Ethernet Subsystem Product Guide (PG292)

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2.6 English

An unsuccessful frame reception might take the form of a runt frame or a frame with an incorrect FCS. In this case, the bad frame is received and the signal rx_axis_tuser is asserted to the client at the end of the frame. It is then the responsibility of the client to drop the data already transferred for this frame.

The following conditions cause the assertion of rx_axis_tlast along with rx_axis_tuser = 1 signifying a bad_frame:

  • FCS errors occur.
  • Packets are shorter than 64 bytes (undersize or fragment frames).
  • Frames of length greater than the maximum transmission unit (MTU) Size programmed are received.
  • Any control frame that is received is not exactly the minimum frame length.
  • The XGMII data stream contains error codes.
Figure 1. Frame Reception with Errors – 32-bits

Figure 2. Frame Reception with Errors – 64-bits