Dropped tx_axis_mac_tvalid Before End of Frame
Streaming data is defined as continuous valid data bytes from the start of frame (SOF)
until the end of frame (EOF). This requires that tx_axis_mac_tvalid
remains asserted for every cycle between SOF to EOF.
Cut Through Mode
In Cut Through mode, if tx_axis_mac_tvalid is
deasserted before EOF, the continuity of streaming data is broken. When this occurs,
the Triple Speed Ethernet MAC core terminates the transmission with an error
frame and drops the remaining frame. This event increments the
aTxIncontinuityFramesErrors counter.
Cut-Through Mode with Width-Adaptation or Store-Forward Mode
In Cut Through mode with width-adaptation or Store
Forward mode, a dropped tx_axis_mac_tvalid simply
indicates that the corresponding column of tx_axis_mac signals are
not written into TXFIFO.
Therefore, in Cut Through mode with width-adaptation or
Store Forward mode, a dropped
tx_axis_mac_tvalid does not result in an error frame.