Altera POS-PHY Level 4 IP Core - Manual (Page 59)

Chapter 4: Functional Description—Receiver 4–21
Error Flagging and Handling
December 2014 Altera Corporation POS-PHY Level 4 IP Core User Guide
Missing SOP
If incoming data contains one or more EOPs without corresponding SOPs (refer to
Figure 4–9 ), the block deasserts the enable after the last EOP (refer to Figure 4–10 ).
This deassertion indicates that the current data between the SOP to EOP transition is a
valid packet, and that everything following the EOP is discarded until the next SOP is
received. None of the packets are marked as errored, so it is up to the user logic to
determine which cells or packets have been dropped.
Figure 4–9. Missing SOP Input Timing Diagram
Figure 4–10. Missing SOP Output Timing Diagram
Missing SOP
aN_arxeop
aN_arxerr
aN_arxtclk
aN_arxena
aN_arxsop
err_ry_msopN
aN_arxeop
aN_arxerr
aN_arxtclk
aN_arxena
aN_arxsop