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AR# 43421

Design Advisory for LogiCORE IP Ethernet 1000BASE-X PCS/PMA or SGMII v11.1 - GMII_RX_ER Not Asserted when Link Lost during Frame


If in the middle of the reception of a frame, a constant stream of not in tables and disparity errors are seen, then GMII_RX_DV goes low and the core loses synchronization.

However, GMII_RX_ER is not asserted for the frame.

This sequence happens when using the LogiCORE IP Ethernet 1000BASE-X PCS/PMA or SGMII v11.1 and earlier cores.


Per the 802.3 1000BASE-X receive state machines, GMII_RX_ER should be asserted, but the MAC layer still marks the frame as bad because there is a Frame Check Sequence (FCS) error.

This is scheduled to be resolved in the next version of the core.

In the meantime, a patch is available for v11.1 of the core.

Please see (Xilinx Answer 40625) to download the patch.

Linked Answer Records

Master Answer Records

AR# 43421
Date Created 08/01/2011
Last Updated 02/24/2015
Status Active
Type Design Advisory
  • Ethernet 1000BASE-X PCS/PMA or SGMII