Frame Check Sequence (FCS) Error

Every decoded RX frame undergoes a CRC check at the XGMII RX. If the CRC check fails, then there is an error in the RX frame. When this occurs, the Ethernet 10G MAC core asserts RX_AXI_TUSER and increments the RX statistic reporting, cnt_rx_frame_error_fcs. Figure 1 describes a RX frame with FCS error. FCS error is also known as CRC error.