Error Frame
Error frame is XGMII_RXD = FE and the
XGMII_RXC = 1. When an error frame occurs, the
final 4 octets are decoded as CRC, resulting in a CRC error. Here, the Ethernet 10G MAC core asserts RX_AXI_TUSER and increments
the RX statistic reporting, cnt_rx_frame_errors and
cnt_rx_frame_error_fcs. Refer to Figure 2.