18.104.22.168. RX FCS Checking
The RX MAC checks the FCS of all incoming packets that are minimum sized or larger. If the RX MAC Avalon ST detects an FCS error, it marks the frame invalid by asserting o_rx_error. IF the RX MAC segmented detects an FCS error, it marks the frame invalid by asserting o_rx_mac_rcs_error. FCS errors are also indicated for arriving packets containing an Error control block.