An error-free control frame is a received frame matching the format of Figure 1. It must pass all standard receiver frame checks (for example, FCS field checking). In addition, the control frame received must be exactly 64 bytes in length (from destination address through to the FCS field inclusive (this is the minimum legal Ethernet MAC frame size and the defined size for control frames) or the Control Frame Length Check Disable must be set.
Any control frame received that
does not conform to these checks contains an error and is passed to
the receiver client with the rx_axis_tuser signal asserted on the cycle
that rx_axis_tlast is asserted.