4.5.7. Overflow Handling
When an overflow occurs on the client side, the client can backpressure the Avalon® streaming receive interface by deasserting the avalon_st_rx_ready signal. If an overflow occurs, the MAC RX sets the error bit, avalon_st_rx_error, to 1 to indicate an overflow. The MAC RX drops subsequent frames if the overflow condition persists. The MAC RX then continues to receive data when the overflow condition ceases.