This Figure shows an Aurora 64B/66B core with an 8-byte data interface receiving a 4-byte UFC message. The core presents this data to the application by asserting m_axi_ufc_rx_tvalid and m_axi_ufc_rx_tlast indicating a single-cycle frame. The m_axi_ufc_rx_tkeep bus is set to 0xF , indicating only the four most significant interface bytes are valid (each bit in TKEEP indicates a valid byte in the UFC data).
