uint32_tmactfcs:2;/*This field indicates the state of the MAC Transmit Frame Controller module: 2'b00: IDLE state. 2'b01: Waiting for status of previous frame or IFG or backoff period to be over. 2'b10: Generating and transmitting a Pause frame (in the full-duplex mode). 2'b11: Transferring input frame for transmission.*/