uint32_tupfd:1;/*A pause frame is processed when it has the unique multicast address specified in the IEEE Std 802.3. When this bit is set the MAC can also detect Pause frames with unicast address of the station. This unicast address should be as specified in the EMACADDR0 High Register and EMACADDR0 Low Register. When this bit is reset the MAC only detects Pause frames with unique multicast address.*/