TX_ENABLE
bus_space_write_2(iot, ioh, EP_COMMAND, TX_ENABLE);
bus_space_write_2(iot, ioh, EP_COMMAND, TX_ENABLE);
bus_space_write_2(iot, ioh, EP_COMMAND, TX_ENABLE);
bus_space_write_2(iot, ioh, EP_COMMAND, TX_ENABLE);