URE_PLA_RXFIFO_CTRL2
ure_write_2(sc, URE_PLA_RXFIFO_CTRL2, URE_MCU_TYPE_PLA, URE_RXFIFO_THR3_NORMAL);
ure_write_4(sc, URE_PLA_RXFIFO_CTRL2, URE_MCU_TYPE_PLA, rx_fifo2);