DMA_INTR_ENABLE
HWRITE4(sc, DMA_INTR_ENABLE, 0);
HSET4(sc, DMA_INTR_ENABLE, DMA_INTR_ENABLE_TX_TRANSFER_DONE |
HSET4(sc, DMA_INTR_ENABLE, DMA_INTR_ENABLE_RX_MISSED_FRAME);