MTD_READ_4
MTD_WRITE_4((sc), (reg), MTD_READ_4((sc), (reg)) | (x))
MTD_WRITE_4((sc), (reg), MTD_READ_4((sc), (reg)) & ~(x))
status = MTD_READ_4(sc, MTD_ISR);
rxtx_stat = MTD_READ_4(sc, MTD_RXTXR);
if (!(MTD_READ_4(sc, MTD_BCR) & MTD_BCR_RESET))