regwb
regwb(sc, DAC_MASK, 0xff);
regwb(sc, DAC_WINDEX, index);
regwb(sc, DAC_DATA, r);
regwb(sc, DAC_DATA, g);
regwb(sc, DAC_DATA, b);
regwb(sc, CLOCK_CNTL + 1, index << 2);