MQ200_GCVDCR
reg = mq200_read(sc, MQ200_GCVDCR(gc));
#define MQ200_GC1VDCR MQ200_GCVDCR(0)
#define MQ200_GC2VDCR MQ200_GCVDCR(1)
mq200_write(sc, MQ200_GCVDCR(MQ200_GC1),