MQ200_GCHDCR
reg = mq200_read(sc, MQ200_GCHDCR(gc));
#define MQ200_GC1HDCR MQ200_GCHDCR(0)
#define MQ200_GC2HDCR MQ200_GCHDCR(1)
mq200_write(sc, MQ200_GCHDCR(MQ200_GC1),