MQ200_GCVSCR
reg = mq200_read(sc, MQ200_GCVSCR(gc));
#define MQ200_GC1VSCR MQ200_GCVSCR(0)
#define MQ200_GC2VSCR MQ200_GCVSCR(1)
mq200_write(sc, MQ200_GCVSCR(MQ200_GC1),