BT848_INT_VSYNC
btand(~BT848_INT_VSYNC, BT848_INT_MASK);
btor(BT848_INT_VSYNC, BT848_INT_MASK);
btor(BT848_INT_VSYNC, BT848_INT_MASK);
btor(BT848_INT_VSYNC, BT848_INT_MASK);
btor(BT848_INT_VSYNC, BT848_INT_MASK);
btor(BT848_INT_VSYNC, BT848_INT_MASK);
if (astat&BT848_INT_VSYNC)
btand(~BT848_INT_VSYNC, BT848_INT_MASK);