BT848_IFORM
btaor((2)<<5, ~(2<<5), BT848_IFORM);
btaor(2<<5, ~BT848_IFORM_MUXSEL, BT848_IFORM);
btand(~BT848_IFORM_MUXSEL,BT848_IFORM);
BT848_IFORM);
btwrite(BT848_IFORM_XTAUTO | BT848_IFORM_AUTO, BT848_IFORM);
btaor(mux<<5, ~(3<<5), BT848_IFORM);