There's fundamental difference between ICAO definitions of DH/MDA and DH/MDA as entered into A320 FMGS.
On A320s I've flown (s/Nos around 1200) entering DH would arm autocallouts ("HUNDRED ABOVE" and "MINIMUMS") and "DH" display on PFD - with reference to radio altimeter. Setting MDA would merely display it on PFD and make alt digital readout turn yellow below it. It would have no bearing on LVP, autopilot or autoland capability whatsoever.
CAT 1 ILS has barometric altitude referenced minimum, therefore DA is entered into MDA field. If you fly by reference to QFE, then DH is inserted as MDA.
However, I'm only too glad that I was never allowed to use autoland on CAT 1 ILSes or autothrust while flying manually.