SACCGPIOA_DVR
bus_space_write_4(sc->sc_iot, sc->sc_ioh, SACCGPIOA_DVR,
bus_space_write_4( sc->sc_iot, sc->sc_ioh, SACCGPIOA_DVR, 0 );
oldval = bus_space_read_4(sc->sc_iot, sc->sc_ioh, SACCGPIOA_DVR);
bus_space_write_4(sc->sc_iot, sc->sc_ioh, SACCGPIOA_DVR, newval);