oosiop_period
sc->sc_minperiod = oosiop_period(sc, 4, sc->sc_ccf);
sc->sc_minperiod = oosiop_period(sc, 4, 10);
p = oosiop_period(sc, i, sc->sc_ccf);
p = oosiop_period(sc, synctbl[i].tp + 4,