IER_EMSC
if (ISSET(sc->sc_ier, IER_ERXRDY | IER_ETXRDY | IER_ERLS | IER_EMSC))
if (ISSET(sc->sc_imr, IER_ERXRDY | IER_ETXRDY | IER_ERLS | IER_EMSC))
sc->sc_ier |= IER_EMSC;
if (ISSET(sc->sc_ier, IER_ERXRDY | IER_ETXRDY | IER_ERLS | IER_EMSC))