SAB_RFC
SAB_WRITE(sc, SAB_RFC,
r = sc->sc_pollrfc = SAB_READ(sc, SAB_RFC);
SAB_WRITE(sc, SAB_RFC, r);
SAB_WRITE(sc, SAB_RFC, sc->sc_pollrfc);
SAB_WRITE(sc, SAB_RFC, SAB_READ(sc, SAB_RFC) & ~SAB_RFC_RFDF);