SM502_SRC
bus_space_write_4(sc->sc_memt, sc->sc_regh, SM502_SRC,
bus_space_write_4(sc->sc_memt, sc->sc_regh, SM502_SRC, 0);
bus_space_write_4(sc->sc_memt, sc->sc_regh, SM502_SRC, 0);
bus_space_write_4(sc->sc_memt, sc->sc_regh, SM502_SRC, 0);