SA3_DPWRDWN
i == SA3_DPWRDWN)
ym_write(sc, SA3_DPWRDWN, sc->sc_sa3_scan[SA3_DPWRDWN]);
ym_write(sc, SA3_DPWRDWN,
ym_read(sc, SA3_DPWRDWN) | (u_int8_t) parts);
ym_write(sc, SA3_DPWRDWN,
ym_read(sc, SA3_DPWRDWN) & (u_int8_t)~parts);
ym_write(sc, SA3_DPWRDWN, dpd);