UMCT_BULK_DT_WR
[UMCT_BULK_DT_WR] = {
sc->sc_obufsize = usbd_xfer_max_len(sc->sc_xfer[UMCT_BULK_DT_WR]);
usbd_transfer_start(sc->sc_xfer[UMCT_BULK_DT_WR]);
usbd_transfer_stop(sc->sc_xfer[UMCT_BULK_DT_WR]);