UBSER_BULK_DT_WR
[UBSER_BULK_DT_WR] = {
sc->sc_tx_size = usbd_xfer_max_len(sc->sc_xfer[UBSER_BULK_DT_WR]);
usbd_xfer_set_stall(sc->sc_xfer[UBSER_BULK_DT_WR]);
usbd_transfer_start(sc->sc_xfer[UBSER_BULK_DT_WR]);
usbd_transfer_stop(sc->sc_xfer[UBSER_BULK_DT_WR]);