UDL_BULK_WRITE_0
[UDL_BULK_WRITE_0] = {
usbd_transfer_start(sc->sc_xfer[UDL_BULK_WRITE_0]);
usbd_xfer_set_priv(sc->sc_xfer[UDL_BULK_WRITE_0], &sc->sc_xfer_head[0]);
usbd_transfer_start(sc->sc_xfer[UDL_BULK_WRITE_0]);