UMB_BULK_RX
usbd_transfer_start(sc->sc_xfer[UMB_BULK_RX]);
[UMB_BULK_RX] = {
config[UMB_BULK_RX].bufsize = UGETDW(np.dwNtbInMaxSize);
sc->sc_rx_bufsz = config[UMB_BULK_RX].bufsize;
usbd_transfer_stop(sc->sc_xfer[UMB_BULK_RX]);