udc_write_hwep
udc_write_hwep(udc, EP_IN, NULL, 0);
udc_write_hwep(udc, EP_IN, (req->req.buf + req->req.actual), ts);
udc_write_hwep(udc, ep->hwep_num, NULL, 0);
udc_write_hwep(udc, EP_IN, &ep0buff, 2);