USS820_REG_STRIDE
USS820_RXDAT * USS820_REG_STRIDE, (void *)&req, sizeof(req));
USS820_RXDAT * USS820_REG_STRIDE, buf_res.buffer, buf_res.length);
USS820_TXDAT * USS820_REG_STRIDE, buf_res.buffer, buf_res.length);
#ifndef USS820_REG_STRIDE
bus_space_read_1((sc)->sc_io_tag, (sc)->sc_io_hdl, (reg) * USS820_REG_STRIDE)
bus_space_write_1((sc)->sc_io_tag, (sc)->sc_io_hdl, (reg) * USS820_REG_STRIDE, (data))