## LICENSE
BSD I guess...(fix me)
+## Useful resources
+
+![UTMI_interface](https://www.crifan.com/files/pic/serial_story/other_site/p_blog_bb.JPG)
+
+![UTMI+levels](https://www.crifan.com/files/pic/serial_story/other_site/p_blog_aa.JPG)
+
+![UTMI+level3_interface](https://www.crifan.com/files/pic/serial_story/other_site/p_blog_cc.JPG)
+
+![LPI_signals](https://www.crifan.com/files/pic/serial_story/other_site/p_blog_dd.JPG)
+
+![LPI_signals_table](https://www.crifan.com/files/pic/serial_story/other_site/p_blog_dd.JPG)
+
## reference
* <https://opencores.org/project,ulpi_wrapper> (GPL'd)
* <https://github.com/mossmann/daisho/blob/master/sw/fpga/common/usb3/usb2_ulpi.v> (BSD)