https://www.ics.uci.edu/~jmoorkan/vhdlref/
https://www.nandland.com/vhdl/tutorials/index.html
https://www.intel.com/content/www/us/en/programmable/support/training/course/ohdl1110.html
https://www.digikey.com/eewiki/pages/viewpage.action?pageId=20939345
https://eewiki.net/pages/viewpage.action?pageId=4096079
https://eewiki.net/pages/viewpage.action?pageId=20939345
https://www.digikey.com/eewiki/pages/viewpage.action?pageId=4096117
http://hamblen.ece.gatech.edu/DE2/
http://esd.cs.ucr.edu/labs/tutorial/
http://www.seas.upenn.edu/~ese171/vhdl/vhdl_primer.html
http://www.altera.com/education/training/courses/OHDL1110
https://www.youtube.com/watch?v=CIImbDyJ7W4
