de1-soc tutorial

I made up a short tutorial on integrating the SDC file for the De1-soc. It is a follow on from the sdram tutorial.

By no means am I am expert, but it might help people that are learning about timing constraints. Feedback would be nice (especially from people that can validate the approach).

[video=youtube;b4STwjT_g1g]https://www.youtube.com/watch?v=b4STwjT_g1g[/video]