Honored Contributor
Honored ContributorI don't think I've seen any documentation on this. The slow model, which is the main one people use, basically models the worst possible delays. These are over PVT(Process, Voltate and Temperature). Setup failures are generally in this model. The Fast Model is the fastest the delays could be and is generally where hold violations occur. The middle model was added for 65nm, and shows something called Temperature Inversion, whereby not all delays follow a straight line in performance between the slow and fast model. Occasionlly you'll see failures in this model, but usually it's similar to the other two.
