Honored ContributorI have generated a workable program file for cycloneii c8 speed grade device. In my new design, i want to used c6 device. Will that program file work on c6 device.
Actually, I want to know what does speed grade mean for Cyclone series devices?
Honored ContributorHi,
Officially and generally, you should compile with the chosen device and speed as timing margins are different. Unofficially, it may work. As to speed grades, the rumours are that after coming out of fabrication factory the devices are grouped according to how bad(sorry, how good) they perform into such grades... KazHonored ContributorIt should work, and not just "unofficially", but "officially". That's why the fast timing models are the same for all speed grades. Just make sure you are performing multicorner timing analysis.
Honored ContributorAs the come out of the FAB, the devices all run at slightly different speeds, and get "binned" as different devices. In the software, these bins are modeled as speed grades. They are modeled between two operating conditions, the fast model, which is the fastest a device will run(and accounts not just for the fastest Process out of the FAB, but the fastest Voltage and Temperature operating conditions within spec, which is just PVT). The fast model is common across all speed grades. The other model, the slow model, varies across speed grade, getting slower with the higher number. Note that it's possible that as the process gets better, the FAB may produce more and more of the faster parts, but if there is demand for slower parts, they can be marked as slower parts and shipped that way. The speed grade just means that's the slowest they could be, but they could be faster. So yes, it should be fine in the faster speed grade, but if you meet timing in the slower speed grade, you might as well buy the cheaper part.
Honored ContributorThank you very much.
