Partial Reconfiguration in DE2

I apologise for not being clear at first, but that "soft reconfiguration" idea was my original intent for the post. Sorry if the idea was perceived differently.

Well, I don't know how you'd like to call it, so I just dubbed it "soft partial reconfiguration", but you can give that block your own name as well... It's the basic idea that I wished to explain.

Perhaps the term "configurable design" is less confusing.

Yes, logic resources is a concern. You have to figure out if you have enough resources to implement this block. This depends on how "big" your user configuration file is... if it's just a few bytes, you can simple use the device's registers, otherwise if it's a few kB (or even 1kB), you can consider using internal RAM blocks. I'm not sure which Cyclone II device you're using... but I assumed you have enough resources to implement this sort of thing (my assumption could be wrong, so it's better to check if you have enough resources).

I'm not too sure, but maybe you may need about <3 kLEs (this is pessimistic, you can make it much less than that), with some memory (memory depends on how big your user settings file is).

You can try to optimise your HDL for space, so it uses the least LEs as possible, and more memory instead (here, I'm assuming you have a lot of memory).

But anyway, FvM's concerns are valid, you need to think about those as well.