SDRAM Framebuffer with two asynchronous clocks

If you don't have any other signal that is crossing the clock domains then you shouldn't have to do a lot in Timequest. You are right that is base_address is constant you don't need to do anything with it either.

You should at least declare your clocks in Timequest to be sure everything is ok. A Cyclone IV is usually capable of handling signals at 100MHz, but the fitter needs to know this to be sure the time constraints are met.

The official Timequest documentation isn't very easy to read and use, but you can use instead rsyc's great user guide on the wiki (http://www.alterawiki.com/wiki/timequest_user_guide)