Forum Discussion
I am - let's say surprised - by the fact that such slight details like supporting loops for BE in memory inference differing between the paid and the free version of Quartus. It's impossible for users to keep track of this...
However, technically you answered the question why inference does not work. The question now is how I shall proceed from here.
I am maintaining an Open Source FPGA Standard library - which according to GitHub stars belongs to the most popular ones around (see https://github.com/open-logic/open-logic). Of course I will document that RAM inference might not work for Quartus Standard. However, I would want to verify it to work with Quartus Pro. Would Altera be open to donate a Pro License to the Open Logic project for this purpose?
IMO this would be in the mutual interest of both sides: I'd like to verify RAM inference for Altera devices at least with Quartus Pro. If I do so, users probably are motivated to buy Quartus Pro which is in the interest of Altera.
BTW: I ran into other errors with True-Dual-Port RAM inference - but I guess I should try this one with Quartus Pro as well.