The documentation does not state what the input angle units are.
From the IP GUI, it looks like they might be radians, even though 1.0000 = 2pi radians (or the signed equivalent) is a much better way to do a CORDIC, allowing a quick bit test for quadrant on angle inputs, and quick truncation of excess turns on arctan.
Are the units actually radians, where 3243F (b16) is 180 degrees?
When I find time, I will post something in detail. But one thing that the Altera design misses: One of the primary reasons people use a CORDIC is to get rid of the terribly difficult number "pi". Particularly in binary logic. It is actually not part of a CORDIC calculation unless someone makes it so.
A very clear description of CORDIC can be found here: http://dspguru.com/dsp/faqs/cordic/