The AWGN is targeted up to Virtex-4. Is it possible to port this to Virtex-5?
The AWGN Core has been developed as a Relationally Placed Macro (RPM) targeting Virtex-II, Virtex-II Pro, Spartan-3 and Virtex-4.
If you are targeting Virtex-5, you must modify the source code by commenting out all location constraints (RLOCs, LOCs, BELs, etc.). However, as the core is now not relationally placed, there will be a reduction in performance.
Please see (Xilinx Answer 30171) for a detailed list of LogiCORE Additive White Gaussian Noise Generator (AWGN) Release Notes and Known Issues.