Critical Issue
Description
This problem affects DDR3 products.
A simulation error can occur when you simulate a quarter-rate DDR3 design using VHDL and ModelSim, with Ping Pong PHY enabled and the calibration mode set to Quick or Full.
Resolution
The workaround for this issue is to do one of the following: set the calibration mode to Skip; use Verilog instead of VHDL; or use a different simulator.
This issue will be fixed in a future release.