Description
You will see the following warnings when trying to simulate a DDR3 SDRAM UniPHY based controller generated in Quartus II software version prior to 11.1 with vendor memory model:
# {hierarchy path}.cmd_task at time 50005156.0 ps WARNING: 500 us is required after RST_N goes inactive before CKE goes active.
# {hierarchy path}.reset at time 50027031.0 ps WARNING: 200 us is required before RST_N goes inactive.
Resolution
This is due to skip and quick calibration option in the megawizard which will not simulate the full required times for initialization and calibration.
From Quartus® II software version 11.1 onwards, there is an option for full calibration which will eliminate these warnings.