For a complete list of simulation debug steps for Virtex-6 DDR3/DDR2 designs please refer to the "Debugging Virtex-6 FPGA DDR2/DDR3 SDRAM Designs"=>"Simulation Debug" section of UG406:
For steps on simulating the example design for Virtex-6 DDR3/DDR2 designs please refer to the "Getting Started"=>"Quick Start Example Design" section of UG406:
For information on why writes on the DDR interface contain more data than requested from the user interface, please see:
For information on Debugging issues with a User Design Simulation, please see: