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AR# 47880

MIG DDR2/DDR3- ERROR: Memory overflow. You must increase the MEM_BITS parameter or define MAX_MEM


Why do I get the following errorwhile simulating my MIG design?

ERROR: Memory overflow.Write to Address 000400 with Data xxxxxxxx1f1b1713 will be lost.

# You must increase the MEM_BITS parameter or define MAX_MEM.


This error is due to limitation in the Micron memory model which sets MEM_BITS equal to 10 by default.You will find MAX_MEM mentioned in the model, but you will need to set it ito a proper value n the *.vh file located in the ./sim directory,or you can set this via command line using one of the following examples:

simulator command line
--------- ------------
ModelSim vsim -MEM_BITS=8 <memory_model>
NC-Verilog ncverilog +defparam+ <memory_model>.MEM_BITS=8 ddr2.v
VCS vcs -pvalue+MEM_BITS=8 <memory_model>.v

AR# 47880
Date Created 05/14/2012
Last Updated 05/20/2012
Status Active
Type 14;#
  • Virtex-5 FXT
  • Kintex-7
  • Virtex-6 CXT
  • More
  • Virtex-6 HXT
  • Virtex-6 LX
  • Virtex-6 LXT
  • Virtex-6 SXT
  • Virtex-7
  • Less
  • ISE Design Suite - 13.3
  • MIG
  • MIG 7 Series
  • MIG Virtex-6 and Spartan-6