When simulating the MIG v3.4 example design with the ISE software 12.1 simulation models using ModelSim PE, you may get the following error message:
# ** Error: (vsim-3601) Iteration limit reached at time 20313750 ps.
# Could not find any active process to start the loop analysis.
# Executing ONERROR command at macro ./sim.do line 140
This is due to a known issue in the simulation model which only affects Modelsim PE. If you are using Modelsim SE, you will not see this problem.
To work around the issue, you must download patched MCB.vp files here:
http://www.xilinx.com/txpatches/pub/swhelp/ise12_updates/cr561981.zip
To recompile the MCB secureIP model do the following:
1) Use any unzip utility to unarchive this file to a temporary location.
2) Once the files have been extracted run the below commands in Modelsim Console after changing dir to the location of he file extraction.
3) Vlog -work secureip -f mcb_cell.list.f
This is resolved in ISE software 12.2. If you are using ISE software 12.2 or later, you do not need this patch. If you are using ISE software 11.5 or earlier, you do not need this patch.
Note that you will have to recompile your simulation models after installing the ISE software 12.2 update.