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AR# 35389

12.1 CORE Generator - Setting JAVA memory size from CORE Generator interface does not work


I open the CORE Generator preferences by selecting select File -> Preferences, then I select Java and change the "Memory Available for Java" to one of the five standard values or any custom value. 

However, the amount of memory allocated for Java processes remains the same.

This can lead to:
  • Running out of Memory during core generation if the default setting is too small for a particular IP core.
  • An "Unable to create Java Virtual Machine" error if the system cannot allocate the default amount of memory.


The Java memory allocation setting in the CORE Generator preferences is not working correctly in ISE Design Suite 12.1.

To work around this issue, the CORE Generator tool should be invoked using the "coregen -J Xmx" option from the command line: 
coregen -J Xmx####m 

where "####" represents the number of Megabytes of memory to allocate.

 coregen -J Xmx384m  
coregen -J Xmx256m  
coregen -J Xmx1234m  
coregen -J Xmx2056m 

The JAVA_TOOL_OPTIONS environment variable could also be used to set the JAVA memory heap size.

For example:


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AR# 35389
Date Created 04/26/2010
Last Updated 10/10/2014
Status Active
Type General Article
  • ISE Design Suite - 12.1