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CLOCKS_ARE_SYNCHRONIZED Warning

Altera_Forum
Honored Contributor II
‎11-08-2010 10:27 AM
2,288 Views

I have this warning  

Warning: Assertion warning: Number of metastability protection registers is not specified. Based on the parameter value CLOCKS_ARE_SYNCHRONIZED=FALSE, the synchronization register chain length between read and write clock domains will be 2 

 

I don't know where to set the synchronization chain number in the GUI, I did set the Synchronization Register Chain length to 2 in the Analysis & Synthesis Settings window but it doesn't seem to be OK...:confused::confused: 

 

Thank you for your help!
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Altera_Forum
Honored Contributor II
‎11-08-2010 12:38 PM
1,289 Views

I presume that warning refers to a specific module/function you're using. 

It's a bit hard to give any advice without knowing what it is.
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Altera_Forum
Honored Contributor II
‎11-08-2010 01:04 PM
1,289 Views

When locating it in design file, it appears that the warning refers to a dcfifo_hrd1 subdesign file which has a set of "local" altera options on top ( OPTIONS ALTERA_INTERNAL_OPTION = "AUTO_SHIFT_REGISTER_RECOGNITION=OFF;REMOVE_DUPLICATE_REGISTERS=OFF;suppress_da_rule_internal=d101;suppress_da_rule_internal=d102;suppress_da_rule_internal=s102;{-to p0addr} POWER_UP_LEVEL=LOW;{-to rdptr_g} suppress_da_rule_internal=r105"; ). 

 

Thank you
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