CLOCKS_ARE_SYNCHRONIZED Warning

Altera_Forum · ‎11-08-2010

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!

Altera_Forum · ‎11-08-2010

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.

Altera_Forum · ‎11-08-2010

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