What's the reason rejecting register duplication? - What's the reason rejecting register duplication? I'm trying to manually duplicate a register with the following assignment: set_instance_assignment -name DUPLICATE_REGISTER -to *is_all_mt_veri_not_empty* As shown in the figure, the duplication is rejected with the reason "synchronization register". I was wondering what's the meaning of this reason? I did not find any document elaborating the reason more detailedly. Thank you. Replies: Re: What's the reason rejecting register duplication? May I know if there is any update? Replies: Re: What's the reason rejecting register duplication? Hi Yu, The reason mean your register is one of the synchronizer chain for CDC thus it prevent reg duplication. Replies: Re: What's the reason rejecting register duplication? If the register was detected as one that's part of a synchronization chain between clock domains, that would prevent duplication in this way.