Article ID: 000087382 Last Reviewed: 01/01/2015

Warning: Variable ADV_NETLIST_OPT_SYNTH_USE_FITTER_INFO not supported. Refer to --help=flow for proper command-line form when enabling two-pass optimization, or use a tcl script


  • Quartus® II Subscription Edition

    This warning message will appear in the Quartus® II software version 3.0 if you enabled the "Use fitter timing information" Netlist Optimization in a previous version of the Quartus II software.


    The "Use fitter timing information" Netlist Optimization has been removed from the Quartus II user interface in version 3.0. Therefore, the ADV_NETLIST_OPT_SYNTH_USE_FITTER_INFO variable in your setttings file is no longer valid. The option will be ignored when running a compilation from the user interface and removed from the Compiler Settings File (.csf) by the Quartus II software.

    To run a compile where the synthesizer uses detailed timing information from the fitter, run the Two-Pass Optimization Flow from the command line or a script.

    This flow typically leads to a significant increase in compile time as compared to a regular compilation flow because the flow involves two compilations. The first compilation extracts timing information using the Fast Fit option, and the second compilation re-synthesizes the design using the extracted timing information from the fitter.

    The Two-Pass Optimization flow can be called directly using the following syntax:

    quartus_sh --flow two_pass_optimization <project> [-c <csf/ssf>]

    It can also be embedded in a Tcl script which can be run using the following command:

    quartus_sh -t <my_script>.tcl

    This Tcl script <my_script>.tcl should contain the following commands:


     package require ::quartus::flow project_open <project> execute_flow -two_pass_optimization project_close  

    For more details on Netlist Optimizations, refer to AN 198: Achieving Timing Closure Using Quartus II. (Link: /content/dam/altera-www/global/en_US/pdfs/literature/an/an198.pdf)