Quartus® Prime Standard Edition User Guide: Design Compilation

ID 683283
Date 10/22/2021
Document Table of Contents Providing Information About the Top-Level Framework

If this design flow is not possible, you can generate partition-specific scripts for individual designs to provide information about the top-level project framework with these steps:
  1. In the top-level design, on the Project menu, click Generate Design Partition Scripts, or launch the script generator from Tcl or the command line.
  2. If lower-level projects have already been created for each partition, you can turn off the Create lower-level project if one does not exist option.
  3. Make additional changes to the default script options, as necessary. Altera recommends that you pass all the default constraints, including LogicLock regions, for all partitions and virtual pin location assignments. Altera also recommends that you add a maximum delay timing constraint for the virtual I/O connections in each partition.
  4. The Quartus® Prime software generates Tcl scripts for all partitions, but in this scenario, you would focus on the partitions that make up the cross-partition critical paths. The following assignments are important in the script:
    • Virtual pin assignments for module pins not connected to device I/O ports in the top-level design.
    • Location constraints for the virtual pins that reflect the initial top-level placement of the pin’s source or destination. These help make the lower-level placement “aware” of its surroundings in the top-level design, leading to a greater chance of timing closure during integration at the top level.
    • INPUT_MAX_DELAY and OUTPUT_MAX_DELAY timing constraints on the paths to and from the I/O pins of the partition. These constrain the pins to optimize the timing paths to and from the pins.
  5. The partition designers source the file provided by the project lead.
    • To source the Tcl script from the Quartus® Prime GUI, on the Tools menu, click Utility Windows and open the Tcl console. Navigate to the script’s directory, and type the following command:

      source <filename>

    • To source the Tcl script at the system command prompt, type the following command:

      quartus_cdb -t <filename>.tcl

  6. The partition designers recompile their designs with the new project information or assignments and optimize as needed. When the results are satisfactory and the timing requirements are met, export the updated partition as a .qxp.
    The project lead obtains the updated .qxp files from the partition designers and adds them to the top-level design. When a new .qxp is added to the files list, the software will detect the change in the “source file” and use the new .qxp results during the next compilation. If the project uses the advanced import flow, the project lead must perform another import of the new .qxp.
    You can now analyze the design to determine whether the timing requirements have been achieved. Because the partitions were compiled with more information about connectivity at the top level, it is more likely that the inter‑partition paths have improved placement which helps to meet the timing requirements.