Intel® Quartus® Prime Standard Edition User Guide: Design Compilation

ID 683283
Date 9/24/2018
Document Table of Contents

1.6.5. What Changes Initiate the Automatic Resynthesis of a Partition?

A partition is synthesized from its source files if there is no post-synthesis netlist available from a previous synthesis, or if the netlist type is set to Source File. Additionally, certain changes to a partition initiate an automatic resynthesis of the partition when the netlist type is Post Synthesis or Post-Fit. The software resynthesizes the partition in these cases to ensure that the design description matches the post‑place‑and‑route programming files.

The following list explains the changes that initiate a partition’s automatic resynthesis when the netlist type is set to Post-Synthesis or Post-Fit:

  • The device family setting has changed.
  • Any dependent source design file has changed.
  • The partition boundary was changed by an addition, removal, or change to the port boundaries of a partition (for example, a new partition has been defined for a lower‑level instance within this partition).
  • A dependent source file was compiled into a different library (so it has a different -library argument).
  • A dependent source file was added or removed; that is, the partition depends on a different set of source files.
  • The partition’s root instance has a different entity binding. In VHDL, an instance may be bound to a specific entity and architecture. If the target entity or architecture changes, it triggers resynthesis.
  • The partition has different parameters on its root hierarchy or on an internal AHDL hierarchy (AHDL automatically inherits parameters from its parent hierarchies). This occurs if you modified the parameters on the hierarchy directly, or if you modified them indirectly by changing the parameters in a parent design hierarchy.
  • You have moved the project and compiled database between a Windows and Linux system. Due to the differences in the way new line feeds are handled between the operating systems, the internal checksum algorithm may detect a design file change in this case.

The software reuses the post-synthesis results but re-fits the design if you change the device setting within the same device family. The software reuses the post-fitting netlist if you change only the device speed grade.

Synthesis and Fitter assignments, such as optimization settings, timing assignments, or Fitter location assignments including pin assignments, do not trigger automatic recompilation in the incremental compilation flow. To recompile a partition with new assignments, change the netlist type for that partition to one of the following:

  • Source File to recompile with all new settings
  • Post-Synthesis to recompile using existing synthesis results but new Fitter settings
  • Post-Fit with the Fitter Preservation Level set to Placement to rerun routing using existing placement results, but new routing settings (such as delay chain settings)

You can use the LogicLock Origin location assignment to change or fine-tune the previous Fitter results from a Post-Fit netlist.