About Place & Route


The Quartus II Fitter, which is also known as the PowerFit Fitter, performs place and route, also referred to as "fitting" in the Quartus II software. Using the database that has been created by Analysis & Synthesis, the Fitter matches the logic and timing requirements of the project with the available resources of a device. The Fitter assigns each logic function to the best logic cell location for routing and timing, and selects appropriate interconnection paths and pin assignments.

If you have made resource assignments in your design, the Fitter attempts to match those resource assignments with the resources on the devices, tries to meet any other constraints you may have set, and then attempts to optimize the remaining logic in the design. If you have not set any constraints on the design, the Fitter automatically optimizes it. If it cannot find a fit, the Fitter terminates compilation and issues an error message.

You can start a full compilation in the Quartus II software, which includes the Fitter module, or you can start the Fitter separately. You must run Analysis & Synthesis successfully before starting the Fitter separately.


ExpandPlace & Route Flow:

ExpandOptimizing the Fit:

ExpandPreserving Assignments through Back-Annotation:

 About Incremental Compilation


Scripting Information

Executable: quartus_fit


You can run the Fitter separately at the command prompt or in a script with the quartus_fit executable. You must run the Analysis & Synthesis executable quartus_map before running the Fitter. The quartus_fit executable creates a separate text-based report file that can be viewed with any text editor.


More information is available on the Compiler on the Altera website.



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