Quartus® Prime Pro Edition User Guide: Design Compilation

ID 683236
Date 9/30/2024
Public
Document Table of Contents

2.5.2. Changing Fitter Aggressive Routability Optimization Settings

Fitter Aggressive Routability Optimization determines the degree to which the Fitter prioritizes routability during the FPGA place and route process. The Fitter Aggressive Routability Optimization setting can take the following values:
  • Automatically: The Fitter dynamically decides whether aggressive routability optimizations are beneficial for the design.
  • Always: The Fitter ensures consistent application of aggressive routability optimizations in every compilation, potentially reducing routing wire usage and time at the expense of design speed.
  • Never: Disables these optimizations entirely.
The default value for the Fitter Aggressive Routability Optimization setting is Automatically. If you observe multiple routing iterations or lengthy runtimes, try setting the value to Always. However, setting the value to Always does not guarantee a reduction in compilation time. If you do not see a benefit, revert the setting to Automatically.

The Fitter Aggressive Routability Optimization setting is accessible by clicking Advanced Settings (Fitter) in the Compiler Settings page of the Settings dialog box:

Alternatively, you can set the Fitter Aggressive Routability Optimization value through a QSF assignment with the following syntax:
set_global_assignment -name FITTER_AGGRESSIVE_ROUTABILITY_OPTIMIZATION <setting>
where <setting> is one of the following values:
  • ALWAYS
  • AUTOMATICALLY
  • NEVER