ISE
Analyzing Timing and Floorplanning a Design — Post-Implementation
You can use the PlanAhead™ software to analyze your design and manually or automatically place logic. Floorplanning is an optional methodology that you can use to improve the performance of your design by constraining critical paths or adjusting the automatic placement. Floorplanning can be useful for structured designs and data path logic.
Constraints are saved to a user constraints file User Constraints File (UCF). You can create the UCF file prior to running this process, as described in Creating a Source File, or you can allow the software to create an empty UCF file.
Note This process is not supported for CPLDs.
To Analyze Timing and Floorplan a Design — Post-Implementation
  1.  In the Design panel, select Implementation from the Design View drop-down list. Image
  2.  In the Hierarchy pane, select either the top module Image or the associated UCF.
  3.  In the Processes pane, expand Place & Route.
  4.  Double-click the Analyze Timing/Floorplan Design (PlanAhead) process.
The PlanAhead software opens. Project Navigator passes the placed source files to the PlanAhead software. If a UCF file is associated with your ISE® project, it is passed to the PlanAhead software for modification. If a UCF file does not exist, an empty one is created for you. If multiple UCF files exist, you are prompted to select the file to which you want to add new constraints. Existing constraints are modified in their respective files. For more information, see the “Analyzing the Design,” “Analyzing Implementation Results,” and Floorplanning the Design” chapters of the PlanAhead User Guide.
Note After updating constraints in the PlanAhead software, you must save the PlanAhead project and exit the PlanAhead software. This updates the UCF files in the ISE project and updates the ISE project status accordingly. If you do not save and exit from the PlanAhead software, the ISE project and UCF files are not updated.
After running this process, you can do the following:
  •  Analyze power consumption. Image
  •  Generate a post-place and route simulation model. Image
  •  Rerun the Implement Design process. Image

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