ISE
Back-Annotating Pin Locations
You can run the Back-annotate Pin Locations process after you implement your design. The Back-annotate Pin Locations process runs the PIN2UCF program, which back-annotates pin locking constraints from a successfully placed and routed FPGA design to a User Constraints File (UCF). This process extracts pin locations and logical pad names from the NCD file and writes this information to an existing UCF. If a UCF does not exist in your project, a new file is created.
By default, PIN2UCF does not write conflicting constraints to a UCF. If user-specified constraints are exact matches of PIN2UCF generated constraints, a pound sign (#) is added in front of all matching user-specified location constraint statements. If PIN2UCF discovers conflicting constraints, it writes this information to the pinlock.rpt report file.
Note For more information about PIN2UCF, see the Command Line Tools User Guide.
To Back-Annotate Pin Locations
  1.  In the Design panel, select Implementation from the Design View drop-down list. Image
  2.  In the Hierarchy pane, select the top module Image.
  3.  In the Processes pane, expand Place & Route.
  4.  Optional. Right-click Back-Annotate Pin Locations, and select Process Properties to specify the UCF file name in the Back-Annotate Pin Locations dialog box.
  5.  Double-click Back-Annotate Pin Locations.
In the UCF file, pin locking constraints are written to a PINLOCK section. The PINLOCK section begins with the statement # PINLOCK BEGIN and ends with the statement #PINLOCK END. The pinout information is applied to all subsequent design implementation processes that you run.
Note This process updates the UCF and source file, so the design is no longer up-to-date. You must rerun Place & Route to update the design. To write the results to a temporary LPC file rather than to the UCF file, run the View Locked Pin Constraints process, as described in Viewing Locked Pin Constraints.
After running this process, you can perform any of the following:
  •  View the back-annotate pin report. Image
  •  Generate Post-Place & Route Static Timing. Image
  •  Run Generate Programming File. Image

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