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AR# 52947

Vivado Constraints - When are IP core constraints processed relative to my project constraints?

Description

According to UG903, Vivado applies IP constraints after applying user constraints.

If you use the native IPs that come with a constraint file, the IP XDC files are loaded after your files, in the same sequence as the IPs are listed in the IP Sources window, unless the file PROCESSING_ORDER properties are set to LATE.

This has the effect of giving the IP higher priority than the user constraints.

Is there a way to overwrite the precedence?

How does PROCESSING_ORDER property affect the constraints processing sequence?

Solution

You can change the PROCESSING_ORDER property of your XDC file as follows:
 
  1. Highlight the XDC file in your Sources view.
  2. Open the Attributes tab in the Source File Properties window.
  3. Change the PROCESSING_ORDER of the XDC to EARLY, NORMAL, or LATE, depending on when you want the file to be processed.


Remember, the last constraint applied takes precedence.

For more information about the PROCESSING_ORDER property, please refer to UG903.

AR# 52947
Date 09/22/2014
Status Active
Type General Article
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