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AR# 35927

11.x XST - "WARNING:HDLParsers:3571 - A circular dependency was detected."


The following warning occurs during synthesis:

"WARNING:HDLParsers:3571 - A circular dependency was detected."

What does this warning mean and can I safely ignore it?


This warning can occur in the following situations:
  • componentA.vhd requires design unit packageA which is provided by packageA.vhd
  • packageA.vhd requires library libB which includes componentB.vhd
  • componentB.vhd requires library libA which includes componentA.vhd

This is a valid approach for which the warning can be ignored.

This warning is not printed out when using XST for Virtex-6 and Spartan-6 devices.
AR# 35927
Date Created 06/02/2010
Last Updated 12/15/2012
Status Active
Type General Article
  • ISE Design Suite - 11.1
  • ISE Design Suite - 11.2
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