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AR# 50535

14.1 System Generator - Design imported from Sysgen is failing to synthesise in ISE due to Errors processing TIMESPEC constraints


I have generated a HDL Netlist from within System Generator, and ported that design into Project Navigator.

I am receiving errors in XST stating that it cannot process timing constraints.

ERROR:Xst:1617 - Processing TIMESPEC TS_ce_200_b61e9f15_group_to_ce_200_b61e9f15_group: user TIMEGRP 'ce_200_b61e9f15_group' must be previously defined in FROM/TO constraint.
ERROR:Xst:1489 - Constraint annotation failed.

Is it possible to avoid these errors?


These constraints have been created with the HDL Netlist generation. 

These errors occur when these constraints are included in an XCF file added to the Project Navigator project for Synthesis. 

To avoid the issue, do not add the XCF to the Project Navigator project, and apply the constraints at NGDBuild/Translate stage using the UCF only.

This will allow XST to complete and the UCF constraints will be accurately applied to the post XST netlist.




AR# 50535
Date Created 06/21/2012
Last Updated 02/18/2015
Status Active
Type General Article
  • ISE Design Suite
  • System Generator for DSP