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AR# 38620

ISE 12.2 Pack Virtex-6 - Pack:2784 - Directed packing was unable to obey the user design constraint


The following error is being received during Map:

ERROR:Pack:2784 - Directed packing was unable to obey the user design constraint
   st/pe_gen[3].natural_order_input.PE/delay_addr_bf2/SRL16_2) which requires
   combining the symbols listed below into a single SLICEM component.
The directed pack was not possible because:
   The top reasons for failure were:
           -> A legal placement was never found for shift register symbol
How can I resolve this error?


This is a known issue which has been resolved in ISE 12.3.

The issue can be worked around by disabling power optimization (Removing the -power switch) of Map.

AR# 38620
Date Created 10/14/2010
Last Updated 07/30/2014
Status Active
Type General Article
  • Virtex-6 CXT
  • Virtex-6 HXT
  • Virtex-6 LX
  • More
  • Virtex-6 LXT
  • Virtex-6 SXT
  • Less
  • ISE Design Suite - 12.1
  • ISE Design Suite - 12.2