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AR# 60875

14.7 Pack - Control set connectivity of FF corrupted by Pack bug


The CE connectivity of Flip-flops can be corrupted by Pack when a Flip-flop (FF) is packed into the same slice as a RAM/SRL BEL with different CE connectivity and the FF is placed in a 5FF BEL with no FFBELs used.

This is a rare occurrence as the FF BEL is the first choice for placement.

Use of the 5FF BEL can be a consequence of the use of the LUT Combining feature (-lc auto) but the bug is not directly related to that feature.


The patch attached to this Answer Record has been made available for ISE 14.7.

To install on Linux, use the commands below:

tar zxvf 60875_pack_147_lin64.tar.gz

To install on Windows, unzip the file "60875_pack_147_win64.zip" in the %XILINX% install directory while maintaining directory structure.

Note: A new rev2 version of the win64 patch was added in December 2015 when it was discovered that some Spartan-6 libraries were missing from the original patch.

No change was needed for the Linux patch.


Associated Attachments

Name File Size File Type
60875_pack_147_lin64.tar.gz 506 KB GZ
60875_pack_147_win64_rev2.zip 428 KB ZIP
AR# 60875
Date 12/22/2015
Status Active
Type General Article
  • Virtex-6
  • Spartan-6
  • ISE Design Suite - 14