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AR# 16931

5.2i PAR and LogiCORE XFFT v2.0, ReedSolomon v4.0, Interleaver v2.0 - Why do I receive a PAR warning about the placement constraints when the "Create RPM" option is selected?

Description

Why do I receive a PAR warning about the placement constraints when the "Create RPM" option is selected? 

 

The following warning is displayed: 

"WARNING:Place -  

The structured logic associated with a carry chain could not be placed in 

such a way as to use all of the fast carry connections due to a placement 

constraint. A sub-optimal placement will be performed which may result in 

timing errors. You will need to verify that this sub-optimal placement will 

be satisfactory and that the resulting performance is acceptable."

Solution

This is a known problem that will be fixed in the 6.1i design tools release. 

 

For a detailed list of LogiCORE Fast Fourier Transform (FFT) Release Notes and Known Issues, see (Xilinx Answer 29209)

For a detailed list of LogiCORE Interleaver/De-Interleaver Release Notes and Known Issues, see (Xilinx Answer 30174)

For a detailed list of LogiCORE Reed Solomon Decoder Release Notes and Known Issues, see (Xilinx Answer 30176)

For a detailed list of LogiCORE Reed Solomon Encoder Release Notes and Known Issues, see (Xilinx Answer 30177).

AR# 16931
Date Created 09/03/2007
Last Updated 05/15/2014
Status Archive
Type General Article