Answers Database

M1.4 PAR, TRCE, Timing - How to invoke the "KPATHS" timing algorithm.


Record #3773

Product Family:  Software

Product Line:  FPGA Implementation

Problem Title:
M1.4 PAR, TRCE, Timing - How to invoke the "KPATHS" timing algorithm.


Problem Description:
M1.4 has a new experimental timing algorithm (KPATHS)
available as an alternative to the default algorithm.
It speeds up timing analysis dramatically, especially
on designs that are getting bogged down while using the
conventional timing algorithm and are displaying messages
refering to the PATH_LIMIT variable.

Note: This timing algorithm should not be used on designs
taht use offset constraints as they will be ignored.


Solution 1:

The KPATHS timing algoritm is enabled by setting the
following environment variable:

  setenv XILINX_GRAPHIMP KPATHS (work stations)
  set  XILINX_GRAPHIMP = KPATHS (PCs)

When the KPATHS algorithm is being used, PAR and TRCE
will output the following message:

  "Invoking connection based timing analysis"



End of Record #3773