Xilinx 8.2i manual Halting PAR

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Halting PAR

If you use this option, you may continue the PAR operation at a later time. To do this, you must look in the PAR report file to find the point at which you interrupted the PAR run. You can then run PAR on the output NCD file produced by the interrupted run, setting command line options to continue the run from the point at which it was interrupted.

Option 2 halt during routing may be helpful if you notice that the router is performing multiple passes without improvement, and it is obvious that the router is not going to achieve 100% completion. In this case, you may want to halt the operation before it ends and use the results to that point instead of waiting for PAR to end by itself.

•Option 3—this option stops the PAR run immediately. You do not get any output file for the current place/route iteration. You do, however, still have output files for previously completed place/route iterations.

•Option 4—this option is currently disabled.

•Option 5—Terminates current iteration if you have used the –n option and continues the next iteration.

Note: If you started the PAR operation as a background process on a workstation, you must bring the process to the foreground using the fg command before you can halt the PAR operation.

After you run PAR, you can use the FPGA Editor on the NCD file to examine and edit the results. You can also perform a static timing analysis using TRACE or the Timing Analyzer. When the design is routed to your satisfaction, you can input the resulting NCD file into the Xilinx Development System’s BitGen program. BitGen creates files that are used for downloading the design configuration to the target FPGA. For details on BitGen, see Chapter 14, “BitGen”.

Development System Reference Guide www.xilinx.com 195