Following are a few examples of PAR command lines and a description of what each does.
Example 1
The following command places and routes the design in the file input.ncd and writes the placed and routed design to output.ncd.
par input.ncd output.ncd
Example 2
The following command skips the placement phase and preserves all routing information without locking it (re-entrant routing). Then it runs up to 999 passes of the router or stops upon completion and conformance to timing constraints found in the pref.pcf file. Then it runs three delay-based cleanup router passes. If the design is already completely routed, the effect of this command is to just run three delay-based cleanup passes.
par -k -i 999 -c 0 -d 3 input.ncd output.ncd pref.pcf
Example 3
The following command runs 20 place and route iterations at overall effort level 3. The mapping of the overall level (-ol) to placer effort level (-pl) and router effort level (-rl) depends on the device to which the design was mapped, and placer level and router level do not necessarily have the same value. The iterations begin at cost table entry 5. Only the best 3 output design files are saved. The output design files (in NCD format) are placed into a directory called results.dir.
par -n 20 -ol 3 -t 5 -s 3 input.ncd results.dir
Now, if you wanted to run two passes of cost-based and delay-based cleanup on the three designs saved (without running placement), you would enter this command for each design.
par -k -i 0 -c 2 -d 2 input.ncd output.ncd
Example 4
The following command copies the input design to the output design. The placement and routing phases are skipped completely. Since a delay file is generated as a result of the command, you can use these options to check the delay times in your design without having PAR change any of the design's placement or routing.
par -pr input.ncd output.ncd
Example 5
The following command allows re-entrant routing. Use this command when your design is only partially routed and you want to complete it or when the design does not meet your timing constraints and additional routing passes are needed to meet the constraints. Placement and placement optimization are skipped. In this case up to 30 router passes are run (you could run up to 2000). This may result in local rip-up and reroute if 20 router passes are run with no progress.
par -k -i 30 input.ncd output.ncd
Example 6
The following command gives you a delay report for a placed and routed file without modifying the file.
par -pwr input.ncd input.ncd
Example 7
The following command runs PAR (using the Turns Engine) on all nodes listed in the file named “allnodes”. It runs 10 place and route passes at placer effort level 3 and router effort level 2 on the file “mydesign.ncd”. It runs one cost-based cleanup pass of the router.
par -m allnodes -pl 3 -rl 2 -n 10 -i 10 -c l mydesign.ncd output.dir
