Total Wire Length Calculation

[BOYANG ZHANG]

Howdy people in rapidwright,

I used Vivado to place my design and generate the post placement .dcp file and now I am tying to calculate the total wire length of my design.

But I cannot find a way to calculate the total wire length using vivado directly. I wonder if there is a way to calculate the total wire length by rapidwright?

Thank you for your help.

[RapidWright]

Although there are a number of ways to determine wire length, here is a brute force, naive attempt by just using a Manhattan Distance approach to each physical net's source pin to each sink pin.  This is probably pessimistic in the sense that nets with fan out greater than 1 will typically have some branching farther (reusing a path).  In this case the unit of length is the dimension size of a tile.  

public static void main(String[] args) {

Design d = Design.readCheckpoint("my_placed_design.dcp");

DesignTools.createMissingSitePinInsts(d);

int wireLength = 0;

for(Net n : d.getNets()) {

if(n.isClockNet() || n.isStaticNet()) continue;

SitePinInst src = n.getSource();

if(src == null) continue;

Tile srcTile = src.getTile();

for(SitePinInst sink : n.getSinkPins()) {

wireLength += sink.getTile().getManhattanDistance(srcTile);

}

}

System.out.println(wireLength);

}

[BOYANG ZHANG]

Thank you for your help!

But I don't see a method called"createMissingSitePinInsts()" in my DesignTools.java(but I do see it in the official java doc). Is there anything going wrong with my java package? Or is there another way to calculate it?

[RapidWright]

This method was written and committed somewhat recently, perhaps you just need to pull the latest changes (or just perform a clean in your sandbox):

https://github.com/Xilinx/RapidWright/blob/7719808796bf3e894124cb8fcbfaee66a2da15f9/src/com/xilinx/rapidwright/design/DesignTools.java#L1327

It was first added on July 28th, 2020, but there have been a few fixes since them.