fully route design report site pin not routed in RapidWright

[coherent17]

Hi Rapidwright Experts,

As we discussed in the last discussion sessions, the suggested method to get the route fail net are discussed in 1152.

For the fully routed design from Vivado, the below code snippet still report some nets are not fully routed:

public class ReadDCP {
    public static void main(String[] args) {
        if (args.length != 2) {
            System.out.println("USAGE: <input DCP> <input EDIF>");
            return;
        }

        System.out.println("Reading DCP file: " + args[0]);
        System.out.println("Reading EDIF file: " + args[1]);
        Design design = Design.readCheckpoint(args[0], args[1]);
        DesignTools.updatePinsIsRouted(design);
        DesignTools.makePhysNetNamesConsistent(design);
        DesignTools.createMissingSitePinInsts(design);


        System.out.println("Device: " + design.getDevice().getName());
        System.out.println("Cells: " + design.getCells().size());
        System.out.println("Nets: " + design.getNets().size());


        System.out.println("Checking for not fully routed nets");
        int notFullyRoutedNetCount = 0;
        int fullyRoutedNetCount = 0;
        for (Net n : design.getNets()) {
            if(!n.hasPIPs()) continue;
            boolean isFullyRouted = true;
            for(SitePinInst p : n.getPins()) {
                if(!p.isRouted()) {
                    notFullyRoutedNetCount++;
                    System.out.println("Net " + n.getName() + " is not fully routed.");
                    isFullyRouted = false;
                    break;
                }
            }
            if (isFullyRouted) {
                fullyRoutedNetCount++;
            }
        }
        System.out.println("Number of nets not fully routed: " + notFullyRoutedNetCount);
        System.out.println("Number of nets fully routed: " + fullyRoutedNetCount);
    }
}

Rapidwright stdout:

Vivado report route status:

The total net(fully routed + not fully routed) in Rapidwright have the same amount as Vivado report in # of routable nets. But the above code snippet false alarm some of the nets that is fully routed in Vivado. Any suggestion to modify the code to help the result align the Vivado report_route_status?

Thanks!!

[clavin-xlnx]

The problem is likely due to counting dual-output SitePinInst that are present on the net but not necessarily needed to be fully routed. For example:

There might be two source (OUTPUT) SitePinInst on this net, D_O and DMUX. However, the router only chose to use DMUX to provide all the connectivity for the net. You can avoid counting this situation by ensuring that you are only looking at all the sink (INPUT) pins to be routed:

...
            for(SitePinInst p : n.getPins()) {
                if(!p.isOutPin() && !p.isRouted()) {
                    notFullyRoutedNetCount++;

...

[coherent17]

Hi Chris, thanks for the suggestion!
This removes lots of the false alarm on the fully routed net, but still some nets are being false alarm:

The SitePinInst named AX on the BEL Pin of CARRY8 still be reported as not routed input pin, is there any way to work around on this situation?
I can do pin name matching to skip the check for the AX pin, but is there a better way to resolve this problem?

code snippet:

        for (Net n : design.getNets()) {
            if(!n.hasPIPs()) continue;
            boolean isFullyRouted = true;
            for(SitePinInst p : n.getPins()) {
                if(!p.isOutPin() && !p.isRouted()) {
                    // if (p.getName().contains("AX")) continue;
                    notFullyRoutedNetCount++;
                    System.out.println("Net *** " + p.getName() + " is not fully routed.");
                    isFullyRouted = false;
                    break;
                }
            }
            if (isFullyRouted) {
                fullyRoutedNetCount++;
            }
        }

Thanks!

[coherent17]

Hi Chris, thanks for the suggestion! This removes lots of the false alarm on the fully routed net, but still some nets are being false alarm:

The SitePinInst named AX on the BEL Pin of CARRY8 still be reported as not routed input pin, is there any way to work around on this situation? I can do pin name matching to skip the check for the AX pin, but is there a better way to resolve this problem?

code snippet:

        for (Net n : design.getNets()) {
            if(!n.hasPIPs()) continue;
            boolean isFullyRouted = true;
            for(SitePinInst p : n.getPins()) {
                if(!p.isOutPin() && !p.isRouted()) {
                    // if (p.getName().contains("AX")) continue;
                    notFullyRoutedNetCount++;
                    System.out.println("Net *** " + p.getName() + " is not fully routed.");
                    isFullyRouted = false;
                    break;
                }
            }
            if (isFullyRouted) {
                fullyRoutedNetCount++;
            }
        }

Thanks!

Found out the root cause is the DesignTool setting order:

Original:

        DesignTools.updatePinsIsRouted(design);
        DesignTools.makePhysNetNamesConsistent(design);
        DesignTools.createMissingSitePinInsts(design);

After:

        DesignTools.makePhysNetNamesConsistent(design);
        DesignTools.createMissingSitePinInsts(design);
        DesignTools.updatePinsIsRouted(design);

Does DesignTools.updatePinsIsRouted(design) need to come after the previous 2 lines of code?
Thanks!

[clavin-xlnx]

The "After" ordering makes the most sense and is probably the best way to proceed here. Thanks for updating your response!

[coherent17]

Hi Chris, thanks for confirmation!