Exception: "Failed to find cell macro OBUFTDS ..." when reading a checkpoint

[harnhua]

Hi,

While reading an Ultrascale DCP using Design.readCheckpoint(<dcp_file>, <edif_file>), the following error occurred:

Exception in thread "main" java.lang.RuntimeException: failed to find cell macro OBUFTDS, we are in hdi_primitives
        at com.xilinx.rapidwright.edif.EDIFNetlist.expandMacroUnisims(EDIFNetlist.java:1579)
        at b.a(Unknown Source)
        at com.xilinx.rapidwright.design.Design.readCheckpoint(Unknown Source)
        at com.xilinx.rapidwright.examples.test.main(test.java:327)

The relevant lines in EDIFNetlist.java:

            public void expandMacroUnisims(Series series) {
                ...
                EDIFCell newCell = netlistPrims.getCell(cellName);
                if (newCell == null) {
(line 1579) -->     throw new RuntimeException("failed to find cell macro "+cellName+", we are in "+lib.getName());
                }

With the RapidWright team's help, I managed to resolve the issue with their help and would like to document the solution in this thread in case it is helpful.

Thanks,
Harnhua

[harnhua]

I was advised to check the following:

The line of code throwing the exception cannot find OBUFTDS in the primitives library.
Could you check the EDIF file to ensure that the OBUFTDS cell is in the primitives library?
You could run the follow egrep command to check quickly:

egrep 'Library |cell OBUFTDS' <your_edif_file>.edf

The output would look like:

(Library hdi_primitives
  (cell OBUFTDS (celltype GENERIC)
(Library work

In addition, other things to verify:

• Can you share the IOStandard used in relationship with the OBUFTDS primitive in use?
• Is the OBUFTDS cell a leaf cell? If not, what cell types are its children instances?
• What is the parent cell type if it is a Xilinx-primitive/macro? (not interested if it is a user-cell)

Finally, steps to make sure that I had the latest RapidWright codebase:

Be sure to pull in the latest code from the GitHub Xilinx/RapidWright repo.

1. In the RapidWright directory, run “gradlew update_jars”
2. Run “rm -rf data/*” # We now download data files on-demand, no need to download the large zip file anymore
3. Run “gradlew clean”
4. Run “gradlew compileJava”
5. Alternatively, you could also try cloning a new copy and try afresh

[harnhua]

It turned out that OBUFTDS was not found in the EDIF file.

With that information, Chris and his team quickly got to the bottom of things and produced pull request #304
I pulled the fix and verified that it works as expected now.

Thanks again for all the help.

Cheers,
Harnhua