Scoreboard user guide?

[Martin Roenne]

Is there a userguide in pdf format for the Scoreboard? I can not find it in the download section.

[Eilert Backhus]

Hi,
have you read the “Functional Coverage using CoveragePkg” paper?
There you find explanations about functions like GetBinVal or CountCovHoles etc.
In other words, all the functions you need to examine the scoreboard are described there.
How you are dealing with this information depends on the way you designed your Testbench.

Is there anything else you are missing about using the scoreboard?

Have a nice simulation
Eilert

[Martin Roenne]

Hi Eilert, and thanks for your answer. The functions you are referring to are part of the coverage package, which only keeps track of what is tested, and not if the response was correct or not.

The scoreboard checks the responses from the DUT and compares to a reference value. I am looking for a userguide for the scoreboard package in pdf format. I do have the printed training material, but it is very inconvenient to carry around. That’s why 🙂

Regards Martin

[Eilert Backhus]

Hi Martin,
these are the OSVVM packages:
AlertLogPkg.vhd MemoryPkg.vhd NamePkg.vhd OsvvmGlobalPkg.vhd RandomPkg.vhd TextUtilPkg.vhd
CoveragePkg.vhd MessagePkg.vhd OsvvmContext.vhd RandomBasePkg.vhd SortListPkg_int.vhd TranscriptPkg.vhd

And the word “coreboard” appears just once in it :
AlertLogPkg.vhd: NewAlertLogRec(OSVVM_SCOREBOARD_ALERTLOG_ID, “OSVVM Scoreboard”, ALERTLOG_BASE_ID) ;

The relating function just decides about what AlertLog_ID belongs to the Scoreboard, That’s all.
So, what “scoreboard package” are you refering to? There can’t be documentation for a non-existing package.

You also say that you have printed training material. From what source? Is there such a package mentioned or provided that is yet unreleased for OSVVM? Don’t you have a cheap scanner somewhere around that can convert it into a PDF? Any multifunctional Priner/Scanner should be able to do this automatically (There are tools to merge front and back pages if you have no double side scanning device).

The Scoreboard does NOT check the responses from the DUT and compares to a reference value.
(That’s why it’s called Scoreboard and not OutputCompare)
It just keeps track of the results coming from some checks.
These might be acheived by comparing output values to some reference value (or reference model output).
But also PSL-Assertions or similar VHDL Checker functions might contribute to the Scoreboard.

The actions that are needed are also done using the coverage functions.

Say you have a module with an output value and a number of working modes.
Then you can create a covergroup that combines the modes with the output values (Crosscoverage).
(If there are impossible or unexpected output values, you can use IgnoreBin or IllegalBin to deal with it.)

Then you may have some loop like this:

if OutputCheck.IsCovered loop
CreateStimuli();
wait until OutputValid = ‘1’;
If CompareOutput() then
OutputCheck.ICover(Mode,OutputValue);
— maybe do some loggging
else
–Error Actions here
— e.G. Write to OSVVM_SCOREBOARD_ALERTLOG_ID
— But this makes only sense if the errors are non critical and the testbench continues
end loop

Once all output values in all modes appeared correctly you are done.
How fast that happens depends on your input stimuli.

Remember what you said :”… the coverage package, which only keeps track of what is tested, …”
Right, and that is not limited to stimuli, but also holds for verified results.

Just imagine: Due to some mistake your Testbench fails to change the modes.
From viewing your stimuli everything might look good and well covered.
But your OutputCheck Coverage will never complete and with a simple look at the Coverage report you will see the missing mode change appearing in the OutputCheck Covergroup.

I hope this was helpful.

Have a nice simulation
Eilert

[Martin Roenne]

Hi Eilert, thanks for your thoough answer. I participated in a OSVVM verification corse in 2014, where the Scoreboard package was part of the course and printed training material.

I I saw there was a “Coverage User guide” available, which I found excellent and even more thorough than the training material. I was looking for similar documentation for the scoreboard package.

The Scoreboard package was part of OSVVM at the time of my training course, but I agree, that it seems to have been removed from the latest releases. As you say, the coverage package can be used for verifying the response as well. Maybe this is the intention????

@Jim Lewis: Could you comment on the status of the Scoreboard package?

// Martin Roenne

[Jim Lewis]

Hi Martin,

Currently the Scoreboard package is only distributed with the class.  It has never formally been released as part of OSVVM although in the class it is in the same directory as the other OSVVM files.  It is a release candidate for OSVVM. 

One of my concerns has been vendor support.  I do not want to release packages into OSVVM when they are causing some tools to crash.  I will support my former students under these situations, however, I cannot support everyone. 

You should have received a quick reference card in the student handouts directory.  Also if you want the latest package, just send me an email.  The new Scoreboard package is well integrated with the newer AlertLogPkg (which became part of OSVVM in 2015). 

Best Regards,

Jim

[Martin Roenne]

Great to see that the ScoreboardPkg is now an official part of OSVVM 🙂

[Author]

Posts