AlertLogPkg: AffirmIf with std_match (as implemented in the ScoreBoardPkg) about osvvm

[JimLewis]

Hi Sebastian,
The intent is that both ScoreboardPkg_slv and AffirmIfEqual/AlertIfEqual/AlertIfNotEqual all use osvvm.AlertLogPkg.MetaMatch (which is similar to std_match - differences noted below).

For AffirmIf, it is up to you to use MetaMatch, std_match, or "=" in your expression, AffirmIf(MetaMatch(MyVal, ExpVal), ... or alternately use the simpler expression, AffirmIfEqual(MyVal, ExpVal, "Simplified Message prefix"); Note that AffirmIfEqual already prints the "Expected: ExpectedVal" and if there is an error, "/= Actual: ActualVal".

I just did a manual check of AffirmIfEqual and AlertIfEqual/AlertIfNotEqual in the current release. I found that they all use MetaMatch with the std_ulogic family. That said, it is possible I missed something, so it would be helpful to know which one is doing something unexpected.

If there is an issue, the work around is to use the longer AffirmIf(MetaMatch(A, B) , .... instead of AffirmIfEqual.

With respect to 2022.02, the release notes say that:

• ScoreboardPkg_slv switched to using MetaMatch in 2020.10.
• AlertLogPkg, AffirmIfEqual switched to using MetaMatch in 2020.12.

I don't see any notes about something being fixed later, but it could have been.

MetaMatch is like std_match except that MetaMatch also considers X = X as true where std_match considers this to be false.
MetaMatch is uses this table:

  constant MetaMatchTable : BooleanTableType := (
    --------------------------------------------------------------------------
    -- U      X      0      1      Z      W      L      H      -
    --------------------------------------------------------------------------
    (TRUE,  FALSE, FALSE, FALSE, FALSE, FALSE, FALSE, FALSE, TRUE),  -- | U |
    (FALSE, TRUE,  FALSE, FALSE, FALSE, FALSE, FALSE, FALSE, TRUE),  -- | X |
    (FALSE, FALSE, TRUE,  FALSE, FALSE, FALSE, TRUE,  FALSE, TRUE),  -- | 0 |
    (FALSE, FALSE, FALSE, TRUE,  FALSE, FALSE, FALSE, TRUE,  TRUE),  -- | 1 |
    (FALSE, FALSE, FALSE, FALSE, TRUE,  FALSE, FALSE, FALSE, TRUE),  -- | Z |
    (FALSE, FALSE, FALSE, FALSE, FALSE, TRUE,  FALSE, FALSE, TRUE),  -- | W |
    (FALSE, FALSE, TRUE,  FALSE, FALSE, FALSE, TRUE,  FALSE, TRUE),  -- | L |
    (FALSE, FALSE, FALSE, TRUE,  FALSE, FALSE, FALSE, TRUE,  TRUE),  -- | H |
    (TRUE,  TRUE,  TRUE,  TRUE,  TRUE,  TRUE,  TRUE,  TRUE,  TRUE)   -- | - |
    );

[SebDunst]

Hi Jim,

I didn't realize that I only have to use the MetaMatch function.

Thanks a lot!

Regards,
Sebastian

[JimLewis]

Or use AffirmIfEqual