Support for retaining_fall / retaining_rise

[smunaut]

At the moment I'm a bit confused how to best describe behavior of a memory when for instance the data output becomes invalid after 1 ns but the new valid data output is only after 4 ns.

As far as I can tell the way to describe this is using retaining_fall / retaining_rise constraint, but AFAICT this is not supported at the moment.

Is there another way ? Or is this supported and I missed it ? Or is support planned ?

[jjcherry56]

It is not supported and there is no plan to support it at this point.

[smunaut]

Ok, fair enough.

So what's the recommended way to describe in the liberty file the situation I described above using supported features ?
This seems like a basic need to do proper timing analysis of a memory but I'm a novice at writing liberty files so I must be missing something somewhere.