RE: [sv-ac] RE: Two items for ease of assertion writing

> 2. Is there a way to index an array enclosed by $past() using the
> current sampled value of a variable?
>
> for example
> txn_valid(txn_id) && $past(txn_valid[txn_id])
> ^want to index with the
> current sampled value
> of txn_id
>
> The only way I have figured out to make this work is to explicitly
> create a delayed version of txn_valid and use that instead of the
> $past() function.
>
> Another option I thought of just now would be to extend the $stable()
> system function to take an optional parameter for number of cycles.
>
>
> [Korchemny, Dmitry] If I understand your question correctly, you can
> write it as:
> txn_valid(txn_id) && $past(txn_valid[$sampled(txn_id)])
>
> I can enter Mantis items if either of these turns out to be more than
> just a user education issue.
>

[DR] This raises some serious issues regarding the nesting of sampled
value functions. Can they be nested? If so, does the sampling nest as
well. i.e.

$past(A && $past(B))

Are A and B both 1 cycle in the past or is B 2 cycles in the past?

Dave

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