Re: Hierarchical references

David Sharrit wrote:
>> When accessing variable values and probes on named branches the value as
>> per the last iteration shall be returned (to avoid race conditions) and
>> without affecting any partial dependencies. 
>>     

I thought the "race condition" argument had been debunked, i.e. analog 
processes are solved with a copy-in/copy-out semantic that means the 
only possible race condition is during the copy-out.

I'm also losing track of how many times we've been round through this: 
there shouldn't be any semantic difference between branches/variables 
accessed locally or through OOMRs - if there is it will just cause 
unnecessary errors.

Kev.

>
> Perhaps I'm just confused, but even after I consider this to just be talking
> about variable values, I'm still uncertain and concerned as to what this is
> really trying to do or provide.  What exactly is the "value as per the last
> iteration"?  Presumably that is, or could be, the previous time point value
> in a transient simulation.  For a time varying variable, will that not
> result in fairly unpredictable and inconsistent results, as it will depend
> on the particular timestep involved? And what does it even mean for other
> analysis types, such as AC or HB or even DC?  Without derivative
> information, it seems you could either be introducing convergence failures
> with incorrect Jacobians, or inconsistent (incorrect) results, with state
> variable dependencies seeming to exist in transient simulations but not in
> AC simulations.
>
> It seems there were some major reasons why OOMR access to variable values is
> disallowed in the present LRM, and I don't yet see how these issues have
> been cleanly, accurately or practically resolved.
>
> David
>
>
>
>   


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