From: Charles Dawson (chas@cadence.com)
Date: Tue Jul 02 2002 - 14:08:38 PDT
Precedence: bulk
I think it would be very reasonable and appropriate to refer this item to
the PTF so they can make a proposal on how to resolve the issue.
-Chas
Steven Sharp wrote:
>
> >Actually, this doesn't seem sufficient when the base expression
> >is actually constant, i.e.
> >
> > reg [31:0] vector;
> >
> > vector[31-:8] // both base and width are constant, thus vpiConstantSelect
> == true,
> > // but this is not a regular part-select
>
> I think it is time to let Charles answer this, instead of me trying
> to recall what he said. Either vpiConstantSelect was supposed to be
> false in this case (making it a poor choice of names for the property),
> or VPI was supposed to convert the constant case into an equivalent
> non-indexed part select and return the range values for that, or
> something else that I didn't understand at the time.
>
> >Given the counterexample above, it would seem a new property (properties??)
> >of part selects is needed at the very least to determine whether a part select
> >is an index part select, and which type of indexed part-select.
> >
> >Or, alternatively, entirely new VPI objects to represent +: and -: could be
> >defined.
>
> This may have been another situation where the extension was changed after
> the PLI task force had dealt with it, and they didn't compensate for the
> change. The original proposal didn't have two variations (though it had
> other more serious problems).
>
> Steven Sharp
> sharp@cadence.com
-- Charles Dawson Senior Engineering Manager NC-Verilog Team Cadence Design Systems, Inc. 270 Billerica Road Chelmsford, MA 01824 (978) 262 - 6273 chas@cadence.com
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