Re: [sv-ac] RE: call to vote on 1900

Hi Manisha, Dmitry:

I agree with Manisha's concern about blurring the distinction 
between "matched" and "ended".

Since the SV 3.1 LRM, we have said that "matched" cannot 
synchronize simultaneously between the ending clock of the 
sequence to which it is applied and the clock governing the
context in which .matched appears.  Back in those days, there
was concern about any construct involving multiple clocks 
that was not sythesizable, and catching simultaneity of the 
two clocks was excluded.

This made the SV 3.1 (and subsequent) "matched" different than
the OVA/ForSpec 2.0 "matched" that was donated to Accellera.
The OVA/ForSpec 2.0 "matched" allowed the synchronization disallowed
for SV 3.1 "matched".

This decision is an old one, and it has the consequence that,
for r with no clock, the limit as d approaches c of

   @(d) (@(c) r).matched

is

   @(c) (r ##1 1).ended

rather than 

   @(c) r.ended


J.H.


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> Thread-Topic: [sv-ac] RE: call to vote on 1900
> Thread-Index: AchLzns79+5/Vq/hRSihRqc9b3l1nwFRom7wACyzDsAARdh1kAAtZ1OgACJrbKA=
> From: "Kulshrestha, Manisha" <Manisha_Kulshrestha@mentor.com>
> Cc: "Bustan, Doron" <doron.bustan@intel.com>, <eduard.cerny@synopsys.com>,
>         <yaniv.fais@freescale.com>, <johan.martensson@jasper-da.com>,
>         <piper@cadence.com>, "Seligman, Erik" <erik.seligman@intel.com>,
>         <bassam.tabbara@synopsys.com>, <thomas.thatcher@sun.com>
> X-OriginalArrivalTime: 11 Jan 2008 06:57:40.0128 (UTC) FILETIME=[41985200:01C8541F]
> 
> Hi Dimitry,
> 
> I am still not convinced that matched should be allowed in continuous
> assignments. I know that you are explicitly stating that it will work
> like ended and triggered, but still I do not feel any need to allow it
> there (I feel it might just confuse the users as there is no
> multiclock). Also, the definition of matched in the formal semantics
> does not match with this statement.=20
> 
> Thanks.
> Manisha
> 

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