RE: [sv-ac] AC 196:

Manisha,

SVA is part of SystemVerilog. It is much more important that SVA is consistent with SV over SVA being
consistent with PSL. As an SVA fan making it more consistent with SV is a differentiating factor to the
advantage of SVA.

Regards
Hillel

-----Original Message-----
From: owner-sv-ac@eda.org [mailto:owner-sv-ac@eda.org]On Behalf Of Kulshrestha, Manisha
Sent: Wednesday, November 17, 2004 10:32 PM
To: sv-ac@eda.org
Subject: RE: [sv-ac] AC 196:

Hi Hillel,

I like the idea of adding types to the properties. But this
issue of passing by value vs. reference seems to be a complete
new way of looking at properties. Also, passing by value makes
it inconsistent from psl.

Manisha

-----Original Message-----
From: owner-sv-ac@eda.org [mailto:owner-sv-ac@eda.org] On Behalf Of Adam
Krolnik
Sent: Wednesday, November 17, 2004 11:52 AM
To: Miller Hillel-R53776; sv-ac@eda.org
Subject: Re: [sv-ac] AC 196:

Hi Hillel;

You wrote:

>Justification of both capabilities is based on the fact that most
popular languages >support both >types of parameters. This includes
SystemVerilog.

What I was thinking for justification a set of properties/sequences is
provided that you wish to write and why the pass-by-value functionality
should be included.

You wrote:

>For pass by value, this:
> reg val1, val2;
> ... (val1 = parameter_a, val2 = parameter_b,
property_rule6(val1, val2)) ...
>becomes, this:
> ... property_rule6(parameter_a, parameter_b) ...
>which is already simpler. It also may execute faster.

However, IMHO, the most common cases of properties and sequences would
be:

     property my_simple_property_with_arguments(valid, datum) ...

This would have an error prone declaration if one chooses to formally
declare the types of the arguments (hoping to provide a safety and
documentation to the
user.)

    property my_simple_property_with_arguments(
        ref reg valid, // must be ref...
        ref reg datum // must be ref...
        );
   ...

Should the user forget to add the 'ref' keyword, they obtain a most
likely invalid property.

    property my_simple_property_with_arguments(
        reg valid, // Whoops! only one value now!
        reg datum // Whoops! only one value now!
        );
      ...

There has not been confusion on the model of sequences and properties
being module like or task call like before. I fear choosing a task call
like model provides a more dangerous syntax and little overall benefit.
This model we speak of does not even impact the implementation of
sequences and properties. Thus I would ask that consideration be given
to ease of use, when choosing a conceptual model to explain a
specification from.

     Thanks.

    Adam Krolnik
    Verification Mgr.
    LSI Logic Corp.
    Plano TX. 75074
    Co-author "Assertion-Based Design"
Received on Fri Nov 19 00:20:36 2004