Re: [sv-ac] Re: [sv-ec] Re: [sv-bc] question about integer expression

From: Gordon Vreugdenhil <gordonv_at_.....>
Date: Fri Apr 03 2009 - 14:42:03 PDT
Arturo Salz wrote:
> Gord,
> 
> I believe the discussion is not restricted to testbench, and 
 > I showed earlier an example of an array declaration that
 > satisfies the 2^16 limit, but has nonetheless index bounds
 > that are larger than 32-bits:
> 
>         reg [48'hfffffffffff0:48'hfffffffffff3] foo;
> 
> The above is a 4-bit (wide) vector, but the index bounds 
 > are 48-bit wide. I agree with all of you that there are real
> practical concerns as well as legacy issues, and I believe that 
> most implementations will have issues with the above declaration, 
> and I am unsure whether it is even legal or not.


Yup, that is exactly why I said:
 > Splitting hairs, the above doesn't say that the index *range*
 > must be bounded by 24 bit values, but preceding text is
 > certainly consistent with that assumption.

If one wants to split hairs about the 24 bit size aspect to
say that only the *count* and not the *range* is restricted,
then I'm perfectly happy to split the hairs in the preceding text
to claim that "integer" is in fact normative to 32 bits for
index values.

Also as I said, if one wants to intentionally relax the 32 bit
assumptions, there is a much deeper scrub necessary and I'm not
entirely sure that I'd be willing to support such a change.

Gord.

-- 
--------------------------------------------------------------------
Gordon Vreugdenhil                                503-685-0808
Model Technology (Mentor Graphics)                gordonv@model.com


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Received on Fri Apr 3 14:43:41 2009

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