FW: Analysis of IR2062

Ajay,

I agree with the general sense of your proposed change, but I think you've
inadvertently omitted a case that needs to be there.  You write:

In section 7.4.2, change the sentence 

    "A globally static range is either a range of the second form 
     (see  3.1  ) whose bounds are globally static expressions, or a 
     range of the first form whose prefix denotes either a globally 
     static subtype or an object that is of a globally static subtype."

to the following.

    "A globally static range is either a range of the second form 
     (see  3.1 ) whose bounds are globally static expressions, or a 
     range of the first form whose prefix either denotes a globally 
     static subtype or is a globally static primary that denotes an object."

However, the words "an object that is of a globally static subtype" cover,
for example, a signal that is declared to be of a constrained subtype, such
as

  generic ( width : natural )
  ...
  signal s : bit_vector(0 to width - 1);

The words make the attribute name s'range globally static, since s is of a
globally static subtype.  However, s is not a globally static primary.

I'd suggest the changed wording be

     ... or a range of the first form whose prefix denotes either a globally

     static subtype or an object that is of a globally static subtype or
whose
     prefix is a globally static primary.

Note that the same issue arises in items j) and k) of the list of globally
static primaries.  For example, currently, in

  generic ( a : bit_vector )
  ...
  ... a'length ... a'

a'length is not currently globally static.  This would be fixed by allowing
the prefix of the attribute name in j) and k) to be a globally static
primary.

Note also that analogous problems arises in description of locally static
ranges and attribute names.  However, there is an FT proposal to require a
constant (or an alias) to have a locally static subtype in order to be
locally static.  With that change, we don't need to revise the definition of
locally static ranges or attribute names.

Cheers,

PA

--
Dr. Peter J. Ashenden                        peter@ashenden.com.au
Ashenden Designs Pty. Ltd.                   www.ashenden.com.au
PO Box 640                                   Ph:  +61 8 8339 7532
Stirling, SA 5152                            Fax: +61 8 8339 2616
Australia                                    Mobile: +61 414 70 9106


> -----Original Message-----
> From: owner-isac@eda.org [mailto:owner-isac@eda.org] On
> Behalf Of Ajayharsh Varikat
> Sent: Wednesday, 6 April 2005 23:43
> To: cswart@model.com
> Cc: isac@eda.org
> Subject: Analysis of IR2062
> 
> 
> 
> Please find attached my analysis of IR2062.
> 
> -ajay
>