Re: errata/467: assignments on port declarations 12.3

From: Shalom.Bresticker@motorola.com
Date: Mon Sep 15 2003 - 07:00:07 PDT

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    The following reply was made to PR errata/467; it has been noted by GNATS.

    From: Shalom.Bresticker@motorola.com
    To: sharp@cadence.com
    Cc: etf-bugs@boyd.com
    Subject: Re: errata/467: assignments on port declarations 12.3
    Date: Sun, 14 Sep 2003 14:06:23 +0300 (IDT)

     The general form of a net declaration assignment also allows
     you to add delay and drive strength specifications.
     These are also not allowed in port declarations.
     
     Shalom
     
     
    > Looking at the BNF, it appears to allow reg declaration
    > initializers on reg port declarations, both the combined
    > reg port declarations inside the module and the ANSI-C
    > style reg port declarations in the port list.
    >
    > It does not allow continuous assignments on net declarations
    > if those are net port declarations, whether those are
    > combined net port declarations inside the module or ANSI-C
    > style net port declarations in the port list.
    >
    > So the BNF allows both
    >
    > module m (output reg r = 0);
    >
    > and
    >
    > module m (r);
    > output reg r = 0;
    >
    > But it does not allow either
    >
    > module m (output wire w = 0);
    >
    > or
    >
    > module m (w);
    > output wire w = 0;
    >
    > even though it allows
    >
    > module m (w);
    > output w;
    > wire w = 0;
    >
    > Is this what was intended? I can see some logic to this,
    > since you can't really assign much besides constants this
    > way (at least in the ANSI-C style port declarations).
    > That makes sense for a reg initializer, but is of limited
    > use for a continuous assignment.
     

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