RE: IEEE Std 1364-2001, 19.2 and Annex B -- 'none' keyword

From: Brad Pierce (Brad.Pierce@synopsys.com)
Date: Wed Oct 02 2002 - 09:09:07 PDT

Ok, that works for me. Likewise, the other net_types in this directive,
such as 'wire', 'tri', etc. are not reserved keywords either. They are just
syntax that happens to mirror the corresponding reserved keywords.

A related issue though is that the net_type production in Syntax 19-1 is
inconsistent with the net_type production in A.2.2.1. I guess these are
meant to be nonterminals from two independent grammars and those
nonterminals just happen to have the same name. However, if the grammars
are really independent, then how can we use simple_identifier in Syntax 19-2
without defining it in section 19?

-- Brad
  -----Original Message-----
  From: owner-etf@boyd.com [mailto:owner-etf@boyd.com]On Behalf Of Shalom
Bresticker
  Sent: Tuesday, October 01, 2002 11:05 PM
  To: Steven Sharp
  Cc: etf@boyd.com; Brad.Pierce@synopsys.COM
  Subject: Re: IEEE Std 1364-2001, 19.2 and Annex B -- 'none' keyword

  It's not a hack at all.
  `default_nettype is a compiler directive.
  All the rules about reserved keywords don't apply to compiler directives.

  Shalom

  Steven Sharp wrote:

>Section 19.2 (`default_nettype) uses the keyword 'none', but 'none' is
not
>listed in the list of keywords in Annex B.
    We implemented it in NC-Verilog as written, without reserving "none" as
a
    keyword. We allowed any of the net type keywords or the identifier
"none".
    That was how I interpreted the standard. It is a bit of a hack, but
    directives accept some strange syntax already. For example in
    `timescale 1ns/1ns
    "ns" isn't a reserved word. It is just a set of characters that are
legal
    in that position in the directive, like "none" in `default_nettype.

    So I wouldn't consider this an erratum. Others might disagree. 

--
Shalom Bresticker                           Shalom.Bresticker@motorola.com
Design & Reuse Methodology                             Tel: +972 9 9522268
Motorola Semiconductor Israel, Ltd.                    Fax: +972 9 9522890
POB 2208, Herzlia 46120, ISRAEL                       Cell: +972 50 441478

"The devil is in the details."

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