ISSUE 182

Number 182
Category errata
Synopsis Syntax 9-8: event_control
State lrmdraft
Class errata-simple
Arrival-DateOct 31 2002
Originator Shalom.Bresticker@motorola.com
Release 2001b, 9.7 (Syntax 9-8), 9.7.7 (Syntax 9-12), A.6.5, Syntaxes 9-1, 9-2
Environment
Description

Syntax 9-8 says event_control may be

@ event_identifier or
@ ( event_expression )
...
etc.

where event_identifier ::= identifier

and event_expression includes hierarchichal_identifier.


This seems to imply that @a.b should be illegal
and you would have to write @(a.b).

Yet I see that Verilog-XL accepts the @a.b form.

Should event_control be changed to

@ hierarchical_event_identifier
| @ ( event_expression )
...

?




Fix
In A.6.5 and Syntaxes 9-1, 9-2, 9-8, 9-12 change

event_control ::= @ event_identifier
| @ ( event_expression )
| @ *
| @ ( * )

event_expression ::= expression
| hierarchical_identifier
| posedge expression
| negedge expression
| event_expression or event_expression
| event_expression , event_expression

to

event_control ::= @ hierarchical_event_identifier
| @ ( event_expression )
| @ *
| @ ( * )

event_expression ::= expression
| posedge expression
| negedge expression
| event_expression or event_expression
| event_expression , event_expression

Audit-Trail

From: "Brad Pierce" <Brad.Pierce@synopsys.com>
To: <etf-bugs@boyd.com>
Cc:
Subject: Re: errata/182: Syntax 9-8: event_control
Date: Fri, 22 Nov 2002 09:24:19 -0800

>Category: errata
>Confidential: no
>Originator: "Brad Pierce" <Brad.Pierce@synopsys.com>
>Release: 2001b
>Class: TBD
>Description:
Also, as Dan Jacobi pointed out, the
"hierarchical_identifier" production should
be removed from "event_expression", because
it adds ambiguity. A hierarchical_identifier
is an expression.

event_expression ::=
expression
| hierarchical_identifier <---- remove
| ...

-- Brad



From: "Brad Pierce" <Brad.Pierce@synopsys.com>
To: <etf-bugs@boyd.com>
Cc:
Subject: Re: errata/182: PROPOSAL
Date: Mon, 2 Dec 2002 11:32:53 -0800

In A.6.5 and Syntax 9-8 change

event_control ::=
@ event_identifier
| @ (event_expression)
| @ *
| @ ( * )

event_expression ::=
expression
| hierarchical_identifier
| posedge expression
| negedge expression
| event_expression or event_expression
| event_expression , event_expression

to

event_control ::=
@ hierarchical_event_identifier
| @ (event_expression)
| @ *
| @ ( * )

event_expression ::=
expression
| posedge expression
| negedge expression
| event_expression or event_expression
| event_expression , event_expression


From: Shalom.Bresticker@motorola.com
To: Steven Sharp <sharp@cadence.com>
Cc: etf-bugs@boyd.com
Subject: Re: errata/182
Date: Sat, 18 Jan 2003 20:56:58 +0200 (IST)

>Category: errata
>Confidential: no
>Originator: Shalom.Bresticker@motorola.com
>Release: 2001b
>Class: TBD
>Description:
I don't see any necessary connection between them.
However, if you really want to bundle them together,
then it is clear to me that it is delay_value that has to change to allow a
hierarchical_identifier.

> >However we handle #182, either both #a.b and @a.b should be allowed,
> >or neither should be allowed.
>
> NC-Verilog and Verilog-XL allow both. At any rate, it sounds like more
> discussion is called for, to change either #182 or #174.


From: Shalom.Bresticker@motorola.com
To: etf-bugs@boyd.com
Cc:
Subject: Re: errata/182 - Syntax 9-8: event_control
Date: Sun, 26 Jan 2003 09:55:51 +0200 (IST)

>Category: errata
>Confidential: no
>Originator: Shalom.Bresticker@motorola.com
>Release: 2001b
>Class: TBD
>Description:
Another point for thought:

In the proposal,

event_control ::= @ hierarchical_event_identifier
| @ ( event_expression )
| @ *
| @ ( * )

Presumably "hierarchical_event_identifier" would have to change to

hierarchical_event_identifier { "[" expression "]" } .

Shalom



> I don't see any necessary connection between them.
> However, if you really want to bundle them together,
> then it is clear to me that it is delay_value that has to change to allow a
> hierarchical_identifier.
>
> > >However we handle #182, either both #a.b and @a.b should be allowed,
> > >or neither should be allowed.
> >
> > NC-Verilog and Verilog-XL allow both. At any rate, it sounds like more
> > discussion is called for, to change either #182 or #174.
>


Unformatted


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