Re: [sv-ac] [Fwd: Clock flow in SV assertion]

From: Surya Pratik Saha <spsaha_at_.....>
Date: Wed Mar 08 2006 - 19:56:56 PST

Hi Manisha,
How did you set precedence low for the first '@' operator and then high for rest. In normal parser generator for e.g. bison, you can not set precedence of a terminal as per context. That should be defined before. So either the precedence will be high or low.

If instead of |=> operaotr, 'or' is present, how then it will be parased?

@(posedge clk) ((a ##1 (@(posedge clk1) s1)) or (@(posedge clk2) s2));

or

@(posedge clk) ((a ##1 (@(posedge clk1) s1) or (@(posedge clk2) s2)));

Please can you explain.

"Kulshrestha, Manisha" wrote:

 

Surya,

The precedence rules apply when there is conflict. In this case there is no conflict (as you already stated that a property expression can not be after ##1), so the parser will resolve it as:

@(posedge clk) ((a ##1 (@(posedge clk1) s1)) |=> (@(posedge clk2) s2));

Manisha

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From: owner-sv-ac@eda.org [mailto:owner-sv-ac@eda.org] On Behalf Of Surya Pratik Saha
Sent: Wednesday, March 08, 2006 1:53 AM
To: sv-ac@eda.org
Subject: [sv-ac] [Fwd: Clock flow in SV assertion]

-------- Original Message --------

Subject:	Clock flow in SV assertion
Date:	Wed, 08 Mar 2006 10:28:44 +0530
From:	Surya Pratik Saha <spsaha@cal.interrasystems.com>
To:	"sv-bc@eda.org" <sv-bc@eda.org>, sv-ac@eda.org

Hi,
Some days ago I asked the precedence of @ operator in assertion rule. I did not get well defined answer, however by reading the clock flow section, it is understood that @ has the weakest precedence.

Considering the fact the given e.g. in LRM (page no. 282, e.g. d)

@(posedge clk) a ##1 @(posedge clk1) s1 |=> @(posedge clk2) s2;

will be parsed as:

@(posedge clk) a ##1 (@(posedge clk1) s1 |=> @(posedge clk2) s2);

So (@(posedge clk1) s1 |=> @(posedge clk2) s2) will become a property expression.

But as per assertion BNF, ## operator can not have property expression in RHS. So the e.g. given in LRM is wrong.

Please confirm.

-- 
Regards
Surya.

 

-- 
Regards
Surya.

  Received on Wed Mar 8 19:55:53 2006