[sv-cc] [Fwd: BOUNCE sv-cc@eda.org: Non-member submission from [Dave Scott - MTI south <dscott@model.com>]]

-------- Original Message --------
Subject: BOUNCE sv-cc@eda.org:    Non-member submission from [Dave Scott - MTI south <dscott@model.com>]
Date: Tue, 12 Jul 2005 11:34:01 -0700 (PDT)
From: owner-sv-cc@eda.org
To: sv-cc-approval@eda.org

 >From owner-sv-cc Tue Jul 12 11:34:00 2005
Received: from relay1.mentorg.com (relay1.mentorg.com [192.94.38.131])
	by server.eda.org (8.12.10/8.12.0.Beta7) with ESMTP id j6CIXxI1000279
	for <sv-cc@eda.org>; Tue, 12 Jul 2005 11:34:00 -0700 (PDT)
Received: from svr-orw-exc-10.mgc.mentorg.com ([147.34.98.58])
	by relay1.mentorg.com with esmtp
	id 1DsPZv-00067q-00 from david_scott@mentor.com
	for sv-cc@eda.org; Tue, 12 Jul 2005 11:33:59 -0700
Received: from SVR-CAS-EXC-02.mgc.mentorg.com ([134.86.188.54]) by SVR-ORW-EXC-10.mgc.mentorg.com with Microsoft SMTPSVC(6.0.3790.211);
	 Tue, 12 Jul 2005 11:33:59 -0700
Received: from [134.86.171.26] ([134.86.171.26]) by SVR-CAS-EXC-02.mgc.mentorg.com with Microsoft SMTPSVC(6.0.3790.211);
	 Tue, 12 Jul 2005 11:33:58 -0700
Message-ID: <42D40D0D.4050808@model.com>
Date: Tue, 12 Jul 2005 11:33:49 -0700
From: Dave Scott - MTI south <dscott@model.com>
User-Agent: Mozilla Thunderbird 1.0 (X11/20041206)
X-Accept-Language: en-us, en
MIME-Version: 1.0
To: "Rich, Dave" <Dave_Rich@mentor.com>
CC: systemverilog@listserv.mentorg.com, "Tam, Edmond" <Edmond_Tam@mentor.com>,
         sv-cc@server.eda.org
Subject: Re: [sv-ec] RE: [sv-cc] Coverpoint bins & functional coverage
References: <1457C0C86097894195741C8753959CAD03A4DDAE@svr-cas-exc-02.mgc.mentorg.com>
In-Reply-To: <1457C0C86097894195741C8753959CAD03A4DDAE@svr-cas-exc-02.mgc.mentorg.com>
Content-Type: text/plain; charset=ISO-8859-1; format=flowed
Content-Transfer-Encoding: 7bit
X-OriginalArrivalTime: 12 Jul 2005 18:33:58.0907 (UTC) FILETIME=[448A54B0:01C58710]
X-Virus-Scanned: ClamAV 0.83/976/Mon Jul 11 03:09:22 2005 on server.eda.org
X-Virus-Status: Clean

Dave --

Yes, there is a way to reference individual coverpoints (and crosses.)
There is NOT a way to reference individual bins and bin counts.

Look at Section 18.7.  Table 18-5 shows that get_coverage() and
get_inst_coverage(), for example, can be called in coverpoint or cross
scope.

Examples in 18.6 show how coverpoint scopes are to be referenced with
assignment of options, so this extends to the use of get_coverage() and
get_inst_coverage() calls.  There is some language in 18.7 that
indicates get_coverage() is called like a static class method.

So this leads to the following legal uses, that work in Questa 6.1 (note
because the covergroup has not been sampled in this example, all
coverage numbers are 0):

module top;
     int i;
     covergroup ct;
        cp: coverpoint i;
     endgroup

     ct cv = new;

     initial begin
        $display( ct::get_coverage() );
        $display( ct::cp::get_coverage() );
        $display( cv.get_coverage() );
        $display( cv.cp.get_coverage() );
        $display( cv.get_inst_coverage() );
        $display( cv.cp.get_inst_coverage() );
     end
endmodule

-- DaveS


Rich, Dave wrote:

 >Cliff,
 >
 >As far as I can tell, there is no mechanism, language or API, to access
 >individual bin counts, or even individual coverpoints. There is only the
 >get_coverage method that can be used on an instance of a covergroup, or
 >across all instances using the :: operator. That method only gives you
 >the total number of bins that have reached the at_least threshold.
 >
 >Currently, the only way to code for what you would like is to create a
 >separate covergroup for the specific purpose you want the testbench to
 >react to.
 >
 >It would be straightforward to extend get_coverage() to work on
 >individual, explicitly named coverpoints, since their naming conventions
 >are consistent with members of structs or classes. But naming of bins
 >gets complicated, especially when defining cross coverage.
 >
 >Dave
 >
 >



-- 
Charles Dawson
Senior Engineering Manager
NC-Verilog Team
Cadence Design Systems, Inc.
270 Billerica Road
Chelmsford, MA  01824
(978) 262 - 6273
chas@cadence.com