RE: [sv-ec] Effect of ignore/illegal bins - Mantis #1237

Hi Arturo,
 
Yes, I agree. This makes sense.
Thanks for your explanation.
 
Swapnajit.


________________________________

	From: Arturo Salz [mailto:Arturo.Salz@synopsys.com] 
	Sent: Monday, February 13, 2006 1:38 PM
	To: Swapnajit Chakraborti; Ryan, Ray; sv-ec@eda.org
	Subject: RE: [sv-ec] Effect of ignore/illegal bins - Mantis
#1237
	
	

	Swapnajit,

	 

	That line means that the distribution of values into the bins,
i.e., the space computation, must happen first, disregarding any
ignored/illegal bins specified. Then, after the bins have been computed,
ignore values are computed, which may result in some bins having no
values (empty bins). This is covered by the proposed example for
18.10.1:

	 

	bit [2:0] a,b;
	covergroup ct;
	    coverpoint b {
	        option.auto_bin_max = 4;
	        ignore_bins ig = { [0:1], [5:6] };
	    }

	endgroup

	 

	In this case, coverpoint b will have 4 auto bins: auto[0,1],
auto[2,3], auto[4,5], auto[6,7]. The ignore_bins declaration specifies
that the values 0,1,5,6 are ignored. After applying the ignore_bins, the
bins are: auto[], auto[2,3], auto[4], auto[7]. Since it no longer is
associated with any value, 'auto[]' does not contribute to coverage.

	 

	Without that clarification, someone may consider implementing
ignored bins in the reverse order, that is, first remove the ignored
values and the distribute the remaining (non-ignored) values onto bins.

	 

	            Arturo

	 

	
________________________________


	From: Swapnajit Chakraborti [mailto:swapnaj@cadence.com] 
	Sent: Sunday, February 12, 2006 8:48 PM
	To: Arturo Salz; Ryan, Ray; sv-ec@eda.org
	Subject: RE: [sv-ec] Effect of ignore/illegal bins - Mantis
#1237

	 

	Arturo & Ray, 

	Could you please elaborate the following line added in this
mantis: 

	" The removal of ignored values shall occur after the
distribution of values to the specified bins." 

	Thx, 
	Swapnajit. 

	>-----Original Message----- 
	>From: owner-sv-ec@eda.org [mailto:owner-sv-ec@eda.org
<mailto:owner-sv-ec@eda.org> ] On 
	>Behalf Of Arturo Salz 
	>Sent: Sunday, February 12, 2006 1:04 AM 
	>To: Ryan, Ray; sv-ec@eda.org 
	>Subject: RE: [sv-ec] Effect of ignore/illegal bins - Mantis
#1237 
	> 
	>Ray, 
	> 
	>Attached is a modified proposal with some minor friendly
amendments. 
	>The amendments do not change the proposal's semantics, only 
	>the verbiage. 
	> 
	>       Arturo 
	> 
	>-----Original Message----- 
	>From: owner-sv-ec@eda.org [mailto:owner-sv-ec@eda.org
<mailto:owner-sv-ec@eda.org> ] On 
	>Behalf Of Ryan, Ray 
	>Sent: Friday, February 10, 2006 4:29 PM 
	>To: sv-ec@eda.org 
	>Subject: [sv-ec] Effect of ignore/illegal bins - Mantis #1237 
	> 
	>Attached is a proposal for mantix #1237. 
	> 
	>- values are distributed, then ignore/illegal bins applied. 
	>- bins with no values/transitions do not contribute to coverage

	>- coverpoint with no contributing bins does not contribute to
coverage 
	>- covergroup with no contributing items does not contribute to 
	>overall coverage 
	>- ignore/illegal VALUES do not effect transitions. 
	> 
	>- Ray 
	>