RE: [sv-ac] FW: #805

From: Lisa Piper <piper_at_.....>
Date: Fri Jun 16 2006 - 08:29:19 PDT
Bassam and Manisha,

 

On page 469, it states "cbAssertionDisable. The assertion is disabled
(e.g. as a result of a control action)".

 

What is meant by "control action" - is this the "disable iff" clause of
an assertion or is this a system control task like assertkill or
vpi_control?   Is there and/or should there be a connection between an
assertion being disabled via "disable iff" versus the
assertoff/assertkill constructs and vpi_control(vpiAssertionDisable,
assertion_handle) (28.4.1).  

 

It seems clear to me that the 805 proposal currently focuses only on the
"disable iff" clause.  In section 29.4.3 and Annex I, can we change
vpiAssertDisableCovered to vpiAssertDisableIffCovered.  The use of
"disable" is too vague. The same applies to other such references of
"Disable".  This might solve my problem with getting confused with other
uses of disabled.

 

Lisa

 

 

 

________________________________

From: Eduard Cerny [mailto:Eduard.Cerny@synopsys.com] 
Sent: Wednesday, June 14, 2006 2:26 PM
To: Bassam Tabbara; Lisa Piper; Bassam Tabbara; Kulshrestha, Manisha;
Eduard Cerny; sv-ac@verilog.org
Subject: RE: [sv-ac] FW: #805

 

So the callback on disable is asynchronous, when it stops the attempt
(from starting or in flight).

ed

	 

	
________________________________


	From: Bassam Tabbara 
	Sent: Wednesday, June 14, 2006 2:22 PM
	To: Eduard Cerny; Lisa Piper; Bassam Tabbara; Kulshrestha,
Manisha; Eduard Cerny; sv-ac@verilog.org
	Subject: RE: [sv-ac] FW: #805

	The VPI uses the typical CB for some "event" that happened on a
registered assertion with a returned reason, the set of these
assertion-related reasons includes start/success/fail/disabled ....
Lisa, please review p. 469-470 of LRM for clarification on how this
works -- I didn't really get the premise/question/terminology in your
original email. so can't comment directly only recap. 

	 

	Of course yes this is very similar to the cbValueChange in VPI.
Yes this works per attempt, no it does not miss anything -- Actually you
get a cb for start of attempt then a callback for
"result":success/fail/disabled/....  As I stated earlier, if you want to
disable all assertions you would use the "system" variants corresponding
to assertion/off/.... that is not per assertion (attempt).

	 

	Thx.

	-Bassam.

	 

	 

	
________________________________


	From: Eduard Cerny 
	Sent: Wednesday, June 14, 2006 6:19 AM
	To: Lisa Piper; Bassam Tabbara; Kulshrestha, Manisha; Eduard
Cerny; sv-ac@verilog.org
	Subject: RE: [sv-ac] FW: #805

	Isn't it that the disbale iff, although asynchronous is
interpreted in the synchronous context of the assertions as

	- not starting a new attempt, and

	- killing attempts in flight.

	 

	The first one could be tied to the clock of the disabled
assertion. The 2nd one seems more problematic. In that case, the value
change of the condition could trigger the call back as Lisa suggests.
So, either a clock tick and disable condition being true or a change of
disable if condition to true (for all attempts in flight). Does that
make sense?

	 

	ed

		 

		
________________________________


		From: Lisa Piper [mailto:piper@cadence.com] 
		Sent: Monday, June 12, 2006 9:26 AM
		To: Bassam Tabbara; Kulshrestha, Manisha; Eduard Cerny;
sv-ac@verilog.org
		Subject: RE: [sv-ac] FW: #805

		I have a question - "disable iff" is asynchronous.
Below it is stated that there is always a callback per attempt.  If it
is per attempt, you could miss it.  So will "disable iff" callbacks
happen every simulation cycle, or every attempt?  I don't like the idea
of having one every simulation cycle.  Perhaps it could be defined as a
callback when it changes value.

		 

		lisa

		 

		
________________________________


		From: owner-sv-ac@verilog.org
[mailto:owner-sv-ac@verilog.org] On Behalf Of Bassam Tabbara
		Sent: Friday, June 09, 2006 2:57 PM
		To: Kulshrestha, Manisha; Eduard Cerny;
sv-ac@verilog.org
		Subject: RE: [sv-ac] FW: #805

		 

		Hi Manisha,

		 

		I think this is ok as is. About your concern, we are
always issuing a callback per attempt result so this is no different.
There is another set of callbacks (cbAssertionSys...) for a wide scale
(all assertions) on/off/disable (aka kill), obviously that's only one CB
until the next start/enable, under user control here not a matter of
sampling a signal as in former.

		 

		** Ed, like the other ticket (I forget #), we should add
SV-CC for reviewing VPI part as well once we are done with ticket in AC.

		 

		Thx.

		-Bassam.

		 

		 

		
________________________________


		From: owner-sv-ac@verilog.org
[mailto:owner-sv-ac@verilog.org] On Behalf Of Kulshrestha, Manisha
		Sent: Friday, June 09, 2006 11:35 AM
		To: Eduard Cerny; sv-ac@verilog.org
		Subject: RE: [sv-ac] FW: #805

		Hi All,

		 

		I have uploaded a new version of the proposal on mantis.
This includes suggestions by Lisa (done differently than suggested) and
corrections from Ed ( I have made succeeded to succeeded nonvacuously). 

		Ed, I have made the corrections but I am not sure about
usefulness of those callbacks. I feel callback on each disable
evaluation when disable is already true, is going to be unnecessary and
expensive. Probably Bassam can suggest something. Anyone else ?

		 

		Thanks.

		Manisha

		 

		
________________________________


		From: Eduard Cerny [mailto:Eduard.Cerny@synopsys.com] 
		Sent: Thursday, June 08, 2006 7:39 AM
		To: Kulshrestha, Manisha; sv-ac@verilog.org
		Subject: RE: [sv-ac] FW: #805

		Manisha, 

		 

		the last statement in the document you sent says:

		 

		- cbAssertionSuccess, cbAssertionVacuousSuccess,
cbAssertionDisabledEvaluation and cbAssertionFailure: cb_time is the
time when the assertion succeeded or failed.

		 

		Should it say that in the case of disabled evaluation it
is the time when it was disabled? Rather than just succeeded or failed?
Is it useful to report disabled time likely to be the start time in many
cases?) Also, under succeeded, does it cover vacuous success? 

		 

		Best regards,

		ed

			 

			
________________________________


			From: owner-sv-ac@verilog.org
[mailto:owner-sv-ac@verilog.org] On Behalf Of Kulshrestha, Manisha
			Sent: Tuesday, June 06, 2006 11:50 AM
			To: sv-ac@verilog.org
			Subject: [sv-ac] FW: #805

			
			
			
			

			-----Original Message-----
			From: Kulshrestha, Manisha
			Sent: Thu 6/1/2006 12:17 PM
			To: 'sv-ac@eda.org'
			Subject: #805
			
			
			Hi All,
			
			I have incorporated most of the feedback in my
updated proposal (attached here). Please send your feedback. The
original proposals are still on mantis in case you want to compare. The
main change in this document is that disabled is not a success and thus
very few changes are needed in the LRM.
			
			Thanks.
			Manisha
			
			805: disable iff condition should produce
vacuous match
			Lisa:           I agree with this too - failure
counters do not make
			                        sense for coverage.
			                        failure counters do not
make sense for coverage.
			Joseph:         yes
			Doron:          I think that disabled should not
count as a success 
			                        in coverage. we need to
change is the report of the 
			                        number of failures in
coverage
			Bassam:         yes
			Dmitry:         I don't think the failure should
be reported for coverage at all.
			Surrendra:      yes
			Ed:                     No success with disable
to be reported.
			Dmitry:         I agree with the definition of
the vacuous success.
			                        According to our
discussion about the property
			                        coverage definition,
there is no meaning in disabled
			                        coverage success, since
it should not count as a
			                        coverage event at all. 
			                        Therefore the
suggestions concerning
			                        Clause 17.13.3, page
288,
			                        Clause 29.4.3, page 482,
Clause 29.4.2, page 481,
			                        and Annex I are not
relevant.
			                        I agree with the
proposal concerning  Clause 28.4.2.
			Volkan:         yes
Received on Fri Jun 16 08:29:38 2006

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