RE: [sv-ac] Statistics counters proposal

Thanks Ed!   
 
I agree with your point on the disable iff.  It should be looking at the
"property_spec" only.   I think the existing text misled me on this.
 
I'm not sure I like restricting it to a sequence instance because then
it will always be a two step process to define it (e.g. I would have to
define the sequence and then use the cover property).  
In case it was not clear, this is important since the coverage results
are stated to be different depending on whether the property_spec is a
sequence (all match) or a property (1 match per attempt)..
 
Lisa


________________________________

	From: Eduard Cerny [mailto:Eduard.Cerny@synopsys.com] 
	Sent: Monday, May 07, 2007 2:09 PM
	To: Lisa Piper; sv-ac@eda.org
	Subject: RE: [sv-ac] Statistics counters proposal
	
	
	hi Lisa,
	 
	I think that diable iff should not change the status from
sequence to property.  
	 
	 Also, sequence expression could be restricted to sequence
instance, to make it clear from the definition that it is a sequence. 
	 
	Best regards,
	ed
	 


________________________________

		From: owner-sv-ac@eda.org [mailto:owner-sv-ac@eda.org]
On Behalf Of Lisa Piper
		Sent: Monday, May 07, 2007 2:02 PM
		To: sv-ac@eda.org
		Subject: [sv-ac] Statistics counters proposal
		
		
		Hi all,

		 

		I would like to get early feedback on a proposal  that I
am writing to clarify the statistic counters that are associated with
assertions. The current chapter 17 LRM specifies that these counters
must exist for cover statements only, yet 29.1.2 text is written as
though all counters are available for all assertions.  I think there is
value in having the statistic counters for all assertions. For assert
and assume statements, it may be useful to know the number of failures
and passes. A failure indicates a bug of some kind while a pass is
confirmation that the stimulus tested the behavior. For cover
properties, only the number of non-vacuous passes may be of
significance. 

		 

		I would like to propose that a minimal set of pass/fail
counts be required for all assertions (immediate and concurrent), and
that others can be optionally provided if desired.  And only the pass
counter is required for cover properties (others are optional).  Are
there any objections to this principal?

		 

		 The other part of the proposal is to clarify how to
distinguish a property_spec from a sequence_expr. (this is Mantis 1768)
A property_spec that is just a single sequence_expr shall be interpreted
as a sequence, whereas a property_spec that is not just a sequence_expr
shall be interpreted as a property.  For example, an expression that
contains an implication operator or a disable iff term, is considered a
property. A property instance that is just a single sequence_expr is
interpreted as a sequence (assuming there is not any default disable iff
clause).  Does this sound ok?

		 

		Lisa


		-- 
		This message has been scanned for viruses and 
		dangerous content by MailScanner
<http://www.mailscanner.info/> , and is 
		believed to be clean. 


-- 
This message has been scanned for viruses and
dangerous content by MailScanner, and is
believed to be clean.