RE: [sv-ec] RE: [sv-bc] Covergroup Clocking Event?

Cliff,

I agree with Dave's response. The intent as captured by the BNF was to
not restrict the
type of event expression in any way. However, if users should be
cautious when adding
OR expressions to a coverage group event because the event may trigger
multiple times
within the same time step. This might lead to racy behavior or, as is
more likely to be the
case, to overestimated bin counts. In these situations it might be a
good idea to consider
the use of the "strobe" option.

	Arturo

-----Original Message-----
From: owner-sv-ec@eda.org [mailto:owner-sv-ec@eda.org] On Behalf Of
Rich, Dave
Sent: Wednesday, March 01, 2006 2:00 PM
To: sv-ec@eda.org
Subject: [sv-ec] RE: [sv-bc] Covergroup Clocking Event?

The BNF states what is legal and the LRM text does not state any
restrictions.

coverage_event ::=
	clocking_event
	| @@( block_event_expression )

clocking_event ::=
	@ identifier
	| @ ( event_expression )

event_expression ::=
	[ edge_identifier ] expression [ iff expression ]
	| sequence_instance [ iff expression ]
	| event_expression or event_expression
	| event_expression , event_expression

> -----Original Message-----
> From: owner-sv-bc@eda.org [mailto:owner-sv-bc@eda.org] On Behalf Of
Cliff
> Cummings
> Sent: Wednesday, March 01, 2006 1:45 PM
> To: sv-bc@eda.org
> Subject: [sv-bc] Covergroup Clocking Event?
> 
> Hi, All -
> 
> A couple of us were trying to determine if a covergroup clocking event
> could be a multi-event statement, such as:
> 
> covergroup cg1 @(a or b or posedge c); ...
> 
> A quick search of the LRM did not show any similar examples, but we
also
> did not find any specific prohibitions listed anywhere. Does anyone
have
> and answer or could anyone point us to the section that describes the
> prohibition?
> 
> Thanks - Cliff