Re: [sv-ec] Arrays of events

Thanks, Shalom.  So the SV BNF should be as follows?
 
event_trigger ::=

    -> hierarchical_event_identifier bit_select ;

 | ->> [ delay_or_event_control ] hierarchical_event_identifier
bit_select ;

 

Also, according to 4.8, the initial value "can be another event variable
or the special value null". 

 

Can the initial value of an event array be expressed with an assignment
pattern, another event array, or a slice of another event array?

 

Can null be the initial value for an entire array of events, too, or
must null be assigned to each element of the event array for which a new
synchronization object is not desired?

 

-- Brad


________________________________

From: owner-sv-ec@eda.org [mailto:owner-sv-ec@eda.org] On Behalf Of
Bresticker, Shalom
Sent: Wednesday, September 13, 2006 2:04 AM
To: Rich, Dave; sv-ec@eda-stds.org
Subject: RE: [sv-ec] Arrays of events



Dave,

 

The LRM allows you to declare an array of event:

 

event a [3:0]; 

 

but the syntax doesn't seem to allow  you to trigger on an element of
the event array:

 

-> a[0];

 

Is this simply a BNF oversight or is this an intentional omission. Seems
to me that if you can declare an array of events, you should be able to
trigger an element of an array.

 

[SB] In 1364-2005, issue BTF 67 fixed this:

http://boyd.com/1364_btf/report/full_pr/67.html

 

The fixed syntax is found in 1364-2005 in Syntax 9-10 in 9.7.3 and in
A.6.5.:

 

event_trigger ::= 

-> hierarchical_event_identifier { [ expression ] } ;

 

 

However, this change seems to have been omitted from 1800. Syntax 14-1
there is:

 

event_trigger ::=

    -> hierarchical_event_identifier ;

 | ->> [ delay_or_event_control ] hierarchical_event_identifier ;

// from A.6.5

 

So the change should be there in both the blocking and nonblocking event
trigger.

 

The syntax descriptions in 14.5.3 and 14.5.4 would have to change as
well.

 

I filed Mantis 1585 on this.

 

One more point:

 

http://boydtechinc.com/etf/archive/etf_2003/1021.html asked why the
event_control form 

  @ hierarchical_event_identifier 

should not be

  @ hierarchical_event_identifier { "[" expression "]" } . 

 

The answer is not recorded, but that change was not made, so presumably
it was decided that waiting on an element of an event array would
require parentheses.

 

Shalom