RE: [sv-ac] Mantis 1698

I meant clk as a generic term, probably would have to be rewritten to
the acceptable form in each case. 
ed 

> -----Original Message-----
> From: Thomas.Thatcher@Sun.COM [mailto:Thomas.Thatcher@Sun.COM] 
> Sent: Tuesday, January 29, 2008 3:50 PM
> To: Eduard Cerny
> Cc: sv-ac@eda.org
> Subject: Re: [sv-ac] Mantis 1698
> 
> Hi Ed,
> 
> What we could say is that the LOGICAL equivalent is
> always @clk past_variable <= $sampled(x);
> 
> The timing is different, and in addition, that @clk is not 
> considered an 
> edge-triggered specification.  It would be inferred as a 
> buffer, not a 
> flip-flop.
> 
> Tom
> 
> Eduard Cerny wrote:
> > Hi to start the discussion, I copy here the note I put on 
> mantis 1698
> > quite a while ago. Could that be used?
> > 
> > ---
> > Regardless where $past(x,,,@clk) is called from, the RTL 
> equivalent is
> > 
> > always @clk past_variable <= $sampled(x);
> > 
> > and executes in the active region.
> > 
> > If $past is called from active, reactive or observed 
> regions, replace
> > the call by $sampled(past_variable).
> > 
> > In synthesized code which executes in the active region, use the
> > past_variable directly. Provided that the model follows 
> synthesis rules
> > and is not racy, the behavior should be equivalent to that in the
> > original model using $past.
> > 
> > The other functions, $rose, $fell and $stable would follow. 
> > 
> > ----
> > 
> > Best...
> > ed
> > 
> 

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