Re: [sv-ac] RE: sv-ac 1531

Hi Ed:

Another alternative is to have the user declare the variable
outside of the sequence or property and then allow the local 
variable assignment syntax to be used for assigning to the 
external variable.

This way of doing things allows one property to move information 
to another property, not just one attempt of a property moving
information to another attempt of the same property.

I think this way of doing things also makes it less important to
account for the update to the external variable in the formal
semantics of the assertions.

I think that in any case, multiple updates to the static variable
in the same timestep will execute in non-deterministic order.

I agree with Doron that the initialization should be added for
all local variables.  This enhancement was requested a long time
ago.

J.H.

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> Doron,
> 
> I would be for leaving the semantics as loose as possible, in other
> words, if the user writes to a global variable from two parallel
> processes, there is nothing in the language to stop him/her. Why do we
> have to policy it in the assertios? As I said earlier, if I use tasks, I
> can do this today, but it is cumbersome. 
> 
> ed
>  
> 
> > -----Original Message-----
> > From: Doron Bustan [mailto:dbustan@freescale.com] 
> > Sent: Thursday, July 13, 2006 6:27 PM
> > To: Eduard Cerny
> > Cc: sv-ac@eda-stds.org
> > Subject: sv-ac 1531
> > 
> > Ed,
> > 
> > we need a  definition of a semantic for static local variables.
> > In particular it make sense to define different flow rules
> > for static local variables.
> > 
> > for example
> > 
> > property p1;
> > logic [3:0] v;
> > 
> > ((a, v = 1) or (b, v=2)) ##1 (v == 1);
> > endproperty
> > 
> > is legal, but
> > 
> > property p2;
> > static logic [3:0] v;
> > 
> > ((a, v = 1) or (b, v=2)) ##1 (v == 1);
> > endproperty
> > 
> > probably should not be legal, because the value of v flowing 
> > out of ((a, 
> > v = 1) or (b, v=2)) is undefined.
> > 
> > BTW, I think that initialization should be in a separate proposal.
> > 
> > Doron
> > 
>