RE: [sv-ec] Mantis 1330/1742: semantics unclear?

Stu has more than enough authority as the editor to make corrections
like this on his own, without Mantis and formal votes. 

-- Brad 

-----Original Message-----
From: owner-sv-ec@eda.org [mailto:owner-sv-ec@eda.org] On Behalf Of
Rich, Dave
Sent: Thursday, January 10, 2008 9:45 AM
To: Jonathan Bromley; sv-ec@eda.org
Subject: RE: [sv-ec] Mantis 1330/1742: semantics unclear?

Probably the correct IEEE-ese grammar should be

"An interface instance or virtual interface with no modport selected may
be assigned to a virtual interface with a modport selected"


The example should be

v32_phy = p32; // legal assignment from no selected modport to
               // selected modport


I think we should just create a mantis issue as an editorial change.


> -----Original Message-----
> From: owner-sv-ec@server.eda.org [mailto:owner-sv-ec@server.eda.org]
On
> Behalf Of Jonathan Bromley
> Sent: Thursday, January 10, 2008 3:26 AM
> To: sv-ec@server.eda.org
> Subject: [sv-ec] Mantis 1330/1742: semantics unclear?
> 
> hi EC,
> 
> I have a problem with the meaning of some of the rules about virtual 
> interfaces as modified by Mantis 1330.
> 
> The following sentence is somewhat opaque:
> 
>   It shall be legal to assign to a virtual interface with
>   a modport selected from an interface instance or virtual
>   interface with no modport selected.
> 
> The examples towards the end of 24.9 help a little:
> 
>   v16_phy = v16; // legal assignment from no selected
>                  // modport to selected modport
>   v16 = v16_phy; // illegal assignment from selected modport to
>                  // no selected modport
> 
> but the semantics of "v16_phy = v16;" are poorly specified - having 
> made the assignment, is access to "v16_phy.something"
> restricted by the modport (as per v16_phy's declaration) or is it just

> an access through the interface (as per the actual contents of 
> v16_phy, a reference to the whole interface)?
> I'm guessing it's the former, by analogy with the semantics of 
> connecting an interface port and to facilitate compile-time checking 
> of the legality of accesses.
> 
> Finally, the comment seems wrong on this part of the examples:
> 
>   v32_phy = p32.phy; // legal assignment from no selected modport to
>                  // selected modport
> 
> Surely "p32.phy" indeed *has* a selected modport?
> --
> Jonathan Bromley, Consultant
> 
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