Re: Hierarchical reference questions

From: Jonathan David <jb_david_at_.....>
Date: Thu Dec 07 2006 - 23:08:40 PST
One implication of this is that its ONLY for RHS expressions.. 
you'd have to Coerce to do a heirarchical contribution. 
But it does seem more flexible

 
Jonathan David
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jb_david_ f rom _yahoo.com
http://ieee-jbdavid.blogspot.com
Mobile 408 390 2425
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408 200-7024

----- Original Message ----
From: Marq Kole <marq.kole_ f rom _nxp.com>
To: verilog-ams <verilog-ams_ f rom _eda-stds.org>
Sent: Thursday, December 7, 2006 10:37:55 PM
Subject: RE: Hierarchical reference questions



Martin,



Instead of the proposed "useas"
keyword would you suggest that we can also fit the casting operation to
our needs? So for Graham's example:



    myDesign system(.....);

    //electrical system.inst.inst.net;  // not needed

    //logic system.inst.net;          
 // not needed

    analog $display("Value is %g.", V(electrical'(system.inst.inst.net)));

    initial $display("Value is %b.", logic'(system.inst.net));



As a way to handle OOMR I like this
better than the "useas" keyword.



Cheers,

Marq

 



Marq Kole

Competence Leader Robust Design



Research

NXP Semiconductors






















"Martin O'Leary" <oleary_ f rom _cadence.com>

Sent by:

owner-verilog-ams_ f rom _server.eda.org

08-12-2006 07:06





To

"Jonathan David" <jb_david_ f rom _yahoo.com>

"Graham Helwig" <graham.helwig_ f rom _astc-design.com>

"Verilog-AMS Reflector" <verilog-ams_ f rom _server.eda.org>


cc





Subject

RE: Hierarchical reference questions


Classification




















FYI



Here is something from section 4.14 "Casting" of SystemVerilog
that

talks about how casting is done in that language.



> A data type can be changed by using a cast ( ' ) operation. In a

static cast, the expression to be cast

> shall be enclosed in parentheses that are prefixed with the casting

type and an apostrophe. If the

> expression is assignment

> compatible with the casting type, then the cast shall return the value

that a variable of the casting

> type would hold after being assigned the expression. If the expression

is not assignment compatible

> with the casting type, then if the casting type is an enumerated type,

the behavior shall be as

> described as in 4.15, and if the casting type is a bit-stream type,

the behavior shall be as

> described in 4.16.



Here is an example of how a real expression is cast to an int.



> int'(2.0 * 3.0) 



Thanks,

--Martin



-----Original Message-----

From: owner-verilog-ams_ f rom _eda.org [mailto:owner-verilog-ams_ f rom _eda.org] On

Behalf Of Jonathan David

Sent: Thursday, December 07, 2006 9:55 PM

To: Graham Helwig; Verilog-AMS Reflector

Subject: Re: Hierarchical reference questions



I'll propose that we add a keyword "useas"



useas ''discipline_name'' hier.net.reference.to.net;



with the "useas" declaration, the net would not Actually be coerced
to

this discipline, we'd get an interface element instead.. 



One idea from tonights meeting.





 

Jonathan David

j.david_ f rom _ieee.org

jb_david_ f rom _yahoo.com

http://ieee-jbdavid.blogspot.com

Mobile 408 390 2425

Work:

jbdavid_ f rom _scintera.com

http://www.scintera.com

408 200-7024



----- Original Message ----

From: Graham Helwig <graham.helwig_ f rom _astc-design.com>

To: Verilog-AMS Reflector <verilog-ams_ f rom _eda.org>

Sent: Wednesday, December 6, 2006 11:46:38 PM

Subject: Hierarchical reference questions



Hello,



When simulating large mixed-signal design (containing transistors and

gates) I have had the need to hierarchically reference an implicit net

with the design. Also the resolved domain of the net is not known and

even if it is known it may change from one simulation to the next.



I may of missed in the LRM, but is hierarchical referencing of an

implicit nets allowed in the language?



If it is, then does the net need to be coerced to the same domain as the

probe or does discipline resolution and ACMI resolves handle the

resolution of the implicit net including any hierarchical references to

that net?



For example:



    myDesign system(.....);

    electrical system.inst.inst.net;  // is this required?

    logic system.inst.net;          
 // is this required?

    analog $display("Value is %g.", V(system.inst.inst.net));

    initial $display("Value is %b.", system.inst.net);



Regards

Graham







--

==========================================================

Graham Helwig

AMS Verification

Australian Semiconductor Technology Company (ASTC) Pty Ltd



Location: 76 Waymouth St, Adelaide, SA, 5000, Australia

Phone     +61-8-82312782

Moblie:   +61-4-03395909 

Email:    graham.helwig_ f rom _astc-design.com

Web:      www.astc-design.com

==========================================================




















Received on Thu Dec 7 23:08:45 2006

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