Re: Hierarchical reference questions

From: Jonathan David <jb_david_at_.....>
Date: Fri Dec 08 2006 - 00:45:36 PST
sorry, sent private response only to Marq, 
to the effect that I was trying to clarify the implications, 
not complaining about them. 
you would have to coerce to contribute.. if your test bench needs to do it, "casting" 
would be the wrong thing to do anyway.. 

Casting gives you the flexibility to access it either as analog or logical in different places in the same module.. 

Jonathan

 
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: Marq Kole <marq.kole_ f rom _nxp.com>
To: verilog-ams <verilog-ams_ f rom _eda-stds.org>
Sent: Friday, December 8, 2006 12:26:09 AM
Subject: Re: Hierarchical reference questions



Jonathan,



Yeah, but for contribution you probably
want the contributing OOMR signal to be part of the discipline resolution
for the whole design, while for RHS that is not really needed. To put it
in another way: for contribution you actually want the behavior of the
design to change, while for reading/probing (again considering the test
bench use) you do not want a different behavior because of the reading/probing.



Cheers,

Marq





Marq Kole

Competence Leader Robust Design



Research

NXP Semiconductors




















Jonathan David <jb_david_ f rom _yahoo.com>

08-12-2006 08:08





To

Marq Kole <marq.kole_ f rom _nxp.com>

verilog-ams <verilog-ams_ f rom _eda-stds.org>


cc





Subject

Re: Hierarchical reference questions


Classification




















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

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: 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 Fri Dec 8 00:45:42 2006

This archive was generated by hypermail 2.1.8 : Fri Dec 08 2006 - 00:45:44 PST