Re: Implicit nets and its empty discipline

Subject: Re: Implicit nets and its empty discipline
From: Jonathan Sanders (jons@cadence.com)
Date: Fri Feb 07 2003 - 00:07:03 PST

Graham,

These nets have no domain and no discipline and they are resolved during discipline resolution.  There is really no discipline here (it is a pseudo discipline) but a placeholder for discipline resolution.   If you remember in the older version of the LRM it had:

It is possible to define a discipline with no nature bindings. These are known as empty disciplines and they can be used in structural descriptions to let the components connected to a net determine which natures are to be used for the net. Such disciplines may have a domain binding or they may be domain-less, thus allowing the domain to be determined by the connectivity of the net.
Examples:
discipline neutral
enddiscipline


I am not completely sure why the paragraph was changed but semantically there was not real change.   If you look at the old LRM what it showed can still be done today but we really needed an implicit interconnect discipline.  We use wire as the interconnect but the point here is that in Verilog for scalar nets they do not need to be declared as anything (even wire).

Jon



At 07:57 PM 2/6/2003, Graham Helwig wrote:
Hello,

In section 3.4.6 of the Verilog-AMS LRM version 2.0 and section 3.4.5 of
the Verilog-AMS LRM version 2.1, implicit nets are defined to be scalar
with an empty (domainless) discipline bound to it. Where is this
discipline defined? Should it be defined in disciplines.vams? What is
the name of the empty domainless discipline (i.e. wire, neutral,
interconnect, etc)?

Regards
Graham

 
-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-
Graham Helwig                   email: A11558@email.mot.com
                                       ghelwig@asc.corp.mot.com
Telephone:+61-8-81683532        Fax:+61-8-81683501
Motorola Australia Software Centre,
2 Second Avenue, Mawson Lakes, Adelaide, SA, 5095, Australia
-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-

***********************************************************
Jonathan L. Sanders                  
Product Engineering Director
Custom IC Solutions
Cadence Design Systems, Inc.     
555 River Oaks Pkwy
San Jose, CA. 95134
 INTERNET:jons@cadence.com    Tel: (408) 428-5654      Fax : (408) 944-7027
***********************************************************

This archive was generated by hypermail 2b28 : Fri Feb 07 2003 - 00:23:35 PST