resolveto statement's discipline list constraint


Subject: resolveto statement's discipline list constraint
From: Graham Helwig (ghelwig@asc.corp.mot.com)
Date: Wed Jan 16 2002 - 14:53:00 PST


Hello,

Based on the LRM conference call on 15 jan 2002, the following email
with examples has been sent. This discussion started with a question why
the disciplines of the discipline resolution connect statement (section
8.7.2 LRM version 2.0) is constrained to be compatible with each other.
This prevents discipline resolution connect statement like below to
occur:

        connect cmos1 electrical logic resolveto cmos1;
        connect kinematic electrical mechanical resolveto mechanical;

According to section 8.4.4, it is assumed that continuous nets have
precedence over discrete nets. This applies to both basic and detailed
discipline resolution algorithms.

During the conference call it was discussed whether the LRM should have
such a constraint within the discipline resolution connect statement,
and
actually be able to allow the connect statements described above to be
legal.
By doing this the LRM defined net domain precedence is overridden
with an user defined precedence via the discipline resolution connect
statement(s). This then allows the discipline resolution and ACMI
mechanism to be extended into multidisciplinary continuous Verilog-AMS
description.

The following examples and scenarios illustrate the above explanation
further.

Example 1:

        module m1;
                m2 i1(n);
                m3 i2(n);
        endmodule

        module m2(a);
                input a;
                electrical a;
                ...
        endmodule

        module m3(d);
                output d;
                logic d;
                ...
        endmodule

Example 2:

        module k1;
                k2 i1(n);
                k3 i2(n);
        endmodule

        module k2(e);
                input e;
                electrical e;
                ...
        endmodule

        module k3(m);
                output m;
                mechanical m;
                ...
        endmodule

Since the nets m1.n and k1.n is implicit then its discipline must be
resolved before determining the need for ACMI (assuming the basic
method is used). The following scenarios illustrate how these undeclared
nets will resolved:

Scenario 1:
        Using example 1 and the following discipline resolveto statement
        the net m1.n is resolved to be electrical.

                connect electrical logic resolveto electrical;

Scenario 2:
        Using example 1 and the following discipline resolveto statement
        the net m1.n is resolved to be logic.

                connect electrical logic resolveto logic.

Scenario 3:
        Using example 2 and the following discipline resolveto statement
        the net m1.n is resolved to be electrical.

                connect mechanical electrical resolveto electrical;

Scenario 4:
        Using example 2 and the following discipline resolveto statement
        the net m1.n is resolved to be mechanical.

                connect mechanical electrical resolveto mechanical;

-- 
-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-
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
-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-



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