Re: Scope of 'ground' discipline

Hi Paul,
I believe the example of sigmadelta is incomplete. The net discipline
declaration should be at the same scope. So the example in sigmadelta should be:

electrical gnd;
ground gnd;

I will raise a single Mantis item to capture all these errors you have reported
over the last few days.

Cheers...
Dave

On 02/03/2011 08:16 AM, Paul Floyd wrote:
> Hi
>
> In this paragraph
>
> "3.6.4 Ground declaration
> Each ground declaration is associated with an already declared net of
> continuous discipline. The node associated
> with the net will be the global reference node in the circuit. The net must be
> assigned a continuous
> discipline to be declared ground."
>
> ground declarations have to be associated with continuous disciplines. It
> doesn't explicitly state whether the association need be done at the same scope
> as the ground declaration or not. In the example below (from 6.2.2), the
> association for ground in module sigmadelta is done in the instantation C2 of
> comparator, which to me implies that the association need not be at the same
> scope.
>
> Do you think that it should be explicitly stated in the LRM that the scope of
> the association can be different? Alternatively, if the scope of the
> association should be the same as the gound declaration, there is an error in
> the example below.
>
> module comparator(cout, inp, inm);
> output cout;
> input inp, inm;
> electrical cout, inp, inm;
> parameter real td = 1n, tr = 1n, tf = 1n;
> real vcout;
>
> analog begin
> @(cross(V(inp) - V(inm), 0))
> vcout = ((V(inp) > V(inm)) ? 1 : 0);
> V(cout) <+ transition(vcout, td, tr, tf);
> end
> endmodule
>
> module integrator(out, in);
> output out;
> input in;
> electrical in, out;
> parameter real gain = 1.0;
> parameter real ic = 0.0;
>
> analog begin
> V(out) <+ gain*idt(V(in), ic);
> end
> endmodule
>
> module sigmadelta(out, aref, in);
> output out;
> input aref, in;
> ground gnd;
> comparator C1(.cout(aa0), .inp(in), .inm(aa2));
> integrator #(1.0) I1(.out(aa1), .in(aa0));
> comparator C2(out, aa1, gnd);
> d2a #(.width(1)) D1(aa2, aref, out); // a D/A converter
> endmodule
>
>
> Regards
> Paul Floyd

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