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Design Languages >> Verilog-AMS >> Query with regard to contribution operator
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Message started by Rosh on Jun 28^th, 2016, 12:12am

Title: Query with regard to contribution operator
Post by Rosh on Jun 28^th, 2016, 12:12am

Here is my code :

Code:

`include "disciplines.vams"

module test(in, out);
input in;
output out;
voltage out,in;
analog begin
if (V(in)==0)
V(out)<+1;
else
V(out)<+3;

V(out)<+1;

end

endmodule

This is the resulting output

In the first edge:
In=5V and Out=4V

In the second edge:
In=0V and Out=2V instead of 6V.

Since the contribution operator accumulates signal values, shouldn't Out have a potential of 6V? (4V from the previous edge)

Title: Re: Query with regard to contribution operator
Post by Ken Kundert on Jun 28^th, 2016, 11:57am

The contribution operator does not accumulate over time. It adds together all of the contributions made to a branch at each instant in time. The starting point at each instant of time is not the previous value, it is always zero.

I recommend you take a look at this tutorial.

-Ken