I'm trying to run V-AMS codes on SimVision in Cadence...i give my sine wave input as:

vsource #(.type("sine"),.dc(0),.amp(5),.val1(5),.val0(-5),.freq(5000)) vin(in,gnd);

now i see a sine wave as an input but it has an amplitude of only 1volt...iv tried everything possible..what could be wrong?

also,how can i get layout designs for v-ams codes which function properly?is there an option in simvision or any other tool that i can use to get a ciruit layout for a given code?

lastly,the testbenches for the sample codes on this website seem to be written out for spectre. is this a better tool than simvision?

i'd reallly like to learn from a verilog ams tutorial, if there is one online....resources seem to be very limited save this book and the LRM !!!

thanks again!

vikram

Hi Ken

Thanks a LOT ! That was really helpful. I'm going to use the "Designer's guide" to learn Verilog-AMS completely..and it seems like SimVision might be the best tool for me to complie my codes.  

Now when you say that this tool can simulate  Verilog-AMS programs...can it just complie them or can it produce a blck diagram layout of the same too? I dont know if my question is specific enough,but I'd like to see circuit layouts drawn by SimVision for the circuit codes that I compile.

Actually the simvision debugging environment has a schematic tracer which allows you to visualize the connections for selected instances and nets in your Verilog code.

You can select nets/instances in the browser (either the design browser or the code browser, say), and then "send to schematic tracer" (I think that's what the menu says).

Note, this is not a _real_ schematic - just a virtual representation of one in order to allow you to figure out signal flow.

In the DFII environment, there is File->Import->Verilog which would allow you to create a real schematic from structural Verilog (any behavioural blocks will be imported as textual views).

From what you said, I think this is what you were after; if you were after physical layout, then that's the job of a place and route tool (such as the Encounter family from Cadence).

Regards,

Andrew.

Hi Andrew and Ken

Thanks for letting me know about the schematic tool for AMS-Design Browser. I tried my resistor code to see what kind of simulation I got... The following are the codes:

Resistor:
`include "disciplines.vams"
`include "constants.vams"
`timescale 10ps/1ps;


module res(pos,neg);
parameter real rn=1k from [0:inf] exclude 0;
electrical pos,neg;
analog
begin
V(pos,neg) <+ rn*I(pos,neg);
end
endmodule

TESTBENCH:
`include "disciplines.vams"
`include "constants.vams"
`timescale 10ps/1ps

module resistortest(p,n);
ground n;
electrical p,n;
res #(rn(100)) resistor(p,n);
vsource#(.type("sine"),.ampl(5),.freq(5000),.dc(0))vin(p,n);
endmodule

Now when I complie this, I see a sine wave for the pos terminal and just a straight line output for neg terminal. The Schematic tool shows that 0 signal comes out of the device from the neg terminal.

Am I doing something wrong?

How can I get V-I characteristics instead of getting Voltage characteristics w.r.t Time?

Vikram