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Unable to simulate Verilog Testbench - 'lic_error-18'

anmos

Hi,

I am trying to simulate a simple AND gate written in Verilog, using NCLaunch.
The code for my gate is the following (andgate.v):

`timescale 1 ns / 1 ns
/* A simple AND gate
File: andgate.v              */

module andgate (a, b, y);
input a, b;
output y;

assign y = a & b;

endmodule

The code for my test bench is the following (andgate_tb.v):


`timescale 1 ns / 1 ns
/* testbench for AND gate
File: andgate_tb.v */

module andgate_tb;
wire t_y;
reg t_a, t_b;

andgate my_gate( .a(t_a), .b(t_b), .y(t_y) );
initial
begin

    $monitor(t_a, t_b, t_y);

    t_a = 1'b0;
    t_b = 1'b0;

    #5
    t_a = 1'b0;
    t_b = 1'b1;

    #5
    t_a = 1'b1;
    t_b = 1'b0;

    #5
    t_a = 1'b1;
    t_b = 1'b1;

end

endmodule

In NCLaunch, I manage to compile both the andgate.v and andgate_tb.v files without errors (using ncvlog). I also use the elaborator on my top file which is andgate_tb, in order to create the necessary snapshot.

Unfortunately when I choose the created snapshot and press the "Launch Simulator with current selection" button, the simulator fails to be invoked giving me the following error:

"ncsim: *F,NOLICN: Unable to checkout license for the simulation. Use ncsim -MESSAGES for more information. (flag - 2) 'lic_error -18'."

When I execute the "ncsim -MESSAGES" command, I get the following information:

" ncsim: *F,MISSIM: Missing simulation name."

Is this a license problem, meaning that I don't have the necessary licanse to run the simulator? This is strange as I am perfectly able to open without any problem the SimVision simulator.

Can you please provide me some help on how to simulate my test bench?

Thank you in advance for your feedback and help!

P.S.
I am following the guidelines in the NCLaunch User Guide (NCLaunch User Guide
Product Version 14.1 June 2014). I tried the same with the example tutorials that are provided by Cadence, but still I get the same error.

  • I forgot to mention that the version that I am using for all the above tools (Simvision, NCLaunch, NCVerilog, NCSim) is the 15.20-s052 64-bit.

  • The NOLICN error suggests that the tool was not able to checkout a license. Please check if the CDS_LIC_FILE or LM_LICENSE file variable is set correctly, pointing to the license server.

  • in reply to muffi

    Hi muffl and really thanks for your reply!

    Since all the above tools are opening in stand alone mode, without giving any error, those files variables must be set correctly (otherwise the tools won't open).
    Any other ideas on what might be the problem?

    Any thoughts on the " ncsim: *F,MISSIM: Missing simulation name." message?

  • in reply to anmos

    The missing simulation name comes from the that that you took the "Use ncsim -MESSAGES for more information" message too literally! :) When you run ncsim, you have to give it a simulation snapshot name for it to execute. The -message switch is simply asking ncsim to print more detailed messages during run time.

    Unless you have a strong need to use nclaunch, I would recommend using the "irun" command to manage your compilation and simulation. Broadly speaking, to compile and elaborate:

    irun andgate.v andgate_tb.v -elaborate

    Then to simulate:

    irun -R [-gui]

    If you still get licence error messages, check that your shell has the CDS_LIC_FILE variable set and that it points to the right licence servers. You could also try doing "setenv FLEXLM_DIAGNOSTICS 3" before trying to run the simulation, this should result in detailed messages about how the simulator is trying to find the licence.

    Note that the compiler and elaborator don't look for a licence, it's only when you try to run simulation that the licence is checkd for, so Muffi's question is totally valid and you need to check that rather than ignoring his advice.

  • in reply to StephenH

    The irun command didn't do the trick also. I still got the same error. Apparently as you correctly stated, the stand alone opening of the tools is not a sign that a license exists and only when you try to run a simulation the licence is checked. It turned out that we didn't have a license.
    Thank you again very much for your quick responses and , your help is much appreciated!

    Kind regards,
    Nassos

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