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Altera_Forum
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14 years ago

# Invalid time string specified: in ModelSim

I'm using ModelSim Altera Starter Edition 6.6 for simulating some very simple designs. I started a new project, compiled and everything was ok. But when I had wanted to start simulation, I have opened the wave window and all I get is:# Invalid time string specified: and the wave window is just a big grey window.

Even an other project that I had already simulated stopped working. I tried deleting some configuration files and nothing. I reinstalled the whole software and still nothing.

Searching on google and on the forums I even found some threads of people with similar problems, but none got a solution.

And I wanted also to ask why Altera changed the simulator integrated in Quartus II 9.1 for ModelSim. I used the 9.1 version for a while and it was so much easier to simulate. What does ModelSim offer that Quartus couldn't handle?

Thanks,

Daniel K. Franch

18 Replies

  • Altera_Forum's avatar
    Altera_Forum
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    14 years ago

    --- Quote Start ---

    # Invalid time string specified

    --- Quote End ---

    If you are simulating Verilog, then try adding '-t ps' to the vsim command line to set the timescale to 1ps. You might also want to add something like

    `timescale 1 ps / 1 ps

    to your Verilog.

    --- Quote Start ---

    What does ModelSim offer that Quartus couldn't handle?

    --- Quote End ---

    A programmable method of generating a testbench. Drawing stimulus waveforms works for only the simplest of testbenches.

    Cheers,

    Dave
  • Altera_Forum's avatar
    Altera_Forum
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    14 years ago

    you should also get more stimulus reuse when using HDL/C/etc test benches

  • Altera_Forum's avatar
    Altera_Forum
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    14 years ago

    Actually, I'm simulating VHDL. I tried adding -t ps to the command line, but it didn't work. It still gives me that message and a grey window when I try to open the wave window.

    I guess as I am testing very simple projects, ModelSim seems over-complicated to me. But I probably should learn how to use it know, for it will be easier when I try to simulate more complex projects.
  • Altera_Forum's avatar
    Altera_Forum
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    14 years ago

    --- Quote Start ---

    I'm simulating VHDL.

    --- Quote End ---

    Post your code.

    --- Quote Start ---

    I guess as I am testing very simple projects, ModelSim seems over-complicated to me. But I probably should learn how to use it know, for it will be easier when I try to simulate more complex projects.

    --- Quote End ---

    Its worth learning.

    There's an example at this thread you can use:

    http://www.alteraforum.com/forum/showthread.php?t=32386

    Cheers,

    Dave
  • Altera_Forum's avatar
    Altera_Forum
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    14 years ago

    My code is the following: 

    
entity ex_or is
 port(a,b,c,d : in bit;
		x,y,z : out bit);
end ex_or;
architecture a of ex_or is
begin
	x <= a xor b;
	y <= a xor b xor c xor d;
	z <= (a and b) xor (c and d);
end a;

    It is just an exercise from a Digital Electronic book, from the chapter of XOR gates. I'm just trying to get used with VHDL.

    I already simulated an equally simple code to test AND and OR gates and it worked yesterday. But when I try to do it now, I get the same result.

    I will take a look in this example, it seems useful. Thanks.

    ---

    Edit: I just tried the example and got the same thing: Invalid time string specified, grey wave window. It doesn't seem to be something with code, but in some configuration or command.
  • Altera_Forum's avatar
    Altera_Forum
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    14 years ago

    Don't use the same architecture name as a signal or port or component name.

    Cheers,

    Dave
  • Altera_Forum's avatar
    Altera_Forum
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    14 years ago

    --- Quote Start ---

    Just changed that, but still no luck.

    --- Quote End ---

    Try the modelsim simulation I sent you the link to. See if that works.

    That'll at least tell you the tools are setup ok.

    Cheers,

    Dave
  • Altera_Forum's avatar
    Altera_Forum
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    14 years ago

    --- Quote Start ---

    Try the modelsim simulation I sent you the link to. See if that works.

    --- Quote End ---

    I used your simulation, just as it was described on the readme file, and got the grey wave window all over again.

    --- Quote Start ---

    That'll at least tell you the tools are setup ok.

    --- Quote End ---

    So the problem probably isn't the code, but the tools?
  • Altera_Forum's avatar
    Altera_Forum
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    14 years ago

    --- Quote Start ---

    I used your simulation, just as it was described on the readme file, and got the grey wave window all over again.

    So the problem probably isn't the code, but the tools?

    --- Quote End ---

    Sounds like it.

    When you get a grey wave window, do you get the time string error?

    Cheers,

    Dave