Scripting your test stimulus can be fairly easy yet powerful option, and you can get this going quickly. Make sure to open the Wave Viewer (or specify it in TCL command). Once it completes this process, the wave viewer is updated with the waveform response. Once you run all the statements to operate on your signals and indicate which signals you want to view, you tell ModelSim to "run" some number of time steps. Plus, as an interactive scripting tool, you get immediate feedback from ModelSim if you have an error (error messages). When you submit your script statements to ModelSim, it executes them internally depending on the complexity of your stimulus algorithm, it can take many seconds to run before the vsim> prompt comes back.remember to be patient. You would also likely have some set of statements before all the ones I've listed that would do signal initialization, any looping to increment counters, etc., and send signals at periodic times, and also perform offset calculations. I'm not going to describe the TCL syntax or statement semantics this is something you can look up online (and everything in Quartus uses TCL scripting in the background, so it's a good thing to learn). run simulation for some number of cycles: assign values to inputs at start time and at time offsets:ĥ. Here are some of the typical TCL commands for building a stimulus file (I've removed my design hierarchy information, so all you see if the signal name):įorce -freeze sim:/CLK 1 0, 0 -r 50Ĥ. Let me ad this.I should also say that the contents of the Wave View can be managed by scripting as well. It doesn't require as much work as writing a full-blown TestBench, but is likely more flexible than drawing waveforms. Using the stimulus scripting is another option to consider. I did a web search on example files, and I can post some of the commands I used, if this is of interest. There is a method of having ModelSim read a TCL stimulus command file, but I've not needed to use that, since I may be spending a lot of time exploring how I want to conduct the testing itself. This allows you to assign values to your inputs (including clock and reset), to turn them on and off at set times, advance the time wheel, and make variable updates to control the time points when you want events to take place.īefore I created a full-blown VHDL TestBench, I wrote text files filled with TCL script statements, and then would feed these into the ModelSim command line located at the bottom of the display using copy/paste with the mouse. One other method to start with a test stimulus of your design is to write commands in TCL and submit these on the ModelSim command line. Run some of these tests, and you'll see how the simulation-only stimulus 'creates' waveforms that interact with the synthesizeable logic.
I've posted some very simple examples in these threads:Īnd a more complicated example in this Wiki page However, as you gain more experience with the tool, you will find that what you really need to create is a model of the device you are interfacing. Since you are just starting to use Modelsim, let me give you some advice - you are going about it the wrong way.ĭrawing a waveform and using that as the basis for your simulation stimulus works ok for some very basic tests.
#MODELSIM FORCE PDF#
I don't recall the exact procedure, I just followed the documentation - from the Modelsim GUI click on Help -> PDF Documentation, User's Manual. I was playing with the waveform editor in Modelsim 10.0c (Quartus 11.1sp1) last week.
#MODELSIM FORCE WINDOWS 7#
I'm using Quartus II V12.1 with Modelsim-Altera Starter edition V10.1b on a Windows 7 machine. I feel like i'm missing something fundamental or i haven't setup my Modelsim quite right.
As i can't find a option to open the waveform wizard and it doesn't allow me to modify the clock waveform, as shown in this screen shot i've taken of what it shows in the Wave window. The object appears in the Wave window but the only waveform i'm able to produce is a clock. I assumed that they might have changed the 'Create Wave' option to 'Add Wave' but when i click this the 'Create Waveform Wizard' doesn't appear either. When i right click on an object, the 'Create Wave' option doesn't appear, as shown in the screenshot i've taken of what i see. I'm following the tutorial 'Introduction to Simulation of VHDL Designs Using ModelSim Graphical Waveform Editor' by Altera found at - Įverything seems to work okay up to the point of creating the waveform on the Wave window. I'm attempting to use Modelsim for the first time.
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