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VHDL and Report Usage Report

I am having some problems with the VHDL code I wrote (see my other question for details if you are interested: VHDL integer'image Returns "0" ). I need to somehow see what happens to my variables. Everything I read seems to indicate that I should use the report statement to see some kind of output, but nothing I read tells me where . I would see this conclusion.

So my question is:

I write VHDL code and program the Altera DE2 FPGA board ... Can I use the report statement to get some result, and if so, how? I am currently using Altera Quartus II software. I tried installing ModelSim, but the student release does not seem to work on Windows 7 (I can't even install the installer so that it displays ... starting the installation just left the process freezing).

Thanks!

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3 answers

The report operator outputs its output to the console of your simulator. If you work with Altera, you probably want to get the version of ModelSim that they send.

a := 5; report "The value of 'a' is " & integer'image(a);

People also use wave traces to debug their code. But for this you also need your simulator.

You need to find a way to install ModelSim on your Windows 7.

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Both Philip and Martin provided excellent answers to your question, but I want to emphasize an important aspect of what VHDL is. VHDL is a tool that serves two completely different purposes.

On the one hand, it is a behavioral modeling language for describing parallel systems. Your model is compiled into an executable file and runs on your computer. This is what we call a simulator. This allows you to test the model during various execution states and simplifies debugging your design before proceeding to the next step: Implementation.

VHDL is also used as a metalanguage to describe the hardware architecture known as RTL. This description is translated into a list of primitives supported by your architecture (synthesis), and then placed and routed to a physical device.

It is important to understand the difference between these two uses in order to make full use of the language. Happy coding!

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REPORT is displayed on the simulator console.

Modelsim in GUI mode has a console window. If console mode, that's all, just a console anyway!

GHDL is also a console mode, so it will be displayed in the terminal / CMD window when starting the simulation.

What REPORT cannot do is print messages from synthesized code.

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