VHDL test bench in Quartus

May 28, 2004 7 Replies

Is it possible to write a test bench using VHDL in Quartus? When I tried I got an error message telling me that wait construct is not supported. Is that true or am I making some mistake? Is there any way, may be using tcl, I can simulate a VHDL like test bench? Testbench using waveforms just does not work for me. Thanks.



Pratip Mukherjee pratipm.remove snipped-for-privacy@hotmail.com


No. Use modelsim or sonata.

-- Mike Treseler

My guess, is that Quartus only supports synthesizeable VHDL and wait is not synthesizeable. If I not mistake, you have only the waveform program to create testbenches, and so I use Modelsim for my simulations of Altera-targeted designs.

Salman

Pratip Mukherjee wrote:

There is something missing in this discussion. If you are talking about testbenches, then Quartus can't help you since testbenches are used in simulations and Quartus is not a VHDL simulator.

I agree that using waveforms to simulate FPGA designs is not desirable. That is why I write my code to run on either Altera or Xilinx devices and use the Xilinx Modelsim simulator to test my design. I then fit the same design to the Altera devices.

salman sheikh wrote:

Rick "rickman" Collins rick.collins@XYarius.com Ignore the reply address. To email me use the above address with the XY removed. Arius - A Signal Processing Solutions Company Specializing in DSP and FPGA design URL http://www.arius.com 4 King Ave 301-682-7772 Voice Frederick, MD 21701-3110 301-682-7666 FAX

I'd love to hear why.

Regards,

-rajeev-

A test bench is not just a static waveform generator, it can be an interactive environment simulator. I can write code to model an external memory or MCU bus cycles or any other interface. As my design progresses it can take a lot less work to keep a testbench up to date than it would to redo waveforms.

Maybe it is just a personal preference, but I find a VHDL testbench to be the best way of testing a design I have found.

Rick "rickman" Collins rick.collins@XYarius.com Ignore the reply address. To email me use the above address with the XY removed. Arius - A Signal Processing Solutions Company Specializing in DSP and FPGA design URL http://www.arius.com 4 King Ave 301-682-7772 Voice Frederick, MD 21701-3110 301-682-7666 FAX

rickman wrote in news: snipped-for-privacy@yahoo.com:

If the design has some Altera specific MegaFunction, then don't you have to have another version of the same file using generic VHDL construct? Can Xilinx/ModelSim be made to understand Altera specific constructs? I am talking about the free version of ModelSim which comes with WebPack. Thanks.

What MegaFunction are you thinking that I would use? I have found that the block rams can be described in generic VHDL. I expect that any other feature would be device specific. One that I will likely end up using is the cascade chain in the Altera parts, they are useful in wide input muxes. I believe I asked about how to get these from generic code and did not get a good answer from Altera. So I may have to do as you are saying and use a conditional depending on the target. I started to do that with the memory before I found that both environments worked well with generic code. Its not hard to do.

Rick "rickman" Collins rick.collins@XYarius.com Ignore the reply address. To email me use the above address with the XY removed. Arius - A Signal Processing Solutions Company Specializing in DSP and FPGA design URL http://www.arius.com 4 King Ave 301-682-7772 Voice Frederick, MD 21701-3110 301-682-7666 FAX

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