Forum Discussion

PSriv8's avatar
PSriv8
Icon for New Contributor rankNew Contributor
5 years ago

May I use WYSIWYG for hardware or is it applicable only for synthesis?

May I use WYSIWYG for hardware or is it applicable only for synthesis?

I am trying to calculate the delay of a barrel shifter using the DE-115 FPGA board and digital oscilloscope. The shifter inputs are assigned to the FPGA switches (SW) and shifter outputs are assigned to the FPGA LEDs (LEDR). I have used a digital oscilloscope to tap the input and output signals simultaneously; therefore, the delay required by output after the change in input can be measured. The waveform suggests that the delay between input and output is always the same irrespective of the number of stages required by the shifter. This might happen due to the optimization of the design using logic elements LEs. Can I use the WYSIWYG feature for hardware testing so that the logic cells un-map the design into logic gates?

Because Intel® Quartus® Prime Standard Edition User Guide mentioned the following:

"However, WYSIWYG primitive resynthesis can be done only when you use third-party synthesis tools."

Therefore, I am not sure whether the WYSIWYG feature can be used for hardware testing or not. Also, is it available in the free version of Quartus?

6 Replies

  • sstrell's avatar
    sstrell
    Icon for Super Contributor rankSuper Contributor

    It is available in Lite and Standard editions, but like you say, it is only for when the results of a 3rd-party synthesis tool are brought into Quartus for place and route.

    You could make use of timing reports in the Timing Analyzer to see the calculated delay from an input to an output.

    #iwork4intel

    • PSriv8's avatar
      PSriv8
      Icon for New Contributor rankNew Contributor
      Thank you for your reply. I still have few questions in mind, it might be very basic as I m still learning:
      1. I didn't quite understand the meaning of using a 3rd party synthesis tool, coz as per my knowledge we have to use a third-party tool for synthesis (from cadence or synopsis etc) in order to calculate power, area and delay of a circuit. Does quartus have a synthesis tool for calculating the parameters like other synthesis tools can do?

      2. I have designed a block diagram file (.bdf) with three stages of 2x1 muxes connected in series i.e. Output of stage 1 connected to input of stage 2 and output of stage 2 is connected to input of stage 3. The inputs are connected to switched of FPGA board and outputs are connected to LEDs. Now I connect the input switches and LEDs to a Digital oscilloscope and capture the waveform. The output changes after a delay of almost 12ns after it detects change in input.

      I was expecting that taking output from various stages would require different time, for example: if tapping input from stage 1 and output from stage 1 requires time T, then tapping input from stage 1 and output from stage 2 should be 2T to and tapping input from stage 1 and output from stage 3 should be 3T. However, I am getting a delay of 12ns everytime irrespective of no of stages used. That is why I wanted to use the WYSIWYG feature. Could you please suggest.
      • sstrell's avatar
        sstrell
        Icon for Super Contributor rankSuper Contributor

        1) All the features you mentioned are built into Quartus. Using a 3rd party synthesis tool is optional, and usually dictated by the company you work for I have found. Built-in synthesis is usually more than sufficient for most designers and it's one less tool you have to learn/use/manage.

        2) As mentioned, design optimization is probably causing this. If you need specific delays for a design, you need to incorporate them into SDC timing constraints, such as set_max_delay and set_min_delay. If you're not familiar with timing constraints and analysis, start here with this training:

        https://www.intel.com/content/www/us/en/programmable/support/training/course/odsw1115.html

        #iwork4intel