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MDiDo's avatar
MDiDo
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5 years ago

Problem with Deinterlacer

Hello, I have a problem with the Deinterlacer IP Core. I created a video system with the following input chain:

CVI->CLIPPER->COLOR PLANE SEQUENCER->CHROMA RESAMPLE->DEINTERLACER->MEMORY CONTROLLER->DDR3 MEMORY

After I created a Testbench to simulate my system. I send a CVBS interlaced video sequence on CVI input. Looking the waveforms the first frame begins to flow through the IPs and the Avalon Control Packets are correct. When the frame arrives on Deinterlacer input, the Deinterlacer output Avalon Control Packet is correct, but after the Deinterlacer output "din_ready" goes low, blocking the entire video flow. The Deinterlacer lowers the "din_ready" and doesn't send command to the Memory Controller in order to write the frame into memory. What's my problem?

17 Replies

  • CheepinC_altera's avatar
    CheepinC_altera
    Icon for Regular Contributor rankRegular Contributor
    5 years ago

    Hi,

    As I understand it, you seems to observe the din_ready from the Deinterlacer II de-asserts after feeding into video data in simulation. When din_ready is de-asserted, the IP is unable to receive further data.

    To facilitate further debugging, would you mind to create a simple test design ie with TPG II -> DIL II (+ memory) -> CVO run with Modelsim simulation. YOu may start with small video resolution ie 100x100 to use on-chip memory to further isolate out the memory controller. Once the simple test design is simulating correctly, you may then slowly replace the component to test out. This would be helpful to narrow down to the root cause.

    Please let me know if there is any concern. Thank you.

    Best regards,

    Chee Pin

    • MDiDo's avatar
      MDiDo
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      5 years ago

      Thank you for the response. I followed your advice, but I get the same problem.

  • CheepinC_altera's avatar
    CheepinC_altera
    Icon for Regular Contributor rankRegular Contributor
    5 years ago

    Hi,

    For your information, I have emailed you a simple simulation example design from wiki previously with A10 TPG -> DIL -> CVO, using on-chip memory. You may try with it and then refer to it for your design. This example is created with Q17.0std.

    Thank you.

    • MDiDo's avatar
      MDiDo
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      5 years ago

      I had already seen that example and it works, but in Deinterlacer is selected the algorithm Vertical Bob. If I start with that example and change the algorithm from Vertical Interpolation to Motion Adaptive, inserting the On-Chip memory, the Deinterlacer doens't work and I get the problem described.

      • CheepinC_altera's avatar
        CheepinC_altera
        Icon for Regular Contributor rankRegular Contributor
        5 years ago
        Hi, Sorry if there is any confusion. If I understand it correctly, the simulation example that I emailed to you is A10_tpg_100i_dil_ma_cvo_q170.zip where the DIL is Motion Adaptive mode. Please let me know if I have emailed incorrect file to you. Thank you. Best regards, Chee Pin
  • MDiDo's avatar
    MDiDo
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    5 years ago

    I received your email. The email text is as follows:

    A10 simple simulation example with TPG -> DIL -> CVO in Q17.0

    ref:_00DU0YT3c._5000Pq1DlN:ref

    But I don't see any simulation example. I haven't received the attached file. Could you send me the file again? Thank you.

    • CheepinC_altera's avatar
      CheepinC_altera
      Icon for Regular Contributor rankRegular Contributor
      5 years ago
      Hi, Sorry for the inconvenience. I will attempt to re-send the file again after splitting the file into smaller size in case it was filtered out by server. I will let you know again once it is done. Best regards, Chee Pin
  • CheepinC_altera's avatar
    CheepinC_altera
    Icon for Regular Contributor rankRegular Contributor
    5 years ago

    Hi,

    I have emailed you a new archive which I further compress the zip. Please let me know if it still cannot get through your email.

    Thank you.

    • MDiDo's avatar
      MDiDo
      Icon for New Contributor rankNew Contributor
      5 years ago

      Thank you. I tried your design, but I get always the same problem. I attack the simulation waveforms. As you can see the deinterlacer starts the frame acquisition and sends the control packet with dout_valid (cyan), but after lowes the din_ready (yellow) and stops the frame acquisition. What could be the probem?

      • CheepinC_altera's avatar
        CheepinC_altera
        Icon for Regular Contributor rankRegular Contributor
        5 years ago
        Hi, As I tested running the simulation zip shared to you, the simulation seems to run OK as shown in the following screenshot. The din_ready is asserted to backpressure the TPG and then assert again when it is ready to accept data. Please feel free to let me know if you are not seeing the din_ready assert at later stage of your simulation or if you are observing differently. Thank you. [cid:image007.jpg@01D603A0.DE03CCD0] Best regards, Chee Pin
  • CheepinC_altera's avatar
    CheepinC_altera
    Icon for Regular Contributor rankRegular Contributor
    5 years ago

    Hi,

    Sorry for the inconvenience. I have resent the screenshot thru email attachment. Please let me know if you are still unable to view it.

    thank you.

  • MDiDo's avatar
    MDiDo
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    5 years ago

    I received the screenshot. Your waveforms are ok, but when I run the simulation in your zip I get different waveforms. I don't see the din_ready reassert, it always remains low. I can't understand how it's possible, the test bench file is the same. Mabybe depends on the simulator used. I'm using QuestaSim-64 10.6g.

    • CheepinC_altera's avatar
      CheepinC_altera
      Icon for Regular Contributor rankRegular Contributor
      5 years ago
      Hi, Thank for your update. For your information, I am using Modelsim - Intel FPGA Edition 10.5b at which this design is created and tested with, based on previous information that I got from wiki. You might want to try with Modelsim to see if it works as a workaround. Thank you very much. Best regards, Chee Pin
      • MDiDo's avatar
        MDiDo
        Icon for New Contributor rankNew Contributor
        5 years ago

        If I use Modelsim it correctly works. Anyway I need use QuestaSim in order to create an UVM testbench. I'll try with an other QuestaSim version.

  • MDiDo's avatar
    MDiDo
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    5 years ago

    I resolved my problem. The Deinterlacer with QuestaSim-64 10.6g doesn't work. I installed Questasim-64 10.2c and now correctly works. Thank you so much for your support 🙂

  • CheepinC_altera's avatar
    CheepinC_altera
    Icon for Regular Contributor rankRegular Contributor
    5 years ago

    Hi,

    Glad to hear that you have managed to resolve the issue. Thank you very much.