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Altera_Forum's avatar
Altera_Forum
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16 years ago

scaler problem

Hi, I have another problem about scaler, it's right that adding a control port to scaler makes the input resolution changable, but some resolution doesn't work.

My data path is listed below.

Clocked Video Input(CVI) -> Scaler(SCL) -> Frame Buffer(FB) -> Mixer(with Test Pattern) -> Clocked Video Output(CVO)

The settings of SCL please see the attachments

During run-time, I changed the output size of scaler to 1024x768, and I started to change the input resolution, all the resolutions above and include 800x600 worked pretty fine. But when I set the resolution below 800x600, like 720x480 or 640x480, it flickered badly.

Any reply is appreciated!

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  • Altera_Forum's avatar
    Altera_Forum
    Icon for Honored Contributor rankHonored Contributor
    15 years ago

    Hi All,

    Just wanted to provide an update. It appears as if the logical function of the video path is good, e.g. I can trace a pixel through the system and have it come out of the CVO when doing the 800x600 -> 1600x1200 scaling. The external device that translates the CVO (FPGA Output) to a 1600x1200 capable monitor seems to be seeing something different in this particular scaling mode, although at this time I cannot determine exactly what that is signal integrity wise. I suspect this may be because of FPGA timing problems, or, an output drive problem.

    Thanks,

    Mike