[ADV7480] About register settings when a resolution of HDMI input is changed during the operation.

Hello.

I have a question about register settings for ADV7480.

When a resolution of HDMI input is changed during the operation, is "SW reset" required before the register settings for ADV7480?
or
Can we set only the registers which value is changed by the resolutions in the script without "SW reset"?

For example, when a resolution changes 1080p60 to 720p60 during the operation(keeping HPD = high),
Do we have to set "E0 FF FF ; SW reset" and then all of the register settings in the script have to be set?
or
Can we set only different registers between 1080p60 and 720p60 without SW reset?

Thank you!
Best regards.
Tamu

  • Hi,

     Can we set only the registers which value is changed by the resolutions in the script without "SW reset"?
       Software reset is not needed when resolution change and also no need to write any register for resolution change.
       Below 2 possible ways are used to readback when new format has detected.
        1) The VID code in the AVI infoframe.
        2) HDMI Synchronization parameters read back registers.
    The part doesn't do anything with this information-- you have to read it and set it up for what output you want.  It does not change the format in any case.  What comes in is what goes out.  If the format changes you will need to detect that and set up your system for the new format.
    Note: The ADV748x is also capable of automatically detecting the incoming video standard with respect to the following.
        • Color subcarrier frequency
        • Field rate
        • Line rate

    For example, when a resolution changes 1080p60 to 720p60 during the operation(keeping HPD = high),
    Do we have to set "E0 FF FF ; SW reset" and then all of the register settings in the script have to be set?
      No, Generally software reset can be used after power up.

    Thanks,

    Poornima