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  • TI Thinks Resolved

DLPC3430: DLPC3430 DSI Locks up

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Replies: 4

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Part Number: DLPC3430

Hello,

I have a design which uses the DLPC3430 and it receives pixel data over the DSI interface. Under normal operation (both host DSI processor and DLP are operating) the output is fine.

The issue occurs when the host processor DSI interface is disabled and then re-enabled. In most instances, the DLP DSI interface is not affected and the output is updated correctly. But occasionally the DLP DSI interface seems to lock up and not update the output. When this occurs, the video output can be changed to test mode and test mode images can be output correctly, so the device is not completely locked up.

In order to get the DSI interface working again the DLP3430 needs to have the PROG_ON signal cycled to re-initialize the device.

Are there any I2C commands that can be used to 1) reset the DSI port and 2) monitor the status of the DSI port?

Thanks,

Chuck

  • Chuck,

    Welcome to the E2E forums, and thanks for your interest in our DLP technology.

    I'll look into providing some information about available DSI commands. In the meantime, have you noticed any consistent pattern in your fail cases? For instance, does displaying particular content cause the system to fail more frequently when toggling use of your DSI input?

    Best Regards,
    Philippe Dollo
  • In reply to Philippe Dollo:

    Hey Philippe,

    Thanks for the reply. The particular content does not seem to affect the failure rate. I'll give a little more context to our setup.

    We have a system where an FPGA is the host processor and connects to multiple DLP chipsets through DSI (each DLP has its own MIPI DSI IP core inside the FPGA). Most boards operate correctly and there is no issue seen when the DSI connection disabled and then re-enabled.

    There are some boards however, where some DLPs experience a DSI lock up under the same situation. The only pattern that is observed is that when a particular DLP experiences this issue, it will always experience this issue.

    The DSI connection on the problematic DLPs can be correctly initialized and can operate for extended periods of time without issue. A problem is only seen when the DSI connection is disabled.

    But the current DLPC3430 programmers guide does not provide any commands that could 1) report any status that could hint at the problem or 2) provide a means to reset just the DSI portion of the DLP.

    Currently the only workaround we have found is to cycle PROJ_ON and reinitialize the DLP every time the DSI is disabled.

    Any insights or information you can provide on the DSI commands would be greatly appreciated.

    Just let me know if there some additional information you think would be helpful.

    Chuck
  • In reply to Chuck Rumbolt:

    Hello Chuck,

    Could you try re-sending the operating mode select command (0x36 05 00) to set to external video? If that doesn't work you could try setting to test pattern then back to external video (0x36 05 01 followed by 0x36 05 00). 

    I'd also recommend to check your DSI setup against the below debugging guide. If any of your DSI parameters are out of spec (or perhaps close to the edge of our specification), it's possible there may be some issues. 

    Thanks,

    Kyle

    1452.DSI Setup and Debugging Guide v0.2.pdf

  • In reply to Kyle Rakos:

    Hello Chuck,

    I hope that worked. If you have any additional questions please let me know.

    Thanks,
    Kyle

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