• State
  • Locked Locked
  • Replies 3 replies
  • Subscribers 46 subscribers
  • Views 649 views
  • Users 0 members are here
Support feedback
Options
Options
Similar topics

This thread has been locked.

If you have a related question, please click the "Ask a related question" button in the top right corner. The newly created question will be automatically linked to this question.

TVP5158 4ch line-interleave demux problem

fan li3
Intellectual 510 points
Other Parts Discussed in Thread: TVP5158

Hi,

Now I use TVP5158 to collect 4ch vedio data, and use FPGA to demux data.

I allocate regs as below,

B0 = 0xA0;
B1 = 0x10;
B2 = 0x25;
B3 = 0xE4;
B4 = 0xE4;
B5 = 0x00;
B6 = 0x1B;
B7 = 0x14;
B8 = 0x40;
B9 = 0x00;

Then OCLK_P is 108M. But after demux on FPGA, the image data is wrong.

So what is the reason? Thanks.

  • 0
    TI__Mastermind 43875 points

    How does your FPGA synchronize and demux?

    Each of the streams will be asynchronous within the synchronous output data stream and you must use the channel ID in the SAV/EAV sequence in order to extract each source stream.

    Note that there WILL be gaps in each stream's data to account for the fact that the source video signals are asynchronous and not phase aligned with each other.

    You cannot simply alternate video lines withing the super frame.

    BR,

    Steve

  • 0 in reply to Steve Clynes
    Intellectual 510 points

    Hi Steve,

    Now we demux data absolutely as datasheet says, use info bits like VDET, BOL, F, V bit in SAV/EAV codes, but the result is still wrong.

    Do you have some reference demux codes using FPGA? Thanks!

  • 0 in reply to fan li3
    TI__Mastermind 43875 points

    Please make sure you have read and fully understand section 3.8.3.2 and in particular Table 3-12 which explains how to extract the channel ID and the line ID.

    We do not have any example FPGA code since the processors we typically connect the TVP5158 to have integrated de-muxing circuits.

    BR,

    Steve