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TVP5150 interrupt questions

Kailyn Chen
Genius 9560 points
Other Parts Discussed in Thread: TVP5150

Dears;

 

    I  have a customer who use DM642 and TVP5150 do image capture. In the DSP / BIOS, through an external interrupt to trigger the acquisition thread. His flow is that once external interrupt is coming, start image capture. Intermediate process is that first TVP5150 FIFO data will be sent to EDMA, and then go deal with the data memory. But now his situation is that TVP5150 is always working and when the interrupt signal is coming,he can not guarantee that the image is suspended .  So my question is whether the  PowerDown register control mode control bit could get to his purpose, what if the PDN pin , is it in low status at the same time? Or do you have any other advise?

Best regards
Kailyn
  • 0
    TI__Genius 16810 points

    Kailyn,

    We need clarification on this issue and question.

    - Is the TVP5150 being used to generate the interrupt?  If yes, which interrupt source is being used (programmed) in the TVP5150?

    - Does "TVP5150 FIFO data" refer to YC data frame buffer in the DM642 or TVP5150 VBI FIFO data?

    - Are they  basically trying to determine when the TVP5150 is locked to a valid input signal, so they can start or reset image capture?

     

    BR,

    Larry

  • 0 in reply to Larry Taylor
    TI__Genius 9560 points

    Dear Larry,

       Thank you for your reply.

      Yes, the customer is  trying to determine when the TVP5150 is locked to a valid input signal, so they can start or reset image capture. Do we need give a signal to active the PDN pin ?

    Best regards

    Kailyn

  • 0 in reply to Kailyn Chen
    TI__Genius 9560 points

    Dear Larry;

     I have confirmed to the customer about the below questions.

    - Is the TVP5150 being used to generate the interrupt?  If yes, which interrupt source is being used (programmed) in the TVP5150?

    A: The customer wanted to use DSP to generate the interrupt.

    - Does "TVP5150 FIFO data" refer to YC data frame buffer in the DM642 or TVP5150 VBI FIFO data?

    A: TVP5150 FIFO data .

    - Are they  basically trying to determine when the TVP5150 is locked to a valid input signal, so they can start or reset image capture?

    A:Yes.The customer is trying to determine when the TVP5150 is locked to a valid input signal, so they can start or reset image capture. Do we need give a signal to active the PDN pin ?

  • 0 in reply to Kailyn Chen
    TI__Genius 16810 points

    Kailyn,

    When the TVP5150 is in the powered down state (PDN=low) the TVP analog front end and ADCs are powered down.  In this state, the TVP5150 cannot acquire lock, update status registers, slice and process VBI data, or generate an interrupt request.  PDN must be inactive (high) to use these features.   To detect signal present when the TVP5150 is powered down, additional external circtuiry must be used to sense signal present.

    Regards,

    Larry

  • 0 in reply to Larry Taylor
    TI__Genius 9560 points

    Hi, Larry,

      Thank you very much for your kindly reply. I'd like to know how we get to power-down mode? because my customer has tried  setting it into power down using the

    "Operation Mode Controls Register" 0X02h bit[0], but the TVP5150 is still working, so I wonder if we need pull down PDN at the same time?

     

    Thank you in advance

    Kailyn

  • 0 in reply to Kailyn Chen
    TI__Genius 16810 points

    Kailyn,

    The Power-down mode control in I2C register 02h powers down the ADCs but leaves internal clocking and the processor enabled to retain I2C functionality.  To achieve the lowest power state, the PDN pin must be used.

    When then PDN pin is active low, I2C communication will not function.  When the PDN pin is deactivated (taken back high), some delay will be required to allow the crystal/clock circuitry to stabilize prior to I2C communication.   A delay of 20ms should be more than adequate.

    Regards,

    Larry