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LMH1983: TOF1 Pulse width

user6429312
Prodigy 100 points
Part Number: LMH1983
Other Parts Discussed in Thread: LMH1980,

Hi Team,

Could you advise about TOF1 Pulse width.

Our system use LMH1980 + LMH1983 for genlock.

In according to LMH1983 Document, TOF1 Pulse width is equart to 1 x H period.

quote:

But, in our experimentation, TOF1 Pulse width is measured 5 x H period.

LMH1983 register setting is below.
Do I need to change any settings?

Thanks

Best regards,

Sohhei

  • 0
    TI__Guru** 107470 points

    Hi Okada-san,

    I need to find the right person to support this question, please allow a few days for this. Thank you.

  • 0 in reply to Noel Fung
    TI__Mastermind 28550 points

    Hello Okada-san,

    I apologize for the delay.  I wanted to see if this issue was still present?

    I note the text says, if the TOF is aligned, will be a pulse with a width of 1 x H period....

    • It seems the TOF is aligned with HIN, is that do you have the understanding that TOF is aligned (and therefore should be only 1 pulse?)

    You are testing with an NTSC signal?

    73,
    Timothy

  • 0 in reply to Timothy T
    Prodigy 100 points

    Noel-san, Timothy-san, 

    Thank you for reply.

    >  I wanted to see if this issue was still present?
    Yes,,, I'd like to clarify the reason.

    > do you have the understanding that TOF is aligned
    Yes, I think TOF is aligned, because LMH1983 register ALIGN STATUS(0x0001[6]) is H.

    > You are testing with an NTSC signal?
    LMH1983 register INPUT FORMAT(0x0020) is 0x15. ->1080I29.97
    Does that answer your question?

    BR,
    Sohhei

  • 0 in reply to user6429312
    TI__Guru** 107470 points

    Hi Okada-san,

    Timothy and I do not familiar with this part, we will need to setup an EVM to verify. We estimated that we will have the EVM and test equipment ready by end of May. 

    BTW, would you educate us what is the impact to the system if TOF is longer than 1x H?