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Mircea's avatar
Mircea
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4 years ago

Arria V - LVDS output performance

Hello,

My 5AGXFB7H4F35C4 receives a 125MHz, ideal reference clock.

Using the internal PLL, I want to generate a 500MHz sampling clock for controlling 8 ADC chips.

1. What is the maximum clock frequency coming out of this device in LVDS?

2. What would be the jitter?

3. What setting should I use, and what output pin for best performance?

I also want to send a 2ns wide SYNC pulse on 8 outputs.

4. What would be the skew between the 8 outputs?

5. What is the minimum pulse width for LVDS outputs?

6. What setting should I use, and what pins for best performance?

7. Where can I read these specs?

Please, don't tell me to just read some 10,000-page data sheet.

Thanks,

Mircea

4 Replies

  • EngWei_O_Intel's avatar
    EngWei_O_Intel
    Icon for Frequent Contributor rankFrequent Contributor
    4 years ago

    Hi Mircea

    Can you check if Table 40 of below doc is what you are looking for?

    https://www.intel.com/content/dam/www/programmable/us/en/pdfs/literature/hb/arria-v/av_51002.pdf

    For output pins, depends on clock or IO types, you can refer to below link:

    https://www.intel.com/content/dam/www/programmable/us/en/pdfs/literature/dp/arria-v/pcg-01013.pdf

    And map your device to the pin out file:

    https://www.intel.com/content/www/us/en/programmable/support/literature/lit-dp.html

    For skew handling, you can refer to timing constraint chapter 1.5.4 of https://www.intel.com/content/dam/www/programmable/us/en/pdfs/literature/ug/ug_altlvds.pdf

    Thanks.

    Eng Wei

    • Mircea's avatar
      Mircea
      Icon for New Contributor rankNew Contributor
      4 years ago

      Hi Eng Wei,

      You only answered question 7.

      If you don't know the answers for questions 1 to 6, please ask someone who knows, and get back to me.

      Here are my questions again:

      My 5AGXFB7H4F35C4 receives a 125MHz, ideal reference clock.

      Using the internal PLL, I want to generate a 500MHz sampling clock for controlling 8 ADC chips.

      1. What is the maximum clock frequency coming out of this device in LVDS? It's not through the ALTLVDS.

      2. What would be the jitter?

      3. What setting should I use, and what output pin for best performance? Please, give example of pin number and setting.

      I also want to send a 2ns wide SYNC pulse on 8 outputs.

      4. What would be the skew between the 8 outputs?

      5. What is the minimum pulse width for LVDS outputs?

      6. What setting should I use, and what pins for best performance? Please, give example of pin number and setting.

      Thanks,

      Mircea

      • EngWei_O_Intel's avatar
        EngWei_O_Intel
        Icon for Frequent Contributor rankFrequent Contributor
        4 years ago

        Hi Mircea

        If you aren't using LVDS SERDES IP, then you shall refer to PLL spec (Table 36) in the same document.

        For differential signal input/output pins, you should always pick from DIFFIO_RX* or DIFFIO_TX* from the list, depends on which IO banks you are using. The min pulse width depends on the max freq achievable in your design.

        For clock skew specific question, I would suggest you to file another request and timing expert will be able to assist you.

        Thanks.

        Eng Wei