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Asaf_Bloch's avatar
Asaf_Bloch
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3 months ago
Solved

Cold Temperature Issue

Hallo,

We used the Agilex5 device in AS configuration connect to external QSPI Flash.

We apply Smart VID interface at the device demands. 

When we perform Cold power up at -40C the device is not configured, It seemed the device is not  output from the POR, No traffic on the PMBus.   

Power sequence and voltage ramp time and levels are OK.

Please advise

Thanks

Asaf

 

 

Configuration
Programmable Logic Device
  • Farabi_Altera's avatar
    Farabi_Altera
    2 months ago

    Hi Asaf, 

     

    Good to hear that you solved the issue. Yes, all the configuration signals are sensitive can't let the voltage drop even few microseconds. 

28 Replies

  • Asaf_Bloch's avatar
    Asaf_Bloch
    Icon for New Contributor rankNew Contributor
    2 months ago

    Hello Farabi,

    The 3.3V ramping because there are pull-up resistors connected to the system 3.3V, it is low voltage level,

    Anyway I moved it and it did not change the cold issue.

     I notice the MSEL and nconfige signals are pull up and down during Vccio_SDM ramping, is it normal behavior? See attached

    Thanks 

    Asaf

    • Farabi_Altera's avatar
      Farabi_Altera
      Icon for Regular Contributor rankRegular Contributor
      2 months ago

      HI Asaf, 

       

      No that is not normal. MSEL is a fixed connection either HIGH or LOW only. It should not toggle during configuration. 

      Please connect MSEL pin directly to VCC for HIGH, and directly to GND for LOW setup. Dont control the MSEL. 

       

      regards,

      Farabi

      • Asaf_Bloch's avatar
        Asaf_Bloch
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        2 months ago

        Thanks Farabi,

        The issue is after configuration I see the MSE2 is rising to 1.8V, seemed it by the FPAG, is it normal?

        Can it harm the pin?

        Thanks

        Asaf

         

  • dpcsu_e's avatar
    dpcsu_e
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    3 months ago

    Hi,
    just a short question (do not want to deter this thread): how did you detect it is not out of POR?

    (maybe relevant maybe not) On 2 out of 50 Agilex3 devices we have met with similar issue and resulted that over JTAG idcode was read as F36FF0DD instead of 4365B0DD. Is it equivalent to this same issue that SDM ROM code is not coming out of POR? do you observe similar behavior?

    How does your power topology looks like?

    We have 1.8V and 3.3V HVIO and if 3.3V HVIO's VCCIO do not get some minor accidental backfeed which raises it to 0.6V then FPGA stays in POR. 
    Voltage rail sequence is 0.75V -> 1.8V -> 1.2V -> 3.3V.
    Is it ok to bring up 1.8V SDM and 1.8V VCCIO at the same time or should we bring up the 1.8V+3.3V VCCIO after 1.2V?

    Thanks,
    Peter

    • Asaf_Bloch's avatar
      Asaf_Bloch
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      3 months ago

      Hi dpcsu,

      Thanks for your reply

      Our voltage rail sequence is VID, 08V -> 1.8V -> 1.2V, 3.3 VCCIO

      We detect the POR issue because we don't see any signal transitions after power up (nStatus, PMBus), JTAG detect the device.

      How did you read the SDM ROM?

        Any way we repeat the test with other PCB and it pass successfully, so we examine if it specific PCB issue.

      regards

      Asaf 

      • Farabi_Altera's avatar
        Farabi_Altera
        Icon for Regular Contributor rankRegular Contributor
        3 months ago

        Hello Asaf, Peter, 

         

        Do you have update? 

         

        regards,
        Farabi

  • Farabi_Altera's avatar
    Farabi_Altera
    Icon for Regular Contributor rankRegular Contributor
    3 months ago

    Hello, 

     

    Can you share below information:

    1- QSPI flash part number

    2- VR(Voltage regulator) part number

    3- Agilex5 part number

     

    regards,

    Farabi

    • Asaf_Bloch's avatar
      Asaf_Bloch
      Icon for New Contributor rankNew Contributor
      3 months ago

      Hello Farabi,

      1 - QSPI Flash -  MT25QU256ABA8E12-1SIT by Micron

      2 - VR - LT7184SRV#TRPBF by Analog Device

      3 - Agilex5 - A5EC043AB23AI2E

      Thanks

      Asaf

       

      • Farabi_Altera's avatar
        Farabi_Altera
        Icon for Regular Contributor rankRegular Contributor
        3 months ago

        Hello Asaf, 

         

        If the device is not output from POR, do you have the oscilloscope capture the power rails ramping up? 

        Any abnormal voltage ramp up during power up? Especially all the power rails monitored by POR circuitry. 

         

        regards,

        Farabi