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Armando1989's avatar
Armando1989
Icon for Occasional Contributor rankOccasional Contributor
1 year ago
Solved

EPM7128LC84-7N CANNOT BE ACCESSED

Hi Guys!

Have kit board that have been working with EPM7128LC84-15 chips, including some purchased from ebay.

Recently acquired some higher speed grade EPM7128LC84-7N also from ebay. However when inserted into board, J-TAG cannot read device.

 

Have selected -7 grade, i suppose -7"N" should be same?. Dos that "n" make any difference?. Or is definetly any issue with those chips?

Thanks in advance!

Fpga Devkit
  • _AK6DN_'s avatar
    _AK6DN_
    1 year ago

    You first need to be careful with your nomenclature.

    EPM7128LC... devices are NOT JTAG programmable devices. They must be programmed on a 3rd party parallel programmer.

    EPM7128SLC... (note the 'S') are JTAG programmable devices, but they can be programmed to disable the JTAG pins and use as I/O pins.

    I am assuming your use of the non-S part number was just a typo on your part.

    But the parts you sourced from eBay who actually knows if they are good, bad, or counterfeit?
    Maybe your seller knows, or maybe not.
    Almost invariably parts this old are pulls from equipment.

    They could be good parts but were programmed to disable the JTAG interface in their past application, to mimic non-JTAG parts.
    If so, you need a 3rd party programmer to erase the programming and reenable the JTAG interface.

    And the -N suffix just means it is in a Pb-free package. The internal part is the same, -N or not.

6 Replies

  • _AK6DN_'s avatar
    _AK6DN_
    Icon for Frequent Contributor rankFrequent Contributor
    1 year ago

    You first need to be careful with your nomenclature.

    EPM7128LC... devices are NOT JTAG programmable devices. They must be programmed on a 3rd party parallel programmer.

    EPM7128SLC... (note the 'S') are JTAG programmable devices, but they can be programmed to disable the JTAG pins and use as I/O pins.

    I am assuming your use of the non-S part number was just a typo on your part.

    But the parts you sourced from eBay who actually knows if they are good, bad, or counterfeit?
    Maybe your seller knows, or maybe not.
    Almost invariably parts this old are pulls from equipment.

    They could be good parts but were programmed to disable the JTAG interface in their past application, to mimic non-JTAG parts.
    If so, you need a 3rd party programmer to erase the programming and reenable the JTAG interface.

    And the -N suffix just means it is in a Pb-free package. The internal part is the same, -N or not.

    • Armando1989's avatar
      Armando1989
      Icon for Occasional Contributor rankOccasional Contributor
      1 year ago

      Hi AK6DN! thanks for your answer.

      It was just typo, indeed, they all are EPM7128SLC. My best bet is those guys have screwed the jtag programing capability... When i power on those chips some light blink then stops, thus i guess there is already a program inside, maybe protected already from 3 party manufacturer project... Maybe they just have fetch those chips as they were on some board and announce on ebay....

      Ill ask for a refund i think...

      BR

      • Armando1989's avatar
        Armando1989
        Icon for Occasional Contributor rankOccasional Contributor
        1 year ago
        Hi Farabi
        Chips had been returned and ive been refund. My best bet is as _AK6DN_, cplds cannibalized from scrap pcbs that have been previously jtag disabled by developer.
        Thanks in advance
  • Farabi's avatar
    Farabi
    Icon for Regular Contributor rankRegular Contributor
    1 year ago

    Hello,


    The FPGA you bought might be not working or damaged. You can try lower down you JTAG TCK to see if it can program the device or not. Please make sure you use USB Blaster I cable for older devices like MAX7000 FPGAs.


    regards,

    Farabi


    • Armando1989's avatar
      Armando1989
      Icon for Occasional Contributor rankOccasional Contributor
      1 year ago
      Hi Farabi
      Chips had been returned and ive been refund. My best bet is as _AK6DN_, cplds cannibalized from scrap pcbs that have been previously jtag disabled by developer.
      Thanks in advance
  • FakhrulA_altera's avatar
    FakhrulA_altera
    Icon for Regular Contributor rankRegular Contributor
    11 months ago

    I’m glad that your question has been addressed, I now transition this thread to community support. This thread will be transitioned to community support. If you have a new question, feel free to open a new thread to get support from Intel experts. Otherwise, the community users will continue to help you on this thread. Thank you.