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Altera_Forum's avatar
Altera_Forum
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11 years ago

MAX7000 programming question

Hello, please advise - I am starting using MAX7000S device - PLCC44. It has 8 power pins, 4 JTAG pins and 32 user i/o pins. I needed more than 32 pins for i/o, and disabled "JTAG BST support", giving me 36 pins to use.

I read through programming guide, but it does not elaborate how to handle situations when I use these JTAG pins as i/o.

Please explain my programming options (I have byteblaster2 and want to reuse it for this project) and point me to respective documentation discussing the issue. Thank you.

4 Replies

  • Altera_Forum's avatar
    Altera_Forum
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    11 years ago

    If JTAG is disabled, the device can be only reprogrammed by external programming hardware like the the Altera "Master Programming Unit" or supported third party programmers. So disabling JTAG should be considered wisely before.

  • Altera_Forum's avatar
    Altera_Forum
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    11 years ago

    Thank you very much! I hope you can also give me answers to the following two questions:

    1. is there any hobbyist diy/professional circuit diagram for such programmer? I do have programmer which does not support Altera devices (at all) and as will need to program these, ready to build custom programming device instead of buying one;

    2. how many decoupling capacitors are recommended for the MAX7000 devices (it has 4 pairs of power rails, relatively close to each other).
  • Altera_Forum's avatar
    Altera_Forum
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    11 years ago

    The MAX7000 datasheets mentions some industry standard programmers (e.g. DATA-IO) supporting it. I presume there exists a specification of MAX7000 programming algorithm, but I wasn't yet aware of it or any DIY programmer designs. Today, MAX7000 and MAX3000 are legacy devices and will be hardly supported by new tool developments.

    Requirement of bypassing depends on the involved signal speed and amount of simultaneous switching outputs, I believe. As a standard measure, I would place one bypass capacitor at each VDD pin. I have however an old design with a socketed MAX7032 in PLCC package on a two layer board that works well with a single bypass capacitor.
  • Altera_Forum's avatar
    Altera_Forum
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    11 years ago

    --- Quote Start ---

    The MAX7000 datasheets mentions some industry standard programmers (e.g. DATA-IO) supporting it.

    --- Quote End ---

    I saw some pictures. They are monsters :) Buying those is just not cost effective. I would better use discrete logic then...

    --- Quote Start ---

    I presume there exists a specification of MAX7000 programming algorithm,

    --- Quote End ---

    I also thought this way, but found no information about it. MAX7000 datasheet does not have any trace to high voltage information. That seem to be a big secret...

    BTW, I created support ticket to Altera two days ago and... silence.

    --- Quote Start ---

    but I wasn't yet aware of it or any DIY programmer designs.

    --- Quote End ---

    That is not a problem :)

    --- Quote Start ---

    Today, MAX7000 and MAX3000 are legacy devices and will be hardly supported by new tool developments.

    --- Quote End ---

    Agree. The selection was made basing on +5v supply/TTL operating level, and availability on the market. To my knowledge, all later devices are 3v3 max.

    --- Quote Start ---

    Requirement of bypassing depends on the involved signal speed and amount of simultaneous switching outputs, I believe. As a standard measure, I would place one bypass capacitor at each VDD pin. I have however an old design with a socketed MAX7032 in PLCC package on a two layer board that works well with a single bypass capacitor.

    --- Quote End ---

    Thank you. I had 4 as you advised, but board space became scarce and I had to remove all four while routing adjacent devices. I will see if I still can keep all 4, or will leave two.