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Altera_Forum's avatar
Altera_Forum
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14 years ago

JTAG error only when programming

Hello,

I have a custom board with a MAXII CPLD (EPM2210F256), with the JTAG port built per the Handbook. With Quartus-II v. 9.1 and a ByteblasterMV cable I can ID the device, erase it, and blank-check it with no problem.

Only when I try to program it do I get the error: "can't access JTAG chain." I put an oscilloscope on the (4) JTAG signals and the power supply- all look very clean.

The data book says "Failures during in-system programming may occasionally be related to the Quartus II software" and says to look on the web site for details. I haven't found any there.

Can anyone shed any light on this or suggest other ideas to check?

Much appreciated...

3 Replies

  • Altera_Forum's avatar
    Altera_Forum
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    14 years ago

    --- Quote Start ---

    I put an oscilloscope on the (4) JTAG signals and the power supply- all look very clean.

    --- Quote End ---

    What bandwidth is your scope? A low bandwidth ~50MHz scope might not show ringing and steps in the TCK signal due to transmission line reflections.

    --- Quote Start ---

    Can anyone shed any light on this or suggest other ideas to check?

    --- Quote End ---

    Try another ByteBlaster, or better yet, try a USB-Blaster. If you don't have one, Terasic sells them for $50. They work well.

    Cheers,

    Dave
  • Altera_Forum's avatar
    Altera_Forum
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    14 years ago

    Dave, thanks for your reply. My scope is 200MHz BW, 1Gsa/sec. If there are any glitches they are <10nsec wide and die out very fast.

    Probably I will try the Terasic programmer (note Atlera lists their USB-Blaster for $300!). Also in proces of downloading the latest Quartus SW, so we'll see...

    Thanks again.
  • Altera_Forum's avatar
    Altera_Forum
    Icon for Honored Contributor rankHonored Contributor
    14 years ago

    --- Quote Start ---

    My scope is 200MHz BW, 1Gsa/sec. If there are any glitches they are <10nsec wide and die out very fast.

    --- Quote End ---

    Ok, the scope sounds good enough. The fact that you do not see any glitches is a good sign.

    --- Quote Start ---

    Probably I will try the Terasic programmer (note Atlera lists their USB-Blaster for $300!). Also in proces of downloading the latest Quartus SW, so we'll see...

    --- Quote End ---

    Yeah, the Altera versions are way too pricey. The Terasic versions work great!

    Cheers,

    Dave