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Altera_Forum's avatar
Altera_Forum
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16 years ago

Reprogramming protection?

I want to reprogram a MAX II CPLD (EPM1270T144C5N) with USB-Blaster download cable. Programmer can’t access JTAG chain despite I have verified that voltages on board and on 10-pin male header are right. I doubt that CPLD is protected against reprogramming because I see the blue light on USB-Blaster for few seconds. May be? Are there other software settings to configure? For example, configuring a JTAG Server in Hardware Setup is necessary? What can I do yet?

Thanks, ;)

Fabio

1 Reply

  • Altera_Forum's avatar
    Altera_Forum
    Icon for Honored Contributor rankHonored Contributor
    16 years ago

    "Can't access JTAG chain" means that the device isn't accessed at all. It#s usually due to a wiring error. MAX II has a readout protection (security bit) and no overwrite protection. If it had, it would no affect the ability to identify the device on a JTAG chain.

    Some older CPLD devives had on option to disable the JTAG interface after programming, but MAX II hasn't. Generally, you should follow the JTAG troubleshooting tips in the MAX II devive manual.