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Altera_Forum
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13 years ago

Is CONF_DONE read by the FPGA?

Hi All,

I'm debugging a board with a Cyclone IV device where the CONF_DONE pin was inadvertently left floating. The FPGA configures fine over JTAG but when configuring from EPCS it reads the whole configuration from the EPCS and then toggles nStatus and starts over. Once upon a time I think there was an option to get the FPGA to ignore CONF_DONE but it doesn't seem to be there anymore in 12.1SP1. I've checked all the usual stuff (MSEL pins set correctly, etc) and the only suspicious thing I can find is the floating CONF_DONE pin. Does anyone know if this will scupper configuration from EPCS?

Thanks,

Mark.

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

    --- Quote Start ---

    Once upon a time I think there was an option to get the FPGA to ignore CONF_DONE but it doesn't seem to be there anymore in 12.1SP1.

    --- Quote End ---

    Its still there.

    File->Convert Programming File, Click on the Advanced options. There's a check-button there that says "Disable AS mode CONF_DONE error check".

    Though I suspect that applies to AS programming with a JTAG cable, rather than with an EPCS device, since the EPCS device cannot check CONF_DONE ... but then again, perhaps the FPGA does an internal check of CONF_DONE.

    Report back on whether it made a difference.

    Cheers,

    Dave