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Altera_Forum's avatar
Altera_Forum
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15 years ago

Another Cyclone III problem

Hi,

I've got a problem with configuring CycloneIII(EP3C120F780I7N) in AS mode on my custom board. Also when I

try to programm my EPCS64, Quartus programmer says that Device ID can't be read. Another thing is that after

I turn the power on I see strange AS signals from FPGA (Bank 1 is powered with 2.5V but nCSO=2.5V,

DCLK=2.5V, ASDO=2V, DATA0=2V). So it means that FPGA doesn't even try to configure itself.

Programming EPCS with .jic file also fails.

But if I try to configure FPGA via JTAG, everything works well.

I've already tried changing EPCS and even FPGA and it didn't help.

Any helpful suggestions?

2 Replies

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

    Maybe the capacitance on your AS lines is too big. You should check values of your capacitors

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

    That's it! The problem solved))

    There were 87nF capacitors instead of 10pF. Company where my custom board was made failed.

    Thanx))