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Altera_Forum's avatar
Altera_Forum
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16 years ago

Stratix II Configuration Problem

Hi, We are having some issues configuring a stratix II FPGA. From quartus we can successfully program the flash from Quartus but the FPGA does not always configure correctly when power is applied....
Altera_Forum's avatar
Altera_Forum
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16 years ago

Well the fact that probing CONF_DONE fixes it is more than odd. We know that CONF_DONE must go high for the device to initialize. Maybe what's happening is noise on the CONF_DONE line is actually causing it to not initialize because you've got the traces running all over.

I have two different experiments to try. I would try number 1 first.

1 - Can you add a capacitor between CONF_DONE and ground? Doesn't have to be too big. maybe 100pF. Though I don't think a larger value could hurt. You could probably actually lay it on top of R418. This would bypass to 3.3 instead of GND but I think either way will work. Try both if one doesn't have any effect.

2 - Try changing change R148 to 1K.

Jake