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Altera_Forum
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18 years ago

Cyclone III AS configuration bizarreness

I am using a cyclone III (EP3C25F324C8N) with an EPCS16 configuration device. I am programming the configuration device through the FPGA with the serial flash loader. The problem is that the Cyc...
Altera_Forum's avatar
Altera_Forum
Icon for Honored Contributor rankHonored Contributor
18 years ago

Not really but here's the latest theory: Apparently there's some sort of race condition in the Cyclone 3's configuration circuitry. I mistakenly used 3.3V for the configuration voltages but the specification is for these signals (nStatus, COMF_DONE, nCONFIG, DATA1, DCLK, nCSO, ASD)) to be driven by (or pulled up to) a 2.5V standard. This may have contributed to the timing problem.

When I spin the board I'll fix the voltage AND add the capacitor; then, hopefully, I'll see what's what.