Cyclone IV JTAG Working, Configuration Not

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Hi,

don't wont to bother anyone, but comparing the M25P40 data (2.3V, Grade6 => fmax = 25MHz acc. page 42) with the cyclone's internal oscillator's frequency (40MHz, ch.8) there might be a mismatch which most likely will not cause any Problems in real life many times, but it is not 100% save, is it?

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That’s a great spec to check. I find that it meets or exceeds Altera’s EPCS parts running at 3.3V according to printed specifications.

The maximum “read clock” frequency for Altera EPCS parts at 3.3V is 20 MHz, and the maximum “fast read clock” frequency is 40 MHz. In comparison, the M25P40 2.3V operation section of the spec shows a maximum “read clock” frequency of 25 MHz and maximum “fast read clock” frequency of 40 MHz.

That makes the M25P40 at 2.5V appear at least as guaranteed as an EPCS4 at 3.3V.