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Altera_Forum
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16 years ago

PLL megacore probs.build my own??

Hi all, I want to implement a PLL that will lock onto & track an incoming signal of about 30KHz and output a multiple of that locked frequency. I tried using Quartus's PLL megacore function but...
Altera_Forum's avatar
Altera_Forum
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16 years ago

Yes, there's a misunderstanding.

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you only need the phase accumulator from the NCO

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I didn't mean, that you must necessarily use this phase accumulator (from the Altera NCO core). You can use any phase accumulator. I didn't think about the fact, that the Altera NCO doesn't have an output from the phase accumulator. If you're not familiar with NCO internals, you can see from the NCO MegaCore User Guide's functional description, that the phase accumulator isn't but a register and an adder. The more complex part of the NCO follows, but it's not needed for a pure digital PLL.