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Altera_Forum's avatar
Altera_Forum
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16 years ago

pll reconfiguration and CP/LF parameters

Documentation describing the pll scan chain is clear enough for the settings of the m,n,cx counters. However, it is not clear to me how the charge-pump and loop-filter parameters should be calculated...
Altera_Forum's avatar
Altera_Forum
Icon for Honored Contributor rankHonored Contributor
16 years ago

Hi,

I've been trough this mess too! And this is the reply i got from my gold membership FAE guy: "the lab people at altera say the megawizard uses a complicated set of tables to determine the right C and I for each set of input and output frequencies and VCO speed". unfortunately they didn't want to share these tables. I wrote a batch compilation script to compile and readback all scenarios i needed. A very boring task, but still better then doing 400 megawizard loops by hand!