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Altera_Forum
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15 years ago

cyclone altpll max freq?

I am using cyclone ep1c20 grade 8, with an external clock 27M. The altpll provides two clock outputs, 135M (c0) and 405M (c1 = 27x15). and 405M is to be used as a sampling clock for signal tap...
Altera_Forum's avatar
Altera_Forum
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15 years ago

the clock tree is only rated to 402MHz, not exactly sure where the 275MHz is coming from. from a quick check in the data sheet 275MHz is the fmax for the input clock of an emulated LVDS in x2-x10 modes.