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Altera_Forum
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16 years ago

Altera CycloneIII FPGA PLL problem

The PLL input clock is 27M. It is multipied and output a clock of 270M to supply the ASI IP core. 8 PCB boards are in test and downloaded the same FPGA program. The problem is, 4 out of 8 boards can ...
Altera_Forum's avatar
Altera_Forum
Icon for Honored Contributor rankHonored Contributor
16 years ago

Ok, input clock is good, solder joint are good.

Are all devices under test of the same speed?

Are the PLL power supplies ok (Vcca and Vccd)? Voltage? Decoupling? Grounding?

That's all I can think of.

Try some other input- and/or output-frequencies. Does the problem remain?

-- Ton