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ABhus's avatar
ABhus
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5 years ago

I am using IOPLL Intel FPGA IP for Aria 10 SoC device. I need a clock of 307.2MHz/30.72MHz with a ref Clock of 10/100MHz . How can I get the exact clock?

With many possible combinations as well, I could get Actual output clock as 307.5M/307.142M/307.189M but not exact value. M,N,C Counter values can be edited only as integer values but not fractional ...
EngWei_O_Intel's avatar
EngWei_O_Intel
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5 years ago

Hi Anamika

Sorry for late response. Can you try to set the PLL mode to Fractional-N PLL?

Thanks

Eng Wei

ABhus's avatar
ABhus
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5 years ago

Thanks for the response.

Actually, in IOPLL there is no option to set PLL mode as Fractional mode.

But there is one fPLL under Transceiver section in which we can use Fractional mode.

Is it ok to use fPLL for driving user logic?

When I tried using fPLL it is giving Fitter placement issues as shown below?

"Error(11215): Input port "REFCLK" of "CMU_FPLL_REFCLK_SELECT" cannot connect to PLD port "O" of "IO_INPUT_BUFFER" for atom "fpga_clk~input". "