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Diego2's avatar
Diego2
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5 years ago
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PLL input clock inclk[0] is not f ully compensated because it is fed by a remote clock pin

Hello I have a design for a Cyclone 10 LP FPGA with a PLL that is fed from a clock-dedicated pin. The PLL was generated in "Normal Mode", however I'm getting this Critical Warning Critical Warnin...
  • Ash_R_Intel's avatar
    5 years ago

    Hi Diego,


    Please refer Figure 38 of Intel® Cyclone® 10 LP Core Fabric and General Purpose I/Os Handbook (https://www.intel.com/content/dam/www/programmable/us/en/pdfs/literature/hb/cyclone-10/c10lp-51003.pdf)


    Each PLL has dedicated input pins, indicated by a solid line and dotted line. The solid line are the dedicated pins for that particular PLL. For example, PLL_1 has CLK[3:0]. However, PLL_1 can also be driven by other dedicated pins CLK[15:12}, but they are not associated ones for PLL_1.


    Refer statement in section 4.2.4 "Input and output delays are fully compensated by the PLL only if you are using the

    dedicated clock input pins associated with a given PLL as the clock sources."


    To avoid the warning, use associated dedicated pins for the PLL.


    Regards