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A_MISHRA's avatar
A_MISHRA
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6 years ago

Error(175019): Illegal constraint of I/O pad to the location PIN_K12

Custom design using Arria 10 SOC, 10AS066KF40-

The clkout pin (PLL_3H_CLKOUT0P,PLL_3H_CLKOUT0,PLL_3H_FB0/LVDS3H_15P/DQ68

) which is also defined as LVDS in pin description, when used as LVDS differential input throws fitter error,

Error(175019): Illegal constraint of I/O pad to the location PIN_K12

How to disable default clockout feature of corresponding pin and enable it to accept LVDS differential input?

3 Replies

  • Rahul_S_Intel1's avatar
    Rahul_S_Intel1
    Icon for Frequent Contributor rankFrequent Contributor
    6 years ago

    Hi ,

    Kindly check PIN _K12 is in 3V IO bank. If it is in 3VIO bank there is no LVDS IO support for Arria 10 .

    • A_MISHRA's avatar
      A_MISHRA
      Icon for New Contributor rankNew Contributor
      6 years ago

      Thank you for your kind reply. Actually issue was with pin mapping. We have used ADS42LB69, its having LVDS clocks and data. By mistake we have mapped P(positive) pin of ADC data line to LVDS3H_15N means Positive pin was mapped to Negative pin of LVDS Bank 3H and vice versa. After swapping these pins in pin planner issue was resolved.