An Intel® Stratix® 10 FPGA High-Speed LVDS I/O interface can be set to a different data rate or phase shift, but only if the Use External PLL option is selected in the LVDS SERDES Intel® FPGA IP core parameter editor. If this option is not selected, changing the data rate or phase shift might cause the Dynamic Phase Alignment (DPA) circuitry to fail to lock, even if the correct reset and initialization sequence is followed.
For more information on the Use External PLL mode, refer to the Intel® Stratix® 10 High-Speed LVDS I/O User Guide, section 3.1.7 ,
For more information on the reset and initialization sequence, refer to the Intel® Stratix® 10 High-Speed LVDS I/O User Guide, section 4.2.2.