As long as the setting corresponds to the input, it is possible to change the frequency with the input value.
However, since the accuracy is determined by the reference clock and frequency divider, it is essential to make a judgment based on the desired accuracy (tolerance).
As described in the user's guide, the accuracy of the frequency is fres = fclk/2^M, depending on the resolution M of the modulation input accumulator, so it depends on the accuracy of fclk and the selection of M.
(Reference) NCO IP CoreUser Guide
https://www.intel.com/content/dam/www/programmable/us/en/pdfs/literature/ug/ug_nco.pdf
(Search for "fres" or "minimum possible (Search by fres, minimum possible output frequency, etc.)
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Category: DSP
Tools: Quartus® Prime
Devices: -