You can make a location assignment for fractional PLLs in Stratix® V devices in the Quartus® II software by using the Assignment Editor and perform these steps:
- In the Assignment Editor, set the Category to "Locations".
- In the "To" column, select the PLL instance using the node finder. It is helpful to narrow down the search by selecting *.gpll* as the filter.
- In the "Assignment Name" column, select "Location".
- Double click in the "Value" column and select "Fractional PLL" as the "Element" from the dropdown list. This will allow you to specify valid X, Y, and N locations from a dropdown list.
- Add "~FRACTIONAL_PLL" to the PLL instance assignment to assign the PLL location correctly.
For example, the node name in the "To" column should look similar to the following:
An example of the .qsf setting would be:
set_location_assignment FRACTIONALPLL_X0_Y122_N0 -to " altpll0:inst|altpll0_0002:altpll0_inst|altera_pll:altera_pll_i|general.gpll~FRACTIONAL_PLL"