If the "Automatically select a location" option is chosen in the Memory Topology/ Topology tab of the Arria® 10 DDR4 IP Editor, the IP will automatically choose a pin assignment for the mem_alert_n signal. If this option is selected and there are conflicting location constraints applied to the mem_alert_n pin, then fitter errors will result during compilation.
The fitter errors will include these messages:
Error (14566): The Fitter cannot place 1 periphery component(s) due to conflicts with existing constraints (1 pin(s)).
Error (15307): Cannot apply project assignments to the design due to illegal or conflicting assignments. Refer to the other messages for corrective action.
If you choose to use the "Automatically select a location" option, remove all location assignments and constraints for the mem_alert_n signal in your .QSF file. Intel FPGA recommends manually placing the mem_alert_n signal in the address/command bank for optimum timing margins by choosing the "I/O Lane with Address/Command Pins" option.