When your design uses the Electromigration Current option in the Quartus® II software, this warning message is reported during fitting and I/O Assignment Analysis.
You can use the Electromigration Current option to validate your pinout against the DC current density guidelines for each device family when the device is driving DC current to resistive loads. This option allows you to enter the amount of current that any I/O pin may drive according to your board design.
These warnings can be safely ignored if you intend to drive the pins with the specified current. The recommendation of 0.0 mA is provided based on typical applications where the I/O pins drive other CMOS devices which are capacitive loads, not resistive. If your intention is to drive a resistive load, then you should use this option to be sure your pinout does not violate the current density restrictions of your device.
If your pinout violates the current density for your device, the software reports the following error:
Error: Current density too high in I/O bank <name> -- pins combined exceed the limit (device current limit in mA) by <number> mA
If you receive this error, change your pin locations so that you do not violate the current density restrictions, or reduce the drive strength of the I/O pin(s).