ID:176100 Non clock differential I/O pin <name> does not connect to any SERDES receiver or transmitter

CAUSE: The Fitter is reporting that your design contains a non clockdifferential I/O pin that does not connect to a SERDES receiver or transmitter. Non clock differential I/O pins that are not connected to a SERDES receiver or transmitter have less stringent placement restrictions than non clock differential I/O pins that are connected to a SERDES receiver or transmitter. If you modify your design to connect the non clock differential I/O pins to the SERDES receiver or transmitter, the Fitter may not be able to fit your design in the device.

ACTION: If you do not want to connect non clock differential I/O pins to a SERDES receiver or transmitter, no action is required. Otherwise, modify your design to ensure that the non clock differential I/O pins are connected to a SERDES receiver or transmitter.