ID:15916 Input port <text> and output port <text> of PLL "<name>" are not connected properly

CAUSE: When the operation_mode parameter of the specified PLL is set to zero_delay_buffer, the fbout output of the specified PLL must be connected to the fbin input of the same PLL through a bidirectional I/O.

ACTION: Make sure that the fbout is connected to fbin through a bidirectional I/O. Use the ALT_IOBUF megafunction to instantiate the bidirectional I/O.