ID:21201 Output port <name> of DDIO_OE primitive "<name>" must drive input port <name> of an I/O OBUF primitive, or <name> of a PSEUDO_DIFF_OUT primitive.

CAUSE: The specified DDIO_OE atom is not connected properly. It should drive the specified port of an I/O OBUF primitive or a PSEUDO_DIFF_OUT primitive, but it is not doing so.

ACTION: Check your design to make sure that the DDIO_OE atom is properly connected.