ID:176685 Unable to place CK/CKn pair <name> and <name> on a differential pin pair because they have been assigned to different I/O banks or edges

CAUSE: You have placed CK and CKn pair into different I/O banks or edges. Because of this assignment, the CK and CKn pin cannot be placed on a differential pin pair.

ACTION: Remove the pin location assignments or place the CK and CKn pair into the same I/O banks or edges.