Due to a problem in the Quartus® II software Pin Planner tool, some differential signals may appear twice in the Pin Planner for the UniPHY-based memory controller. For example,
mem_dqs_n(n) as well as
mem_ck_n(n) signals may appear after the <variation name>_pin_assignments.tcl is run. The Pin Planner may also show the following pins as differential pairs:
This duplication occurs because the <variation name>_pin_assignments.tcl file sets the IO_STANDARD assignments as DIFFERENTIAL for these signals. The Pin Planner then automatically creates a negative pin for these signals.