Unassign an I/O macro from a locked assignment when its locked position is no longer required. Unassigned macros are automatically placed in optimum locations during layout.
To unassign a macro from a pin:
Select the I/O macro in the Assigned list box.
Unassign the selected macro from a pin location using any one of these methods:
Drag the selected macro name from the Assigned list box to the Unassigned list box.
From the Edit menu, choose Unassign.
Click the Unassign toolbar button.
Press the DELETE key.
In the I/O Attribute Editor, select Unassign in the Pin # cell.
The macro is unassigned.