5.5.3.2 Physical Constraints

QDR subsystem can be placed only in the pre-defined locations that are optimized for maximum performance. The maximum width of the QDR subsystem varies based on die/package combination and placement. For information about the QDR placement, see the PolarFire, PolarFire SoC, and RT PolarFire Package Pin Assignment Tables.

The QDR subsystem location is selected using the I/O Editor. Libero assigns I/Os based on the selection of DDR memory location. The following steps explains the selection of the QDR Subsystem Location:

1. Click Design Flow > Constraint Manager > I/O Attributes > Edit with I/O Editor.

   

2. Select the Memory View tab in I/O Editor. Select the appropriate Memory Type to get the valid locations for the chosen memory.
3. Select the appropriate QDR instance from the Design View window, and drag it onto Port Function. For the selected QDR instance, I/O Editor shows the valid locations in green.