See Also

LogicLock^™ regions can be nested hierarchically. Hierarchical LogicLock region assignments allow you to create regions inside of regions and to construct a constraint hierarchy that parallels your project's design hierarchy.

For example, you can try to optimize the performance of an entity by constraining the entity to a parent LogicLock region and constraining all nodes on the entity's critical path to a smaller child LogicLock region inside the parent region. Alternatively, you can use hierarchical LogicLock region assignments to place LogicLock regions imported from another project inside LogicLock regions created in the current project.

When you make one region the parent of another region, you place the child region inside the parent region. For this reason, the Quartus^® II software does not allow you to make a smaller region the parent of a larger region. If the region you select as the child region is located outside the region you select as the parent region, the Quartus II software moves the child region's origin to the same location as the parent region's origin.

Once you have specified the parent region for a LogicLock region, the Quartus II software interprets the child region's location as relative to its parent region's origin. When you lock the location of a child region, the child region's location is only locked relative to its parent's top left corner, not relative to the target device. When you move a parent region to a new location, the Quartus II software updates the locations of the region's descendant regions to maintain their positions relative to the parent region. When you resize a region, the Quartus II software checks that the new dimensions still include all the region's descendant regions and do not exceed the boundaries of its parent region.

The Quartus II software performs LogicLock back-annotation recursively on the LogicLock region hierarchy. When you back-annotate a region's location or contents, the Quartus II software automatically back-annotates the location or contents of the region's descendant regions.

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