Hierarchical Floorplanning - 2023.2 English

Vivado Design Suite User Guide: Design Analysis and Closure Techniques (UG906)

Document ID
Release Date
2023.2 English

Hierarchical floorplanning allows you to place one or more levels of hierarchy in a region on the chip. This region provides guidance to the placer at a global level, and the placer does the detailed placement. Hierarchical floorplanning has the following advantages over gate-level floorplanning:

  • Hierarchical floorplan creation is fast compared to gate-level floorplanning. A good floorplan can improve timing. The floorplan is resistant to design change.
  • The level of hierarchy acts as a container for all the gates. It will generally work if the netlist changes.

In hierarchical floorplanning:

  • Identify the lower levels of hierarchy that contain the critical path.
  • Use the top level floorplan to identify where to place them.
  • Implementation places individual cells.
  • Has comprehensive knowledge of the cells and timing paths.
  • Generally does a good job of fine grain placement.