Mixed-size placement
Beginner
Putting a few big blocks and millions of tiny parts in place at the same time.
Novice
Placing a design that contains both large macros and millions of small standard cells. The macros may be placed first and locked, or placed together with the cells.
Expert
Sequential flows place the cells, cluster them, floorplan the macros inside a fixed outline, lock them and re-place the cells. Concurrent flows move macros and cells in one analytical placer and then legalize the macros, snapping them to legal, non-overlapping positions.
Explained in Floorplanning (Design Flow).
See also: Macro (hard macro), Global placement.