Cell flipping (orientation)

Detailed placement: cell flipping. The cells are already placed in their legal slots and cannot move. But each one can be mirrored (flipped horizontally), which swaps the sides its pins sit on: the blue input pin A and the red output pin Y trade edges. A cell whose partner sits on the far side wastes wire reaching around itself.

• Wirelength under target - click cells to flip them so each pin faces the cell (or boundary pin) it wires to, pulling the nets short and dropping total wirelength under target.

The cells start in a poor orientation. Reorient them, then Submit design.