Voltage-domain floorplanning

Floorplan a multi-voltage block. Every block belongs to a fixed voltage domain: the blue core runs at 0.8V, the orange io at 1.2V. A domain cannot be scattered - each must occupy its own contiguous region - and the few nets that cross between domains need a level shifter, so they should be short.

The blocks start interleaved, so the two domains overlap and the cross-domain wires are long.

• Domains kept separate - group each colour into its own region so the two dashed domain boxes do not overlap. A power domain has to be one contiguous area, not fragmented.
• Level-shifter nets short - the red nets cross between domains. Put the blocks they connect near the shared boundary so those wires stay short.
• Legality - blocks inside the die, not overlapping.

Shorter cross-domain wire scores higher. Submit design once the domains are separated and the crossings are short.