Multiple Supply Voltage (MSV) design is an effective ways to deal with SoC power challenge

but brings overhead on wirelength area

etc.To reduce wirelength

chip's dead space ratio and improve algorithm speed

an improved fixed outline multi-voltage floorplanning algorithm is proposed.For a given floorplan solution represented by NPE (Normalized Polish Expression)

We use the shape curve adding algorithm to calculate its optimal floorplan implementation

and adopt an incremental calculation method in the process of NPE calculation and voltage assignment to reduce runtime.An improved objective function including fixed-outline constraint is proposed

and the IAD (Insertion After Delete) operator is used to post-optimize the obtained floorplan of SA.Experimental results show that compared with the existing methods

our algorithm has advantages on wirelength and dead space ratio

and all circuits achieve extremely low dead space ratio (1%) under different aspect ratio and different voltage island number.