Method for changing an integrated circuit design

A method for changing an integrated circuit design, the method comprising:

• providing a plurality of functional cells for the integrated circuit design;
• replacing a plurality of spare cells for the integrated circuit design with a plurality of gate-based decoupling cells, wherein each of the gate-based decoupling cells includes an n-type diffusion region, a p-type diffusion region, and a plurality of poly silicon lines, each poly silicon line of the plurality of poly silicon lines extending over both the n-type diffusion region and the p-type diffusion region, the n-type and p-type diffusion regions both connected to a first power supply line and the plurality of polysilicon lines connected to a second power supply line, wherein the first power supply line is for receiving a power supply voltage that is different from a power supply voltage received by the second power supply line;
• and
• reconfiguring the gate-based decoupling cells for the integrated circuit design to a logic function in response to an engineering change order (ECO), wherein each of the gate-based decoupling cells is reconfigured by removing the second power supply line connections to the polysilicon lines and the first power supply line connections to the n-type and p-type diffusion layers, and adding new connections to implement the logic function.