A semiconductor device includes: a processing core having a plurality of sub cores, a plurality of power rails spanning from a first sub core to a second sub core of the plurality of sub cores, the plurality of power rails configured to provide an operating voltage to each of the first sub core and the second sub core, and a plurality of cells defining a boundary between the first sub core and the second sub core, each of the cells providing a discontinuity in a respective power rail, wherein the discontinuity includes a break in the respective power rail in more than one layer of the semiconductor device.