Circuits and methods for a system on a chip having non-uniform channel spacings is provided. In an example, a chip is provided that includes a first functional block having a rectilinear shape, the first processing unit having on a side a plurality of channel spacings. A first channel spacing of the plurality of channel spacings is positioned in contact with the side and a second functional block. A second channel spacing of the plurality of channel spacings is positioned in contact with the side and the second functional block. The width of the second channel spacing is non-uniform with the width of the first channel spacing.