1. An integrated circuit comprising: components, each component having inputs and outputs, at least one component being a customizable component; a multiplicity of fixed interconnection layers to provide interconnections among components; and a single via layer to provide all customizable interconnections of the integrated circuit and to customize each customizable component of the integrated circuit, said single via layer to be disposed between two of said multiplicity of fixed interconnection layers, wherein said components include at least one customizable storage element, and wherein the at least one customizable storage element includes at least one wire segment, wherein a signal propagation direction on the at least one wire segment is a first direction in a first configuration of the at least one customizable storage element and is a second direction, opposite to the first direction, in a second configuration of the at least one customizable storage element.