1. A programmable look up table (LUT) structure of an integrated circuit, comprising: a plurality of LUT circuits, each LUT circuit comprising: one or more logic inputs; and two or more configurable LUT values; and at least one output; and one or more configurable data storage units comprising a digital output; and a configurable multiplexer (MUX) circuit comprising: one or more select inputs; and one or more outputs; and two or more inputs, wherein a first input is coupled to the output of a said LUT circuit, and a second input is coupled to the output of a said data storage unit.