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