Reduction in the number of LUT elements for control units with code sharing

Two methods are proposed targeted at reduction in the number of look-up table elements in logic circuits of compositional microprogram control units (CMCUs) with code sharing. The methods assume the application of field-programmable gate arrays for the implementation of the combinational part of the CMCU, whereas embedded-memory blocks are used for implementation of its control memory. Both methods are based on the existence of classes of pseudoequivalent operational linear chains in a microprogram to be implemented. Conditions for the application of the proposed methods and examples of design are shown. Results of conducted experiments are given.