
174 CHAPTER 4 / LOGIC FUNCTION REPRESENTATION AND MINIMIZATION
FIGURE 4.46
Four-variable K-maps for function Y illustrating four steps of the Espresso algorithm: (a) ORIGINAL,
(b) REDUCE, (c) EXPAND, and (d) IRREDUNDANT COVER.
capability. These improved Espresso algorithms include the two referred to as Espresso-
EXACT and Espresso-MV. A detailed description of these and other closely related algo-
rithms can be found in references cited at the end of this chapter.
4.9 FACTORIZATION, RESUBSTITUTION, AND DECOMPOSITION METHODS
Beyond the SOP or POS minimum result, it is possible to further reduce the gate/input tally,
reduce the number of inverters,