In 1958, Seymour Ginsburg proved that don't-care circuit minimization does not necessarily yield a minimal result. The designer of a logic circuit to implement the function need not care about such inputs, but can choose the circuit's output arbitrarily, usually such that the simplest circuit results ( minimization).ĭon't-care terms are important to consider in minimizing logic circuit design, including graphical methods like Karnaugh–Veitch maps and algebraic methods such as the Quine–McCluskey algorithm. Both these types of conditions are treated the same way in logic design and may be referred to collectively as don't-care conditions for brevity. An input that is known never to occur is a can't-happen term. In digital logic, a don't-care term (abbreviated DC, historically also known as redundancies, irrelevancies, optional entries, invalid combinations, vacuous combinations, forbidden combinations, unused states or logical remainders ) for a function is an input-sequence (a series of bits) for which the function output does not matter.

Logic circuit maker