Algorithms for synthesis of four-valued one- and two-variable functions for CCD (charge coupled device) implementation are proposed. One-variable synthesis is based on the observation that the cost of a realization of a function f(x) increases in the presence of breaks, or negative transitions, in the value of f as x increases. The function is decomposed to minimize the number of such transitions. Two-variable functions are synthesized as a sum of products of literals, taking advantage of literals that are easily implemented in CCD technology. It is concluded that the proposed algorithms perform better than those published previously. >