1. An electronic device comprising a semiconductor memory unit that includes: a plurality of data transfer lines; a plurality of columns each column including a plurality of memory cells; one or more redundancy columns each including a plurality of redundancy memory cells for replacing a column of memory cells when the column fails to operate properly; a repair select information generation unit configured to store a column address of a column to be replaced among the plurality of columns and generate a plurality of repair select information in response to the stored column address; and a plurality of repair selection units coupled to the plurality of columns, respectively and coupled to a redundancy column, each repair selection unit selectively providing an electrical connection to a corresponding column or the redundancy column based on the repair select information.