A memory device includes a plurality of sense amplifiers, a plurality of memory cells, a plurality of data lines, a plurality of reference cells, and a connection line. The memory cells are coupled to a plurality of first inputs of the plurality of sense amplifiers respectively. The data lines are coupled to a plurality of second inputs of the plurality of sense amplifiers respectively. The reference cells are arranged in a plurality of columns respectively and coupled to the plurality of data line respectively. Each of the plurality of reference cells includes a plurality of resistive elements. The connection line is coupled to the plurality of data lines. In a read mode, one of the sense amplifiers is configured to access the plurality of resistive elements arranged in at least one of the plurality of columns.