Memory devices having a read function of data stored in a plurality of reference cells

An apparatus, comprising:

• a first memory cell configured to store user data;
• at least two second memory cells among a plurality of second memory cells coupled together by a parallel circuit, the at least two second memory cells configured to provide, via the parallel circuit, a reference signal for reading the user data stored in the first memory cell during a normal read mode;
• and
• a control circuit configured to perform a detecting operation to detect whether one of the at least two second memory cells is defective or not by reading data stored in the one of the at least two second memory cells and to perform a correcting operation to correct the data stored in the one of the at least two second memory cells if the one of the at least two second memory cells is detected to be defective, wherein the control circuit is configured to operate a switch electrically connected between a defective one of the plurality of second memory cells and the parallel circuit connecting the plurality of second memory cells to separate the defective one of the plurality of second memory cells from the parallel circuit.

An apparatus, comprising:

• a sense amplifier configured to read user data using a reference signal;
• a first memory cell configured to store the user data;
• a plurality of second reference memory cells which are connected with each other, via a plurality of first switches, to form a parallel circuit to provide the reference signal;
• and
• a control circuit configured to separate a defective second reference memory cell of the plurality of second reference memory cells from the parallel circuit,
• wherein each of the plurality of first switches is coupled between neighboring second reference memory cells of the plurality of second reference memory cells, and
• wherein the control circuit is configured to form the parallel circuit by turning on each of the plurality of first switches.