Random code generator and associated random code generating method

A random code generating method, comprising steps of:

• providing a supplying voltage by a power source;
• providing a sensing circuit;
• and
• providing a memory cell array comprising a first memory cell and a second memory cell, wherein a first terminal of the first memory cell is connected with the power circuit through a first power line, a second terminal of the first memory cell is connected with the sensing circuit through a first bit line, a third terminal of the first memory cell is connected with a first word line, a first terminal of the second memory cell is connected with the power circuit through a second power line, a second terminal of the second memory cell is connected with the sensing circuit through a second bit line, and a third terminal of the second memory cell is connected with the first word line;
• receiving an ON voltage by first word line, and receiving the supplying voltage by the first power line and the second power line during an enrollment;
• verifying by a first sense amplifier of the sensing circuit that the enrollment is completed if a first current generated by the first memory cell exceeds a threshold value;
• verifying by a second sense amplifier of the sensing circuit that the enrollment is completed if a second current generated by the second memory cell exceeds the threshold value;
• and
• determining a random code by the first sense amplifier and the second sense amplifier according to a resistance difference between the first memory cell and the second memory cell after the enrollment.