Electronic devices having semiconductor magnetic memory units

An electronic device comprising a semiconductor memory unit that includes:

• a plurality of resistance variable elements each configured to exhibit different resistance values corresponding to variability of a physical property of each resistance variable element, wherein each resistance variable element is operable, in a data recording operation, to respond to a data recording signal that is applied to the resistance variable element to change the physical property to take on a desired resistance value selected from the different resistance values to store a desired data bit represented by the desired resistance value, and, in a read operation, to respond to a read signal applied to the resistance variable element to sense the desired resistance value without changing the physical property and without changing the desired resistance value;
• and
• a memory device control circuit coupled to the resistance variable elements to read data from the resistance variable elements by controlling data recording signals applied and to control recording data into the resistance variable elements by controlling read signals applied, wherein the memory device control circuit includes:
• a plurality of first reference resistance elements each structured to exhibit a first resistance reference value, the first reference resistance elements corresponding to the resistance variable elements, one first reference resistance element per one resistance variable element, to provide a first resistance value reference in reading the resistance variable elements;
• a plurality of second reference resistance elements each structured to exhibit a second resistance reference value greater than the first resistance reference value, the second reference resistance elements also corresponding to the resistance variable elements, one second reference resistance element per one resistance variable element, to provide a second resistance value reference in reading the resistance variable elements;
• a power supply circuit coupled to supply reading and data recording signals to the variable resistance elements, and to supply power to the first reference resistance elements and the second reference resistance elements in reading data from the variable resistance elements to cause, in reading data stored in a selected variable resistance element, a first reference resistance element corresponding to the selected variable resistance element to produce a first reference signal representing the first resistance reference value and a second reference resistance element corresponding to the selected variable resistance element to produce a second reference signal representing the second resistance reference value;
• and
• a comparison circuit coupled to the variable resistance elements, the first reference resistance elements and the second reference resistance elements to receive an output reading signal from the selected resistance variable element and the first and second reference signals from the first and second reference resistance elements corresponding to the selected resistance variable element, the comparison circuit operable to process the received output reading signal, first and second reference signals to compare a resistance value of the selected resistance variable element to the first and second reference resistance values in reading data stored therein.