Memory controllers

A system, comprising:

• a memory crossbar array, wherein the memory crossbar array comprises a plurality of row lines, a plurality of column lines, and a plurality of memory cells, wherein each memory cell is coupled between a unique combination of one row line and one column line;
• and
• a memory controller, wherein the memory controller comprises:
• a voltage driver to apply a variable voltage to a selected line of the memory crossbar array to determine a first measured voltage that drives a first read current through a selected memory cell and to apply the variable voltage to the selected line to determine a second measured voltage that drives a second read current through the selected memory cell;
• and
• a voltage comparator to determine a voltage difference between the first measured voltage and the second measured voltage and to compare the voltage difference with a reference voltage difference to determine the state of the selected memory cell.

A method for determining a state of a memristor, comprising:

• determining a first measured voltage that drives a first read current through a selected memory cell of a crossbar array by applying a variable voltage to a selected line of the crossbar array;
• determining a second measured voltage that drives a second read current through the selected memory cell by applying the variable voltage to the selected line;
• and
• comparing a voltage difference between the first measured voltage and the second measured voltage with a reference voltage difference,
• wherein the crossbar array comprises a plurality of row lines, a plurality of column lines, and a plurality of memory cells coupled between a unique combination of one row line and one column line.