A method and circuits are disclosed for sensing an output of a memory cell having high and low resistance states. A high reference cell is in high resistance state and a low reference cell is in low resistance state. The resistance of the high reference cell in high resistance state has a first margin of difference from the resistance of the memory cell in high resistance state. The resistance of the low reference cell in low resistance state has a second margin of difference from the resistance of the memory cell in low resistance state. Differential amplifiers coupled to the memory cell and the high and low reference cells provide a digital output representing the resistance state of the memory cell.