Bit line charge accumulation sensing for resistive changing memory

A memory array comprising:

• a plurality of magneto-resistive changing memory, each magneto-resistive changing memory cell electrically between a source line and a bit line and a transistor electrically between the resistive changing memory cell and the bit line, the transistor having a gate electrically between a source region and a drain region, and the source region being electrically between the resistive changing memory cell and the gate, a word line is electrically coupled to the gate;
• a plurality of high resistance state resistive changing memory cells, each high resistance state resistive changing memory cell is electrically connected to a high resistance state transistor and the high resistance state transistor is electrically coupled to a reference voltage word line;
• and
• a plurality of low resistance state resistive changing memory cells, each low resistance state resistive changing memory cell is electrically connected to a low resistance state transistor and the low resistance state transistor is electrically coupled to the reference voltage word line;
• wherein one high resistance state resistive changing memory cell and one low resistance state resistive changing memory cell provide an average voltage reference value when a read operation is applied across a selected resistive changing memory cell along a same word line row connecting the transistor, the high resistance state transistor, and the low resistance state transistor.

A method of sensing a data state of resistive changing memory, comprising steps of:

• precharging a bit line to a predetermined bit line charge level having a bit line precharge voltage value;
• applying a current to a word line, the word line being electrically coupled to a gate of a transistor, the current discharging the bit line charge through a selected magneto-resistive changing memory cell and reducing the bit line precharge voltage value to a bit line voltage value;
• and
• sensing the bit line voltage value to determine a data state of the magneto-resistive changing memory.