A nondestructive self-reference scheme for Spin-Transfer Torque Random Access Memory (STT-RAM)

We proposed a novel self-reference sensing scheme for Spin-Transfer Torque Random Access Memory (STT-RAM) to overcome the large bit-to-bit variation of Magnetic Tunneling Junction (MTJ) resistance. Different from all the existing schemes, our solution is nondestructive: The stored value in the STT-RAM cell does NOT need to be overwritten by a reference value. And hence, long write-back operation (of the original stored value) is eliminated. The robustness analyses of the existing scheme and our proposed nondestructive scheme are also presented. The measurement results from a 16kb testing chip successfully confirmed the effectiveness of our technique.