STRUCTURES AND METHODS FOR A FIELD-RESET SPIN-TORQUE MRAM
First Claim
1. A method of operating a spin-torque magnetoresistive memory including a bit line coupled to each of a plurality of magnetoresistive memory elements, circuitry coupled to the bit line, and a metal reset line positioned near the plurality of magnetoresistive memory elements, the method comprising:
- setting the plurality of magnetoresistive memory elements to a first state by applying a reset current through the metal reset line to apply a magnetic field to each of the plurality of magnetoresistive memory elements; and
programming selected ones of the plurality of magnetoresistive memory elements to a second state by applying a spin torque transfer current through the selected magnetoresistive memory elements from the circuitry to the bit line.
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Abstract
An apparatus and method of programming a spin-torque magnetoresistive memory array includes a metal reset line positioned near each of a plurality of magnetoresistive bits and configured to set the plurality of magnetoresistive memory elements to a known state by generating a magnetic field when an electrical current flows through it. A spin torque transfer current is then applied to selected ones of the magnetoresistive bits to switch the selected bit to a programmed state. In another mode of operation, a resistance of the plurality of bits is sensed prior to generating the magnetic field. The resistance is again sensed after the magnetic field is generated and the data represented by the initial state of each bit is determined from the resistance change. A spin torque transfer current is then applied only to those magnetoresistive bits having a resistance different from prior to the magnetic field being applied.
38 Citations
24 Claims
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1. A method of operating a spin-torque magnetoresistive memory including a bit line coupled to each of a plurality of magnetoresistive memory elements, circuitry coupled to the bit line, and a metal reset line positioned near the plurality of magnetoresistive memory elements, the method comprising:
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setting the plurality of magnetoresistive memory elements to a first state by applying a reset current through the metal reset line to apply a magnetic field to each of the plurality of magnetoresistive memory elements; and programming selected ones of the plurality of magnetoresistive memory elements to a second state by applying a spin torque transfer current through the selected magnetoresistive memory elements from the circuitry to the bit line. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15)
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16. A spin-torque magnetoresistive memory comprising:
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a plurality of magnetoresistive memory elements; a metal reset line positioned adjacent each of the plurality of magnetoresistive memory elements and configured to set the plurality of magnetoresistive memory elements to a known state by generating a magnetic field when an electrical current of predetermined magnitude and direction flows through the metal reset line; a bit line coupled to the plurality of magnetoresistive memory elements; and circuitry coupled to the bit line and configured to apply a spin torque transfer current through the bit line to selected ones of the plurality of magnetoresistive memory elements. - View Dependent Claims (17, 18, 19, 20, 21, 22, 23)
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24. A method of operating a resistive memory including a bit line coupled to each of a plurality of resistive memory elements, circuitry coupled to the bit line, and a metal reset line positioned near the plurality of resistive memory elements, the method comprising:
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resetting the plurality of resistive memory elements to a first state by applying a first current through the metal reset line to apply a temperature profile; and programming selected ones of the plurality of resistive memory elements to a second state by applying a current through the selected resistive memory elements from the circuitry to the bit line.
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Specification