Retrieving data stored in a magnetic integrated memory

1. A method of retrieving data stored in a magnetic integrated memory, the method comprising:

applying a perturbing hard-axis magnetic field to a giant magneto-resistive (GMR) memory element in a magnetic integrated memory; and

detecting a change in an electrical parameter caused by said perturbing hard-axis magnetic field.

2. The method of claim 1 , wherein the electrical parameter is selected from a group consisting of resistance, current, and voltage.

3. The method of claim 1 , further comprising:

determining a stored data value based on whether the change is above or below a predetermined threshold.

4. The method of claim 1 , further comprising:

determining a stored data value based on whether the change is in-phase or out-of-phase with a signal representing the perturbing hard-axis magnetic field.

5. A memory comprising:

an array of memory cells organized in columns and rows, each memory cell having a hard magnetic layer and a soft magnetic layer separated by a conductive layer;

a sense line that couples said conductive layers in a column of memory cells in series;

an affect line configured to perturb a magnetic field along hard axes of magnetic layers in a row of memory cells during a nondestructive read operation; and

a sense circuit coupled to the sense line to detect a change in resistance induced by the affect line during said read operation.

6. The memory of claim 5 , wherein the sense circuit determines a digital value stored in a memory cell based on the sign of the change in resistance.

7. The memory of claim 5 , wherein the sense circuit is further coupled to the affect line to detect a perturbation current, and wherein the sense circuit determines a digital value stored in a memory cell based on the relative phase between the change in resistance and the perturbation current.

8. The memory of claim 5 , wherein the affect line carries at least two current pulses during each read operation of a memory cell in that row.

9. The memory of claim 8 , wherein the sense circuit combines change measurements corresponding to the at least two current pulses to determine a digital value stored in a memory cell.

10. A method of retrieving data stored in a magnetic integrated memory, the method comprising:

applying an alternating hard-axis magnetic field to a magnetic element in a magnetic integrated memory; and

detecting an alternating change in an electrical parameter caused by said alternating hard-axis magnetic field.

11. The method of claim 10 , further comprising:

determining a stored data value based on whether the alternating change is in-phase or out-of-phase with the alternating hard-axis magnetic field.

12. The method of claim 11 , wherein said determining includes accumulating change information over multiple cycles of the alternating hard-axis magnetic field.

13. The method of claim 10 , wherein the magnetic element is part of a memory cell that stores a data value as a persistent magnetization that is parallel or anti-parallel to a persistent magnetization of a second magnetic element associated with the memory cell.

14. The method of claim 13 , wherein the magnetic element and the second magnetic element are separated by a nonconductive layer.

15. The method of claim 13 , wherein the magnetic element and the second magnetic element are separated by a conductive layer.