High capacity low cost multi-state magnetic memory

摘要

A multi-state current-switching magnetic memory element includes a stack of magnetic tunneling junction (MTJ) separated by a non-magnetic layer for storing more than one bit of information, wherein different levels of current applied to the memory element cause switching to different states.

主权项

1. A method of writing to a magnetic memory cell comprising:
receiving a current having a level from a current source; amplifying the received current level; using a first switch coupled to an end of the magnetic memory cell and based on the received current level, controlling current flow through the magnetic memory cell, the magnetic memory cell including a first and a second magnetic memory elements coupled to each other in series and an access transistor; using a second switch coupled to an opposite end of the magnetic memory cell, controlling current flow through the magnetic memory cell, wherein the position of the second switch controls the current flow through the magnetic memory cell; setting the positions of the first switch and the second switch such that the magnetic memory cell switches states to define a desired state of the magnetic memory cell;
programming the magnetic memory cell to an intermediate state by switching the positions of one or both of the first and second switches; andprogramming the magnetic memory cell by switching the positions of one or both of the first and second switches to a final state after programming the magnetic memory cell to the intermediate state.