US 2018/0025764 A1 · MAGNETIC FIELD-ASSISTED MEMORY OPERATION

Abstract

In one embodiment, a magnetoresistance random access memory (MRAM) such as a spin transfer torque (STT) random access memory (RAM), for example, has a subarray of bitcells and an electro-magnet positioned adjacent the subarray. A magnetic field is directed through a ferromagnetic device of bitcells of the first subarray to assist in the changing of states of bitcells of the subarray from a first state to a second state in which the ferromagnetic device of the bitcell is changed from one of parallel and anti-parallel polarization to the other of parallel and anti-parallel polarization. Accordingly, the content of the subarray may be readily preset or erased to one of the parallel or anti-parallel state with assistance from an electro-magnet. During a normal write operation, the bits to the other state are written. Other aspects are described herein.

Claims25

Dependent claims

An apparatus comprising:

an array of magnetoresistive (MRAM) bitcells having a first subarray of MRAM bitcells wherein each bitcell includes a ferromagnetic device having a polarization which in a first state is one of parallel and anti-parallel polarization and in a second state is the other of parallel and anti-parallel polarization;
control circuitry configured to change the state of bitcells of the first subarray in the first state to the second state, so that ferromagnetic devices of bitcells of the first subarray have the polarization exhibited by a bitcell in the second state;
and
an electro-magnet positioned adjacent the first subarray to direct a magnetic field through the ferromagnetic device of the bitcells of the first subarray to assist in the changing of states of bitcells of the first subarray of the array of bitcells of the MRAM from the first state to the second state.

1 more element

A computing system for use with a display, comprising:

a memory;
a processor configured to write data in and read data from the memory;
and
a video controller configured to display information represented by data in the memory;
wherein the memory includes a magnetoresistive random access memory (MRAM), comprising:
an array of MRAM bitcells having a first subarray of MRAM bitcells wherein each bitcell includes a ferromagnetic device having a polarization which in a first state is one of parallel and anti-parallel polarization and in a second state is the other of parallel and anti-parallel polarization;
control circuitry configured to direct spin-polarized current through the ferromagnetic device of bitcells of the first subarray to change the state of bitcells of the first subarray in the first state to the second state, so that ferromagnetic devices of bitcells of the first subarray have the polarization exhibited by a bitcell in the second state;
and
an electro-magnet positioned adjacent the first subarray to direct a magnetic field through the ferromagnetic device of the bitcells of the first subarray to assist in the changing of states of bitcells of the first subarray of the array of bitcells of the STT MRAM from the first state to the second state.

6 more elements

A method of operating a magnetoresistive random access memory (MRAM), comprising:

magnetic field-assisted changing of states of bitcells of a first subarray of an array of bitcells of the MRAM from a first state to a second state so that the changed state bitcells of the first subarray exhibit the second state wherein the first state represents one of a logical one and a logical zero and the second state represents the other of a logical one and a logical zero, wherein each bitcell includes a ferromagnetic device having a polarization which in the first state is one of parallel and anti-parallel polarization and in the second state is the other of parallel and anti-parallel polarization, and wherein the magnetic field-assisted changing includes directing a magnetic field through the ferromagnetic device of bitcells of the first subarray to assist in the changing of states of bitcells of the first subarray of the array of bitcells of the MRAM from the first state to the second state.

Dependencies are inferred from the claim text.

Magnetic field-assisted memory operation

Life of this patent

Magnetic field-assisted memory operation

Life of this patent

Abstract

Claims25