MRAM and access method thereof
AssigneeInternational Business Machines Corporation
InventorsToshio Sunaga, Hisatada Miyatake, Koji Kitamura, Hideo Asano, Kohki Noda, Hiroshi Umezaki
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Abstract
A magnetic random access memory (MRAM) circuit block and access method thereof are disclosed herein which includes a circuit for sensing a data write current passing through a bitline 32 and, for generating a stop signal for stopping a data write current supply to the bitline 32 and a write wordline 30 after data is written in an magnetic tunnel junction (MTJ) element 44. Further, when data to be written to the storage element is the same as the data already stored therein, no write current is supplied to the write wordline 30, thereby saving power.
Claims11
A magnetic random access memory circuit block, comprising:
- a memory array in which a plurality of wordlines and a plurality of bitlines are provided in matrix form and a memory element is provided at intersections of the wordlines and the bitlines, said memory elements including at least a ferromagnetic layer having a magnetization direction determined by the orientation of a magnetic field generated by an electric current passing through a respective bitline coupled thereto;
- a read wordline driver for applying a read voltage to a wordline;
- a write wordline driver for providing a write current onto said wordline;
- a bitline driver for providing a write current onto a bitline;
- a sense amplifier for sensing and amplifying data in a memory element;
- an input/output pad for inputting and outputting data;
- a module for sensing a data write current passing through said bitline;
- and
- a module for generating a stop signal for stopping the supply of the data write current to said bitline and said wordline after data is written in said memory element.
Within a magnetic random access memory circuit block comprising:
- a memory array in which a plurality of wordlines and a plurality of bitlines are provided in matrix form and a memory element is provided at intersections of the worduines and the bitlines, said memory elements including at least a ferromagnetic layer having a magnetization direction determined by the orientation of a magnetic field generated by an electric current passing through a respective bitline coupled to said memory element;
- a read wordline driver for applying a read voltage to a wordline;
- a write wordline driver for providing a write current onto said wordline;
- a bitline driver for providing a write current onto a bitline;
- a sense amplifier for sensing sense and amplifying data in a memory element;
- an input/ouput pad for inputting and outputting data;
- a module for sensing a data write current passing through said bitline;
- and
- a module for generating a stop signal for stopping the supply of the data write current to said bitline and said word line after data is written in said memory element,
- a data access method comprising the steps of:
- sensing current passing through said bitline for writing data in said memory element;
- and
- generating a stop signal for stopping the data write current provided onto said wordline and said bitline after a change in said current is detected at the step of sensing said current.
Dependencies are inferred from the claim text.