Back to results
US 6,611,454 B2Granted
Thin film magnetic memory device writing data of a plurality of bits in parallel
AssigneeMitsubishi Denki Kabushiki Kaisha
InventorHideto Hidaka
Life of this patent
Estimating the term…
Abstract
A memory array is divided into a plurality of memory blocks each having a plurality of bit line pairs. In the memory block selected for a data write operation, first and second selection gates are turned ON so as to couple first and second nodes to the power supply voltage and the ground voltage, respectively. In the data write operation, complementary bit lines of the same bit line pair are electrically coupled to each other through a bit-line coupling transistor. A bit-line current switching portion connects a plurality of bit line pairs in series between the first and second nodes so that the directions of reciprocating-current paths respectively formed in the plurality of bit line pairs correspond to the respective data levels of a plurality of bits.
Claims22
A thin film magnetic memory device capable of writing input data of a plurality of bits in parallel, comprising:
- a memory array including a plurality of magnetic memory cells arranged in rows and columns, wherein
- each of said plurality of magnetic memory cells includes a storage portion having an electric resistance value varying according to a data level that is written according to combination of first and second data write magnetic fields respectively applied by first and second data write currents,
- said memory array is divided into a plurality of memory blocks, one of said plurality of memory blocks being selected in a data write operation, and
- each of said plurality of memory blocks includes
- k first bit lines respectively corresponding to the columns of said plurality of magnetic memory cells, for passing said first data write current therethrough (where k is an integer at least 2),
- a block selection gate for coupling first and second nodes to first and second voltages, respectively, when a corresponding one of said plurality of memory blocks is selected, and
- a first bit-line current switching portion for connecting said k first bit lines in series between said first and second nodes in said data write operation so that said first data write current flows through each of said k first bit lines in a direction corresponding to a respective data level of k-bit input data, said thin film magnetic memory device further comprising:
- a plurality of write word lines respectively corresponding to the rows of said magnetic memory cells, and selectively activated in said data write operation according to a row selection result, for passing said second data write current therethrough.
5 more elements
A thin film magnetic memory device capable of writing input data of a plurality of bits in parallel, comprising:
- a memory array including a plurality of magnetic memory cells arranged in rows and columns, each of said plurality of magnetic memory cells including a storage portion having a resistance value varying according to a data level that is written according to combination of first and second data write magnetic fields respectively applied by first and second data write currents;
- a plurality of first bit lines respectively corresponding to the columns of said plurality of magnetic memory cells, for passing said first data write current therethrough according to a column selection result, each of said first bit lines being divided into h first sub bit lines;
- a plurality of write word lines respectively corresponding to the rows of said magnetic memory cells, and selectively activated in a data write operation according to a row selection result, for passing said second data write current therethrough, said plurality of write word lines being divided into h groups respectively corresponding to said h first sub bit lines, and one of the write word lines being activated in each of said h groups according to said row selection result;
- and
- a bit-line current switching portion provided for every first bit line, each of said bit-line current switching portions coupling the corresponding h first sub bit lines in series between a first node receiving said first data write current to be supplied to a corresponding one of said plurality of first bit lines and a second node receiving said first data write current from the corresponding first bit line, and the coupling of the h first sub bit lines in series between said first and second nodes being conducted so that said first data write current flows through each of the h first sub bit lines of the corresponding first bit line in a direction corresponding to a respective data level of h-bit input data to be written through said corresponding first bit line.
2 more elements
A thin film magnetic memory device capable of writing input data of a plurality of bits in parallel, comprising
- a memory array including:
- a plurality of magnetic memory cells arranged in rows and columns, wherein
- each of said plurality of magnetic memory cells includes a storage portion to which data is written according to a magnetic field applied by a data write current corresponding to the data;
- said memory array further including:
- a plurality of bit lines for passing said data write current therethrough;
- and
- a bit-line current switching portion for connecting selected k bit lines (where k is an integer of at least 2) of said plurality of bit lines in series so as to apply said data write current to each of said k bit lines in a direction corresponding to a respective data level of k-bit input data.
4 more elements
A thin film magnetic memory device comprising:
- a memory array including a plurality of magnetic memory cells arranged in rows and columns,
- each of said plurality of magnetic memory cells including a storage portion to which data is written according to a magnetic field applied by a data write current corresponding to the data;
- a plurality of read select lines provided respectively corresponding to said rows and for selecting said rows in a data read operation;
- and
- a plurality of bit line pairs provided respectively corresponding to said columns, and each including first and second bit lines;
- wherein
- said plurality of magnetic memory cells are arranged such that all of the magnetic memory cells included in a selected row are electrically connected to one of said first and second bit lines in said data read operation.
4 more elements
A thin film magnetic memory device comprising:
- a memory array including a plurality of magnetic memory cells arranged in rows and columns,
- each of said plurality of magnetic memory cells including a storage portion to which data is written according to a magnetic field applied by a data write current corresponding to the data;
- a plurality of bit line pairs provided respectively corresponding to said columns, each including first and second bit lines;
- a bit-line coupling portion provided for each of said bit line pairs, for electrically coupling one end of the corresponding first bit line and one end of the corresponding second bit line to each other at least in a column selected for a data write operation;
- and
- a data write circuit electrically coupled to the first and second bit lines coupled by said bit-line coupling portion in a data write operation, for providing said data write current having a direction corresponding to a level of the data;
- wherein
- each of said plurality of magnetic memory cells is electrically connected to one of said first and second bit lines in each of said rows.
5 more elements
Dependencies are inferred from the claim text.