摘要:
A magnetic memory cell 1 is provided with a magnetic recording layer 10 which is a ferromagnetic layer and a pinned layer 30 connected with the magnetic recording layer 10 through a non-magnetic layer 20. The magnetic recording layer 10 has a magnetization inversion region 13, a first magnetization fixed region 11 and a second magnetization fixed region 12. The magnetization inversion region 13 has a magnetization whose orientation is invertible and overlaps the pinned layer 30. The first magnetization fixed region 11 is connected with a first boundary B1 in the magnetization inversion region 13 and a magnetization orientation is fixed on a first direction. The second magnetization fixed region 12 is connected with a second boundary B2 in magnetization inversion region 13 and a magnetization orientation is fixed on a second direction. The first direction and the second direction are opposite to each other.
摘要:
A memory cell is used which includes a plurality of magneto-resistive elements and a plurality of laminated ferrimagnetic structure substances. The plurality of the magneto-resistive elements are placed corresponding to respective positions where a plurality of first wirings extended in a first direction intersects with a plurality of second wirings extended in a second direction which is substantially perpendicular to the first direction. The plurality of the laminated ferrimagnetic structure substances corresponds to the plurality of the magneto-resistive elements, respectively, is placed to have a distance of a predetermined range from the respective plurality of the magneto-resistive elements, and has a laminated ferrimagnetic structure. The magneto-resistive element includes a free layer having a laminated ferrimagnetic structure, a fixed layer, and a nonmagnetic layer interposed between the free layer and the fixed layer.
摘要:
A semiconductor memory device of the present invention comprises a memory array and a read circuit that reads data of a selected cell. The memory array includes a plurality of memory cells and a reference cell each having a memory element that stores data based on change in resistance value. The read circuit includes: a voltage comparison unit that compares a value corresponding to a sense current from the selected cell with a value corresponding to a reference current from the reference cell; a first switch; and a second switch. Both of the first and second switches are provided at a subsequent stage of a decoder and at a preceding stage of the voltage comparison unit. The second switch circuit controls input of the value corresponding to the sense current to the voltage comparison unit, while the first switch circuit controls input of the value corresponding to the reference current to the voltage comparison unit.
摘要:
A magnetic random access memory of the present invention includes: a plurality of first wirings and a plurality of second wirings extending in a first direction; a plurality of third wirings and a plurality of fourth wirings extending in a second direction; and a plurality of memory cells provided at intersections of the plurality of first wirings and the plurality of third wirings, respectively. Each of the plurality of memory cells includes: a first transistor and a second transistor connected in series between one of the plurality of first wirings and one of the plurality of second wirings and controlled in response to a signal on one of the plurality of third wirings, a first magnetic resistance element having one end connected to a write wiring through which the first transistor and the second transistor are connected, and the other end grounded; and a second magnetic resistance element having one end connected to the write wiring, and the other end connected to the fourth wiring.
摘要:
A semiconductor integrated circuit is provided that can prevent an internal voltage from the voltage generating circuit from varying during a long term. The semiconductor integrated circuit of the present invention includes a voltage generating circuit configured to generate a reference voltage; a function circuit configured to operate by using the reference voltage; a first capacitance connected to a first node between the voltage generating circuit and the function circuit; and a switch provided between the voltage generating circuit and the first node. The switch is in a turned-off state at least for a period during which the function circuit is in an activated state.
摘要:
A magnetic random access memory includes: a first and second wirings, a plurality of third wirings, a plurality of memory cells and a terminating unit. The first and second wirings extend in a Y direction. The plurality of third wirings extends in an X direction. The memory cell is provided correspondingly to an intersection between the first and second wirings and the third wiring. The terminating unit is provided between the plurality of memory cells and connected to the first and second wirings. The memory cell includes transistors and a magnetoresistive element. The transistors are connected in series between the first and second wirings and controlled based on a signal of the third wiring. The magnetoresistive element is connected to a wiring through which the transistors are connected. At a time of a writing operation, when the write current Iw is supplied from one of the first and second wiring to the other through the transistors, the terminating unit grounds the other.
摘要:
By first readout, the current input from a selected cell 13 is converted by a preamplifier 3 and a VCO 4 into pulses of a frequency inversely proportionate to the current value, and the number of the pulses within a preset time interval is counted by a counter 5 so as to be stored in a readout value register 6. A selected cell is then written to one of two storage states, and second readout is then carried out. The storage state of the selected cell is verified by comparing a count value of the counter for the second readout, a count value for the first readout as stored in a readout value register and a reference value stored in a reference value register 7 to one another. By the use of the VCO, the integrating capacitor for the current or reference pulse generating means, so far needed, may be eliminated to assure a small area, low power consumption and fast readout.
摘要:
A semiconductor memory device which uses tunneling magnetoresistive element as memory cells and eliminates the temperature dependencies in a write margin and read margin in such a way as to be able to accurately output a write current at the time of writing the memory cells. The semiconductor memory device is constructed in such a way that main bit lines or main word lines are laid out so as to cross bit lines or word lines perpendicularly, and a main bit line selector or a main word line selector which respectively selects the main bit line or the main word line is arranged outside a memory cell array.
摘要:
An MRAM comprises: a plurality of magnetic memory cells each having a magnetoresistive element; and a magnetic field application section. The magnetic field application section applies an offset adjustment magnetic field in a certain direction to the plurality of magnetic memory cells from outside the plurality of magnetic memory cells. Respective data stored in the plurality of magnetic memory cells become the same when the offset adjustment magnetic field is removed.
摘要:
A magneto-resistance element includes a free layer, a fixed layer and a non-magnetic layer interposed between the free layer and the fixed layer. The free layer has a first magnetic layer, a second magnetic layer, a third magnetic layer, a first non-magnetic layer interposed between the first magnetic layer and the second magnetic layer, and a second non-magnetic layer interposed between the second magnetic layer and the third magnetic layer. The first magnetic layer, the second magnetic layer and the third magnetic layer are coupled such that spontaneous magnetizations have a helical structure.