Semiconductor device
First Claim
1. A semiconductor device comprising:
- a memory array including a plurality of memory cells;
a data encoder which compares read data of a plurality of memory cells selected from the plurality of memory cells with input data, and encodes the input data to form write data; and
a data decoder which decodes the read data.
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Accused Products
Abstract
There is disclosed a write operation of a MRAM in which a current necessary for inverting magnetization of an MTJ element has to be passed through a data line and therefore current consumption is large. The write operation comprises: comparing input data DI with read data GO read from a memory cell array and encoding the input data DI to form write data GI by a data encoder WC; and decoding the read data GO by a data decoder RD to form output data DO. In a nonvolatile semiconductor memory in which the current is passed through the data line to write data into a memory cell, the number of bits to be written during the write operation is reduced, and the current consumption can be reduced. This can realize the MRAM including a low-power highly-integrated memory.
39 Citations
20 Claims
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1. A semiconductor device comprising:
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a memory array including a plurality of memory cells;
a data encoder which compares read data of a plurality of memory cells selected from the plurality of memory cells with input data, and encodes the input data to form write data; and
a data decoder which decodes the read data. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13)
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14. A semiconductor device comprising:
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a memory array including a plurality of memory cells disposed in desired intersections of a plurality of word lines with a plurality of data lines; and
first and second write buffers which drive opposite ends of the data line to pass a write current, wherein each of the plurality of memory cells comprises a magnetoresistive element and transistor, and the first and second write buffers pass the write current, only when the memory cell on the data line is subjected to inverting/writing. - View Dependent Claims (15)
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16. A semiconductor device comprising:
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a memory array comprising a plurality of memory cells disposed in desired intersections of a plurality of word lines with a plurality of data lines; and
a write buffer which drives opposite ends of the data line to pass a write current, wherein each of the plurality of memory cells comprises a phase change resistance element and transistor, and the write buffer drives the data line, only when the memory cell on the data line is subjected to inverting/writing. - View Dependent Claims (17, 18)
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19. A semiconductor device comprising a memory array comprising a plurality of memory cells,
wherein writing into a plurality of memory cells selected from the plurality of memory cells comprises: - an operation of comparing read data from the plurality of selected memory cells with write data inputted from the outside;
an operation determining logic of the write data as a flag bit based on the comparison result so that the number of bits to be inverted is reduced in the read data; and
an operation of writing the write data decoded in accordance with logic of the flag bit and the flag bit into the plurality of selected memory cells. - View Dependent Claims (20)
- an operation of comparing read data from the plurality of selected memory cells with write data inputted from the outside;
Specification