MEMORY DEVICE AND METHOD FOR DRIVING MEMORY DEVICE
First Claim
1. A memory device comprising:
- a control circuit;
an input-output portion electrically connected to the control circuit;
an input signal line electrically connected to the input-output portion;
an output signal line electrically connected to the input-output portion;
a selection circuit electrically connected to the control circuit;
a selection signal line electrically connected to the selection circuit; and
a memory circuit electrically connected to the input signal line, the output signal line, and the selection signal line, the memory circuit comprising;
a memory cell;
a first switching element electrically connected between the input signal line and the memory cell;
a second switching element electrically connected between the output signal line and the memory cell;
a third switching element electrically connected to the input signal line;
a D/A converter electrically connected between the third switching element and the memory cell;
a fourth switching element electrically connected to the output signal line; and
an A/D converter electrically connected between the fourth switching element and the memory cell.
1 Assignment
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Accused Products
Abstract
A memory device in which one memory cell can operate in both a single-level cell mode and a multi-level cell mode includes a signal transmission path for a multi-level cell mode in which a multi-bit digital signal representing any of three or more states input to the memory circuit is converted by a D/A converter and stored in the memory cell and the stored data is read by converting a signal output from the memory cell into a multi-bit digital signal with an A/D converter and the multi-bit digital signal is output from the memory circuit, and a signal transmission path for a single-level cell mode in which a single-bit digital signal representing any of two states input to the memory circuit is directly stored in the memory cell and the signal stored in the memory cell is directly output from the memory cell.
23 Citations
20 Claims
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1. A memory device comprising:
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a control circuit; an input-output portion electrically connected to the control circuit; an input signal line electrically connected to the input-output portion; an output signal line electrically connected to the input-output portion; a selection circuit electrically connected to the control circuit; a selection signal line electrically connected to the selection circuit; and a memory circuit electrically connected to the input signal line, the output signal line, and the selection signal line, the memory circuit comprising; a memory cell; a first switching element electrically connected between the input signal line and the memory cell; a second switching element electrically connected between the output signal line and the memory cell; a third switching element electrically connected to the input signal line; a D/A converter electrically connected between the third switching element and the memory cell; a fourth switching element electrically connected to the output signal line; and an A/D converter electrically connected between the fourth switching element and the memory cell. - View Dependent Claims (2, 3, 4)
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5. A memory device comprising:
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a memory circuit comprising a first signal transmission path for a single-level cell mode and a second signal transmission path for a multi-level cell mode; a control circuit configured to select whether the memory circuit is used in the single-level cell mode or the multi-level cell mode; an input-output portion configured to output a first signal based on the selection by the control circuit to the memory circuit and configured to be input a second signal from the memory circuit; and a selection circuit configured to determine whether the first signal transmission path or the second signal transmission path is used based on the selection by the control circuit, wherein the first signal transmission path includes a first input path including a first switching element, a first output path including a second switching element, and a memory cell electrically connected between the first input path and the first output path, and wherein the second signal transmission path includes a second input path including a third switching element and a D/A converter, a second output path including a fourth switching element and an A/D converter, and the memory cell electrically connected between the second input path and the second output path. - View Dependent Claims (6, 7, 8, 9, 10, 11)
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12. A method for driving a memory device including a memory circuit, the method comprising the steps of:
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writing one of a single-bit data and a multi-bit data to a memory cell included in the memory circuit according to a selection by a control circuit electrically connected to the memory circuit; and reading the one of the single-bit data and the multi-bit data from the memory cell, wherein the memory circuit includes; a first input path including a first switching element electrically connected to the memory cell; a first output path including a second switching element electrically connected to the memory cell; a second input path including a third switching element and a D/A converter electrically connected between the third switching element and the memory cell; and a second output path including a fourth switching element and an A/D converter electrically connected between the fourth switching element and the memory cell, wherein in the case of writing the single-bit data to the memory cell and reading the single-bit data from the memory cell, the single-bit data is written to the memory cell though the first input path and is read from the memory cell though the first output path, and wherein in the case of writing the multi-bit data to the memory cell and reading the multi-bit data from the memory cell, the multi-bit data is written to the memory cell though the second input path and is read from the memory cell though the second output path. - View Dependent Claims (13, 14, 15)
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16. A method for driving a memory device including a memory circuit, the method comprising the steps of:
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writing a first multi-bit data to a memory cell included in the memory circuit, wherein the first multi-bit data includes a single-bit data and a second multi-bit data; and reading one of the single-bit data and the second multi-bit data from the memory cell, wherein the memory circuit further includes; a first input path including a first switching element electrically connected to the memory cell; a first output path including a second switching element electrically connected to the memory cell; a second input path including a third switching element and a D/A converter electrically connected between the third switching element and the memory cell; and a second output path including a fourth switching element and an A/D converter electrically connected between the fourth switching element and the memory cell, wherein the first multi-bit data is written to the memory cell though the second input path, wherein in the case of reading the single-bit data from the memory cell, the single-bit data is read from the memory cell though the first output path, and wherein in the case of reading the second multi-bit data from the memory cell, the second multi-bit data is read from the memory cell though the second output path. - View Dependent Claims (17, 18, 19, 20)
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Specification