NONVOLATILE MEMORY DEVICE AND METHODS OF PROGRAMMING AND READING THE SAME
First Claim
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1. A read method of a non-volatile memory device, comprising:
- reading an initial threshold voltage value of an index cell from threshold voltage information cells that store information indicating the initial threshold voltage;
reading a current threshold voltage value from the index cell;
comparing the initial threshold voltage value and the current threshold voltage value to calculate a shifted threshold voltage level of the index cell; and
changing a read voltage by the shifted threshold voltage level to read user data using the changed read voltage.
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Abstract
A read method of a non-volatile memory device includes reading an initial threshold voltage value of an index cell from threshold voltage information cells that store information indicating the initial threshold voltage, determining a current threshold voltage value from the index cell, and comparing the initial threshold voltage value and the current threshold voltage value to calculate a shifted threshold voltage level of the index cell. A read voltage is changed by the shifted threshold voltage level to read user data using the changed read voltage.
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20 Claims
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1. A read method of a non-volatile memory device, comprising:
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reading an initial threshold voltage value of an index cell from threshold voltage information cells that store information indicating the initial threshold voltage; reading a current threshold voltage value from the index cell; comparing the initial threshold voltage value and the current threshold voltage value to calculate a shifted threshold voltage level of the index cell; and changing a read voltage by the shifted threshold voltage level to read user data using the changed read voltage. - View Dependent Claims (2, 3, 4, 5, 6, 7)
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8. A program method of a non-volatile memory device, comprising:
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programming user data; programming an index cell with an index bit for monitoring a threshold voltage variation; reading an initial threshold voltage of the index cell; and programming data corresponding to the initial threshold voltage in threshold voltage information cells, wherein the index cell and the threshold voltage information cells are connected to a first word line. - View Dependent Claims (9, 10, 11, 12)
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13. A non-volatile memory device comprising:
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a memory cell array comprising a main area and an index area, the main area comprising main memory cells arranged among a plurality of word lines and a plurality of bit lines for storing user data bits, and the index area comprising index memory cells arranged among the plurality of word lines and a plurality of index bit lines, the index memory cells including threshold voltage information cells and an index cell storing an index bit and providing a threshold voltage variation; a row decoder for selecting one of the plurality of word lines in response to an address; a word line voltage generator for supplying a word line voltage to the selected word line in response to a step code; a page buffer for temporarily storing the user data bits to be programmed in or sensed from the main area, temporarily storing the index bit to be programmed in the index area and data bits corresponding to an initial threshold voltage of the index cell, and temporarily storing the index bit and the data bits corresponding to the initial threshold voltage sensed from the index area via the plurality of index bit lines; and a controller for controlling the word line voltage generator and the page buffer, and generating the step code applied to the word line voltage generator. - View Dependent Claims (14, 15, 16, 17, 18, 19, 20)
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Specification