Semiconductor memory device and control method of the same
First Claim
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1. A semiconductor memory device, comprising:
- a memory cell array;
a voltage generating circuit;
a memory circuit which stores a reference pulse number of an advance-write voltage of the memory cell array and a parameter; and
a control circuit which controls, when a pulse number of the advance-write voltage that is deterioration information of the memory cell is less than the reference pulse number of the advance-write voltage, the voltage generating circuit in a manner to decrease at least one of an initial value of a write voltage and a step-up width of the write voltage in accordance with the parameter,wherein the control circuit controls the voltage generating circuit by;
writing for obtaining the pulse number of the advance-write voltage;
counting and storing the pulse number; and
feeding back the counted pulse number.
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Abstract
A semiconductor memory device includes a memory cell array, a voltage generating circuit, a memory circuit which stores a reference pulse number of an advance-write voltage of the memory cell array and a parameter, and a control circuit which controls, when a pulse number of the advance-write voltage is less than the reference pulse number of the advance-write voltage, the voltage generating circuit in a manner to decrease at least an initial value of a write voltage and a step-up width of the write voltage in accordance with the parameter.
21 Citations
18 Claims
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1. A semiconductor memory device, comprising:
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a memory cell array; a voltage generating circuit; a memory circuit which stores a reference pulse number of an advance-write voltage of the memory cell array and a parameter; and a control circuit which controls, when a pulse number of the advance-write voltage that is deterioration information of the memory cell is less than the reference pulse number of the advance-write voltage, the voltage generating circuit in a manner to decrease at least one of an initial value of a write voltage and a step-up width of the write voltage in accordance with the parameter, wherein the control circuit controls the voltage generating circuit by; writing for obtaining the pulse number of the advance-write voltage; counting and storing the pulse number; and feeding back the counted pulse number. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9)
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10. A semiconductor memory device capable of storing multi-bit data in one memory cell, comprising:
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a memory cell array in which the memory cell is disposed; a voltage generating circuit; a memory circuit which stores a reference pulse number of an advance-write voltage of the memory cell array and a parameter; and a control circuit which controls, when a pulse number of the advance-write voltage that is deterioration information of the memory cell is less than the reference pulse number of the advance-write voltage, the voltage generating circuit in a manner to decrease at least one of an initial value of a write voltage and a step-up width of the write voltage in accordance with the parameter, wherein the control circuit controls the voltage generating circuit by; writing for obtaining the pulse number of the advance-write voltage; counting and storing the pulse number; and feeding back the counted pulse number. - View Dependent Claims (11, 12, 13, 14, 15, 16)
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17. A control method of a semiconductor memory device including a memory cell array, a voltage generating circuit, a memory circuit which stores a reference pulse number of an advance-write voltage of the memory cell array and a parameter, and a control circuit which controls the voltage generating circuit, the method comprising:
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counting a pulse number of pulses of an advance-write voltage that is deterioration information of the memory cell which is applied to the memory cell array after the erase operation, thereby detecting deterioration information of the memory cell array; changing, when a write operation is executed in the memory cell array, the parameter in a manner to decrease at least one of an initial value of a write voltage and a step-up width of the write voltage in a case where the counted pulse number of the advance-write voltage is less than the reference pulse number of the advance-write voltage; and controlling the voltage generating circuit and executing the write operation by using the changed parameter. - View Dependent Claims (18)
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Specification