Nonvolatile memory device comprising one-time-programmable lock bit register
First Claim
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1. A nonvolatile memory device, comprising:
- a variable-resistance memory cell array comprising a memory block that stores protected data;
a register that stores lock state information indicating whether the protected data is changeable, wherein the register comprises a variable-resistance memory cell and an initial value of the lock state information is set to a program protection state; and
a mode controller that changes the protected data stored in the memory block in response to the lock state information,wherein the mode controller causes the register to store program unprotection information in response to a hidden code received from an external source.
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Abstract
A nonvolatile memory device comprises a one-time-programmable (OTP) lock bit register. The nonvolatile memory device comprises a variable-resistance memory cell array comprising an OTP block that store data and a register that stores OTP lock state information indicating whether the data is changeable. The register comprises a variable memory cell. An initial value of the OTP lock state information is set to a program protection state.
33 Citations
11 Claims
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1. A nonvolatile memory device, comprising:
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a variable-resistance memory cell array comprising a memory block that stores protected data; a register that stores lock state information indicating whether the protected data is changeable, wherein the register comprises a variable-resistance memory cell and an initial value of the lock state information is set to a program protection state; and a mode controller that changes the protected data stored in the memory block in response to the lock state information, wherein the mode controller causes the register to store program unprotection information in response to a hidden code received from an external source. - View Dependent Claims (2, 3, 4, 5, 6)
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7. A method of operating a nonvolatile memory device comprising a variable-resistance memory cell array comprising a memory block that stores protected data, and a variable-resistance memory cell that stores lock state information indicating whether the protected data is changeable, the method comprising:
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initializing the variable-resistance memory cell to a program protection state; receiving a security code; in response to the security code, changing the variable-resistance memory cell to a program unprotection state; while the variable-resistance memory cell is in the program unprotection state, programming the memory block; receiving a data protection command; and in response to the protection command, changing the variable-resistance memory cell to the program protection state. - View Dependent Claims (8, 9, 10, 11)
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Specification