A write protection circuit of non-volatile memory which can prevent rewriting

Abstract

The invention belongs to the technical field of the semiconductor memory, and particularly relates to a nonvolatile memory write protection circuit capable of avoiding rewriting. The write protection circuit structure comprises a storage bit, a data control logic module, two column selection transistors, two write access control transistors, two preread control transistors, a current source, a comparator, a latch, a write driving circuit and a write control signal generation circuit, wherein the storage bit is constructed by two units; the data control logic module is used for deciding to open a write access of a left unit or a right unit of the two units according to data to be written; the two column selection transistors are controlled by the same column selection signal; the grid electrodes of the two write access control transistors are independently controlled by a write control signal; the grid electrodes of the preread control transistors are independently controlled by a read control signal; and the write control signal generation circuit inputs a write enable signal and outputs a preread control signal and a write control signal. The invention also puts forwards a write operation flow which aims at a one-time programming memory which constructs the storage bit on the basis of double storage cells, can avoid malicious or unintentional rewriting damage and provides a high-safety storage scheme for sensitive data.

Description

Technical field [0001] The present invention belongs to the technical field of semiconductor memory, and specifically relates to a non-volatile memory write protection circuit, and more particularly to a write protection circuit capable of preventing tampering for one-time programming of non-volatile memory. Background technique [0002] In the information age, while information technology provides convenience to people, it also brings a serious problem, that is, information security, especially the security of sensitive data. The safe storage of sensitive data is the key to ensuring security. [0003] The semiconductor memory uses a data combination of 0 or 1 to store information, and each memory device unit constituting the mass memory can store one data (0 or 1). Generally, it is judged whether the data of the memory continues to be stored in the memory after a power failure. The memory can be divided into a volatile memory and a non-volatile memory, and the data of the non-vola...

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Problems solved by technology

[0010] However, if the opposite data is maliciously or unintentionally written to the programmed memory bit again, the content of the memory bit will be destroyed

For example, if the storage bit 204 has been programmed to 1, that is, the left storage unit is programmed to be in a conductive state, and the right storage unit is kept in a non-conductive state. The cell is programmed to be in the conduction state, and the left memory cell is also in the conduction state, and the data of this storage bit 204 will be destroyed and become an invalid bit

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