KR100995327B1 - Nonvolatile Memory Device and Driving Method thereof - Google Patents

Abstract

The present invention provides a nonvolatile memory device capable of storing data repeatedly using a plurality of OTP (One Time Programmable) cells and a driving method thereof. To this end, the present invention provides a plurality of data blocks comprising a plurality of OTP cells; And a flag block for storing a flag for identifying validity of data stored in the data block, and a data output unit configured to output data stored in any one of the data blocks according to the flag. To provide.

Nonvolatile Memory Devices, OTP

Description

Nonvolatile memory device and driving method thereof {NONVOLATILE MEMORY DEVICE AND DRIVING METHOD THEREOF}

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to semiconductor design technology, and more particularly, to a nonvolatile memory device having a One Time Programmable (OTP) cell and a driving method thereof.

Nonvolatile memory devices among semiconductor memory devices are used to store initial data of a process or other necessary user data in various electronic devices due to the nonvolatile nature of storing data even without a power source. Such a nonvolatile memory device is classified into a multi-time programmable (hereinafter, referred to as MTP) that can store data several times in the same memory space and an OPT that can be stored only once.

Non-volatile memory devices are used in semiconductor products or other necessary products where product size is important. For this reason, OTP is used rather than MTP, which can be stored many times repeatedly because of the area of the device and the characteristics of electrostatic discharge (ESD). However, OTP can only record the data once, because of its ability to record only once, if it is necessary to store specific data for product production, testing, and functional reasons, it can affect the overall product operation and yield depending on the validity or defect of the device. do.

Therefore, the present invention has been proposed to solve the problems according to the prior art, and has the following objects.

First, it is an object of the present invention to provide a nonvolatile memory device capable of repeatedly storing data using a plurality of OTP cells and a driving method thereof.

Second, another object of the present invention is to provide a nonvolatile memory device and a method of driving the same, which always output valid data even when a defect exists in data stored in an OTP cell.

According to an aspect of the present invention, there is provided a data block including a plurality of one time programmable (OTP) cells, a plurality of flag blocks in which a flag for identifying validity of data stored in the data block is stored; A nonvolatile memory device includes a data output unit configured to output data stored in one of the data blocks according to the flag.

According to another aspect of the present invention, there is provided a method of driving a nonvolatile memory device, the method including: reading a flag of a first flag block among the flag blocks and whether a read flag is a valid flag; Determining, and reading a flag of a next flag block by increasing a block address if the read flag is a valid flag, and storing data in a corresponding data block if the read flag is not a valid flag. Provide a method.

According to still another aspect of the present invention, there is provided a method of driving a nonvolatile memory device, the method including: reading a flag of a first flag block among the flag blocks, and whether the read flag is a valid flag; And determining whether the read flag is a valid flag and outputting data stored in the corresponding data block, and if the read flag is not a valid flag, increasing the block address to read a flag of the next flag block. It provides a driving method.

According to still another aspect of the present invention, there is provided a method of driving a nonvolatile memory device, the method comprising: determining validity of data stored in a selected data block among the data blocks; And updating a flag of a flag block allocated to the selected data block according to the validity of the nonvolatile memory device.

According to the present invention including the above configuration, it is possible to repeatedly store data by using a plurality of OTP cells, and it is possible to always output valid data even if wrong data is stored. Thereby, the yield of a product can be improved.

DETAILED DESCRIPTION Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings so that those skilled in the art may easily implement the technical idea of the present invention. In addition, the parts denoted by the same reference numerals (or reference numerals) throughout the specification represent the same elements.

In the entire description of the specification, when a part has (or includes) a certain component, it means that the component may further include other components, except for the absence of a specially opposed description. . In addition, in the description of the specification, 'data validity' means that data stored in a memory cell, that is, an OTP cell is valid data, and 'having data validity' means that data to be stored is stably OTP. It means stored in the cell. In addition, 'ineffective data' means that the data to be stored is not stably stored in the OTP cell and the data to be stored and the data stored in the OTP cell are not the same.

Example

1 is an equivalent circuit diagram illustrating a nonvolatile memory device according to an embodiment of the present invention.

Referring to FIG. 1, a nonvolatile memory device according to an embodiment of the present invention includes a memory cell array 100. The memory cell array 100 includes a plurality of data blocks DBLK0 to DBLKN including a plurality of OTP cells OTP0 to OTPM, and a flag for identifying validity of data stored in each of the data blocks DBLK0 to DBLKN. Includes a plurality of flag blocks FB0 to FBN stored therein. In addition, the data output unit 130 outputs data stored in any one of the data blocks DBLK0 to DBLKN according to the flag.

One flag block FB0 to FBN is allocated to each of the data blocks DBLK0 to DBLKN. The flag blocks FBO to FBN each store a flag identifying whether the data stored in the data blocks DBLK0 to DBLKN are valid data or invalid data. In other words, a flag corresponding to the validity of data stored in the data blocks DBLK0 to DBLKN is stored. The flag may consist of one OTP cell and store 1-bit. For example, the flag has a form of '0' or '1' in binary, and in the case of 'O', the data is not valid, and in the case of '1', the flag is valid.

In addition, the nonvolatile memory device according to the embodiment of the present invention further includes a data selector 110. The data selector 110 receives a block address for selecting the data blocks DBLK0 to DBLKN including the flag blocks FB0 to FBN, and responds to the write operation signal or the read operation signal in response to the input write operation signal or the read operation signal. Select the data block corresponding to the block address currently input from DBLK0 to DBLKN). In this case, the data selector 110 selects one flag block among the flag blocks FBO to FBN in order or sequentially in response to the write operation signal or the read operation signal, and among the data blocks DBLK0 to DBLKN. Select either data block. Here, 'sequential' means writing or reading data sequentially from 'DBLK0' to 'DBLKN' or 'DBLKN to' DBLK0 '. 'Sequential' means writing or reading data randomly from 'DBLK0' to 'DBLKN'. This operation is performed according to the block address input to the data selector 110. The flag stored in the corresponding flag block and the data stored in the corresponding data block are output to the data output unit 130 through one block address. do.

The data output unit 130 receives a flag from a flag block sequentially selected by the data selector 110 among the flag blocks FB0 to FBN, and determines whether the input flag is a valid flag or an invalid flag. do. Here, 'valid flag' means that the data stored in the data block is valid data. 'Invalid flag' means that the data block is not stored or stored in the data block. Means is not valid data. For example, it is determined whether a flag input from the flag block selected by the data selector 110 is binary '1' or '0'. If the flag is '1', the flag is determined to be a valid flag. If the flag is '0', the flag is determined to be an invalid flag.

In addition, the data output unit 130 receives data output from the data block selected by the data selector 110 in response to a read operation signal among the data blocks DBLK0 to DBLKN, and the received data is valid. Determine whether the data is invalid or invalid. For example, the data outputter 130 compares the data input from the data block selected by the data selector 110 with the reference data, and stores the data in the selected data block when the data input from the selected data block is the same as the reference data. The data is judged to be valid data. In other words, it is determined that the data is valid. In this case, 'reference data' is initial data to be stored in a data block. For example, when the data to be stored in the data block, that is, the reference data is 6-bit data, represented by the binary number '110101', and the data stored in the data block is actually the binary number '100100', the reference data and data Since the data stored in the block are not the same as each other, it is determined that the data stored in the data block is invalid.

In addition, the nonvolatile memory device according to the embodiment of the present invention further includes a data provider 120. The data provider 120 provides data to be stored as a data block selected by the data selector 110 in response to a write operation signal among the data blocks DBLK0 to DBLKN. In addition, the data provider 120 may provide a 1-bit flag corresponding to the binary '0' or '1' to the flag blocks FB0 to FBN according to the determination result of the data output unit 130. For example, as a result of the determination of the data output unit 130, if the data stored in the selected data block is valid data, the data providing unit 120 provides a flag corresponding to the binary number '1', As a result of the determination, when the data stored in the selected data block is not valid data, a flag corresponding to binary '0' is provided.

Hereinafter, a method of driving a nonvolatile memory device according to an embodiment of the present invention will be described.

2 is a flowchart illustrating a write operation of a nonvolatile memory device according to an embodiment of the present invention.

1 and 2, first, the data selector 110 selects the first flag block 'FB0'. The flag of the selected 'FBO' is provided to the data output unit 130 (S21). The data output unit 130 determines whether a flag provided from 'FBO' is a valid flag or an invalid flag (S22). In this case, when the flag is '1', the data output unit 130 determines that the flag is valid, and when the flag is '0', the data output unit 130 determines that the flag is not a valid flag.

If the flag of 'FBO' is a valid flag in step S22, the block address is incremented to search for the flag of the next flag block, that is, 'FB1' (S23). Then, step S21 is repeatedly performed in step S21 according to the increased block address to determine whether the flag of the next flag block 'FB1' is a valid flag or an invalid flag. This flag determination process is sequentially performed until the last flag block 'FBN' until a flag block in which an invalid flag is stored is detected.

If the flag of 'FBO' is not a valid flag in step S22, data to be stored in the data block corresponding to 'FBO', that is, 'DBLK0' is stored (S24). Then, the flag of 'FBO' is updated from '0' to '1'. That is, 'FBO' updates the flag with a valid flag.

3 is a flowchart illustrating a read operation of a nonvolatile memory device according to an exemplary embodiment of the present invention.

1 and 3, first, the data selector 110 selects the first flag block 'FB0'. The flag of the selected 'FBO' is provided to the data output unit 130 (S31). The data output unit 130 determines whether a flag provided from 'FBO' is a valid flag or an invalid flag (S32). In this case, when the flag is '1', the data output unit 130 determines that the flag is valid, and when the flag is '0', the data output unit 130 determines that the flag is not a valid flag.

If the flag of 'FBO' is a valid flag in step S32, the block address is incremented to search for the flag of the next flag block, that is, 'FB1' (S33). Then, step S31 is repeatedly performed in step S31 according to the increased block address to determine whether the flag of the next flag block 'FB1' is a valid flag or an invalid flag. This flag determination process is sequentially performed until the last flag block 'FBN' until a flag block in which an invalid flag is stored is detected.

If the flag stored in the 'FBO' in step S32 is a valid flag, the data output unit 130 outputs the data received from the data block corresponding to the 'FBO' (S34).

4 is a flowchart illustrating a flag updating method in a method of driving a nonvolatile memory device according to an exemplary embodiment of the present invention.

1 and 4, data stored in the selected data block is read (S41).

Next, the validity of the read data is determined by comparing the read data with the reference data (S42). In the validity judgment of the data, if the read data is the same as the basic data, the read data is determined to be valid data, and if not, it is determined as invalid data.

If the data read in step S42 and the reference data are not the same, the block address is increased to select the next data block (S43). Then, step S41 is repeatedly performed in step S41 according to the increased block address to determine whether the data stored in the next data block is valid data or invalid data.

In step S42, the flag of the flag block allocated to the data block selected according to the data validity is updated (S44). If the read data is the same as the reference data, the data is provided to the flag block assigned to this selected data block to update the flag from binary '0' to binary '1'. Otherwise, if the stored data is not valid data, that is, the data is invalid, the previous flag binary '0' is kept as it is.

As described above, although the technical idea of the present invention has been described in detail in the preferred embodiments, it should be noted that the above-described embodiments are for the purpose of description and not for the purpose of limitation. In addition, those skilled in the art will understand that various embodiments are possible through the embodiments of the present invention within the scope of the technical idea of the present invention.

1 is a block diagram illustrating a nonvolatile memory device according to an embodiment of the present invention.

2 is a flowchart illustrating a write operation of a nonvolatile memory device according to an embodiment of the present invention.

3 is a flowchart illustrating a read operation of a nonvolatile memory device according to an embodiment of the present invention.

4 is a flowchart illustrating a flag updating method of a nonvolatile memory device according to an embodiment of the present invention.

<Explanation of symbols for main parts of the drawings>

100: memory cell array

110: data selection unit

120: data provider

130: data output unit

Claims (17)

In a nonvolatile memory device, A plurality of data blocks each consisting of a plurality of One Time Programmable (OTP) cells; A plurality of flag blocks in which flags for identifying validity of data stored in the data block are stored; A data selector which receives a block address and selects the flag block and the data block according to the block address; And And a data output unit for determining whether a flag of the selected flag block is a valid flag. And the data output unit outputs the data stored in the selected data block if it is a valid flag, and if it is not a valid flag, the data selector increases the block address and reads the flag of the next flag block. In a nonvolatile memory device, A plurality of data blocks each consisting of a plurality of One Time Programmable (OTP) cells; A plurality of flag blocks in which flags for identifying validity of data stored in the data block are stored; A data selector which receives a block address and selects the flag block and the data block according to the block address; A data output unit for determining whether the received flag is a valid flag; And And a data provider for providing data to the data block selected by the data selector. And, if the flag is valid, the data selector increases the block address to read a flag of the next flag block, and if the flag is not a valid flag, the data provider stores the data in the selected data block. In a nonvolatile memory device, A plurality of data blocks each consisting of a plurality of One Time Programmable (OTP) cells; A plurality of flag blocks in which flags for identifying validity of data stored in the data block are stored; A data selector which receives a block address and selects the flag block and the data block according to the block address; A data output unit for comparing whether the data is valid data by comparing reference data with data of the selected data block; And And a data provider configured to provide a flag of a flag block allocated to the selected data block according to the validity of the data. The method of claim 3, wherein The data output unit, And when the data stored in the selected data block is the same as the reference data, determining that the data stored in the selected data block has data validity. The method of claim 3, wherein The data providing unit, And a flag corresponding to '1' to the selected flag block when the input data is valid data according to a determination result of the data output unit. The method of claim 5, The data selection unit, The nonvolatile memory device of claim 1, wherein data stored in a data block corresponding to a flag block having a flag of '1' is selected and provided to the data output unit. The method according to claim 1 or 2, The data output unit, The flag is determined to be a valid flag when the flag input from the selected flag is '1', and is determined to be an invalid flag when '0'. The method of claim 7, wherein The flag blocks, Nonvolatile memory devices, each consisting of one time programmable unit (OTP) unit cell. The method according to any one of claims 1 to 3, The data selection unit, A nonvolatile memory device which selects one of the data blocks sequentially or nonsequentially. delete delete delete A method of driving a nonvolatile memory device, comprising: a plurality of data blocks consisting of a plurality of one time programmable cells (OTPs), and a plurality of flag blocks in which flags for identifying validity of data stored in the data blocks are stored; Reading a flag of a first flag block of the flag blocks; Determining whether the read flag is a valid flag; And If the read flag is a valid flag, increases a block address to read a flag of a next flag block, and if the read flag is not a valid flag, storing data in a corresponding data block. A method of driving a nonvolatile memory device, comprising: a plurality of data blocks consisting of a plurality of one time programmable cells (OTPs), and a plurality of flag blocks in which flags for identifying validity of data stored in the data blocks are stored; Reading a flag of a first flag block of the flag blocks; Determining whether the read flag is a valid flag; And Outputting data stored in a corresponding data block if the read flag is a valid flag, and reading a flag of a next flag block by increasing a block address if the read flag is not a valid flag. A method of driving a nonvolatile memory device, comprising: a plurality of data blocks consisting of a plurality of one time programmable cells (OTPs), and a plurality of flag blocks in which flags for identifying validity of data stored in the data blocks are stored; Determining validity of data stored in a selected data block of the data blocks; And Updating a flag of a flag block allocated to the selected data block according to the validity of the data. The method of claim 15, Determining the validity of the data stored in the selected data block, Comparing data stored in the selected data block with reference data; And And determining that the data stored in the selected data block has data validity when the data stored in the selected data block is the same as the reference data. The method of claim 15, Updating a flag of a flag block assigned to the selected data block, And when the data of the selected data block is valid, the flag of the flag block allocated to the selected data block is updated to '1'.

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