KR20150017263A

KR20150017263A - Life alarm method of the data storage device with a memory chip

Info

Publication number: KR20150017263A
Application number: KR1020130093320A
Authority: KR
Inventors: 이동석
Original assignee: 주식회사 바른전자
Priority date: 2013-08-06
Filing date: 2013-08-06
Publication date: 2015-02-16

Abstract

The present invention relates to a data storage device having a memory chip referred to as a 'flash memory' as a storage device, and more particularly to a method for informing whether or not the data storage device can be safely used A memory status information request step of requesting memory status information from a host having a usage limit value of the data storage device to the data storage device, the memory status information requesting a memory status having a rewrite count value, A memory status information providing step of transmitting the memory status information to the host according to a request from the host, and an alarm step of informing the user of the status of the data storage device by referring to the inputted memory status information The technical features And to, when the service life of a data storage device having a flash memory expended there is an effect that it is possible to alert the user. In addition, the data storage device can be replaced at an appropriate time, and the device can be stably used according to the purpose of use of various devices using the data storage device.

Description

[0001] The present invention relates to a method of warning a data storage device having a memory chip,

The present invention relates to a data storage device having a memory chip called a " flash memory " as a storage device, and more particularly, to a method of notifying the safe use of the data storage device.

The data storage device to which the present invention is directed is a conventional data storage device having a memory chip called a 'flash memory'. FIG. 1 shows an example of a data storage device having a flash memory and an example of a host using the same. SD card, micro SD card, UFD (USB Flash Driver), eMMC (embedded Multi Media Card) and SSD (Solid State Driver).

The memory chip is a memory semiconductor having both the advantages of a ROM that stores stored data even when power is turned off, and the advantage of a RAM that can input and output information. The memory chip consumes less power, Volatile data storage means having a characteristic of being able to input and output data in a variety of ways such as the vehicle image recording apparatus, the MP3 player, the smart phone, the digital TV, the digital camcorder, the digital camera, the game machine, It is widely used in digital devices (hosts).

The 'flash memory' is composed of a plurality of cells (floating gate transisters) for storing bit information and is divided into a NOR type and a NAND type according to the arrangement of the cells.

NOR flash memory is a structure in which cells are arranged in a horizontal (parallel) structure. In case of erasing or overwriting data, there is a disadvantage in that random access is impossible and the speed is slow and the capacity can not be increased. However, And is widely used as a memory for program storage of devices such as a smart phone.

The NAND type flash memory has a structure in which cells are arranged in a vertical (serial) configuration, and there is a disadvantage in that random access is not possible when data is read, resulting in a slow reading speed. However, since the writing / erasing speed is fast and the size and capacity can be reduced, And the like.

Since the 'flash memory' is a floating gate transistor storing bit information through the entry and exit of electrons in the floating gate, the cell is deteriorated according to the number of erase operations and the data storage function is lost. do.

Therefore, the data storage device having the 'flash memory' as a storage means has a limitation in the service life due to the limit of the erase count (the number of rewrites) of the flash memory.

In the case of NAND type flash memory, the number of rewritable times (P / E Cycles) is about 100,000 times for SLC (Single Level Cell), about 3,000 to 10,000 times for MLC (Multi Level Cell) TLC (Triple Level Cell) is about 1,000 times.

That is, if the data storage device having the flash memory is used for a long period of time and is used in excess of the rewritable number, it may cause problems such as an error bit increase and bad data storage due to an increase in bad blocks or bad device recognition .

For example, in the case of an SD card (data storage device) installed for storing moving picture data in a video storage device for a vehicle, which is referred to as a 'vehicle black box', since the user can not recognize that the service life of the SD card has expired, The SD card that has reached the end of its useful life is being used without replacement.

As such, the use of an SD card having a shortened life span is likely to cause problems such as poor recording or poor recognition, resulting in a problem of not being able to utilize necessary data (for example, video file).

In addition, in the case of failure to record video (data), most users perceive a problem with the video storage device in the vehicle, but in reality, there are a lot of problems due to the life time of the SD card.

If an 8GB SD card (data storage device) using a general MLC (Multi Level Cell) flash memory having a memory block write frequency of 3K is used in the vehicle black box and a 16 GB data size movie is recorded every day,

The capacity of the SD card can be estimated to be about 2.73 years, which is the capacity (8 GB) × durability (3000 times)} / {data capacity per day (16 GB) × 365 days × WAI (1.5) have.

In other words, if a daily 16GB data recording is performed using an 8GB SD card, the SD card usage life will be exceeded after about 2.73 years, resulting in an increase in the number of error bits and bad blocks, resulting in poor recording or poor memory card recognition do.

As described above, since the user can not know the service life of the data storage device having the flash memory, there is a fatal problem that the user can not recognize the replacement time of the data storage device. Accordingly, (Host) can not be achieved.

In order to fundamentally solve the problem caused by the limitation of the service life of the data storage device having the flash memory as described above, it is necessary to provide a method in which the user can recognize that the service life of the data storage device reaches the limit And to provide the above objects.

It is another object of the present invention to provide a method for stably achieving the purpose of use of various devices using a data storage device by allowing the data storage device to be replaced at an appropriate time.

According to another aspect of the present invention, there is provided a method for warning a user of a data storage device, the data storage device being installed in the data storage device, Requesting memory state information from the host to the data storage device; Providing the memory status information to the host according to a request from the host, the memory status information having a rewrite count value; And an alarm step of informing the user of the status of the data storage device by referring to the memory status information inputted by the host.

The alarming step is performed when the host compares the memory use limit value with a rewrite count value included in the memory status information and the rewrite count value exceeds the memory use limit value. do.

The memory usage limit value is a number of times the cell can be rewritten.

Also, the rewrite count value is an average rewrite count value based on the entire memory size by applying a WAI (Wear-Leveling index) to the rewritten data capacity.

Further, the alarming step may be a message output through a display window provided in the host, or flashing of a warning light.

Further, the host is an image recording apparatus for storing moving images.

The present invention has the effect of alerting the user when the service life of the data storage device having the flash memory has expired through the solution of the above problems.

In addition, the data storage device can be replaced at an appropriate time, and the device can be stably used according to the purpose of use of various devices using the data storage device.

1 shows an example of a data storage device having a flash memory and an example of a host using the same,
2 is a diagram for explaining a concept of a life warning method of a data storage device having a memory chip according to the present invention,
3 is a view for explaining an embodiment in which a life warning method of a data storage device having a memory chip of the present invention is applied to a black box.

The following detailed description of the invention refers to the accompanying drawings, which illustrate, by way of illustration, specific embodiments in which the invention may be practiced. These embodiments are described in sufficient detail to enable those skilled in the art to practice the invention. It should be understood that the various embodiments of the present invention are different, but need not be mutually exclusive. For example, certain features, structures, and characteristics described herein may be implemented in other embodiments without departing from the spirit and scope of the invention in connection with one embodiment. It should also be understood that the position or arrangement of individual components within each disclosed embodiment may be varied without departing from the spirit and scope of the present invention. The following detailed description is, therefore, not to be taken in a limiting sense, and the scope of the invention is to be limited only by the appended claims, along with the full scope of equivalents to which such claims are entitled. In the drawings, like reference numerals refer to the same or similar functions throughout the several views.

The present invention relates to a method for warning a user of a data storage device, the method comprising the steps of requesting memory status information (S10) A memory status information providing step (S20), and an alarm step (S30).

The memory state information requesting step S10 is a step for requesting the memory state information to store data in order to grasp the state of the data storage device 20 installed in the host 10 in the host 10 which is various kinds of digital devices using the data storage device 20. [ And requests the data storage device 20 of the status information of the device 20. [

At this time, the host 10 has a usage limit value of the data storage device 20.

The usage limit value set in the host 10 defined in the present invention means a reference value for determining the service life according to the number of times the data storage device 20 is used.

Therefore, the usage limit value may be various values that are used as a criterion for determining the service life according to the use of the data storage device 20, and may be determined according to the host 10 using the data storage device 20 have.

As described above, the set usage limit value may be various values (information) for determining the service life of the data storage device 20, but may be a number of times the data storage device 20 can rewrite data of the cell provided by the manufacturer .

For example, if the data storage device 20 is a NAND type flash memory, the usage limit value set in the host 10 may be set to 100,000 for the SLC, 3,000 for the MLC, and 1,000 for the TLC, depending on the data storage method of the cell .

The usage limit values described above are based on the number of rewritable NAND type flash memories provided by the manufacturer, and may be changed in the future due to specifications change of the manufacturer.

The memory status information providing step S20 is a step of providing the host 10 with the memory status information requested by the host 10 and the data storage device 20 stores the memory status information having the rewrite number value in the host 10 10).

The memory status information defined in the present invention means that the memory status information of the normal data storage device 20 includes the value of the number of rewrites (information) according to the use of the data storage device 20.

The rewrite frequency information is the number of rewrites of cells constituting the data storage device 20 and is calculated by the controller according to the data recording of the data storage device 20 and is recorded in a predetermined data storage period.

That is, the rewrite count value means the number of times of use of all the cells constituting the data storage device 20 and is compared with the usage limit value set in the host 10 to determine the service life of the data storage device 20 Information.

It is preferable that the rewrite count value is an average rewrite count value based on the entire memory size by applying WAI (Wear-Leveling Index) to the rewritten data capacity.

The average rewrite count value is obtained by applying the uniform usage index (WAI) of the memory blocks due to the limited use of the cells constituting the data storage device 20. For example, when the memory capacity of the data storage device 20 is 8 GB And the data capacity is 16 GB, the conceptually writes 8 GB, erases 8 GB, and rewrites 8 GB, so that it is rewritten once in total.

In other words, conceptually, the number of rewriting of the cell is once, which is an ideal number of cell usage. Actually, the average number of rewrites using WAI is determined.

Therefore, when the WAI is 1.5, the data is 16 GB × 1.5 (WAI) and 24 GB, and the average number of rewrites is twice.

For example, if the data capacity is 72 GB, the ideal number of rewrites is 8, but the average number of rewrites is 108 GB by applying the weight (WAI).

The alarm step S30 informs the user of the status of the data storage device by referring to the memory status information in the host 20 receiving the memory status information from the data storage device 20.

For example, the alarm step S30 may output a warning message or a state information message through a display window provided in the host 10, or may include a warning lamp, and when the life span of the data storage device 20 is exceeded, The warning light blinks so that the user 30 can recognize the replacement timing of the data storage device 20. [

That is, the alarm step S30 provides the status information of the current data storage device 20 from the host 10 to the user 30 so that the user 30 can use the data storage device 20 stably do.

The alarm step S30 performed by the host 10 may provide the user 30 with information that can grasp the status of the data storage device 20 in various forms, And the number of times of rewriting included in the memory status information of the data storage device 20 is compared with the memory usage limit value so that the user 30 is executed only when the rewrite count value exceeds the memory usage limit value, It is desirable to be able to recognize the replacing time of the battery pack 20.

As described above, the present invention is particularly useful in the host 10 in which the writing / erasing of the data storage device 20 is frequently performed, and the host 10 can be used as a video recording device for a vehicle (aka "black box" A camcorder, a digital camera, and the like, and an image recording apparatus for storing moving images.

Hereinafter, the present invention will be described in detail with reference to black boxes as examples.

3 is a view for explaining an embodiment in which a life warning method of a data storage device having a memory chip of the present invention is applied to a black box.

3, the usage limit value of the black box 100 is set to 3,000 based on the MLC type SD card, and the SD card 200, which is a data storage device, The rewrite count value is stored in a specific part (state information space) designated for the purpose of use.

For example, 0 to 311 bits of 0 to 511 bits of the entire state information space are reserved for the manufacturer, and the average rewrite count value (AEC) is stored in the 88 to 103 bit intervals of the area.

When the black box 100 is driven with the MLC type SD card 200 mounted on the black box 100 as described above, the black box 100 recognizes the SD card 200 Enters a data transmission mode, receives an SD card status value received from the SD card 200 in response to the ACMD 13, checks data stored in 88 to 108 bits from the information included in the received SD card status value And extracts the average rewrite count value (AEC).

Then, if the average rewrite count value is smaller than the usage limit value, video recording is started according to CMD24 or 25, and the average rewrite count value (AEC) is compared with the average rewrite count value The alarm unit 110 of the black box 100 is driven to output a warning message informing the user 30 that the service life of the SD card 200 is completed .

While the present invention has been described in connection with what is presently considered to be practical exemplary embodiments, it is to be understood that the invention is not limited to the disclosed embodiments, but, on the contrary, And such variations and modifications are intended to fall within the scope of the appended claims.

10: Host
20: Data storage device
30: User
100: Black box
110:
200: MLC SD card

Claims

A method of warning a life of a data storage device,
A memory status information request step of requesting memory status information from the host having the usage limit value of the data storage device to the data storage device;
Providing the memory status information to the host according to a request from the host, the memory status information having a rewrite count value; And
And an alarm step of informing the user of the status of the data storage device by referring to the memory state information inputted by the host.

2. The method of claim 1,
Comparing the memory use limit value with a rewrite count value included in the memory status information and performing the rewrite count value when the rewrite count value exceeds the memory use limit value. How to warn the life of the device.

2. The method of claim 1, wherein the memory usage limit value
And the number of rewritable times of the data of the cell is equal to the number of rewritable times of the data of the cell.

The method of claim 1, wherein the rewrite count value
(WAI) is applied to a rewritten data capacity, and an average rewrite count value based on the total memory size is applied to the rewritten data capacity.

2. The method of claim 1,
And a message output via a display window provided in the host or flashing of a warning light.

The method of claim 1, wherein the host
Wherein the video memory device is a video recording device for storing moving pictures.