JPH087587A - MEMORY CONTROL PROCESSING DEVICE AND MEMORY ERASE LIMIT DETECTION METHOD IN THE DEVICE - Google Patents

Abstract

(57) [Summary] [Purpose] When erasing a memory with a limited number of erases,
(EN) A memory control processing device capable of issuing a warning to a user when the erasure limit is exceeded and improving the reliability of a device using a memory, and a memory erasure limit detection method in the same. [Structure] A storage unit 23 for storing the number of erasures (n) of the memory 1 and a preset erasure limit number (N) of the memory 1, and an output unit 25 for issuing a warning when n> N.
When the memory 1 is erased, the control unit 22 updates the erase count in the storage unit 23 by adding 1 and determines whether the updated erase count exceeds the erase limit count.
A memory control processing device, which is a control unit for instructing the output unit to output a warning when the updated erase count exceeds the erase limit count, and a memory erase limit detection method in the memory control processor.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a memory control processing device for reading from, erasing from, and writing to a memory and a method for detecting an erasing limit of a memory in the memory control processing device. The present invention relates to a memory control processing device capable of issuing a warning to a user when erasing exceeds an erasing limit and improving the reliability of a device using a memory, and a method for detecting the erasing limit of a memory in the device.

[0002]

2. Description of the Related Art EEPROM (Electrically Erasable)
Programmable Read Only Memory) and flash memory are erasable / writable memories, and their contents do not change like RAM even when the power is off or when an erroneous program is executed. It is widely used as an inexpensive and compact system that can be configured.

For example, a memory cell of a floating gate type EEPROM called FLOTOX has an MO having a floating gate (FG) electrically insulated from the surroundings in addition to a normal gate (control gate, CG).
It consists of S-transistors. The oxide film between FG and drain is thinly formed to about 100 Å,
When a voltage (+) sufficiently higher than that of the drain is applied to CG, electrons enter the FG from the drain and are erased. On the contrary, if the polarity of the applied voltage is changed, the electrons contained in the FG escape to the drain and writing is performed.

When erasing / writing is repeated in the EEPROM, the insulation between the floating gate and the drain deteriorates and the EEPROM is destroyed. In general, E
EPROM and flash memory can be erased 100 times
It is about 0 to 10000 times and can be used in many cases without considering the erase count.

[0005]

However, in the above-mentioned device using the EEPROM and the flash memory, there is no means for notifying the erasure limit to the outside, so that the user cannot know the erasure limit and the erasure frequency is If the frequency is high, or if the frequency of erasure is low (for example, twice / day) and used for a long period of time (for example, 10 years), the erasure limit may be exceeded and the reliability of the device may be reduced. There was a problem that it would end up.

The present invention has been made in view of the above circumstances, and when erasing a memory having a limited number of erasures, a warning is given to the user when the erasure limit is exceeded, and the reliability of the device using the memory is relieved. It is an object of the present invention to provide a memory control processing device and a method for detecting the erase limit of a memory in the memory control processing device.

[0007]

The invention according to claim 1 for solving the above-mentioned problems of the prior art is a memory control processing apparatus having a control unit for performing a memory erasing operation. A storage unit that stores a preset erase limit number of the memory and an output unit that issues a warning when the erase number exceeds the erase limit number are provided, and the control unit erases the memory. When updating, the erase count in the storage unit is updated by adding 1 to determine whether the updated erase count exceeds the erase limit count, and the updated erase count exceeds the erase limit count. In this case, the control unit is configured to instruct the output unit to output a warning.

According to a second aspect of the present invention for solving the problems of the conventional example, in the method for detecting the erase limit of the memory in the memory control processing device according to the first aspect, when the control unit erases the memory. Is updated by adding 1 to the erase count stored in the storage unit, and it is determined whether the updated erase count exceeds the erase limit count stored in advance in the storage unit. Is instructed to output a warning to the output unit when the erase limit number is exceeded.

According to a third aspect of the present invention for solving the above-mentioned problems of the conventional example, in the method of detecting the erase limit of the memory in the memory control processing device according to the first aspect, before the control unit erases the memory. In addition, the erase count stored in a specific area of the memory is read and stored in the storage unit, and after the memory is erased, the erase count stored in the storage unit is updated by adding 1 The erase count is stored in the specific area of the memory, and it is determined whether the updated erase count exceeds an erase limit count stored in advance in the storage unit. When the number of times is exceeded, the output unit is instructed to output a warning.

[0010]

According to the invention described in claim 1, in a memory control processing device having a control unit for performing a memory erasing operation, a memory unit for storing the number of times of erasing the memory and a preset erasing limit number, An output unit is provided for issuing a warning when the erase count exceeds the erase limit count, and when the control unit performs a memory erase operation, the erase count in the storage unit is set to 1
The control unit that determines whether or not the updated erase count exceeds the erase limit count, and instructs the output unit to output a warning when the updated erase count exceeds the erase limit count. Since it is a memory control processing device that is, it is possible to manage the number of times the memory is erased in the storage unit, and when the number of erases exceeds the erase limit number, the output unit can issue a warning to the outside, The reliability of the device using the erasable memory can be improved.

According to the second aspect of the present invention, the control section includes:
When erasing the memory, the erase count stored in the storage unit is updated by adding 1 to determine whether the updated erase count exceeds the erase limit count stored in advance in the storage unit, The method according to claim 1, wherein a warning is output to the output unit when the updated erase count exceeds the erase limit count, and the memory erase count detection method stores the memory erase count. It can be managed inside the unit, and when the number of erase times exceeds the erase limit number, the output unit can issue a warning to the outside, and the reliability of the device using the erasable memory can be improved. it can.

According to the third aspect of the present invention, the control section includes:
Before erasing the memory, read the number of erasures stored in a specific area of the memory and store it in the memory,
After the memory is erased, the erase count stored in the storage unit is updated by adding 1, and the updated erase count is stored in a specific area of the memory, and the updated erase count is stored in advance in the storage unit. Judge whether or not the limit number of times is exceeded,
The method according to claim 1, wherein a warning is output to the output unit when the updated erase count exceeds the erase limit count. Memory that can be stored by itself and that can be removed from the memory control processor, or can detect whether the number of erases exceeds the erase limit for many memories, and the reliability of the device using the erasable memory Can be improved.

[0013]

DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described with reference to the drawings. FIG. 1 is a configuration block diagram of a memory control processing device according to an embodiment of the present invention. The memory control processing device of the present embodiment counts the number of times of erasing of the memory connected to this device, and issues a warning to the user when erasing exceeds the preset erasing limit value.

As shown in FIG. 1, the memory control processing device 2 of this embodiment is connected to an erasable memory 1 such as an EEPROM or a flash memory, and an input section 21 for inputting an erasing instruction and the like. Writing to memory 1,
Control unit 22 for erasing and reading from the memory 1
A storage unit 23 that stores the number of times of erasing of the memory 1, an output unit 25 that notifies the user that the number of times of erasing has exceeded a limit value by a buzzer, an LED, etc., and a signal from the control unit 22 that is output by the output unit 25. And an output interface 24 for sending to the.

Next, each component will be specifically described with reference to FIG. The storage unit 23 is a device having a function of retaining stored contents even when the power is off. As the storage unit 23, an FDD (floppy disk drive), an HDD (hard disk drive), an SRAM with a battery backup function, or the like is used. be able to.

The storage unit 23 has an erase limit storage area 23a for storing the erase limit (N) of the memory 1,
There is an erase count storage area 23b for storing the actual erase count (n) of the memory 1, and an erase limit storage area 23a.
The erasure limit (N) of the memory 1 set in advance is stored as an appropriate number of times the memory 1 can be erased.

The controller 22 updates the erase count in the erase count storage area 23b by adding 1 every time the memory 1 is erased. As a result, the latest erase count is always stored and the erase count of the memory 1 is managed.

After erasing the memory 1, the controller 22 compares the updated erase count (n) with the erase limit (N) stored in the erase limit storage area 23a,
When the number of erases exceeds the erase limit, that is, when n> N, a warning signal is output to the output interface 24.

The output interface 24 receives a warning signal from the control unit 22, converts it into a signal suitable for the output unit 25, and sends it out. When the output unit 25 is an LED,
The warning signal from the control unit 22 is converted into a signal instructing lighting of the LED, and when the output unit 25 is a buzzer, it is converted into a signal instructing generation of a buzzer sound. As the output interface 24, an output port, a serial interface, a parallel interface, or the like is used. Serial interface as the output interface 24,
When the parallel interface is used, the output unit 25
A data display terminal or a printer can be used as.

Next, a method of detecting the erase limit of the memory in the memory control processing device of this embodiment will be described with reference to FIG. FIG. 2 is a flow chart showing the processing of the control unit 22 in the method for detecting the erase limit of the memory of this embodiment. As shown in FIG. 2, first, when an instruction of “erase” is input from the input unit 21 (202), the control unit 22
Erases the memory 1 (204), reads the erase count n from the erase count storage area 23b of the storage unit 23 (206), and updates n by n + 1 (208). Then, the updated n is stored in the erase count storage area 23b (210).

Next, the erasure limit storage area 2 of the storage unit 23
The erase limit N is read from 3a (212), it is judged whether n> N (214), and if n ≦ N, the process is terminated. If n> N, a warning signal is sent to the output interface 24 (216). In this way, the processing in the control unit 22 is performed.

The output interface 24 receives the warning signal from the control unit 22, converts it into a signal suitable for the output unit 25, and outputs the signal to the output unit 25. Then, the output unit 25 notifies the user that the number of times of erasing the memory 1 has exceeded the limit and issues a warning by a method such as lighting an LED or generating a buzzer sound. In this way, the method for detecting the erase limit of the memory of this embodiment is performed.

According to the memory control processor of the present embodiment and the method of detecting the erase limit of the memory therein, the EEP
Every time a storage element such as a ROM or a flash memory having a limited erase count is erased, the control unit 22 stores the erase count (n) in the storage unit 23, where n is a previously stored erase limit (N). ) Is exceeded and a warning signal is sent to the output section 25 via the output interface 24 when it exceeds, so that if the number of erases in the memory 1 exceeds the erase limit. Can output a warning from the output unit 25 to the outside, and has the effect of improving the reliability of a device using an erasable memory such as an EEPROM or a flash memory.

In particular, the method for detecting the erase limit of the memory according to the present embodiment is not limited to the case where the number of the memories 1 is small or the structure in which the memories 1 can be removed from the memory control processor 2.
This method is effective when it is fixed to the memory control processing device 2.

Next, a method of detecting the erase limit of a memory according to another embodiment of the present invention will be described. The configuration of the memory control processing device 2 used in another embodiment is the same as that of the memory control processing device of this embodiment shown in FIG. A method of detecting the erase limit of a memory according to another embodiment is such that a specific area for storing the erase count is provided in the memory 1, and the erase count of the specific area is rewritten each time the erase is performed to determine the erase count of itself. This is a method of storing. This method is effective when the number of memories 1 connected to the memory control processing device 2 is large or when the memory 1 can be removed from the memory processing device 2.

Next, a method of detecting the erase limit of the memory of another embodiment will be concretely described with reference to FIG. FIG.
FIG. 8 is a flow chart showing a method for detecting the erase limit of a memory according to another embodiment. As shown in FIG. 3, the input unit 21
When the "erase" instruction is input from (302), the control unit 22 reads the erase count n from a specific area of the memory 1 (304) and stores n in the erase count storage area 23b of the storage unit 23. (306). Then, the memory 1 is erased (308).

Next, n is updated to n + 1 (310), and the updated erase count n is written in a specific area of the memory 1 (312). Further, the erase count n is written in the erase count storage area 23b of the storage unit 23 (314), and the storage unit 23
The erase limit N is read from (316). And n> N
It is determined whether or not (318), and if n ≦ N, the process is terminated.

On the other hand, when n> N in the process 318 and the number of erases exceeds the erase limit, a warning signal is sent to the output interface 24 (320). Then, similarly to the first embodiment, the output unit 25 notifies the user that the number of times of erasing has exceeded the limit due to lighting of the LED or generation of a buzzer sound.

According to another embodiment, a specific area for storing the number of times of erasing of the memory 1 is provided inside the memory 1, and when erasing the memory 1, the control unit 22 controls the area from the specific area of the memory 1. The erase count is read and stored in the storage unit 23, and after the erase, the erase count is incremented by 1 and updated, and the updated erase count n is written in a specific area of the memory 1. It can be stored in itself and can detect whether the number of times of erasing exceeds the erasing limit for removable memory or a large number of memories, and improve the reliability of a device using EEPROM or flash memory. There is an effect that can be done.

The warning method is changed depending on whether the erase count n approaches the erase limit or exceeds the erase limit.
It is also possible to provide more detailed information to the user.
In this case, when the difference (N−n) between the erase limit and the erase count is within a certain value (for example, N−n ≦ 100), the first warning, and when the erase count exceeds the erase limit (n> The second warning is issued to N). For example, when an LED is used as the output unit 25, a yellow LED is turned on when approaching, and a red LED is approached when approaching.
It is conceivable that, for example, a light is emitted, or the output section 25 using a buzzer sounds at a low volume when approaching, and at a high volume when the limit is exceeded.

[0031]

According to the first aspect of the present invention, in a memory control processing device having a control unit for performing a memory erasing operation, a storage unit for storing the number of times of erasing the memory and a preset erasing limit number. And an output unit for issuing a warning when the erase count exceeds the erase limit count, and when the control unit performs the memory erase operation, it is updated by adding 1 to the erase count in the storage unit. The memory control processing device is a control unit that determines whether or not the erase count exceeds the erase limit count, and instructs the output unit to output a warning when the updated erase count exceeds the erase limit count. Therefore, the number of times the memory is erased can be managed in the storage unit, and when the number of erases exceeds the erase limit number, the output unit can issue a warning to the outside. There is an effect that it is possible to improve the reliability.

According to the second aspect of the present invention, the control section comprises:
When erasing the memory, the erase count stored in the storage unit is updated by adding 1 to determine whether the updated erase count exceeds the erase limit count stored in advance in the storage unit, The method according to claim 1, wherein a warning is output to the output unit when the updated erase count exceeds the erase limit count, and the memory erase count detection method stores the memory erase count. It can be managed inside the unit, and when the number of erase times exceeds the erase limit number, the output unit can issue a warning to the outside, and the reliability of the device using the erasable memory can be improved. There is an effect that can be done.

According to the third aspect of the present invention, the control section includes:
Before erasing the memory, read the number of erasures stored in a specific area of the memory and store it in the memory,
After the memory is erased, the erase count stored in the storage unit is updated by adding 1, and the updated erase count is stored in a specific area of the memory, and the updated erase count is stored in advance in the storage unit. Judge whether or not the limit number of times is exceeded,
The method according to claim 1, wherein a warning is output to the output unit when the updated erase count exceeds the erase limit count. Memory that can be stored by itself and that can be removed from the memory control processor, or can detect whether the number of erases exceeds the erase limit for many memories, and the reliability of the device using the erasable memory There is an effect that can improve.

[Brief description of drawings]

FIG. 1 is a configuration block diagram of a memory control processing device according to an embodiment of the present invention.

FIG. 2 is a flow chart diagram showing a memory erase limit detection method of the present embodiment.

FIG. 3 is a flowchart showing a method of detecting an erase limit of a memory according to another embodiment.

[Explanation of symbols]

1 ... Memory, 2 ... Memory control processor, 21 ...
Input unit, 22 ... Control unit, 23 ... Storage unit, 24 ... Output interface, 25 ... Output unit

Claims (3)

[Claims] 1. A memory control processing device having a control unit for performing a memory erasing operation, and a memory unit for storing the number of times of erasing of the memory and a preset erasing limit number of the memory, An output unit that issues a warning when the erase limit count is exceeded, and when the control unit performs the erase operation of the memory, the erase count in the storage unit is updated by adding 1 and the updated erase is performed. The control unit determines whether or not the number of erases exceeds the erase limit number, and instructs the output unit to output a warning when the updated number of erases exceeds the erase limit number. Memory control processor. 2. When the control unit erases the memory,
Update by adding 1 to the erase count stored in the memory,
It is determined whether or not the updated erase count exceeds the erase limit count stored in advance in the storage unit, and when the updated erase count exceeds the erase limit count, a warning is output to the output unit. The method according to claim 1, wherein an instruction is issued to the memory control processor. 3. The control unit, before erasing the memory,
The erase count stored in a specific area of the memory is read and stored in the storage unit. After the memory is erased, the erase count stored in the storage unit is updated by adding 1 to the updated erase count. Is stored in the specific area of the memory, and it is determined whether the updated erase count exceeds the erase limit count stored in advance in the storage unit, and the updated erase count is equal to the erase limit count. 2. The method for detecting the erasing limit of the memory in the memory control processing device according to claim 1, wherein the output unit is instructed to output a warning when it exceeds the limit.