KR910002131B1 - Portable electronics - Google Patents

Abstract

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Description

Portable electronics

1 is an external perspective view of an IC card which is a portable electronic device according to an embodiment of the present invention.

2 is a schematic block diagram showing an example of the electric circuit configuration of the IC card shown in FIG.

FIG. 3 is a diagram showing the configuration of the data memory shown in FIG.

4 is an external perspective view showing the card handling unit of the IC card shown in FIG.

FIG. 5 is a schematic block diagram showing an example of the circuit configuration of the card handler shown in FIG.

6 is a diagram showing the format of a text exchanged between an IC card and a card handler.

FIG. 7 is a diagram showing a bit structure of identification data shown in FIG. 6. FIG.

8 is a cross-sectional view showing an example of the configuration of the IC card reading / recording unit.

9 is a schematic block diagram showing an example of a circuit configuration of an IC card read / write unit.

10 (a) to 10 (c) are flowcharts for explaining the operation of one embodiment of the present invention.

11 is a functional block diagram of an IC card according to another embodiment of the present invention.

12 is a block diagram showing a configuration of an IC chip according to another embodiment of the present invention.

FIG. 13 is a memory map of the data memory shown in FIG.

14 is a flow chart for explaining the operation of the supervisor.

15A and 15B show examples of the format of command data.

FIG. 16 is a flowchart for explaining an operation of cryptography.

Fig. 17 is a diagram showing an example of the format of the command data for cryptographic control.

* Explanation of symbols for main parts of the drawings

1: IC card 2: Connector

2a to 2h: Each terminal 3: Central processing unit (CPU)

4: Data memory 5: Interface circuit

6: RAM 4a-4g: recording area

10: IC card handling unit 11: Central processing unit (CPU)

12: keyboard 13: CRT display device

14: ROM 15: RAM

16: printer 17: floppy disk device

18: floppy disk insertion slot 19: floppy disk

20: IC card read / record 21: Card insertion opening

22: cable 31: return path

32: Return Roller 33: Return Guide

34: read / record 51: central processing unit (CPU)

52: ROM 53: RAM

117: read / record 119: password setting / password control

121: encryption / decryption unit 123: supervisor

125: central processing unit (CPU) 127: data memory

129: program memory 131: connector

145: control function code 147: index data

149: control data

[Industrial use]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a portable electronic device called a IC card, for example, in which IC chips such as a central processing unit (CPU) and data memory are incorporated.

[Traditional Technology and Problems]

Recently, IC cards have been developed and put into practical use as memory cards that record data. These IC cards have integrated IC chips such as a central processing unit and a data memory including a control program and a PROM in which data is recorded. . In addition, the terminals of the CPU and the surface of the card are connected to each other so that data input / output with the outside is executed through the terminals, and data writing and reading to the data memory is executed under the control of the CPU.

However, such an IC card has an effective usage limit determined according to the field of use or purpose of use. The effective usage limit includes, for example, the date of use (expiration date) when the IC card is used as a commuter pass or a credit card. The usage amount when the card is used as a cash card (cash card), a credit card, a telephone card, or the like, and a recording limit capacity of the IC card memory.

However, the above-mentioned effective usage limit can be determined from the external device side by reading the date data, the current recording capacity or the accumulated value in the IC card. For this reason, various data recorded in the IC card can be easily referred from the outside, which causes problems in terms of confidentiality protection.

In addition, a banking system using an IC card with an IC chip is withdrawn. Data used for matching personal identification information in a transaction is stored in magnetic stripes on the surface of the magnetic card. For this reason, there is a possibility of forgery and forgery. However, in the IC card, since the data for inquiry is stored inside the card, the data cannot be referred from the outside. Then, the inquiry between the personal identification information input by the user and the stored verification data is performed inside the card, and only the verification result is output from the IC card. Here, if the verification result of the personal identification information and the verification data does not match, the number of discrepancies is counted. If the number exceeds the predetermined number, the subsequent inquiry is not performed to secure the data in the IC card. It will raise the castle.

However, the comparison between the number of discrepancies and a predetermined number of times is performed in the IC card. However, if the predetermined number of times is fixed in the control program, it is possible to cope with an application such as setting the upper limit of the number of mismatches to another value. There will be no. In particular, since the control program is stored in a mask ROM or the like so that program reading is impossible, it is necessary to produce an IC card in which a program corresponding to each application is stored. Therefore, it is unsuitable for mass production of IC cards. In addition, when the upper limit value of the number of discrepancies is stored in the data memory of the IC card, if the general user can store the data, the security of the data in the IC card is deteriorated.

[Purpose of invention]

The present invention has been invented in view of the above circumstances, and it is not possible to easily refer to the data stored in the IC card from the outside, and to carry the upper limit value of the query mismatch number corresponding to various applications. When an electronic device is initialized, it can be freely set so that one type of portable electronic device can be used to match each application with a different number of inquiries, and once it is initialized, no further changes can be made. It is an object of the present invention to provide a portable electronic device capable of maintaining security as well.

[Configuration of Invention]

A portable electronic device according to the present invention for achieving the above object includes a control central processing unit, a limit data storage area for storing limit data indicating an effective usage limit, and a data storage area for storing data to be processed. And a memory means, wherein the central processing unit compares the limit data contained in the specialized data sent from the host system connected to the portable electronic device with the limit data stored in the memory means. It is configured to determine whether the apparatus is usable and to output the determination result.

EXAMPLE

Hereinafter, embodiments of the present invention will be described with reference to the drawings.

1 is an external perspective view of an IC card according to an embodiment of the present invention, where reference numeral 1 is an IC card as a portable medium. A connector portion 2 is provided on the surface of the IC card 1, for example, which is composed of a plurality of terminals 2a to 2h, of which terminals 2a are power supply voltages (+ 5V) used during operation. The terminal 2b is for grounding, the terminal 2c is for a clock signal, the terminal 2d is for a reset signal, the terminals 2e to 2g are for data input and output, and the terminal 2h is for a power supply voltage (+ 2V) used for writing.

Inside the IC card 1, as shown in FIG. 2, a control central processing unit 3 (CPU), a data memory 4 composed of an EEPROM or a PROM in which control programs and data are recorded, and an interface. It consists of a circuit 5 and a RAM 6 for data processing which stores a telegram supplied from a terminal device to be described later. Each circuit portion described above is composed of an IC chip and is provided on one substrate, and the interface circuit 5 and the connection portion 2 are connected by wiring.

As shown in Fig. 3, the data memory 4 stores limit data storage areas 4a to 4f in which various limit data as effective usage limits are stored in advance when the card is manufactured or issued. It consists of a data storage area 4g, wherein the limit data storage areas 4a to 4f each have a time data limit value storage area 4a in which time data such as year, month, date, and time are stored as the limit values of the time limit. Time data warning value storage area 4b in which time data such as year, month, date and time as warning values (values near the limit value) are stored, and storage capacity limit value storage area 4c in which the last address value as the limit value of the storage capacity limit are stored. Limit of the storage capacity limit warning value storage area 4d and recording accumulation limit in which a predetermined address value as a warning value (value near the limit value) of the storage capacity limit is stored; An accumulation limit value storage area 4e in which an accumulation value as a value is stored, and an accumulation limit warning value storage area 4f in which an accumulation value as a warning value (a value close to an limit value) of a recording accumulation limit is stored.

4 and 5 show the configuration of the IC card handling unit 10 as a terminal device according to the present invention, where reference numeral 11 is a central processing unit (CPU) for controlling the whole, and 12 is for inputting data. A keyboard, 13 is a CRT display device, 14 is a ROM in which a control program is stored, 15 is a RAM in which data is stored, 16 is a printer which prints various kinds of print data, 17 is inserted from a floppy disk insertion hole 18. The floppy disk device for storing and reproducing data to and from the floppy disk 19, 20 reads data from the data storage area 4g in the memory 4 with respect to the IC card 1 inserted from the card insertion port 21. Or an IC card read / write section for storing data in the data storage area 4g in the memory 4.

The full text of the central processing unit 11 to the IC card 1 is composed of a function code, identification data, time data, and processing data as shown in FIG. 6, where the identification data is the limit described above. It consists of a flag indicating whether or not to confirm by data.

For example, as shown in FIG. 7, when the 0th bit (MSB or LSB) is " 1 " in the 8-bit configuration, it indicates that the time data (extreme value, warning value) is confirmed. "0" indicates that no time data is to be checked. If the first bit is "0", it means to check the recording capacity (extreme value, warning value). The first bit is "0". Indicates that the recording capacity is not checked, and when the second bit is "1", it indicates that the accumulated value (extreme value, warning value) is to be checked, and when the second bit is "0", It is shown that the accumulation value is not checked. The confirmation identification data is set in advance in the IC card handling unit 10 so as to be stored in an internal memory (not shown) in the central processing unit 11.

The IC card reading / recording unit 20 is connected to the card handling unit 10 main body by a cable 22.

That is, in the IC card reading / recording unit 20, as shown in FIG. 8, a conveying passage 31 for conveying the IC card 1 inserted from the card insertion opening 21 is provided, and this conveying passage 31 is provided. ) Is provided with a plurality of conveying rollers 32, which are arranged in a pair and are rotated so as to be tightened from the top and the bottom when conveying the IC card 1, and each conveying roller provided in the pair is provided. 32 are provided along the conveying path 31 at equal intervals so that the distance from the center of each of these conveying rollers 32 to the center of the conveying rollers 32 adjacent to each other is in the conveying direction of the IC card 1. Since the dimension of the width | variety with respect to the bar, the conveyance path 31 of the IC card 1 is defined by the conveyance guide 33 by this.

On the conveyance guide 33, a read / write section 34 is provided for exchanging data with the central processing unit 3 in the IC card 1, and the read / record section 34 is connected to the connector section. It is connected to 2) electrically.

The electric circuit of the IC card read / write section 20 is constructed as shown in FIG. That is, it comprises a central processing unit 51 for controlling the whole, a ROM 52 in which a control program is stored, a RAM 53 in which data is stored, and the read / write unit 34.

Hereinafter, the configuration as described above will be described with reference to the flowcharts shown in FIGS. 10A to 10C.

When the user inserts the IC card 1 into the card insertion opening 21, the IC card 1 is electrically connected to the read / write section 34 by the connector section 2, from which the user can, for example, trade When data and the like are inputted to the keyboard 12, the central processing unit 11 according to the year and date read out from the internal timer (not shown), the function identification code corresponding to the identification data and the transaction data, and processing data A full text is created and supplied to the central processing unit 3 through the read / recorder 34, the connecter 2, and the interface circuit 5 in the IC card read / recorder 20. The central processing unit 3 receives the full text and stores it in the RAM 6.

Subsequently, the central processing unit 3 determines whether or not the 0 th bit, which is the identification data in the telegram, is "1" (step 61). If the determination result is "1", the central processing unit 3 Is judged to check the time data (extreme value, elapsed value) (step 63).

Then, the central processing unit 3 stores the full-time date (time data) stored in the RAM 6 and the date (time data) stored in the storage area 4a in the limit data storage area of the data memory 4. (Step 65), and when the date of the preamble reaches the extreme date, the CPU 3 determines that the temporal limit is reached (step 67). The full text indicating the point of arrival is output to the CPU 11 (step 69).

Accordingly, the central processing unit 11 confirms that the inserted IC card 1 has reached the temporal limit, displays the summary with the CRT display device 13, and recovers the IC card 1 or inserts the card into the card slot. Discharged to (21).

As a result of the comparison in step 65, when the date of the full text does not reach the limit value, the CPU 3 judges that the temporal limit has not been reached (step 67), and stores it in the RAM 6. The date (time data) in the full text is compared with the date (time data) stored in the storage area 4b in the limit data storage area of the data memory 4 (step 71).

When the date of the preamble reaches the date as the warning value, the CPU 3 determines that the warning value of the temporal limit has been reached (step 73), and reaches the warning value of the temporal limit. The full text indicating the gist is output to the central processing unit 11 (step 75), and the process proceeds to step 77.

Accordingly, the central processing unit 11 confirms that the inserted IC card 1 has reached the warning value of the temporal limit, and displays the summary by the CRT display device 13.

As a result of the comparison in step 71, when the date of the full text does not reach the date as a warning value, the CPU 3 determines that the warning value of the temporal limit has not been reached (step 73). Will move to the stage.

Subsequently, when it is determined in step 73 that the warning value of the temporal limit has not been reached, and when it is determined in step 63 that the time data (extreme value, warning value) is not checked, the central processing unit 3 In step 77, it is determined whether the first bit of the confirmation identification data stored in the RAM 6 is " 1 ". If the determination result is " 1 ", the CPU 3 It is determined that the storage capacity (extreme value, warning value) is checked (step 79).

The central processing unit 3 then stores the full-text processing data stored in the RAM 6 in the data storage area 4g and the storage area 4c in the limit data storage area in the data memory 4. ) Is compared with the final address value (extreme value) stored in step (81). When the final address value is reached as a result of the comparison, the central processing unit 3 has a saturation capacity of the data memory 4. In operation 83, the full text indicating that the storage capacity is saturated is output to the CPU 11 (step 89).

Accordingly, the central processing unit 11 confirms that the storage capacity of the inserted IC card 1 is saturated, displays the summary with the CRT display device 13, and collects the IC card 1 or retrieves the card. It is discharged to the insertion port 21.

When the final address value has not been reached as a result of the comparison in step 81, the central processing unit 3 determines that the capacity of the data memory 4 is not saturated (step 83). The address when data is stored in the data storage area 4g is compared with a predetermined address value (alert value) stored in the storage area 4d in the limit data storage area in the data memory 4 (85) step).

When the predetermined address value is reached as a result of the comparison, the central processing unit 3 determines that the capacity of the data memory 4 reaches the warning value (step 87), and the storage capacity reaches the warning value. The full text indicating the summary is output to the central processing unit 11 (step 91).

As a result, the central processing unit 11 confirms that the storage capacity of the inserted IC card 1 has reached the warning value, and displays the fact by the CRT display device 13.

As a result of the comparison in step 85, when the predetermined address value has not been reached, the CPU 3 judges that the capacity of the data memory 4 has not reached the warning value (step 87). The process proceeds to step 93.

Subsequently, when it is determined in step 87 that the capacity of the data memory 4 has not reached the warning value, or when it is determined in step 79 that the storage capacity (extreme value, warning value) is not checked, the central storage device (3) determines whether or not the second bit of the identification identification data in the telegram stored in the RAM 6 is " 1 " (step 93). If the determination result is " 1 ", the central processing unit (3) judges that the accumulation value (extreme value, warning value) is confirmed (step 95).

Then, the central processing unit 3 performs the virtual accumulation value and data storage 4 in the case where the full-text processing data stored in the RAM 6 is added to the accumulation value stored in the data storage area 4g. The accumulated value (extreme value) stored in the storage area 4e in the limit data storage area is compared (step 97). If the virtual accumulated value reaches the extreme value as a result of the comparison, the CPU 3 It is determined that the accumulated value of the memory 4 has reached the limit value (step 99), and the full text indicating the summary that the accumulated value has reached the limit value is output to the central processing unit 11 (step 107).

As a result, the central processing unit 11 confirms that the accumulated value of the inserted IC card 1 has reached the limit value, displays the summary with the CRT display device 13, and recovers the IC card 1. Or discharged to the card insertion opening 21.

As a result of the comparison in step 97, when the accumulated value does not reach the limit value, the CPU 3 judges that the accumulated value does not reach the limit value (step 99) and uses the virtual accumulated value as a new accumulated value. The data is written to the data storage area 4g (step 101). The central processing unit 3 then compares the new accumulated value with the accumulated value (alert value) stored in the accumulated warning value storage area 4f in the data memory 4 (step 103).

As a result of the comparison, when the warning value is reached, the central processing unit 3 determines that the accumulated value has reached the warning value (step 105), and indicates the summary that the accumulated value has reached the warning value. The full text is output to the central processing unit 11 (step 109).

Accordingly, the central processing unit 11 confirms that the accumulated value of the inserted IC card 1 has reached a warning value, and displays the summary by the CRT display device 3.

When the accumulated value does not reach the warning value as a result of the comparison in step 103, the central processing unit 3 determines that the accumulated value has not reached the warning value (step 105) and centralizes the full text indicating the end of processing. Output to the device 11 (step 111).

Accordingly, the central processing apparatus 11 confirms the end of the processing of the inserted IC card 1 and discharges the IC card 1 to the card insertion portion 21.

If it is determined in step 95 that the accumulated value (extreme value, warning value) is not checked, the central processing unit 3 performs processing corresponding to the preamble stored in the RAM 6, that is, the function code and the processing data. The processing is then performed (step 113).

When the processing ends, the central processing unit 3 outputs the full text indicating the end of the processing to the central processing unit 11 (step 115), whereby the central processing unit 11 inserts the inserted IC card. The completion of the processing in (1) is confirmed, and the IC card 1 is discharged to the card insertion opening 21.

As described above, three types of limit recognition are executed reliably, and only the data indicating whether the card is valid or invalid is output, so that the specific data stored in the card can be easily made by the third party by the card user and the card handler. It can be prevented from being read.

Hereinafter, another embodiment of the present invention will be described with reference to FIGS. 11 to 16.

The IC card 1 is carried by the user, for example, at the time of purchase of the product, for reference of a password number known only by the user, or the accumulation of necessary data, and the like. As shown in FIG. 11, the reading / recording unit 117 is shown. ), A portion for executing basic functions such as an encryption setting / password control unit 119 and an encryption / decryption unit 12, and a supervisor 123 for managing these basic functions.

Here, the read / recording unit 117 reads, records, or erases data between the card read / write unit 20 and the password setting / password control unit 119 sets a password number set by the user. Memory and read prohibition processing, and after setting the password number, the password number is collated to grant permission for subsequent processing, and the encryption / decryption unit 121 is, for example, a central processing unit through a communication line. Encryption algorithm for preventing data leakage and forgery when transmitting data from 11 to 11 or decrypting the encrypted data, for example, an encryption algorithm having sufficient encryption strength such as DES (Data Encryption Standard). Function to perform data processing according to the above, and the supervisor 123 inputs a function code or data input from the IC card read / write unit 20. And a function to decrypt the cord is in addition to the function to be performed by selecting the required function of the basic function.

In order to exert these various functions, the IC card 1 according to the present embodiment includes, for example, a central processing unit 125 (CPU), a nonvolatile data memory 127 in which stored contents can be erased, The program memory 129 and the connector 131 for obtaining electrical contact with the IC card read / write section 20 are provided. However, among these, the portion in the dotted line (the central processing unit 125, the data memory 127 and the program memory 129) is integrated into an IC chip.

In addition, the program memory 129 is composed of a mask ROM to store a control program of the central processing unit 125 having subroutines for realizing the respective basic functions, and the data memory 127 stores various data. It is used for, for example, it consists of EEPROM.

The data memory 127 is a specific information storage area is divided into (127 ₁₎ and the data storage area (127 _2), wherein for a specific information storage area (127 ₁₎ has a plurality of individual authentication, as shown in claim 13 is also It consists of the coding region (127 _3), and the initialization completion flag area (127 ₄₎ for which the password number as identification information, the upper limit value and a region of the control data corresponding to the number of inconsistencies is stored respectively.

The upper limit value of the number of mismatches of the information is stored at the time of initialization of the IC card 1, and whether or not the initialization of the IC card 1 is completed is based on the state of the initialization completion flag. 125).

FIG. 11 conceptually shows each function in another embodiment of the present invention. The supervisor 123 in FIG. 11 is realized by the central processing unit 125 in FIG. Each of the circuit portions of the encryption setting / password control unit 119 and the encryption / decryption unit 121 is executed by the central processing unit 125 under the control of each control program stored in the program memory 129.

Next, the operation of the central processing unit 125 in the above configuration will be described with reference to the flowchart shown in FIG.

As shown in FIG. 14, the central processing unit 125 receives command data and analyzes it in step 133, and executes it. In this case, the command data includes only function codes as shown in FIG. As shown in Fig. 15B, there is one composed of a function code and data added thereto. In addition, the function code can be broadly executed at the time of initialization and at the completion of initialization.

When the command data is input to the IC card 1, the central processing unit 125 determines whether or not it is for initialization according to the function code included in the command data in step 135. the central processing unit 125 is to determine whether or not with reference to the initialization completion flag area (127 ₄₎ in step 137 the initialization is completed.

If the initialization is completed, the central processing unit 125 outputs the response data indicating a command error in step 139 and returns to step 133. If the initialization is not completed, the central processing unit 125 returns the command data in step 141. After execution, the response data indicating the completion of the execution is outputted, and the process returns to step 133.

On the other hand, if the function code is not for initialization in step 135, the central processing unit 125 refers to the initialization completion flag area (127 ₄ ) in step 143, in this case, if the initialization is not completed in step 139 It outputs the response data, which means and returns to step 133.

Here, if the command data for setting the upper limit value of the check mismatch is classified into the command data at the time of initialization, the upper limit value can be freely set at the time of initialization, and once the initialization is completed, the setting of the command data becomes impossible and the check mismatch is made. The upper limit of the number of times cannot be changed from the outside.

Next, the operation at the time of cryptographic matching will be described with reference to the flowchart shown in FIG.

As shown in FIG. 17, the encryption control command data is composed of a matching function code 145, index data 147, and matching data 149. As shown in FIG.

When the instruction data is input in the 151 step there is to check the central processing unit 125, the index data included in the instruction data and the German indexed in 153 steps from the encryption region (127 _3), wherein the index data is not found. If not, output the response data indicating that the operation is not possible in step 157, and then returns to step 151. If the index data is found, in step 159 the password number and input in the password area (127 ₃ ) corresponding to the index The comparison data is compared.

If it is determined in step 161 that the verification result is positive, the CPU 125 outputs the response data of the card permission in step 163.

On the other hand, the verification result is when the so determined in the negative in 161 steps in 165 steps the CPU 125 checks the x-th negative result of reach the upper limit value of the mismatch count in the coding region (127 ₃₎ corresponding to the index If not, after outputting the response data indicating the inconsistency in step 167, the process returns to step 151. If the upper limit of the number of inconsistencies is reached, the response data indicating the prohibition of card use is output in step 169. Command data will not be accepted.

In this way, the upper limit of the number of mismatched ciphers of the IC card can be freely set at the time of initializing the IC card so that the number of mismatches can be matched to other applications using one type of IC card. Since the command data cannot be changed, the security as an IC card system can also be maintained.

In the above embodiment, the case where the data memory is an EEPROM has been described, but the present invention is not limited thereto, and the same can be applied to the case of an EPROM, a RAM, or the like.

In the above embodiment, the IC card is exemplified as a portable electronic device. However, the present invention is not limited to a card shape, but a block or pencil shape can be used, and a hardware structure of the portable electronic device can be used. It is also possible to deform in various ways within the scope without departing from the gist.

[Effects of the Invention]

As described above, according to the present invention, a portable electronic device capable of using a single portable electronic device to correspond to each application having a different number of matching discrepancies and also maintaining confidentiality It can be realized.

Claims (9)

A portable electronic device, which is connected to a host system having a display unit 13 with a removable material, includes an extreme value storage area for storing data representing an extreme value of an effective use limit, and a warning close to the extreme value. A storage means 4 constituted by a warning value storage area for storing data representing a value and whether or not the extreme value data transmitted from the host system has exceeded an extreme value stored in the extreme value storage area of the storage means 4; First comparison means (3) for outputting the comparison result and comparing whether or not the temporal limit value data has exceeded the warning value stored in the warning value storage area of the storage means (4) and outputting the comparison result; An output for outputting the comparison results from the second comparing means 3 and the first and second comparing means 3 to the host system so as to be displayed on the display section 3; A portable electronic device capable of being configured by comprising a stage (11). The portable electronic device according to claim 1, wherein said storage means (4) is constituted by a PROM. The portable electronic device according to claim 1, wherein said storage means (4) is constituted by an EEPROM. The portable electronic device according to claim 1, wherein the limit storage area of said storage means (4) is a time data limit value storage area (4a) for storing time data representing an extreme value of a temporal limit. The portable device according to claim 1, wherein the warning value storage area of said storage means (4) is a time data warning value storage area (4b) for storing time data representing a warning value which is a value close to the limit value. Electronics. The portable electronic device according to claim 1, wherein the limit storage area of said storage means (4) is an accumulated limit value storage area (4e) for storing data representing an extreme value of a record accumulation value. 2. The portable device according to claim 1, wherein the warning value storage area of said storage means (4) is an accumulated extreme warning value storage area (4f) for storing data representing a warning value which is a value close to an extreme value of said recording accumulation value. Capable electronics. The limit value storage area of the storage means 4 is a storage capacity limit value storage area 4c for storing data representing a limit value of the storage capacity of the storage means 4 itself. Portable electronics. The storage capacity warning value storage area (4d) according to claim 1, wherein the warning value storage area of said storage means (4) stores data representing a value close to a limit value of the storage capacity of the storage means (4) itself. Portable electronic device, characterized in that.

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