JPH0746376B2 - IC card - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Object of the Invention] (Field of Industrial Application) The present invention relates to an IC card for storing data in a built-in data memory.

(Prior Art) Recently, as a new portable data storage medium, an IC having a nonvolatile data memory and a control element such as a CPU
An IC card with a built-in chip is disclosed. Of this kind
The IC card stores, reads, and erases data in a data memory incorporated by an internal control element or an external device.

Conventionally, in such an IC card, as a method for storing data in a data memory, a method has been considered in which one unit of data to be stored is divided and stored with a certain fixed length. In this case, a record number as the storage information is added to each unit of data and stored. When the data stored in this way is accessed, the record number added to each data is searched in order to find the target record number and read the corresponding data.

However, in such a data storage system, a record number is required as storage information for each data, so that there is a problem that the memory area cannot be effectively used and the memory efficiency is reduced. Further, when accessing the stored data, it is necessary to search the record numbers in order, which causes a problem that the access time becomes long.

(Problems to be Solved by the Invention) As described above, in the conventional IC card, there is a problem that the memory area cannot be effectively used and the memory efficiency is lowered. Moreover, when accessing the stored data, There is a problem that access time becomes long.

Therefore, the present invention solves the above problems, and provides an IC card in which a memory area can be effectively used, memory efficiency is improved, and access time of stored data can be shortened. With the goal.

[Structure of the Invention] (Means for Solving Problems) The present invention is an IC card for writing data received from an external device in a predetermined word unit to a built-in memory, wherein the word in the memory is used. Length storing means for storing the length information of the above, a dividing means for dividing the data received from the external device into fixed lengths based on the word length information stored in the word length storing means, and this dividing means. First writing means for writing the head data divided by the above into a word area at one end of the memory area, and the divided data continuing after the head data is the other end of the memory area of the memory. Second writing means for sequentially writing from the word area and whether or not there is continuous data in the data when the data is written by the first writing means and the second writing means. judge The determining means, a third writing means for writing the data indicating the end of the data to the word area when the determining means determines that there is no continuous data, and the determining means If it is determined that there is continuous data in the data, the position information of the word area continuing in the data is written in the word area.
Writing means.

(Operation) The record number is set in the storage order of the divided head data, and the storage position of the head data can be recognized by this record number and the fixed length. Then, the storage position of the divided data continuing after the head data can be recognized by the storage position information added to the head data. Therefore, it is not necessary to add a record number to each data as in the conventional case, the memory area can be effectively used, and the memory efficiency is improved. Further, since the data can be directly accessed by inputting the record number when reading the stored data, the access time becomes significantly faster than the conventional method of sequentially searching the record numbers.

(Example) Hereinafter, one example of the present invention will be described with reference to the drawings.

FIG. 18 shows an example of the configuration of a card handling device to which the IC card according to the present invention is applied, which is used as a terminal device such as a home banking system or a shopping system. That is, this device enables the IC card 1 to be connected to a control unit 3 including a CPU via a card reader / writer 2, and the control unit 3 includes a keyboard 4, a CRT display device 5, a printer 6, and a floppy disk device. 7 are connected.

The IC card 1 is held by the user, and refers to a personal identification number known only to the user when the product is purchased, for example, and stores necessary data. As shown in FIG. 16, its functional block is shown. In addition, read / write section 11, password setting
The password collation unit 12 and the encryption / decryption unit 13 perform basic functions, and the supervisor 14 manages these basic functions. Read / write part 11
Reads data from / to the card reader / writer 2,
It is a function of writing or erasing. PIN code setting
The personal identification collation unit 12 has a function of performing storage and reading prohibition processing of the personal identification number set by the user, performing collation of the personal identification number after setting the personal identification number, and permitting subsequent processing. The encryption / decryption unit 13 encrypts or prevents encrypted data from being leaked or forged when transmitting data from the control unit 3 to another terminal device via a communication line, for example. Is for compounding,
For example, it is a function of performing data processing in accordance with an encryption algorithm having sufficient encryption strength such as DES (Data Encryption Standard). The supervisor 14 is a function that decodes the function code or the function code added with data input from the card reader / writer 2, and selects and executes a necessary function from the basic functions.

In order to exert these various functions, the IC card 1 has, for example, as shown in FIG. 15, a control element (for example, CPU) 15 as a control unit, and nonvolatile data in which the stored contents as a data memory unit can be erased. It comprises a memory 16, a program memory 17 as a program memory section, and a contact section 18 for making electrical contact with the card reader / writer 2. Of these, a portion within a broken line (control element 15, data memory) 16, the program memory 17) is composed of one IC chip. The program memory 17
For example, it is composed of a mask ROM and stores a control program of the control element 15 having a subroutine for realizing each of the basic functions. The data memory 16 is used to store various data and is composed of, for example, an EEPROM.

The data memory 16 is divided into a plurality of areas, for example, as shown in FIG. 2, and area numbers [00 to FF] are given to the respective areas. Among these, in the area [00], the respective start addresses of all areas, the number of bytes forming the area, and the fixed length dividing the area are stored in correspondence with the area number. For example, the start address of area [02] is address A ₀₂ , the number of bytes making up the area is S ₀₂ bytes, and the fixed length dividing the area is L ₀₂ bytes.

The card reader / writer 2 exchanges function codes and data between the IC card 1 and the control unit 3. Specifically, as shown in FIG. 17, a transport mechanism 21 for transporting the IC card 1 inserted in a card insertion slot (not shown) to a predetermined position, and a contact portion 18 of the IC card 1 set at the predetermined position. A contact portion 22 that is electrically contacted with a control circuit 23 including a CPU that controls the entire control
The control unit 3 includes an input / output interface circuit 24 for transmitting and receiving command data and response data, a data memory 25 for storing data, and the like.

Next, the data storage system of the present invention having such a configuration will be described in detail. First, the area system of the data memory 16 of the IC card 1 is shown in FIG. The data storage area [00 to FF] is divided into areas by the directory [00]. Each divided area is divided into words having a fixed length (L bytes) depending on the directory. The word number given to each word is not stored anywhere but is counted from the top (or bottom) word each time it is searched.

When writing (storing) data in the data memory 16,
Write command data having a format as shown in FIG. 4 is input. This write command data is composed of a write function code, an area number, byte number information (LNG) indicating the length of data, and storage data.

The stored data is divided into a predetermined fixed length. And the state that it was divided into a word system is the fifth
Shown in the figure. As shown in FIG. 5, the word system is composed of a control block (Control Block), a chain number (Chain Number) as storage location information of the divided data continuing thereafter, and the divided data.

The control block indicates the guarantee and accuracy of the data below it. As shown in FIG. 6, the valid flag (Delete flag) and the delete flag (Delete Fla
g) and a first flag. The valid flag is for determining whether or not data has been written correctly and is in a readable state when writing data to a word having this flag. The delete flag indicates whether the word exists and data can be read. The first flag is a word (directory word; Directy Ward) that contains the LNG of the data before the data in that word is divided, or
Indicates whether it is another word (follow word; Follow Ward).

The chain number stores the word number of the word in which the data to be connected next to that word is stored. In particular, in the case of data that can be expressed by one word or the last word, it is determined by inserting a specific character.

FIG. 7 shows a state in which the stored data is divided into fixed lengths of L bytes, and FIG. 8 shows a state in which a control block (CB) and a chain number (CN) are added to each of the divided data to form words. The area shown in FIG. 9 is stored in the area shown in FIG. As shown in FIG. 9, the head (directory word) of the divided data is stored from above the area, and the divided data (follow word) following it is stored from below the area.

Below, writing (storing) data to the data memory 16
The processing will be described with reference to the flowchart shown in FIG. First, in the steady state, the card reader / writer 2
When the command data is input from the card reader / writer 2 at this time, the control element 15 first confirms whether the function code included in the command data is the write function code. To do. If it is the write function code, the control element 15 searches the area "00" of the data memory 16 for the area number added to the instruction data. If not found, the control element 15 outputs the response data indicating that the area has not been confirmed, and returns to the command data waiting state. If found, the control element 15 holds the start address of the corresponding area, the number of bytes forming the area, and the fixed length dividing the area in the built-in RAM,
Recognize the position of the target area. Next, the control element 15 divides the storage data added to the instruction data from the beginning with a length (byte) obtained by subtracting the sum of the control block (CB) and the chain number (CN) from the fixed length L of the area. Then, the divided data is held in the built-in RAM.

Next, the control element 15 determines whether or not the pointer data points to a word for newly writing the directory word. This ensures that the control element is
Reference numeral 15 outputs response data indicating a pointer data error, and returns to the instruction data waiting state. When the validity is confirmed, the control element 15 calculates the number of bytes to be actually written by the number-of-bytes information added to the instruction data, and judges whether or not the data storage area is secured accordingly. Do. If not secured, the control element 15 outputs response data indicating an error in the number of input data bytes and returns to the instruction data waiting state. If secured, control element
Reference numeral 15 adds a control block and a chain number (actual writing of the chain number will be performed later) to the head data (directory word) of the divided data stored in the RAM by the pointer data, and writes it in the area. Then, the control element 15 sets the first flag of the control block to "0".

Next, the control element 15 determines whether or not there is data (following word) following the directory word. When there is no follow word, the control element 15 operates as follows in FIG. If there is a follow word, the control element 15 searches the last word of the area for an unwritten word and writes the follow word. Then, the control element 15 writes the word number of the word just written into the chain number of the previously written word. Next, the control element 15 determines whether or not there is a follow word following the word just written. When there is a follow word, the control element 15 operates as shown in FIG. When there is no follow word, the control element 15 writes information such as “END” in the chain number. Then, the control element 15 sets the valid flags of the control blocks of all the written words to "0", and then stores the new leading word of the directory word as pointer data. Then, the control element 15 outputs the response data indicating the completion of writing and returns to the instruction data waiting state.

Next, the process of reading data from the data memory 16 will be described with reference to the flowchart shown in FIG. When reading data from the data memory 16, read instruction data having a format as shown in FIG. 11 is input. This read command data is composed of a read function code, an area number and a record number. First,
The steady state is in a state of waiting for command data from the card reader / writer 2, and when command data is input from the card reader / writer 2 at this time, the control element 15 first detects the function code included in the command data. Check if it is a read function code. If it is a read function code, the control element 15 searches the area "00" of the data memory 16 for the area number added to the instruction data. If not found, the control element 15 outputs the response data indicating that the area has not been confirmed, and returns to the command data waiting state. If found
The control element 15 extracts the record number added to the command data. The area of the control element 15 is fixed length L
Since it is divided by, the predetermined number (fixed length L × record number) is calculated between the fixed length L and the extracted record number to calculate the word number from the beginning of the area, and the word The data (directory word) of the word indicated by the number is read. Next, the control element 15 extracts the chain number of the read data (head data) and determines whether or not the chain number is information indicating "END". If it is not "END", the control element 15 reads the data of the word corresponding to the word number indicated by the chain number (data continuing from the above-mentioned head data), and the following operation in FIG. 10 is performed. "EN
If it is "D", the control element 15 indicates that the control block (CB) and the chain number (C
The data excluding N) is connected and output, and the operation returns to the instruction data wait state. Note that the last word of the data has the unwritten portion removed by the LNG of the directory word.

As a specific example, assume that read command data as shown in FIG. 12 is input. This command data is for reading the data of the record number [02] of the area [02], which means that the data of the shaded area in FIG. 13 is read. FIG. 14 shows how the read data is output.

In this way, each divided area of the data memory is divided into words having a fixed length, the data to be stored is also divided into the fixed length, and all the divided data are stored in the divided data that continues thereafter. A word number (chain number) indicating the position is added. Then, store the divided top data in order from the top word side of the area,
Subsequent divided data is stored sequentially from the last word side of the area. According to such a data storage system, the record number is set in the storage order of the divided head data, and the storage position of the head data can be recognized from this record number and the fixed length. The storage position of the divided data that continues after the first data can be recognized by the word number added to each data.
Therefore, it is not necessary to add a record number to each data as in the conventional case, the memory area can be effectively used, and the memory efficiency is improved. Further, since the data can be directly accessed by inputting the record number when reading the stored data, the access time becomes significantly faster than the conventional method of sequentially searching the record numbers.

Since the data continuing to the divided head data is stored in order from the last word side, it is not always necessary to add the storage position information of the data continuing after that to the continuing data.

[Advantages of the Invention] As described in detail above, according to the present invention, the memory area can be effectively used, the memory efficiency is improved, and the access time can be shortened when the stored data is accessed.
Cards can be provided.

[Brief description of drawings]

FIG. 1 is a diagram for explaining one embodiment of the present invention. FIG. 1 is a flow chart showing a data writing process, FIG. 2 is a diagram showing a configuration of a data memory, and FIG. 3 is an area system of the data memory. FIG. 4, FIG. 4 is a diagram showing a format of write command data, FIG. 5 is a diagram showing how data is divided into a word system, and FIG. 6 is a diagram showing a configuration of a control block. The figure shows how the data is divided into fixed lengths, Fig. 8 shows how each divided data is added with a control block and chain number, and is worded. Fig. 9 shows how the data is stored in the area. FIG. 10, FIG. 10 is a flowchart showing a data read process, FIG. 11 is a view showing a format of read command data, FIG. 12 is a diagram showing a specific example of the read command data, and FIG.
FIG. 14 is a diagram showing a concrete example in the data memory, FIG. 14 is a diagram showing a concrete example of output of read data, FIG. 15 is a block diagram showing the configuration of an IC chip incorporated in the IC card, and FIG. 16 is I c
FIG. 17 is a block diagram showing a functional block of a card, FIG. 17 is a block diagram showing a configuration of a card reader / writer, and FIG. 18 is a block diagram showing a configuration of a card handling device. 1 …… IC card, 2 …… Card reader / writer, 15 ……
Control element, 16 ... Data memory (storage medium), 17 ... Program memory.

Claims (1)

[Claims] 1. An IC card for writing data received from an external device into a memory in which a predetermined word unit is written, and word length storage means for storing word length information in the memory, Dividing means for dividing the data received from the external device into fixed lengths based on the word length information stored in the word length storing means, and the leading data divided by the dividing means are stored in the storage area of the memory. First writing means for writing in the word area at one end, and second writing means for sequentially writing the divided data continuing after the head data from the word area at the other end of the memory area of the memory Determining means for determining whether or not there is continuous data in the data when the data is written by the first writing means and the second writing means; If it is determined that the data to be written does not exist, a third writing unit that writes data indicating the end of the data to the word area, and if the determination unit determines that there is continuous data to the data Is a fourth writing means for writing the position information of the word area continuing to the data in the word area.