JPS63224092A - Data storage system - Google Patents

Abstract

PURPOSE:To easily recognize a data to be the head of a chain by adding a bit of recognition information together with a bit of chain information to the divided data, and storing them, and besides, making a bit of discrimination information added to the data to be the head a bit of specified information. CONSTITUTION:A means dividing the data into plural pieces, and the means storing the divided data in a storage medium, after adding the discrimination information and the chain information to the divided data, are provided, and the discrimination information, added to the data to be the one end of the chain is the specified information. The data is divided into plural pieces according to a cenception called as a word, and the respective divided data is stored after adding the chain information and the recognition information to them, and besides, the discrimination information, added to the data to be the head of the chain is made to be the specified information. Thus, the data to be the head of the chain can be easily recognized.

Description

DETAILED DESCRIPTION OF THE INVENTION [Object of the Invention] (Industrial Application Field) The present invention relates to a data storage method for storing data in a data memory of a tC card, for example.

(Prior Art) Recently, an IC card containing a built-in IC chip having a nonvolatile data memory and a control element such as an 08 port has been developed as a new portable data storage medium. This type of IC card accesses a built-in data memory using a built-in control element, and performs input/output of necessary data in response to a request from an external device. In addition, the data memory is divided into multiple areas, allowing you to selectively
- Access to the rear is now possible.

Conventionally, in such an IC card, the data storage method in the data memory has been to arrange and store data in the order of access. With this method, when there is a plurality of data in an area and when any data is to be replaced, the length of the data before rewriting must match the length of the rewritten data. For example, if the former data length is larger than the latter data length, the data to be rewritten and the next data may have several bytes (
If a blank space (or several words) occurs, and if it is small, the next data and subsequent data must be shifted to ensure space for storing the rewritten data.

As a countermeasure to these shortcomings, one unit of data to be stored is divided into multiple parts using the concept of words, and each of the divided data is stored with chain information added to them, thereby creating a word storage method. A method that provides a degree of freedom can be considered. However, in this method, each end of the chain is treated as data! ! ! must be able to understand.

(Problems to be Solved by the Invention) The present invention provides a method for dividing data into a plurality of parts as described above, and when each of the divided data is stored with chain information added thereto, each chain becomes the first chain as data. This was done in view of the need to be able to recognize the leading edge of data, and the purpose is to provide a data storage method that allows for easy recognition of which data is the leading edge of data connected by chain information. shall be.

[Structure of the Invention] (Means for Solving the Problems) The present invention is a data storage method for storing data in a storage medium, comprising means for dividing the data into a plurality of pieces;
and means for adding identification information and chain information to each of the divided data and storing it in the storage medium,
It is characterized in that the identification information added to the data that is one end of the chain is specific information.

(Function) By storing +I information with chain information added to each divided data, and by making the above identification information added to the data at the top of the chain as specific information, this specific information is used to identify the top of the chain. Data that becomes can be easily aS.

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

FIG. 9 shows an example of the configuration of a card handling device used as a terminal device in, for example, a financial system or a shopping system, to which the IC card according to the present invention is applied. That is, this device reads an IC card 1 through a card reader/writer 2, which is composed of a CPLJ, etc.
In addition to being connectable to the llllO section 3, the control section 3 is also equipped with a keyboard 4, a CRT display device 5, and a printer 6.
and a floppy disk device 7 are connected.

FIG. 8 shows a configuration example of the IC card 1, which includes a control element (for example, CPLJ) 11 as a control section, a nonvolatile data memory 12 whose storage contents can be erased, a program memory 13, and a card reader/writer 2. The contact part 14 is configured to establish electrical contact with the IC card body, and the parts within the broken line (control element 11, data memory 12, program memory 13) are comprised of one IC chip and are connected to the IC card body. It is buried inside. The program memory 13 is composed of, for example, a mask ROM, and stores a control program for the control element 11 and the like. The data memory 12 is used to store various data and is composed of, for example, an EEPROM.

The data memory 12 is divided into a plurality of areas, as shown in FIG. 5, for example, and each area is given an area number [00, 01, . . . ]. Among these, area [00] includes area [01, 02,...
The starting address of each bow, the number of words dividing the area, and the number of bytes of each word are stored in correspondence with the area number. For example, the start address of area [01] is address aaa, the number of words dividing the area is Wa, and the number of bytes of a word is SaS bytes. And each area [01゜02,...
.] is divided into words having a fixed length (S bytes), and each word is assigned a word number. In addition, the word number is a hexadecimal character () with the word located at the beginning of the area being "1" and increasing by 1 from then on.
-1ex) data.

FIG. 6 shows a state in which data is stored in a certain area, and chain information and identification information are added to each divided data. As the chain information, the word number of the word in which the subsequent data is stored (that is, the storage position information of the subsequent divided data) is used. Identification information specifies whether the data is the tip of the chain or not.
For example, as shown in FIG. 7, it is composed of 1 byte (8 bits), of which the most significant bit (MSB) is used and the others are dummy. In other words, the MSB is “0”
If it is 111 I+, it indicates that it is the first data, and if it is 111 I+, it indicates that it is other than that.

Next, the data storage method of the present invention in such a configuration will be explained in detail. When writing data to the data memory 12, write command data having a format as shown in FIG. 3 is input from the card reader/writer 2 to the IC card 1.

In the IC card 1, the tllIIl element 11 recognizes the write function code included in the write command data and executes the write process based on the flowchart shown in FIG. That is, first, the total number of bytes of write data is determined by the data length included in the input harmful command data.
Then, it is determined whether all the information can be stored in the access target area. If it cannot be stored, response data indicating a byte count error is output and the process is terminated. If it can be stored, the write data included in the input write command data is divided into words by the number of bytes, and sequentially written word by word into the access target area of the data memory 12. At this time, the word number of the written word is
It is temporarily held in RAM within 1. Then, when it is recognized that all of the divided data has been correctly written, the word numbers held in the RAM are added as chain information in order from the word written last. In this case, the chain information of the last written word is set to "0" to indicate that it is the last data in the chain, and the next chain information and subsequent words are R.
Allocate to AM in order from the word number held last.

Then, the MSB of the identification information of the word to which the chain information is finally allocated is turned on to indicate that it is the data at the top of the chain, and response data indicating normal termination is output, and the process ends.

Here, to explain concretely using FIG. 6, for example, write data is written as Wl 1. Wl 2. Divide into Wl 3 and word number J in this order! Write sequentially to each word of r1.2 and 3J. At this time, the word number r1.2.
34 are stored in this order.

Next, add "0" to the chain information part of data W13,
"3" is in the chain information part of data W12, and data W1
“2” is added to the chain information location of “1”. Finally, the identification information M of the word W11 to which the chain information is added is
Turn on SB.

Next, when reading data from the data memory 12, read command data having a format as shown in FIG. 4 is input from the card reader/writer 2 to the IC card 1. In the IC card 1, the control element 11 recognizes the read function code included in the read command data and executes the read process based on the flowchart shown in FIG. That is, first, the identification information section in the access weighted area is referred to, and one whose MSB is "0" is found. If it is not found, response data indicating that data has not been written is output and the process ends. If found, then counting from the beginning, it is determined whether there is a word whose value is "0" or higher than the read target data number included in the input read command data.

If there is no data number to be read, response data indicating that there is no data number to be read is output and the process ends. If there is, the word whose MSB is "O" in the identification information that matches the data number to be read is referred to, and the data in that word is read and temporarily held in the RAM. Next, the word having the following data is recognized based on the corresponding chain information, and the data in that word is read out and added to the end of the data previously held in the RAM. This operation ends when the data of the word whose chain information is rOJ is held in RAM, and R
The data held in AM is output and the process ends.

In this way, data is divided into multiple parts using the concept of words, each of the divided data is stored with chain information and recognition information added to it, and the above-mentioned identification information added to the data at the tip of the chain is Specific information (e.g. “0”)
By doing so, the data at the top of the chain can be easily recognized using this specific information.

In the above embodiment, the case where data is stored in the data memory built into the IC card has been described, but the present invention is not limited to this, and data may be stored in other storage media. The same applies to cases where

[Effects of the Invention] As detailed above, according to the present invention, when data is divided into a plurality of pieces and each of the divided data is stored with chain information added thereto, the data connected by the chain information can be It is easy to know which data is the leading edge! ! It can provide a data storage method that can be easily understood.

[Brief explanation of the drawing]

The figures are for explaining one embodiment of the present invention, and FIG. 1 is a flowchart explaining the data rubbing process,
3 is a diagram showing an example of the format of write command data, FIG. 4 is a diagram showing an example of the format of read command data, and FIG. 5 is a diagram showing the configuration of the data memory. , FIG. 6 is a diagram showing the state in which data is stored in the area, FIG. 7 is a diagram showing the configuration of identification information, FIG. 8 is a block diagram showing the configuration of the IC card, and FIG. 9 is the configuration of the card handling device. FIG. 1...IC card, 2...card reader/writer, 11...control element (control unit), 1
2...Data memory (storage medium), 13...
...Program memory. Applicant's representative Patent attorney Takehiko Suzue No. 4 Figure 7 Figure 8 Figure 9

Claims (3)

[Claims] (1) A data storage method for storing data on a storage medium, which includes means for dividing the data into a plurality of pieces, and adding identification information and chain information to each of the divided data and storing the data on the storage medium. 1. A data storage method, characterized in that the identification information added to data that is one end of a chain is specific information. (2) The data storage system according to claim 1, wherein the data serving as one end of the chain is the first data of each of the plurality of pieces of data. (3) The data storage system according to claim 1, wherein the storage medium is a data memory provided in an IC card.