JPH04111086A - Ic card - Google Patents

Abstract

PURPOSE:To efficiently use a logic address space in a memory by providing a record control table to store coded address information for designating a record area, and an address converting means to prepare a logic address based on the address information. CONSTITUTION:A record control table 3 is provided to store the coded address information, and an address converting means 4 is provided to prepare the logic address. When performing access to a data stored in the record area of a file, a data access means 2 refers to the record control table 3, prepares the logic address space of a record based on the coded address information stored in the table 3 and accesses the data in the address space to be next designated by the logic address. Therefore, when reloading the data, it is enough to change the address information of the record control table 3, and it is not necessary to allocate the logic address space to each file in advance. Thus, the address space of a memory 1 is efficiently used.

Description

DETAILED DESCRIPTION OF THE INVENTION <Industrial Application Field> The present invention relates to an IC card, and particularly to a memory configuration included in an IC card.

<Prior art> Conventionally, in this type of IC card, multiple files are created in its memory, and a predetermined logical address space is assigned to the records that make up each file at the time of file creation, regardless of whether or not the record is used. It was assigned in advance.

<Problems to be Solved by the Invention> However, in such conventional IC cards, even if there is an unused portion in the logical address space of the memory allocated to the already created file, the unallocated logical address If there is not enough space to create a new file, the unused portion cannot be used to create a new file, and no new files can be created in that IC memory from now on. Can not. As a result, there is a problem that the logical address space cannot be used efficiently and is uneconomical.

SUMMARY OF THE INVENTION Therefore, an object of the present invention is to provide an IC card that can efficiently use the logical address space within the memory.

<Means for Solving the Problems> The gist of the present invention is that, as shown in FIG. 1, a memory 1 having a predetermined logical address space, a data access means 2,
In an IC card with address conversion means 4 for creating an address;
It is to have.

<Operations and Effects> In the IC card according to the present invention, when accessing data stored in the record area of a file,
The data access means is to H the record management table.
A logical address space of records is created based on the encoded address information stored therein. Next, the data access means accesses data within the address space specified by the logical address. therefore,
When rewriting data, it is only necessary to change the coded address information in the record management table, and there is no need to allocate a logical address space to each file in advance.

In this way, the file can variably occupy the address space used, so the memory address space can be used efficiently.

<Example> Embodiments of the present invention will be described below with reference to the drawings.

FIG. 2 is a phase diagram showing the memory configuration of the IC card.

FIG. 3 is a block diagram showing the file structure of each file of the IC card.

As shown in FIG. 2, the memory configuration of an IC card consists of a directory 11 managed by a bucogram executed by a microprocessor mounted on the IC card, and a plurality of files 12 managed in the directory 11. .

Further, as shown in FIG. 3, each file 12 stores externally supplied data 13a to 13c in a different logical address space X1. X2. X3. , , , record area 14 recorded for each type of data, and types 15a, 15b, 15 of data 13a to 13c stored in the record area in correspondence with each index.
c, . . . and a record management table area 16 that stores coded address information (or displacement amount if a relative addressing method is adopted) specifying the above-mentioned logical address space. .

These record area 14 and record management table area 16 are created separately for each file and are managed by the directory 11. That is, the fourth
As shown in the figure, the data format 21 of the directory 11 includes a section 22 for storing the file name 12, a section 23 for storing the start address 22 of the record area 13 of the file, and a record management table 16 for the file.
A section 24 that stores the start address of the area and the number of records (RLN) recorded in the record area 14
and a section 26 that stores the size of the address space occupied by the record area I4.

Therefore, the CPU of the IC card is
By searching the data format 21 of the file, you can find out from where in the logical address space of the IC card the record area 14 of the desired file is recorded, and from where in the logical address space of the IC card the record management table 16 of the file is recorded. It is possible to determine whether In addition, since the size of the logical address space occupied by the record area 14 is shown, the CPU of the IC card can also know the size of the unused address space.

Furthermore, the data format 31 of the record management table 16 shown in FIG. 5 creates a section 32 assigned to the index, a section 33 for storing the type of data, and a logical address of the record assigned to the data. It includes a section 34 for storing coded address information used for, for example, a relative address 32.

By searching the record management table 16, the CPU of the IC card can determine whether the type of data specified by the application software is stored in the file. Furthermore, IC card CP
By adding the start address of the record area 14 of the file and the relative address, U can create the logical address of the record in which the data specified by the application software is stored.

Incidentally, data reading or writing operations are performed between a data terminal and an IC card, and during such communication, the information is transmitted in units of variable length frames. Each frame is composed of one or more fixed-length bit strings called characters arranged in series.

First, the frame used for writing is shown in Figure 6 (a
) As shown in (b), what is used when writing is sent from the application (Figure 6 (a)! This is shown)
and what is sent from the IC card after writing is completed (
(shown in FIG. 6(b)).

Frame (a) used during writing includes a write/read instruction code, file name data, data (AIN) indicating the type of data to be written, data indicating the data size of the data to be written, and The data that should be sent is sent.

On the other hand, in frame (b) after writing, the write/read instruction code, the status data representing status STS 1 representing whether or not the writing operation has been completed, and the data supplied from the data terminal are correctly written. Status data representing status 5TS2 indicating whether or not the data has been received is transmitted.

As shown in FIGS. 7(a) and 7(b), the frames used for reading include those sent from the application (shown in FIG. 7(a)) and the frames used for reading after reading is completed. and the one transmitted from the card (shown in FIG. 7(b)).

In frame (a) used during reading, a write/read instruction code, file name data, and data indicating the type of read data are transmitted.

On the other hand, in frame (b) after reading, a write/read instruction code and status data representing status 5TS3 representing whether or not the reading operation has been completed,
Status data representing status 5TS4 indicating whether the data supplied to the data terminal has been read normally or not and data to be read are transmitted.

Software executed by an IC card according to one embodiment will be described below.

First, the operation order of the write subroutine will be explained using the flowchart shown in FIG.

First, assume that a data terminal specifies a file on an IC card and sends new data.

By executing the record management table search subroutine, the IC card's CPU searches the record management table and determines whether the type of data specified by the application software has already been recorded in the file that the application software is trying to access. (Step Sl).

That is, as shown in the flowchart of FIG. 9, first, the CPU of the IC card clears the flag SA (step 551). Then, the CPU of the IC card prepares to read the data specified by the first index of the record management table by setting the counter CNT1 to "1" (step 552). And I.C.
The card's CPU handles the data type (buffer RC) specified by the first index of the record management table.
(CNTI)) and the type of data (buffer AIN) recorded in the write command are determined (step 553). That is, it is determined whether the type of data specified by the application software has already been recorded in the file of the IC cart that the application software is trying to access. If the judgment result is YES, the type of data specified by the application software has already been recorded in the file of the IC cart that you are trying to access, so the flag SA is
is set to "1" (step 554).

Then, the CPU of the IC card ends the operation of the record management table search subroutine and returns to the write subroutine.

On the other hand, if the judgment result in step S53 is No, the type of data specified by the application software has not been recorded yet, and is recorded in the counter CNT1 and the file of the IC cart that the application software is trying to access. It is determined whether or not the number of records RLN is equal (step 555). That is, it is determined whether all records in the record management table of the IC cart that the application software is attempting to access have been searched.

If the judgment result is No, all the records in the record management table have not been searched, so "1" is added to the counter CNT1, and (CNT1
Step 557) prepares to read the data specified by the index '+]), and returns to step S53. In this way, the -rc card (7) CPU executes step S53. A loop consisting of steps S55 and S57 is repeatedly executed to search for all records in the record management table.

Eventually, when the determination result in step S55 becomes YES,
I that the application software is trying to access
Since the type of data specified by the application software is not recorded in the file of the C card, the flag SA is set to "0" (step 556), and the CPU of the IC card ends the operation of the record management table search subroutine. and return to the write subroutine.

Next, the operation of the CPU of the IC cart returns to the write subroutine and determines whether VlJ is set in the flag SA (step S2).

If the result of the determination is YES, the type of data specified by the application software has already been recorded in the file of the IC card to be accessed, so that the data will be corrected. That is, the CPU of the IC card determines whether the data exceeds the size of the record area recorded in the data format of the directory (step S3).

If the determination result is No, the size of the record area has not been exceeded, so the CPU of the IC card creates a logical address for recording the data (step S4). In detail, the relative address is determined by adding the deviation value indicated by the counter CNT1 recorded in the record management table to the start address of the record area recorded in the directory of each file, and the logical address of the recording destination is determined. Create an address.

Next, the CPU of the IC card modifies the data at the record position indicated by the logical address to the data supplied from the application software (step S5).

Then, the CPU of the IC card sets the write response status 5TS1 to "0" indicating the end of the write operation (step S6).

After that, 1. The CPU of the C card finishes the operation of the write routine and transmits the report data shown in FIG. 6(b) to the data terminal. Therefore, the data terminal determines the end of execution of the write routine by detecting the status 5TS1.

On the other hand, if the judgment result in step S3 is YES, the data exceeds the size of the record area, so the data from the application software is not written by setting "1" to the write response status 5TS2. (Step 57). Then, the CPU of the IC card finishes the data modification operation, and also finishes the write routine operation, and reports it to the data terminal. Therefore, by detecting the status 5TS2, the data terminal determines that the data from the application software has not been written to the IC card.

By the way, if the determination result in step S2 is No, the type of data specified by the application software is not recorded in the file of the IC card to be accessed, so a new write operation for the data is performed.

That is, first, the CPU of the IC card is activated.

An area for recording the data is secured in the file that the application software is trying to access (step S8).

Next, by executing the record management table update subroutine, the IC card's CPU adds a new index to the file record management table that the application software is trying to access, adding data indicating the type of data to be newly recorded. Record (step S9
).

That is, as shown in the flowchart of FIG. 10, first, the CPU-U of the IC card clears the flag CH (step 571).

Next, the IC card's CPU searches all data in the record management table of the file that the application software is trying to access, and determines whether the same type of data as specified by the application software exists in the record management table. (step 572).

If the judgment result is YES, an error occurred in the record management table update subroutine, and the flag CH should be set to "1".Step 573) IC card CP
tJ reports this to the data terminal. Therefore, by detecting the flag CH, the main program determines that the data in the record management table could not be updated.

On the other hand, if the determination result in step S72 is NO, the same type of data has not been recorded yet, so the CPU of the IC card creates a memory area for recording the type of data supplied from the application software in the record management table. Attempt to secure (step 574).

Then, the CPU of the IC card determines from the size of the record area of the directory whether there is any area left in the memory to record the data (step 575).

If the determination result is YES, there is an area for recording data in the record area in the memory of the IC card, so an index is added to the newly secured record area (step 576). At the same time, data regarding the newly created record area (for example, an offset value for creating a relative address) is recorded in the record management table (step 577). Here, the IC card CP
U finishes the operation of the record management table update subroutine and returns to the write subroutine.

On the other hand, if the determination result in step S75 is NO, the CPU of the IC card sets flag CH to "1" by executing step S73, since there is no area in the memory area of the IC card to record data. Here, I.C.
The card CPU finishes the operation of the record management table update subroutine and returns to the write subroutine.

In the write subroutine, the IC card's CPU
determines whether flag CH is set to "0" (step 510).

If the determination result is YES, the CPU of the IC card has successfully updated the data in the record management table, and thus creates a logical address for the data recording destination, as in step S4 (step 511).

Then, the CPU of the IC card records the data that the application software is attempting to write at the record position indicated by the logical address (step S12).

Then, the CPU of the IC card completes the new data write operation and executes step S6.
C card has write response status STS 1
Set "0" to "0".

Thereafter, the IC cart CPU finishes the operation of the write routine and reports this to the data terminal.

On the other hand, if the determination result in step S10 is NO, it means that the data in the record management table could not be updated.
The CPU of the C card sets "1" to the write response status 5TS2 by executing step S7.

Thereafter, the CPU of the IC card finishes the operation of the write routine and reports this to the data terminal.

Next, the operation order of the read subroutine will be explained using the flowchart of FIG.

First, the IC card's CPU searches the record management table by executing the record management table search subroutine to ensure that the type of data specified by the application software has been recorded in the file that the application software is trying to access. It is determined whether or not it has been set (step 531).

Next, the CPU of the IC card determines whether the flag SA is "1", that is, whether the data specified by the application software has already been recorded in the file that the application software is trying to access.
Step 532).

If the judgment result is YES, the data specified by the application software has already been recorded.
The C card creates a logical address for recording the data (step 533). The details have been explained in step S4 of the write subroutine and will therefore be omitted.

Next, the CPU of the IC card sets the data recorded at the logical address in a read format (step 534). At the same time, the IC card CPU sends 5T of the read response in order to notify the application software that the data read operation has been completed.
Set S3 to "0" (step 535).

After that, the CPU of the IC cart finishes the operation of the reading routine and reports this to the data terminal, while if the judgment result in step S32 is NO, that is, the data specified by the application software is not recorded. , the CPU of the IC card sets 5TS4 of the read response to "1" to notify the data terminal that the data could not be read (step 536).
). Thereafter, the CPU of the IC card finishes the operation of the read routine and reports this to the data terminal.

[Brief explanation of the drawing]

FIG. 1 is a complaint correspondence diagram of an IC card according to an embodiment of the present invention, FIG. 2 is a tree diagram showing the memory structure of the IC card, and FIG. 3 is a block diagram showing the file structure of each file of the IC card. Figure 4 is a block diagram showing the data format of the directory, Figure 5 is a block diagram showing the data format of the record management table, Figure 6 (a)
(b) is a block diagram excluding frames used when writing data, Figures 7 (a) and (b) are block diagrams showing frames used when reading data, and Figure 8 is the operating sequence of the write routine. 9th flowchart showing
10 is a flowchart showing the operation order of the record management table search subroutine, FIG. 10 is a flowchart showing the operation order of the record management table change subroutine,
FIG. 11 is a flowchart showing the operating order of the read routine. 1...Memory, 2...Data access means, 3...Record management table, 4...Address conversion means.

Claims (1)

[Claims] In an IC card equipped with a memory having a predetermined logical address space and data access means, there is provided a record management table that stores coded address information that specifies a record area to be used for each file. and address conversion means for creating a logical address based on the encoded address information when accessing the record area.