JPS636689A - Ic card - Google Patents

Abstract

PURPOSE:To reduce misdecision at the time of deciding whether a built-in memory is initialized or not by previously storing initializing deciding data in plural addresses previously selected in a memory and deciding the stored state. CONSTITUTION:At the time of initialization, the memory 111 is divided into 128 blocks each of which consists of 64 bytes, and data for deciding whether the memory is initialized or not are written in the leading addresses of respective 128 blocks. The deciding processing is executed by a microprocessor 112 of an IC card 11 e.g. At the time of the decision, the storing state of the deciding data in the memory 111 is decided to decide whether the memory is initialized or not.

Description

DETAILED DESCRIPTION OF THE INVENTION "Field of Industrial Application" The present invention relates to an IC card, and particularly to a configuration for determining whether or not a memory has been initialized.

"Prior Art" In recent years, so-called IC cards have been developed in which an IC chip such as a microprocessor or memory is incorporated into a card-like member. This IC card has an information processing function and has an excellent information storage capacity, so it is attracting attention as a card that can replace magnetic cards.

In such an IC card, the built-in memory is initialized before use. This initialization is generally done by
This is done by the microprocessor in accordance with a start command from the information processing terminal.

By the way, if the memory has already been initialized, it is necessary to avoid executing the initialization process.

This is because by executing the initialization process again, the data that has already been stored will be destroyed.

For this reason, the initialization program executed by the microprocessor is generally integrated with a determination program that determines whether initialization has been completed.

Conventionally, it has been determined whether the memory has been initialized by determining whether predetermined data is stored at one address selected above.

However, such a conventional determination configuration has a problem in that erroneous determinations are likely to occur. One of the causes of this is, for example, that the data in the memory is changed due to noise such as ultrasonic waves during the manufacture of the IC card.

"Problems to be Solved by the Invention" This invention was made to deal with the above situation, and when determining whether or not the built-in memory has been initialized,
It is an object of the present invention to provide an IC card that can reduce misjudgments as much as possible.

"Means for Solving the Problem" In order to achieve the above object, the present invention stores data for initialization determination at a plurality of addresses selected in advance on a memory, and upon determination, By determining the storage condition of the determination data in , it is determined whether or not the data has been initialized.

"Operation" According to the above configuration, even if the data stored in the memory can be changed due to noise or the like, the probability that all the data at the determination address will be changed is extremely low. Therefore, by determining whether the storage condition of the determination data at the determination address is within the permissible range,
Misjudgment can be reduced as much as possible.

Embodiment FIG. 1 is a block diagram of an IC card system shown to explain the configuration of an embodiment.

In the figure, 11 is an IC card. 12 is this IC
This is an information processing terminal for accessing the card 11.

The IC card 11 includes a memory 111 and a microprocessor 112 for accessing the memory.

FIG. 2 shows data stored in the initialized memory 111 according to the storage configuration of the memory 111. Note that in the figure, data is shown in hexadecimal.

In this embodiment, upon initialization, data for determining whether initialization has been completed is written to a plurality of addresses on the memory 111.

In the figure, "00" is data for this initialization determination. Now, the illustrated memory 111 has, for example, 64 bits EEP
If it is a ROM, the details will be described later, but this memory 111
is divided into 128 blocks of 64 bytes each during initialization. The above judgment data is written to the start address of each of these 128 blocks.

On the other hand, if the memory 11 has not been initialized, there is a very high probability that data other than [00], for example rFFJ, is stored at the determination address.

Therefore, in this embodiment, among the determination addresses, "OO
When there are more than a predetermined number of addresses storing data other than ", it is determined that the data has not been initialized." The reason why the number is set to be more than a predetermined number is to cope with the case where data changes due to accidental factors such as noise.

Note that the data r inserted at the final address of each block
Although the details will be described later, SUMJ is data indicating the sum check value of each block, and is also inserted at the time of initialization. Furthermore, data rFFJ is data written by erasing processing.

FIG. 3 is a flowchart showing the above determination process. The determination process shown in the figure is performed by the microprocessor 112 of the IC card 11, for example. The microprocessor 112 executes the program shown in FIG. 3 in accordance with a start command from the information processing terminal 12. First, step S
1 sets the specified address to 0. In other words, the start address of block 1 is specified. Further, a first counter that counts the number of blocks and a second counter that counts the number of addresses storing data other than rQQJ are each cleared. In the next step S2, data is read from the address specified in step S1. In the next step S3, it is determined whether the read data is roll, and if ro 0J, the process moves to step S4.

In step S4, the designated address is switched to the start address of block 2. In the next step S5, the count value N1 of the first counter is incremented by one.

In the next step S6, it is determined whether the count value N1 is 128 or not. If not, the process returns to step S2 and the same operation is repeated, and if it is 128, the determination process is ended.

- On the other hand, if it is determined in the previous step S3 that the data is not ro 0J, the process moves to step S7, and the count value N2 of the second counter is incremented by one. In the next step S8, it is determined whether the count value N2 is 10 or more. If it is less than 10, move to step S4 above,
Continue the determination process. - On the other hand, if it is 10 or more, it is determined that it has not been initialized, initialization is performed in step S9, and the determination process is ended.

Note that the initialization process executed in step S9 is as follows:
Some of the main items include the following:

(1) Check whether all addresses in the memory 11 have been erased, and if not erased.

(2) In order to make the memory 111 easier to access, the memory space is divided into 64 blocks as described above.

(3) To improve data reliability, perform a thumb check for each block, for example, and write the result to the final address of each block.

(4) Set the status necessary for the IC card function.

As described in detail above, in this embodiment, whether or not initialization has been completed is determined by observing data at a plurality of addresses on the memory 111, so that erroneous determination can be reduced as much as possible. In other words, even if the data changes due to accidental factors such as noise, it is unlikely that the data in all addresses for judgment will change. By appropriately setting the number of addresses that exist, it is possible to reduce erroneous determinations as much as possible.

Further, in this embodiment, since the addresses for determination are arranged at predetermined intervals, there is an advantage that the microprocessor 112 does not need to store the addresses for determination.

Furthermore, in this embodiment, initialization is executed immediately when a predetermined number or more of addresses storing data other than "00" are detected, thereby speeding up the determination process.

Although one embodiment of the present invention has been described in detail above, the present invention is not limited to this embodiment, and it goes without saying that various other modifications can be made.

For example, in the previous embodiment, a case has been described in which the determination addresses are arranged at regular intervals, but they may be arranged continuously. For example, 128 addresses of block 1.2 may be selected. Furthermore, the selection is not limited to the case where the selection is made according to a predetermined arrangement rule as described above, but the selection may be made at random.

Further, in the previous embodiment, the case where the determination is made on the IC card 11 side has been described, but it goes without saying that the determination may be made on the information processing terminal 12 side.

Furthermore, in the previous embodiment, the case where the judgment data is written to the memory that has been initialized is set, but it goes without saying that it may be written to the memory 111 that has not been initialized. be. In this case, for example, contrary to the previous embodiment, when there is a predetermined number or more of determination data,
It can be determined that it has not been initialized.

[Effects of the Invention] As described above, according to the present invention, it is possible to provide an IC card that can minimize erroneous determinations when determining whether or not the built-in memory has been initialized.

[Brief explanation of drawings]

FIG. 1 is a block diagram for explaining the configuration of one embodiment of the present invention, FIG. 2 is a diagram for explaining data stored in the memory of one embodiment, and FIG. 3 is an operation of one embodiment. It is a flowchart for explaining. 11...IC card, 12...information processing terminal, 11
1...Memory, 112...Microprocessor. Applicant's agent Patent attorney Takehiko Suzue Figure 1 Figure 2 Figure 3

Claims (1)

[Claims] A memory in which data for initialization determination is stored at a plurality of addresses, and whether or not the memory is initialized is determined based on the storage condition of the data for determination at the plurality of addresses. An IC card characterized by comprising: an initialization determination means.