JPS623516B2 - - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to a write processing method for an IC card in which the write voltage applied to the IC card by an IC card processing device is controlled when writing information to the IC card. It is.

Cards with integrated circuits embedded in the card body are
It has come to be widely used in personal identification cards such as IC cards, credit cards, bank cards, and other fields. Moreover, the fields of its use are likely to expand further in the future. Such a card is herein referred to as an IC card, and an external device that performs processing such as writing and reading information to the IC card is referred to as an IC card processing device. The IC card is equipped with an integrated circuit such as an information processing circuit and a memory to store information, and is also equipped with input/output connection terminals for the integrated circuit. The storage element used as memory is a programmable read-only memory (PROM).
Different types of memory may require different voltage values. The type of PROM built into an IC card uses a destructive recording method that cannot be erased.
PROM, EPROM erasable by UV irradiation
(Erasable Programmable Read Only Memory)
Electrically erasable EEPROM (Electrically Erasable EEPROM)
Erasable Programmable Read Only Memory). The write voltage required to write information in these PROMs is gradually becoming lower due to the demand for higher density due to advances in technology and for the purpose of reducing power consumption. Therefore
The write voltage varies depending on the type of PROM,
In addition, as a result of improvements in the same type of devices as storage capacity increases, some devices have write voltages set lower than conventional products. For example, the write voltage of general-purpose PROMs currently on the market is shifting from 25V to 21V, and even lower-voltage products with built-in booster circuits that only require a 5V power supply are being developed. . These PROMs
When an IC card is used with various types of built-in devices depending on its purpose, the write voltage is applied to the PROM built into the IC card when storing information.
There may be cases where the
Problems such as PROM destruction may occur. When writing information to a PROM, the write voltage may require a specific voltage depending on the type of PROM. ICs with different built-in PROMs
When a variety of cards are used, the voltage for writing information may also vary depending on the IC card. If a voltage exceeding the allowable range of the rated value of the PROM built in the IC card is applied,
The built-in PROM may be destroyed and the information previously stored may become invalid.
If the write voltage did not reach the allowable range of the rated voltage value, there was a risk that information would not be written to the PROM or that incorrect information would be written.

In order to solve the above-mentioned drawbacks, this invention determines the appropriate write voltage unique to the built-in PROM and applies it to each IC, thereby accidentally causing a voltage that exceeds the allowable range of the rated voltage value of the write voltage. This makes it possible to prevent the built-in PROM from being damaged by applying voltage, or from being unable to write information to the PROM due to a voltage that is less than the rated voltage being applied, or from writing errors. different
An object of the present invention is to provide a writing processing method for an IC card, which enables processing of various types of IC cards with built-in PROMs. This invention will be explained below.

FIG. 1 is a schematic block diagram of a card processing device including an IC card, for explaining one embodiment of the present invention. In this figure, A is an IC card, B is an IC card processing device, 1 is an IC section consisting of a CPU section and a PROM, 2 is an I/O line, 3 is a reset signal line, 4 is a crystal signal line, and 5 is an IC section consisting of a CPU section and a PROM. teeth
The power supply line for the write operation voltage V _PP to the PROM, 6 is
Power supply line for read operation voltage V _CC of CPU, 7 is ground, 8 is I/O port and controller section, 9 is write operation voltage generation circuit, 10 is voltage control section, 11
12 represents a keyboard portion, 12 represents a data processing portion, and 13 represents a monitor portion.

Next, the operation will be explained. IC card A is IC
After being set in the card processing device B, the operating voltage V _CC of the CPU is applied and input to the crystal signal line 4, and then when an input is applied to the reset signal line 3, the operation of the IC card A is started. After the operation of IC card A, the first thing to do is to use the
Outputs PROM proper write voltage value information to IC card processing device B.

The IC card processing device B determines this input write voltage value information, and outputs a signal based on the determination result from the controller to the write operation voltage generation circuit 9, so that an appropriate write voltage is applied to the operating IC card A. generated. Next, input the processing mode into IC card processing device B, and send this mode signal from the I/O port and controller section 8.
Output to IC card A. The IC card A that receives the mode signal discriminates this mode signal and performs processing in the processing mode.

Figures 2 and 3 show an embodiment of the method of writing to an IC card according to the present invention.
This is a flowchart for explaining the operation of the IC card processing device B, and FIG. 3 is a flowchart for explaining the operation of the IC card A. Figures 2 and 3
In the figure, ~, ~〓 indicate each step.

First, FIG. 2 will be explained. After the operation starts (), the write voltage value information is input (), the write voltage is determined (), the command key is pressed (), and the command is set to read mode R.
or write mode W is determined ().

In case of read mode R, IC card processing device B
After outputting the read mode signal (), the status information stored in the PROM of the IC card A is read out and output to the IC card processing device B, and after completion, it waits for a mode input. IC card processing equipment B
Now, input the data output from the IC card A (), process the data (), display it on the monitor unit 13 (), and after completion (), enter the command key-in state (). Also, light mode W
In the case of , IC card processing device B outputs a write mode signal (), inputs it from the keyboard section 11 (), processes the input information (), and then outputs data to IC card A (). , enter the information with IC card A and PROM
Write to. The necessary write voltage at this time is controlled by the IC card processing device B so that it is applied to the IC card A at an appropriate time for writing (). In this flowchart, after the information has been written (), the data can be read and confirmed. in this way
By outputting the write voltage value information specific to PROM built in IC card A to the outside, IC
It becomes possible to apply an appropriate write voltage to each card A. Also, in the unlikely event that an inappropriate high voltage is applied.
If there is a risk that IC card A will be charged,
To prevent destruction of an IC card A due to writing in an IC card processing device B. In addition,
indicates the end.

Next, FIG. 3 will be explained. After the operation starts (), IC card A outputs write voltage value information (), and mode input is performed from IC card processing device B (〓), and the mode is set to read mode R.
or it is determined from the light mode W (). In case of read mode R, PROM in IC card A
Outputs the information stored in the data (〓),
When it is finished, return to mode input (〓). In addition, in the case of light mode W, the necessary data
Since it is sent from IC card processing device B, write the data (〓). When the writing is completed, the read mode R is set and the written data is confirmed (〓).

As shown in the above embodiment, a specific area is provided in advance at the beginning of the PROM storage area, and by storing write voltage value information specific to that PROM in this specific area, an external The device can be used to determine the appropriate write voltage. In other words, when using IC card A, after the IC card A starts operating, before reading stored information or writing new information,
By reading the write voltage value information stored in a specific area provided at the beginning of the PROM and outputting it to an external device, the appropriate write voltage for this IC card A can be selected from the information input by the external device. I can do it. This makes it possible to reliably prevent errors in writing information, inability to write, and destruction of the PROM due to incompatibility of the write voltage with respect to the PROM built in the IC card A.

In addition, when IC cards A are produced in large quantities using the same combination of elements, storing the write voltage value information in the PROM is time-consuming and requires an extra process, so the microcomputer controls the A similar result can be obtained by providing the program with a function to output write voltage value information without storing it in the data storage PROM as described above. be able to. In particular, if the data storage PROM is electrically erasable and is a batch erase type EEPROM, it becomes necessary to erase the information stored in this EEPROM when transaction data overflows or an error occurs. Even in such a case, the write voltage value information will not be erased, making it an effective means.

As explained above, the present invention provides an IC card with a means for outputting write voltage value information necessary for writing to the outside, and an IC card processing device.
We have provided a means to select the write voltage based on the write voltage value information from the IC card, and we have used these to perform the write process, so we can prevent PROM destruction, write errors, or write failure due to information write operations. In addition to reliably preventing malfunctions, it also enables IC cards with built-in PROMs that require different write voltages to be used together in the same IC card processing device, making it possible to use new write voltages expected in the future. It has the advantage of being able to provide an IC card system that can respond to changes.

[Brief explanation of the drawing]

FIG. 1 is a block diagram of an IC card processing device including an IC card for explaining the method of writing to an IC card according to the present invention, and FIGS. 2 and 3 each illustrate an embodiment of the present invention. This is a flowchart of the method. In the figure, A is an IC card, B is an IC card processing device, 1 is an IC section consisting of a CPU section and a PROM, 2 is an I/O line, 3 is a reset signal line, 4 is a crystal signal line, and 5 is a connection to the PROM. Power line for write operation voltage, 6 is power line for CPU read operation voltage, 7 is ground, 8 is I/O port and controller section, 9
10 is a write operation voltage generation circuit; 10 is a voltage control section;
11 is a keypad section, 12 is a data processing section, 13
is the monitor section.

Claims (1)

[Claims] 1. A method for writing to an IC card, which has an integrated circuit including an active element, a memory element, etc. for processing electrical signals, and is equipped with input/output connection terminals for the integrated circuit. Means for outputting write voltage value information necessary for writing to an IC card processing device is provided in the IC card, and on the other hand, the write voltage value information output from the IC card by the IC card processing device A write processing method for an IC card, characterized in that a write voltage corresponding to the write voltage value information is applied to the IC card, and a write voltage that does not correspond to the write voltage value information is not applied to the IC card.