JPS63239574A - Portable electronic device - Google Patents

Abstract

PURPOSE:To remove various troubles which are caused when program data is destroyed by providing a special circuit which checks the propriety of the program data. CONSTITUTION:The special circuit 14 is provided with a function for reading program data out of a program memory 13 in order, a function for judging the propriety of the read program data by using check codes in the program data, and a function for controlling whether or not a control element 11 can operate according to the judgement result. Thus, the circuit 14 is provided with those functions to accurately check the propriety of the data of the control program in the memory 13. Therefore, various troubles which are caused when program data is destroyed are removed and a high-reliability IC card is obtained.

Description

Detailed Description of the Invention [Object of the Invention] (Industrial Application Field) The present invention is applicable to non-volatile data memory and CP
The present invention relates to a portable electronic device called an IC card, which has a built-in IC (integrated circuit) chip having a control element such as a U.

(Prior Art) Recently, an IC card incorporating a nonvolatile data memory and an IC chip having an I11 control element such as a CPU 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 selectively inputs and outputs necessary data in response to a request from an external device.

The control element performs various controls using a built-in control program.

This control program is usually realized by storing program data as a mask pattern in a program memory constituted by a mask ROM when manufacturing the IC card.

Now, recent IC cards perform self-diagnosis immediately after starting up. This self-diagnosis was achieved by including a self-diagnosis program in the control program and executing the self-diagnosis program immediately after startup. However, this self-diagnosis is to check whether the IC card can operate normally, and mainly checks the operation of the RAM and registers in the control element, and does not check the validity of the program data. Therefore, if the program data is destroyed for some reason, various problems will occur. For example, among the program data, the data that makes up the interface part of the program has been destroyed, and even if the self-diagnosis shows that it is operational, there may be problems such as the inability to exchange data with external devices. Otherwise, various malfunctions may occur due to destruction of program data.

(Problems to be Solved by the Invention) As described above, the present invention does not check the validity of the data of the built-in control program, so if the program data is destroyed for some reason, various problems may occur. This was created to solve the problems that occur, and it is possible to accurately check the validity of all data in the built-in control program, thereby eliminating various problems that occur when program data is destroyed. The purpose is to provide a portable electronic device that is highly reliable.

[Structure of the Invention] (Means for Solving the Problems) The present invention has a data memory section and a control section for reading and writing data to the data memory section, and the control section A portable electronic device that has a program memory section that stores control program data for controlling the device, and that selectively performs input/output from the outside, and that reads the program data stored in the program memory section. a function to determine the validity of the read program data based on specific data present in at least one location in the program data; and a function to control whether or not the operation of the control unit is possible in accordance with the result of this determination. It has a special circuit with

(Function) By providing a special circuit for checking the validity of the program data as described above, it is possible to accurately check the validity of all the data of the built-in control program. Therefore, various problems that occur when program data is destroyed can be eliminated, and a highly reliable portable electronic device can be obtained.

(Example).

An embodiment of the present invention will be described below with reference to the drawings.

FIG. 5 shows an example of the configuration of a terminal device that handles an IC card as a portable electronic device according to the present invention. That is, this terminal device connects the IC card 1 to a card reader.
It is configured such that it can be connected to a control section 3 consisting of a CPU or the like via a writer 2, and a keyboard 4, a CRT display device 5, a printer 6, and a floppy disk device 7 are connected to the control section 3.

FIG. 1 shows an example of the configuration of an IC card 1, which includes a control element (for example, CPtJ) 11 as a control part, a nonvolatile data memory 12 whose storage contents can be erased as a data memory part, and a program memory part as a nonvolatile data memory 12. It consists of a program memory 13, a special circuit 14 as a program data check circuit for checking the validity of program data, and a contact section 15 for establishing electrical contact with the card reader/writer 2. The portion within the broken line (control element 11, data memory 12, program memory 13, special circuit 14) is composed of one IC chip and is embedded within the IC card body. The data memory 12 is used to store various data, and is composed of, for example, an EEFROM.

The program memory 13 is composed of, for example, a mask ROM, and as shown in FIG. etc., and is made up of multiple bytes of at least 2 bytes). Then, III! in the program memory 13! The l program has a data structure as shown in FIG. That is, the program data is divided into, for example, three areas A, B, and C, and the final byte of each ji is a check code (specific data) a, b, and c for checking data within the area. It is assumed that the program data in area A includes at least a program for realizing an initial response data sending routine and a self-diagnosis routine.

The special circuit 14 has a function of sequentially reading the program data in the program memory 12, a function of determining the validity of the read program data using a check code in the program data, and a function of determining the validity of the read program data according to the result of this determination! ! 31
It also has a function of controlling whether or not the operation of one element 11 is possible.

Next, the operation of such a configuration will be explained with reference to the diagram shown in FIG. Normally, the start-up sequence of an IC card is to release the reset after supplying power and clock from the card reader/writer 2. When power and clock are supplied, the control element 11 is in a reset state and does not operate. At this time, a reset signal, which is a starting control signal from the card reader/writer 2, is set to a predetermined level, and when the reset is released, only the special circuit 14 operates, and first the program data in area A of the control program is Check the validity of. That is, for example, program data in area A is read out and added sequentially, and validity is checked by checking whether the result matches check code a. If the result of this check is abnormal, the current state is maintained and the operation is terminated. If normal, the special circuit 14 releases the reset of the control element 11 and
Start. Then, by operating the self-diagnosis routine, the control element 11 first registers and R in the control element 11 used in the initial response data sending routine.
Check whether AM (for example, output buffer area for data transmission), etc. operates normally. As a result of this check, if there is an abnormality, the control element 11 self-stops its operation.

If normal, the control element 11 operates the initial response data sending routine to store the program memory 13.
Only the first byte (first byte) of the initial response data is sent to the card reader/writer 2.

Immediately after this, the control element 11 prompts the special circuit 14 to request restart. As a result, the special circuit 14 restarts, temporarily stops the operation of the control element 11, and then checks the validity of each program data in the remaining areas B and C in the same way as in area A. If the result of this check is abnormal, the current state is maintained and the operation is terminated. If normal, the special circuit 14 prompts the control cable 11 in the temporarily stopped state to request restarting. As a result, the control element 11 is restarted, and by operating the self-diagnosis routine again, it is checked whether the remaining registers, RAM, etc. in the control element 11 are operating normally. As a result of this check, if there is an abnormality, control element 1
1 self-stops operation. If normal, control element 11
By operating the initial response data sending routine again, all the remaining initial response data in the program memory 13 except for the first byte that has already been sent is sent to the card reader/writer 2.

After sending all the initial response data in this manner, the control element 11 enters a state in which it has command data from the card reader/writer 2. At this time, when command data is input from the card reader/writer 2, the control element 11 executes processing according to the command data, sends response data indicating the processing result to the card reader/writer 2, and then commands the card reader/writer 2 again. Return to data holding state.

In this way, the special circuit 14 is provided, and immediately after the reset is released,
This special circuit 14 checks the validity of the control program data in the program memory 13, and controls whether or not the 111110 element 11 operates according to the check result. All correctness can be checked accurately.

Therefore, various problems that occur when the program data is destroyed as described above can be eliminated, and a highly reliable IC card can be obtained.

In the above embodiment, an IC card is used as an example of a portable electronic device, but the present invention is not limited to a card-shaped device, and may be a block-shaped or pencil-shaped device, for example. Furthermore, the hardware configuration of the portable electronic device can be modified in various ways without departing from the spirit of the invention.

[Effects of the Invention] As detailed above, according to the present invention, the built-in Ill.
It is possible to accurately check the validity of all program data, thereby eliminating various malfunctions that occur when program data is destroyed, and providing a highly reliable portable electronic device. .

[Brief explanation of the drawing]

The figures are for explaining one embodiment of the present invention. The first factor is a block diagram showing the structure of the IC card, the second figure is a diagram showing the format in the program memory, and the third figure is a structure of program data. FIG. 4 is a flow chart explaining the operation, and FIG. 5 is a block diagram showing the configuration of the terminal iut. 1... IC card (portable electronic device), 2... Card reader/writer, 11... Control element (control unit),
12...Data memory (data memory section), 13...
・Program memory (program memory section), 14...
・Special circuit. Applicant's representative Patent attorney Takehiko Suzue Figure 1 Figure 2 Figure 3 Cause 4 (a) 4 rM (b) Figure 5

Claims (4)

[Claims] (1) A program memory section having a data memory section and a control section for reading and writing data to the data memory section, and storing control program data for the control section to perform control. A portable electronic device having a function of reading program data stored in the program memory section, and a function of reading out program data stored in the program memory section, and a function of reading out program data stored in the program memory section, and a function of reading out program data stored in the program memory section, and a function of reading out program data stored in the program data, A portable electronic device characterized by having a special circuit having a function of determining the validity of the read program data based on the data, and a function of controlling whether or not the control unit operates according to the result of this determination. . (2) The portable electronic device according to claim 1, wherein the special circuit operates immediately after receiving an external activation signal, and the control section does not operate at this time. (3) A patent characterized in that the special circuit grants operation permission to the control section only when the judgment result is positive, and prohibits the operation of the control section when the judgment result is negative. A portable electronic device according to claim 1. (4) The portable electronic device according to claim 1, wherein the specific data is a check code for program data in a specific range.