JPH09297830A - Ic card - Google Patents

Abstract

PROBLEM TO BE SOLVED: To shorten the wait time at the time of resetting of the IC card, and reduce the influence of a defect that a nonvolatile data storage means has after data writing. SOLUTION: A CPU 1 which executes a program stored in a ROM 2 performs a diagnostic process for a ROM 2, a diagnostic process for an EEPROM 4, and a repairing process for the EEPROM 4 only when receiving a self-diagnostic process command. Further, the CPU 1 diagnoses the SUM of respective sectors constituting a data storage area of the EEPROM 4 and connection information on the order of the respective sectors through the diagnostic process for the EEPROM 4, and repairs the SUM and connection information through the subsequent repairing process. Further, the CPU 1 determines the mode of the repair in the repairing process for the EEPROM 4 according to the parameters of the command and performs the repairing process in the corresponding mode.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an EEPROM or F
The present invention relates to an IC card that divides a non-volatile data storage unit such as a RAM into a plurality of sectors and stores files across the plurality of sectors and that prevents the IC card from becoming unusable due to memory failure.

[0002]

2. Description of the Related Art Conventionally, an IC card having a function of detecting a memory defect has been developed. For example, the file control information (for example, directory information) stored in the specific area of the non-volatile data storage unit is checked immediately after reset, and if the check result is an error, the external device (upper system) is checked. There is an IC card that returns data indicating that an error has occurred in the information. Also, I
There is also a card in which a SUM for checking is added to the program code stored in the PROM after the activation of the C card, and the program code is checked immediately after resetting.

There is also an IC card having a function of detecting a defect in the nonvolatile data storage means and automatically repairing the defect. In this type of IC card, the defective sector is locked as unusable so that the entire IC card is not disabled even if a defect occurs in a certain sector of the nonvolatile data storage means, and the defective sector is skipped to write data. Is being processed. The data written in this way is automatically skipped over the locked unusable sectors and is read so as to be correctly contiguous.

[0004]

By the way, in recent years, RA
The reliability of semiconductor devices such as M, PROM, EEPROM, and FRAM has been extremely improved, and it is no longer necessary to check each reset process as before. However, in the conventional IC card, both the directory information check process and the program code check process are automatically and forcibly performed immediately after reset as described above.

Of course, the above check may be carried out every reset, but during the check process, the external device sends a reply (ATR: Answer To Re) from the IC card.
turn). Processing is always delayed for a considerable amount of time just to confirm whether or not there is a memory defect with a very low probability of occurrence. Further, in the conventional IC card which locks the defective sector of the non-volatile data storage means at the time of writing data, when a memory defect occurs after writing the data, this defective sector cannot be locked and skipped, and the defective sector concerned. Subsequent data cannot be read normally.

The present invention has been made under such a background, and it is possible to reduce the waiting time at the time of resetting and to reduce the influence of a defect generated in the non-volatile data storage means after data writing. Is intended to provide.

[0007]

In order to solve the above-mentioned problems, the invention according to claim 1 is the first non-volatile data storage means for storing a program, and the second non-volatile data for storing the data. A storage unit, a communication unit that transmits and receives data to and from an external device, and a command received via the communication unit based on a program stored in the first nonvolatile data storage unit, and An IC card comprising a processing means for transmitting an execution result of an instruction to the outside via the communication means, wherein the processing means is described in a program stored in the first non-volatile data storage means. Also, a diagnostic process for the first non-volatile data storage means, a diagnostic process for the second non-volatile data storage means, and a repair process for the second non-volatile data storage means. Among them, it is characterized in that selecting executing processing corresponding to commands received via the communication means.

According to a second aspect of the present invention, in the first aspect, the second non-volatile data storage means is composed of a plurality of sectors, and data is continuously stored in the plurality of sectors. In this case, the sector includes real data and diagnostic data corresponding to the real data, and the processing unit selects the restoration process of the second non-volatile data storage unit to execute real data and diagnostic data. It is characterized by resetting the diagnostic data of a sector whose correspondence with the data is abnormal.

Further, the invention according to claim 3 is the invention according to claim 2.
In the described one, the sector includes actual data, connection information indicating the order of the sectors, and actual data and diagnostic data corresponding to the connection information, and the processing means includes the actual data, the connection information, and the diagnostic data. While diagnosing the consistency of the connection information of the sector whose correspondence with is normal,
The diagnostic result is transmitted to an external device via the communication means.

Further, in the invention according to claim 4, in the invention according to claim 2, the sector includes real data, connection information indicating an order of the sectors, and real data and diagnostic data corresponding to the connection information. In addition, the processing means diagnoses the consistency of the connection information of the sector for which the correspondence between the actual data and the connection information and the diagnostic data is normal, and the result of this diagnosis is not consistent. It is characterized in that the connection information of the sector is restored and the diagnostic data of the sector is reset.

[0011]

An embodiment of the present invention will be described below with reference to the drawings. FIG. 1 is a diagram showing a configuration of an IC card according to an embodiment of the present invention. In the figure, reference numeral 1 denotes a CPU (Central Processing Unit), which is a ROM (Read Only Memo) storing a program executed by the CPU 1.
ry) 2, a RAM (Random Access Memo) used as a temporary storage area for command data, a work area for the CPU 1, etc.
ry, volatile memory) 3, EEPROM (Electrically Er
asable Programmable ROM) 4 via a bus of a predetermined width. The CPU 1 has a Vcc (power supply voltage) supplied from an IC card terminal section (communication means) (not shown),
A program stored in the ROM 2 is read out and executed based on the RST signal (reset signal) and the CLK signal (clock signal) to write and read data to and from the RAM 3 and the EEPROM 4, and I / O.
Data (represented by I / O in the figure) is transmitted / received to / from an external device via the interface.

The ROM 2 (first non-volatile data storage means) is a mask ROM or PROM (Programmable
ROM) and EPROM are used to store a desired program in advance. Further, although the configuration in which the EEPROM 4 is used as the second non-volatile data storage means is shown, the present invention is not limited to this, and the non-volatile data storage means is configured by combining an SRAM (Static RAM) with a battery, for example. It may be used as a data storage means or FRAM.
(Flash RAM) may be used. ROM2, RA
The data storage areas of the M3 and the EEPROM 4 are hereinafter referred to as a ROM area, a RAM area and an EEPROM area, respectively.

The IC card having the above structure is normally accessed by a computer connected to the IC card reader / writer while being inserted into the IC card reader / writer. In the present specification, the IC card reader / writer and the computer are referred to as an external device.

Next, the processing performed by the IC card having the above configuration will be described. However, in the following description, if the main body of processing is omitted, the CPU 1 is the main body. The IC card is activated by receiving the RST signal in the state where the Vcc and CLK signals are supplied, and sends the ATR information (ISO 7816). After the activation, the data block (command or the like) transmitted from the external device is processed as shown in FIG.

FIG. 2 is a flow chart of access processing in the IC card, and as shown in this figure,
In step SA1, standby processing is performed until the data block transmitted from the external device is received. When the data block is received, it is determined whether or not the data block is in the correct format (steps SA2 and SA3), and when it is determined that the format is correct, the command included in the data block is processed ( Step SA4),
A response including the processing result is returned to the external device (step SA5). On the contrary, if it is determined in steps SA2 and SA3 that the format is not correct, error processing is performed (step SA6) and a response indicating that the format is not correct is returned to the external device (step SA).
5). The communication control between the IC card and the external device may be performed in the above-described block unit or in character units. In short, it suffices if it is in block units at the stage of step SA2.

FIG. 3 is a flow chart showing the processing of the self-diagnosis processing command, and the processing shown in this figure is as shown in FIG.
In, the process corresponds to the process of step SA4 when the received data block includes the self-diagnosis process command. In the processing of the self-diagnosis processing command, first, the ROM 2
It is determined whether to check the program code stored in (step SB1). This judgment is made based on the switch (parameter) added to the command. Here, the format of the self-diagnosis processing command will be described with reference to FIG.

FIG. 9 is a diagram showing an example of the format of the self-diagnosis processing command used in this embodiment. The self-diagnosis processing command in this example is a reserved word "CHECK" followed by an optional parameter P1. , P2. The parameter P1 can take the values 00, 01, 02,
These respectively mean a check process of the ROM 2, a check process of connection information of the EEPROM 4, and a repair process of the EEPROM 4 (described later). The parameter P2 represents the mode of the repair process, and can take the values 00 and 01, which means the forced repair process and the normal repair process, which will be described later, respectively. So, for example, "CHEC
The command "K / 00" is processed as a command for performing only the checking process of the ROM2. Each parameter can be omitted. In this case, when the parameter P1 is omitted, the checking process of the ROM2 and the parameter P2 are performed. When is omitted, the normal repair process is set to be processed as selected.

In the checking process of ROM2, RO
The program code stored in M2 and a SUM check (total check) code (hereinafter referred to as SUM) added to the program code as diagnostic data are added from address 0 to the final address (step SB2 in FIG. 3), It is determined whether or not the total is zero. The SUM is a ROM
Since the data from 0 to the final address of 2 are written in the ROM 2 in advance so that the total is 0, the above total is always 0 unless the ROM 2 has a memory defect.

When the total of the addresses 0 to the final address of the ROM 2 is 0, that is, when the ROM 2 is determined to be normal, a response indicating that the check process is normally completed is generated (steps SB3 and SB4). . On the other hand, if the above total is not 0 and it is determined that a memory failure has occurred in the ROM 2, a response (error response) indicating that the check processing has ended abnormally is generated (step SB).
3, SB5). The response thus generated is returned to the external device in step SA5 of FIG.

When it is determined in step SB1 that the parameter P1 is not 00 and the check processing of the ROM2 is not performed, the connection information stored in each sector of the EEPROM 4 is checked (step SB).
6). The connection information check processing is the processing shown in FIG. 4, but here, first, in FIG. 8A and FIG. 8B.
The data structure of the EEPROM 4 will be described with reference to FIG.

FIGS. 8A and 8B are diagrams conceptually showing the data structure of the EEPROM 4, respectively.
In these figures, hexadecimal notation 00, 01, ..., F
The rows numbered F correspond to the sectors in the EEPROM area, and each sector has an actual data area, a front sector area, a rear sector area, and a SUM area. The actual data area is the data entity such as a file, the front sector area is the sector number immediately before the sector (hereinafter referred to as the front sector number), and the rear sector area is the sector immediately after the sector. A number (hereinafter referred to as a rear sector number) is stored, and the front sector number of the first sector and the rear sector number of the last sector are both 00. The front sector number of the head sector may be FF, and the EEPROM area may be formed in a ring shape. Further, in the SUM area, a SUM whose sum of the data substance of the sector, the front sector number, and the rear sector number is 0 is stored.

Next, with reference to FIG. 4, a process for checking the connection information in the EEPROM area will be described. First,
In step SC1, the command is analyzed to determine whether or not the repair process should be performed, that is, whether or not the parameter P1 is 02. When the connection information check process is performed, the command is "CHECK / 01", and thus the process proceeds to step SC2. In step SC2, 00 is substituted into the variable FSCT representing the previous sector number, and 01 is substituted into the variable SCT representing the sector number of the treatment target (hereinafter referred to as the current sector number). Then, "current" indicating the current position of the read pointer in the EEPROM area
If is not 01, the current is substituted into the variable SCT (steps SC3 and SC4). Thus, the initial setting is completed.

Next, the processing of steps SC5 to SC11 is repeated until the conditions described later are satisfied. First, the reading process is performed on the current sector represented by the variable SCT (01 sector here) (step SC5). As shown in the flowchart of FIG. 5, this read processing reads all the data in the current sector onto the RAM area (step SD1), and SUMs the read data.
This is a process of performing a check process (step SD2).

Next, in step SC6, step SD
It is determined whether or not the SUM error is detected in the SUM check process of No. 2, and when the SUM error is not detected, that is, the correspondence between the data entity in the current sector, the previous sector number, the rear sector number, and the SUM is normal. Connection information in the current sector, that is, RAM
A connection information confirmation process is performed based on the front sector number and the rear sector number on the area (step SC7). In this confirmation processing, as shown in the flowchart of FIG. 6, when the previous sector number on the RAM area and the variable FSCT match, the value of the variable SCT is substituted into the variable FSCT (step S
E1, SE2), and if they are not equal, information indicating that a connection error has been detected is written in a specific area of the RAM area (steps SE1, SE3).

Since the variable FSCT stores a value (here, 00) which should be the previous sector number, if the previous sector number of the current sector is not 00, a connection error occurs.
In step SE2, the variable FSCT is set to the variable SC.
The value of T is substituted in order to prepare for the next loop. For example, the value of the variable FSCT changes from 00 to 01.

Next, at step SC9, the variable NSCT
The rear sector number on the RAM area is substituted into. Then, if a connection error is detected in the diagnostic processing in step SC7, the rear sector number in the RAM area is substituted into the variable SCT (step SC10), and the value of the variable NSCT is 0.
If not, the process returns to step SC5. However,
Here, FSCT = 01, SCT = 02. The processes of steps SC5 to SC11 are repeated until the value of the variable NSCT becomes 0 in step SC11, and when the value becomes 0, the connection information check process ends.

On the other hand, when a SUM error is detected in the above loop, that is, when the correspondence between the data entity, the previous sector number, the subsequent sector number, and the SUM in the current sector is abnormal, information indicating that fact is given. RA
The data is written in the specific area of the M area, and the connection information check processing is ended (step SC12). 8 (a) and 8
In the example of (b), FSCT = 02, SCT = 03, NSC
The process ends in the state of T = 03. If a connection error is detected in the above loop, the information indicating that is written in a specific area of the RAM area, and the connection information check process ends (step SC12). As a case where the SUM error does not occur and the connection error occurs, for example, the ** part in FIG. 8A and FIG. 8B and the defective part of the actual data area do not accidentally generate the SUM error. There is a case where there is a change, and in the example of FIG. 8A, FSCT = 02, SCT = 03, NSCT = 04.
8B, in the example of FIG. 8B, FSCT = 03, SCT
= 03, NSCT = **, the process ends. Then, the process returns to step SA5 of FIG. 2, and the diagnosis result in the connection information check process (the RAM at each point of the above process)
A response based on the information written in the specific area of the area) is returned to the external device.

By the way, the parameter P1 of the command is 0
If it is 2, the repair process of step SC14 of FIG. 4 is performed. This repair processing is performed by issuing a command again after the above-mentioned connection information check processing, and each variable value at the end of the previous check processing is stored in the RAM.
Has been maintained on the area. Hereinafter, the restoration process will be described with reference to the flowchart of FIG.

First, in step SF1, the variable SCTN is changed.
To 0. Next, a sector whose previous sector number matches the SCT (current sector number) is searched, and the number of the hit sector is substituted into the variable SCTN (step SF2).
When the number of hit sectors is one, the value of the variable SCTN is reset to the sector number after the sector represented by SCT (steps SF3 and SF4).

Next, in step SF5, the variable SCTF is set.
To 0. Then, a sector whose rear sector number matches the SCT (current sector number) is searched, and the number of the hit sector is substituted into the variable SCTF (step SF
6). If only one sector is hit, SC
The value of the variable SCTF is set to the sector number before the sector represented by T (steps SF7 and SF8).

For example, in the example of FIGS. 8 (a) and 8 (b), the repair process is started in the state of SCT = 03, the sector with the previous sector 03 is searched, and as a result, the sector number is 04.
Only the sectors of are extracted. Sector number 04 is SCTN
, And the sector number is set as the subsequent sector number of the sector of 03. Then, the sector having the subsequent sector of 03 is searched, and as a result, only the sector having the sector number of 02 is extracted. The sector number 02 is substituted into the SCTF and set as the previous sector number of the sector whose sector number is 03. After the connection information is restored through the above process, the SUM of the current sector represented by the variable SCT is recalculated (step SF9), the SUM of the current sector is reset (step SF10), and finally the data verification ( (Verification) is performed (step SF11).

By the way, when there are a plurality of hit sectors in each search process, it is judged whether or not the forced repair process is designated (steps SF12, SF1).
3) If forced repair is designated, the process of steps SF4 and SF8 and subsequent steps is performed using the sector number of the last hit sector, that is, the current value of SCTN. On the other hand, if the forced repair is not designated, it cannot be determined which sector number should be used for the repair, so that only the information indicating that the repair has failed is written to the specific area of the RAM area (step SF14). Then, the process returns to step SA5 in FIG. 2, and as in the case of the connection information check process,
A response based on the information written in the specific area of the RAM area is returned to the external device.

As described above, according to the embodiment of the present invention, the ROM area check processing, the EEPROM area check processing, and the EEPROM area repair processing are commandized and can be executed at any time. The waiting time can be shortened as compared with the conventional one in which various processes are executed at the time of reset. Even if a defect occurs in the EEPROM area after writing the data, the SU
By resetting M, the effect does not affect subsequent data.

Further, even if an error occurs in the connection information itself, it can be reproduced from the connection information before and after.
Further, since the forced repair and the normal repair can be selected, it is possible to surely avoid the data destruction due to the careless repair, and it is possible to perform the repair processing according to the situation.

[0035]

As described above, according to the present invention,
At the time of resetting, the first non-volatile data storage means diagnostic process, the second non-volatile data storage device diagnostic process, and the second non-volatile data storage device repair process can be selectively executed by an instruction from an external device. The required time can be shortened as compared with the case where it is always executed (Claim 1).

Further, in the second non-volatile data storage means, since the diagnostic code is included in the sector and is repaired, the influence on the succeeding sector can be suppressed (claim 2). Further, by diagnosing the connection information, it is possible to reliably detect the memory failure in the second nonvolatile data storage means (claim 3). Further, by repairing the connection information, it is possible to suppress the influence on the subsequent sector (claim 4).

[Brief description of drawings]

FIG. 1 is a diagram showing a configuration of an IC card according to an embodiment of the present invention.

FIG. 2 is a flowchart of an access process in the IC card.

FIG. 3 is a flowchart showing an example of a self-diagnosis process for the IC card.

FIG. 4 is a flowchart showing a process of checking connection information with respect to the EEPROM 4 of the IC card.

FIG. 5 is a flowchart showing a sector read process from the EEPROM 4;

FIG. 6 is a flowchart showing a process of reading connection information from the EEPROM 4.

FIG. 7 is a flowchart showing a repair process for the same EEPROM 4.

FIG. 8 is a diagram conceptually showing the data structure of the EEPROM 4.

FIG. 9 is a diagram showing an example of a format of a repair command received by the IC card.

[Explanation of symbols]

1 ... CPU, 2 ... ROM, 3 ... RAM, 4 ... EEPRO
M.

Claims (4)

[Claims] 1. A first non-volatile data storage means for storing a program, a second non-volatile data storage means for storing data, a communication means for transmitting and receiving data to and from an external device, and the first non-volatile data storage means. And a processing means for executing the command received via the communication means based on the program stored in the non-volatile data storage means and transmitting the execution result of the command to the outside via the communication means. An IC card, wherein the processing unit is a diagnostic process for the first non-volatile data storage unit described in the program stored in the first non-volatile data storage unit, the second non-volatile storage unit. Diagnostic processing for data storage means, and the second
Among the restoration processing of the non-volatile data storage means, a processing corresponding to an instruction received via the communication means is selectively executed. 2. In the case where the second non-volatile data storage means is composed of a plurality of sectors, and the data is continuously stored in the plurality of sectors, the sector corresponds to the real data and the real data. The diagnostic data of the sector in which the correspondence between the actual data and the diagnostic data is abnormal due to the selective execution of the restoration process of the second non-volatile data storage means. The IC card according to claim 1, wherein the IC card is reset. 3. The sector includes real data, connection information indicating the order of the sectors, and real data and diagnostic data corresponding to the connection information, and the processing unit includes the real data, the connection information, and the diagnostic data. 3. The IC card according to claim 2, further comprising: diagnosing the consistency of the connection information of the sector whose correspondence relationship is normal, and transmitting the diagnosis result to an external device via the communication means. 4. The sector includes real data, connection information indicating the order of the sectors, and real data and diagnostic data corresponding to the connection information, and the processing unit includes the real data, the connection information, and the diagnostic data. And the consistency of the connection information of the sector for which the relationship with is normal is diagnosed, the connection information of the sector for which the consistency is not found in this diagnosis result is restored, and the diagnostic data of the sector is re-established. The IC card according to claim 2, wherein the IC card is set.