JPH02156390A - Portable electronic device - Google Patents

Abstract

PURPOSE:To infer a state in which a data are stored by providing a portable electronic device with a data retention state judging means and a means to output the judge result of the judging means to an external part together with corresponding read out data. CONSTITUTION:When data are read out of a data memory 12 of card, instruction data having a prescribed format are inputted. When a corresponding area number exists, a control element 11 examines a corresponding record number. When the corresponding record number exists, the control element 11 calculates the exclusive OR or all the stored data in the corresponding record and compares the exclusive OR with a value calculated at writing time (BBC in the applicable record). When the compared result is noncoincidence, the control element 11 outputs the data to the external part together with a state signal to indicate abnormality in the retention state, and the device is returned to an instruction waiting state. According to the above-mentioned composition, it can be inferred in which state the data are stored, and the portable device can be obtained, which is especially effective when significant data are stored.

Description

Detailed Description of the Invention [Object of the Invention] (Industrial Application Field) The present invention provides an erasable non-volatile memory and a
An IC (
The present invention relates to a portable electronic device called an IC card that has a built-in integrated circuit chip, and particularly to a portable electronic device with an improved method of reading data from its memory.

(Prior Art) Recently, a so-called IC card has been developed as a new portable data storage medium, which has a built-in IC chip that has an erasable non-volatile memory and a control element such as a CPU that controls the memory. . This type of IC card is
The built-in control element accesses the built-in memory and inputs and outputs necessary data in response to external requests.

Conventionally, in such an IC card, when reading data from memory, if the data storage state is abnormal, a status indicating that the data storage state is abnormal is output to the outside. It was only. Therefore, there was a drawback that important data could not be read.

(Problem 8 to be solved by the invention) The present invention solves the problem that when reading data from the memory section as described above, if the data is stored in an abnormal state, the data cannot be read. An object of the present invention is to provide a portable electronic device that can read data from a memory section even if the data is stored in an abnormal state.

[Configuration of the Invention (Means for Solving the Problems) The present invention has a memory section for storing data, a control section for reading and writing data to this memory section, and selectively A portable electronic device for manually outputting data to and from an external device, comprising a determining means for determining whether the storage state of the data is normal or abnormal when reading data from the memory section, and a determination result of the determining means. and means for outputting the data to the outside together with the corresponding read data.

(Function) When reading data from the memory section, it is determined whether the storage state of the data is normal or abnormal, and this judgment result is output to the outside together with the corresponding read data. Even if the data storage status is abnormal,
The data can be read along with the status indicating that the storage state is abnormal. This makes it possible to infer what kind of data has been stored, which is especially effective when important data is stored.

(Example) Hereinafter, an example of the present invention will be described with reference to the drawings.

FIG. 8 schematically shows the configuration of an IC card as a portable electronic device according to the present invention, including a control element (control unit) 11 such as a CPU that controls the overall control, and a data memory.
(memory section) 12, a program memory 13, and a contact section 14 for electrically communicating with a terminal device (not shown), among which a control element 11, a data memory 2, and a program memory 1
3 is one IC chip (or multiple IC chips)
It is embedded within the IC card body.

The data memory 12 is used to store various data, and is composed of an erasable nonvolatile memory such as an EEPROM. The program memory 13 includes the control element 11
It stores control programs and the like, and is configured, for example, as a mask ROM.

The data memory 12 is largely divided into an area definition information storage section 15 and a data storage section 16, as shown in FIG. 7, for example. The data storage section 16 is a section for storing various data, and is divided into a plurality of data areas.

The area definition information storage section 15 stores area definition information and the like that define each data area of the data storage section 16.

The area definition information that defines one data area includes an area number that defines a number unique to the data area, position information that defines the position of the data area (for example, the start address of the data area), and the like.

Each data area of the data storage unit 16 includes, for example, a fifth
Records having the format shown in Figure (a) are stored. One record consists of stored data and a block check character (hereinafter abbreviated as BCC) obtained by calculating the exclusive OR (XOR) of the stored data.
It consists of Note that FIG. 5(b) shows a specific example of a record.

Fig. 6 shows how records are stored in a certain data area. Each record is stored sequentially from the beginning of the data area, and rlJ r2J "3"...
and a record number are assigned.

Next, the operation in such a configuration will be explained.

First, the record writing operation will be explained with reference to the flowchart shown in FIG. When writing a record to the data memory 12, write command data having a format as shown in FIG. 4 is input.

This write command data is composed of a write function code, an area number of the data area, a record number, and storage data.Now, when the write command data is input (Sl), the control element 11 It is checked whether a data area having an area number corresponding to the area number in the command data exists (S2, S3). As a result of this check, if the applicable area does not exist, the control element 11 outputs a status indicating that the applicable area does not exist (S4), and returns to the command data standby state. As a result of the above check, if the corresponding area exists, the control element 11 checks whether a record number corresponding to the record number in the write command data exists in the data area (S5 and S6).

As a result of this check, if the corresponding record number does not exist, the control element 11 outputs a status indicating that the corresponding record number does not exist (S7), and returns to the command data standby state. As a result of the above check, if the corresponding record number exists, the control element 11 writes the storage data in the write command data (S8). Then, the control element 11 calculates a value (B
CC) is written next to the stored data (S9) and returns to the instruction data standby state.

Next, the record reading operation will be explained with reference to the flowchart shown in FIG. When reading a record in the data memory 12, read command data having a format as shown in FIG. 2 is input. This read command data is composed of a read function code, an area number of a data area, and a record number.

Now, when read command data is input (S11), the control element 11 checks whether there is a data area with an area number corresponding to the area number in the command data (S12°813). . As a result of this check, if the applicable area does not exist, the control element 11 outputs a status indicating that the applicable area does not exist (514), and returns to the command data standby state. As a result of the above check, if the corresponding area exists, the control element 11 checks whether there is a record with a record number corresponding to the record number in the read command data (
515.316).

As a result of this check, if the corresponding record does not exist,
The control element 11 outputs a status indicating that there is no corresponding record (517), and returns to the instruction data standby state. As a result of the above check, if the corresponding record exists, the control element 11 reads out all stored data of the corresponding record (318). Then, the control element 11 calculates the exclusive OR (XOR) of all the read storage data.S19
) is compared with the value calculated at the time of writing (BCC in the corresponding record) (S20).

As a result of this comparison, if the two match (S21),
Along with the status indicating that the record storage status is normal,
Output the read data to the outside (522) and return to the command data standby state.

As a result of the above comparison, if the two do not match (S21)
, the read data is output to the outside along with the status indicating that the record storage state is abnormal (523), and the state returns to the command data standby state.

In this way, when reading data from the data memory, it is determined by the BCC whether the storage state of the data is normal or abnormal, and the result of this determination is output to the outside together with the corresponding read data. As a result, when important data such as bank balances and account numbers are stored, even if the data is stored in an abnormal state, it means that the storage state is abnormal when reading that data. The data can be read along with the status.

Therefore, it is possible to infer what kind of data has been stored, which is especially effective when important data is stored.

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.

[Effects of the Invention] As detailed above, the present invention provides a portable electronic device that can read data from a memory unit even if the data is in an abnormal state. can be provided.

[Brief explanation of the drawing]

The figures are for explaining one embodiment of the present invention, and FIG. 1 is a flowchart explaining a record reading operation, FIG. 2 is a diagram showing an example of the format of read command data, and FIG. 3 is a record writing operation. FIG. 4 is a diagram showing an example of the format of write command data, FIG. 5 is a diagram showing an example of the record storage format, FIG. 6 is a diagram showing how records are stored in the data area, and FIG. 7 is a diagram showing an example of the record storage format. FIG. 8 is a block diagram schematically showing the structure of the IC card. 11... Control element (control section), 12... Data memory (memory section) 13... Program memory, 1
5... Area definition information storage section, 16... Data storage section. Applicant's Representative Patent Attorney Takehiko Suzue

Claims (1)

[Claims] A portable electronic device having a memory section for storing data and a control section for reading and writing data to the memory section, and selectively inputting and outputting data to and from the outside. The device comprises a determining means for determining whether the data is stored in a normal or abnormal state when reading data from the memory section, and a means for outputting the determination result of the determining means to the outside together with the corresponding read data. A portable electronic device characterized by comprising: