JPH0283645A - Information card controller - Google Patents

Abstract

PURPOSE:To increase the amount of effective data to be stored in an information card by providing an error control means which performs the detection and correction of an error in storage data read from a memory in a card, and a means which performs the rewrite of error-corrected data on the memory. CONSTITUTION:An information card controller 2 is interposed between the host system of the information card 1, and a scramble processing means 22 applies scramble on data written on the memory 11 in the information card 1, and also, applies reverse scramble on the data read from the memory 11. A rewrite means 25 performs the rewrite of the error-corrected data on the memory 11 by an error control means 23. The error-corrected data to be rewritten, after being accumulated once in a data buffer 24, is written on the memory 11, then, the storage data in the memory 11 is updated. In such a way, it is possible to hold the data to be stored in the memory 11 in the information card 1 without increasing redundancy to a high level, and to increase the amount of effective data.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to an information card control device, and furthermore, to an EEPROM.
This relates to technology that is effective when applied to systems that read and write data stored in information cards with built-in rewritable memory, such as be.

[Prior Art] Recently, systems using information cards called IC cards have come into use in many fields.

In this type of system, E E
An information card control device 2' is used that mediates data exchange between an information card 1 having a built-in memory 11 such as a P-ROM and a host system (not shown). This information card control device 2' is a type of input/output terminal device, and includes an ink-face means (I/F) 21 that reads and writes data to the card 1, and a memory 11 on the card 1 side. It has an error control means 23 that performs error detection and error correction of read stored data, and sends error-corrected data as read output to the host side, while receiving data sent from the host side as write input. Write the data to the memory 1-1 on the card 1 side (for example, write the data to the memory 1-1 on the card 1 side (for example, "Nikkei Electronics December 28, 1987 issue,
437J, pages 46 and 47).

[Problems to be Solved by the Invention] However, the inventors have found that the above-mentioned technique has the following problems.

In other words, in conventional devices of this type, if there is an error in the data read from the memory 11 in the information card 1, as shown in FIG. 2, the error can be corrected and output. However, the data stored in the information card 1 and memory 11 could not be protected.

The memory 11 in the information card 1 contains, for example, EEP-R.
Although OM and the like are used, the data stored there gradually disappears over time.

If this data loss is left unchecked, the lost data will accumulate and eventually a time will come when error correction will no longer be possible.

One possible solution to the above-mentioned problem is to increase the redundancy of data stored in the memory 11 within the information card 1. Thereby, even if a large amount of lost data increases, error correction can be performed.

However, increasing the redundancy of stored data means
This requires an additional amount of storage capacity. In other words, another problem arises in that the amount of effective data that can be practically stored in the information card 1 decreases as the degree of redundancy increases.

Furthermore, even if the degree of redundancy is increased, the amount of lost data will eventually exceed the error correctable limit.

In other words, even if redundancy is increased, data loss itself cannot be prevented; it merely postpones the time when error correction is no longer possible.

An object of the present invention is to enable data stored in a memory within an information card to be stored permanently without significantly increasing its redundancy, so that data can be substantially stored in the memory within an information card. The purpose of the present invention is to provide a technology that increases the amount of effective data and also makes it possible to reliably protect the stored data contents.

The above and other objects and novel features of the present invention will become apparent from the description of this specification and the accompanying drawings.

[Means for Solving the Problems] Representative inventions disclosed in this application will be summarized as follows.

That is, an interface means for reading and writing data to an information card having a built-in memory; an error control means for detecting and correcting errors in stored data read from the memory in the card;
It has means for rewriting the error-corrected data into the memory in the memory.

[Operation] According to the above-described means, even if a part of the data stored in the memory of the information card is lost, correct data with the lost part restored by error correction can be written.

As a result, the data stored in the memory of the information card can be stored forever without increasing its redundancy, and the effective amount of data that can be stored in the memory of the information card The objective of being able to increase the number of people is achieved.

[Embodiments] Hereinafter, preferred embodiments of the present invention will be described with reference to the drawings.

In addition, in the figures, the same reference numerals indicate the same or corresponding parts.

FIG. 1 shows an outline of an information card control device according to an embodiment of the present invention.

The information card control device 2 shown in the same figure is an information card (C
The card is interposed between the card) 1 and the host system (not shown). Card interface means 21, scramble processing means 22, error control means 23, data buffer 24
, and rewrite control means 25.

The card interface means 21 reads and writes data to and from the memory (EEP-ROM) 11 built into the information card 1.

The scrambling processing means 22 scrambles the data written to the memory 11 in the information card 1 and descrambles the data read from the memory 11.

The error control means 23 detects and corrects errors in stored data read from the memory 11.

The data buffer 24 once multiplies the data written to the memory 11 by N.

The rewriting means 25 rewrites the data whose error has been corrected by the error control means 23 into the memory 11. Corrected data for rewriting is once stored in the data buffer 24 and then written to the memory 11 in the information card 1 via the scrambling processing means 22 and the card interface means 21. As a result, the data stored in the memory 11 is updated.

Further, the second rewriting means 25 monitors the operation of the error control means 23, and rewrites the error-corrected data to the memory 11 only when there is an error in the data read from the second memory 11. configured to write.

Regarding the information card control device configured as above,
The operation will be explained below.

First, when write data is sent from the host side, this write data is temporarily stored in the buffer 24 and then subjected to scrambling processing. The scrambled data is written into the memory 11 in the information card 1 by the card interface means 21.

Next, when there is a request to read data from the host side, the data stored in the memory 11 in the information card 1 is read via the card interface means 21. After the read data is descrambled by the scrambling processing means 22.

The error control means 23 checks whether there is an error.

Here, if it is determined that there is no error, the descrambled read data is directly sent to the host side as a read output.

On the other hand, if it is determined that there is an error, the error control means 2
3 performs error correction processing on the descrambled data. Then, the corrected data that has undergone this processing is sent to the host side as read output. At the same time, the rewrite control means 25 operates, and the corrected data corrected by the error control procedure 23 is temporarily stored in the buffer 24. The corrected data stored in the buffer 24 is then scrambled and sent to the memory 11 in the information card via the card interface means 21.
will be rewritten. As a result, the data stored in the memory 11 is replaced with new data whose errors have been corrected, from old data containing errors.

As described above, even if part of the data stored in the memory in the information card is lost, the lost part is restored by error correction and correct data is written.

As a result, the data stored in the memory 11 in the information card 1 can be stored for a long time without increasing its redundancy.
In addition to increasing the amount of effective data that can be substantially stored in the internal memory 11, it becomes possible to reliably protect the stored data contents.

Furthermore, in the embodiment described above, the rewrite control means 25
The device operates only when there is an error in the data read from memory 11 in card 1, and rewrites the error-corrected data to memory 11, but this prevents unnecessary rewriting operations. This can extend the life of the memory 11, such as an EEP-ROM, which has a limited number of write operations.

Although the invention made by the present inventor has been specifically explained above based on Examples, it goes without saying that the present invention is not limited to the above Examples and can be modified in various ways without departing from the gist thereof. Nor.

For example, date data may be stored in the memory 11 within the information card 1, and when this date data becomes older than a certain value, the data may be rewritten and new date data may be written.

The above explanation will mainly focus on the invention made by the present inventor in the EE field as a memory field, which is the background of the invention.
Although the case where the present invention is applied to a type of IC card with a built-in P-ROM has been described, the present invention is not limited thereto, and can also be applied to an information card that has a built-in static RAM or dynamic RAM as a memory backed up by a built-in battery. can.

[Effects of the Invention] The effects obtained by typical inventions disclosed in this application are briefly explained below.

In other words, the data stored in the memory inside the information card can now be stored for a long time without significantly increasing its redundancy, and the effective amount of data that can be stored in the memory inside the information card has increased. In addition to increasing the amount of information stored, the stored data contents can be reliably protected.

[Brief explanation of the drawing]

FIG. 1 shows an information car 1' jli according to an embodiment of the present invention.
control'! FIG. 2 is a block diagram showing the outline of a conventional information card control device. 1...Information card (IC card), il...Memory (EEP-ROM), 2...Information car 1-control device, 21...Card interface means, 2
2... Scramble processing means, 23... Error control means, 24... Data buffer, 25...
Rewriting control means.

Claims (3)

[Claims] 1. an interface means for reading and writing data to an information card having a built-in memory; an error control means for detecting and correcting errors in stored data read from the memory in the card; and error-corrected data. and means for rewriting the information into the memory within the card. 2. 2. The information card control device according to claim 1, further comprising scrambling processing means for scrambling data written to a memory built into the card and descrambling data read from said memory. 3. Claims 1 or 2 further comprising rewrite control means for rewriting error-corrected data into the memory only when there is an error in the data read from the memory built into the card. Information card control device.