JPH1027231A - Ic card - Google Patents

Abstract

PROBLEM TO BE SOLVED: To transmit long data at one time without being limited by the capacity of the RAM of an IC card by providing a means for storing the length of a transmission buffer, the means for storing a maximum transmission block length and the means for storing the length of non-transmitted data in one block. SOLUTION: This IC card 1 respectively writes the length of the transmission butter 21 of the IC card 1 to a transmission buffer length storage part 31 and the reception butter length of a terminal to a maximum transmission block length storage part 32 prior to the reception of a read command from the terminal. When the IC card 1 receives the read command sent out from the terminal, a chaining control part 3 writes the byte number of data not read yet to an entire remaining data length storage part 33. Also, the chaining control part 3 writes the maximum transmission block length to a transmission block remaining data length storage part 34. When the storage of values to the respective storage parts is ended, a processing part 4 reads the data stored in a nonvolatile memory 5.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an IC card having at least a memory, and has a function of managing a transmission state of data stored in the memory.

[0002]

2. Description of the Related Art A chip built in an IC card must be reduced in external dimensions in order to avoid stress concentration and to maintain the strength of the chip itself due to an external load caused by bending or the like. Is required. To reduce the size of the chip, the capacity of the RAM built into the chip of the IC card is
Generally, it is smaller than the RAM capacity of the terminal. Therefore, when transmitting data from an IC card to a terminal, it is necessary to divide the data into a plurality of blocks to be transmitted from the IC card and transmit the data using a function called chaining.

For example, when the data length that can be transmitted by an IC card at a time is 100 bytes, to transmit 400 bytes of data from the IC card to the terminal, the data is divided into four blocks every 100 bytes and transmitted. FIG. 3 shows a data transfer sequence between the terminal and the IC card at this time. When the IC card finishes transmitting one block, the terminal transmits a continuous data request block instructing the next block to be transmitted to the IC card. Thus, each time the IC card finishes transmitting data, it is necessary to send a continuous data request block from the terminal.

[0004]

In the data transmission method using the chaining function, the data transfer sequence from the IC card to the terminal is defined by the RAM capacity of the IC card. For this reason, the terminal has a receiving capability (RA) that is longer than the data length transmitted at a time from the IC card.
M), it is necessary to transmit a continuous data request block every time data transmission from the IC card is completed, and the RAM capacity of the terminal is not satisfied. There was a problem that the capacity could not be fully utilized.

[0005] In the example shown in FIG.
Despite having a RAM capacity that can receive more than bytes of data, the data transmitted from the IC card
The data is transmitted after being divided into times. Each time the terminal is I
It is necessary to transmit a continuous data request block to the C card, which reduces the efficiency of data transfer from the IC card to the terminal.

An object of the present invention is to provide an IC card capable of transmitting long data at a time without being limited by the RAM capacity of the IC card.

[0007]

In order to achieve the above object, an IC card according to the present invention comprises a transmission buffer for storing a part of data to be transmitted to a terminal, and a transmission buffer for storing a length of the transmission buffer. A length storage unit, a maximum transmission block length storage unit that stores the length of one block that can be transmitted to the terminal at one time, and data not transmitted to the terminal among data transmitted in the one block. A transmission block remaining data length storage unit for storing the length of the data, and a remaining data length storage unit for storing the length of untransmitted data among all data transmitted to the terminal divided into a plurality of blocks. The configuration was made up of

With this configuration, while managing the length of the untransmitted data in one block, the data of the length of the transmission buffer is repeatedly transmitted until the maximum transmission block length of the terminal is reached, thereby obtaining the transmission buffer length. Can be transmitted in one block.

[0009]

Embodiments of the present invention will be described below with reference to the drawings. FIG.
It is a block diagram of a C card. The IC card 1 includes a nonvolatile memory 5 that is a memory unit for holding data, a transmission control unit 2 that controls transmission to and from a terminal (not shown), and controls data reading from the nonvolatile memory 5. A chaining control unit 3 is provided in addition to the data read processing unit 4. Further, the transmission control unit 2 has a transmission buffer 21 for temporarily storing transmission data.

[0010] The chaining control unit 3 has a storage unit for storing values of an IC card transmittable data length, a terminal receivable data length, and a transferred data length value.

Reference numeral 31 denotes a transmission buffer length storage unit,
The length of the transmission buffer 21 of the card 1 is written.
Until the maximum transmission block length is reached, data of the length of the transmission buffer is repeatedly transmitted.
The length of a block that the card 1 can transmit at one time depends on the reception buffer length of the terminal. Therefore, a maximum transmission block length storage unit in which the reception buffer length of the terminal is written is provided. 3
Reference numeral 2 denotes a maximum transmission block length storage unit in which the reception buffer length of the terminal is written. Reference numeral 33 denotes an entire remaining data length storage unit for managing the number of bytes of data that have not been read yet. Reference numeral 34 denotes a transmission block remaining data length storage unit for managing the number of bytes of data that has not yet been transmitted among data to be transmitted in one block.

[0012]

[Embodiment] As an embodiment of the present invention, a case where a command for instructing reading of 400 bytes of data is transmitted from a terminal to an IC card will be described.

First, prior to receiving a read command from a terminal, the IC card 1 writes a value of each data length into the transmission buffer length storage section and the maximum transmission block length storage section. As described above, the length of the transmission buffer 21 of the IC card 1 is written in the transmission buffer length storage unit 31, and this value is set to 100 bytes in this embodiment. In the maximum transmission block length storage unit, the reception buffer length of the terminal is written, and in this embodiment, this value is 250 bytes.

When the IC card 1 receives the read command sent from the terminal, the chaining control unit 3 writes the number of bytes of data that have not been read into the entire remaining data length storage unit 33. The entire remaining data length storage unit 33
Is written with the length of the data to be read. In this embodiment, a value of 400 bytes read from the IC card by the terminal is written as an initial value.

The chaining control unit 3 writes a value of 250 bytes, which is the maximum transmission block length, into the transmission block remaining data length storage unit 34 as an initial value. When the writing of the value to each storage section is completed, the control is transferred to the data read processing section 4.

Next, a data read sequence will be described. FIG. 2 shows a data read sequence in the present embodiment. When the storage of the values in the storage units described above is completed, the processing unit 4 subsequently reads the data stored in the nonvolatile memory 5.

The IC card continuously transmits the read data until the data reaches the maximum transmission block length. When the transmission of the first block is completed, the terminal transmits a continuous data request block to the IC card. . The IC card continues to save the already sent 250 bytes to 1
The transmission of the data of 400 bytes is completed by transmitting the data of 50 bytes.

Hereinafter, the data reading sequence will be described in detail. After the values are written into the respective storage units as described above, the processing unit 4 transmits the data of the first block.
The value (250 bytes) stored in the transmission block remaining data length storage unit 34 is larger than the value (100 bytes) stored in the transmission buffer length storage unit 31. For this reason,
The processing unit 4 reads 100 bytes of data corresponding to the transmission buffer length from the non-volatile memory 5,
1 is stored.

The transmission control unit 2 transmits the data stored in the transmission buffer 21 to the terminal. At this time, since 100 bytes of data have been transmitted to the terminal, the data read processing unit 4
Subtracts 100 bytes, which is the length of the data transmitted this time, from the current value (250 bytes) stored in the transmission block remaining data length storage unit 34, and newly adds a value of 150 bytes to the transmission block remaining data length. It is stored in the long storage unit 34.

Subsequently, the data read processing section 4 reads data stored in the nonvolatile memory. Since the value (150 bytes) stored in the transmission block remaining data length storage unit 34 is larger than the value (100 bytes) stored in the transmission buffer length storage unit 31, the next 100 bytes are stored in the same manner as described above. Is read from the nonvolatile memory 5 and stored in the transmission buffer 21. After the transmission control unit 2 transmits the data stored in the transmission buffer 21 to the terminal,
The data read processing unit 4 further subtracts the value of the currently transmitted data of 100 bytes from the current value of 150 bytes stored in the transmission block remaining data length storage unit 34 to obtain a value of 50 bytes. The value is newly stored in the transmission block remaining data length storage unit 34.

The value (50 bytes) stored in the transmission block remaining data length storage unit 34 is stored in the transmission buffer length storage unit 3.
Since the value is smaller than the value (100 bytes) stored in 1, the data read processing unit reads 50 bytes of data from the nonvolatile memory 5 and stores the data in the transmission buffer 21. After that, the transmission control unit 2 transmits the data stored in the transmission buffer 21 to the terminal.

Thus, the transmission of the first block (250 bytes) is completed, and the terminal transmits a continuous data request block to the IC card 1. When the IC card 1 receives the continuous data request block, the transmission of the second block is started.

The data reading processor 4 stores the current value (400 bytes) stored in the entire remaining data length storage 33.
Is subtracted from the value of 250 bytes, which is the length of the first block already transmitted, and a value of 150 bytes is newly stored in the entire remaining data length storage unit 33. Since the value of 150 bytes is smaller than the value (250 bytes) stored in the maximum transmission block length storage unit 32, this 1
The value of 50 bytes is the remaining transmission block data length storage unit 3
4 is written as a new initial value.

Next, as in the transmission of the first block, the data read processing unit 4 transmits the remaining data length of the transmission block storage unit 3.
4 is larger than the value (100 bytes) stored in the transmission buffer length storage unit 31, the next 100 bytes of data are read from the non-volatile memory 5, and the transmission buffer 21.

After the transmission control unit 2 transmits the data stored in the transmission buffer 21 to the terminal, the data read processing unit 4
Subtracts the value of 100 bytes which is the length of the data transmitted this time from the current value (150 bytes) stored in the transmission block remaining data length storage unit 34, and newly adds a value of 50 bytes to the transmission block. Remaining data length storage unit 34
To be stored.

Further, the data reading processor 4 stores the value (50) stored in the transmission block remaining data length storage 34.
Is smaller than the value (100 bytes) stored in the transmission buffer length storage 31, the next 50 bytes of data are read from the nonvolatile memory 5 and stored in the transmission buffer 21. After that, the transmission control unit 2 transmits the data stored in the transmission buffer 21 to the terminal. As a result, the transmission of the second block is completed, and at the same time, the transmission of all 400-byte data specified by the terminal is completed.

As is apparent from FIG.
The continuous data request block to be transmitted to the card is only once, so that efficient transmission can be performed. This effect becomes more remarkable as the data length to be read is longer.

[0028]

As described above, according to the present invention, the means for storing the length of the transmission buffer, the means for storing the maximum transmission block length, and the length of untransmitted data in one block are determined. By having a storage means,
Long data can be transmitted at one time without being limited by the capacity of the RAM of the C card.

[Brief description of the drawings]

FIG. 1 is a configuration diagram of an IC card of the present invention.

FIG. 2 is a diagram showing a data read sequence in the embodiment of the present invention.

FIG. 3 is a diagram showing a conventional data read sequence.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 IC card 2 Transmission control part 3 Chaining control part 4 Data read processing part 5 Nonvolatile memory 21 Transmission buffer 31 Transmission buffer length storage part 32 Maximum transmission block length storage part 33 Overall remaining data length storage part 34 Transmission block remaining data Long storage unit

Claims (1)

[Claims] 1. An IC card having a memory unit for storing data, dividing the data into a plurality of blocks, and transmitting the divided blocks to an external terminal, wherein a part of the data transmitted to the terminal is stored. A transmission buffer, a transmission buffer length storage unit that stores the length of the transmission buffer, a maximum transmission block length storage unit that stores the length of one block that can be transmitted to the terminal at one time, In the data sent in the block,
A transmission block remaining data length storage unit that stores a length of data that has not been transmitted to the terminal, and a length of untransmitted data among all data transmitted to the terminal divided into the plurality of blocks. And a remaining data length storage unit for storing the data length.