Registers – Records – Conductive
Reexamination Certificate
2002-05-20
2003-08-19
Pitts, Harold I. (Department: 2876)
Registers
Records
Conductive
C235S487000
Reexamination Certificate
active
06607138
ABSTRACT:
This application claims foreign priority under 35 U.S.C. §119 to JP 2001-153145 filed May 22, 2001.
FIELD OF THE INVENTION
The present invention relates to a communication method of an IC card reader/writer and, more specifically, to a communication method of an IC card reader/writer which transmits a telegraphic message from a host device to an IC card or a telegraphic message from an IC card to a host device.
2. Background of the Invention
A host device such as a host computer normally uses an IC card reader/writer for communicating with contact-type IC cards.
FIG. 5
shows a sequence of a traditional communication of an IC card reader/writer that stands between a host device and an IC card for data communication.
The IC card reader/writer receives from the host device the entire telegraphic message that needs to be transmitted to the IC card (see code
101
) and temporarily stores it in the RAM (Random Access Memory) therein. Then, the IC card reader/writer converts the telegraphic message stored in the RAM in a telegraphic format by which the message can be communicated with the IC card. This telegraphic format is specified by the International Standard or the Domestic Standard. For example, the T=0 protocol and the T=1 protocol specified by the International Standard are well known.
In the communication between the IC card reader/writer and the IC card, a one-time transmissible data length is predetermined. Therefore, when the data length the IC card reader/writer has received from the host device is longer than the predetermined length, the data communication between the IC card reader/writer and the IC card is divided into multiple transmissions (Code
102
). Note that Laid-open Patent Application H1-213774 has disclosed the technology used for dividing the data, which the IC card reader/writer has received from the host device, to transmit the data of a predetermined length to the IC card.
The IC card reader/writer transmits all the data from the host device to the IC card, and then receives a response from the IC card (for example, a response information indicating a successful writing of the data on the IC card). Even for the transmission of the response information, if the length of the response information is longer than a predetermined length, the data communication between the IC card reader/writer and the IC card is divided into multiple transmissions (Code
103
).
Then, the IC card reader/writer saves all the response data from the IC card in the RAM. After the communication with the IC card is completed, the IC card reader/writer sends the response data, which it has received from the IC card, to the host device collectively (Code
104
).
In recent years, the memory capacity of IC cards and the communication capacity have been made larger. This has made the maximum length of the telegraphic message of IC card larger. Initially, the maximum length of the IC card telegraphic message was 261 bytes; however, the communication by 4K (4096) bytes and 8K (8192) bytes is now possible. In the future, a much larger communication capacity is expected to be made possible.
The conventional communication method of an IC card reader/writer described above does, however, have significant drawbacks. In particular, the conventional communication method requires the card reader/writer to equip more RAM that can manage the communication with IC cards having larger memory capacities. However, it may be impossible to upgrade the RAM capacity to 4K bytes, 8K bytes or more, depending on the CPU capacity. In such a case, the CPU needs to be replaced with an upgraded one. Even if the additional RAM may be installed, it can be costly. Also, even the CPU upgrade and additional RAM may not be sufficient for the IC card reader/writer to process the future IC cards which would have more communication capacities.
In view of the foregoing, there currently exists a need for a communication method of an IC card reader/writer which is capable of processing IC cards having larger communication capacities without requiring the CPU upgrade or the additional RAM.
SUMMARY OF THE INVENTION
It is accordingly an object of the present invention is to provide a communication method of an IC card reader/writer which is capable of processing IC cards having larger communication capacities without requiring the CPU upgrade or the additional RAM.
To achieve the above, the present invention is a communication method of an IC card reader/writer which transmits a telegraphic message from a host device to an IC card or from the IC card to the host device, wherein the host device divides the data into blocks, each of which is of a size smaller than the capacity of a memory device equipped in the IC card reader/writer, to transmit the data to IC card reader/writer, and attaches a code to each of the data blocks to indicate whether or not the block is the final data block.
Therefore, the IC card reader/writer receives from the host device the data blocks of a capacity that does not exceed the size of the memory device equipped therein, stores them in the memory device, and performs a predetermined process. In other words, the IC card reader/writer receives from the host device the data blocks, each of which is of a communication capacity storable in the memory device. Consequently the memory size of the IC card reader/writer does not affect the maximum communication capacity. Also, a code is attached to each of the data blocks to indicate whether or not the data block is the final data block. Thus, the IC card reader/writer is capable of determining whether or not there is a successive data block.
The invention may also be a communication method of an IC card reader/writer, wherein the IC card reader/writer stores the data blocks from the host device in the memory device to process, confirms that there is a successive data block and prompts the host device to send the successive data block; and then the host device sends the successive data block to the IC card reader/writer, responding to the prompt.
Therefore, the communication between the IC card reader/writer and the host device is performed within the communication capacity storable in the memory device equipped in the IC card reader/writer.
Thus, the memory size of the IC card reader/writer would not affect the maximum communication capacity.
The invention may also be a communication method of an IC card reader/writer, which transmits a telegraphic message from a host device to an IC card or from the IC card to the host device, the IC card reader/writer stores the data blocks from the IC card up to the capacity that does not exceed the size of a memory device equipped in the IC card reader/writer and sends the stored-up data to the host device collectively, and also attaches a code to the collective data, which is to be transmitted to the host device, to indicate whether or not it is the final data.
Therefore, the communication between the IC card reader/writer and the host device is performed within the communication capacity storable in the memory device equipped in the IC card reader/writer. Thus, the memory size of the IC card reader/writer does not affect the maximum communication capacity. Further, a code is attached to each of the collective data to indicate whether or not it is the final collective data. Thus, the host device can determine whether or not there is the successive data.
In accordance with one embodiment of the invention, a communication method of the IC card reader/writer is disclosed wherein, the host device divides the data into blocks of a size smaller than the capacity of a memory device equipped in the IC card reader/writer to transmit the data to the IC card reader/writer, and attaches a code to each of the data blocks to indicate whether or not the block is the final data block. Therefore, the memory size of the IC card reader/writer does not affect the maximum capacity of a series of data communications between the IC card and the host device. Consequently there is no need of upgrading the hardware such as the CPU
Pitts Harold I.
Reed Smith LLP
Sankyo Seiki Mfg. Co. Ltd.
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