JP2689740B2 - IC card - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an IC card capable of communicating with a plurality of independent data devices (external terminals) constituting a network, and more specifically, to quickly recover from a transmission error in this network. IC that can
About the card.

[0002]

2. Description of the Related Art A conventional IC card having a communication function is
Data communication is performed by a predetermined communication message (information block) with a terminal connected to this IC card in a one-to-one relationship. This communication message includes Japanese Patent Laid-Open No. 1-2
As disclosed in Japanese Patent No. 80889, in addition to the main sentence, an identifier for identifying the communication partner is included.

In this communication system, when an error due to line noise or the like, for example, a character error due to vertical parity or the like, a block error, or an error that makes the transmission partner unknown, occurs, the identifier in the communication telegram. In order to avoid the risk of overlooking transmission errors due to unreliability of all, the communication partner is all "unknown". Therefore, if you receive a telegram containing any of these errors, or if the communication partner is unknown, the terminal identified by the above identifier, or the terminal that was connected when the communication started The IC card will transmit a response message.

That is, conventionally, an IC card has a terminal and a terminal.
Data communication is being carried out in a one-to-one correspondence, and the other party (terminal) of the response was specified, so the above "Unknown party"
Even if such an error occurs, there was no problem that the response became unresponsive.

However, when a plurality of terminals DTE are connected on a single communication line (when a network is formed by one communication line), the IC card constituting one of the terminals has an error. Message (Error message that makes the communication partner unknown due to destruction of the above identifier)
When the message is received, the IC card cannot determine which terminal it should respond to, so that the IC card becomes a non-responsive state.

Therefore, in such a network, each terminal side sets its own waiting time for receiving a message from the IC card, and when the waiting time has passed, the next communication process is started. Yes (time-out processing).

[0007]

However, in such a conventional IC card, since the next communication processing is executed by the above-mentioned timeout processing when an error of unknown communication partner occurs, waiting time is wasted in each terminal. There was a problem that is occurring. In addition, there is a problem that the time monitoring at each terminal increases the burden on each terminal.

[0008] Therefore, an object of the present invention is to provide an IC card in which, when a transmission error that makes the communication partner unknown occurs, no time is wasted in recovering the communication function and the burden on each terminal is reduced. Is to provide.

[0009]

As shown in FIG. 1, the present invention is an IC card 100 capable of mutually performing data communication with a plurality of terminals DTE1 to DTEn via a reader / writer and a communication line. Receiving means 11 for receiving an information block including an identifier for identifying a transmitting terminal, an identifier for identifying a receiving terminal, and information for detecting a transmission error.
0 and error detection means 120 for detecting an unknown transmission error by the transmission terminal based on this transmission error detection information.
When the error detecting means 120 detects this transmission error, all the terminals D other than the self terminal are identified by the identifier.
Error notification specifying TE1 to DTEn as receiving terminals
The block is a smart card that includes a transmission unit 130 that transmits an error notification block that can start another communication process.

[0010]

In the IC card according to the present invention, the error detecting means 120 detects the transmission error based on the information block received by the receiving means 110. For example, the transmission error is detected by the error detection information (LRC, CRC, etc.) in the information block. When this transmission error is detected, the transmission unit 130 transmits an error notification block in which all the terminals DTE1 to DTEn other than itself are specified as the reception terminals.

Specifically, the CPU of the IC card creates an error notification block and sends this error notification block to the reader / writer. The reader / writer uses this error notification block for all terminals DTE networked by communication lines.
1 to DTEn.

Terminal D receiving this error notification block
The TEm (the terminal that has transmitted the information block to the IC card) can perform other communication processing immediately after receiving the error notification block instead of the time-out processing.
Also, this communication line can be used by other terminals.

[0013]

Embodiments of the IC card according to the present invention will be described below with reference to the drawings. 2 to 9 show an embodiment of the present invention.

As shown in FIG. 2, the IC card 11 is connected to a communication line L via a reader / writer 12, and data communication is individually performed with a plurality of terminals DTE1 to DTEn via the communication line L. Is possible.

The IC card 11 has a known structure and has a CPU, a RAM, a ROM and an I / O. That is, the IC card 11 uses the terminal DTE
1 to DTEn through the communication line L, it has a function capable of performing data communication. The IC card 11 has a configuration capable of receiving a communication message from a certain terminal DTE via the communication line L and transmitting a response to the terminal DTE by a predetermined communication message.

That is, the IC card 11 is used in a network composed of a plurality of communication terminals DTE1 to DTEn. Examples of this communication terminal DTE include a host computer and other communication devices.

The IC card 11 includes a receiving means, a transmitting means, and an interface, a CPU and the like.
It has error detection means.

The receiving means includes an identifier for identifying the transmitting terminal among the plurality of terminals DTE, an identifier for identifying the receiving terminal, and transmission error detection information (vertical parity, L).
RC, CRC, etc.) is received. FIG. 3 shows the format of this information block. As shown in this figure, in the item of the type in the information block, if the message content is a request, it is $ 00, if it is a response, it is $ 01, if it is an error notification, it is $ 02,
Each is shown. FIG. 4 shows the character frame structure in the information block received by the I / O.

Therefore, transmission / reception of data in this network can be performed in units of this information block. Further, a certain terminal DTE that has transmitted an information block (request) using this communication line L waits for reception of an information block (response) from the communication line L during the waiting time TW peculiar to that terminal. The terminal DTE is monitoring the communication line L during this time TW. Note that during this time TW, other terminals DTE cannot send requests.

Further, the error detecting means may generate a transmission error (the communication partner becomes unknown) based on the transmission error detection information included in the information block which is the request, or due to line noise or the like when the information block is received. Error).

Further, when the error detecting means detects a transmission error that the communication partner terminal is unknown, the transmitting means determines that the communication partner is unknown and determines all communication terminals DTE1 to DTEn existing in the network other than itself. As a receiving terminal, the error notification block identified by the above identifier is transmitted (transmitted via the reader / writer 12). FIG.
Shows this error notification block. That is, in this error notification block, $ 00 that specifies all terminals is specified as the communication identifier.

Therefore, from a terminal DTE (for example, a host computer) connected to this communication line L,
When the IC card 11 receives a specific telegram (a telegram for which the communication partner is unknown), the IC card 11 uses all the terminals DTE1 whose communication partners are connected to the communication line L.
A message (error notification block) including an identifier of ˜DTEn is created and transmitted to the reader / writer 12. The reader / writer 12 is placed on the communication line L to connect all terminals DTE1 to DTE.
This error notification block is transmitted to n.

As described above, the sharing of the communication line L of the network is performed according to the following rules. That is, the terminal (node) having the block to be transmitted monitors the line during the waiting time TW,
Blocks can be placed on the line and output only when the line is free. Further, while an arbitrary terminal sends out a request and waits for a response to this request (including a response to a communication error), another terminal cannot issue the request. The terminal that sent this request waits for a response. Furthermore, it is assumed that the terminal (IC card) that has detected the communication error sends an error notification block (FIG. 5) to all the other terminals.

The operation will be described below with reference to the flow charts shown in FIGS.

FIG. 6 shows a routine for receiving an information block in the IC card.

First, for the IC card, CPU initialization processing,
That is, the buffer pointer BUF, the error detection code register EDC, and the error register ERR are set to 0 (step S601).

Next, the character is input according to the procedure shown in FIG. 7 (S602).

Then, it is checked whether or not the error register ERX is 0 (S603). This error register ER
X is for the parity check of the information block.

If this error register ERX is 1, then
Since a parity error has occurred, 1 is assigned to the error register ERR (S604).

When the parity error check is completed, the contents of CHR (reception character register) (reception character data) are substituted into [BUF] and the buffer pointer BUF is incremented by 1 (S6).
05). The data is set.

Further, EDC, CH are added to the register EDC.
The exclusive OR of R is taken and the value is substituted (S606). The register EDC is updated.

The received character data is EOT.
It is checked whether or not (End of Text) (S60
7). If it is not EOT, the process returns to the next character input (return to S602).

If the character is EOT, it is checked whether the value obtained by subtracting the data held in the EDC from the data in the character register CHR is 0 (CHR-EDC = 0) (S608).

If this value is not 0, the error register E
2 is substituted into RR (S609).

Then, it is checked whether this register ERR is 0 (S610). This is LRC (horizontal parity)
Is to check.

If ERR is not 0, an error notification message is output (S611) and initialization processing step S6.
Returning to 01, on the other hand, if the ERR is 0, it is checked whether it is a message addressed to another person or a message addressed to himself (S612). If it is a message addressed to oneself, this program is terminated, and if it is a message addressed to another person, the process returns to the initialization step S601.

Next, the character receiving routine will be described with reference to FIG.

First, the state of the external terminal is input to the carry flag Cy by I / O (S701).

Next, it is checked whether this flag Cy is 0 (S702). As shown in FIG. 4, when the flag Cy becomes 0, it is determined that the bit is a start bit, the process proceeds to the next initialization step S703, 9 is substituted into the bit counter CNT, and 0 is substituted into the parity register PRT and the error register ERX.

Then, the device waits for 0.5 bit width (S704) and sets the I / O value to carry flag Cy.
(S705). Next, the parity register PR
The value of the carry flag Cy (the value of the data bit b1 in FIG. 4) is added to T (S706).

Then, the contents of the carry flag Cy are rotated by 1 bit in the character register CHR by the shift instruction (S707). Then, the counter CNT is decremented by 1 (S708). Furthermore, the counter C
It is checked whether the value of NT is 0 (S709), and if it is not 0, wait for 0.5 bit width (S7).
10) Return to step 704 and input the next bit value from the I / O.

By repeating S704 to S709 in this way, 9-bit character data is read.

When the counter CNT becomes 0, the value of the parity register PRT is divided by 2 and the remainder is 1.
It is checked whether it is 0 or not (S711), and if it is 1, 1 is assigned to the error register ERX. If it is 0, it is not a parity error, so the process returns to the main routine (S6 above)
01).

FIG. 8 shows an information block output routine.

First, it is checked whether another node (terminal) is waiting for a response (S801). If it is not waiting for a response, a timer is initialized (S802). Then, 1-bit data is substituted into the carry flag Cy from the I / O (S803), and it is checked whether or not the carry flag Cy is 1 (S804).

If the carry flag Cy is 1, the timer checks whether the waiting time TW has been exceeded (S80).
5) If it does not exceed, the process returns to step S803 for inputting from the external terminal. If the waiting time has elapsed, a predetermined information block (for example, an error notification block) is output (S806).

If the carry flag Cy is 0, the block reception routine is executed for another terminal (S8).
11) If the output block is not the error notification block, or if the received block is not the error notification block,
This terminal returns to the timer initialization step S602. In all other cases, this program ends.

FIG. 9 shows the output of the error notification block. $ 00 is set in the item of communication identifier shown in FIG. 5 (S902), and $ 02 is set in the item of type (S90
3) and block output (S903).

When the IC card 11 transmits the error notification block including the specified identifiers to which the communication partners are all terminals, each terminal side receiving this message immediately transmits the next message. Communication processing can be performed.

[0050]

[Effect] As described above, according to the present invention, an electronic message including an identifier that identifies all terminals other than the self IC
By transmitting from the card via the reader / writer ,
The other terminal side can immediately perform the next communication process, and waste of time can be omitted. Further, since the terminal does not need to monitor the waiting time for a message, the load on the terminal can be reduced.

[Brief description of the drawings]

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

FIG. 2 is a block diagram illustrating a network according to an exemplary embodiment of the present invention.

FIG. 3 is a block diagram showing a format of an information block of an IC card and a DTE according to an embodiment of the present invention.

FIG. 4 is a block diagram showing a character frame in an information block according to an embodiment of the present invention.

FIG. 5 is a block diagram showing a format of an error notification block according to an embodiment of the present invention.

FIG. 6 is a flowchart showing an information block receiving routine in the IC card according to the embodiment of the present invention.

FIG. 7 is a flowchart showing a subroutine of character reception by the IC card according to the embodiment of the present invention.

FIG. 8 is a flowchart showing an output routine of an information block of an IC card according to an embodiment of the present invention.

FIG. 9 is a flowchart showing an IC card error notification information output routine according to an embodiment of the present invention.

[Explanation of symbols]

 100 IC card 110 Receiving means 120 Error detecting means 130 Sending means DTE communication terminal

Claims (1)

(57) [Claims] 1. An IC card capable of mutually performing data communication with a plurality of terminals via a reader / writer and a communication line, the identifier specifying a transmitting terminal, the identifier specifying a receiving terminal, and transmission. Receiving means for receiving an information block containing information for error detection, error detecting means for detecting an unknown transmission error by the transmitting terminal based on this transmission error detecting information, and this error detecting means for detecting this transmission error. When detected,
A error notification block identified above all terminals other than the self as a receiving terminal by said identifier, the terminal which has received the error notification block transmitting means for transmitting the error notification block capable of initiating another communication process An IC card characterized by including.