 |
Claims  |
|
|
What is claimed is:
1. A data transmission system for a portable data storage medium,
comprising:
a portable data storage medium having a data memory, and a control element
for reading out data from the data memory; and
an external device for sending a data readout command message to the
portable data storage medium, and receiving a response message from the
portable data storage medium,
means for transmitting data between the portable data storage medium and
said external device, said means including:
first means for transmitting a readout command message from the external
device to the portable data storage medium, and a status data item
representative of the result of processing started in response to the
readout command message and a data item read out from said data memory are
output from the portable data storage medium to the external device;
second means for second transmitting from said external device a continuous
data demand command to said portable data storage medium, when the
external device judges that there is additional data sent to the external
device after the first transmission step;
third means for outputting from the portable data storage medium, which has
received the continuous data demand command from the external device, a
data item remaining in the data memory to the external device;
fourth means for transmitting an abnormality response from the portable
data storage medium to the external device, when an abnormality occurs
during the processing in the portable data storage medium which has been
started in response to the readout command message; and
fifth means for transmitting, subsequent to the abnormality response output
when the abnormality occurred a status data item different from a status
data item output at the time of normal readout is output from the portable
data storage medium to the external device.
2. The system according to claim 1, wherein the portable data storage
medium comprises an IC card, and the external device comprises a card
reader/writer.
3. The system according to claim 1, wherein the abnormality response is a
delimiter message comprising a message start data and a message end data.
4. The system according to claim 1, wherein the second transmitting means
includes means for comparing a message length data item, which is included
in a response message output of the first transmitting means, with the
length of a memory data item, thereby to judge the presence of an
additional data.
5. A data transmission system for a portable data storage medium which
reads out data from a data memory in response to a readout command from an
external device and supplies the readout data to the external device, and
also which transmits additional data based on a continuous data demand
command fed from the external device, the system including:
means for outputting an abnormality response or a delimiter message from
the portable data storage medium to the external device, when an
abnormality occurs during the readout of the additional data, in response
to the continuous data demand command from the external device; and
means for outputting, subsequent to the outputting of the delimiter
message, an abnormal status data item from the portable data storage
medium to the external device.
6. A data transmission system for a portable data storage medium,
comprising:
a portable data storage medium having a data memory;
a temporary memory for temporarily storing data read out from the data
memory;
an external device for transmitting a command message to the portable data
storage medium and receiving a response message from the portable data
storage medium; and
a control section for controlling the readout of data from the data memory
and the transmission of data in the temporary memory to the external
device, and means for transmitting data between the portable data storage
medium and the external device, said including:
first means for transmitting in which data is read out from the data memory
in response to a readout command message supplied from the external
device, and a status data item representative of the result of the
readout, a data item representation of data length and a data item read
out from the data memory are transmitted to the external device via the
temporary memory;
second means for transmitting in which a continuous data demand command is
transmitted to the portable data storage medium, when the external device
judges that there is a continuous data item from the data sent to the
external device in the first transmitting and from the data item
representative data length;
third means for transmitting in which the portable data storage medium,
which has received the continuous data demand command from the external
device in the second means for transmitting, reads out a continuous data
item from the data memory and transmits the readout data to the external
device via the temporary memory;
fourth means for transmitting a data discontinuation message is output from
the portable data storage medium to the external device, when an
abnormality occurs during the readout from the data memory in the third
transmitting; and
fifth means for transmitting in which, subsequent to the data
discontinuation message output in the fourth transmitting, a status data
item different from a status data item output at the time of normal
readout is output from the portable data storage medium to the external
device.
7. The system according to claim 6, wherein the portable data storage
medium comprises an IC card, and the external device comprises a card
reader/writer.
8. The system according to claim 6, wherein the data discontinuation
message comprises a message start data item, a data item and a message end
data item, and the abnormality response is a delimiter message consisting
of a message start data and a message end data.
9. In a data transmission system for a portable data storage medium,
comprising a portable data storage medium having a data memory, and a
control element for reading out data from the data memory, and an external
device for sending a data readout command message to the portable data
storage medium, and receiving a response message from the portable
electronic device, a method for data transmitting between the portable
data storage medium and the external device is performed by a process
comprising the steps of:
a first transmission step in which a readout command message is supplied
external device to the portable data storage medium, and a status data
item representative of the result of processing started in response to the
readout command message and a data item read out from the data memory are
output from the portable data storage medium to the external device;
a second transmission step in which the external device transmits a
continuous data demand command to said portable data storage medium, when
the external device judges that there is a continuous data item from the
data sent to the external device in the first transmission step;
a third transmission step in which the portable data storage medium, which
has received the continuous data demand command from the external device
in the second transmission step, outputs a data item remaining in the data
memory to the external device;
a fourth transmission step in which an abnormality response is output from
the portable data storage medium to the external device, when an
abnormality occurs during the processing in the portable data storage
medium which has been started in response to the readout command message;
and
a fifth transmission step in which, subsequent to the abnormality response
output when the abnormality occurred in the fourth transmission step, a
status data item different from a status data item output at the time of
normal readout is output from the portable data storage medium to the
external device.
10. The method according to claim 9, wherein the abnormality response is a
delimiter message consisting of a message start data and a message end
data.
11. The method according to claim 9, wherein the second transmission step
includes a step of comparing a message length data item, which is included
in a response message output in the first transmission step, with the
length of a memory data item, thereby to judge the presence of a
continuous data item.
12. A method for data transmission for a portable data storage medium which
reads out data from a data memory in response to a readout command from an
external device and supplies the readout data to the external device, and
also which transmits continuous data based on a continuous data demand
command fed from the external device, comprising the steps of:
a first step in which an abnormality response or a delimiter message is
output from the portable data storage medium to the external device, when
an abnormality occurs during the readout of the continuous data, in
response to the continuous data demand command from the external device;
and
a second step in which, subsequent to the step of outputting the delimiter
message, an abnormal status data item is output from the portable data
storage medium to the external device.
13. In a data transmission for a portable data electronic device, including
a portable data storage medium having a data memory, a temporary memory
for temporarily storing data read out from the data memory, an external
device for transmitting a command message to the portable data storage
medium and receiving a response message from the portable data storage
medium; and
a control section for controlling the readout of data from the data memory
and the transmission of data in the temporary memory to the external
device, a method for data transmission between the portable data storage
medium and the external device comprising the steps of:
a first transmission step in which data is read out from the data memory in
response to a readout command message supplied from the external device,
and a status data item representative of the result of the readout, a data
item representation of data length and a data item read out from the data
memory are transmitted to the external device via the temporary memory;
a second transmission step in which a continuous data demand command is
transmitted to the portable data storage medium, when the external device
judges that there is a continuous data item from the data sent to the
external device in the first transmission step and from the data item
representative data length;
a third transmission step in which the portable data storage medium, which
has received the continuous data demand command from the external device
in the second transmission step, reads out a continuous data item from the
data memory and a transmits the readout data to the external device via
the temporary memory;
a fourth transmission step in which a data discontinuation message is
output from the portable data storage medium device to the external
device, when an abnormality occurs during the readout from the data memory
in the third step; and
a fifth transmission step in which, subsequent to the data discontinuation
message output in the fourth transmission step, a status data item
different from a status data item output at the time of normal readout is
output from the portable data storage medium to the external device.
14. The method according to claim 13, wherein the data discontinuation
message consists of a message start data item, a data item and a message
end data item, and the abnormality response is a delimiter message
consisting of a message start data and a message end data. |
|
 |
|
 |
Claims |
|
|
|
Description |
|
|
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to an improvement of a data transmission
arrangement (apparatus and method) for data transmission between a
portable electronic device such as an IC card and an external device.
2. Description of the Related Art
Recently, an IC card has been developed as a new type of portable data
storing medium. The IC card contains an IC chip having a non-volatile
memory section and a control section such as a CPU for controlling the
memory section. As shown in FIG. 1, a data memory 21 built in this type of
IC card has a plurality of areas having different storage capacities, and
each area contains a plurality of record data items. Depending on the
types of application software, the areas are divided, and the record data
items are divided as units of data.
The IC card receives a storage demand data item from a card reader/writer
serving as an external device. In this case, a data item to be stored is
handled as a unit of a record data item.
The record data item is called a "record format". The record format
consists of a length data item, which indicates the length of a storage
data item, and the storage data corresponding to the the length data item.
The IC card has a function for storing a record format as it is, and a
function for outputting the record format in response to a readout demand.
A record data item to be retrieved is recognized and selected from among
the record data items stored in a predetermined area of the data memory
21. On the other hand, the card reader/writer has the function for
recognizing the record data item output from the data memory 21.
The amount of a message to be processed in a single transmission operation
between the IC card and the card reader/writer is limited by the capacity
of a buffer memory (not shown), for the input/output of the IC card, and
by transmission regulations. Depending on the capacity and the contents of
the regulations, several transmission operations may be required for the
processing of one record.
For example, in an IC card using a text format protocol consisting of a
message start data (message start code), a data section and a message end
data (message check code), as shown in FIG. 2, when the IC card receives a
record readout command consisting of a data item 1 which is so large that
it cannot be transmitted in one transmission operation, then its length
data L1, the data item 1 is transmitted in the form of four response
message components.
As shown in FIGS. 3A to 3D, a first response message consisting of a
message start data item, a currently executed command (readout command), a
record readout status data item or an executed result (normal readout of a
target record data item), a length data item L1, a data section 1(1), and
a message end data item. Each of second to fourth response messages
consists of a message start data item, a data section 1(2), (1(3),or
1(4)), and a message end data item.
The status data item represents, as a response to the record data readout
command, the meaning "normal readout of a target data item", "a target
record data item is not present", or "message format does not correspond
to a record readout command".
The card reader/writer evaluates the length of the target record data item,
based on the length data L1 in the first response message from the IC
card, as shown in FIG. 3, and performs the processing corresponding to the
length of the target record data item.
Normally, when the IC card receives a readout command, it transmits the
first to fourth response messages. It is supposed that the data readout is
not smoothly performed and the transmission of data items is discontinued.
In this case, as shown in FIG. 4, the IC card outputs an error response
(or a record data item discontinuation response) to the card reader/writer
in response to a continuous data demand command from the card
reader/writer. Since the card reader/writer has received a status data
item indicating "normal readout", which is included in the first message,
the card reader/writer erroneously receives the record data item
discontinuation response as a continuous record data item.
In order to avoid the erroneous operation of the card reader/writer, when
data discontinuation occurs, the output of a sequence of output messages
is at once stopped. Next, a continuation end data item is super-imposed on
a message start data item of the last record data item which can be
readout. When the card reader/writer receives the continuation end data
item, it concludes that the output of data has stopped before all record
data items are readout. Also, as shown in FIG. 5, the card reader/writer
outputs a status data demand command to the IC card. Thus, the card
reader/writer is required to output the status data demand command, though
it could repeat the output of only continuous data demand commands if the
transmission of data were normally continued.
This being the case, the conventional system has the following problem.
Namely, where a plurality of messages corresponding to one command are
transmitted between a card reader/writer and an IC card, even if a status
data item, which is different from the status data item included in the
first message, is output from the IC card to the card reader/writer, the
card reader/writer cannot recognize it. If the card reader/writer is
forcibly made to recognize the status data item, the transmission of data
is discontinued.
SUMMARY OF THE INVENTION
The present invention solves the above problem associated with a
conventional system. This invention provides a data transmission system
for a portable electronic device wherein a plurality of messages
corresponding to one command are transmitted between an external device
and a portable electronic device (portable memory medium). According to
this invention, even if a status data item, which is different from the
status data item included in the first message, is output from the
portable electronic device to the external device, the external device can
recognize the status data item which is different from that in the first
message. In this case, the transmission of messages corresponding to one
command is not discontinued.
In order to achieve the above object, a data transmission system for a
portable electronic device, according to the present invention, comprises:
a portable electronic device having a data memory, and a control element
for reading out from the data memory; and
an external device for sending a data readout command message to the
portable electronic device, and receiving a response massage from the
portable electronic device.
Data is transmitted between the portable electronic device and the external
device is performed by the following steps;
a first transmission step in which a readout command message is supplied
from the external device to the portable electronic device, and a status
data item representative of the result of processing started in response
to the readout command message and a data item read out from the data
memory ar output from the portable electronic device to the external
device;
a second transmission step in which the external device transmits a
continuous data demand command to said portable electronic device, when
the external device judges that there is a continuous data item from the
data sent to the external device in the first transmission step;
a third transmission step in which the portable electronic device, which
has received the continuous data demand command from the external device
in the second transmission step, outputs a data item remaining in the data
memory to the external device;
a fourth transmission step in which an abnormality response is output from
the portable electronic device to the external device, when an abnormality
occurs during the processing in the portable electronic device which has
been started in response to the readout command message; and
a fifth transmission step in which, subsequent to the abnormality response
output when the abnormality occurred in the fourth transmission step, a
status data item different from a status data item output at the time of
normal readout is output from the portable electronic device to the
external device.
In the data transmission system for a portable electronic device, which has
the above structure, when a plurality of messages need to be transmitted
for one command between an external device and a portable electronic
device, even if a status data item, which is different from that included
the first message, is output from the portable electronic device to the
external device, the external device can recognize the status data item
different from that in the first message. In this case, the transmission
of data for one command is not discontinued.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 shows an example of a structure of a data memory included in an IC
card used in the present invention, and an example of a record format;
FIG. 2 shows an example of a message format used in the IC card and a card
reader/writer used in the present invention;
FIGS. 3A to 3D show examples of structures of response messages which are
transmitted sequentially in response to one command;
FIGS. 4 and 5 schematically show conventional transmission sequences of
commands and responses between a card reader/writer and an IC card;
FIG. 6A shows a structure of the IC card used in the present invention, and
the card reader/writer connected to the IC card;
FIG. 6B shows a structure of an IC card serving as the portable electronic
device according to the present invention and a structure of a terminal
device for handling the IC card;
FIG. 6C shows a block diagram illustrating the function of the portable
electronic device of the invention;
FIG. 6D shows an example of a structure of the IC card serving as the
portable electronic device of the invention;
FIG. 7 schematically shows a transmission sequence of commands and
responses, when the IC card functions normally;
FIG. 8 schematically shows a transmission sequence of commands and
responses, when the IC card malfunctions during processing in response to
the command from the card reader/writer in the system of the present
invention; and
FIG. 9 shows an example of a structure of a delimiter serving as a data
discontinuation response to be supplied from the IC card to the card
reader/writer, when the IC card malfunctions in the system of the present
invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
An embodiment of the data transmission system for a portable electronic
device, according to the present invention, will now be described with
reference to the accompanying drawings.
FIG. 6A is a block diagram showing a structure of a portable electronic
device used in the present invention, which comprises a card reader/writer
11 and an IC card (portable memory medium) 12. FIG. 6B shows a structure
of an IC card serving as the portable electronic device of the present
invention and a structure of a terminal device for handling the IC card.
An IC card 12 can be connected to a control section 3 such as a CPU
through a card reader/writer 11, and the control section 3 is connected to
a keyboard 4, a CRT display 5, a printer 6 and a floppy disc device 7. The
IC card 12 is owned by a user, and it stores key data (PIN) known only by
the user, which is collated in buying goods, and other necessary data.
FIG. 6C shows functional blocks of the IC card. The IC card comprises a
read/write section 11, a PIN setting/collating section 120 and an
encrypting/decrypting section section 13, which execute basic functions,
and a supervisor 14 for supervising these functions.
The read/write section 11 performs readout, write-in or erasure of data
with respect to a data memory 16.
The PIN setting/collating section 120 performs storing of a user's PIN and
readout prohibition processing. After the PIN has been set, the PIN
setting/collating section 120 collates the PIN, thus allowing subsequent
processing.
The encrypting/decrypting section 13 encrypts communication data for
preventing the data from being leaked or counterfeited when the data is
transmitted from the control section 3 to other terminal device, for
example, via a communication line. Also, the encrypting/decrypting section
13 decrypts the encrypted data. The encrypting/decrypting section 13
processes data based on a encrypting algorism having cryptogrammic
efficiency, such as DES (Data Encryption Standard).
The supervisor 14 decrypts a function code or a function code accompanied
with data, which is supplied from the card read/write 11 and performs a
necessary function.
In order to perform the above functions, the IC card 12 comprises, as shown
in FIG. 6D, a control element 15 such as a CPU, a data memory 16, a
program memory 17, and a contact portion 18 for electrical contact with
the card reader/writer 11. The control element 15, data memory 16, and
program memory 17 are integrated on a single IC chip (or a plurality of
chips) and embedded in the IC card body.
The program memory 17 is formed, for example, as a mask ROM, and stores a
control program of the control element 15 which is provided with
sub-routions for achieving the above basic functions.
The data memory 16 is used for storing various data items, and is composed,
for example, of an erasable non-volatile memory such as an EEPROM
(electrically erasable and programmable ROM).
The data transmission between the card reader/writer 11 and the IC card 12
is performed such that a plurality of messages are read out from the IC
card 12 in response to a specific record data readout command fed from the
card reader/writer 11.
In other words, the card reader/writer 11 outputs command messages to the
IC card 12 and receives response messages from the IC card 12.
The IC card 12 includes a data memory 21 and a control element (CPU) 22.
The message transmitted between the IC card 12 and the card reader/writer
11 has a structure as shown in FIGS. 3A to 3D. A detailed description
thereof may be omitted. However, it should be noted that a delimiter
message (described later) consists only of a message start code and a
message check code, and does not include a memory data, as shown in FIG.
9.
Transmission of messages between the IC card 12 and the card reader/writer
11 in the portable electronic device having the above structure will now
be described.
FIG. 7 shows a message transmission sequence in the normal condition. A
readout command message is transmitted from the card reader/writer 11 to
the IC card 12. In response to the readout command message, the IC card 12
outputs to the card reader/writer 11 a readout data response (first
response message) as shown in FIG. 3A, which consists of a memory data
item 1(1), which is a portion of a record data item designated by the
readout command message and dividedly stored in the data memory 21 (FIG.
1), a message length L1, a status data item (indicating the normal readout
of target record data), and a message start code added to the top of the
first response message, and a message check code added to the end of the
first response message.
The card reader/writer 11 compares the message length L1 and the length of
memory data 1(1) included in the first readout data response message, to
judge whether or not there is additional data. If there is additional
data, the card reader/writer 11 transmits a continuous data demand command
to the IC card 12. Responding to the continuous data demand command, the
IC card 12 outputs to the card reader/writer 11 a continuous data response
message (second response message) as shown in FIG. 3(B), which consists of
a memory data 1(2) (a second portion of the target record data), a message
start code, and a message check code.
Then, upon receiving the continuous data response message from the IC card
12, the card reader/writer 11 compares the message length L1 included in
the readout data response with the total length of the memory data 1(1)
and memory data 1(2), thereby to judge whether or not these is additional
data. If there is additional data, the card reader/writer 11 transmits a
continuous data demand command to the IC card 12. Responding to the
continuous data demand command, the IC card 12 outputs to the card
reader/writer 11 a continuous data response message (third response
message) as shown in FIG. 3(C), which consists of a memory data 1(3) (a
third portion of the target record data), a message start code, and a
message check code.
Upon receiving the continuous data response message from the IC card 12,
the card reader/writer 11 compares the message length L1 included in the
readout data response with the total length of the memory data 1(1),
memory data 1(2) and memory data 1(3), thereby to judge whether or not
additional data is needed. If there is additional data, the card
reader/writer 11 transmits a continuous data demand command to the IC card
12. Responding to the continuous data demand command, the IC card 12
outputs to the card reader/writer 11 a continuous data response message
(fourth response message) as shown in FIG. 3(D), which consists of a
memory data 1(4) (a fourth portion of the target record data), a message
start code, and a message check code.
Then, upon receiving the continuous data response message from the IC card
12, the card reader/writer 11 compares the message length L1 included in
the readout data response with the total length of the memory data 1(1),
memory data 1(2), memory data 1(3) and memory data 1(4), thereby to judge
whether or not additional data is needed. If there is no more additional
data, the card reader/writer 11 does not transmit a continuous data demand
command to the IC card 12 and the processing is completed.
Message transmission in the case where a transmission error or a data
discontinuation occurs in the IC card during the processing responding to
the readout command from the card reader/writer will now be described with
reference to FIG. 8. A readout command message is output from the card
reader/writer 11 to the IC card 12. Upon receiving the readout command
message, the IC card 12 outputs to the card reader/writer 11 a readout
data response (first message) as shown in FIG. 3A, which consists of a
memory data item 1(1), which is a portion of a record data item designated
by the readout command message and dividedly stored in the data memory 21
(FIG. 1), a message length L1 of the designated record data item, a status
data item (indicating the normal readout of target record data), and a
message start code added to the top of the first response message, and a
message check code added to the end of the first response message.
The card reader/writer 11 compares the message length L1 and the length of
memory data 1(1) included in the first readout data response message, to
judge whether or not there is additional data. If there is additional
data, the card reader/writer 11 transmits a continuous data demand command
to the IC card 12. Responding to the continuous data demand command, the
IC card 12 outputs to the card reader/writer 11 a continuous data response
message (second message) as shown in FIG. 3(B), which consists of a memory
data 1(2) (a second portion of the target record data), a message start
code, and a message check code.
Then, upon receiving the continuous data response message from the IC card
12, the card reader/writer 11 compares the message length L1 included in
the readout data response with the total length of the memory data 1(1)
and memory data 1(2), thereby to judge whether or not there is additional
data. If there is additional data, the card reader/writer 11 transmits a
continuous data demand command to the IC card 12.
Responding to the continuous data demand command, a memory data item
following the memory data item 1(2) is read out from the data memory 21 of
the IC card 12 in response to the target record data. In this case, if the
IC card 12 judges the occurrence of data discontinuation and fails to read
out the memory data item following the memory data item 1(2) before the
completion of the message length L1 of the designated record data, then
the IC card 12 outputs to the card reader/writer 11 a data discontinuation
response (or a delimiter message for separating the message including the
record data and the message including the status data) as shown in FIG. 9,
which consists of the message start code and the message check code and
does not include a memory data item. The message start code of the
delimiter message representing the data discontinuation response indicates
that the processing responding to the readout command is continuing.
The card reader/writer 11 judges the data discontinuation response fed from
the IC card to be the delimiter message, from the fact that the data
discontinuation response does not include a memory data item, and
recognizes the status data sent from the IC card 12 in response to the
next continuous data demand command from the card reader/writer 11. After
recognizing the end of the memory data and the continuation of
transmission, the card reader/writer 11 sends a continuation data demand
command once again to the IC card 12. Upon receiving the continuation data
demand command, the IC card 12 outputs to the card reader/writer 11 an
error response consisting of a status data representative of data
discontinuation, a message start code and a message check code. The
message start data in the error response indicates the end of message
transmission started in response to the readout command. Upon receiving
the error response from the IC card 12, the card reader/writer 11
completes the message transmission started by the output of the readout
command.
As described above, in the present invention, the delimiter message
separates the message including the record data and the message including
the status data. Thus, in the system wherein a plurality of messages are
transmitted in response to one command, even if a status data different
from the status data included in the first message is output, the card
reader/writer can recognize the status data different from that in the
first message. In this case, the data transmission started in response to
one command is not discontinued.
Suppose that the IC card 12 receives an "all record readout command" from
the IC card reader/writer 11, which demands readout of all data from the
data memory 21, and the contents of the data memory 21 consist of three
records, i.e., L1+data (1), L2+data (2) and L3+data (3), as shown in FIG.
1. At the time of readout of record "L1+data (1)", if all length data (1)
indicated by L1 cannot be read out, the IC card 12 supplies an abnormality
message or an error response to the IC card reader/writer 11, based on the
above process. In this case, the error response indicates continuation of
communication. Since the error response relating to the record
"L1+data(1)" has been sent from the IC card to the IC card reader/writer
11 in the data transmission continuation state, the IC card reader/writer
11 delivers a continuous data demand command to the IC card 12. Thus, the
IC card 12 can execute the readout of subsequent record "L2+data(2)". As
stated above, regarding the abnormality occurring in the readout of
records "L1+data(1)" and "L2+data(2)", the IC card supplies a status
signal in the form of delimiter message to the IC card reader/writer 11,
and the IC card delivers the error response to the card reader/writer in
the transmission continuous state. Thus, while the IC card reader/writer
11 is being informed of the readout abnormality, the IC card 12 can read
out the rest of the data, without interrupting the data transmission.
* * * * *
|
|
|
|
|
|
|
Description |
|
