U.S. patent application number 09/228412 was filed with the patent office on 2001-11-15 for method and system for controlling contactless ic cards.
Invention is credited to ANDO, KIMIAKI, DATE, SHIGERU, DOBASHI, HISANOBU, HIRATA, TATSUYA, MIURA, TORU, NISHIMURA, SHINJU, SATO, HIROMI, SATO, TADASHI, TAKAHASHI, KIYOSHI, TAKIGUCHI, MASAHIRO.
Application Number | 20010040185 09/228412 |
Document ID | / |
Family ID | 11578830 |
Filed Date | 2001-11-15 |
United States Patent
Application |
20010040185 |
Kind Code |
A1 |
TAKIGUCHI, MASAHIRO ; et
al. |
November 15, 2001 |
METHOD AND SYSTEM FOR CONTROLLING CONTACTLESS IC CARDS
Abstract
A reader/writer (RW) requires identification information pieces
of respective plural IC cards (A, B, C). The plural IC cards return
the respective identification information pieces in response to the
requirement by the reader/writer. Logical addresses are assigned to
some IC cards among the plural IC cards respectively to cause the
reader/writer to select them in response to the return of the
identification information pieces by the plural IC cards. The IC
cards selected by the reader/writer are controlled. The
reader/writer cancels the assignment of the logical address to one
of the selected IC cards. The logical address, the assignment of
which has been canceled by the reader/writer, is assigned to an IC
card among the plural IC cards to which any logical address has not
been assigned yet. The IC card to which the logical address has
just been assigned is controlled.
Inventors: |
TAKIGUCHI, MASAHIRO;
(ANJO-SHI, JP) ; TAKAHASHI, KIYOSHI;
(HENKINAN-SHI, JP) ; HIRATA, TATSUYA; (ANJO-SHI,
JP) ; DATE, SHIGERU; (TOKYO, JP) ; DOBASHI,
HISANOBU; (TOKYO, JP) ; NISHIMURA, SHINJU;
(TOKYO, JP) ; ANDO, KIMIAKI; (TOKYO, JP) ;
SATO, TADASHI; (HADANO-SHI, JP) ; SATO, HIROMI;
(SHIROISHI-SHI, JP) ; MIURA, TORU; (TOKYO,
JP) |
Correspondence
Address: |
PILLSBURY MADISON & SUTRO
INTELLECTUAL PROPERTY GROUP
NINTH FLOOR, EAST TOWER
1100 NEW YORK AVENUE NW
WASHINGTON
DC
200053918
|
Family ID: |
11578830 |
Appl. No.: |
09/228412 |
Filed: |
January 12, 1999 |
Current U.S.
Class: |
235/451 |
Current CPC
Class: |
G06K 7/10059 20130101;
G06K 7/0008 20130101 |
Class at
Publication: |
235/451 |
International
Class: |
G06K 007/08 |
Foreign Application Data
Date |
Code |
Application Number |
Jan 12, 1998 |
JP |
10-4232 |
Claims
What is claimed is:
1. A contactless IC card control system comprising: first means
(200) for causing a reader/writer (RW) to require identification
information pieces of respective plural IC cards (A, B, C); second
means (310) for causing the plural IC cards to return the
respective identification information pieces in response to the
requirement by the first means; third means (212, 213, 220, 230,
320) for assigning logical addresses to some IC cards among the
plural IC cards respectively to cause the reader/writer to select
the some IC cards among the plural IC cards in response to the
return of the identification information pieces by the second
means; fourth means (240, 241, 250, 340, 370) for controlling the
some IC cards selected by the reader/writer; fifth means (260, 261,
360) for causing the reader/writer to cancel the assignment of the
logical address to one of the some IC cards; sixth means (262, 263,
320, 330) for assigning the logical address, the assignment of
which has been canceled by the fifth means, to an IC card among the
plural IC cards to which any logical address has not been assigned
yet; and seventh means (264, 340, 370) for controlling the IC card
to which the logical address has been assigned by the sixth
means.
2. A method of controlling contactless IC cards, comprising the
steps of: causing a reader/writer (RW) to require identification
information pieces of respective plural IC cards (A, B, C); causing
the plural IC cards to return the respective identification
information pieces in response to the requirement by the
reader/writer; assigning logical addresses to some IC cards among
the plural IC cards respectively to cause the reader/writer to
select the some IC cards among the plural IC cards in response to
the return of the identification information pieces by the plural
IC cards; controlling the some IC cards selected by the
reader/writer; causing the reader/writer to cancel the assignment
of the logical address to one of the some IC cards; assigning the
logical address, the assignment of which has been canceled by the
reader/writer, to an IC card among the plural IC cards to which any
logical address has not been assigned yet; and controlling the IC
card to which the logical address has been assigned by the
immediately-preceding step.
3. A contactless IC card control system comprising: first means for
assigning a first logical address to a first IC card; second means
for assigning a second logical address to a second IC card, the
second logical address differing from the first logical address,
the second IC card differing from the first IC card; third means
for canceling the assignment of the first logical address to the
first IC card while maintaining the assignment of the second
logical address to the second IC card; and fourth means for, after
the assignment of the first logical address to the first IC card is
canceled by the third means, assigning the first logical address to
a third IC card which differs from the first and second IC
cards.
4. A contactless IC card control system comprising: first means for
assigning a first logical address to a first IC card; second means
for assigning a second logical address to a second IC card, the
second logical address differing from the first logical address,
the second IC card differing from the first IC card; third means
for controlling the first IC card in response to the first logical
address; fourth means for, after the third means controls the first
IC card, canceling the assignment of the first logical address to
the first IC card while maintaining the assignment of the second
logical address to the second IC card; and fifth means for, after
the assignment of the first logical address to the first IC card is
canceled by the fourth means, assigning the first logical address
to a third IC card which differs from the first and second IC
cards.
5. A contactless IC card control system as recited in claim 4,
further comprising sixth means for, after the fifth means assigns
the first logical address to the third IC card, controlling the
third IC card in response to the first logical address.
6. A contactless IC card control system as recited in claim 4,
further comprising sixth means for controlling the second IC card
in response to the second logical address.
Description
BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] This invention relates to a system for controlling
contactless IC (integrated circuit) cards. This invention also
relates to a method of controlling contactless IC cards.
[0003] 2. Description of the Related Art
[0004] In a prior-art contact IC card control system, IC cards
communicate with readers/writers when being inserted thereinto. In
each of the readers/writers, the type of an IC card placed
thereinto is detected as follows. When the IC card is reset, for
example, when the IC card is subjected to a power-on resetting
process, the IC card transmits a reset notice to a reader/writer.
The reset notice contains information of the type of the IC card.
The reader/writer identifies or detects the type of the IC card in
response to the reset notice transmitted from the IC card. Then,
the reader/writer implements the following processes related to the
identified IC card. First, the reader/writer assigns a logical
address to the IC card in accordance with the identified type
thereof. Second, the reader/writer controls the reading and the
writing of information from and into the IC card in response to the
logical address. The assignment of the logical address to the IC
card is canceled when the IC card is reset by turning off the power
supply.
[0005] In a contactless IC card control system, a reader/writer has
a communication service area (a communication coverage). The
reader/writer can communicate with an IC card or IC cards in the
communication service area by radio.
[0006] In a conceivable contactless IC card control system, a
reader/writer assigns different logical addresses to respective IC
cards in its communication service area. The reader/writer feeds
power to the IC cards by radio. When the power supply of the
reader/writer is turned off, power feed to all the IC cards is
suspended so that the assignment of the logical addresses thereto
is canceled at once. Accordingly, in the conceivable contactless IC
card control system, it is difficult to cancel the assignment of
the logical address to one of the IC cards. In addition, it is
difficult to control IC cards, the number of which exceeds the
number of usable logical addresses.
[0007] Generally, as the number of different logical addresses
increases, the number of bits representing each logical address
increases. An increase in the number of address-representing bits
is disadvantageous to signal processing which includes address
processing.
SUMMARY OF THE INVENTION
[0008] It is a first object of this invention to provide a system
for controlling contactless IC (integrated circuit) cards which can
cancel the assignment of a logical address to one of the IC
cards.
[0009] It is a second object of this invention to provide a method
of controlling contactless IC (integrated circuit) cards which can
cancel the assignment of a logical address to one of the IC
cards.
[0010] It is a third object of this invention to provide a system
for controlling contactless IC (integrated circuit) cards, the
number of which exceeds the number of usable logical addresses.
[0011] It is a fourth object of this invention to provide a method
of controlling contactless IC (integrated circuit) cards, the
number of which exceeds the number of usable logical addresses.
[0012] A first aspect of this invention provides a contactless IC
card control system comprising first means (200) for causing a
reader/writer (RW) to require identification information pieces of
respective plural IC cards (A, B, C); second means (310) for
causing the plural IC cards to return the respective identification
information pieces in response to the requirement by the first
means; third means (212, 213, 220, 230, 320) for assigning logical
addresses to some IC cards among the plural IC cards respectively
to cause the reader/writer to select the some IC cards among the
plural IC cards in response to the return of the identification
information pieces by the second means; fourth means (240, 241,
250, 340, 370) for controlling the some IC cards selected by the
reader/writer; fifth means (260, 261, 360) for causing the
reader/writer to cancel the assignment of the logical address to
one of the some IC cards; sixth means (262, 263, 320, 330) for
assigning the logical address, the assignment of which has been
canceled by the fifth means, to an IC card among the plural IC
cards to which any logical address has not been assigned yet; and
seventh means (264, 340, 370) for controlling the IC card to which
the logical address has been assigned by the sixth means.
[0013] A second aspect of this invention provides a method of
controlling contactless IC cards which comprises the steps of
causing a reader/writer (RW) to require identification information
pieces of respective plural IC cards (A, B, C); causing the plural
IC cards to return the respective identification information pieces
in response to the requirement by the reader/writer; assigning
logical addresses to some IC cards among the plural IC cards
respectively to cause the reader/writer to select the some IC cards
among the plural IC cards in response to the return of the
identification information pieces by the plural IC cards;
controlling the some IC cards selected by the reader/writer;
causing the reader/writer to cancel the assignment of the logical
address to one of the some IC cards; assigning the logical address,
the assignment of which has been canceled by the reader/writer, to
an IC card among the plural IC cards to which any logical address
has not been assigned yet; and controlling the IC card to which the
logical address has been assigned by the immediately-preceding
step.
[0014] A third aspect of this invention provides a contactless IC
card control system comprising first means for assigning a first
logical address to a first IC card; second means for assigning a
second logical address to a second IC card, the second logical
address differing from the first logical address, the second IC
card differing from the first IC card; third means for canceling
the assignment of the first logical address to the first IC card
while maintaining the assignment of the second logical address to
the second IC card; and fourth means for, after the assignment of
the first logical address to the first IC card is canceled by the
third means, assigning the first logical address to a third IC card
which differs from the first and second IC cards.
[0015] A fourth aspect of this invention provides a contactless IC
card control system comprising first means for assigning a first
logical address to a first IC card; second means for assigning a
second logical address to a second IC card, the second logical
address differing from the first logical address, the second IC
card differing from the first IC card; third means for controlling
the first IC card in response to the first logical address; fourth
means for, after the third means controls the first IC card,
canceling the assignment of the first logical address to the first
IC card while maintaining the assignment of the second logical
address to the second IC card; and fifth means for, after the
assignment of the first logical address to the first IC card is
canceled by the fourth means, assigning the first logical address
to a third IC card which differs from the first and second IC
cards.
[0016] A fifth aspect of this invention is based on the fourth
aspect thereof, and provides a contactless IC card control system
further comprising sixth means for, after the fifth means assigns
the first logical address to the third IC card, controlling the
third IC card in response to the first logical address.
[0017] A sixth aspect of this invention is based on the fourth
aspect thereof, and provides a contactless IC card control system
further comprising sixth means for controlling the second IC card
in response to the second logical address.
BRIEF DESCRIPTION OF THE DRAWINGS
[0018] FIG. 1 is a diagram of a contactless IC card control system
according to an embodiment of this invention.
[0019] FIG. 2 is a block diagram of an electrical portion of a
reader/writer in FIG. 1.
[0020] FIG. 3 is a block diagram of an electrical portion of an IC
card in FIG. 1.
[0021] FIGS. 4 and 5 are a flowchart of a program for a
microcomputer in the reader/writer of FIG. 2.
[0022] FIG. 6 is a flowchart of a program for a microcomputer in
the IC card of FIG. 3.
[0023] FIGS. 7 and 8 are diagrams of signals transmitted between
the reader/writer and IC cards in FIG. 1.
DESCRIPTION OF THE PREFERRED EMBODIMENT
[0024] With reference to FIG. 1, a contactless IC card control
system includes a reader/writer RW provided on, for example, a
telephone set. A given communication service area (a given
communication coverage) provided by the reader/writer RW extends
therefrom. Under exemplary conditions shown in FIG. 1, three IC
cards "A", "B", and "C" are placed in the communication service
area. For example, the IC cards "A", "B", and "C" are prepaid cards
for using a telephone set. The reader/writer RW can communicate
with the IC cards "A", "B", and "C" by radio.
[0025] As shown in FIG. 2, the reader/writer RW includes a
microcomputer 10, a memory 20, a modulation circuit 30, an antenna
40, and a demodulation circuit 50. The modulation circuit 30 and
the demodulation circuit 50 are connected to the antenna 40. The
microcomputer 10 is connected to the memory 20, the modulation
circuit 30, and the demodulation circuit 50. The microcomputer 10
is electrically connected to, for example, a telephone set.
[0026] The microcomputer 10 includes a combination of an
input/output port, a CPU, a ROM, and a RAM. The microcomputer 10
operates in accordance with a program stored in the ROM. The
program has a first segment for implementing radio communications
with each IC card placed in the communication service area. The
program has a second segment for detecting or identifying the type
of each IC card. The program has a third segment for assigning a
logical address to each IC card. The program has a fourth segment
for canceling the assignment of a logical address to a designated
IC card. The program has a fifth segment for controlling each IC
card.
[0027] The memory 20 is previously loaded with data representing at
least two different logical addresses (that is, a logical address
"1" and a logical address "2"). The memory 20 can be accessed by
the microcomputer 10.
[0028] The modulation circuit 30 receives output data (a baseband
signal) from the microcomputer 10. The modulation circuit 30
subjects the output data from the microcomputer 10 to modulation,
thereby converting the data (the baseband signal) into a radio
signal. The modulation circuit 30 outputs the radio signal to the
antenna 40. The radio signal is radiated by the antenna 40.
[0029] A radio signal coming from each IC card in the communication
service area is received by the antenna 40. The received radio
signal is fed from the antenna 40 to the demodulation circuit 50.
The demodulation circuit 50 subjects the received radio signal to
demodulation, thereby recovering baseband data therefrom. The
demodulation circuit 50 outputs the recovered data to the
microcomputer 10.
[0030] The IC cards "A", "B", and "C" are similar in structure.
Accordingly, only the structure of the IC card "A" will be
explained in detail. As shown in FIG. 3, the IC card "A" includes
an antenna 60, a power supply circuit 70, a demodulation circuit
80, a memory 90, a microcomputer 100, and a modulation circuit 110.
The antenna 60 is connected to the power supply circuit 70, the
demodulation circuit 80, and the modulation circuit 110. The
microcomputer 100 is connected to the demodulation circuit 80, the
memory 90, and the modulation circuit 110.
[0031] A radio signal coming from the reader/writer RW is received
by the antenna 60. The received radio signal is fed from the
antenna 60 to the power supply circuit 70 and the demodulation
circuit 80. The power supply circuit 70 generates DC power from the
received radio signal, and stores the generated DC power. In
addition, the power supply circuit 70 feeds the DC power to the
demodulation circuit 80, the memory 90, the microcomputer 100, and
the modulation circuit 110 to activate them.
[0032] The demodulation circuit 80 subjects the received radio
signal to demodulation, thereby recovering baseband data therefrom.
The demodulation circuit 80 outputs the recovered data to the
microcomputer 100.
[0033] The memory 90 is previously loaded with IC-card
identification data or IC-card identification information (IC-card
ID information). Specifically, the IC-card ID information includes
data representing an ID code word corresponding to a type of the
related IC card (the IC card "A"), and data representing parameters
of the related IC card (the IC card "A"). The memory 90 can be
accessed by the microcomputer 100.
[0034] The microcomputer 100 includes a combination of an
input/output port, a CPU, a ROM, and a RAM. The microcomputer 100
operates in accordance with a program stored in the ROM. The
program has a segment for implementing radio communications with
the reader/writer RW.
[0035] The modulation circuit 110 receives output data (a baseband
signal) from the microcomputer 100. The modulation circuit 110
subjects the output data from the microcomputer 100 to modulation,
thereby converting the data (the baseband signal) into a radio
signal. The modulation circuit 10 outputs the radio signal to the
antenna 60. The radio signal is radiated by the antenna 60.
[0036] The IC card "B" is similar to the IC card "A" except that
the memory 90 in the IC card "B" stores data representing an ID
code word corresponding to a type of the IC card "B", and data
representing parameters of the IC card "B". The IC card "C" is
similar to the IC card "A" except that the memory 90 in the IC card
"C" stores data representing an ID code word corresponding to a
type of the IC card "C", and data representing parameters of the IC
card "C".
[0037] The program in the microcomputer 100 of the IC card "B" is
similar to that in the microcomputer 100 of the IC card "A". In
addition, the program in the microcomputer 100 of the IC card "C"
is similar to that in the microcomputer 100 of the IC card "A".
[0038] The contactless IC card control system operates as follows.
It is assumed that as shown in FIG. 1, the IC cards "A", "B", and
"C" exist in the communication service area provided by the
reader/writer RW.
[0039] In the reader/writer RW, the microcomputer 10 outputs a
signal Drw (see FIG. 7) of a requirement for IC-card ID information
to the modulation circuit 30. The modulation circuit 30 converts
the ID information requirement signal Drw into a corresponding
command radio signal referred to as a first command radio signal.
The modulation circuit 30 outputs the first command radio signal to
the antenna 40.
[0040] The first command radio signal is radiated by the antenna
40, being transmitted from the reader/writer RW to the IC cards
"A", "B", and "C".
[0041] In each of the IC cards "A", "B", and "C", the first command
radio signal is received by the antenna 60. The received first
command radio signal is fed from the antenna 60 to the demodulation
circuit 80. The demodulation circuit 80 recovers the ID information
requirement signal Drw from the received first command radio
signal. The demodulation circuit 80 outputs the recovered ID
information requirement signal Drw to the microcomputer 100.
[0042] In each of the IC cards "A", "B", and "C", the microcomputer
100 reads out the ID data from the memory 90 in response to the ID
information requirement signal Drw, and generates an answer signal
Da, Db, or Dc (see FIG. 7) from the readout data. The microcomputer
100 outputs the answer signal Da, Db, or Dc (see FIG. 7) to the
modulation circuit 110. The answer signal Da, Db, or Dc contains
the ID information of the related IC card.
[0043] Specifically, the answer signal Da outputted from the
microcomputer 100 in the IC card "A" represents the ID code word
corresponding to the IC card "A". The answer signal Db outputted
from the microcomputer 100 in the IC card "B" represents the ID
code word corresponding to the IC card "B". The answer signal Dc
outputted from the microcomputer 100 in the IC card "C" represents
the ID code word corresponding to the IC card "C".
[0044] In the IC card "A", the modulation circuit 110 converts the
ID information answer signal Da into a corresponding radio answer
signal RSa. The modulation circuit 110 feeds the radio answer
signal RSa to the antenna 60. The antenna 60 radiates and transmits
the radio answer signal RSa.
[0045] In the IC card "B", the modulation circuit 110 converts the
ID information answer signal Db into a corresponding radio answer
signal RSb. The modulation circuit 110 feeds the radio answer
signal RSb to the antenna 60. The antenna 60 radiates and transmits
the radio answer signal RSb.
[0046] In the IC card "C", the modulation circuit 110 converts the
ID information answer signal Dc into a corresponding radio answer
signal RSc. The modulation circuit 110 feeds the radio answer
signal RSc to the antenna 60. The antenna 60 radiates and transmits
the radio answer signal RSc.
[0047] The antenna 40 in the reader/writer RW receives the radio
answer signals RSa, RSb, and RSc from the IC cards "A", "B", and
"C". It is assumed that the radio answer signals RSa, RSb, and RSc
are sequentially received by the reader/writer RW in that order. In
the reader/writer RW, the received radio answer signals RSa, RSb,
and RSc are fed from the antenna 40 to the demodulation circuit 50.
The demodulation circuit 50 recovers the ID information answer
signals Da, Db, and Dc from the radio answer signals RSa, RSb, and
RSc, respectively. The demodulation circuit 50 outputs the
recovered ID information answer signals Da, Db, and Dc to the
microcomputer 10. In response to the recovered ID information
answer signals Da, Db, and Dc, the microcomputer decides that IC
cards are present in the communication service area, and answers to
the ID information requirement have come therefrom. The recovered
ID information answer signals Da, Db, and Dc represent the ID code
words of the IC cards "A", "B", and "C", respectively. Accordingly,
the demodulation circuit 50 informs the microcomputer 10 of the
recovered ID code words of the IC cards "A", "B", and "C". The
microcomputer 10 sets flags for the respective recovered ID code
words. The microcomputer 10 uses each of the recovered ID code
words as IC-card ID information. The microcomputer 10 writes
signals (data) of the recovered ID code words into the memory 20 as
IC-card ID information.
[0048] Subsequently, the microcomputer 10 in the reader/writer RW
assigns the logical addresses "1" and "2" to the IC cards "A" and
"B" as follows. The microcomputer 10 reads out the data from the
memory 20 which represents the logical address "1" and the ID code
word (the ID information) of the IC card "A". The microcomputer 10
generates a selection requirement signal Srwa for the IC card "A"
in response to the readout data. As shown in FIG. 7, the selection
requirement signal Srwa has a sequence of a selection command, the
logical address "1", and the ID information of the IC card "A". The
microcomputer 10 outputs the selection requirement signal Srwa to
the modulation circuit 30. The modulation circuit 30 converts the
selection requirement signal Srwa into a corresponding command
radio signal referred to as a second command radio signal. The
modulation circuit 30 outputs the second command radio signal to
the antenna 40. The second command radio signal is radiated by the
antenna 40, being transmitted from the reader/writer RW.
[0049] In the IC card "A", the second command radio signal is
received by the antenna 60. The received second command radio
signal is fed from the antenna 60 to the demodulation circuit 80.
The demodulation circuit 80 recovers the selection requirement
signal Srwa from the received second command radio signal. The
demodulation circuit 80 outputs the recovered selection requirement
signal Srwa to the microcomputer 100. The microcomputer 100 detects
that the recovered selection requirement signal Srwa is directed to
the IC card "A" on the basis of the ID information in the recovered
selection requirement signal Srwa. In addition, the microcomputer
100 decides, from the recovered selection requirement signal Srwa,
that the logical address "1" is assigned to the related IC card
(the IC card "A"). The microcomputer 100 generates data
representing that the logical address "1" is assigned to the
related IC card (the IC card "A"). The microcomputer 100 writes the
generated data into the memory 90. Furthermore, the microcomputer
100 generates an assignment answer signal Sa in response to the
selection requirement signal Srwa. As shown in FIG. 7, the
assignment answer signal Sa has a sequence of an assignment
response code word and the logical address "1". The microcomputer
100 outputs the assignment answer signal Sa to the modulation
circuit 110. The modulation circuit 110 converts the assignment
answer signal Sa into a corresponding radio answer signal RTa. The
modulation circuit 110 feeds the radio answer signal RTa to the
antenna 60. The antenna 60 radiates and transmits the radio answer
signal RTa.
[0050] The antenna 40 in the reader/writer RW receives the radio
answer signal RTa from the IC card "A". In the reader/writer RW,
the received radio answer signal RTa is fed from the antenna 40 to
the demodulation circuit 50. The demodulation circuit 50 recovers
the assignment answer signal Sa from the received radio answer
signal RTa. The demodulation circuit 50 outputs the recovered
assignment answer signal Sa to the microcomputer 10. The
microcomputer 10 sets an assignment-indicating flag for the logical
address "1" in response to the recovered assignment answer signal
Sa. Specifically, the microcomputer 10 generates data representing
that the logical address "1" has been assigned to the IC card "A".
The microcomputer 10 writes the generated data into the memory
20.
[0051] Subsequently, the microcomputer 10 in the reader/writer RW
reads out the data from the memory 20 which represents the logical
address "2" and the ID code word (the ID information) of the IC
card "B". The microcomputer 10 generates a selection requirement
signal Srwb for the IC card "B" in response to the readout data. As
shown in FIG. 7, the selection requirement signal Srwb has a
sequence of the selection command, the logical address "2", and the
ID information of the IC card "B". The microcomputer 10 outputs the
selection requirement signal Srwb to the modulation circuit 30. The
modulation circuit 30 converts the selection requirement signal
Srwb into a corresponding command radio signal referred to as a
third command radio signal. The modulation circuit 30 outputs the
third command radio signal to the antenna 40. The third command
radio signal is radiated by the antenna 40, being transmitted from
the reader/writer RW.
[0052] In the IC card "B", the third command radio signal is
received by the antenna 60. The received third command radio signal
is fed from the antenna 60 to the demodulation circuit 80. The
demodulation circuit 80 recovers the selection requirement signal
Srwb from the received third command radio signal. The demodulation
circuit 80 outputs the recovered selection requirement signal Srwb
to the microcomputer 100. The microcomputer 100 detects that the
recovered selection requirement signal Srwb is directed to the IC
card "B" on the basis of the ID information in the recovered
selection requirement signal Srwb. In addition, the microcomputer
100 decides, from the recovered selection requirement signal Srwb,
that the logical address "2" is assigned to the related IC card
(the IC card "B"). The microcomputer 100 generates data
representing that the logical address "2" is assigned to the
related IC card (the IC card "B"). The microcomputer 100 writes the
generated data into the memory 90. Furthermore, the microcomputer
100 generates an assignment answer signal Sb in response to the
selection requirement signal Srwb. As shown in FIG. 7, the
assignment answer signal Sb has a sequence of the assignment
response code word and the logical address "2". The microcomputer
100 outputs the assignment answer signal Sb to the modulation
circuit 110. The modulation circuit 110 converts the assignment
answer signal Sb into a corresponding radio answer signal RTb. The
modulation circuit 110 feeds the radio answer signal RTb to the
antenna 60. The antenna 60 radiates and transmits the radio answer
signal RTb.
[0053] The antenna 40 in the reader/writer RW receives the radio
answer signal RTb from the IC card "B". In the reader/writer RW,
the received radio answer signal RTb is fed from the antenna 40 to
the demodulation circuit 50. The demodulation circuit 50 recovers
the assignment answer signal Sb from the received radio answer
signal RTb. The demodulation circuit 50 outputs the recovered
assignment answer signal Sb to the microcomputer 10. The
microcomputer 10 sets an assignment-indicating flag for the logical
address "2" in response to the recovered assignment answer signal
Sb. Specifically, the microcomputer 10 generates data representing
that the logical address "2" has been assigned to the IC card "B".
The microcomputer 10 writes the generated data into the memory
20.
[0054] After both the logical addresses "1" and "2" have been
assigned to the IC cards "A" and "B", the microcomputer 10 in the
reader/writer RW implements steps of controlling the IC cards "A"
and "B" as follows. The microcomputer 10 generates a read
requirement signal Rrwa for the IC card "A". As shown in FIG. 7,
the read requirement signal Rrwa has a sequence of a read command,
the logical address "1", and read requirement information. The
microcomputer 10 outputs the read requirement signal Rrwa to the
modulation circuit 30. The modulation circuit 30 converts the read
requirement signal Rrwa into a corresponding command radio signal
referred to as a fourth command radio signal. The modulation
circuit 30 outputs the fourth command radio signal to the antenna
40. The fourth command radio signal is radiated by the antenna 40,
being transmitted from the reader/writer RW.
[0055] In the IC card "A", the fourth command radio signal is
received by the antenna 60. The received fourth command radio
signal is fed from the antenna 60 to the demodulation circuit 80.
The demodulation circuit 80 recovers the read requirement signal
Rrwa from the received fourth command radio signal. The
demodulation circuit 80 outputs the recovered read requirement
signal Rrwa to the microcomputer 100. The microcomputer 100 detects
that the logical address represented by the recovered read
requirement signal Rrwa agrees with the logical address "1"
assigned to the related IC card (the IC card "A"). Thus, the
microcomputer 100 recognizes that the recovered read requirement
signal Rrwa is directed to the related IC card (the IC card "A").
Subsequently, the microcomputer 100 reads out data from the memory
90 in response to the read command and the read requirement
information represented by the recovered read requirement signal
Rrwa. Specifically, the readout data is designated by the read
requirement information. The microcomputer 100 uses the readout
data as read information. The microcomputer 100 generates a read
answer signal Ra. As shown in FIG. 7, the read answer signal Ra has
a sequence of a read response code word, the logical address "1",
and the read information. The microcomputer 100 outputs the read
answer signal Ra to the modulation circuit 110. The modulation
circuit 110 converts the read answer signal Ra into a corresponding
radio answer signal RUa. The modulation circuit 110 feeds the radio
answer signal RUa to the antenna 60. The antenna 60 radiates and
transmits the radio answer signal RUa.
[0056] The antenna 40 in the reader/writer RW receives the radio
answer signal RUa from the IC card "A". In the reader/writer RW,
the received radio answer signal RUa is fed from the antenna 40 to
the demodulation circuit 50. The demodulation circuit 50 recovers
the read answer signal Ra from the received radio answer signal
RUa. The demodulation circuit 50 outputs the recovered read answer
signal Ra to the microcomputer 10. The microcomputer 10 extracts
the read information from the recovered read answer signal Ra. The
microcomputer 10 writes the read information into the memory 20 as
readout data.
[0057] Subsequently, the microcomputer 10 generates a read
requirement signal Rrwb for the IC card "B". As shown in FIG. 7,
the read requirement signal Rrwb has a sequence of the read
command, the logical address "2", and read requirement information.
The microcomputer 10 outputs the read requirement signal Rrwb to
the modulation circuit 30. The modulation circuit 30 converts the
read requirement signal Rrwb into a corresponding command radio
signal referred to as a fifth command radio signal. The modulation
circuit 30 outputs the fifth command radio signal to the antenna
40. The fifth command radio signal is radiated by the antenna 40,
being transmitted from the reader/writer RW.
[0058] In the IC card "B", the fifth command radio signal is
received by the antenna 60. The received fifth command radio signal
is fed from the antenna 60 to the demodulation circuit 80. The
demodulation circuit 80 recovers the read requirement signal Rrwb
from the received fifth command radio signal. The demodulation
circuit 80 outputs the recovered read requirement signal Rrwb to
the microcomputer 100. The microcomputer 100 detects that the
logical address represented by the recovered read requirement
signal Rrwb agrees with the logical address "2" assigned to the
related IC card (the IC card "B"). Thus, the microcomputer 100
recognizes that the recovered read requirement signal Rrwb is
directed to the related IC card (the IC card "B"). Subsequently,
the microcomputer 100 reads out data from the memory 90 in response
to the read command and the read requirement information
represented by the recovered read requirement signal Rrwb.
Specifically, the readout data is designated by the read
requirement information. The microcomputer 100 uses the readout
data as read information. The microcomputer 100 generates a read
answer signal Rb. As shown in FIG. 7, the read answer signal Rb has
a sequence of the read response code word, the logical address "2",
and the read information. The microcomputer 100 outputs the read
answer signal Rb to the modulation circuit 110. The modulation
circuit 110 converts the read answer signal Rb into a corresponding
radio answer signal RUb. The modulation circuit 110 feeds the radio
answer signal RUb to the antenna 60. The antenna 60 radiates and
transmits the radio answer signal RUb.
[0059] The antenna 40 in the reader/writer RW receives the radio
answer signal RUb from the IC card "B". In the reader/writer RW,
the received radio answer signal RUb is fed from the antenna 40 to
the demodulation circuit 50. The demodulation circuit 50 recovers
the read answer signal Rb from the received radio answer signal
RUb. The demodulation circuit 50 outputs the recovered read answer
signal Rb to the microcomputer 10. The microcomputer 10 extracts
the read information from the recovered read answer signal Rb. The
microcomputer 10 writes the read information into the memory 20 as
readout data.
[0060] After the steps of controlling the IC cards "A" and "B" have
been completed, the microcomputer 10 cancels the assignment of the
logical address "1" to the IC card "A" as follows. The
microcomputer 10 generates an address cancel requirement signal Lrw
for the IC card "A". As shown in FIG. 8, the address cancel
requirement signal Lrw has a sequence of a cancel command and the
logical address "1" which corresponds to an object to be canceled.
The microcomputer 10 outputs the address cancel requirement signal
Lrw to the modulation circuit 30. The modulation circuit 30
converts the address cancel requirement signal Lrw into a
corresponding command radio signal referred to as a sixth command
radio signal. The modulation circuit 30 outputs the sixth command
radio signal to the antenna 40. The sixth command radio signal is
radiated by the antenna 40, being transmitted from the
reader/writer RW.
[0061] In the IC card "A", the sixth command radio signal is
received by the antenna 60. The received sixth command radio signal
is fed from the antenna 60 to the demodulation circuit 80. The
demodulation circuit 80 recovers the address cancel requirement
signal Lrw from the received sixth command radio signal. The
demodulation circuit 80 outputs the recovered address cancel
requirement signal Lrw to the microcomputer 100. The microcomputer
100 detects that the logical address represented by the recovered
address cancel requirement signal Lrw agrees with the logical
address assigned to the related IC card (the IC card "A").
Accordingly, the microcomputer 100 decides that the recovered
address cancel requirement signal Lrw is directed to the related IC
card (the IC card "A"). The microcomputer 100 cancels the
assignment of the logical address "1" to the related IC card (the
IC card "A") in response to the recovered address cancel signal
Lrw. Specifically, the microcomputer 100 erases the data from the
memory 90 which represents that the logical address "1" is assigned
to the related IC card (the IC card "A"). In addition, the
microcomputer 100 generates an address cancel answer signal La. As
shown in FIG. 8, the address cancel answer signal La has a sequence
of a cancel response code word and the logical address "1". The
microcomputer 100 outputs the address cancel answer signal La to
the modulation circuit 110. The modulation circuit 110 converts the
address cancel answer signal La into a corresponding radio answer
signal RVa. The modulation circuit 110 feeds the radio answer
signal RVa to the antenna 60. The antenna 60 radiates and transmits
the radio answer signal RVa.
[0062] The antenna 40 in the reader/writer RW receives the radio
answer signal RVa from the IC card "A". In the reader/writer RW,
the received radio answer signal RVa is fed from the antenna 40 to
the demodulation circuit 50. The demodulation circuit 50 recovers
the address cancel answer signal La from the received radio answer
signal RVa. The demodulation circuit 50 outputs the recovered
address cancel answer signal La to the microcomputer 10. The
microcomputer 10 resets the assignment-indicating flag for the
logical address "1" in response to the recovered address cancel
answer signal La. Specifically, the microcomputer 10 erases the
data from the memory 20 which represents that the logical address
"1" has been assigned to the IC card "A". In this way, the
assignment of the logical address "1" to the IC card "A" is
canceled.
[0063] Subsequently, the microcomputer 10 in the reader/writer RW
assigns the logical address "1" to the IC card "C" as follows. The
microcomputer 10 reads out the data from the memory 20 which
represents the logical address "1" and the ID code word (the ID
information) of the IC card "C". The microcomputer 10 generates a
selection requirement signal Srwc for the IC card "C" in response
to the readout data. As shown in FIG. 8, the selection requirement
signal Srwc has a sequence of the selection command, the logical
address "1", and the ID information of the IC card "C". The
microcomputer 10 outputs the selection requirement signal Srwc to
the modulation circuit 30. The modulation circuit 30 converts the
selection requirement signal Srwc into a corresponding command
radio signal referred to as a seventh command radio signal. The
modulation circuit 30 outputs the seventh command radio signal to
the antenna 40. The seventh command radio signal is radiated by the
antenna 40, being transmitted from the reader/writer RW.
[0064] In the IC card "C", the seventh command radio signal is
received by the antenna 60. The received seventh command radio
signal is fed from the antenna 60 to the demodulation circuit 80.
The demodulation circuit 80 recovers the selection requirement
signal Srwc from the received seventh command radio signal. The
demodulation circuit 80 outputs the recovered selection requirement
signal Srwc to the microcomputer 100. The microcomputer 100 detects
that the recovered selection requirement signal Srwc is directed to
the IC card "C" on the basis of the ID information in the recovered
selection requirement signal Srwc. In addition, the microcomputer
100 decides, from the recovered selection requirement signal Srwc,
that the logical address "1" is assigned to the related IC card
(the IC card "C"). The microcomputer 100 generates data
representing that the logical address "1" is assigned to the
related IC card (the IC card "C"). The microcomputer 100 writes the
generated data into the memory 90. Furthermore, the microcomputer
100 generates an assignment answer signal Sc in response to the
selection requirement signal Srwc. As shown in FIG. 8, the
assignment answer signal Sc has a sequence of the assignment
response code word and the logical address "1". The microcomputer
100 outputs the assignment answer signal Sc to the modulation
circuit 110. The modulation circuit 110 converts the assignment
answer signal Sc into a corresponding radio answer signal RTc. The
modulation circuit 110 feeds the radio answer signal RTc to the
antenna 60. The antenna 60 radiates and transmits the radio answer
signal RTc.
[0065] The antenna 40 in the reader/writer RW receives the radio
answer signal RTc from the IC card "C". In the reader/writer RW,
the received radio answer signal RTc is fed from the antenna 40 to
the demodulation circuit 50. The demodulation circuit 50 recovers
the assignment answer signal Sc from the received radio answer
signal RTc. The demodulation circuit 50 outputs the recovered
assignment answer signal Sc to the microcomputer 10. The
microcomputer 10 sets the assignment-indicating flag for the
logical address "1" in response to the recovered assignment answer
signal Sc. Specifically, the microcomputer 10 generates data
representing that the logical address "1" has been assigned to the
IC card "C". The microcomputer 10 writes the generated data into
the memory 20.
[0066] Subsequently, the microcomputer 10 in the reader/writer RW
implements steps of controlling the IC card "C" as follows. The
microcomputer 10 generates a read requirement signal Rrwc for the
IC card "C". As shown in FIG. 8, the read requirement signal Rrwc
has a sequence of the read command, the logical address "1", and
read requirement information. The microcomputer 10 outputs the read
requirement signal Rrwc to the modulation circuit 30. The
modulation circuit 30 converts the read requirement signal Rrwc
into a corresponding command radio signal referred to as an eighth
command radio signal. The modulation circuit 30 outputs the eighth
command radio signal to the antenna 40. The eighth command radio
signal is radiated by the antenna 40, being transmitted from the
reader/writer RW.
[0067] In the IC card "C", the eighth command radio signal is
received by the antenna 60. The received eighth command radio
signal is fed from the antenna 60 to the demodulation circuit 80.
The demodulation circuit 80 recovers the read requirement signal
Rrwc from the received eighth command radio signal. The
demodulation circuit 80 outputs the recovered read requirement
signal Rrwc to the microcomputer 100. The microcomputer 100 detects
that the logical address represented by the recovered read
requirement signal Rrwc agrees with the logical address "1"
assigned to the related IC card (the IC card "C"). Thus, the
microcomputer 100 recognizes that the recovered read requirement
signal Rrwc is directed to the related IC card (the IC card "C").
Subsequently, the microcomputer 100 reads out data from the memory
90 in response to the read command and the read requirement
information represented by the recovered read requirement signal
Rrwc. Specifically, the readout data is designated by the read
requirement information. The microcomputer 100 uses the readout
data as read information. The microcomputer 100 generates a read
answer signal Rc. As shown in FIG. 8, the read answer signal Rc has
a sequence of the read response code word, the logical address "1",
and the read information. The microcomputer 100 outputs the read
answer signal Rc to the modulation circuit 110. The modulation
circuit 110 converts the read answer signal Rc into a corresponding
radio answer signal RUc. The modulation circuit 110 feeds the radio
answer signal RUc to the antenna 60. The antenna 60 radiates and
transmits the radio answer signal RUc.
[0068] The antenna 40 in the reader/writer RW receives the radio
answer signal RUc from the IC card "C". In the reader/writer RW,
the received radio answer signal RUc is fed from the antenna 40 to
the demodulation circuit 50. The demodulation circuit 50 recovers
the read answer signal Rc from the received radio answer signal
RUc. The demodulation circuit 50 outputs the recovered read answer
signal Rc to the microcomputer 10. The microcomputer 10 extracts
the read information from the recovered read answer signal Rc. The
microcomputer 10 writes the read information into the memory 20 as
readout data.
[0069] As previously indicated, the microcomputer 10 in the
reader/writer RW operates in accordance with a program stored in
its internal ROM. FIGS. 4 and 5 are a flowchart of the program in
the microcomputer 10.
[0070] As shown in FIG. 4, a first step 200 of the program outputs
an ID information requirement signal Drw to the modulation circuit
30. After the step 200, the program advances to a step 210.
[0071] The step 210 decides whether or not at least one ID
information answer signal is present during a given time interval
from the moment of the outputting of the ID information requirement
signal Drw. When at least one ID information answer signal is
present, the program advances from the step 210 to a step 211.
Otherwise, the program exits from the step 210, and then the
current execution cycle of the program ends (see FIG. 5).
[0072] The step 211 sets flags for ID code words represented by the
ID information answer signals respectively. The step 211 writes
signals (data) of the ID code words into the memory 20 as IC-card
ID information. After the step 211, the program advances to a step
212.
[0073] The step 212 reads out the data from the memory 20 which
represents the logical address "1" and the ID code word (the ID
information) of the first IC card, for example, the IC card "A".
The step 212 generates a selection requirement signal Srwa for the
first IC card (the IC card "A") in response to the readout data.
The step 212 outputs the selection requirement signal Srwa to the
modulation circuit 30.
[0074] A step 213 following the step 212 awaits an assignment
answer signal Sa which is responsive to the selection requirement
signal Srwa. The step 213 sets an assignment-indicating flag for
the logical address "1" when detecting the assignment answer signal
Sa. Specifically, in response to the assignment answer signal Sa,
the step 213 generates data representing that the logical address
"1" has been assigned to the first IC card (the IC card "A"). The
step 213 writes the generated data into the memory 20. Thus, the
assignment of the logical address "1" to the first IC card (the IC
card "A") is completed.
[0075] A step 220 subsequent to the step 213 decides whether or not
there is at least one IC card to which a logical address has not
been assigned yet. When there is at least one IC card to which a
logical address has not been assigned yet, the program advances
from the step 220 to a step 230. Otherwise, the program jumps from
the step 220 to a step 240.
[0076] The step 230 decides whether or not the assignment of a
logical address to a remaining IC card is possible. When the
assignment of a logical address to a remaining IC card is possible,
the program returns from the step 230 to the step 212. Otherwise,
the program advances from the step 230 to the step 240.
[0077] In the case where the assignment of the logical address "2"
to the second IC card (for example, the IC card "B") is possible,
the program returns from the step 230 to the step 212. In this
case, the step 212 reads out the data from the memory 20 which
represents the logical address "2" and the ID code word (the ID
information) of the second IC card, for example, the IC card "B".
The step 212 generates a selection requirement signal Srwb for the
second IC card (the IC card "B") in response to the readout data.
The step 212 outputs the selection requirement signal Srwb to the
modulation circuit 30.
[0078] The step 213 which follows the step 212 awaits an assignment
answer signal Sb responding to the selection requirement signal
Srwb. The step 213 sets an assignment-indicating flag for the
logical address "2" when detecting the assignment answer signal Sb.
Specifically, in response to the assignment answer signal Sb, the
step 213 generates data representing that the logical address "2"
has been assigned to the second IC card (the IC card "B"). The step
213 writes the generated data into the memory 20. Thus, the
assignment of the logical address "2" to the second IC card (the IC
card "B") is completed.
[0079] The step 220 subsequent to the step 213 decides whether or
not there is at least one IC card to which a logical address has
not been assigned yet. When there is at least one IC card to which
a logical address has not been assigned yet, the program advances
from the step 220 to the step 230. Otherwise, the program jumps
from the step 220 to the step 240.
[0080] The step 230 decides whether or not the assignment of a
logical address to a remaining IC card is possible. When the
assignment of a logical address to a remaining IC card is possible,
the program returns from the step 230 to the step 212. Otherwise,
the program advances from the step 230 to the step 240.
[0081] In the case where the logical addresses "1" and "2" have
been assigned to the first and second IC cards (the IC cards "A"
and "B") respectively, the program advances from the step 230 to
the step 240.
[0082] The step 240 decides whether or not the execution of a
command to control the first IC card (the IC card "A") is required.
When the execution of the command to control the first IC card (the
IC card "A") is required, the program advances from the step 240 to
a step 241. In addition, the step 240 decides whether or not the
execution of a command to control the second IC card (the IC card
"B") is required. When the execution of the command to control the
second IC card (the IC card "B") is required, the program advances
from the step 240 to the step 241. When neither the execution of
the command to control the first IC card (the IC card "A") nor the
execution of the command to control the second IC card (the IC card
"B") is required, the program advances from the step 240 to a step
260 in FIG. 5.
[0083] The step 241 executes the command to control the first IC
card (the IC card "A") or the command to control the second IC card
(the IC card "B"). In the case of the execution of the command to
control the first IC card (the IC card "A"), the step 241 generates
a read requirement signal Rrwa for the first IC card. The step 241
outputs the read requirement signal Rrwa to the modulation circuit
30. In the case of the execution of the command to control the
second IC card (the IC card "B"), the step 241 generates a read
requirement signal Rrwb for the second IC card. The step 241
outputs the read requirement signal Rrwb to the modulation circuit
30. In addition, the step 241 awaits a read answer signal Ra or Rb
which is responsive to the read requirement signal Rrwa or Rrwb.
Upon the detection of the read answer signal Ra or Rb, the step 241
extracts the read information from the read answer signal Ra or Rb.
The step 241 writes the read information into the memory 20 as
readout data.
[0084] A step 250 following the step 241 decides whether or not the
execution of all the commands to control the respective
address-assigned IC cards has been completed. When the execution of
all the commands has been completed, the program advances from the
step 250 to the step 260 in FIG. 5. Otherwise, the program returns
from the step 250 to the step 240.
[0085] The step 260 decides whether or not a command to control the
remaining IC card (the third IC card, for example, the IC card
"C"), to which any logical address has not been assigned yet, is
required to be executed. When the command to control the third IC
card is required to be executed, the program advances from the step
260 to a step 261. Otherwise, the program exits from the step 260,
and then the current execution cycle of the program ends.
[0086] The step 261 generates an address cancel requirement signal
Lrw for the fist IC card (the IC card "A") to which the logical
address "1" has been assigned. The step 261 outputs the address
cancel requirement signal Lrw to the modulation circuit 30. In
addition, the step 261 awaits an address cancel answer signal La
which is responsive to the address cancel requirement signal Lrw.
The step 261 resets the assignment-indicating flag for the logical
address "1" when detecting the address cancel answer signal La.
Specifically, the step 261 erases the data from the memory 20 which
represents that the logical address "1" has been assigned to the
first IC card (the IC card "A").
[0087] A step 262 subsequent to the step 261 reads out the data
from the memory 20 which represents the logical address "1" and the
ID code word (the ID information) of the third IC card, for
example, the IC card "C". The step 262 generates a selection
requirement signal Srwc for the third IC card (the IC card "C") in
response to the readout data. The step 262 outputs the selection
requirement signal Srwc to the modulation circuit 30.
[0088] A step 263 following the step 262 awaits an assignment
answer signal Sc which is responsive to the selection requirement
signal Srwc. The step 263 sets the assignment-indicating flag for
the logical address "1" when detecting the assignment answer signal
Sc. Specifically, in response to the assignment answer signal Sc,
the step 263 generates data representing that the logical address
"1" has been assigned to the third IC card (the IC card "C"). The
step 263 writes the generated data into the memory 20. Thus, the
assignment of the logical address "1" to the third IC card (the IC
card "C") is completed.
[0089] A step 264 subsequent to the step 263 executes a command to
control the third IC card (the IC card "C"). Specifically, the step
264 generates a read requirement signal Rrwc for the third IC card.
The step 264 outputs the read requirement signal Rrwc to the
modulation circuit 30. In addition, the step 264 awaits a read
answer signal Rc which is responsive to the read requirement signal
Rrwc. When the read answer signal Rc is received, the step 264
extracts the read information from the read answer signal Rc. The
step 264 writes the read information into the memory 20 as readout
data. After the step 264, the current execution cycle of the
program ends.
[0090] As previously indicated, the microcomputer 100 in the IC
card "A" operates in accordance with a program stored in its
internal ROM. FIG. 6 is a flowchart of the program in the
microcomputer 100.
[0091] As shown in FIG. 6, a first step 300 of the program decides
whether or not an ID information requirement signal Drw is present.
When the ID information requirement signal Drw is present, the
program advances from the step 300 to a step 310. Otherwise, the
step 300 is repeated.
[0092] The step 310 reads out the ID data from the memory 90. The
step 310 generates an ID information answer signal Da from the
readout data. The step 310 outputs the ID information answer signal
Da to the modulation circuit 110. After the step 310, the program
advances to a step 320.
[0093] The step 320 decides whether or not a selection requirement
signal Srwa directed to the IC card "A" is present by referring to
the ID code word (the ID information) in the selection requirement
signal Srwa. When the selection requirement signal Srwa is present,
the program advances from the step 320 to a step 330. Otherwise,
the step 320 is repeated.
[0094] The step 330 decides, from the recovered selection
requirement signal Srwa, that the logical address "1" is assigned
to the IC card "A". The step 330 generates data representing that
the logical address "1" is assigned to the IC card "A". The step
330 writes the generated data into the memory 90. Furthermore, the
step 330 generates an assignment answer signal Sa in response to
the selection requirement signal Srwa. The step 330 outputs the
assignment answer signal Sa to the modulation circuit 110. After
the step 330, the program advances to a step 340.
[0095] The step 340 decides whether or not a command to control an
IC card (for example, the IC card "A") is present. An example of
the command is a read requirement signal (a read requirement signal
Rrwa). When the command is present, the program advances from the
step 340 to a step 350. Otherwise, the step 340 is repeated.
[0096] The step 350 decides whether or not the logical address
represented by the command (for example, the read requirement
signal) agrees with the logical address "1" assigned to the IC card
"A". In other words, the step 350 decides whether or not the
command is directed to the IC card "A". When the logical address
represented by the command agrees with the logical address "1",
that is, when the command is directed to the IC card "A", the
program advances from the step 350 to a step 360. Otherwise, the
program returns from the step 350 to the step 340.
[0097] The step 360 decides whether the command is equal to or
different from an address cancel requirement signal Lrw. When the
command is different from the address cancel requirement signal
Lrw, the program advances from the step 360 to a step 370. When the
command is equal to the address cancel requirement signal Lrw, the
program advances from the step 360 to a step 380.
[0098] The step 370 executes the command. In the case where the
command is equal to the read requirement signal Rrwa, the step 370
reads out data from the memory 90 in response to the read command
and the read requirement information represented by the read
requirement signal Rrwa. Specifically, the readout data is
designated by the read requirement information. The step 370 uses
the readout data as read information. The step 370 generates a read
answer signal Ra. The step 370 outputs the read answer signal Ra to
the modulation circuit 110. After the step 370, the program returns
to the step 340.
[0099] The step 380 cancels the assignment of the logical address
"1" to the IC card "A" in response to the address cancel signal
Lrw. Specifically, the step 380 erases the data from the memory 90
which represents that the logical address "1" is assigned to the IC
card "A". In addition, the step 380 generates an address cancel
answer signal La. The step 380 outputs the address cancel answer
signal La to the modulation circuit 110. After the step 380, the
program returns to the step 320.
[0100] The telephone set on which the reader/writer RW is provided
may be replaced by a dispenser or an automatic vending machine.
[0101] The microcomputers 10 and 100 may be replaced by exclusive
control circuits composed of discrete analog circuits or discrete
digital circuits.
[0102] At least part of the combination of the microcomputer 10,
the memory 20, the modulation circuit 30, and the demodulation
circuit 50 may be formed by a single IC chip.
[0103] At least part of the combination of the memory 90, the
microcomputer 100, the power supply circuit 70, the modulation
circuit 110, and the demodulation circuit 80 may be formed by a
single IC chip.
* * * * *