JP2642426B2 - IC card - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to an IC (Integrated Circuit) card having a microcomputer, a memory, and a data transmission / reception unit built in an integrated circuit and used for various data processing and data transfer. About.

[Prior art] Conventionally, an IC card can recognize an ID code in a contactless manner.
It is used for systems and access control systems.
In an FA system, for example, an IC card that stores necessary codes is attached to the side of a work that moves on a rail, and the work is detected with the IC card and the necessary data is exchanged with the IC card. A main processing unit is installed. That is, the IC card stores the type of work and the like, and performs a processing operation by wirelessly communicating with the main processing device. In the entry / exit management system, the entry / exit person carries an IC card and communicates with the main processing device at the check location to monitor the entry / exit person.

For example, as shown by a broken line in FIG. 5, the IC card 2 is formed in a rectangular shape, attached to a work in the FA system, and carried by an entry / exit person in the entry / exit management system. The IC card 2 is provided with a loop antenna 20 for transmitting and receiving radio waves as a data transmission medium.

When the IC card 2 enters the reception area (monitoring area) of the radio wave radiated from the antenna 40 of the main processing device 4, the high frequency signal transmitted from the main processing device 4 can be received. When this high-frequency signal is applied to the data receiving unit 22 through the loop antenna 40, a required high-frequency signal is selected by a tuning circuit set to a tuning frequency equal to the carrier frequency _fr, and after detection, the data _DM is extracted. Then, it is taken into the data processing unit 24. The IC card 2 has a code setting section 26 for inputting necessary codes.
Is provided, for example, a person carrying an IC card 2,
Alternatively, an ID code of an object to which the IC card 2 is attached is set.

A microcomputer provided with a memory is installed in the data processing unit 24, and one character CR shown in FIG. 6, for example, is set as transmission data. This character CR consists of a start bit ST, a data bit D
For example, T, parity bit PT and stop bit SP are represented by 8 bits.

This character CR is used as a data output by the data transmission unit.
The signal is transmitted to the main processor 4 from the loop antenna 20 as a high-frequency signal after being modulated by the carrier _Cr .

Therefore, the IC card 2 transmits and receives necessary data to and from the main processing device 4 using radio waves as a medium. The FA system checks whether a work is passed or a predetermined process is performed. Management such as identification and passage of persons.

[Problems to be solved by the invention]

As shown in FIG. 5, the IC card 2 includes a data receiving unit 22 and a data transmitting unit 28 for transmitting and receiving data. 28 in the inactive state, and in the transmission mode, the data transmitting unit 28 is in the operating state and the data receiving unit is
The transmission and reception are switched so that 22 is inactive.

Conventionally, such transmission / reception switching is performed by software processing using a microcomputer provided in the data processing unit 24. For example, after data of one character CR is captured, the mode is switched to the transmission mode and the data is switched. A process for rejecting reception is performed, and necessary data is stored in the memory for storing and processing the transmission / reception switching program. Therefore, a necessary location must be set in the memory, and the burden on the memory is reduced. There was a disadvantage that it became larger.

Therefore, the present invention provides an IC that realizes switching between transmission and reception modes by using hardware to reduce a load on a memory.
The purpose is to provide a card.

[Means for solving the problem]

The IC card of the present invention wirelessly transmits and receives necessary data to and from the main processing device as illustrated in FIG.
An IC card, together with a data receiving unit that receives data transmitted by the main processing device, a data transmitting unit that transmits data to the main processing device is installed, and captures the data received by the data receiving unit. Data to be transmitted is generated, and a matrix circuit is constituted by a plurality of row lines and a plurality of column lines. Power is supplied to each connection point between the row lines and the column lines of the matrix circuit through a code setting line. A data processing unit having a code setting unit for setting a desired code by selectively disconnecting one or more of the code setting lines while grounding each connection point via a resistor. A code output unit for outputting the data to be transmitted from the data processing unit to the data transmission unit; and a code output unit built in the data processing unit, wherein the code output unit transmits the data transmission unit. An operation switching output unit for generating an operation switching output using the data when transmitting the data to the unit, and stopping the operation of the data receiving unit in response to the operation switching output generated by the operation switching output unit. An operation switching circuit for prohibiting input of received data from the data receiving unit to the data processing unit.

[Action]

With this configuration, in the transmission mode, the data processing unit outputs the operation switching output indicating the transmission mode, and the operation switching unit switches the data receiving unit to the non-operation state based on the operation switching output. As a result, the input of data from the data transmitting unit to the data processing unit is prevented.

Further, each IC card can easily set a desired code by cutting the code setting line, and is easily individualized.

〔Example〕

 FIG. 1 shows an embodiment of the IC card of the present invention.

The IC card 2 is provided with a loop antenna 20 so as to surround the periphery thereof. IC card 2 is main processor 4
When entering the reception area of the radio wave transmitted from the side, the high frequency signal transmitted by the radio wave from the antenna 40 of the main processing device 4 can be received. The high frequency signal is applied to the tuning circuit 221 through the loop antenna 20, the frequency of the tuning circuit 221 in the carrier C _r f _r equal tuning frequency f
Since _r is set, the high-frequency signal of the frequency f _r is selected. This high-frequency signal is applied to a detection circuit 222. In the detection circuit 222, a modulation signal representing data is detected by envelope detection.
Amplified at 3,224. The amplification operation of each amplifier 223, 224
An operation switching circuit 225 based on an output COM as an operation switching output indicating the reception mode and the transmission mode from the data processing unit 24.
The operation mode is switched in the reception mode, and the operation is selectively stopped in the transmission mode. As a result, the data processing unit 24 has a data input terminal in the reception mode.
Data D _M on the main processor 4 side from the amplifier 224 for DATA
Is taken in.

Then, as shown in FIG.
A microcomputer is installed, a central processing unit (CPU) 241 for performing data processing, a memory 242 for storing a program for performing data processing and necessary data, and an input / output unit (I / O for inputting and outputting data). ) 243 are linked by an address bus 244, a data bus 245 and a control bus 246. The input / output unit 243 of the data processing unit 24
In the transmission mode, a code output unit 247 that generates a required code output CODEOUT is provided.After inverting the output of the code output unit 247 through the inverter 248, the operation switching output unit 249 outputs the operation switching output. Output COM is generated. In the data processing unit 24, a crystal oscillation element
Timing is provided by the clock pulse generated by 25.

The IC card 2 is provided with a code setting unit 26 for inputting a necessary code to the data processing unit 24. The code setting unit 26 carries the IC card 2, for example. The ID code of the person who is wearing the product or the one to which the IC card 2 is attached is set, and the number of code patterns is 2 ¹⁶ ×
For the setting of 4, it is composed of a 4-digit, 16-column matrix circuit or the like. That is, four row lines 261 and 16 column lines 262 are combined to form a matrix configuration, and each connection point is set via a resistor 263 provided for each row line 261 and selectively disconnected. A power supply voltage V _DD is applied to a code setting line 264 through a resistor 265. Therefore, the code setting unit 26
Selectively select one or more of the code setting lines 264 as x
An arbitrary code is set by cutting as shown in (1), and the set specific code is added to the data processing unit 24. On the data processing unit 24 side, a transistor as a switching element is provided corresponding to the row line 261 and the column line 262, and a set potential generated by disconnection of the code setting line 264 is captured at a predetermined timing from the switching of the transistor. 4 × 2 ¹⁶ code patterns are obtained.

Then, in the data processing unit 24, when the data D _M taken in receive mode, it is determined whether or not from the main processor 4, is determined that the data from the main processor 4, with cord feeding command signal C _0, code output CODEOUT is outputted from the code output unit 247. The code transmission command signal C ₀ is a high (H) low (L) 2 level switching signal, and is applied to the carrier oscillator 281 as a drive start signal.

When the reception of the code representing a character CR is transmitted mode ends, cord feeding command signal C ₀ is shifted to H level, the carrier oscillator 281 starts its operation and generates the carrier C _r frequency fr . The carrier C _r is applied to a modulator 282, a pulse modulation is performed by the code output CODEOUT output as a modulation signal from the data processing unit 24. The modulation output M ₀ obtained from the modulator 282 is amplified by the power amplifier 283 and then applied to the loop antenna 20, and the modulation output M ₀ is transmitted as a radio wave to the main processing device 4 side.

In this transmission mode, the output COM as an operation switching output obtained by inverting the code output CODEOUT output from the code output unit 247 via the inverter 248 is applied from the operation switching output unit 249 to the operation switching circuit 225. in this case,
The operation switching output COM is connected to the LCD of the microcomputer.
A display output from the driver can be used. When the code output CODEOUT is at the H level, it is a switching signal corresponding to the code output CODEOUT which becomes the L level.

Therefore, in the transmission mode, the code output CO
The amplifiers 223 and 224 are operated by the operation switching output COM according to DEOUT.
The amplifying operation is stopped, and the load on the memory 242 can be reduced as compared with the conventional one in which a program and data for transmission / reception switching are stored in the memory 242 in the microcomputer. Power saving is achieved by stopping the operation.

Further, the IC card 2 is provided with a voltage detecting unit 291 for monitoring the consumption of the voltage of the power supply 290 including a built-in lithium battery and other abnormal states. The voltage detection unit 291 detects whether or not the voltage of the power supply 290 is normal, and outputs the detection output to the power supply reset unit 292. In the power reset unit 292, a reset signal R is generated by a detection output indicating a voltage abnormality from the voltage detection unit 291. This is a reset input unit RESET of the data processing unit 24.
Has been added to The reset signal R generated by the power reset unit 292 is a high-low two-level switching signal. For example, when the reset signal R becomes H-level, the power is reset and an abnormality of the power 290 is indicated. The abnormality of the power supply 290 is based on the data bit of one character CR as abnormal data.
The data is transmitted to the main processor 4 with the DT or the stop bit SP.

Next, FIG. 3 shows a specific circuit configuration example of the amplifiers 223 and 224 and the operation switching circuit 225 in the IC card shown in FIG.

Each of the amplifiers 223 and 224 includes an operational amplifier. The operation switching circuit 225 includes a voltage doubler rectifier circuit that forms a negative power supply for each of the amplifiers 223 and 224. In other words, between the power supply terminal V _SS and COM output terminal of the data processing unit 24, the diode D ₁ in which the COM output terminal side and the anode
And has a capacitor C ₁ is connected in series, the series circuit of the diode D ₂ and capacitor C ₂ which with respect to the diode D ₁ and the diode D ₁ side to the cathode are connected in parallel. Then, from the connection point between the diode D ₂ and the capacitor C ₂ , the negative voltage −V _DD or the positive voltage + V
_DD is obtained. Therefore, the amplifiers 223 and 224 are provided with the diode D together with the positive voltage + V _DD obtained from the data processing unit 24.
_A negative voltage −V _DD or a positive voltage + V _DD is selectively applied through a voltage doubler rectifier circuit composed of ₁ , D ₂ and capacitors C ₁ and C ₂ .

According to such a configuration, in the reception mode, the code output CODEOUT becomes L level and the COM output becomes H level as shown in FIGS. 4A and 4B. ₁ is charged, and a negative voltage −V _DD is generated in the operation switching circuit 225 through the charging of the capacitor C ₁ , and the amplifiers 223 and 224 perform an amplifying operation for data reception by the negative voltage −V _DD .

In the transmission mode, as shown in FIGS. 4A and 4B, the code output CODEOUT becomes H level and the COM output becomes L level.
The charging voltage of ₁ is added, the capacitor C2 is charged with a voltage twice as _high as the COM output, and the operation switching circuit 225 has a positive voltage of + V
_DD occurs, and the amplification operation of the amplifiers 223 and 224 is stopped by the positive voltage + V _DD . In this case, the voltages + V _DD , −V _SS , and −V _DD selectively obtained by the voltage doubler rectifier circuit theoretically generate a voltage of 2V _DD.
The switching of the 24 amplifying operations is facilitated, and a low-voltage operation operational amplifier for switching the operations is not required.

In the embodiment, the operation of the data receiving unit 22 is stopped only in the H level section during the code output. However, the code transmission command signal C for controlling the operation of the carrier oscillator 281 is provided.
The operation of the data receiving unit 22 may be completely stopped in the transmission mode using ₀ .

Further, in the embodiment, when performing modulation of the carrier _Cr by data, pulse modulation has been described as an example, but the present invention can use various modulation schemes such as ASK modulation, FSK modulation, and PSK modulation. .

〔The invention's effect〕

As described above, according to the present invention, the following effects can be obtained.

(A) A desired code can be easily set by cutting the code setting line, and each IC card can be easily individualized.

(B) Since the operation of the data receiving unit is stopped by the operation switching circuit by the operation switching output, the load on the memory in the data processing unit can be reduced, and the power consumption can be reduced by stopping the operation of the data receiving unit. The consumption of the built-in battery can be suppressed.

[Brief description of the drawings]

FIG. 1 is a block diagram showing an embodiment of the IC card of the present invention, FIG. 2 is a block diagram showing a configuration of a data processing unit in the IC card shown in FIG. 1, and FIG. 3 is a diagram shown in FIG.
FIG. 4 is a circuit diagram showing an operation switching unit in the data receiving unit of the IC card, FIG. 4 is a diagram showing the operation of the operation switching unit shown in FIG. 2, FIG. 5 is a block diagram showing the configuration of a conventional IC card,
FIG. 6 is a diagram showing one character of transmission data. 2 IC card 4 Main processing unit 22 Data receiving unit 28 Data transmitting unit 225 Operation switching circuit 24 Data processing unit 247 Code output unit 249 Operation switching output unit 261 … Row line 262 …… column line 264 …… code setting line

Claims (1)

(57) [Claims] An IC card for wirelessly transmitting and receiving necessary data to and from a main processing device, wherein the IC card transmits data to the main processing device together with a data receiving unit that receives data transmitted by the main processing device. A data transmitting unit for transmitting is installed, the data received by the data receiving unit is fetched, data to be transmitted is generated, and
A matrix circuit is configured with a plurality of row lines and a plurality of column lines, and a power supply is connected to each connection point between the row line and the column line of the matrix circuit via a code setting line, and the connection points are connected to each other. Ground through a resistor and connect one of the code setting lines.
Or, a data processing unit having a code setting unit for setting a desired code by selectively disconnecting two or more, and a code for outputting the data to be transmitted from the data processing unit to the data transmission unit An output unit, which is incorporated in the data processing unit and, when the code output unit sends the data to the data transmission unit, generates an operation switching output using the data; An operation switching circuit that stops the operation of the data receiving unit in response to the operation switching output generated by the output unit, and inhibits input of received data from the data receiving unit to the data processing unit. IC card.