JPH01280890A - Ic card - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION <Industrial Application Field> The present invention is applied to an IC card that is inserted into a transmitter/receiver, which is an external device, and exchanges information with the transmitter/receiver.

<Prior Art> An IC card containing a small arithmetic device, a memory, etc. is put to use by exchanging information with a transmitting/receiving device such as a computer.

The operation of a conventional IC card will be explained based on FIGS. 9 and 10.

First, in FIG. 9, which shows the operation sequence of an IC card, when the IC card is inserted into a transceiver and the microcomputer unit (MPU) inside the IC card receives a command from the transceiver, this command is checked. executes command processing and outputs the results to the transceiver. In addition, in this operation, if there is an error in the communication from the transceiver or if there is an error in the command, an error message is output to the transceiver.

The MPU of the IC card is performed according to the cycle shown in FIG. That is, the IC card is inserted into the transceiver, the transceiver supplies the power supply voltage Vcc and the clock signal CLK to the MPU of the IC power mode, and the transceiver also sends a reset signal R5T (over bar) to the MPU manually. Then, the MPU performs a reset routine (AO) such as initialization, and sends an answer signal ANSWERTo RESE informing the transceiver that transmission is possible.
t (A1). Then, the MPU waits for input of a command signal (serial signal 5IO that includes data as well as command) from the transceiver (A2), and if the command signal is input manually (A3), executes command processing (A
4) Output the result to the transceiver (A5). When such a series of operations is completed, the MPU waits for the next command signal to be manually input from the transceiver (A2), and when the command signal is input (A3), repeats the same process as above.

<Problem to be solved by the invention> Here, if the transceiver into which an IC card is inserted is made portable, its use as an IC card system will expand, so it is possible to make the transceiver equipped with a built-in power battery to make it portable. - It is strongly desired that the

In order to realize such a system, it is necessary to extend the life of the power supply battery built into the transceiver, and it is necessary to suppress the consumption of power supplied from the transceiver to the IC card as much as possible. One possible solution to this problem is to increase the capacity of the battery, but there is a limit to increasing the battery capacity due to constraints on the installation space of the battery, the need to reduce the weight of the transmitter/receiver, and so on. Another possibility is to change the device built into the IC card to a low-power-consumption CMOS, but this poses a major problem in terms of IC card development costs, such as requiring a new design for the devices.

The present invention has been made in view of the above-mentioned conventional circumstances, and it is an object of the present invention to rationally achieve low power consumption of an IC card without the above-mentioned problems.

Means for Solving the Problems> An IC card of the present invention that achieves low power consumption is an IC card equipped with a small arithmetic unit having an information processing mode and a low power consumption mode, in which the small arithmetic unit is activated. low power consumption mode transition means for transitioning the small arithmetic unit to a low power consumption mode after the small arithmetic operation has been performed; and an information processing mode for transitioning the small arithmetic unit from the low power consumption mode to an information processing mode in response to an interrupt signal from an external transceiver. The present invention is characterized by comprising a transition means and a low power consumption mode return means for causing the small-sized arithmetic device to transition to the low power consumption mode again after performing information processing.

Function> The small arithmetic unit (CPU) built into the IC card of the present invention
, MPU) automatically transitions to the low power consumption mode after being activated by the low power consumption mode transition means, and changes from the low power consumption mode to information processing by the information processing mode transition means when an interrupt signal from the transceiver is input. mode and executes information processing based on commands from the transceiver. Then, after the small arithmetic device outputs the results of the information processing to the transmitter/receiver, the small-sized arithmetic device transits to the low power consumption mode again by the low power consumption mode return means. That is, while waiting for a command signal from the transmitter/receiver to be input manually, the small arithmetic unit of the IC card is in a state of transitioning to a low power consumption mode, reducing power consumption during this time.

<Example> The IC card of the present invention will be specifically described based on an example.

First, the configuration of an IC card according to an embodiment of the present invention will be explained in the first section.
This will be explained based on the diagram.

The IC card 1 has a built-in EEPROM 3 that can be written and read as a memory together with an MPU 2 which is an ultra-small arithmetic unit, and the MPU 2 and the EEPROM 3 are connected by a multi-bit address signal line An, a data signal line D8, and a control signal line CTRL. has been done.

The MPU2 in this embodiment is HD6 manufactured by Hitachi.
The 301 series is used.

The transceiver 5 into which the IC card 1 is inserted exchanges data with each other.
It has an interface 6 and a personal computer 7 connected via an address bus. The transmitter/receiver 5 is a portable and portable device that integrates an interface 6 and a personal computer 7, and has a built-in battery (not shown) as its power source.

In use, the IC card 1 is inserted into the interface 6, the power terminal Vcc and the ground terminal GND of the interface 6 are connected to the MPU 2 and the memory 3, respectively, and the power supply voltage is applied to the MPU 2 and the memory 3 from the transceiver S side. supply.

In addition, the clock signal output terminal CL of the interface 6
K, Reset signal output terminal RST (over bar)
are connected to the MPU2, and the MP
A clock signal and a reset signal are input to U2. Also, the information signal input/output terminal SIO of the interface 6 is M
It is connected to the output terminal TX, input terminal RX, and interrupt signal input terminal IRQ (over bar) of the PU 2, and information is exchanged between the transceiver 5 and the IC card 1. still,
The IRQ (over bar) terminal of the MPU 2 is connected to the RDY/BUSY (over bar) terminal of the memory 3, and IRQ interrupts to the MPU 2 are prohibited during writing to the memory 3, as described later.

The operation of the IC card 1 having the above structure will be explained with reference to the flowcharts shown in FIGS. 2 to 6.

First, as shown in Figure 2, which represents the main routine, the IC
When the card 1 is inserted into the transceiver 5 and the power supply voltage Vcc is supplied from the transceiver 5, as well as the clock signal CLK and the reset signal RST (over bar) are input, the MPU 2 performs a hard reset routine such as initialization. (step S1), and sends an answer signal ANSWERT to inform that the command signal can be transmitted to the transceiver 5.
ORESET is output (step S2).

Next, the MPU 2 executes a 5LEEP MODE transition routine (step S3), and transitions to the sleep mode, which is the low power consumption mode in this embodiment. 5LEE
In the P MODE transition routine, as shown in FIG. 3, the IRQ (over bar) terminal of MPU2 is activated to enable interrupts by inputting an IRQ interrupt signal (step 521), and the information processing circuit of MPU2 is stopped. The power consumption is extremely low (approximately 1/1 of normal operation).
6) Command transition to sleeve mode (step 52)
2). Steps S3 and S2 executed by these MPU2
1, S22 constitutes a low power consumption mode transition means for transitioning the MPU 2 to a low power consumption mode after startup.

In the state where the MPU 2 has transitioned to the sleeve mode by the transition command to the sleeve mode, the MPU 2 determines whether or not an IRQ interrupt signal has been input from the transceiver 5 to the IRQ (over bar) terminal (step S4).
ACTIVE M when an interrupt signal is input
Step S5) to execute the ODE transition routine, the MPU
A transition is made to an active mode (information processing mode) in which the No. 2 information processing circuit is activated. ACTIVE MODE
In the transition routine, as shown in FIG. 4, in response to the IRQ interrupt signal, the IRQ (over bar) terminal of the MPU 2 is masked to make it impossible to be interrupted by the input of the IRQ interrupt signal (step 531), and the stack pointer is A specified value is set in SP (step 532), and the address of the command input routine shown in FIG. 5 is set in the program counter PC (step 533). These MP
Steps S4, S5, S31, S32 executed in U2
, S33 performs M based on the interrupt signal from the transceiver 5.
It constitutes an information processing mode transition means for transitioning the PU2 to an information processing mode.

In the state in which the MPU 2 has transitioned to the information processing mode in step S5, the MPU 2 executes processing based on a command signal (a byte-based serial signal that includes data as well as a command) input from the SIO of the interface 6 (step S6).

5LEEP 'MODE after finishing this information processing
A transition routine is executed to transition to the sleeve mode again (step S7). That is, as shown in FIG. 7, after receiving a command (A3), processing it (A4), and outputting the processing result (A5), until the next command is input (interface 6 and computer 7), the MPU 2 transitions to and maintains a sleep mode with low power consumption. Step S7 executed by the MPU 2 constitutes a low power consumption mode return means for returning the MPU 2 to the low power consumption mode again after completing the information processing.

In the command processing in step S6 above, FIGS.
The process shown in the figure is executed. That is, when a command signal is input (step 541), it checks whether there is an error in this input communication (step 542), further checks the command (steps S43 and 44), and executes processing according to the command ( Step 545) Output the result to the transceiver 5 (Step 546). Note that if there is an error in the input communication or command, error processing is executed (step 547) and an error message is output.

Further, when writing processing to the memory 3 is executed in the above command processing (step 545), a transition to sleeve mode is performed as shown in FIGS. 6 and 8. That is, the MPU 2 sends a control signal to the memory 3 to instruct data writing and supplies an address and data (step 551). Then, the 5LEEP MODE transition routine shown in FIG. 3 is executed (step 552), and the MPU 2 transitions to the sleeve mode. While the memory 3 write process is being executed, the RDY/BUSY (over bar) of memory 3 is “
It becomes L” level, which is inverted by inverter 8 and becomes M
Supplied as “H” level to IRQ of PU2, IRQ
Keeps interrupts disabled. Like this M
When PU2 is in sleeve mode, memory 3
When writing to memory 3 is completed, RDY/BUS of memory 3 is
Y (overboard bar) goes to the "H" level, which is inverted by the inverter 8 and supplied to the IRQ of the MPU 2 as the "L" level, causing an interrupt to the IRQ (step 553), as shown in FIG. ACTIME M.O.
The DE transition routine is executed to transition to active mode (step 554). That is, while data is being written to the memory 3, the MPU 2 is kept in a sleep mode with low power consumption.

In addition, as a low power consumption mode, the HD630 of the above embodiment
Although the sleeve mode is used in the 1-series semiconductor device, various other settings such as a no-operation mode can be set depending on the type of semiconductor device constituting the small-sized arithmetic device.

Furthermore, if CMO3 is used as the semiconductor device, further reduction in power consumption can be achieved.

Effects> According to the present invention, while waiting for a command signal from the transmitter/receiver to be input manually, that is, during the time that occupies a considerable portion of the time after the IC card is activated, the small arithmetic unit of the IC card enters the low power consumption mode. Since the state is changed, the power consumption of the IC card can be significantly reduced. Such reduction in power consumption can be achieved at low cost without changing the IC card device. As a result of being able to significantly reduce the power consumption of the IC card in this manner, the transmitter/receiver can have a built-in power supply battery to make the transmitter/receiver portable, and the applications of the IC card system can be expanded.

Further, the application of the present invention is not limited to a transceiver that has a built-in power battery, but can also be applied to a case where an IC card has a built-in power battery. This has the effect of extending the life of the IC card by reducing power consumption. Furthermore, the present invention can be applied to an IC card that does not have a built-in battery and does not use a battery as a power source for a transmitter/receiver.
This has the effect that the heat generated by the semiconductor device built into the C card can be reduced and the durability of the IC card can be improved.

[Brief explanation of the drawing]

Fig. 1 is a block diagram of an IC card system according to an embodiment of the present invention, Fig. 2 is a flowchart of a main routine showing the operation of an IC card according to an embodiment of the present invention, and Fig. 3 is a flowchart of the main routine to the 5LEEP MODE. A Fuco chart showing the transition routine of , Figure 4 shows its ACTIVE MODE
5 is a flowchart showing the command input routine, FIG. 6 is a flowchart showing the memory write routine, and FIG. 7 is a time chart explaining the mode state of the IC card in response to a command signal. FIG. 8 is a time chart for explaining the operation during memory writing, FIG. 9 is a time chart for explaining the operation of a conventional IC card, and FIG. 10 is a time chart for explaining the operation of the MPU. ] is an IC card, 2 is a small processing unit (MPU), 5 is a transceiver, 6 is an interface, and 7 is a computer. Patent Applicant Toppan Printing Co., Ltd. Agent Patent Attorney Kiyoshi Kuwai - Figure 1 - 111 - Figure M2 Figure 3 Figure 4 Figure 5 Figure 6

Claims (1)

[Claims] In an IC card equipped with a small arithmetic device having an information processing mode and a low power consumption mode, a low power consumption mode transition means for transitioning the small arithmetic device to a low power consumption mode after the small arithmetic device is activated; information processing mode transition means for transitioning the small arithmetic unit from a low power consumption mode to an information processing mode in response to an interrupt signal from an external transceiver; and for transitioning the small arithmetic unit to the low power consumption mode again after performing information processing; An IC card characterized by comprising means for returning to a low power consumption mode.