JP2919225B2 - Method for detecting intentional power interruption and anti-theft device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method of detecting intentional power-off in a device equipped with a microcomputer electronic circuit and detecting an intentional power-off and generating an alarm signal. The present invention relates to a vehicle anti-theft device that can be installed in an automobile controlled by a circuit.

[0002]

2. Description of the Related Art In an automobile, a motorcycle, a door of a house, a safe, an OA device, etc., a specific ID code is previously registered in a microcomputer circuit, and an ID code of an entry medium such as an operated key or a magnetic card is registered. A system has been put into practical use in which the device is read, and when the registered ID code is matched, the locked state of the device is released, and only a specific operator is allowed to perform the operation.

For example, in an example of a keyless entry system in an automobile, a key for unlocking a door or a remote control device is assigned a 4-word 64-bit ID code.

When an operator operates a key or a remote controller, a dedicated receiver of the vehicle detects the ID code and compares the ID code with a plurality of ID codes registered in a microcomputer circuit mounted on the vehicle. Only when the vehicle speed is equal to, the interlock related to the handle lock and the engine control is released together with the door lock, and the normal driving operation becomes possible.

[0005] In an example of a keyless entry system for an automobile, an EEPROM (Electronic Ela- tive Memory) is provided so that a registered ID code is not lost when a battery goes down or a momentary power failure of a microcomputer circuit occurs.
The ID code is backed up in a sable programmable read only memory (LED) element.

Whenever the ID code stored in the microcomputer circuit is lost, the EEPROM is accessed and read each time, and when registering a new ID code, the microcomputer circuit is used. From the side, writing is performed to the data bits of 4 words and 64 bits of the EEPROM element.

[0007] In the example of the keyless entry system in a car, further, in order to illegally drive the car,
An anti-theft device is mounted to cope with a method of intentionally shutting down the battery and resetting the microcomputer circuit.

FIG. 6 is an explanatory view of a conventional anti-theft device. Here, the presence or absence of the electric charge charged in the capacitor is detected, and the intentional interruption of the battery is detected.

In FIG. 6, an ECU (Electronic Control)
ol Unit) 60 is various sensors mounted on the car,
A computing device that controls electronic circuits and electrical equipment in an integrated manner. The ECU 60 instructs, for example, the operation / stop of the wiper and automatically adjusts the operation speed according to the output of the rain sensor.

[0010] The ECU 60 is in charge of controlling the unlocking of the door with respect to the keyless entry function, and compares the ID code of the key read by the receiver 62 with a plurality of ID codes registered in the ECU 60 in advance. If any of them match, the door lock mechanism 63 of the automobile
To allow the ride. At the same time, the interlock relating to the steering wheel and the engine control is released, so that a normal driving operation by the occupant is enabled.

The ECU 60 also controls the charging / discharging of the capacitor 61 with respect to the anti-theft function, identifies the presence or absence of the charge charged in the capacitor 61, and detects intentional battery shutdown.

That is, when a door lock command is input, the ECU 60 lowers the arm terminal to the L level, turns on the transistor 64C, and charges the capacitor 61 with the power supply V _CC through the diode 64D.

After that, when a command for unlocking the door is input from the receiver 62, the ECU 60 drops the disarm terminal to L level and sets the transistors 64A, 64A.
B is turned on, and the electric charge charged in the capacitor 61 is discharged to the ground through the transistor 64B.

However, when a power supply is connected to the ECU 60, a normal power-on reset operation is performed,
Capacitor 61 from detection terminal through diode 64D
Is detected, and when the charging voltage of the capacitor 61 is at the H level, an alarm output command is issued to the alarm circuit 65. The alarm circuit 65 outputs a loud alarm through the speaker 66.

That is, the reconnection of the battery and the ECU 60 in a state where the "discharge of the capacitor 61 due to a normal entry operation" is omitted is determined to be an abnormal intrusion into the vehicle and intentional power-off, and the surrounding goodwill is notified through an alarm. The attention of the car and the intruder.

[0016]

The conventional anti-theft device is composed of a dedicated electronic circuit including a plurality of transistors, resistors, capacitors, and the like. Therefore, the electronic device includes wiring of the electronic circuit and connection with the microcomputer circuit. There has been a problem that the overall configuration of the control device has been increased in size, and it has been difficult to reduce assembly and installation costs.

It is desirable that the anti-theft device is preferably unsealed integrally with an arithmetic element for executing a program. However, the conventional anti-theft device using a combination of individual components is difficult to dispose on a printed circuit board on which an arithmetic element is mounted from the viewpoint of its size. It was necessary to extend the dedicated wiring.

Therefore, it is necessary to specially increase the size of the case of the arithmetic unit equipped with the anti-theft device, and the compatibility with the case of the arithmetic unit not equipped with the anti-theft device is lost. The mounting part also had to be specially redesigned.

In the anti-theft device shown in FIG. 6, the electric charge charged in the capacitor 61 is gradually reduced by the leakage current, and after a period of one week or more, the key and the ECU 60 do not go through the normal key entry. There was a problem that reconnection could not be identified as abnormal.

Attempts have been made to increase the capacity of the capacitor 61. However, a large-capacity capacitor with little leakage becomes expensive and large, causing a new mounting problem with respect to the arithmetic unit, and also requires a large capacity. The power drawn from the battery for charging has also reached non-negligible levels.

Further, when the anti-theft device is not mounted and when the housing of the arithmetic unit is shared and the capacitor is arranged outside the housing, an intruder of the vehicle cuts the wiring of the capacitor and does not generate an alarm output. Inability to cope with tricks.

SUMMARY OF THE INVENTION It is an object of the present invention to provide a deliberate power-off detection method and an anti-theft device which can be equipped with a small size, light weight and low cost, and do not need to erroneously detect an abnormal power-off even after a long period of time. And

[0023]

According to a first aspect of the present invention, there is provided a method for intentionally detecting a power cut-off, wherein a data address used as one or more data bits in an EEPROM is changed every time a normal lock operation of a device is detected. After registering the changed data address in another one or more data bits of the EEPROM, predetermined data is written to the registered data address, and when a normal unlock operation is detected, the data is written to the data bit. When the power of the device is connected, the data address registered in the another one or more data bits is read, and the one or more data addresses are read based on the data address. In this method, a data bit is read, and a warning signal is generated when the read data is identified as the predetermined data.

A method for detecting intentional power cutoff according to claim 2 is as follows.
2. The intentional power-off detection method according to claim 1, wherein when the power of the device is connected, data is read from a plurality of data bits of the EEPROM, and the read data is converted to the predetermined data. Even if they do not match, if the match is identified by at least a majority of data bits, the read data is identified as the predetermined data.

According to a third aspect of the present invention, there is provided an EEPROM (1) for registering a unique code for unlocking a door of a vehicle.
(1) a control means (12) for identifying a unique code operated on the vehicle and unlocking the door lock of the vehicle when the unique code matches the unique code registered in the EEPROM (11). Switching means for changing a data address used as one or more data bits in the EEPROM (11) each time a door lock operation is detected in the vehicle. Registering means for registering the data address of the one or more data bits with another one or more data bits of the EEPROM; writing means (13) for writing predetermined data to the registered data address; A new door lock release operation, and replaces the data written in the one or more data bits with another predetermined data. When the power is connected to the removing means (14) and the control means (12), the data address registered in the another one or more data bits is read, and the one or more data bits are read based on the data address. Selecting means for reading the above data bits; abnormality detecting means (15) for generating a warning signal when the data read by the selecting means is identified as predetermined data of the door lock operation; It has.

According to a fourth aspect of the present invention, in the anti-theft device of the third aspect, when the abnormality detecting means is connected to a power supply to the control means, data of a plurality of data bits of the EEPROM is read out. Even if the read data does not match the predetermined data, if at least a majority of the data bits indicate a match, majority means for identifying the read data as the predetermined data .

[0027]

According to the first aspect of the present invention, one or more data bits of an EEPROM are used in place of the capacitor, and the stored contents of the data bits are read out and identified instead of detecting the remaining capacity. A normal unlock operation and an abnormal unlock operation of the device are identified.

According to this method, in a car, a motorcycle, a door of a house, a safe, an OA device, etc., an operation entry is made to the device through an abnormal unlocking operation, and various interlocks set in the device are released. When the power supply is temporarily shut down, the abnormal unlock operation is identified at the timing of the power supply reconnection, and an alarm signal is generated.

This alarm signal is output by voice or illumination, an alarm is reported to a device management center, a new interlock is automatically set to disable normal operation of the device, and a partial self-destruction function of the device is provided. It can be used for triggers and so on.

When the operator performs a normal lock operation on the device, the device identifies the normal lock operation and performs EE.
Predetermined data indicating the locked state is written to at least one data bit of the corresponding address of the PROM.

Thereafter, when the operator performs a normal unlocking operation on the device using a key, a magnetic card, a remote controller, or the like, the device side identifies the normal unlocking operation and applies the corresponding unlocking operation to the EEPROM. The predetermined data indicating the locked state written at the address is erased.

Then, when the power is reconnected to the device placed in the cutoff state, the data stored in the corresponding address of the EEPROM is read, and when the data is the predetermined data indicating the locked state, the normal state is determined. It is determined that the intentional power-off without the necessity of the unlock operation has been performed, and an alarm signal is generated.

According to a second aspect of the present invention, there is provided an anti-theft device including an arithmetic unit for comparing a unique code input in response to a door lock release operation performed on a vehicle with a registered unique code, and Even if the power supply of the arithmetic unit is cut off, the registered unique code is stored in a nonvolatile state in the EEPROM 11 so that the door lock release operation when the power supply is turned on again does not hinder the operation. Is done.

That is, using the data bits of the vacant address of the EEPROM 11 provided for the purpose of backing up the unique code, the presence or absence of a normal door unlock operation in a state before the power is turned off is stored.
An alarm signal is generated when the power is reconnected without going through a normal door unlocking operation.

That is, the existing arrangement of the arithmetic unit for identifying the unique code and the EEPROM 11 is used as it is,
The normal door lock operation and the normal door lock release operation are registered in the same procedure as the registration of the unique code. Also,
When the power supply is reconnected to the arithmetic unit, the registered data relating to the door lock is read out in the same procedure as that for reading out the registered unique code.

The program stored in the arithmetic unit for reading and identifying the registered unique data relating to the door lock is preferably formed integrally with an arithmetic program for reading and identifying the unique code and other arithmetic programs. Is done.

The EEPROM 11 stores, in addition to the unique code registered in advance for unlocking the vehicle door, at least the last of the proper door lock operation and the door unlock operation performed on the vehicle in a nonvolatile manner. To memorize.

The control means 12 includes a program for comparing a unique code input through a key operation, a numeric keyboard, a magnetic card, a remote controller or the like with a previously registered unique code. When the power supply is reconnected, the EEPRO
The program may include a program that accesses M11 to read out the registered unique code and stores it in the RAM in the arithmetic device.

When a normal door lock operation is input to the vehicle, the writing means 13 writes data to the EEPROM 1.
Specific data indicating a door lock operation is written in the corresponding address of No. 1. When the normal door unlocking operation is input to the vehicle, the erasing means 14 performs EEP.
The specific data indicating the door lock operation in the ROM 11 is replaced with another specific data indicating the door unlock operation.

Here, one of the two data meaning the door lock operation and the door lock release operation, respectively, is 1,
The other data may be all zeros, and the previous data may be replaced by a format that deletes the previous data. This is because if the data is simple data, the data content of the door lock operation and the door lock release operation can be immediately identified without separately storing the data in the ROM or the like.

When the power supply is connected to the control means 12, the abnormality detection means 15 reads data indicating the distinction between the door lock operation and the door lock release in the EEPROM 11, and identifies the read data. Then, when it is determined that the data is the door lock operation data, a warning signal is output.

The identification of the read data includes (1) perfect match with the data of the door lock operation, (2) match of majority bit using plural bit data, that is, majority decision, and (3) data of the door lock operation. (4) The data of the door lock operation is stored in three or more addresses in parallel, and each bit of a plurality of data read from these addresses is compared. This is performed by a method of extracting bit data that matches two or more bits and reproducing the write data. According to the methods (2) to (4), it is possible to prevent an erroneous identification due to data corruption during storage in the EEPROM.

Further, in the method for detecting intentional power-off according to the first aspect and the anti-theft device according to the third aspect, the EEPRO
Normal lock / unlock operation of the device in M
The address for storing the data of the vehicle door lock operation / door unlock operation is changed for each normal lock operation or door lock operation, and the changed address is also EEPRO.
M. If writing and erasing are repeated a number of times at a specific address of the EEPROM, the memory cell at this address will be degraded and normal writing cannot be performed, or the data being stored will be lost. This is because garbage is likely to occur.

Accordingly, when the power supply is reconnected to the control means, the data address stored in the EEPROM by the registration means is first read from the EEPROM, and subsequently the data content of this data address is read.

According to the intentional power cut-off detection method of the second aspect and the anti-theft device of the fourth aspect, the normal lock operation / unlock operation or the door lock operation / door unlock operation in the data read from the EEPROM is performed. The distinction is identified through a so-called majority operation. That is, in the EEPROM, the distinction between the normal lock operation / unlock operation or the door lock operation / door unlock operation is stored as data of 3 bits or more, and the normal lock operation is performed by more than half of the read data. Alternatively, when a match with the data of the door lock operation is identified, an abnormality is determined.

[0046]

FIG. 2 is an explanatory view of the configuration of the anti-theft device of the embodiment, and FIG. 3 is a flowchart of the anti-theft device of the embodiment. Here, the circuit configuration of the computing device of the vehicle that allows keyless entry is also used as the anti-theft device as it is, and intentional power-off is detected by a slight change in the program stored in the computing device.

In FIG. 2, an ECU 20 that controls the electric equipment of the vehicle in a comprehensive manner and performs various arithmetic processes according to input states of various sensors includes an arithmetic unit 21 and an EEPROM 2.
3, including a random access memory (RAM 25), a read only memory (ROM) not shown, and the like.

Here, the arithmetic unit 21 and the EEPROM 23
In addition, since the serial input / output type is selected,
There is no need for a shift register for input / output data conversion between them.

The arithmetic unit 21 executes various arithmetic operations according to the external input, and stores the EEPROM 23,
It controls the RAM 25 and the like. The EEPROM 23 has a capacity of 1 kbit and stores a maximum of 6 bits of data of 16 bits per word.
Up to four words can be stored in a nonvolatile manner.

In the EEPROM 23, the operation unit 21
Select one of the 64 types of addresses through the designated terminal,
If a write command is sent from the command terminal in a state where serial transmission of 16-bit data has been completed from the write / read terminal, the 16-bit data is registered at the designated address.
When a read command is sent from the command terminal, 16-bit data at the specified address is read serially.

The EEPROM 23 uses a total of 16 words, 4 words for each unique code, in order to register four types of unique codes for keyless entry. For the storage operation.

The RAM 25 stores four types of unique codes registered in the EEPROM 23. When the keyless entry operation is performed, the registered unique codes are stored in the arithmetic unit 21.
To send to. However, when the power supply of the ECU is cut off, the stored contents are lost, so when the power supply is reconnected to the ECU,
The four kinds of unique codes read from the EEPROM 23 are stored again through the arithmetic unit 21.

The receiver 26 includes a key hole 26K disposed on the door of the automobile or a door lock / door unlock command by a remote controller (not shown).
The unique code obtained by identifying the operated key or the remote control signal is input to the arithmetic unit 21 of the ECU 20.

The arithmetic unit 21 discriminates the door lock / door unlock command only when the unique code sent from the receiver 26 matches any of the four unique codes read from the RAM 25. , The door lock mechanism 28 is controlled in accordance with the instruction to realize door lock / door lock release as instructed.

On the other hand, with respect to the intentional power-off detection function, the arithmetic unit 21 sets the EE every time the door is locked.
Sixteen 0s are written into one word 16 bits at a specific address of the PROM 23. Each time normal door unlocking is executed through the receiver 26, this one word 16 bits data is written into 16 1s. Rewrite (delete).

When the battery is reconnected to the ECU 20, the 16-bit data of one word is read from this specific address of the EEPROM 23, and when the data content is identified as 16 zeros, a normal door is read. It is determined that the power supply is intentionally shut off without performing the lock release operation, and an alarm signal is output to the alarm circuit 27.

The specific address is stored in a ROM (not shown) of the ECU 20, and is read through a power-on reset program when the power is reconnected.
The alarm circuit 27 outputs a loud sound alarm through the speaker 27S.

The data bits of the EEPROM 23 are 10 bits.
Ten thousand rewrites are guaranteed, and it is possible to withstand 73,000 rewrites in 10 years, 365 days a year, assuming 20 door lock / door unlock operations a day.

In FIG. 3, when the power supply is reconnected to the ECU shown in FIG.
Operates, and the operation program is read from the ROM.
Subsequently, in the EEPROM data input 32, data indicating the distinction between the door lock and the door unlock in the last state before the power is turned off is read from the EEPROM. Further, the identification unit 33 identifies whether the read data is 16 zeros indicating a door lock, and if the data is 16 zeros, an alarm (alarm signal) is output.

The program below the identification unit 33 is a part which is repeated in a normal state in which the power supply is connected to the ECU.
During various operation programs executed by the CU, a step 34 of detecting a door lock operation and writing 16 0s to the EEPROM, and detecting a normal door unlock operation to change 16 16s of the EEPROM to 16 bits. A step 35 for rewriting to one is inserted.

FIG. 4 is a flowchart of the anti-theft device according to another embodiment. Here, only a part of the program executed by the arithmetic unit is changed using the same circuit configuration as that of FIG. 2, and the address to which the door lock data is written is changed every time the door lock operation is performed.

In FIG. 4, the selection unit 41 first reads from the EEPROM the address of the EEPROM in which data indicating the distinction between the door lock and the door unlock is written before the power is turned off. Address is n +
One of one type of address. Next, the data at the read address is accessed, and data indicating the distinction between door lock / door unlock is read.

As in the case of the embodiment of FIG. 3, the read data is identified as a door lock state by matching 16 0s, that is, all digits.

In the following portion which is repeated in a normal state in which the power supply is connected to the ECU, the switching portion 4 detects the door lock operation and writes 16 0s to the EEPROM.
2 has been replaced.

In the switching section 42, the next (+)
The address 1) is selected, and the newly selected address is written to a specific address in the EEPROM. This specific address is stored in the ROM of the ECU,
It is read into the arithmetic unit through a power-on reset program when the power supply is reconnected to the ECU.

Subsequently, 16 0s are written to the newly selected address. When the newly selected address reaches n + 1, the address is returned to 0, and the address 0 which was written n + 1 times before is read.
Then, this new writing is executed.

On the other hand, when the door is normally unlocked, the eraser 43 replaces the 16 0s written at the time of the previous door lock with the 16 1s.

In the anti-theft device of another embodiment, the number of times of writing / erasing in one memory cell used is shown in FIG.
Can be greatly reduced as compared with the embodiment, the reliability of the EEPROM can be maintained high, and erroneous identification due to garbled data during storage can be prevented.

FIG. 5 is a part of a flow chart of the anti-theft device of still another embodiment. In still another embodiment, the identification unit 3 shown in FIG.
3 is replaced as shown in FIG. Here, 1
The door lock state is not identified by a match of six 0s, but is determined by a majority decision, that is, when 1 is detected by more than a majority of 16 bits, the door lock state is determined to be normal and the number of 1s is determined. Is smaller than the majority, it is determined that the door is locked.

In FIG. 5, one word 1 read from the EEPROM by the EEPROM data input unit 32 in FIG.
The 6-bit data is sequentially extracted one bit at a time by the data shift unit 51, and 1 or 0 is identified by one bit each time. Each time 1 is identified, the countdown of the CF count is executed, and before the shift count of 16 initially set ends and a borrow (borrow) is output, the CF set of 8 initially set is output.
When the counting is completed, it is determined that there are 9 or more 1s in 16 bits.

That is, the read 16 bits of one word have undergone a normal door lock release operation at the last stage before the power is turned off, and the 16 0s written by the door lock operation before that time. Is determined to have been deleted through a normal door lock release operation. Therefore, no alarm is output.

On the other hand, if the initially set 16 shift counts are completed before the initially set CF count of 8 is completed and a borrow (borrow) is output,
It is determined that there are 9 or more 0s in 16 bits.

That is, the read 16 bits of one word have not passed through the normal door lock release operation at the last stage before the power is turned off, and are written in the 16 door lock operations before that. It is determined that 0 remains as it is (even if the data is slightly garbled). Accordingly, an alarm (warning signal) is output to the alarm output unit 52.

[0074]

According to the method for detecting intentional power cut-off according to the first aspect, intentional power cut-off for the purpose of releasing the internal interlock of the device is detected, an alarm output is output by voice, and the control center is notified. The notification, the automatic setting of the interlock for disabling the operation of the device, the partial self-destruction of the device, and the like can be executed, so that an unauthorized entry by an undesired person and the use of the device can be prevented.

Further, one new EEPROM can be added to a printed circuit board on which an arithmetic element is mounted, or an existing EEPROM can be added.
By using the vacant addresses of the ROM, it is possible to realize a small, lightweight and low cost. In addition, even after a long period of 10 years or more, the stored contents of the memory bits are not lost,
Even after a long period of time, it is possible to avoid a situation in which an intentional power-off is erroneously determined and a warning signal is not generated.

According to the anti-theft device of the second aspect, since the large-sized capacitor and individual circuit parts required for the conventional anti-theft device can be omitted, the overall configuration of the electronic control device including the anti-theft device is small. And the internal wiring is simplified, so that the cost of assembly and installation is reduced.

Further, since the electronic circuit relating to the keyless entry can be used as it is and the antitheft device can be constituted by only a slight change of the program stored in the arithmetic unit,
The circuit configuration, as well as the case of the arithmetic unit, can be shared between the vehicle and the vehicle without the anti-theft device. This further reduces the cost of installing the anti-theft device, including the mounting structure of the arithmetic device on the vehicle. Becomes possible.

Further, since the anti-theft device can be configured on a printed circuit board including an arithmetic element for executing an arithmetic program, the anti-theft device can be housed integrally in a non-openable housing for storing the arithmetic element and the like, and external wiring (Such as disconnection of the capacitor wiring in the conventional anti-theft device), the intentional power cutoff detection function cannot be released, and the reliability of the anti-theft device is improved.

Further, even if there is no risk of erroneously distinguishing between door lock and door lock even after a long period of time,
Very little power is drawn from the battery each time to remember the door lock / door unlock distinction.

Further, according to the intentional power-off detection method of claim 1 and the anti-theft device of claim 3, it is possible to distinguish between a normal lock operation / unlock operation and a vehicle door lock / door unlock. Since the address to be stored is changed for each normal lock operation or door lock operation, the deterioration of the data bit of the address for storing the normal lock operation / unlock operation or the distinction between the vehicle door lock / door unlock state is prevented. Can be delayed.

Therefore, the distinction between door lock / door unlock can be stored many times as compared with the case where writing / erasing is repeated with a data bit of a specific address of the EEPROM, and the EEPROM is inexpensive and has a small permissible number of times of writing / erasing.
Even when the OM is used, a long life and high reliability anti-theft device can be configured.

According to the intentional power cut-off detection method of claim 2 and the anti-theft device of claim 4, the data read from the EEPROM is identified through the majority operation, so that the data bit of the specific address of the EEPROM is used. Deterioration of data bits when writing / erasing is repeated,
A highly reliable identification operation can be maintained without being affected by sudden data corruption due to radiation or the like.

Therefore, a long-life and high-reliability anti-theft device can be constructed even when an inexpensive EEPROM having a small allowable number of write / erase operations is used.

[Brief description of the drawings]

FIG. 1 is an explanatory diagram of a basic configuration of the present invention.

FIG. 2 is an explanatory diagram of a configuration of an anti-theft device according to an embodiment.

FIG. 3 is a flowchart of the antitheft device of the embodiment.

FIG. 4 is a flowchart of the anti-theft device of another embodiment.

FIG. 5 is a part of a flowchart of the anti-theft device of still another embodiment.

FIG. 6 is an explanatory diagram of a configuration of a conventional anti-theft device.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 11 EEPROM 12 Control means 13 Writing means 14 Erasing means 15 Abnormality detecting means

Claims (4)

(57) [Claims] Each time a normal lock operation of a device is detected, a data address used as one or more data bits in the EEPROM is changed, and the changed data address is replaced with another one or more data bits in the EEPROM. After the registration, predetermined data is written to the registered data address, a normal unlock operation is detected, the predetermined data written to the data bit is erased, and the power supply of the device is connected. In this case, a data address registered in the another one or more data bits is read, and the one or more data bits are read based on the data address, and the read data is the predetermined data. A method of detecting a deliberate power-off, wherein a warning signal is generated when the power supply is identified. 2. The method according to claim 1, wherein when the power supply of the device is connected, the EE is detected.
Data is read from a plurality of data bits of the PROM. Even if the read data does not match the predetermined data, if the match is identified by at least a majority of data bits, the read data is read. A method for detecting intentional power cut-off, wherein the method is distinguished from the predetermined data. 3. An EEPROM (11) for registering a unique code for unlocking a door of a vehicle, and identifying a unique code operated on the vehicle, and identifying the unique code registered in the EEPROM (11). And a control means (12) for unlocking the door of the vehicle when they coincide with each other. Each time a door lock operation on the vehicle is detected, at least one of the EEPROM (11) is detected. Switching means for changing a data address used as a data bit of the EEPROM; registering means for registering the changed data address of the one or more data bits in another one or more data bits of the EEPROM; Writing means (13) for writing predetermined data to a data address; detecting a normal door unlock operation in the vehicle; Erasing means (14) for replacing data written in the one or more data bits with another predetermined data; and when the power supply is connected to the control means (12), the other one or more data bits Selecting means for reading a data address registered in the memory device and reading the one or more data bits based on the data address; and reading the data read by the selecting means with predetermined data of the door lock operation. An anti-theft device, comprising: an abnormality detection unit (15) for generating a warning signal when it is identified. 4. The anti-theft device according to claim 3, wherein the abnormality detecting means is configured to: when the power supply is connected to the control means, the EEPR.
The data is read from a plurality of data bits of the OM, and even if the read data does not match the predetermined data, if the match is identified by at least a majority of data bits, the read data is read. An anti-theft device comprising: majority decision means for identifying the predetermined data.