JPH07104988B2 - Code setting method - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION <Industrial application> The present invention relates to a code setting method, and in particular, code setting in an anti-theft device that enables normal operation of a device only when a personal identification code attached to the device is input. Regarding the scheme.

<Prior Art> In order to prevent theft of in-vehicle equipment,
There is a device in which a device-specific secret code is attached so that normal operation is possible only when a code matching the secret code is input.

<Problems to be Solved by the Invention> In a conventional antitheft device, a personal identification code unique to a device is stored in advance in a nonvolatile memory as an external memory at the factory when the device is manufactured. Therefore, there is a problem that the device user (user) cannot set his / her favorite personal identification code.

In addition, since the conventional anti-theft device uses an external memory in which a personal identification code is stored from the beginning,
There is also a problem that the anti-theft function is easily invalidated by replacing the external memory with another external memory in which the secret code is stored.

In addition, in order to write the personal identification code to the external memory, it is necessary to provide an external programming device in the factory and use the device to write the personal identification code. There is also the problem that it takes time and money to replace the external memory.

From the above, it is an object of the present invention to provide a code setting method in which the user can set his / her own personal identification code, cannot easily disable the theft prevention function, and does not need to set the personal identification code at the factory. Is.

<Means for Solving Problems> FIG. 1 is a block diagram of a system when the present invention is applied to a vehicle-mounted tape player with a radio.

11 is an electrically erasable and writable non-volatile memory (for example, EEPROM), 12 is a microcomputer, 13 is a main body of a tape player with an on-vehicle radio, 14 is an operation unit provided with each key, 15 is a display unit, Reference numeral 16 is a battery on / off detector, 17 is an ignition on / off detector, and 18 is a power switch on / off detector of the device.

<Operation> When the battery is connected and both the ignition switch and the power switch are turned on, the microcomputer 12 checks whether a predetermined value (initial setting value) is stored in the first address of the nonvolatile memory 11 and stores it. If so, the factory code stored in the ROM 12b in advance (first
Code) FCD is written in the first address of the nonvolatile memory 11 by a predetermined key operation. And the first code FC
Writing of the user code (second code) UCD into the nonvolatile memory 11 is permitted, provided that D is stored in the nonvolatile memory 11.

When the device is actually used, the microcomputer 12 determines that the first code FCD is stored in the non-volatile memory 11 and that the code that matches the second code UCD stored in the non-volatile memory 11 is the operation unit. The tape player 13 with an on-vehicle radio can be normally operated on condition that the tape player 13 is inputted from 14.

<Embodiment> FIG. 1 is a block diagram of a system when the present invention is applied to an on-vehicle tape player with a radio.

11 is an electrically erasable and writable non-volatile memory (for example, EEPROM). The first and second addresses 11a and 11b of the non-volatile memory 11 have predetermined first and second addresses at the initial stage.
Value (initial setting value) is stored, and a first code FCD called a factory code is set in the first address 11a by a code setting operation described later, and a second code called a user code is set in the second address 11b. 2-code UCD is set.

Reference numeral 12 denotes a microcomputer, which includes a processor 12a, a ROM 12b in which a control program and a factory code FCD are stored in advance, a RAM 12c for storing processing results, etc., and controls a radio, a tape player, etc., and an antitheft control described later. To execute.

13 is a main body of a tape player with an on-vehicle radio,
13a is a tuner, 13b is a PLL circuit, and 13c is a cassette mechanical control unit. The tuner 13a, the PLL circuit 13b, and the radio control function of the microcomputer 12 constitute a synthesizer-type tuner.

An operation unit 14 is provided with various keys for controlling the radio and tape player, and various keys operated to prevent theft. Reference numeral 15 indicates a radio frequency, time, and the like, and a display portion that performs a predetermined display when setting or inputting an anti-theft code, 16 a battery on / off detection portion that detects whether or not a battery is connected, and 17 a An on / off detector for detecting whether the ignition switch is on / off, and a power switch on / off detector 18 for detecting whether the power switch of the device is on / off.

FIG. 2 is a flow chart of processing of the code setting method according to the present invention. The overall operation of FIG. 1 will be described below with reference to the flowchart of FIG.

When the ignition switch and the power switch of the device are both turned on while the battery is connected (step 101), the processor 12a of the microcomputer 12 stores the first initial setting value in the first address 11a of the nonvolatile memory 11. It is checked (step 102). It should be noted that this step 102 is for checking whether or not the non-volatile memory specified for anti-theft is installed in the device, and if the non-volatile memory 11 is specified, the first address 11a The first initial set value is stored in. However, if the factory code FCD is already written even if the non-volatile memory 11 is specified, or if the thief replaces the legitimate non-volatile memory 11 with another non-specified non-volatile memory. Does not store the first initial setting value.

Now, if the first initial set value is stored, in other words, if the non-volatile memory 11 is a specific memory and the factory code FCD is not written, the processor 12a causes the display unit 15 to display a predetermined value. Is displayed, for example, a certain character or numeral is displayed (step 103).

The user operates the predetermined key (referred to as the A key) 14a on the operation unit 14 while viewing the display (step 104).

When the A key is pressed, the processor 12a automatically writes the factory code FCD stored in the ROM 12b in advance at the first address 11a of the nonvolatile memory 11 (step 10
5) Make sure that the factory code FCD has been written (validly) to the non-volatile memory 11 (step 10).
6) If the factory code FCD has not been written correctly, it will not operate normally and will be in an error state (step 107). If it has been written correctly, it will jump to step 111 and it will be in a user code writable state. It should be noted that the only way to clear the error state in step 107 is to send it for repair.

On the other hand, in step 102, the first non-volatile memory 11
If the first initialization value is not stored in the address 11a, the processor 12a determines that the content of the first address is the factory code F.
Check if it matches the CD (step 10
8).

If it does not match the factory code FCD, the thief replaces the regular non-volatile memory with another non-volatile memory, and normal operation is not performed.
9).

If the factory code FCD is stored at the first address 11a,
It is checked whether or not the second initial setting value is stored in the second address 11b of the non-volatile memory 11 (step 110).

After writing the factory code FCD in step 105, if the code setting operation is stopped for some reason and the ignition switch and power switch are turned on again, the second
If the second initial setting value is still stored in the address 11b and the user code UCD, which is the second code, is set in steps 111 to 114 described later, the user is stored in the second address 11b. The code UCD is stored.

Now, if the second initial setting value is stored in the second address 11b, or if the factory code F is set correctly in step 106.
When the CD is written at the first address 11a, the processor 12a displays a predetermined message to inform the user that the user code is ready for writing (step 11).
1).

The user identifies that it is in the writable state, presses the code setting key on the operation unit 14, and inputs his / her favorite code number (user code) UCD (step 112).

When the user code UCD is input, the processor 12a stores the user code UCD in the second address 11b of the non-volatile memory 11 (step 113) and stores the user code UCD in the non-volatile memory 11 on the display unit 15. The completion is displayed (step 114). Note that the user code UCD may be encrypted and stored so that it cannot be easily detected.

With the above, the setting of the factory code FCD and the user code UCD to the nonvolatile memory 11 is completed, and if a code matching the user code is input thereafter, the tape player with radio 13
Can operate normally. Hereinafter, operations and processing for operating the device will be described.

If the factory code FCD and the user code UCD are set in the nonvolatile memory 11, the second address 11 of the nonvolatile memory 11
Since the second initial setting value is not stored in b (the user code UCD is stored), “NO” is obtained in step 110, and the processor 12a performs a predetermined display on the display unit 15 and compares the user code with the user. Notify that it is in a state (step 115).

In this user code collation state, or step
When the setting of the user code in 114 is completed, the user inputs a predetermined code number using the code setting key of the operation unit 14 (step 116).

When the code is input, the processor 12a compares the input code number with the user code UCD stored in the second address 11b of the nonvolatile memory 11 (step 11).
7) If the input code number matches the user code UCD, the car stereo system shown in FIG. 1 operates as a normal tape player with radio (step 118).

On the other hand, if the code number corresponding to the user code UCD is not input in step 117, the processor 12a checks whether it is the third code input (step 119).
The code can be input up to three times continuously.

If the code is not entered the third time, the code is displayed on the display unit 15 (step 120), and then step 116.
The subsequent operations and processes are repeated.

However, even if the third code is entered, the user code UC
If a code that matches D is not entered, it will be in an error state as if a suspicious person is entering the code, for example you can not enter the code again until 8 hours have passed, and you can enter the code again when 8 hours have passed (Steps 121 and 122). That is, in most cases, a legitimate user can input the correct code by one operation, and even if it is wrong, the correct code can be input at the second or third time.
However, if an unauthorized user inputs the code many times, the input code does not match the user code. Therefore, if the codes do not match three times in a row, the code cannot be input until eight hours have passed so that an unauthorized user cannot use the device.

The error state waiting for the lapse of 8 hours is maintained even if the power is turned off and then input again.

By the way, there is a case where the user code once set is desired to be changed to another code. In such a case, in the normal function state (step 118), the radio reception state is set by operating the switch, and then a specific key (called B key) 14b is operated to set the user code writable state, and step 11
A new user code is set by 1 to 114.

<Effects of the Invention> As described above, according to the present invention, the factory code can be written in the nonvolatile memory when the initial setting value is stored in the specific position of the nonvolatile memory, and the factory code is stored in the nonvolatile memory. Since it is configured to allow writing of the user code to the non-volatile memory on condition that it is stored, the user can set his / her own personal identification code (user code), and even if the non-volatile memory is simply replaced. Since the anti-theft function cannot be disabled, the anti-theft function can be strengthened, and further, the productivity and the serviceability of the repair can be improved without the need to set the secret code in the manufacturing factory or the repair shop.

[Brief description of drawings]

FIG. 1 is a block diagram of a car stereo when the present invention is applied to a vehicle-mounted tape player with a radio, and FIG. 2 is a flow chart of processing of the present invention. 11 …… Rewritable non-volatile memory, 12 …… Microcomputer, 13 …… Car radio tape player main unit, 14 …… Operator, 15 …… Display, FCD …… Factory code, UCD …… User code

Claims (3)

[Claims] 1. A writable non-volatile memory stores a first code peculiar to a device, and a code input when the device is used is a second code preset in the non-volatile memory. In the code setting method in the anti-theft device that enables normal operation of the device only when the above-mentioned situation is satisfied, only when a predetermined value is stored in a specific position of the non-volatile memory, A code setting method characterized by enabling writing of the code of. 2. A first code is stored in a ROM of a device in advance, and when the writable state is achieved, the first code is written in the nonvolatile memory by a predetermined key operation. The code setting method according to claim 1. 3. The method according to claim 2, wherein writing of the second code into the non-volatile memory is permitted, provided that the first code is stored in the non-volatile memory. Code setting method described in section.