JPH0594238A - Data protection device for electronic equipment - Google Patents

Abstract

PURPOSE:To provide the data protection device for the electronic equipment which can surely protect the data in a data storage part backed up by a power source and surely turn OFF the power source. CONSTITUTION:When a power switch 8 is turned ON and electric power begins to be supplied, a relay contact 23 connected in parallel to the power switch 8 is made to supply the electric power continuously even after the power switch 8 is turned OFF. When the power switch 8 is turned OFF, the data in the RAM 12 are automatically stored on a disk device 19 and a relay 22 is stopped so as to break the relay contact 23, thereby automatically stopping supplying the electric power.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a data protection device for an electronic device that protects data from data destruction of a RAM (random access memory) whose power is backed up when the power is off.

[0002]

2. Description of the Related Art Conventionally, in an electronic device having a RAM whose power source is backed up, the data in the RAM is normally backed up by a battery which is a backup power source even when the main power source of the electronic device is turned off.
Since the capacity of the battery is limited, it is impossible to back up for a long time exceeding the limit, and in some cases, the data in the RAM may be destroyed and lost. Therefore, in consideration of the fact that the main power supply remains off for a long time, the data in the RAM can be stored in a floppy disk or the like by performing a predetermined key operation before the user turns off the main power supply. Some have a data protection device that protects data by storing it in a non-volatile storage medium. Then, after confirming that the data storage is completed, the operator turns off the power. In such an electronic device, when the main power is turned on, even if the data in the RAM is destroyed and lost, the main power is turned off by performing a key operation or the like to restore the data stored in the storage medium. It is possible to return to the state before doing.

[0003]

However, the conventional data protection device for an electronic device is complicated because it requires a key operation for saving data in a storage medium before turning off the main power source. If the operation is forgotten, it cannot be restored when the above data is lost beyond the capacity of the battery. In addition, it is annoying for the operator that waiting time occurs until the power is turned off after confirming that the saving is completed and turning off the power, and in the worst case it is necessary to perform other work during the waiting time. I might forget to turn off the power switch.

The present invention has been made in view of the problems of the prior art as described above, and can protect the data in the data storage unit backed up by the power supply without performing a complicated operation and surely turn off the power. It is an object of the present invention to provide a data protection device for an electronic device that is capable of

[0005]

A data protection device for an electronic apparatus according to the present invention comprises a control section, a data storage section controlled by the control section and backed up by a backup power source, and the control via a power supply circuit. In an electronic device equipped with a power switch for turning on / off power supply to the unit, a readable / writable nonvolatile storage medium connected to the control unit and a relay contact connected in parallel to the power switch. A relay that turns on and off the power switch, a detection circuit that connects the input terminal of the power switch and the control unit when the power switch is turned off, and the relay in response to the start of power supply to the control unit. In response to the input of the OFF signal of the power switch through the relay control means for driving the relay contact to turn on the relay contact and the detection circuit,
After storing the data of the data storage unit in the storage medium and executing the data storage processing, the data storage control unit is provided to stop the drive to the relay and turn off the relay contact.

[0006]

According to the present invention having such a structure, when the power switch is turned on and the supply of power to the control unit is started, the contacts connected in parallel to the power switch are turned on by the relay control means to turn on the power switch. Even if is turned off, the power supply to the control unit is maintained. When the power switch is turned off, the switch detection circuit detects that the power switch has been turned off, and in response to this detection, the data in the data storage unit is automatically stored in the nonvolatile storage medium. As a result, the data is stored in the non-volatile storage medium even when the capacity of the battery is exceeded and the power switch is not turned on for a long time. Then, after that, the driving of the relay is stopped, the relay contact is turned off, and the power supply to the electronic device is automatically stopped.

[0007]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT An embodiment in which the present invention is applied to an electronic cash register as an electronic device will be described below with reference to the drawings. FIG. 2 is an external view of an electronic cash register. The main body 1 is provided with a keyboard 2 for inputting codes, prices, etc. of products to be sold, and the price and total of the products keyed in on the upper surface. An operator display 3 and a customer display 4 for displaying the amount of money and the like are provided. An R / J printer 5 for printing on receipt paper and journal paper is provided inside the main body 1. Further, a drawer 6 for storing cash etc. on the lower surface of the main body 1.
Is installed. In the figure, 7 is a power plug, and 8 is a main power switch.

FIG. 1 is an electrical hardware block diagram of the electronic cash register of this embodiment. The CPU 9 which is a control unit is the center of the present device which executes arithmetic processing on various data input from the keyboard 2 and the disk device 19 which is a non-volatile storage medium. The CPU 9 includes an address bus and a data bus. , A ROM 11 and a data storage unit RA via a bus line 10 composed of control lines.
Each memory of M12 is connected. The ROM 11 stores fixed data such as program data and character generator data for the CPU 9 to control each unit. The RAM 12 is provided with various memories for storing variable data such as a print buffer, a display buffer, a memory for accumulating sales data of registered products for sale, and the like. The RAM 12 is backed up by the battery 13 when the main power is off.

A signal is output to the keyboard controller 14 for controlling the keyboard 2, the display controller 15 for controlling the respective display devices 3, 4, the printer controller 16 for controlling the R / J printer 5, and the drawer opening device 17. I / O port 18 and disk device 19 for
A disk controller 20 for controlling the reading and writing of data is connected to the CPU 9 via the bus line. The disk device 1 referred to in this embodiment
9 means a hard disk device. Further, the disk device 19 is formed with a copy flag area 21 for storing a copy flag which is identification data for identifying whether or not the data in the RAM 12 is saved in the disk device 19. Further, the CPU 9 has the bus line and I / O.
A relay 22 is connected via the port 18. The relay contact 23 of the relay 22 is connected in parallel with the power switch 8. When the power switch 8 is turned on, the contacts are closed, so that the power circuit 24 and the commercial AC power source are electrically connected to each other when the power plug 7 is inserted into the outlet. When connected to a commercial AC power supply, the power supply circuit 24 supplies a desired DC power supply from the AC to the CPU 9 and the like. With this power supply, the CPU
Various elements including 9 become operable. The power switch 8 has a detection terminal 25 for detecting power off.
And a signal line 26 to the I / O port 18. When the power is turned off by this detection circuit, an off signal indicating that is input to the I / O port 18, and the CPU checks that signal at regular time intervals to detect that the power switch 8 has been turned off.

FIG. 3 shows the power-on (power-on) of this embodiment.
It is a flow chart which shows processing at the time. This processing is executed by turning on the power switch 8 with the power plug 7 plugged in the outlet. First, in step 100, it is determined whether or not the startup is normal. This is a normal start-up if the power switch 8 is still being operated, but a specific operation, such as the setting of the DIP switch or the operation of the power switch 8 with a predetermined key pressed, is performed. Distinguish by switch or key signal. If it is a special startup, other processing is executed in step 101. The other processing is RAM
There is processing such as clearing the contents of 12. Step 1
If it is determined in 01 that the startup is normal, the relay 22 is driven in step 102, which is the relay control means, to turn on the relay contact 23, and in step 103, the data in the RAM 12 that should have been backed up by the battery is Investigate if it is destroyed. This investigation is performed, for example, by storing fixed data in a predetermined area of the RAM 12 in advance, reading the data, and checking whether or not the data is the stored data. If the read data is not the stored data, it can be determined that the data in the RAM 12 is destroyed. The result is determined in step 104, and if not destroyed, normal program processing is executed in step 109.

If it is determined in step 104 that the data is destroyed, it is determined in step 105 whether the data in the RAM 12 is reserved by referring to the copy flag memory 21 of the disk device 19. In this embodiment, when 1 is set in the copy flag memory 21, it is assumed that the data in the RAM 12 is normally stored in the disk device 19. Therefore, if 1 is not set in the copy flag memory 21, the data in the RAM 12 does not exist in the disk device 19 either, so that a message indicating an abnormality of the memory is displayed on the display devices 3 and 4 in step 106. If 1 is set in the copy flag memory 21, the data in the RAM 12 is stored in the disk device 19, so in step 107 the data stored in the disk device 19 is read via the disk controller and transferred to the RAM 12. Then, it is stored and the data is restored. Then, in step 108, the flag of the copy flag memory 21 of the disk device 19 is cleared, and in step 109, normal program processing is executed.

FIG. 4 shows the power supply shutdown (power off) of this embodiment.
It is a flow chart which shows processing at the time. This process is executed by periodically checking the state of the power switch 8 from the signal input to the I / O port via the detection terminal 25 and the signal line 26 and detecting that the power switch 8 is off. is there. In step 110, the timer is started.
This is a software timer with a counter formed in the RAM 12. In step 111, the process of storing the data stored in the RAM 12 in the disk device 19 via the disk controller 20 is started, and in step 112 it is determined whether or not the final address of the address occupied by the RAM 12 has been stored in the disk device 19. It is determined whether the saving is completed. If it has not ended, it is determined in step 113 whether the timer value has reached a predetermined value.
The memory data saving process is repeated until the saving ends or the timer value reaches a predetermined value. Step 11
If the timer value reaches the specified value in step 3, step 1
At 15 the drive of the relay 22 is stopped and the relay contact 23 is turned off. In this case, it means that the data in the RAM 12 cannot be saved in the disk device 19. If it is determined in step 112 that the storage has been completed, in step 114 the copy flag memory 21 of the disk device 19 is stored.
Is set to 1, and in step 115, the energization of the relay 22 is stopped and the relay contact 23 is turned off. In this case, it means that the data in the RAM 12 has been saved in the disk device 19. When the relay contact 23 is turned off, the power supply circuit 24 is disconnected from the AC power supply, the DC power supply to the CPU 9 and the like is stopped, and the CPU 9 becomes inoperable. Note that steps 111, 112, and 115 are data storage control means.

Next, the operation of this embodiment will be described. When the power switch 8 is turned on while the power plug 7 is plugged into the outlet, the switch contacts are closed and the power circuit 24
The power is supplied from the CPU 9 to enable the CPU 9 and the like to operate.
In the normal case, the relay 22 is energized by the control of the CPU 9 and the relay contact 23 is turned on. Further, it is automatically checked whether the data in the RAM 12 that should have been backed up by the battery is destroyed. Then, if not destroyed, normal processing is started. For example, the sales data of each sale product registered for sale by the key operation of the keyboard 2 is accumulated in the RAM 12. Further, the price of the sold product, the total price, etc. are displayed on the display devices 3 and 4, and the receipt is issued. For example, when the data in the RAM 12 is destroyed due to insufficient battery capacity, the copy flag memory 21 of the disk device 19 is stored.
It is checked whether or not the data in the RAM 12 is stored in the disk device 19 and if the data is not stored in the disk device 19, the memory abnormality is displayed on the display devices 3 and 4 without performing unnecessary data restoration processing. In this case, the power is once turned off, special startup such as clearing the RAM 12 is performed, and then restoration processing is executed by key input or the like based on the data printed on the journal paper. In addition, the disk device 19
Data stored in the disk device 19 is automatically transferred to the RAM 12 and stored in the RAM 12.
12 data are restored.

Power switch 8
When is turned off, the contact of the power switch 8 is opened.
However, since the relay contact 23 remains on, the power supply from the power supply circuit 24 is continued. And CPU
When the RAM 9 detects the OFF operation of the power switch 8, the RAM 1
The process of storing the second data in the disk device 19 is executed. Also, timer monitoring is performed to monitor the recording abnormality of the disk. After that, when the storage in the disk is completed, 1 is set in the copy flag memory 21 to indicate this, and if the time is out, the relay 22 is not energized without setting 1 in the copy flag memory 21. By stopping the energization of the relay 22, the relay contact 23 is turned off, the power supply from the power supply circuit 24 is stopped, and the CPU 9 and the like malfunction.

As described above, in the present invention, the data of the RAM 12 backed up by the battery is automatically stored and saved in the disk device 19 in response to the power-off operation, so that the battery capacity is insufficient when the power is turned off. Even if the data in the RAM 12 is destroyed and lost due to a failure or the like, the data can be reliably restored when the power is turned on. In addition, since data is automatically saved and restored, there is no troublesome key operation or inconvenience of forgetting the operation. Further, when the saving fails, the restoration processing is not performed and the fact is notified, so that it is possible to prevent a problem that the normal processing is executed with the destroyed data.

The present invention is not limited to the above embodiment. For example, although the electronic cash register has been described in the present embodiment, the present invention is not limited to this, and can be applied to all electronic devices having a RAM whose power is backed up.

[0017]

As described above, according to the present invention, since the data protection of the memory whose power is backed up can be automatically executed by turning off the power switch, complicated operation can be omitted.
It is possible to provide a highly reliable data protection device for an electronic device that can prevent operation mistakes and can surely turn off the power after executing the data storage process.

[Brief description of drawings]

FIG. 1 is a hardware configuration diagram of an electronic cash register showing an embodiment of the present invention.

FIG. 2 is an external view of an electronic cash register in the embodiment.

FIG. 3 is a flowchart showing a process at power-on in the embodiment.

FIG. 4 is a flowchart showing a process when the power supply is turned off in the embodiment.

[Explanation of symbols]

 9 CPU 12 RAM 13 Battery 19 Disk device 21 Copy flag memory 22 Relay 23 Relay contact

Claims (1)

[Claims] 1. A control unit, a data storage unit controlled by the control unit and backed up by a backup power supply, and a power switch for turning on / off power supply to the control unit via a power supply circuit. An electronic device comprising: a read / write non-volatile storage medium connected to the control unit, and a relay contact connected in parallel to the power switch to turn on / off.
A relay that turns off, a detection circuit that connects an input terminal of the power switch and a control unit when the power switch is turned off, and the relay is driven in response to the start of power supply to the control unit. Relay control means for turning on the relay contact by means of an electric power switch, and after storing the data of the data storage unit in the storage medium and executing a data saving process in response to the input of an off signal of the power switch via the detection circuit. A data protection device for electronic equipment, comprising: data storage control means for stopping driving of the relay and turning off a relay contact.