JPH0279111A - Electronic apparatus - Google Patents

Abstract

PURPOSE:To restore an apparatus to the state before the power supply to the apparatus is cut off when the power supply is cut off by automatically preserving the state of the apparatus and inputted various data until the power supply is cut off in a nonvolatile memory and reading out the preserved state when the power supply is restarted. CONSTITUTION:In the course of an automatic power supply cutting-off process, whether or not a key input is made from a keyboard 19 is discriminated and, when it is discriminated that a key input is made, the timer 100 of a CPU 10 is cleared and various processes are executed in accordance with the data from the keyboard 19. When no input is made from the keyboard 19 for fixed time, the CPU 10 sets a control signal P23 to a low level and turns off power sources VCC, VD24, and VPP27 (APSO function). However, since the power supply to a RAM 11 is maintained by a voltage VA26 in a power source section 13 and the RAM 11 is not turned off even when the APSO function works, the RAM 11 is preserved in a nonvolatile memory by the voltage VA26. Therefore, this apparatus can be restored to the state before the power supply is cut off.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to an electronic device that uses a battery as its power source and has a function of automatically shutting off the power to the device.

[Prior Art] Conventionally, in devices that use batteries such as dry batteries or NiCd batteries as power sources, in order to reduce battery consumption and extend the life of the battery, for example, when there is no key power for a certain period of time, the device can be disconnected from the battery. Automatic power cutoff function (Auto Pow) that cuts off the power supplied to each element and circuit in the
There is a device equipped with an er5hut Off function (hereinafter referred to as an APSO function).

In such devices, even when the power is cut off, the RAM portion of the device is backed up by an auxiliary power supply such as a battery, and the data written to the RAM when the main power is on is stored when the main power is turned on again. The method used was to hold it until it was turned on.

[Problems to be Solved by the Invention] Conventionally, in order to save data while the main power is off, data input when the main power is on is stored using a special key. It has been common practice to store data in a RAM that is supplied with power, depending on the operation or the like.

However, if you temporarily stop data input processing and leave the device for a certain period of time, the power to the device will be shut off without performing any processing to save the data, and all data entered up to that point will be lost. Otherwise, there was a problem that some of them would disappear.

The present invention has been made in view of the above-mentioned conventional example, and the present invention saves the state of the device and various input data in a non-volatile memory before the power of the device is automatically cut off. An object of the present invention is to provide an electronic device capable of reading out the saved state when the power of the device is turned on again and returning the device to the state when the power was turned off.

[Means for Solving the Problems] In order to achieve the above object, an electronic device of the present invention has the following configuration. In other words, it is an electronic device that uses a battery as a power source and has a function that automatically shuts off the power. , a saving means for storing the immediately previous device state in the storage means; and a recovery means for reading the device state from the storage means when the power to the device is turned on again to return the electronic device to the state immediately before the power was cut off. and means.

[Function] In the above configuration, the storage means stores data in a non-volatile manner even when the power is cut off, and when the power is automatically cut off, the device state immediately before that is stored in the storage means, and the device status is stored in the storage means. When the power is turned on again, the device status is read from the storage means to restore the electronic device to the state it was in just before the power was turned off.

[Embodiments] Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings.

[Description of Word Processor (Fig. 1)] Fig. 1 is a block diagram showing a schematic configuration of a word processor according to an embodiment of the present invention, and this word processor is equipped with a display section such as a liquid crystal display and a printing mechanism such as a printer. .

In the figure, 10 is a CPU such as a microprocessor that controls the entire word processor device via a CPU bus 21.
u, 11 is a RAM that is used as a work area for CPU10 and temporarily stores various data, etc.
It includes a flag 110 and a state storage unit 111 that stores the state of the device. 12 is a ROM that stores various data such as the CPU 10 control program and character fonts shown in the flowcharts of FIGS. 4 and 5.
It is.

Reference numeral 13 denotes a power supply section whose details are shown in FIGS. 2 and 3, which includes a battery as described later and supplies power to the entire electronic device. 22 is a power switch by which an operator turns on and off the power of the device; 24 is a display power supply voltage VD; 25 is a power supply voltage VA for the RAM 11; and 27 is a power supply voltage VPP for the printer 15. When the power supply unit 13 receives the power-off signal 23 from the CPU 10,
The automatic power off function (APSO) is executed by turning off the power supply voltages other than the voltage VA26 for RAM1l.

14 is a printer control unit that controls the printer 15 and prints out document data and graphic data input from a keyboard 19, etc.; 15 is a printer such as a thermal printer or a laser beam printer; 16 is the display 17
A display control unit 17 is a display device such as a liquid crystal or CRT that displays characters, figures, etc. as pattern data.

A keyboard control section 18 converts key data input from the keyboard 15 into code data and outputs the code data to the CPU bus 21.

To explain the operation of this device based on the above configuration, the code corresponding to the key input from the keyboard 19 is
When the key data is output to the CPU bus 21 by the keyboard control unit 18, the CPU 10 reads and judges the code, and executes processing according to the key data. At this time, for example,
If the key data is a character code, it is written to RAMII and the corresponding data is sent to the display control unit 16. Thereby, the display control section 16 reads out a display font corresponding to the data from the ROM 12 and displays it on the display 17. At this time, display data and RAM II are written simultaneously. Further, if necessary, the data input from the keyboard 19 is developed into a pattern using the printing font in the ROM 12, and the data is sent to the printer via the printer control unit 14.
5 can be output and recorded.

As mentioned above, power is supplied to each part of the device from the power supply unit 13, and Vcc25 is applied to the CPU 10, ROM1
2. It is supplied to the display control section 16, keyboard control section 18, and printer control section 14, which generally drives a general-purpose IC at +5■. In addition, the VD24 is the display control unit 1
6, and is, for example, a driver drive voltage for LCDs, etc., which have recently become popular as display devices. Vpp27 is a voltage for driving a motor or a thermal head in the printer 15, and is generally a higher voltage than VCC, and consumes a large amount of power.

This embodiment is effective for equipment that uses a battery as the main power source of the power supply unit 13 of equipment with the power supply configuration as in the above example, and is equipped with a device that converts the battery voltage into the various voltages described above. When performing voltage conversion in this way, the conversion circuit always consumes power, which reduces conversion efficiency and increases battery consumption, but in this example, this battery consumption is kept to a minimum. The purpose is to

In this embodiment, in the above-described configuration, if there is no input from the keyboard 19 for a certain period of time, the CPU
l0 is set to V, c24 . vo 24゜■Turn off PP27 (
APSO function). However, at this time, the power to RAMII is supplied by the voltage VA26 in the power supply unit 13. Since this power supply voltage VA26 is never turned off even if the APSO function is activated, RAMII
A26 holds the memory contents and functions as a non-volatile memory.

[Description of power supply section (Fig. 2)] FIG. 2 is a diagram showing an example of the circuit of the power supply section 13.

First, when the power switch 22 is turned on by being connected to the terminal (a) side, current starts flowing from the battery 31.
Resistor 38, 37 and also the emitter of transistor 39.
Charge is stored in capacitor 36 through the base.

At this time, the signal P23 is the output of the CPU 10 and is indeterminate, and the resistor 34 has fallen to the ground level, so the transistor 51 is turned off. Furthermore, since the voltage on the + side of the capacitor 36 is at a low level for a certain period of time after the aforementioned capacitor 36 starts charging (after the power switch 22 is turned on), the transistor 39 can be kept sufficiently turned on. .

In this way, when the transistor 39 is on, the battery 31 is connected to the control terminal 40 of the voltage level converter 41.
When current flows into the voltage level converter 41, the voltage level converter 41 starts operating. As a result, the voltage level converter 41
A voltage Vcc25 converted from the battery voltage is output.

When this Vcc25 is output, as shown in FIG.
CPU i o powered by Vcc25
, display control section 16, ROM 12, keyboard control section 18
, the printer control unit 14 starts operating, and the CPU I/O
Immediately after starting the operation, the signal P23 is set to high level and output. This signal P23 turns on the transistor 51 via the resistor 33. As a result, the charge accumulated in the capacitor 36 is discharged to the ground via the diode 32 and the resistor 35, and the transistor 39 can continue to be in the on state, and the voltage level converter 41 performs a conversion operation. are executed continuously.

At the same time, the transistor 46 also connects the resistor 45,
Since a current flows toward the transistor 51 via the resistor 44 and the diode 43, the on state can be maintained. As a result, each control terminal 56.52 of the voltage level converter 47.49, similar to the voltage level converter 41,
current flows into. As a result, the voltage level converters 47 and 49 start operating, and each output has V. 24°V
pp27 is output. As a result, the display 11 in FIG.
．． Power is supplied to the printers 13, allowing them to operate.

Here, each of the electrolytic capacitors connected to the output terminals of Vcc25, Vo24, and Vpp27 is
This is to stabilize each output voltage.

Further, in this example, VC, 25, VP, 27 are ten voltages, and VD24 is one voltage. Further, the voltage VA26 supplied to RAMII is determined by the Zener diode 28 when the voltage of the battery 31 is high, and when the voltage level of the battery 31 is lower than the Zener voltage of the diode 28, VA26 is equal to the voltage of the battery 31. Become. Also, VA26 is Vcc when the power switch 22 is on.
25 is output, the voltage level becomes equal to that of VcC25 due to the action of diode 3o.

Further, the capacitor 53 is connected to the diode 54 from the battery 31.
It is charged through the resistor 55. This capacitor 53 is
This is effective for retaining the contents of the RAM 11 when replacing the battery 31. Therefore, the power supply section 1 shown in FIG.
In the circuit No. 3, the voltage VA26 remains output despite the state of the power switch 22 and the power is automatically cut off, so the contents of RAMII remain retained.

[Operation Description (FIGS. 4 to 6)] FIG. 4 is a flowchart showing automatic power-off processing in the device of the embodiment, and a control program for the CPU 10 that executes this processing is stored in the ROM 12.

This process shows the process when the power switch 22 is turned on, the voltage supplied to each part rises, and each part is operating. First, in step S1, it is determined whether there is any key force on the keyboard 19, If it is determined that there is key human power, the process proceeds to step S2, where the CPU timer 100 is cleared and the process proceeds to step S3. In this step S3, each fffl process is executed according to the data input from the keyboard 19.

This processing includes, for example, displaying key manual data on the display 17, writing input data and display data to RAMII, or outputting all or part of the input data to the printer 15 as necessary. , which executes the functions provided by the device.

When the process is completed, the process returns to step Sl. In this way, if the above processing is repeated between step 81 and step S3, various data will be written to RAM II.

Further, if it is determined in step S1 that there is no key human power, the process moves to step S4, and the timer 100 for measuring time is activated.
Start. In step S5, it is determined whether the timed value of the timer exceeds a predetermined value, and if it does not, the process returns to step S1.

If the clock value exceeds the predetermined value in step S5, the process advances to step S6, and each parameter of the current state of the device is RA
Write to the MII state storage unit 111. The parameters to be remembered here include the key input mode or
It includes the position of the carriage for printing by the printer 15, the line feed position, and display data to be displayed on the display 17.

Next, in step S7, this device turns on the APF flag 110 indicating that the APSO function has been activated, and in step S8, the signal P23 is set to low level, and all power supplies other than A26 output from the power supply section 13 are turned on. Turn off the voltage.

FIG. 5 is a flowchart showing the operation immediately after the power is turned on (power switch 22 is turned on), and a control program for executing this process is stored in the ROM 12.

The part explained in FIG. 5 should be executed before the part explained in FIG.
I postponed it for the sake of explanation.

First, in step Sll, the power switch 22 is turned on.

Here, there are two possible states of the power switch 22 being turned on. The first state is when the power switch 22 is normally off and then turned on, and the second method is when the power switch 22 is automatically turned off and then turned on after being turned off. .

In step S12, the CPU 10 performs various initializations of the device. Next, in step S13, the specific address where the APF flag 110 was written is read out, and depending on whether the flag 110 is on, it is checked whether the APSO function was activated before the power switch 22 was turned on. If it is not working (if the APF flag 110 is off), the process moves to step S19 and the normal processing routine of this device is executed.

On the other hand, if the APF flag 110 is turned off in step S13, the process advances to step S14, and the display 11 displays that the APSO function was previously activated. Next step S1
5 displays whether to set the state before the APSO function worked on the device, and allows you to select whether to start operation from the state before the APSO function worked or to return to the normal state. ing.

If it is set not to set the previous state in step S15, the process moves to step S18, and A
The PF flag 110 is turned off and the process proceeds to the normal processing routine of step S19. Further, when setting the previous state in step S15, the process advances to step S16, and the RAM
In step S1, information regarding the device state immediately before power cutoff, which is stored in the state storage unit 111 of II, is read out.
Step 7 sets the device to a state according to the information. After that, the APF flag is turned off in step S18, and the process moves to step S19.

Figure 6 shows the time (t) until the automatic power cutoff function is executed.
w) This flowchart is stored in the ROM 12.

In step S21, it is checked whether there is any key force on the keyboard 19, and if there is any key force, the process moves to step S22 and the timer 100 of the CPU 10 is cleared. In step S23, it is determined whether the key manual data is in a mode for setting time tw, and if it is not in this mode, the process proceeds to step S24, where various processes are performed according to the input data, and the process returns to step S21.

If it is the time tw setting mode, the process advances to step S25;
The value of the time tw is entered and set from the keyboard 19, and in step S26, the value is stored in the time memory 1 of the RAM 11.
Write to 12. After that, return to step S2L again,
Determine if you have key human resources.

On the other hand, if it is determined in step S21 that there is no key power, the process proceeds to step S27, and time measurement by the timer 100 of the CPU 10 is started. Next, in step S28, the time value of the timer 100 and the value tw of the time memory 112 are compared, and if the time value of the timer 100 is larger, the process moves to step S6 described in FIG. 4. Also timer 10
If the measured value of 0 is smaller, the process returns to step S21 and the above-described operation is executed.

[Description of other configurations of power supply section (FIG. 3)] FIG. 3 is a diagram showing another configuration example of the power supply section 13, and parts common to those in FIG. 2 are indicated by the same symbols.

First, when the power switch 22 is turned on as shown in the figure, the capacitor 64 is charged from the battery 31 through the resistor 61, 62 and between the transistor 63 and its base.

At this time, the transistor 65 is the transistor 5 in FIG.
It is in the off state as in 1. Then, when the voltage at the collector of the transistor 63 rises, the reference voltage generator 66 outputs a predetermined reference voltage.

This voltage is input to voltage comparators 67 to 69. For example, voltage comparator 74 outputs voltage output Vpp27 to resistors 71 and 72.
The voltage converter 67 is controlled by comparing the divided voltage with a reference voltage 73. In this way, the output voltage VPP
27 is kept at a constant voltage. Other comparators 75
The relationship between the voltage comparator 68 and the comparator 76 and the voltage comparator 69 is also similar.

In addition, when voltage Vcc25 is not generated, voltage ■8
is the resistance 84. from the battery 85. It is output via diode 83. On the other hand, when Vcc25 is generated, VA
26 is supplied from VCC 25 through a diode 82. Here, if the voltage of the battery 85 is ■, then ■CC
>VI]. In addition, capacitors 91 to 94 stabilize each voltage.

Further, the resistor 95 is a resistor for discharging the capacitor 96. The fuse 97 is cut off when the current value supplied from the battery 31 becomes less than a predetermined value, and is intended to protect the equipment.

In this way, other embodiments include batteries 31 and 85, where battery 31 is the main power supplied to the entire device, and battery 85 is the battery supplied only to VA 26, and the power from battery 31 is supplied. Even if the supply is cut off, VA26 allows R
The memory contents of AMII can be retained.

As explained above, according to this embodiment, even when the power is automatically cut off, the information input in the past is not lost, and by turning on the power switch again, the information can be saved as needed. You can set the device to the state it was in before the shutdown by calling .

This allows the user to use the device without being particularly aware of the automatic power-off function.

Another advantage is that the waiting time for shutting off the power can be set to an arbitrary value.

[Effects of the Invention] As explained above, according to the present invention, before the power to the device is automatically cut off, the state of the device and various input data can be saved in a non-volatile memory. Ok,
This has the effect that when the power to the device is turned on again, the saved state can be read out and the device can be restored to the state it was in when the power was turned off.

[Brief Description of the Drawings] Figure 1 is a block diagram showing the schematic configuration of the word processor of this embodiment, Figure 2 is a circuit diagram showing the first embodiment of the power supply section, and Figure 3 is the power supply section of the first embodiment. A circuit configuration diagram showing the second embodiment; FIG. 4 is a flowchart showing power-off processing in the embodiment; FIG. 5 is a flowchart showing initial processing after power-on;
FIG. 6 is a flowchart showing another embodiment of the power-off process. In the figure, 10...CPU, 11...RAM, 12...
・R0M, 13...Power supply unit, 14...Printer control unit, 15...Printer, 16...Display control unit, I7
...Display unit, 18...Keyboard control section, 1...
・Keyboard, 21...Battery, 22...Power switch, 23...Signal P, 24...Power supply voltage VD, 25
...Power supply voltage VCC526...Power supply voltage VA, 27
...Power supply voltage Vpp, 85...Battery, 100...
Timer, 110... APF flag, 111... State storage section, 112... Time memory. Figure 4

Claims (2)

[Claims] (1) An electronic device that uses a battery as a power source and has a function that automatically shuts off the power, including a storage means that stores data in a non-volatile manner even when the power is cut off, and that automatically shuts off the power. save means for storing the immediately previous device state in the storage means; and when the power to the device is turned on again, the device state is read from the storage means to restore the electronic device to the state immediately before the power was cut off. An electronic device comprising a return means. (2) The electronic device according to claim 1, further comprising selection means for selecting whether or not to activate the recovery means when the power of the device is turned on.