JPH0441381Y2 - - Google Patents

Description

[Detailed description of the invention] (Industrial application field) The present invention is a power-off system for preventing the power switch of data processing equipment, including office computers and personal computers, from being turned off due to operator's erroneous operation. Regarding circuit improvement.

(Prior Art) In low-cost data processing apparatuses such as office computers and personal computers, a method as shown in FIG. 3 or 4 has been used to prevent power interruption due to operator's erroneous operation.

In FIG. 3a, the power switch of the data processing device is attached to the side panel or rear panel of the device so that the power switch cannot be easily operated, thereby preventing power outage due to erroneous operation. Further, in FIG. 3B, the power is turned on and off using a key switch, and by removing the key after the power is turned on, it is possible to prevent the power from being turned off due to erroneous operation by a third party.

However, in the method shown in Figure 3 a or b, the power-off operation is always effective even when the system is in operation and, for example, file update work is being performed for a long time, so it is difficult for the operator to judge the situation. In some cases, the power was turned off due to an error in the process, such as determining that the process was completed even though it was in progress. Therefore, recently, a device has been developed that uses software to lock the power off and prevent the power from being cut off due to erroneous operation of the power switch while the system is running and processing continues.

FIG. 4 shows an example of a conventional program-based power cutoff device. In FIG. 4a, 1 is a power supply device, 2 is a control unit of the data processing device, 3 is a power on switch, and 6 is a power off switch. Since the power-on switch 3 is connected to the OV (ground) level in the control unit 2, it is always valid, and when pressed, the power is turned on.

The power cutoff switch 6 is connected to the power cutoff lock control section 14.
Since the control unit 14 is connected to the control unit 14, whether the power-off is enabled or disabled is determined by the operation of the control unit 14.

FIG. 4b shows an example of the configuration of the power-off lock control unit 14, in which 15 is the central processing unit of the data processing device, 7 is the address bus of the central processing unit, 8 is the data bus, and 9 is the central processing unit that uses data. Signal line for reading (IOR...I/O READ), 1
Similarly, 0 is a signal line (IOW...I/O WRITE) for outputting data. 11 is an instruction decoder, which connects address bus 7 and signal line 1.
0 to decode the power-off lockset by the program and the power-off lockset command.

12 is a power-off lock set signal decoded by the decoder 11, and is connected to the set input terminal of the power-off lock flip-flop 4. Reference numeral 13 designates a reset signal for the power-off lock flip-flop 4, which is connected to the reset input terminal of the flip-flop 4. The output of the flip-flop 4 is connected to the base of a transistor 5, the collector of which is connected to a power cutoff switch 6. Therefore, the program
When the power-off lock flip-flop 4 is set, the output of the flip-flop 4 becomes 0 (low level) and the transistor 5 is turned off. Therefore, pressing down the power cutoff switch 6 connected in series with the transistor 5 is disabled, and power cutoff due to erroneous operation of the power cutoff switch 6 is prevented.

The power-off lock is released by resetting the power-off lock flip-flop 4 in response to a power-off lock reset command by a program.
Furthermore, when the system is powered on, a system reset signal is input to the clear terminal of the flip-flop 4, so the flip-flop 4 is in a reset state and the power cut-off switch 6 is enabled.

In addition, in a data processing device having a program-based power-off lock circuit as explained above,
If the CPU goes out of control and becomes uncontrollable, and if the power-off lock flip-flop that enables/disables the power-off switch is set and the program becomes uncontrollable, The function of the power off switch becomes invalid and the power cannot be turned off. Measures have been taken in case it is necessary to urgently shut off the power due to an abnormal state of the system or a fire outbreak. Conventional countermeasures of this type include turning off the power breaker or turning off the switch 20 in Figure 4a.
A switch is provided in parallel with the power cutoff switch 6, one end of which is grounded so that its operation is always valid. The switch 20 is mounted on a separate operation panel from the general operation switch that is normally operated, in order to prevent the power from being cut off due to erroneous operation.

(Problems to be solved by the invention) However, in the conventional technique shown in Fig. 4,
This requires a special dedicated switch to forcibly turn off the power in an emergency, which has the disadvantage of increasing the cost of the device and spoiling the aesthetics of the operating section. Furthermore, when the power is cut off using a breaker or the like, the breaker is often attached to the rear of the device, which has the disadvantage of poor operability.

The present invention aims to improve the above drawbacks.

(Means for Solving the Problems) The feature of the present invention to achieve the above object is that it has a manually operated power on switch and a power off switch, and the operation of the power off switch can be enabled/disabled by program control. In a power-off circuit for a data processing device equipped with a power-off lock flip-flop to control, the clear terminal of the power-off lock flip-flop receives a reset signal for resetting the system of the data processing device and an operation start switch. When pressed, an instruction signal that instructs the operation start control logic to load the operation start program after power-on is supplied via the gate, the power-off lock flip-flop is set, and pressing the power-off switch is disabled. Even if the start switch is pressed, the instruction signal is supplied to the clear terminal of the power-down lock flip-flop through the gate, resetting the power-down lock flip-flop and forcing the power-down switch to take effect. , in a power-off circuit of a data processing device that turns off the power by pressing a power-off switch and an operation start switch at the same time.

(Operation) The power cutoff switch is grounded via a switching transistor whose on/off is controlled by a flip-flop. The flip-flop is turned on/off by a program operation, and is reset by an operation start switch or a ready switch of the data processing device. Here, when the flip-flop is off, the switching transistor is on and the power-off switch is valid, but when the flip-flop is on, the switching transistor is off, so the power-off switch is invalid.

In an emergency, pressing the operation start switch or ready switch turns off the flip-flop and activates the power cutoff switch.

(Embodiment) FIG. 1 shows a program-based power-off lock control section to which the present invention is applied. Reference numeral 11 denotes an instruction decoder, which is connected to the address bus of the central processing unit built in the data processing device and decodes the power-off reset command and the power-off reset command, as explained in FIG. 4b. 12 is a power-off lock set signal decoded by the instruction decoder 11, and is connected to the set input terminal of the power-off lock flip-flop 4. 13
is a reset signal for the power-off lock flip-flop 4, and is connected to the reset input terminal of the flip-flop 4. The output of flip-flop 4 is connected to the base of transistor 5,
Its collector is connected to a power cutoff switch 6. When the power-off lock flip-flop 4 is set by the program, the flip-flop 4 becomes 0 (low level) and the transistor 5 is turned off, which disables pressing the power-off switch 6 and prevents power-off due to erroneous operation. . The power-off lock is released by resetting the power-off lock flip-flop 4 using a power-off lock reset command by a program. Furthermore, when the power to the system is turned on, the system reset signal is inputted to the clear terminal of the flip-flop 4 through the gate 24, so the flip-flop 4 is reset when the power is turned on, and the power-off switch is enabled.

By the way, data processing devices generally start operating after the power is turned on by
It has a switch called (Initial Program Loader). In FIG. 1, reference numeral 20 indicates an operation start switch, and when the switch is pressed, the operation start control section logic 22 is operated and the system program is loaded.

According to the present invention, one end of the operation start switch 20 is input to the gate 24 together with a reset signal, and the flip-flop 4 is reset by the output of the gate 24. Therefore, according to the present invention, once the system is activated, the lock flip-flop 4 is turned off.
is set and pressing the power off switch is disabled (power off is locked), operation start switch 2
0 is pressed, a reset signal is inputted to the clear input terminal of the power-off lock flip-flop 4 through the gate 24, and the flip-flop 4 is reset. Therefore, even when the power is turned off, the operator can turn off the power by pressing down the power cutoff switch 6 and the operation start switch 20 at the same time. Note that when the operation start switch is pressed, the system is reset to the initial state, so it is usually installed in a location where it cannot be easily operated due to erroneous operation.

Fig. 2 shows an example of mounting and mounting an operation start switch, in which 30 is the data processing device main body, 3 is a power on switch, 6 is a power off switch, and 32 is a box with a cover, in which the operation start switch is installed. Switches such as 20 that should not be pressed down by mistake during normal operation are housed.

Therefore, in normal operating conditions, the operation start switch is protected by the cover, which prevents the power-off lock from being released by a simple operation by the operator.

Although the above has described an embodiment in which a power-off lock is released by an operation start (IPL) switch, according to the present invention, any switch that sends out a reset signal to reset a power-off lock flip-flop can be used. Any switch for any purpose can be used, and a ready switch for resetting the system can also function in the same way.

(Effects of the invention) As explained above, according to the invention, even when a data processing device is in operation and the power-off switch of the device is disabled by the power-off lock circuit (the power-off lock is in effect), emergency situations, etc. If you want to immediately turn off the power to the device, press the operation start switch (IPL, etc.) and power-off switch of the device at the same time to release the power-off lock.
Further, since a dedicated switch and wiring for releasing the power-off lock are not required, costs can be reduced compared to the conventional method. Furthermore, since a dedicated switch is not required, the appearance of the operating section can be expected to be kept intact.

[Brief explanation of the drawing]

FIG. 1 shows a power cutoff circuit according to the present invention, FIG. 2 shows an embodiment of each switch according to the present invention, and FIGS. 3 and 4 show a conventional power cutoff device. DESCRIPTION OF SYMBOLS 1...Power supply, 2...Control unit, 3...Power supply switch, 5...Switching transistor, 6...
...Power off switch, 7...Address bus, 8...
Data bus, 9...Signal line, 10...Signal line, 11...Command decoder, 14...Power cut-off lock control section, 15...Central processing unit, 20...Operation start switch, 22...Operation start control Department logic, 24...Gate, 30...Data processing device main body, 32...Box with cover.

Claims (1)

[Claims for Utility Model Registration] A power-off lock flip-flop 4 which has a manually operated power-on switch 3 and a power-off switch 6, and which controls the validity/invalidity of the operation of the power-off switch 6 through program control. In the power cut-off circuit of the data processing device, the clear terminal of the power cut-off lock flip-flop 4 receives a reset signal for resetting the system of the data processing device, and a reset signal for resetting the system of the data processing device, as well as an operation after the power is turned on by pressing the operation start switch 20. An instruction signal instructing the operation start controller logic 22 to load the start program is supplied via the gate 24, and even if the power-off lock flip-flop 4 is set and the pressing of the power-off switch 6 is invalid,
The instruction signal caused by pressing the operation start switch 20 is supplied to the clear terminal of the power-off lock flip-flop 4 through the gate 24, the power-off lock flip-flop 4 is reset, and the power-off switch 6 is forcibly turned on. 1. A power cutoff circuit for a data processing device, characterized in that the power is turned off by simultaneously pressing a power cutoff switch 6 and an operation start switch 20.