JPH0387911A - Power supply controller - Google Patents

Abstract

PURPOSE:To prevent the occurrence of such a fault as a system starting operation is made impossible by cutting off a power supply after finishing a writing process to a file device with an interruption incapable of the mask control. CONSTITUTION:When the cut-off of a power supply part 7 is instructed by a power supply ON/OFF switch 8, just an interruption signal incapable of the mask control is outputted to a control part 1 of a microcomputer and the supply of power is not immediately stopped to the microcomputer. The part 1 receives the interruption signal and finishes a writing job as long as the data are being written into a file device 6. Then the part 1 outputs a power supply cut-off signal to the part 7, and the part 7 receives this signal and stops the supply of power for the first time. As a result, the data are surely assured within the device 6 when an operator cuts off the power supply at an optional time point. Thus it is possible to prevent such a case where a system is not started when a power supply is applied again.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a power supply control device for a microcomputer.

(Prior Art) A microcomputer generally operates by receiving power from a predetermined power source, processes various types of information, and stores the processed information.

FIG. 2 is a block diagram showing the configuration of a conventional microcomputer system.

The illustrated system includes a control section 11, a file device 2, a power supply section 13, an AC input plug 14, and a power on/off switch 15.

The control unit 11 includes a main processor, a main memory, and the like. The main processor then performs processing such as reading information from the file device 12 into the main memory, processing the information on the main memory, and writing the information to the file device 12, for example.

The file device 12 is, for example, an external storage device such as a magnetic disk device.

The power supply unit 13 includes a rectifier circuit and the like, converts the commercial frequency AC power input from the AC input plug 14 into DC power, and supplies the DC power to the control unit 11 and the file device 12.

The AC plug plug 14 is for connecting the power supply unit 13 to an outlet that supplies power from a power line or the like.

The power on/off switch 15 is separated from the on/off switch and is used to electrically connect and disconnect the AC input plug 14 and the power supply unit 13.

Next, the operation of the above-described device will be explained.

When the operator presses the power on/off switch 15, AC power is supplied from the AC input plug 14 to the power supply section 13 via the power on/off switch 1. The power supply section 13 rectifies alternating current into direct current, and supplies direct current power to the control section 11 and the file device 12. As a result, the microcomputer system starts up and the file device 12
The information stored in is processed. Processing is completed,
When the power on/off switch 15 is turned off, the supply of DC power from the power supply unit 13 is stopped. This causes the microcomputer system to stop.

(Problems to be Solved by the Invention) However, the above-described device has the following problems.

That is, while writing information to the file device 12,
When the power on/off switch 15 is turned off, the information written to the file device 12 is no longer guaranteed.

FIG. 3 is a time chart showing the state of writing data to the file device 12.

As shown in the figure, data 1 to 1 are stored in the file device 12.
If the power is turned off at time 1+ while data is being written in the order of 3, the contents of the data (
(the shaded area shown) will not be guaranteed.

Furthermore, if the data written to the file device 12 is information for controlling the file device 12, normal information will not be read even if the power on/off switch 15 is pressed again next time. This caused the problem that the microcomputer system would not start up.

Furthermore, the length of the data shown in FIG. 3 is not necessarily a fixed length and may be unpredictable.

Therefore, it is not possible to provide a backup power source that reliably guarantees that all data written to the file device 12 is written normally when the power on/off switch 15 is turned off.

Another possible method is to turn off the power on/off switch 15 after the operator confirms that all data writing processing has been completed using a screen such as a CRT or a man-machine interface. However, such a method cannot reliably prevent the operator from accidentally turning off the power on/off switch 15.

Furthermore, a method is provided in which a flag indicating that the power on/off switch 15 is turned off is provided in the software, and a predetermined program is used to determine this flag and turn off the power.
It is also conceivable that when the power on/off switch 15 is turned off, a predetermined program performs an interrupt process to turn off the power. However, if such a predetermined program has a low priority, the process may have to wait indefinitely, and there is a problem that the power may not be turned off for an indefinite period of time.

The present invention has been made with attention to the above points, and when an operator turns off the power at any time when controlling the power of a microcomputer, the data in the file device is reliably protected and the power is turned off. It is an object of the present invention to provide a power supply control device that prevents a situation in which a system cannot start up when the system is turned on again.

(Means for Solving the Problems) A power supply control device of the present invention is a device for controlling a power supply section of a microcomputer equipped with a file device, and includes a switch for instructing turning on and off of the power supply section, and a power supply control device using the switch. When a disconnection instruction is received, an interrupt circuit outputs an interrupt signal (NMI) that cannot be masked to the control section of the microcomputer, and an interrupt signal is input from the interrupt circuit to perform write processing to the file device. The power supply section includes a file control section and a power cutoff circuit that outputs a power cutoff signal for cutting off the power after the write processing by the file control section is completed, and the power supply section is configured to turn off the power when the power supply cutoff signal is input. It is characterized by cutting.

(Function) In the above-described device, when the switch instructs the power supply section to be turned off, an interrupt signal that cannot be masked is output to the control section of the microcomputer, but the power supply to the microcomputer is not immediately stopped. . If data is being written to the file device upon reception of the interrupt signal, the control section of the microcomputer completes the writing. Thereafter, the control section of the microcomputer outputs a power-off signal to the power supply section.

The power supply section stops supplying power only after receiving this power cutoff signal.

(Embodiment) FIG. 1 is a block diagram showing the configuration of a microcomputer system equipped with a power supply control device of the present invention.

The illustrated system includes a control section 1, a main processor 2, a file control section 3, a file device 6, a power supply section 7, a power on/off switch 8, an AC input plug 9, and the like.

The control section 1 includes a main processor 2 and a file system J section 3.
and a main memory (not shown).

The main processor 2 includes a file control section 3 and a power supply section 7.
, and processing data read out from the file device 6 to the main memory by the file control unit 3. Inside the main processor 2, a power cutoff circuit 2a is provided. The main processor 2 also receives an interrupt signal 4 from the power supply unit 7 that cannot be masked.
The input constitutes a write processing unit that completes the write process to the file device 6.

After receiving the non-maskable interrupt signal (NMI) 4 from the power supply unit 7 and completing the data writing process to the file device 6, the power supply cutoff circuit 2a transmits a message to the power supply unit 7.
It outputs a power cut signal 5.

The file control unit 3 controls reading and writing of the file device 6 according to instructions from the main processor 2.

The file device 6 is an external storage device consisting of a magnetic disk or the like.

The power supply section 7 is equipped with a rectifier circuit, and has an AC input plug 9.
This is for rectifying the alternating current supplied through the converter into direct current.

FIG. 4 is a block diagram showing details of the power supply section 7 of FIG. 1.

As illustrated, the power supply section 7 includes a main power supply section 71, a state control section 72, an on/off control section 73, a switch power section 74, and a sub power supply section 75.

The main power supply section 71 includes a rectifier circuit and the like, and rectifies the alternating current supplied from the AC input plug 9 into direct current, and supplies the direct current to each section of the microcomputer.

The state control section 72 is for maintaining the state of the main power supply section 71 in an on state or an off state. The state control section 72 is controlled to switch from an off state to an on state by an output signal from an on/off control section 73, and from an on state to an off state by a power cutoff signal 5 from a control section 1.

The on/off control section 73 outputs an output signal to the state control section 72 or an interrupt signal (NMI) 4 that cannot be masked, depending on the output signal from the switch input section 74.

Interrupt signals used in microcomputers include interrupt signals that can be masked and interrupt signals that cannot be masked. A normal interrupt signal is an interrupt signal that can be masked. An interrupt signal that can be masked is one in which the interrupt request can be ignored by masking the interrupt signal.

Interrupt signals that cannot be masked are those that accept interrupts without being affected by interrupt masks or interrupt prohibition instructions, and are called NMI (Non Maskable Indicators).
turrupt).

The switch input section 74 is connected to the power supply changeover switch 8 , and outputs a signal to the on/off control section 73 according to the input state of the power supply changeover switch 8 .

The sub-power supply section 75 consists of a low-power rectifier circuit, etc., and includes a state control section 72, an on/off control section 73, and a switch input section 7.
Supply power to each of 4.

The power supply on/off switch 8 is constituted by a non-lock type switch. That is, this power on/off switch 8
consists of a movable contact 8a and fixed contacts 8b and 8c, and the movable contact 8a is normally maintained in contact with the fixed contact 8b. In this state, the power on/off switch 8 is in the off state. Then, when the power on/off switch 8 is turned on, the movable contact 8a is changed to the fixed contact 8 by the operator.
It is turned on only while it is pressed to the C side.

The AC input plug 9 is for connecting a commercial frequency AC power source to the main power supply section 71 and the sub power supply section 75, respectively.

Next, the operation of the microcomputer configured as described above will be explained.

First, the AC input plug 9 connects the power supply section 7 to an AC power source. When the power on/off switch 8 shown in FIG. 4 is pressed down, the movable contact 8a and fixed contact 8c of the non-locking switch are brought into contact. As a result, an output signal is output from the on/off control section 73 to the state control section 72 in response to an instruction from the switch input section 74 . By this output signal, the state control section 72 is switched from the off state to the on state, and the main power supply section 71 is turned on. As a result, rectification is started in the main power supply unit 71, and DC power is supplied to the control unit l and the file device 6 that constitute the microcomputer. Thereafter, the program stored in the file device 6 is read out by the control section 1, and the data stored in the file device 6 is processed.

When such processing is completed, the operator presses the power on/off switch 8 again to bring the movable contact 8a and the fixed contact 8C into contact. In this case, pressing the power on/off switch 8 while the power supply unit 7 is activated is determined to be an instruction to turn off the power. Then, the power supply unit 7 outputs an interrupt signal (NMI) 4 that cannot be masked to the main processor 2.

When the main processor 2 receives this interrupt signal 4, if the file device 6 is in the process of writing data, it ends the writing. That is, the main processor 2 outputs the interrupt signal 4 at time t shown in FIG.
When data 2 or data 3 is received, data 2 or data 3 is transferred to file device 6.
Terminates the process of writing to. The time t when this process ends
2 or t3, the power cutoff circuit 2a of the main processor 2
outputs a power-off signal 5. This power cutoff signal 5 switches the state of the state control section 72 shown in FIG. 4 from the on state to the off state. As a result, the main power supply section 71 is turned off and the microcomputer is stopped.

As described above, even if the power on/off switch 8 is pressed by mistake while the main processor 2 is writing data to the file device 6 via the file control unit 3, the main processor 2 There is no interruption in writing data to. Therefore, data in the file device 6 can be prevented from being destroyed. Further, the termination process in the main processor 2 is performed with the highest priority by an interrupt signal 4 that cannot be masked. Therefore, the termination process is not made to wait due to other processes, and the main power supply unit 71 is reliably turned off after the power on/off switch 8 instructs the power off.

Note that the present invention is not limited to the embodiments described above.

That is, for example, in the embodiment described above, the file device 6 is a magnetic disk, but it goes without saying that it may be other storage devices such as a magnetic tape or a semiconductor memory. Further, although the power on/off switch 8 is a non-lock type switch, it can also be configured with a normal open/close type switch.

(Effects of the Invention) As explained above, according to the power supply control device of the present invention,
The power is turned off after the process of terminating the write process to the file device by an interrupt that cannot be masked, resulting in the following effects.

In other words, if the operator accidentally turns off the power,
It is possible to prevent the writing process from being interrupted in the middle of writing data to the file device. Therefore, the data in the file device is reliably guaranteed, and it is possible to prevent failures such as the inability to start up the system. Furthermore, since the interrupt is not affected by other factors, it is possible to reliably complete the write process and then turn off the power.

[Brief explanation of drawings]

FIG. 1 is a block diagram showing the configuration of a microcomputer system equipped with a power supply control device of the present invention, FIG. 2 is a block diagram showing the configuration of a microcomputer system equipped with a conventional power supply control device, and FIG. 3 is a block diagram showing the configuration of a microcomputer system equipped with a conventional power supply control device. A time chart showing the state of writing data to the device, and FIG. 4 are block diagrams showing details of the power supply control device of the present invention. 1... Control unit, 2... Main processor, 3...
File control unit, 4... Interrupt signal (NMI) that cannot be masked, 5
- Power cutoff signal, 6... File device, 7-... Power supply unit, 8... Power on/off switch, 9... AC input plug.

Claims (1)

[Scope of Claim] A device for controlling a power supply section of a microcomputer equipped with a file device, comprising: a switch for instructing turning on and off of the power supply section; An interrupt circuit that outputs an interrupt signal (NMI) that cannot be masked to a control unit of a computer, a file control unit that performs write processing to a file device based on the input of the interrupt signal from the interrupt circuit, and a write process by the file control unit. and a power cutoff circuit that outputs a power cutoff signal for cutting off the power after the processing is completed, and the power supply unit cuts off the power supply upon input of the power cutoff signal. Device.