JPS62151909A - Battery backup control circuit - Google Patents

Abstract

PURPOSE:To allow a power source circuit to execute two types of initialization processings without making said circuit complicated by initializing a backup target device only if an effective signal is not outputted when a commercial power source developing power failure is restored. CONSTITUTION:At the time of the power failure of the commercial power source 50 (a power failure period T), a power unit 20 stops supplying a DC power source. However, a battery backup unit BBU 30 continues supplying the DC power source. When the commercial power source is restored, the power unit 20 begins to supply the power source. In correspondence to the restoration, a system controller 11 initializes each device. However, this time the effective signal (BBUE) 31 is active, and the controller 11 does not initialize a main memory device (MMU)13. When an effective trigger signal (BBUS) 32 from the system control part 11 comes to a low level 0, the effective signal (BBUE) 31 is triggered to come to a high level 1, and the backup function of the battery backup unit 30 acts normally.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a battery backup control circuit for electronic equipment that is required to perform backup during a power outage.

[Conventional technology]

In electronic devices that operate manually using commercial power (AC power), the quality of the power supply has a large effect on the operation of the system.

When seeking a highly reliable system, W
Backup DC power supply (,
A mechanism is used that has means for supplying DC power (DC power) and ensures stable operation.

One widely used method is a battery backup method in which a battery is used to store a certain amount of power and DC power is supplied from the battery only during a power outage of the commercial power source. For example, in a so-called information processing system,
This battery backup is used only for some system components rather than for the entire system. This makes it possible to achieve the same functionality at a lower cost than backing up the entire system.

In such a system, when a power outage occurs and commercial power is restored (restored), it is necessary to know which device was backed up and to maintain that device. That is, in an information processing system, the main storage device is normally backed up. When the power is restored, other components such as the central processing unit (CPU) are initialized and are in the same state as when the power is turned on normally. On the other hand, the contents of data and the like stored in the main storage device must be maintained as they were in the state immediately before the power outage. As a result, the system can quickly return to the same state as it was just before the power outage occurred, and can immediately go into operation.

On the other hand, when the system is normally powered on for the first time, all components including the main storage device need to be initialized.

Since these two cases exist, the system must be aware of which case it is in and perform initialization operations depending on each case.

Conventionally, two methods have been considered as recognition means for this case.

The first method is a method in which the device being backed up τ itself provides an identification signal. Alternatively, an identification signal indicating that backup is in progress is stored in a part of the system control device (which may belong to CPIJ or may be defined as a separate unit) that starts up and initializes the system. This is a method to have a circuit with However, in the former case, it is necessary to install certain hardware in each device being backed up, and to add a circuit for reading the identification signal before initialization.

In the latter case, it is also necessary to back up part of the system control device.

This requires two power supply systems to be incorporated into the same logical device, leading to increased hardware complexity.

The second method is to prepare two switches, turn on the first input instruction switch (main switch), then turn on the second switch indicating that the backup state is healthy.
This switch is used to display the backup status. This method has a problem in restoring power when the battery is completely discharged and cannot be backed up due to a long power outage.

[Problem that the invention seeks to solve]

In this way, with conventional methods, it is necessary to create complex relationships between the backup target device and other devices, as well as between the normal power source and the backup power source, which complicates the circuit and makes the circuit design difficult. There were some difficulties, such as difficulty in

The present invention has been made with attention to the above points, and an object of the present invention is to provide a battery backup control circuit that enables two types of initialization processing for a backup target device without complicating the power supply circuit. It is something to do.

[Means for solving problems]

The battery backup control circuit of the present invention includes a main switch, a power unit that is activated by the main switch, converts commercial power to DC power, and outputs the DC power.
Similarly, a battery backup unit has a backup function that is activated by the main switch, stores a certain amount of power, and automatically outputs DC power in the event of a power outage of the commercial power supply, and is supplied with DC power from the power unit, and a system control device that controls a system including a device to be backed up and initializes the system, wherein during a power outage of the commercial power supply, the battery backup unit supplies DC power only to the device to be backed up, and This backup unit outputs a valid signal to the system control device when activated by the main switch and the backup function is normally performed, and the system control device outputs a valid signal to the system control device when the backup function is normally performed. The invention is characterized in that, when a power outage occurs and the power is restored thereafter, the backup target device is initialized only when the valid signal is not output.

[Effect]

According to this method, when the system is activated by the main switch and the battery backup unit is performing the backup function, even if a power outage occurs in the commercial power supply, the output of DC power to the backup target device does not stop. After that, when the power is restored, the system control device does not initialize the backup target device.

Here, the battery backup unit outputs a valid signal when it is performing the backup function.

When this valid signal is being output, the system control device does not initialize the backup target device, and operates to initialize the backup target device only when the valid signal is not being output. Therefore, the backup target device is initialized when activated by the main switch.

This makes it possible to completely separate the power supplies, such as supplying DC power from the battery backup unit to components that need to be backed up, and supplying DC power from the power unit to components that do not require backup.

〔Example〕

(Description of Blocks) FIG. 1 is a block diagram showing an embodiment of the battery backup control circuit of the present invention.

This circuit includes an information processing system 10, a power unit 20 that supplies DC power to the information processing system 10, a battery backup unit 30, and a main switch 40 that starts these.

The power knee unit 20 and the battery backup unit 30 are both circuits that convert the commercial power source 50 into DC power and output it to each part of the system 10, respectively.

In the system 10, a system control device 11, three logical devices 12, and a main storage device 13 are connected to each other via a system bus.
The configuration is such that they are connected via 4. Although various system components are further connected to this system 10, only the above-mentioned components are shown for convenience of explanation.

Here, the main storage device 13 is a device that performs battery backup during a power outage of the commercial power source 50, and is referred to as a backup target device in the present invention.

Other devices, that is, the system control device 11 and the logic device 12, do not receive DC power during a power outage.

Therefore, the main storage device 13 is connected to receive DC power from the battery backup unit 30, and the other devices are connected to receive DC power from the power unit 20.

Further, when the battery backup unit 30 is exhibiting a backup function, a valid signal 31 is output from the battery backup unit 30 to the system control device 11, and the system control device 11 outputs the valid signal 31 to the system control device 11. A valid trigger signal 32 for raising the signal is manually wired.

- The power unit 20 is a well-known so-called AC-D that steps down and rectifies the commercial power supply 50 to obtain a DC power supply of a predetermined voltage.
It consists of a C converter.

An example of the wiring of the battery backup unit 30 is shown in FIG.

This circuit is an AC-DC converter that steps down and rectifies the commercial power supply 50.
In this circuit, a battery 34 is connected in parallel to the output end of the converter 33, and the output thereof is further converted into a DC power source of a predetermined voltage using a DC-DC converter 35. A switch circuit 36 operated by a relay 36a is inserted on the output side of this circuit, and is further connected so that its output voltage 37 is input to a valid signal processing circuit 38 for outputting the valid signal 31. There is. The above power unit 20
A similar switch circuit (not shown) is also inserted on the output side. All switch circuits are controlled on and off by the main switch 40.

FIG. 3 shows an example of wiring of the effective signal processing circuit 38.

This is a known flip-flop circuit composed of two NAND circuits 38a and 38b, and the output voltage 37 of the battery backup unit 30 (Fig. 2) is connected to the input terminal (converted to TTL level if necessary). and a valid trigger signal 32, and a valid signal 31 is taken out from the output terminal.

The function of this circuit will be explained in detail later.

FIG. 4 shows a detailed wiring diagram around the system control device 11 of the system 10.

The system control device 11 includes a processor l having a built-in memory etc. that stores a program for initializing the system.
la is provided, where the valid signal 31 is manually applied,
Further, it is connected so that a valid trigger signal 32 is output. The processor lla and the main storage device 13 are connected to each other so as to exchange data through a system bus 14.

(Operation of the circuit) FIG. 5 is a timing chart of the operation of the circuit of the present invention. The operation will be explained with reference to this.

Turning on power to the entire system by an operator or other means is started by turning on the main switch (SW) 40. When the main switch (SW) 40 is turned on, the switch circuits 38 (Fig. 2) provided in the power unit (PU) 20 and battery backup unit (BBU) 30 are turned on, and each rectifies the human-powered commercial power source. Supplies DC power to each part of the system. In this case, the power is turned on normally. Figure 5a shows the state of the main switch 40, and figures 5, 5 and 5e indicate the power unit (
PU) 20 and battery backup unit) (BBU)
30 output states are shown.

Initially, the valid signal (BBUE) 31 (FIG. 1) is set to inactive (FIG. 5a).

The system control device 11 (Fig. 1) is a power unit).
DC power is supplied from the (PU) 20 to initialize each device. In this embodiment, each logical device 12 is reset through the system bus 14 while the main memory (MMU)
) 13, processing is performed to write reset data to all of its addresses.

Before initializing the main memory 13, the system controller 11 checks the valid signal 31 and, if active, does not initialize the main memory 13. If it is inactive, its initialization is performed. In this normal power-on, as described above, the valid signal (BBUE) 31 is inactive, so the main storage device 13 is initialized.

After receiving a valid signal (BBUE) 31, the system control device 11 outputs a valid trigger signal (BBUS) 32 (
Figure 5C). battery backup unit) (BBU
) 30 receives this and activates the enable signal 31 (FIG. 5d).

During a power outage of the commercial power supply 50 (power outage period T in Figure 5), the power unit 20 stops supplying DC power, but the battery backup unit (BBU) 30 continues to supply DC power (Figure 5). e).

When the power is restored, the power unit 20 starts supplying power again (
Figure 5b).

In response to this, the system control device 11 initializes each device, but this time the main memory unit (MMU) 13 is not initialized because the valid signal (BBUE) 31 is active.

In the valid signal processing port 38 of FIG. 3, when the main switch 40 (FIG. 1) is off, the output voltage 37 of the battery backup unit 30 is at low level "0", and the valid trigger signal (BBU'5) 32 is high level 11
It is 111. As a result, the valid signal (BBUE) 31 is at low level "0".The system control unit 11 (
When the valid trigger signal (BBUS) 32 from FIG.
is triggered and becomes a high level "'1", indicating that the backup function of the batch backup unit 30 is operating normally. This is as explained in FIG. 5 c1d. (Figure), all DC power supply is stopped and the output voltage 37 of the battery backup unit 30 is also at a low level.
It becomes O”.

This causes the valid signal (BBUE) 31 to return to inactive.

In this way, according to the above embodiment, two DC power supply systems are provided, and the supply route from the power unit and the supply route from the battery backup unit are completely separated, and power is supplied to only the minimum number of components in the event of a power outage. It can be configured as follows.

Here, in the device of the present invention, the system control device determines whether or not to initialize the backup target device in accordance with the valid signal output from the battery backup unit.

If the battery backup unit is to output a signal for this initialization determination, special consideration must be given to the hardware of both the power supply line from the power unit and the power supply line from the battery backup unit. There's no need. Therefore, the degree of freedom in design is increased and the configuration is simplified. Further, there is no need to provide a special circuit in the backup target device.

[Modified example]

The battery backup control circuit of the present invention is not limited to the above embodiments.

The configuration of the system may be such that various components other than the upper side are added. Further, this can be applied not only to information processing systems but also to various circuits that require battery backup in part.

Further, the circuit configuration of the battery backup unit may be replaced with various circuits having similar functions. Regarding the output timing of the valid signal and its contents,
Feel free to make changes as you see fit.

〔Effect of the invention〕

The battery backup control circuit of the present invention described above can supply two systems of mutually independent DC power supplies to the system, one of which can be used for backup. Furthermore, different initialization methods can be used for initial startup and for power recovery after a power outage.

[Brief explanation of drawings]

Fig. 1 is a block diagram showing an embodiment of the battery backup control circuit of the present invention, Fig. 2 is a detailed wiring diagram of the backup unit, Fig. 3 is a wiring diagram of the effective signal processing circuit, and Fig. 4 is a detailed wiring diagram of the backup unit. The figure is a peripheral wiring diagram of the system control device, and FIG. 5 is a timing chart illustrating the operation of the battery backup control circuit of the present invention. 10...System, 11...System control device, 13...Backup target device, 20...
...Power unit, 30...Battery backup unit, 40
...Main switch, 50...Commercial power supply. Applicant NEC Corporation Representative Patent Attorney Umeo Yamauchi Figure 1

Claims (1)

[Claims] a main switch, a power unit that is activated by the main switch, converts commercial power to DC power and outputs it; and a power unit that is also activated by the main switch,
A battery backup unit having a backup function that stores a certain amount of power and automatically outputs DC power in the event of a power outage of the commercial power supply, and a system that is supplied with DC power from the power unit and that controls a system that includes a device to be backed up. and a system control device that initializes the system by using the system controller, wherein when the commercial power supply is out of service, the battery backup unit supplies DC power only to the backup target device; When the main switch activates the backup function and the backup function is normally performed, a valid signal is output to the control device, and the system control device . A backup control circuit, wherein the backup control circuit initializes the backup target device only when the valid signal is not output.