JPS5891599A - Storage controlling system - Google Patents

Abstract

PURPOSE:To easily cope with a temporary voltage drop, by providing a means for checking an error of a data read out from a storage device, when switching the storage device to a back-up battery at the time of disconnection of an electric power supply, and detecting a voltage drop of the battery. CONSTITUTION:When a back-up battery 2 is turned on at the time of disconection of an electric power supply, a controlling circuit 5 operates, a storage device supplies an address signal, a storage address is driven in order, and a stored data is read out in order. In case when stored contents have been broken down due to an operating voltage drop, a parity checking circuit 11 automatically checks whether it is a pairty error or not, at the time of read-out operation. When an error is detected by the parity checking circuit, an alarm is raised from the controlling circuit 5, the operation is discontinued, and the stored contents are corrected. In this way, a voltage drop is detected easily.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention provides storage devices with
In the case of switching, the voltage drop of the IE source is simply detected and the storage control method is involved.

Conventionally, in an eccentric system with a storage device, even when the power is turned off,
In order to retain the memory contents, a method is used in which a backup battery is provided and switched. FIG. 1 shows a dead battery detection method in this case.

That is, the power supply circuit 1 and battery 2 are supplied to the switching storage circuit 4 by the power supply switching circuit 5. When the Lumi source is turned on, the power supply switching circuit 3 supplies power from the power supply #A circuit 1 to the storage device 4,
When the power is turned off, power from the battery 2 is supplied to the storage device 114 to retain the stored contents. In this case, if the voltage of the battery 2 becomes less than the operating voltage of the storage device 4, the stored contents may be destroyed, so it is detected that the voltage of the battery 2 becomes less than the operating voltage of the storage device 4. There is a need. For this purpose, a reference voltage circuit 6 is provided that generates a voltage corresponding to the operating voltage of the storage device 4, and a voltage comparison circuit 7 compares this reference voltage with the voltage of the battery 2, and sends the result to the voltage comparison circuit 5. It monitors the battery voltage and generates an alarm when it detects that the battery voltage has dropped to the reference voltage. This method of comparing with a reference voltage has the problem that the multiple circuits that require the reference voltage are complicated, and when a charging circuit is connected to the battery, the detection of a drop in the Ka voltage becomes static.

SUMMARY OF THE INVENTION An object of the present invention is to provide a simple and reliable storage control method for detecting a voltage drop in a backup power supply.

In order to achieve the above object, the storage control method of the present invention has a control circuit that operates according to the stored contents of the storage device, and in order to retain the storage contents when the power supply to the storage device is cut off, the storage control method of the present invention has a control circuit that operates according to the stored contents of the storage device. In the power supply method, the control circuit includes means for checking the lu of data successively outputted from the storage device, and the control circuit switches the power supply by reading data from the running time storage device when the power supply is turned on. It is designed to detect a voltage drop in the backup power supply at 70 lk.

The apparatus will be described in detail below with reference to examples.

Figure H2 is a configuration explanatory diagram of an embodiment of the present invention.

As shown in the figure, the present invention does not use a method of comparing the battery voltage with a reference voltage, but simply checks the contents of the storage device when the device is powered on, and checks the nv
If sn is not present, the device will operate normally. In other words, if the power is turned on or the control circuit 5
operates, the memory device 4 supplies an address area, and sequentially increments the memory addresses to sequentially read out the data stored in each address. The parity check circuit 11 automatically checks whether there is a parity error during the read operation if some of the storage elements of the storage device 4 are destroyed due to a drop in operating voltage. Since the battery voltage decreases gradually and the operating voltage decrease characteristics of the memory elements vary, it is very effective to be able to rescue most of the p by early detection.

This can be thought of in the same way as the detection of destruction of memory contents due to noise during an attack. The control circuit 5 is the storage device 4
Even if data is continuously output from the address area allocated to
If the alarm signal is not supplied to the parity check circuit 11, the control circuit 5 assumes that there is no failure in the battery 2 and operates normally. The parity check may be performed on the stored contents horizontally, vertically, or both, and may be performed on all or part of the stored contents. When an error is detected in the parity check circuit 11, the control circuit 5 also generates an alarm, and as a result, the operation is interrupted and the stored contents are corrected. However, depending on the memory contents, there may be cases where it is not desirable to interrupt the process.

No. s! IA is an explanatory diagram of another embodiment of the present invention used in such a case, and has 6 stones. That is, when the memory devices 41 e 4 m having different operating voltages are connected and the device is powered on, the control circuit 5 continuously operates the memory devices 41 e 4 m.

4mK The same address signal is given to output stored data one after another.

- By checking the parity of the memory device 43 with a higher operating voltage in the same way as shown in FIG. 2, it is possible to completely prevent the omission of the memory IFO due to the failure of the memory device 14s with a lower operating voltage. .

Iris 4E line It is a configuration explanatory diagram of another embodiment of the bottle of the present invention. In contrast to the above-mentioned embodiment, which checks data errors in the memory contents of the storage device by checking the data errors, the data errors in the memory contents of the storage device are checked using a parity checker. In other words, as shown in Figure PI1, a formatter circuit 12 is provided and an alarm is generated from the control circuit 5 in the event of a format error, as in the case of Figure 2. The check circuit can also be used in conjunction with a parity check circuit.

As described above, according to the present invention, when a storage device is switched to a backup battery when the power is turned off, a voltage drop in the battery is detected by parity or format checking to detect data errors in the storage contents of the storage device. It is. This simplifies the battery dead detection circuit and allows it to detect temporary voltage drops (when the voltage is restored to normal when the power is turned on).

[Brief Description of the Drawings] Fig. 1 is an explanatory diagram of the configuration of a conventional example, lI & 2IiA is an explanatory diagram of the configuration of an embodiment of the present invention,! Figure I3 and Figure 4 are configuration explanatory diagrams of other embodiments of the present invention, respectively.In the figures, 1 is a power supply circuit, 2 is a battery, 5 is a power supply switching circuit, 4°41g4m
5 is a storage device, 5 is a control circuit, 11 is a retail check circuit, and 12 is a photo check circuit.

Claims (1)

[Claims] It has a control circuit that operates according to the contents stored in the storage device,
A method of supplying power to a storage device from a backup power source in order to retain the memory contents when the power supply to the storage device is cut off.
At Pln, a means for checking the power of data successively output from the storage device is provided, and the control circuit outputs data continuously from the running time storage device when the power supply is turned on and switches the power supply #l for the battery up. A memory control method that detects voltage drops.