JPS58108932A - Battery backup device - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention performs battery backup K11I of a semiconductor memory device (volatile memory).

In semiconductor storage devices, it is necessary to protect the stored contents in the event of an abnormality in the power supply IIO (temporary power outage).In this case, as a method of preserving the stored contents, a battery is generally added to provide a backup function. Figure 1 shows such a device in block diagram form.In Figure 6, it is %(1)'VicPU (including power supply),
2) is a semiconductor storage device (volatile memory); (3)
#DC power supply device with battery for fi-batter-up,
(4) ti A C input, (5) is the DC power supply voltage, (
6) is a data signal path. The backup time depends on the battery capacity and the current consumption of the storage device. Generally speaking, it is not possible to increase the capacity of the battery due to limitations such as installation, system space, etc., and the backup time is shortened. Furthermore, when a long-term power outage occurs, the battery continues to be discharged until its remaining capacity reaches OAK, resulting in a shortened battery life.

The present invention has been made in view of the above, and it is an object of the present invention to provide a battery backup device capable of retaining the memory contents of a semiconductor storage device for a long time with a small capacity battery. ' The details will be explained below using examples. FIG. 2 is a plotter diagram showing one embodiment of the present invention.

In this figure, the same reference numerals are given to the same functional parts as in FIG. 1. The feature in Fig. 2 is that non-volatile memory (7) such as a magnetic disk or floppy disk is stored as a semiconductor memory value
2a) Connect using the GC data transfer path line (8). +9) is a signal that transmits the stored data to the Cg source device (3a) with battery backup when the semiconductor storage device completes data transfer to the nonvolatile t-memory (7) through the pass line (8). (3
11) has a function of cutting off the color's DC output 15) when it receives this signal.

Next, the timing chart of the operation shown in FIG. 2 is a!
This will be explained using Figure 3. When the AC input (4) is supplied, the power inside the CPU is turned on, the CPU issues a DC power-on command, and the DC power supply voltage (5) is generated by AC-DC conversion from the DC power supply (3a).

Due to the generation of DC power supply voltage (5), the semiconductor memory device (2 m
) receives the stored contents of the non-volatile memory (7) via the data transfer bus (%8). This transfer time varies depending on storage capacity. Non-volatile memory 13 in semiconductor storage device (2a)
('7) is completed, the semiconductor storage device ('7) is transferred.
3) accepts requests from the JIU (1) and other devices (not shown) via the signal bus (6);
The contents are read from the semiconductor storage device (2a) or written to the semiconductor storage device (2a) [execution period: trout in FIG. 3]. Therefore, the access speed for requests from the CPU (1) and other devices (not shown) is faster than non-volatile memory (1) such as magnetic disks and floppy disks.
Direct access to ) 41 improvements.

When the AC input is cut off, the CPU (1) or power supply (3a) detects the condition and outputs the DC power supply voltage (5) with battery backup to data the memory contents of the semiconductor storage device (2a). Transfer to the non-volatile memory (7) is started via the transfer bus (8). When the transfer is completed, the semiconductor storage device t(21) is transferred from the power supply device [(3a
)5 A power cutoff signal (9) is sent to cut off the DC power supply voltage output (5) of the power supply device (3a).

As can be seen from the above, the discharge current of the battery in the busy power supply device (3m) starts with cutting off the tiAc input, and the semiconductor storage device (2a)
) is completed upon completion of transferring the stored contents to the nonvolatile memory (7). Therefore, the capacity of the battery is determined by the current consumption and transfer time of the semiconductor storage device (21) and the nonvolatile memory (). When the system C input is restored, the same operation as when the DC power-on command was issued is performed.

As described above, the present invention is a Klkb device, and since the capacity of the backup battery is sufficient to operate from the cutoff of the C input to the completion of the data transfer, it is sufficient that the present invention is relatively small and has a long life. The memory contents are retained even if the input of the memory is interrupted over time. First, non-volatile memory is AC
Since the transfer with the semiconductor memory device is performed only when the input 1a is turned off, a high speed is not required.

In addition, even with a battery of the same capacity, the remaining capacity of the battery is large even in the event of a power outage during president's time (it reaches 70 to 80 degrees), so it can have the effect of extending the life of the battery. .

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing a conventional battery backup device, and FIG. 2 is a block diagram showing an embodiment of the present invention.
Figure 3 shows the operation timing of Figure 2. Lightning 821...Volatile memory (semiconductor storage device) 3Jl...DC power supply device
4...Ac cuff...Non-volatile memory agent Patent attorney Inoue-Male

Claims (1)

[Claims] From non-volatile memory to volatile memory when AC input is ON,
AC input 0FFliK Two memories that mutually transfer data from volatile memory to nonvolatile memory, and AC
It is equipped with a DC power supply device equipped with a battery to back up the KDC power supply when the input is OFF, and the AC input is OFF (
A battery backup device characterized in that the supply of DCiIIIEIII from a battery that has been turned on is turned off upon completion of data transfer from a volatile memory to a nonvolatile memory that started at 0FPK of the AC input.