JPS6310463B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (a) Technical Field The present invention relates to a power-off processing device for electronic equipment that saves various processing data to a battery-backed-up memory when a power-off is detected.

(b) Prior art and its disadvantages In order to prevent data from being destroyed due to a power interruption such as a momentary power outage, generally when a power interruption is detected, the processed data at that time is stored in a battery backed-up memory. It is necessary to save the data, but conventional power-off processing devices simply shift the CPU to data save processing mode when a power-off is detected. Therefore, if the time from when the input power is turned off until the internal voltage drops and the CPU stops operating is extremely short, data will not be saved correctly, but even in such cases, when the power is restored, The drawback was that the CPU continued processing assuming that the saved data was correct.

(c) Purpose of the Invention The purpose of the present invention is to monitor the time from when the power is shut off until the CPU stops operating using a counter, thereby making it possible to check whether the data at the time of the power shutoff has been accurately saved when the power is restored. To provide a power-off processing device for electronic equipment, which allows an operator to easily determine whether saved data is reliable or not by displaying it externally.

(d) Structure and Effects of the Invention To summarize, the present invention can be summarized as follows:
a counter that counts until the operation stops, a count value writing means that writes the count value of the counter to a battery backed-up memory every time a count is made, and a count value that reads the count value stored in the memory when the power is restored; and a data evacuation reliability display means for displaying the reliability of data evacuation according to the value of the count value, and a counter counts the time from when the power is cut off until the CPU substantially stops operating, When the power is restored, it is determined whether the counted value exceeds a predetermined value and a display indicating the degree of reliability is displayed.

(e) Embodiment FIG. 1 is a block diagram of a power-off processing device which is an embodiment of the present invention.

In the figure, a and b are power input terminals, and the power supply 1 generates an operating voltage based on the power input during normal times. CPU2, memory 3, I/
O4 and other circuit elements are operated by the voltage generated by the power supply 1, and the memory 3 retains stored data by the battery E when the voltage falls below the operating threshold. The comparator 5 detects the interruption of the power supply voltage, and outputs a power interruption signal to the CPU 2 when the power interruption is detected. Lamps LA, LB, and LC are connected to I/O4, and when the power is restored, one of the lamps is turned on based on the output of CPU2.

Next, the operation of the power-off processing device will be described with reference to FIG.

First, when comparator 5 detects power interruption, the CPU
A power cutoff signal is sent to 2, and the operation mode is shifted to the power cutoff processing mode. When CPU2 moves to this mode, it first goes to step n1 (hereinafter referred to as step ni).
is simply called ni. ), the necessary processing data at that time is saved to a predetermined area of the battery backed up memory 3. The time required to save this data is usually several milliseconds. After the CPU 2 finishes saving the data, it then sets the power supply holding counter C allocated within the CPU to 1 at n2. Further, the contents of counter C are set in area MA of memory 3, n3, and then counter C is incremented, and n3 is executed again. CPU2 is this n3,
The operation of n4 is continued until the voltage supplied from the power supply 1 becomes below the operating threshold.

Next, when the power is restored, the CPU 2 executes the power restoration mode. First, in n5, the data set in area MA of memory 3 is read out, and then in n6, that area MA is cleared in preparation for the next power cutoff. Next read area
Determine whether the data of MA is 0 or not n7,
If it is not 0, further determine whether the data is less than a certain value N set in advance.
8. And if the above data is 0, then n
At step 9, a lamp LC is lit to indicate that data saving is incomplete, and when the above data is less than N, a lamp is lit at step n10 to indicate that data has been saved but power retention time is insufficient.
Turn on LB. Further, when the data is equal to or greater than N, a lamp LA is turned on at n11 to indicate that the data has been completely saved. Therefore, when the lamp LC is on, the operator knows that the job that was running before the power was cut off needs to be restarted from the beginning, and when the lamp LA is on, the operator knows that the job that was running before the power is cut off must be restarted from the beginning. It is possible to recognize that the job that was being executed can be continued after the power is restored. When the lamp LB is lit, it is determined whether the job needs to be restarted from the beginning or whether it can be continued, depending on the importance of the job being executed.

Since any of the lamps LA to LC is lit in this manner, the operator can make an appropriate selection regarding the CPU job after power is restored.

(f) Effects of the Invention As described above, according to the present invention, a counter counts the time until the CPU stops operating after a power cut is detected, and the counted value is stored in a battery backed-up memory. However, when the power is restored, the count value is read out and the reliability of the saved data is displayed, so it is easy to determine whether the data has been saved correctly when the power is restored. It is possible to appropriately judge whether the job that was being executed before the power was shut off can be continued or whether the job that was being executed before the power was shut off needs to be executed again from the beginning. As a result, the job that was in use before the power was shut off may continue to be executed after the power is restored even though the data has not been correctly evacuated, or the job that was before the power was shut off may continue to be executed after the power is restored even though the data has been evacuated correctly. This has the advantage that the CPU operates more efficiently when the power is restored, without having to execute the job from scratch.

[Brief explanation of the drawing]

FIG. 1 is a block diagram of a power-off processing device according to an embodiment of the present invention, and FIG. 2 is a flowchart showing the operation of the same processing device. 1...Power supply, 5...Comparator (for power cutoff detection).

Claims (1)

[Scope of Claims] 1. In a power-off processing device for an electronic device that saves various processing data to a battery-backed-up memory when a power-off is detected, counting is performed until the operation of a CPU stops after a power-off is detected. a counter; a count value writing means for writing the count value of the counter to the memory for each count;
When power is cut off for an electronic device, the device is equipped with a data save reliability display means for reading out the count value stored in the memory when the power is restored, and displaying the degree of data save reliability according to the value of the count value. Processing equipment.