JPH06283998A - Counting device - Google Patents

Abstract

PURPOSE:To secure the reliability of data without backing up a large-capacity power source. CONSTITUTION:An EEPROM 2 is connected to the serial port of a microcomputer 1 for equipment control and a capacitor 3 is connected to the power source (Vcc) terminal of the EEPROM 2; even if the main power source is turned during writing operation for data, the power source of the EEPROM 2 is backed up only for the period of time until the wiring operation ends. Successive of copying sheets of data of an electronic copying machine are stored in plural areas of the EEPROM 2 and each area is provided with a carry control to make corrections at the time of power source input even if the power is broken on the way of the writing operation.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a counting device for counting continuous numerical values such as counter data of electronic copying machines.

[0002]

2. Description of the Related Art In a counting device in electronic equipment such as an electronic copying machine, an EEPROM is often used as a nonvolatile data memory. Above all, serial input / output EEPR
OM is often used because it has few I / O pins and is low in price.

In the serial EEPROM, when a store operation (write operation) is input, it takes some time (about 10 mS) before the next command can be accepted. Therefore, when writing multiple data continuously, if the power is turned off during writing, for example, the first data is overwritten with new data, but the next data remains old. Occurs.

In order to prevent such a phenomenon, for example, a backup of the power source may be provided to guarantee the time of continuous data writing, but in this case, the operation of the microcomputer or the like must also be guaranteed. It has a large load and requires a considerably large capacity. If such a large capacity is secured, problems such as safety at the time of off (live line remains for a long time), rise time at the time of power-on, and inrush current occur.

[0005]

As described above, when a plurality of data are continuously written as the counting device,
If the power is turned off during writing, for example, the first data is overwritten with new data, but the next data remains old, causing a problem that the data is unreliable. To prevent this, when a large-capacity power backup is secured to guarantee continuous data writing time, safety at off (live line remains for a long time), rise time at power on, inrush current There was such a problem. Therefore, an object of the present invention is to provide a counting device that does not require a large-capacity power source backup and ensures the reliability of data.

[0006]

The counting device of the present invention comprises:
A counting means for counting continuous numerical values, a storage means for storing the numerical values counted by the counting means in a plurality of areas, and a management area for each area stored in the storage means are provided. Updating means for updating the numerical values of the respective management areas provided in the lower area and the upper area when the consecutive consecutive numerical values carry from the lower area to the upper area, and the respective management areas updated by the updating means And a reading means for reading the numerical values of a plurality of areas stored in the storage means at a predetermined timing, and the reading means. It is composed of a comparison means for comparing the numerical values of the management area provided in the upper area and the lower area in the plurality of areas read by the means.

The counting device of the present invention comprises: counting means for counting continuous numerical values; storage means for storing the numerical values counted by the counting means in a plurality of areas; and for each area stored in the storage means. A management area is provided, and when the consecutive numerical values counted by the counting means carry from the lower area to the upper area, updating means for updating the numerical values of the respective management areas provided in the lower area and the upper area, and The writing means for writing the numerical values of the respective management areas updated by the updating means and the numerical values counted by the counting means into the storage means, and the numerical values of the plurality of areas stored in the storage means are set to predetermined values. A reading means for reading at a timing, and a comparing means for comparing the numerical values of the management areas provided in the upper area and the lower area in the plurality of areas read by the reading means. As a result of comparison by this comparison means, if they do not match, the correction means for correcting the numerical value of the upper area or the lower area and the numerical value of the management area, and the numerical value of the area and the numerical value of the management area corrected by this correction means And the rewriting means for rewriting the corrected area numerical value and the management area numerical value stored in the storage means.

[0008]

According to the present invention, continuous numerical values are counted by the counting means, the counted numerical values are stored in a plurality of areas of the storage means, and a management area is provided for each of the stored areas.
When the consecutive numerical values counted by the above counting means carry from the lower area to the upper area, the numerical values of the respective management areas provided in the lower area and the upper area are updated, and the updated numerical values of the respective management areas. And the numerical values counted by the counting means are written in the storage means, the numerical values of the plurality of areas stored in the storage means are read out at a predetermined timing, and the upper area and the lower area in the plurality of read areas are read. The numerical values of the management areas provided are compared.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings.

FIG. 1 shows a serial EEPRO as a copy number counter of an electronic copying machine to which the counting device of the present invention is applied.
The case where M is used is shown. That is, the copy number counter of the electronic copying machine is the microcomputer 1 for controlling the equipment, and the EEPR for writing and reading data.
EEP connected to the power supply terminals of OM2 and EEPROM2
It is composed of a capacitor 3 for backing up the power source of the ROM 2, a scan motor 4 for a reading unit (not shown), a driver 5 for driving the scan motor 4, a main motor 6 for an image forming unit (not shown), and a driver 7 for driving the main motor 6. ing.

The EEPROM 2 is connected to the serial port of the microcomputer 1 for device control and is connected so that data can be written and read. Also,
A capacitor 3 is connected to the power supply (Vcc) terminal of the EEPROM 2.
Is connected, and even if the entire power source is turned off during the data writing operation, the power source of the EEPROM 2 is backed up for the time until the writing operation is completed.

In the case of a model such as 93C46, the EEPROM 2 handles data in units of 16 bits. On the other hand, the counter of the electronic copying machine has 6 digits (0
0000-999999).

Therefore, since this counter data cannot be stored in one storage unit (16 bits = about 64000), the counter data is arranged over two areas.

For example, as shown in FIG. 2 (a), this is divided into 3 digits, and the upper 3 digits and the lower 3 digits are stored in different upper and lower areas. To do. (Counting 000 to 999 respectively)

The copy number counter composed of the EEPROM 2 is incremented by the microcomputer 1 every time one copy is made.
As long as data is written in the lower area in the range of 0 to 998, the upper area does not change and only the lower area needs to store the data.

Now, when the counter value changes from "999" to "1000", that is, when a carry from the lower digit to the upper digit occurs, the data is updated in both the upper area and the lower area. It is necessary to write together.

In FIG. 2A, for example, if writing is started from the lower area and then the upper area is written,
When operating normally, first, the lower area is written as "999" to "000", and then the upper area is written as "00".
"0" to "001" are written, and the counter value is "00".
1000 ".

However, starting writing from the lower area,
If the power is turned off during the write operation in this lower area,
Writing to the upper area will not be executed. That is, after the lower area is written from "999" to "000",
When the power is turned off and the upper digit is not written and remains "000", the counter value becomes "000000", which is 1000 deviation from the normal value.

In order to prevent such a phenomenon, it is conceivable to lengthen the backup of the power source as described above, but in this case, the operation of the microcomputer 1 must be guaranteed and a considerably large capacity is required. And
(Note: If a write command is issued to the serial EEPROM, it will continue to operate even after the microcomputer stops operating. However, the power of the EEPROM itself must be supplied. If such a large capacity is provided, side effects such as safety problems at power-off, rise time at power-on, and inrush current occur.
Therefore, according to the present invention, a carry management area is provided in the data to ensure the reliability of the data and eliminate the need for a large-capacity power source backup.

In FIG. 2B, the EEP of this embodiment
ROM2 only needs to store a 3-digit number in a 16-bit area, so even if BCD (binary coded decimal code) is used, a 4-bit area remains, and this 4-bit area is used as a carry management area. However, the same data is usually written in the upper digit management area and the lower digit management area. Next, the operation will be described with reference to the flowcharts of FIGS.

First, in the EEPROM 2, the lower digit is incremented by "+1" by the microcomputer 1 every time one copy is made. When the lower digit is “999” and a carry is carried out, the management area of the lower digit and the upper digit is incremented by “+1”. That is, the lower area is written as "0999" to "1000" including the management area, and the upper area is written as "000" including the management area.
"0" to "1001" are written, and the value of the counter is "001000" excluding the management area.

However, starting writing from the lower area,
If the power is turned off during the write operation in this lower area,
Writing to the upper area will not be executed. That is, the lower areas including the management area are from "0999" to "10".
After "00" is written, the power is turned off and the upper area including the management area remains "0000" without being written.

The value of the counter at this point is "000000" as above, but in the management area, the lower digit is "1" and the upper digit is "0", and the upper digit / lower digit do not match. Has become. It is determined that the power was turned off during writing due to the mismatch of the numerical values in the management area.

At the next power-on, the microcomputer 1
Compares the numerical values in the upper digit / lower digit management areas, and determines that there has been a carry when the numerical values in the upper digit / lower digit do not match.

When the numerical values of the upper digit and the lower digit of the management area do not match, the microcomputer 1 counts up the upper area by "+1" and further counts up the management area of the upper digit by "+1". That is, the upper area is written as "0000" to "1001" including the management area, and the counter value is "001" excluding the management area.
000 ". In this way, correct data is stored.

In the present embodiment, the writing operation is performed every time the number of copied sheets is counted, but the present invention can be applied to the case of collectively writing at the end of copying. In this case, a carry may occur more than once, but the difference between the values of the upper digit and lower digit management areas is "2".
If so, carry is carried out twice, and if it is "3", carry is carried out three times, whereby the reliability of the above-mentioned data can be secured. Further, the present invention can be applied not only to counting the number of copies, but also to handling continuous numerical values such as toner consumption and lamp life.

As described above, according to the above embodiment,
If you want to store consecutive numerical values in multiple areas,
By providing a carry management area in the data, the reliability of the data can be ensured by correcting it later even if the write operation is interrupted in the middle.

[0028]

As described above in detail, according to the present invention,
It is possible to provide a counting device that does not require large-capacity power source backup and ensures data reliability.

[Brief description of drawings]

FIG. 1 is a block diagram showing a schematic configuration of a copy number counter of an electronic copying machine according to a counting device of the present invention.

FIG. 2 is a diagram for explaining a carry of a copy number counter.

FIG. 3 is a flowchart for explaining carry of a copy number counter.

FIG. 4 is a flowchart for explaining a carry operation after the power is turned on.

[Explanation of symbols]

 1 ... Microcomputer 2 ... EEPROM 3 ... Capacitor 4 ... Scan motor 5, 7 ... Driver 6 ... Main motor

Claims (4)

[Claims] 1. A counting means for counting continuous numerical values, a storage means for storing the numerical values counted by the counting means in a plurality of areas, and a management area for each area stored in the storage means. When the consecutive numerical values counted by the counting means carry from the lower area to the upper area, the updating means for updating the numerical values of the respective management areas provided in the lower area and the upper area, and the updating means, Writing means for writing the numerical values of the respective management areas and the numerical values counted by the counting means to the storage means, and reading for reading the numerical values of the plurality of areas stored in the storage means at a predetermined timing. Means for comparing the numerical values of the management areas provided in the upper area and the lower area in the plurality of areas read by the reading means. Counting device to collect. 2. The reading means reads the numerical values of a plurality of areas stored in the storage means in synchronism with the supply of power to the counting device. Counting device. 3. A counting means for counting continuous numerical values, a storage means for storing the numerical values counted by the counting means in a plurality of areas, and a management area for each area stored in the storage means. When the consecutive numerical values counted by the counting means carry from the lower area to the upper area, the updating means for updating the numerical values of the respective management areas provided in the lower area and the upper area, and the updating means, Writing means for writing the numerical values of the respective management areas and the numerical values counted by the counting means in the storage means, and reading for reading the numerical values of the plurality of areas stored in the storage means at a predetermined timing. Means for comparing the numerical values of the management areas provided in the upper area and the lower area in the plurality of areas read by the reading means, and the comparison means As a result of the comparison, if they do not match, a correction means for correcting the numerical value of the upper area or the lower area and the numerical value of the management area, and the storage means by the numerical value of the area and the numerical value of the management area corrected by the correction means And a rewriting unit for rewriting the corrected numerical value of the area and the numerical value of the management area stored in the counting apparatus. 4. The reading means reads the numerical values of a plurality of areas stored in the storage means in synchronization with power supply to the counting device. Counting device.