JP3335210B2 - Counter - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

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

[0002]

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

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

In order to prevent such a phenomenon, for example, it is conceivable to provide a backup of the power supply to guarantee the time of continuous data writing, but in this case, the operation of the microcomputer or the like must also be guaranteed. The load is heavy and requires a fairly large capacity. If such a large capacity is secured, problems such as safety at the time of OFF (a live line remains for a long time), a rise time at the time of power-on, and an inrush current occur.

[0005]

As described above, when a plurality of data are continuously written as a counting device,
If the power is turned off during the writing, for example, there occurs a problem that the first data has been rewritten to a new one, but the next data remains old, and the data is unreliable. To prevent this, if a large-capacity power supply backup is ensured to guarantee continuous data writing time, safety during power-off (long live lines remain), 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 supply backup and that ensures data reliability.

[0006]

According to the present invention, a counting device 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. Updating means for updating the numerical values of the respective management areas provided in the lower area and the upper area when the successive numerical values carry from the lower area to the upper area; and the respective management areas updated by the updating means. Writing means for writing the numerical value of the area and the value counted by the counting means into the storage means; reading means for reading the numerical values of a plurality of areas stored in the storage means at a predetermined timing; And comparing means for comparing numerical values of the management area provided in the upper area and the lower area in the plurality of areas read by the means.

[0007] A counting device according to the present invention comprises a counting means for counting continuous numerical values, a storing means for storing numerical values counted by the counting means in a plurality of areas, and an area for each area stored in the storing means. Update means for providing a management area and updating the numerical values of the respective management areas provided in the lower area and the upper area when the continuous numerical value counted by the counting means carries from the lower area to the upper area; Writing means for writing the numerical value of each management area updated by the updating means and the numerical value counted by the counting means into the storage means; and writing the numerical values of the plurality of areas stored in the storage means to a predetermined value. Reading means for reading at a timing; and comparing means for comparing numerical values of management areas provided in an upper area and a lower area in a plurality of areas read by the reading means. As a result of the comparison by the comparing means, when there is a mismatch, a correcting means for correcting the numerical value of the upper area or the lower area and the numerical value of the management area, and a numerical value of the area corrected by the correcting means and a numerical value of the managing area. And a rewriting means for rewriting the numerical value of the corrected area and the numerical value of the management area stored in the storage means.

[0008]

According to the present invention, continuous numerical values are counted by a counting means, the counted numerical values are stored in a plurality of areas of a storage means, and a management area is provided for each of the stored areas.
When the continuous numerical value counted by the counting means carries from the lower area to the upper area, the numerical value of each management area provided in the lower area and the upper area is updated, and the numerical value of each updated management area is updated. And the numerical value counted by the counting means are written in the storage means, and the numerical values of the plurality of areas stored in the storing means are read out at a predetermined timing. This is to compare the numerical values of the provided management areas.

[0009]

An embodiment of the present invention will be described below with reference to the drawings.

FIG. 1 shows a serial EEPROM as a copy number counter of an electronic copying machine to which the counting device of the present invention is applied.
This shows a case where M is used. That is, the copy number counter of the electronic copying machine includes a microcomputer 1 for controlling the equipment, and an EEPR for writing and reading data.
OM2, connected to the power supply terminal of EEPROM2,
It comprises a capacitor 3 for backing up the power supply 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 a serial port of the microcomputer 1 for controlling equipment 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, so that even if the entire power supply is turned off during the data write operation, the power supply of the EEPROM 2 is backed up for a time until the write operation is completed.

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

Therefore, this counter data cannot be stored in one storage unit (16 bits = approximately 64000), so that it is arranged over two areas.

For example, as shown in FIG. 2A, a description will be given of a case where the upper three digits and the lower three digits are stored in separate upper area and lower area, respectively, as shown in FIG. I do. (Each counts 000-999)

The copy number counter constituted by the EEPROM 2 is counted up by the microcomputer 1 every time one copy is performed.
As long as data is written in the lower area in the range of 0 to 998, there is no change in the upper area, and only the lower area needs to store data.

Now, when the counter value changes from "999" to "1000", that is, when a carry occurs from the lower digit to the upper digit, the data is updated in both the upper and lower areas. They need to be written together.

In FIG. 2A, for example, assuming that writing starts from the lower area and then writes to the upper area,
When the operation is normal, first, the lower area is written from “999” to “000”, and then the upper area is written “00”.
"001" is written from "0" and the counter value is "00".
1000 ".

However, starting writing from the lower area,
If the power is turned off during the write operation of this lower area,
Writing to the upper area is not 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 value of the counter becomes "000000", which deviates from the normal value by 1000.

To prevent such a phenomenon, it is conceivable to make the backup of the power supply longer as described above. In this case, however, the operation of the microcomputer 1 must be guaranteed, and a considerably large capacity is required. And
(Note: After a write command is issued, the serial EEPROM will continue to operate even if the microcomputer stops operating. However, the power of the EEPROM itself must be supplied. When such a large capacity is provided, problems such as safety when the power is turned off, rise time when the power is turned on, and inrush current occur as side effects.
Therefore, in the present invention, a carry management area is provided in the data to secure the reliability of the data and eliminate the need for a large-capacity power supply backup.

In FIG. 2B, the EEP of this embodiment is shown.
Since the ROM 2 only needs to store a 3-digit numerical value in a 16-bit area, even if a BCD (binary-coded decimal code) is used, a 4-bit area is left, and this 4-bit area is used as a carry management area. Usually, the same data is written in both 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, the lower order digit of the EEPROM 2 is counted up by "+1" by the microcomputer 1 each time one copy is performed. When the lower digit becomes “999” and carry is performed, the management area of the lower digit and the upper digit is counted up by “+1”. That is, the lower area is written from "0999" to "1000" including the management area, and the upper area is written "000" including the management area.
"1001" is written from "0", and the value of the counter becomes "001000" excluding the management area.

However, starting writing from the lower area,
If the power is turned off during the write operation of this lower area,
Writing to the upper area is not executed. That is, the lower areas include “0999” to “10” including the management area.
After "00" is written, the power is turned off and the upper area including the management area is not written and remains at "0000".

The value of the counter at this point is “000000” as in the above case, but for the management area, the lower digit is “1” and the upper digit is “0”, and there is a mismatch between the upper digit and the lower digit. It has become. Based on the discrepancy between the numerical values in the management area, it is determined that the power has been turned off during writing.

At the next power-on, the microcomputer 1
Compares the numerical values of the upper digit / lower digit management area, and determines that a carry has occurred if the numerical values of the upper digit / lower digit do not match.

When 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 the upper digit management area by "+1". That is, the upper area is written from “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 this embodiment, the writing operation is performed each time the count of the number of copies is performed. However, the present invention can be applied to, for example, writing at the end of copying. In this case, it is conceivable that two or more carry occurs, but the difference between the value of the management area of the upper digit and the lower digit is “2”.
If so, carry is performed twice, and if "3", carry is carried out three times, so that the reliability of the data described above can be ensured. In addition, the present invention is not limited to counting the number of copies, and can be applied to, for example, handling of continuous numerical values such as toner consumption and lamp life.

As described above, according to the above embodiment,
If you want to store consecutive numbers in multiple areas,
By providing a carry management area in the data, even if the writing operation is interrupted halfway, it can be corrected later to ensure the reliability of the data.

[0028]

As described in detail above, according to the present invention,
A counting device that does not require a large-capacity power supply backup and that ensures data reliability can be provided.

[Brief description of the 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 from power-on.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Microcomputer 2 ... EEPROM 3 ... Condenser 4 ... Scan motor 5, 7 ... Driver 6 ... Main motor

────────────────────────────────────────────────── ─── Continuation of the front page (56) References JP-A-51-84565 (JP, A) JP-A-63-299612 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) H03K 21/40 G06F 7/00

Claims (4)

(57) [Claims] 1. A counting means for counting continuous numerical values, a storing means for storing numerical values counted by the counting means in a plurality of areas, and a management area for each area stored in the storing means. Updating means for updating the numerical values of the respective management areas provided in the lower area and the upper area when the continuous numerical values counted by the counting means carry from the lower area to the upper area; Writing means for writing the numerical value of each management area and the numerical value counted by the counting means into the storage means; and reading out the numerical values of the plurality of areas stored in the storage means at a predetermined timing. Means, and comparing means for comparing 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. 2. The apparatus according to claim 1, wherein said reading means reads numerical values of a plurality of areas stored in said storage means in synchronization with power being supplied to said 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. Updating means for updating the numerical values of the respective management areas provided in the lower area and the upper area when the continuous numerical values counted by the counting means carry from the lower area to the upper area; Writing means for writing the numerical value of each management area and the numerical value counted by the counting means into the storage means; and reading out the numerical values of the plurality of areas stored in the storage means at a predetermined timing. Means for comparing numerical values of management areas provided in an upper area and a lower area in a plurality of areas read by the reading means; As a result of the comparison, if they do not match, the correcting means for correcting the numerical value of the upper area or the lower area and the numerical value of the management area; and the storing means by using the numerical value of the area corrected by the correcting means and the numerical value of the management area. Rewriting means for rewriting the numerical value of the corrected area and the numerical value of the management area stored in the counter. 4. The apparatus according to claim 3, wherein said reading means reads numerical values of a plurality of areas stored in said storage means in synchronization with supply of power to said counting device. Counting device.