JPH04143998A - Data write method - Google Patents

Abstract

PURPOSE:To double the count value of a counter by using a storage element EEPROM as the counter which counts the number of times, and using negative logic in which 1 and 0 of ordinary positive logic are inverted as number of times data to be written. CONSTITUTION:Data of all '1' is written on the EEPROM in initialization processing. The number of times data is read out from the storage element EEPROM, and one is subtracted from the number of times data, and the number of times data after subtraction is written on the storage element EEPRM again. Thence, in the output processing of the number of times data, the number of times data is read out from the storage element EEPROM, and processing in which data of negative logic is converted to data of positive logic is performed. In such a way, the number of times of write of the data of negative logic goes to around 32,000 when the EEPROM element whose service life is limited to 16,000 times of write of the data of positive logic, which doubles the service life.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Field of Application] The present invention relates to a memory element EEPRO used as a counter.
The present invention relates to a method of writing data to an electrically erasable program read-only memory (M).

[Prior Art] In many conventional devices, a counter is implemented using an electronic storage element instead of a mechanical counter. For example, in a printing device, it is necessary to count the number of sheets of printing paper, the number of rotations of a drum, etc., and store these counted values in a counter.

Furthermore, the counting data such as the total number of printing sheets generally needs to be stored even when the power of the apparatus is turned off. Therefore, B and B have conventionally been used as electronic storage elements when it is necessary to store this counting data.

M (battery pack, memory with upgrade) has been used, but in recent years EEP, which is a rewritable non-volatile memory, has been used.
ROM (Electrically Erasable ROM) is increasingly being used.

The reason for this is that EEPROM has the characteristic that once - degree data is written, the written data is saved even if no power is supplied afterwards.B,B.

This is because it has the convenience of not requiring a backup battery like the X.

FIG. 2 is a flowchart showing the counting procedure of a conventional EEPROM counter, and FIG. 3 is a diagram illustrating the number of counts of conventional positive logic.

To explain the counting method of the positive logic shown in FIG. 3, all "0"s are first written to initialize the EEPROM as a counter, and the count number is set to "0".

After that, each time the number of times is counted by one, the value obtained by adding 1 to the counter is used as the counted value of the number of times. This positive logic counting method is generally widely adopted because it is compatible with human senses (for example, the sense of adding 1 each time the number of times increases by one in solo panning).

The counting procedure of a conventional EEPROM counter will be explained with reference to FIG.

In step S21, positive logic count data (count data based on the positive logic counting method shown in FIG. 3) is read from the storage element EEPROM used as a counter.

In step S22, 1 is added to the positive logic count data read from the EEPROM to update the count data.

In step S23, the storage element EEPl? Write the updated positive logic count data to OM.

By repeating the above process every time the number of times is counted by one, it is possible to programmatically implement an EEPROM instead of a counter circuit constituted by a flip-flop or the like.

[Problems to be Solved by the Invention] However, when an EEPROM is used as a storage element for a counter, there is a limit to the number of times data can be written to the EEPROM, and the number of erasing and writing times according to the manufacturer's catalog is generally 1. The limit is Garo. For this reason, there is a problem in that the number of times that can be counted is extremely reduced compared to the case where B, B, and M are used, which have no limit on the number of times of writing.

For example, B is a 1-word (16-bit) counter.

If it is made of a memory element with no lifespan such as B or M, the capacity of the counter is 65, which is the number obtained by subtracting 1 from 2 to the 16th power.
It can count up to 535, but if it was made with EEPROM, there was a problem that it would be limited to about 16,000 counts due to the lifespan for the number of writes.

The present invention has been made to solve such problems, and uses a memory element EEP as a counter for counting the number of times.
It is an object of the present invention to provide a data writing method using a ROM that can further increase the number of counts than conventional methods.

[Means for Solving the Problems] A data writing method according to the present invention uses a storage element EEPl? as a counter for counting the number of times. Using the OM, data writing means writes negative logic number data, which is an inversion of "1" and 0" in normal positive logic, as the number data to be written into the EEPROM.

Further, in the data writing method according to the present invention, the memory element E
EPRO)! When reading and outputting the negative logic count data written in the negative logic, the data conversion means converts the negative logic count data into positive logic count data and outputs the converted count data.

[Effect] The invention works as follows.

First, in the present invention, a memory element EEPROM is used as a counter for counting the number of times. This is EEP
This is convenient because a backup power source is not required when the device is powered off after data has been written to the ROM. Then, the data writing means reads the EEPR.
As the number of times data to be written to OM, number data of negative logic, which is an inversion of "1' and "0" in normal positive logic, is written.

Is this the memory element EEPI? Each bit of memory in OM is
Each memory element E is composed of a unit called a cell, and due to the characteristic of the element that writing a ``1'' than writing a 0 consumes less charge, the memory element E
When writing data to EPROM, first write all “0”
It is better to write all “1” than to write “1” in EEPR.
This will extend the life of the OM with respect to the number of writes.

Further, in the present invention, when reading and outputting the negative logic count data written in the storage element EEPROM, the data conversion means converts the negative logic count data into positive logic count data and outputs the converted count data. . This conversion is possible by inverting each bit of the count data using negative logic such that ``12'' becomes ``0'' and '0'' becomes ``1'', which is easy to understand for humans. can be easily obtained.

[Example code] First, the rationale of the present invention will be explained.

(1) First, when writing data to the storage element EEPROM, the present invention writes all "11" as an initial value instead of writing all "0". This means that each bit of the memory of the EEPROM is a unit called a cell. It consists of
Due to the characteristic of the element that writing “1” consumes less charge in the cell than writing “0°”,
This is because writing "1°" into an EEPROM is better than writing "0" because when the EEPROM is used as a counter, the life of the element in terms of the number of writes will be extended.In other words, a counter with a long life can be obtained. This is because it will be done.

(2) Next, according to the present invention, by using a negative logic counting method, the number of times '11' is written to the upper bits of the counter is greatly increased. That is, according to the counting method of positive logic, for example, the 15th bit b15 in FIG. 3 is 0.
“0” is written every time from the 18383rd time,
Finally, "1" is written for the 18,384th time or more. By replacing this with a negative logic counting method, this “0”
The data “1” will be inverted.

FIG. 4 is a diagram illustrating the number of times the negative logic is counted according to the present invention. In the figure, "1" is written to the 15th bit b15 every time from the Oth time to the 18383rd time, and 1638 times.
“0” is finally written the fourth time or more. Also 1
“1°” is written to the 6th bit b16 every time from the 0th time to the 32767th time.

By adopting this negative logic counting method, the number of times "1" is written to the upper bit of the counter increases significantly, which causes the EEP
Due to the element characteristics of the ROM, the life of the number of writes to the element can be extended, resulting in an increase in the number of times the EEPROM can be counted as a counter. Of course, when outputting negative logic count data, converting it to positive logic and outputting it allows the operator to easily understand the count. (This conversion method will be described later.) FIG. 1 is a flowchart showing a counting procedure of a counter using an EEPROM of the present invention, and the flowchart of the same figure will be explained below.

In step S1, the negative logic count data shown in FIG. 4 is read from the storage element EEPROM used as a counter.

In step S2, processing for converting negative logic data into positive logic is performed. In the conversion process in this embodiment, positive logic data is obtained by inverting each bit of negative logic data from "1" to "Om" and from "0#" to "1°." As another conversion process, Positive logic data is obtained by performing an exclusive OR operation of negative logic data and all "1°" data.

In step S3, 1 is added to the converted positive logic data to update the count data.

In step S4, the positive logic data is again converted into negative logic data. This conversion is the same conversion as the conversion in step S2.

In other words, for each bit of positive logic data, "0" becomes "1", "
1" can be converted to negative logic data by converting it to "0". Alternatively, an exclusive OR operation similar to step S2 may be performed.

In step S5, the converted negative logic data is written into the storage element EEPROM.

By repeating the above processing every time the number of times is counted by one, the operation as a counter can be performed by a program.

Further, as another embodiment of the present invention, the initial value for the EEPROM is all "1" (positive logic data is 6
5535) may be written, and every time the number of times is counted, -1 is processed to operate as a subtraction counter. In this case, if the negative logic data is converted into positive logic data when outputting the data, it can be used as normal positive logic count data.

5(a) to 5(C) are flowcharts showing other counting procedures of the counter using the EEPROM of the present invention;
) shows the initialization process of the number data, (b) shows the counting process of the number data, and (C) shows the output process of the number data.

In the initialization process of FIG. 5(a), step Sl
All “1” in l (65535 positive logic data
) data is written to EEPROM.

In the counting process of the number of times data in FIG. 5(b), step S
In L2, the number of times data is read from the storage element EEPROM, in step 513, 1 is subtracted from the number of times data, and in step S14, the number of times data after the subtraction is written into the storage element EEPROM again.

In the output process of the number of times data in FIG. 5(C), step S
At step 15, the number of times data is read from the storage element EEPROM, and at step 516, processing for converting negative logic data into positive logic data is performed.

This conversion process is the same as the conversion process in step S2 in FIG.

Writing negative logic data in the present invention to EEPROM,
Regarding the number of writes when used as a counter,
Strictly speaking, it depends on the characteristics of the element, but according to the results of experiments with commercially available elements, the number of times positive logic data is written is approximately 1.
In the case of an EEPROM element whose life span is 8,000 times, a life span of about 32,000 times was obtained based on the number of times negative logic data was written. In other words, the life of the element is doubled. This means that the upper bit of the counter is always “0”.
This can be said to be a great effect of the present invention, which has changed from the conventional method of writing "1" to the method of always writing "1".

Further, although the above embodiment shows an example in which an EEPROM is used as a counter, the present invention is not limited to this.

For example, EEP black text or image data on a white background.
As it is stored in ROM, “0” data is more “1” than “0” data.
The present invention can be applied to the case where more data than '' is stored in the EEPROM.

When writing data to and reading data from EEPROM, if the data is inverted from "0" to "1" and from '1' to "0#", the same character or image data as before can be obtained. can be used to double the number of writes to an EEPROM device.

[Effects of the Invention] As described above, according to the present invention, the memory element EEPROM is used as a counter for counting the number of times, and the EEPROM
l? As the number of times data to be written to OM, the number of times data based on negative logic, which is an inversion of 1 and 0 in normal positive logic, is written, so EEPl? The number of counts of a counter using an OM element can be doubled.

Further, according to the present invention, the memory element EEPl? When reading and outputting the negative logic count data written in the OM, the negative logic count data is converted to positive logic count data and output, so the positive logic is easy to understand as a human sense. Data is easily obtained.

[Brief explanation of drawings]

FIG. 1 is a flow chart showing the counting procedure of a counter using the EEPROM of the present invention, and FIG. 2 is a flowchart showing the counting procedure of a counter using the EEPROM of the present invention. A flowchart showing the counting procedure of the counter by OM, FIG. 3 is a diagram explaining the conventional positive logic counting number, FIG. 4 is a diagram explaining the negative logic counting number of the present invention, and FIG. 5 (a) ( c) is a flowchart showing another counting procedure of the counter using the EEPROM of the present invention.

Claims (2)

[Claims] (1) Memory element E as a counter for counting the number of times
A data writing method using an EPROM and writing the number data of negative logic, which is an inversion of 1 and 0 in normal positive logic, as the number data to be written into the EEPROM. (2) Data writing according to claim 1, wherein when reading and outputting the negative logic count data written in the memory element EEPROM, the negative logic count data is converted to positive logic count data and output. Method.