JPH0266797A - Nonvolatile memory write processing method - Google Patents

Abstract

PURPOSE:To increase the using efficiency of a write area by comparing write data with read data whenever writing is executed to a prescribed bank, judging that the life of the bank is expired at the time of discordance, and using the next tank. CONSTITUTION:First, the data are written by using a first bank out of the plural banks formed in a nonvolatile memory (EEPROM) 9, whenever the writing is executed, the data in an address are read, they are compared with the write data, when they are discordant, the first bank is judged to be expired, and the wall written data are shifted to the second bank, the data writing is executed by using the second bank from the next time, and thereafter the same processing as above is repeated. Thus, since the respective plural banks can be used until their lives are expired, the EEPROM 9 having the restriction of the number of times of rewriting can be efficiently used for a long time.

Description

DETAILED DESCRIPTION OF THE INVENTION <Industrial Application Field> The present invention relates to a method for writing data into a rewritable non-volatile memory.

<Conventional technology> EEFROM and NOVRAM (SRAM and EEFRO)
Rewritable non-volatile memory, such as those with a dual structure of have. Therefore, conventionally, non-volatile memory is
It is installed in various devices and used to store specific data that should be saved.

For example, in facsimile machines, EEROM is used to store communication result data (Japanese Unexamined Patent Application Publication No. 1983-1999-1).
(See Publication No. 88961).

In addition, selectable printer settings such as font type, character pitch, number of lines on a page, etc. need to be retained even when the device is powered off, so these settings are stored in non-volatile memory. It is often done.

Non-volatile memories are also used to store data in so-called electronic notebooks and desktop electronic computers.

<Problems to be Solved by the Invention> Data cannot be permanently rewritten in such nonvolatile memory any number of times, and there is generally a limit to the number of times that data can be rewritten. For example, in the case of EEPROM, it is said that each bit is normally processed about 10,000 times.

Therefore, if the data in non-volatile memory is frequently rewritten, the limit number of times it can be rewritten may be exceeded without you noticing, and the memory may become unusable, causing problems such as equipment malfunction. Conceivable.

Therefore, it is an object of the present invention to provide a write processing method for efficiently using non-volatile memory, and also to provide a memory write processing method that prevents non-volatile memory from becoming unusable unnoticed. With the goal.

Means for Solving the Problems> The present invention is a write processing method for writing data to a nonvolatile memory, which comprises forming a plurality of first to nth banks in a write area of the nonvolatile memory. , Out of the multiple banks, first use the first bank to write data, and each time you write, read the data in the written address and compare it with the written data, and when the two are no longer the same, It is determined that the life of that bank has expired, all data written in the first bank is moved to the second bank, and the next data write is performed using the second bank in the same way as in the previous case. This is a write processing method for a non-volatile memory, characterized in that data is written while checking the written data each time a write is performed, and data is written up to the n-th bank by repeating the same process thereafter.

Function> A plurality of banks are formed in the write area depending on the storage capacity and purpose of use of the nonvolatile memory. Then, data is written using the first bank, and each time data is written, the written data is read and compared with the written data. If the two are the same, that bank is used continuously, and if they are the same, then the data is written. If the current bank is judged to have reached the end of its lifespan, the bank in which data is to be written is switched to the next bank.

Thereby, the writing area can be used efficiently.

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

FIG. 3 is a block diagram showing the configuration of a link control circuit provided with an embodiment of the present invention.

The control circuit of this printer uses C as the center of control processing.
A reception buffer 3, a program memory 4, a font memory 5, a page buffer 6, a bitmap memory 7, a work memory 8,
A non-volatile memory 9, a switch 10 of the operation section, a display device 11 of the operation section, an output buffer 12, etc. are connected.

When data is provided from a host device such as a workstation via the host interface 13 and reception buffer 3, the CPUI subjects the data to predetermined processing. In order to carry out this process, a predetermined program is stored in the program memory 4 configured with a ROM. In addition, a plurality of fonts are stored in a font memory 5 composed of a ROM so that printing can be performed in various fonts. A page buffer 6 composed of a RAM is used to store data for each page to be printed out. A bitmap 7 and work memory 8 made up of RAM are also provided and are utilized during processing.

In this embodiment, the non-volatile memory 9 is composed of an EEPROM, and the EEPROM 9 stores information such as the type of font,
Data that should be retained even when the device power is turned off, such as character pitch, number of lines on one page, and other print formats, is stored.

A switch 10 of the operation section is used to give a power on/off signal, an operation start command, a paper feed signal, and other signals to the printer. The display device 11 of the operation section is for displaying predetermined contents to be notified to the operator.

The output signal is applied to an output circuit 14 via an output buffer 12, and an engine of a printer (not shown) is driven.

FIG. 2 is an illustrative diagram showing the configuration of the EEPROM 9 described above. This EEPROM9 has 8 bits x 8K (=8
It has a storage capacity of 2 bytes).

Incidentally, in order to store the print format and other setting data that should be retained even when the power is turned off in the printer described above, a memory storage capacity of 2 bytes is usually sufficient. Therefore, in this embodiment, EEP
The ROM 9 is divided into four banks of two bytes each, ie, a first bank, a second bank, a third bank, and a fourth bank, and the banks are used in the order from the first bank to the fourth bank.

FIG. 1 is a flowchart showing a procedure for writing data into the memory of FIG. Next, the data write processing method of this embodiment will be explained with reference to FIGS. 1 and 2.

The starting address As of the EEPROM 9 is initialized to address 0 (step Sl).

When there is a request to write data D to any address A of the EEPROM 9 (step S2), it is written to A s of the first bank.
Address 10A (However, in the first bank, As
=O. ) (step S3).

Then, the written data D is read out (step S4), and the read data D' is compared with the written data D (step S5). If data D is written correctly, D==D'.

In step S5, write data D and read data D
', the control returns to step S2 and waits for the next data write request.In step S5, if the write data D and the subsequent data D' are different, the control returns to step S2 and waits for the next data write request. Since the data was not written correctly to the address As+A, it can be estimated that the number of times the data at that address has been rewritten has exceeded the possible number of rewrites, that is, approximately 10,000 times. Therefore, in that case, the entire area of the first bank, that is, from address As to As+
The contents stored up to address 7FF are moved from address As+800 to address As+FFF, which constitutes the second bank (step S6). Then, set the first address As to 800.
As the address (step S7), control returns to step S2.

Similarly, every time data D is written to the second bank, the written data is read and the written data D and read data D' are compared. If the two do not match,
Switching to data writing using the next third bank, and then switching to the fourth bank.

As a result, if there is a part of a bank that has reached the end of its data rewriting lifespan, that bank will be discontinued and data will be written using a new bank. can be used until the end of its life.

In this embodiment, the EEPROM 9 is divided into four banks, but an appropriate number may be selected depending on the storage capacity of the entire nonvolatile memory and the purpose of use.

In addition, in this way of using EEPROM9,
When writing data to the fourth bank, if it is determined that there is a mismatch between the write data D and the read data D', the EEP
The display on the operation panel (the third
It is preferable to display the information as shown in the figure (see figure). Then, maintenance of the device or replacement of the EEPROM 9 can be performed based on the information.

<Effects of the Invention> Since the present invention is configured as described above, it is possible to efficiently use a nonvolatile memory whose number of rewrites is limited for a long period of time.

This method is particularly effective when the data rewriting frequency within the bank is random for each area, and it is possible to reliably detect if there is an area within the bank that has reached the end of its life first. Based on this, equipment maintenance and EEP
Able to handle ROM9.

[Brief explanation of the drawing]

FIG. 1 is a flowchart showing a procedure for writing data to an EEPROM 9 according to an embodiment of the present invention. FIG. 2 is an illustrative diagram showing the configuration of the EEPROM 9 according to an embodiment of the present invention. FIG. 3 is a block diagram of a control circuit of a printer employing an embodiment of the present invention. In the figure, 9...EEPROM (non-volatile memory) is shown.

Claims (1)

[Claims] 1. To write data to non-volatile memory A write processing method, The first area in the write area of non-volatile memory forming a plurality of banks, First, select the first bank among multiple banks. Write data using The data in the written address is Read the data and compare it with the written data, When the two are no longer the same, the band After determining that the service life of the All data written to the Move to 2nd bank, For subsequent data writing, use the second bank. As in the previous case, write using Check the written data every time you Go empty-handed, By repeating the same process Data will be written up to the nth bank. A non-volatile material that is characterized by Mori's writing process method.