JPH0266796A - Write processing method for nonvolatile memory - Google Patents

Abstract

PURPOSE:To increase the using efficiency of a write area by forming plural banks in the write area, providing the counting area of the number of times of corresponding writing, and shifting data to the next bank when a counted value amounts to a prescribed value. CONSTITUTION:First to an n-th banks are formed in the write are of a nonvolatile memory (EEPROM) 9, the counting area to count the number of times of writing corresponding to the plural banks is provided, first, the data are written by using the first bank, and the counted value in the counting area corresponding to the first bank is incremented according to the writing. Next, when the counted value in the first bank counting area amounts to the prescribed value fixed beforehand, the data written to the first bank are shifted to the second bank, thereafter the processing is repeated in the same way as above, and the data are written in the n-th bank. Thus, the EEPROM 9 having the restriction of the number of times of rewriting can be effectively used for a long time, and an unexpected unusable condition can be prevented.

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> EEPROM and NOVRAM (SRAM+EEPRO
It is said that rewritable non-volatile memory, such as those with a dual structure of It has properties. Therefore, nonvolatile memories have conventionally been included in various devices and used to store specific data that is desired to 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 a nonvolatile memory any number of times, and there is generally a limit to the number of times it can be rewritten. For example, in the case of EEFROM, each bit is usually 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, resulting in inconveniences 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 the 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. , A count area for counting the number of writes is provided in the write area of the nonvolatile memory corresponding to the plurality of banks from the first to W2B, and data is first written using the first bank among the plurality of banks. The count value of the count area corresponding to the first bank is incremented according to the writing, and when the count value of the first bank count area reaches a predetermined constant value, the data written in the first bank is incremented. is transferred to the second bank, and the next data write is performed to the second bank, and the count value of the count area corresponding to the second bank is incremented according to the write, so that the count value of the second bank count area is set in advance. When a predetermined constant value is reached, the data written in the second bank is transferred to the third bank, and the same process is repeated thereafter to write data up to the nth bank. This is a write processing method for non-volatile memory.

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 a certain bank, and when the number of data writes during the hang reaches a predetermined number, data is written using 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 pit map memory 7, a work memory 8,
A nonvolatile 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 the types of fonts,
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 the output circuit 1-4 via the output buffer 12, and the engine of the printer (not shown) is driven.

FIG. 2 is an illustrative diagram showing the configuration of the EEPROM 9 described above. This EEPROM 9 has a storage capacity of 8 bits x 8K (=8 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 above-mentioned printer, it is usually sufficient to have a memory capacity of 2 or more. Therefore, in this embodiment, EEPR
Divide OM9 into 4 banks of 2 bytes each, namely a first bank, a second bank, a third bank and a fourth bank,
Banks are used in order from the 1st bank to the 4th bank. Also, the first 16 heights of each bank are used as a count area. The count area is configured to have eight 2-byte counters.

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

The first address As of the EEPROM 9 is set to address 0 (step S1), and the contents of the count area from address As to address As+15 are cleared and initialized (step S2). Further, as will be described later, the value Cn for specifying whether to use the count area is set to Cn=0 (step S4
).

When there is a request to write data to any address A of the EEPROM 9 (step S3), it is written to As+A of the first bank.
Address (However, in the first bank, As=0 as mentioned above)
It is. ) (step S5), and the count value of address As+Cn, which is the count area, is incremented by "1" (step S6). In other words, the number of writes is counted based on the address As+Cn. In the initial state, the count value of address As Cn, which has a 1-byte (=8 bits) configuration, is r.
0OOOQOOOJ, and the value is incremented by 1 according to the number of times data is written, and finally r
11], 111.1], J to “00000000”
becomes. When this happens, carry up and increment the contents of address As+Cn+1 by "1" (step S7→
S8).

The above-mentioned count is repeated according to data writing, and As
→ -Cn+1 address count value roooll, Lll
, Jl, IF in hexadecimal notation) (step S
9) , Renew Cn+2 as Cn Step S], 0
), the operation from step S4 is repeated until Cn-16 (step S]l).

Specifically, the count area is 2 bytes (-16 bits)
Because of the configuration, if all 16 bits are used as digits, 2 = 65,536 times, which exceeds the number of rewrites of the least significant bit or the normal possible number of rewrites of 10,000 times. Therefore, 13 of the 16 bits are used, and when the count reaches 213=8,192, the counter is moved to the next 2-byte counter, and this is repeated eight times. Therefore, total 8,192X8=
65,536 counts. Here, it is said that the number of times that an EEPROM can be rewritten is usually about 10,000 times, but this is the number of times that one bit can be rewritten, and data writing in the [th bank] is performed to address As+A, and the data is The A address changes according to the
It is thought that when rewriting is performed 80,000 times, one bit will be used twice in about 10,000 times. Therefore, 6
If it is determined that the scheduled number of rewrites has been completed at 5.536 times, the number of rewrites is sufficiently within the maximum number of times that the EEPROM can be rewritten.

When the scheduled number of rewrites of the first bank is completed, the area excluding the count area of the first bank, that is, from address As+10h to address As+7FFh (note that the h after the number indicates hexadecimal representation) The stored contents are moved from address As+810h to address As+FFFh, which constitutes the second bank (step 512). Then, set the first address As to address 800h and step 81
3), the control is repeated in the same way. Then, when the number of data writes to the second bank reaches 65,536 times, the next switch is to write data to the third bank, and then to the fourth bank.

In step S12, the contents of the area other than the count area of the first bank are transferred to the second bank, or the contents of the count area of the first bank may also be transferred to the second hang. After the transfer, the count area is cleared in step S2, so there is no problem.

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 nonvolatile memory as a whole and the purpose of use.

In addition, in this method of using the EEPROM 9, when data has been written to the fourth bank a predetermined number of times, the CPU (see Figure 3) determines this and displays the display on the operation section]-1. If you display that in
Based on this information, maintenance of the device or replacement of the EEPROM 9 can be performed.

<Effects of the Invention> Since the present invention is configured as described above, a non-volatile memory whose number of rewrites is limited can be effectively used for a long period of time.

In particular, this method is particularly effective when the frequency of data rewriting within a bank is uniform, that is, when data is mostly rewritten all at once.

[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 an 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)
, not 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, The above-mentioned number is written in the write area of the non-volatile memory. Corresponding to the 1st to nth banks Count area that counts the number of writes established, The first bank among multiple banks Write data using the counter corresponding to the first bank according to the Increment the count value in the death, Count value of the first bank count area When reaches a predetermined constant value, the first bar data written in the second bank. Move to Next data will be written to the second bank. At the same time, according to the writing, the second bank The count value of the count area corresponding to the increment Count value of second bank count area When reaches a predetermined constant value, the second bar The data written in the third bank Move to By repeating the same process Write data up to the nth bank. A non-volatile memo featuring write processing method.