JP2003015942A - Method of writing data into memory, data write processing program and data write device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve write processing speed and processing efficiency and to contribute in longer life of memory. SOLUTION: Parameters to be stored in a sector n in a flash ROM are brought together in one block, and the data size SIZE of the parameter block for which the parameters are brought together in one block is calculated (step S1). Besides, in the sector n, by the processing in steps S4 to S8, a balance check is made to find whether or not a memory area has a blank area equivalent to the parameter size SIZE. In addition, if the determination result in the step 8 is NO and the blank area size is equal to or more than the parameter size SIZE, it is meant that an area, in the sector n, equivalent from an address indicated by adrs to the parameter size SIZE is in a blank state and is write enabled. In this case, thus, an address that a variable for address adrs indicates in the sector n is determined as a writing start address for the parameter (step S9).

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD OF THE INVENTION

The present invention relates to a data writing method, a data writing processing program and a data writing device for writing data in a memory such as a flash memory.

[0003]

[Prior art]

A flash memory or the like is used as a memory in which data can be freely written and read, contents can be electrically erased, and data is saved even when the power is turned off. Conventionally, data writing to this flash memory is performed in sector units, and is performed by erasing a sector in which data should be written and then writing data to the erased sector.

[0005]

[Problems to be Solved by the Invention]

As described above, if the data is erased in the sector unit at the time of writing, there is a disadvantage that the writing takes time, and the erase process is performed in the sector unit even when a parameter having a small data amount is written. This is inefficient in terms of processing. Further, since the flash memory and the like have a limited number of erasures, there is a disadvantage that the life is shortened as the rewriting frequency increases.

The present invention has been made in view of such conventional problems, and a method of writing data to a memory, which can contribute to improvement of write processing speed and processing efficiency, and extension of memory life, It is an object to provide a data writing processing program and a data writing device.

[0008]

[Means for Solving the Problems]

In order to solve the above-mentioned problems, a first aspect of the present invention is a method of writing data to a memory, wherein data in an erase unit area of the memory is sequentially read and writable. A state determination step for determining whether or not the state, and a capacity determination for determining whether or not the area determined to be writable in the state determination step is an area sufficient for writing data to be written in the memory And a data writing step of writing data in an area determined to be an area sufficient for writing data to be written in the memory in the capacity determining step.

Therefore, if it is determined that the memory is in a writable state and the determined area is an area sufficient for writing the data to be written in the memory, the data is written in the area. Therefore,
Writing can be started without erasing the memory. Therefore, the write processing speed is improved, and the write processing can be efficiently performed when a parameter having a small data amount is written. Further, it is possible to reduce the frequency of the erasing process of the memory and contribute to prolonging the life of the memory.

In the invention according to claim 2, the method further comprises a calculation step of calculating a data amount of data to be written in the memory, and in the capacity determination step, an arbitrary address in an erase unit area of the memory is included. To the address corresponding to the data amount, it is determined whether or not it is determined in the state determining step that the area is writable, and in the data writing step, the capacity determining step is set to the writable state. Data is written in an area from an arbitrary address determined to be present to an address corresponding to the data amount.

Therefore, when the area from the arbitrary address of the memory to the address corresponding to the data amount of the data to be stored is in the writable state, the arbitrary address is determined as the write start address of the data. As a result, writing can be started without erasing the memory.

According to another aspect of the invention, in the capacity determining step, an area which is determined to be writable in the state determining step in the erase unit area of the memory is written in the memory. If it is determined that the erase unit area is not sufficient for writing the data, the erase unit area is further erased. In the data writing step, the data is written from the start address of the erase unit area that has been erased. Write.

Therefore, in the erase unit area of the memory, only when it is determined that the area determined to be in the writable state is not an area sufficient for writing the data to be written in the memory, the erase unit area is determined. Is erased. Therefore, it is possible to reduce the number of times of erasing processing of the erasing unit area as much as possible, which can contribute to prolonging the life of the memory.

According to another aspect of the present invention, there is provided an address determination processing program for causing a computer to execute a data writing process to a memory, wherein data in an erase unit area of the memory can be sequentially read and written. State determination procedure for determining whether or not the state is writable, and whether or not the area determined to be writable in this state determination procedure is an area sufficient for writing the data to be written in the memory. The computer is caused to execute a capacity determination procedure for determining and a data writing procedure for writing data in an area determined to be an area sufficient for writing data to be written in the memory in the capacity determination procedure.

Further, in the invention according to claim 5, a calculation procedure for calculating a data amount of data to be written in the memory is executed, and in the capacity determination procedure, an arbitrary erase unit area in the memory is selected. It is determined whether or not the area from the address to the address corresponding to the data amount is determined to be writable in the state determination procedure, and in the data writing procedure, the writable state is determined in the capacity determination procedure. Data is written in an area from an arbitrary address determined to be in the area up to an address corresponding to the data amount.

According to another aspect of the invention, in the capacity determining procedure, an area determined to be writable in the erase determining unit area of the memory in the state determining procedure is written in the memory. If it is determined that the area is not enough to write the data to be written, the erasing procedure for erasing the erasing unit area is further executed, and in the data writing procedure, from the top address of the erasing processed area. Write the data.

Therefore, when the computer executes the processing in accordance with the programs described in claims 4 to 6, it is possible to obtain the same effect as that of the invention described in claims 1 to 3.

Further, according to the present invention, in the data writing device for the memory, it is judged whether or not the data in the erase unit area of the memory is sequentially read and is in a writable state. State determining means, a capacity determining means for determining whether or not the area determined to be writable by the state determining means is an area sufficient for writing the data to be written in the memory, and the capacity determining means. Data writing means for writing data to an area determined to be sufficient for writing data to be written in the memory by the determination means.

According to the present invention, there is provided a calculating means for calculating the data amount of the data to be written in the memory, and the capacity judging means is any address in the erase unit area of the memory. To the address corresponding to the data amount, it is determined whether or not the state determining means determines that the state is writable, and the data writing means changes the state to the writable state by the capacity determining means. Data is written in an area from an arbitrary address determined to be present to an address corresponding to the data amount.

Further, in the invention according to claim 9, an area which is judged by the capacity judging means to be writable by the state judging means in the erase unit area of the memory is written in the memory. If it is determined that the erase unit area is not enough to write the data, the erase unit erases the erase unit area. Write.

Therefore, according to the invention described in claims 7 to 9, it is possible to obtain the same effect as that of the invention described in claims 1 to 3 as a data writing device.

[0023]

DETAILED DESCRIPTION OF THE INVENTION

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a block diagram showing a schematic configuration of an apparatus in which a method of writing data in a memory according to an embodiment of the present invention is used. That is, this device has a function of allowing the CPU 1 to control other peripheral devices based on the parameters stored in the flash ROM 3 (flash memory). The flash ROM 3 has a data bus 4
And the CPU 1 via the address bus 5 and CP
Similarly, U1 is connected to the RAM 2 via the data bus 4 and the address bus 5.

FIG. 2 is an explanatory diagram showing the allocation of the flash ROM 3 area in the entire memory area and the configuration in the flash ROM 3. As shown in the figure, the device according to the present embodiment has a memory area of the RAM 2 (RAM area 2
1) and the memory area of the flash ROM 3 (flash R
A memory area including the OM area 31) is used as the entire memory area 10. The flash ROM area 31 is composed of a plurality of areas (sectors (erasure units) 0 to n), and each sector is assigned a data area of several kilobytes.

Further, in the sectors 0 to n, the sector n is the sector in which the parameter which is the data to be written in this embodiment is to be stored. In the sector n, all areas are empty at the initial stage, but as the data writing is performed, the data writing areas “blocks” to which addresses are added are sequentially added to the sectors n.
Formed on top.

In the present embodiment having the above configuration,
The CPU 1 executes the processing shown in the flowchart of FIG. 3 based on the data writing processing program stored in the internal ROM. That is, the CPU 1 uses the flash RO
The parameters to be stored in the sector n of M3 are grouped into one block, and the data size of the parameter block grouped into this one block (hereinafter referred to as parameter size) S
Ize is calculated (step S1). Further, the head address TOP_ADRS of the sector n is set as the initial value of the address variable adrs (step S2).

As described above, the parameter is the sector n.
Address value adrs + SIZE, which is obtained by adding the parameter size SIZE to the address variable adrs.
E is the end address BOTTOM_ADRS of sector n
It is determined whether or not (step S3). As a result of the determination in step S3, adrs + SIZE <BO
If TTOM_ADRS and the address value of adrs + SIZE does not exceed BOTTOM_ADRS,
Even if the parameter writing is started from adrs, the parameter writing end address is BOTTOM_ADRS.
Is not reached. Therefore, in this case, in sector n, from adrs to parameter size SI
A blank check is performed to see if the memory area is empty by ZE.

That is, first, the initial value "0" is assigned to the loop variable i (step S4). Next, adrs +
By reading the 1-byte data at the address i and comparing it with 0xff, it is determined whether or not the area at the address adrs + i is empty (all 8 bits are "1") (step S5). As a result of the determination in step S5, if adrs + i ≠ 0xff and the area at the address adrs + i is not in the empty state, the SIZ is added to the adrs.
The value of E is added to update the value of the address variable adrs indicating the address of the area to be searched next time (step S
6). After that, the processing from step S3 described above is repeated.

As a result of the judgment in step S5,
When rs + i = 0xff and the area at the address adrs + i is empty, it is determined whether the size of the empty area based on the value of the loop variable i is smaller than the parameter size SIZE (step S8). i <SIZ
If E and the size of the empty area based on the value of the loop variable i is smaller than the parameter size SIZE, the value of the loop variable i is incremented (step S7), and then the processing from step S5 is performed again. Run.

Then, the determination result in step S8 is NO.
And the size of the empty area is the parameter size SIZ.
When it is equal to or more than E, it means that the area corresponding to the parameter size SIZE from the address indicated by adrs in the sector n is in an empty state and writable.
Therefore, in this case, the address indicated by the address variable adrs in the sector n is determined as the parameter write start address (step S9).

As a result, writing can be started without erasing the sector n. Therefore, the writing speed of the parameter is improved, and the writing process can be efficiently performed when writing the parameter having a small data amount. Furthermore, sector n
As a result, it is possible to reduce the frequency of erasing processing of the flash ROM 3 and contribute to prolonging the life of the flash ROM 3.

Moreover, in the present embodiment, the value of the loop variable i is incremented in step S7, and the 1-byte data of the incremented address in step S5, that is, the 1-byte data corresponding to the parameter size SIZE is sequentially read. It is determined whether or not the state is “0xff”. Therefore, it is possible to reliably detect whether or not the block having the capacity corresponding to the SIZE is in the writable state. Therefore, a certain area in the block is in a state other than 0xff (unwritable state) due to some influence or cause, and nevertheless, the writing process is performed and the writing failure is surely caused. It can be avoided.

On the other hand, the determination result in step S3 is NO, and the address value adrs + SIZE obtained by adding the data size SIZE to be written to the address variable adrs is added.
If the end address BOTTOM_ADRS of sector n is exceeded, the area of sector n is erased (step S10). Thereafter, TOP_ADRS, which is the start address of sector n, is determined as the parameter write start address (step S11). Therefore, the erasing process is performed on the sector n only when the sector n does not have a free area for the parameter size. Therefore, the number of times of erasing processing of the sector n can be reduced as much as possible, which can contribute to prolonging the life of the flash ROM 3.

In this embodiment, sector n
When searching for an empty area in the area, the address (search area) to be searched is changed for each parameter size SIZE to be written by the processing in step S6, and the search is performed intermittently. The value may be changed one by one from the smaller one, and the search may be performed continuously, and the search may be stopped at the time when an empty area corresponding to the parameter size SIZE to be written is detected (counted). That is, step S3 of FIG. 3 may be set to “adrs + i <BOTTOM_ADRS”, and step S6 may be set to “adrs + i → adrs”. Further, although the case where the data amount of the data to be written to the memory is variable has been described in the present embodiment, the data amount may be fixed instead of being variable, and similar operational effects can be obtained.

[0036]

【The invention's effect】

As described above, according to the present invention, it is determined that the memory is in the writable state, and the determined area is determined to be an area sufficient for writing the data to be written in the memory. Then, since data is written in the area, writing can be started without erasing the memory. Therefore, the write processing speed is improved, and the write processing can be efficiently performed when a parameter having a small data amount is written. Further, it is possible to reduce the frequency of the erasing process of the memory and contribute to prolonging the life of the memory.

In the erase unit area of the memory,
Only when it is determined that the area that is determined to be writable is not sufficient to write the data that should be written to the memory, the erase unit area is erased. While contributing to the long life of the memory by reducing the number of times the area is erased,
Reliable data storage becomes possible.

[Brief description of drawings]

FIG. 1 is a block diagram showing a schematic configuration of an apparatus according to an embodiment of the present invention.

FIG. 2 is an explanatory diagram showing allocation of a flash ROM area in the entire memory area and a configuration in the flash ROM.

FIG. 3 is a flowchart showing a processing procedure of a CPU in the present embodiment.

[Explanation of symbols]

1 CPU 2 RAM 3 Flash ROM 4 data bus 5 address bus

Claims (9)

[Claims] 1. A method of writing data to a memory, comprising: a state determining step of sequentially reading data in an erase unit area of the memory to determine whether or not the state is writable; and a state determining step. A capacity determining step of determining whether or not the area determined to be writable is a sufficient area for writing the data to be written in the memory, and the data to be written in the memory is written in the capacity determining step. And a data writing step of writing data in an area determined to be a sufficient area. 2. A step of calculating a data amount of data to be written in the memory, wherein in the capacity determining step, an area from an arbitrary address in an erase unit area of the memory to an address corresponding to the data amount is included. Is determined to be in a writable state in the state determining step, and in the data writing step, the data is written from an arbitrary address determined to be writable in the capacity determining step. 2. The method for writing data to a memory according to claim 1, wherein the data is written in an area up to an address corresponding to the amount. 3. The area determined to be writable in the state determining step in the erase unit area of the memory in the capacity determining step is not an area sufficient to write data to be written in the memory. The method further comprising an erasing step of erasing the erasing unit area when the determination is made, and in the data writing step, the data is written from a head address of the erasing unit area subjected to the erasing processing. 2. A method for writing data to the memory described in 2. 4. An address determination processing program for causing a computer to execute a data writing process to a memory, a state of determining whether or not data in an erase unit area of the memory is sequentially read and is in a writable state. The determination procedure, the capacity determination procedure for determining whether or not the area determined to be writable in this state determination procedure is an area sufficient for writing the data to be written in the memory, and the capacity determination procedure A data write processing program for causing a computer to execute a data write procedure for writing data in an area determined to be an area sufficient for writing data to be written in the memory. 5. A calculation procedure for calculating a data amount of data to be written in the memory is executed, and in the capacity determination procedure, from an arbitrary address in an erase unit area of the memory to an address corresponding to the data amount. In the data write procedure, it is determined whether or not the area is determined to be in the writable state in the state determination procedure. The data write processing program according to claim 4, wherein the data is written in an area up to an address corresponding to the amount of data. 6. The area determined to be writable by the state determining procedure in the erase unit area of the memory in the capacity determining procedure is not an area sufficient to write data to be written in the memory. 5. When it is determined, an erasing procedure for erasing the erasing unit area is further executed, and in the data writing procedure, data is written from the start address of the erasing processing erased area. Alternatively, the data write processing program according to item 5. 7. A device for writing data to a memory, comprising: a state determination means for sequentially reading data in an erase unit area of the memory to determine whether or not it is in a writable state, and the state determination means. A capacity determining means for determining whether or not the area determined to be writable is a sufficient area for writing the data to be written in the memory, and the capacity determining means for writing the data to be written in the memory. And a data writing unit that writes data in an area determined to be a sufficient area. 8. A calculation means for calculating a data amount of data to be written in the memory, wherein the capacity judgment means is
It is determined whether the area from an arbitrary address in the erase unit area of the memory to an address corresponding to the data amount is determined to be writable by the status determining means. 8. The data writing device according to claim 7, wherein data is written in an area from an arbitrary address determined to be writable by the capacity determination unit to an address corresponding to the data amount. 9. The area determined by the capacity determination means to be writable by the state determination means in the erase unit area of the memory is not an area sufficient for writing data to be written in the memory. 8. The method according to claim 7, further comprising erasing means for erasing the erasing unit area, when the determination is made, wherein the data writing means writes data from a head address of the erasing processing erased area. 8. The data writing device according to item 8.