JP2004185290A - Reading/writing method to flash memory - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To automatically determine the kind and capacity of a flash memory, to enable writing and reading, and to reduce a load on an operator and work time. <P>SOLUTION: A control program 22 accesses to the flash memory 27 by using one of code sets prepared, and when it does not receive a response from the flash memory 27 in a fixed period of time, it accesses again to the flash memory 27 by using the next code set (Sequence 1 and 2). When a response true "1" is received, the flash memory determines that the code set concerned is the one of usable kind (Sequence 3). The control program 22 accesses to a final address assumed as the capacity of the flash memory and an address exceeding the final address by using the code set thus determined, and the storage capacity of the flash memory is established according to success or failure in the access (Sequence 4 to 7). <P>COPYRIGHT: (C)2004,JPO&NCIPI

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a read / write method for a flash memory, and more particularly, to a read / write method for a flash memory suitable for writing and reading on a flash memory used in a Bluetooth module or the like.
[0002]
[Prior art]
The flash memory used in the Bluetooth module stores firmware for performing overall control of the module, and this firmware may be written or read for an update or the like in some cases. On the other hand, there are a plurality of types of flash memories, control programs that can be controlled differ for each type, and various types have different storage capacities.
[0003]
For this reason, according to the conventional read / write method for a flash memory, when writing and reading to and from a flash memory, a corresponding control program is created for each type of flash memory used, and writing and reading are performed. Previously, it was necessary to determine the control program to be used. Further, in this prior art, when the flash memory is changed to one of a different type and a different capacity, the control program is set again.
[0004]
FIG. 4 is a diagram illustrating an outline of a writing method for a flash memory according to the related art. Now, it is assumed that there are memories A and B as types of flash memories. When information such as firmware is to be written into the memory A, a control program A corresponding to the memory A is prepared. When information such as firmware is to be written into the memory B, Is prepared. When each of the control programs A and B is instructed to write information such as firmware, the information is written to the memories A and B.
[0005]
The types of flash memories and the corresponding control programs do not always correspond one-to-one, and there are cases where several types of flash memories can be controlled by the same control program.
[0006]
Further, as a conventional technique relating to a memory card using this kind of memory, techniques described in Patent Documents 1 and 2 are known.
[0007]
[Patent Document 1]
JP 2000-100196 A
[Patent Document 2]
JP 2000-82122 A
[Problems to be solved by the invention]
As described above, in the method of writing and reading data to and from the flash memory according to the conventional technology, it is necessary to create a control program corresponding to each type of flash memory and determine the control program to be used before writing and reading. Therefore, there is a problem that the work load on the worker is large and the work time is long. In addition, the above-described conventional technique also requires the storage capacity of each flash memory to be checked in advance, which also has a problem that much labor is required.
[0010]
An object of the present invention is to solve the above-described problems of the related art, and to automatically determine the type and storage capacity of a flash memory for performing writing and reading, and to enable writing and reading to and from the flash memory. Accordingly, it is an object of the present invention to provide a read / write method for a flash memory, which can reduce a work load and a working time of an operator.
[0011]
[Means for Solving the Problems]
According to the present invention, an object of the present invention is to provide a read / write method for a flash memory, wherein the control means for controlling read / write to the flash memory uses the fact that the flash memory has different access codes depending on the type thereof. This is achieved by determining the type of the flash memory by trying to access the flash memory using the respective access code, examining the code that successfully accesses the flash memory, and thereafter performing a read or write process. You.
[0012]
Further, the above object is achieved by performing access to an assumed final address or an address exceeding the final address using the determined access code, and determining the storage capacity of the flash memory according to success or failure. .
[0013]
According to the present invention constituted by the above-described means, the type and storage capacity of the flash memory to be written and read can be automatically determined, and the writing and reading to and from the flash memory can be performed. Work load and work time can be reduced.
[0014]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, embodiments of a read / write method for a flash memory according to the present invention will be described in detail with reference to the drawings.
[0015]
FIG. 1 is a diagram for explaining an outline of a method for writing to a flash memory according to an embodiment of the present invention, and FIG. 2 is a block diagram showing a configuration of a device for executing a read / write method for a flash memory according to an embodiment of the present invention. FIG. 3 and FIG. 3 are diagrams showing an operation sequence when writing is performed. 2 and 3, 21 is a PC, 22 is a control program, 23 is a flash memory read / write program, 24 is a Bluetooth module, 25 is a BOOT program, 26 is RAM, 27 is flash memory, and 28 is a serial interface. is there.
[0016]
The present invention makes use of the fact that the access command differs for each type of flash memory and that the storage capacity differs for each flash memory, and automatically discriminates the type of flash memory and its storage capacity. This makes it possible to improve read / write efficiency. That is, the control program used in the present invention determines the type of the flash memory by sequentially trying to access the flash memory according to each assumed access code set of the flash memory and examining the code for which the access is successful. are doing. Further, using the access code set, an access is made to an assumed final address or an address exceeding the final address, and the storage capacity of the flash memory is determined based on the success or failure.
[0017]
As described above, according to an embodiment of the present invention, when writing data or the like to a flash memory, two types of memories A and B are used as described in the related art by one type of control program as shown in FIG. It is also possible to write to the flash memory. Although not shown in FIG. 1, the same applies to reading from a flash memory. Although only two types of memories A and B are shown in the figure, the present invention can be applied to more types of flash memories.
[0018]
As shown in FIG. 2, the configuration of a device that implements the read / write method for a flash memory according to an embodiment of the present invention is, for example, a PC 21 having a control program 22 as a control unit and a read / write program 23 for a flash memory. And a Bluetooth module 24 having a flash memory 27 for storing information such as a BOOT program 25, a RAM 26, and firmware. With this configuration, reading from and writing to the flash memory 27 provided in the Bluetooth module 24 can be performed.
[0019]
In the example shown in FIG. 2, the PC 21 and the Bluetooth module 24 are described as being separated from each other and connected by the serial interface 28. However, the present invention is applied to a case where the Bluetooth module 24 is provided inside the PC 21. Can also be applied.
[0020]
Next, an operation when writing information such as firmware to the flash memory 27 in the example shown in FIG. 2 will be described.
[0021]
(1) When the Bluetooth module 24 is started in a boot mode, which is a mode for writing or reading data to or from a flash memory, instead of a mode for the original operation of the bluetooth module, first, the boot program 25 is stored in the RAM 26. Loaded (expanded).
[0022]
(2) The BOOT program 25 loaded into the RAM 26 fetches the control program 22 from the read / write program 23 of the flash memory of the PC 21 and loads the control program 22 into the RAM 26.
[0023]
(3) After the loading of the control program 22 into the RAM 26 is completed, the control program 22 receives information such as firmware to be written to the flash memory 27 from the read / write program 23 of the flash memory of the PC 21 and flashes the information. Write to the memory 27.
[0024]
Next, a process of acquiring the type and storage capacity of the flash memory when writing to the flash memory 27 as described above will be described with reference to the sequence diagram shown in FIG. In this processing, the control program has a code set corresponding to a plurality of types of flash memories, and a plurality of types of final address values determined by the storage capacity of the flash memory, and uses these to determine the type of the flash memory and its type. This is a process of determining the storage capacity and performing writing.
[0025]
(1) The control program 22 loaded in the RAM 26 accesses the flash memory 27 by using one of the prepared code sets, here, the code set A for writing, for a certain period of time, for example, 100 ms. It waits for a response from the flash memory 27 for about one second after (step (1)).
[0026]
(2) If no response is obtained from the flash memory 27 within a certain period of time, the control program 22 accesses the flash memory 27 again using the next code set, here, the write code set B (sequence). (2)).
[0027]
(3) When a response true “1” is obtained from the flash memory 27 during a certain period of time, the control program 22 determines that the type of the flash memory 27 is a type that can use the code set B for writing. Decide to use that codeset. The processing of the sequences (1) and (2) is repeatedly executed by changing the writing code set until a response true "1" is obtained (sequence (3)).
[0028]
(4) Using the code set determined above, the control program 22 accesses the last address B 'of the flash memory having the smallest memory capacity (sequence (4)).
[0029]
(5) If true “1” is obtained as a response indicating that the access is permitted in the access of sequence (4), the control program 22 determines the last address B ′ + n of the next largest memory capacity in the flash memory. Until a response is obtained, access is made to the last address of a memory having a larger memory capacity (sequences (5) and (6)).
[0030]
(6) In response to the access of the sequence (6), if the file “0” is obtained from the flash memory 27 as a response indicating that access is not possible, the control program 22 determines that the flash memory 27 has Is determined to be the capacity having the last address in (7).
[0031]
(7) Since the type and capacity of the flash memory 27 have been determined by the processing up to this point, the control program 22 then writes necessary data to the flash memory 27 by reading the flash memory 27. -Execute the write program 23 (sequence (8)).
[0032]
In the above-described embodiment of the present invention, the operation has been described by taking data writing to a flash memory as an example, but the present invention can be similarly applied to reading data from a flash memory. That is, in the case of data reading, the type of the flash memory can be determined by using the read code set instead of the write code set described with reference to FIG.
[0033]
In addition, in the above-described embodiment of the present invention, in order to determine the storage capacity of the flash memory, those last addresses are sequentially accessed in order from the smallest memory capacity in the flash memory to the largest one, and access is not possible. Has been described, when the file “0” is obtained as a response, the flash memory 27 is determined to have a capacity having the last address in the previous access from which the response was obtained. It is also possible to access the last addresses in order from the one with the largest memory capacity in the direction from the one having the largest memory capacity, and determine that the capacity has the last address in the access for which the response was obtained.
[0034]
According to the embodiment of the present invention described above, the flash memory takes advantage of the fact that the access code differs depending on the type, tries to access the flash memory using each of the assumed access code sets, By examining the successful code, the type of flash memory can be automatically determined. In addition, although there are flash memories of the same type having different storage capacities, according to the present invention, an access is made to an assumed final address or an address exceeding the final address using a determined access code. The storage capacity of the flash memory can be automatically determined based on the success or failure. Thus, the embodiment of the present invention can improve the work efficiency at the time of writing and reading to the flash memory.
[0035]
【The invention's effect】
As described above, according to the present invention, the type and storage capacity of the flash memory for writing and reading can be automatically determined, and writing and reading to and from the flash memory can be performed. The burden and work time can be reduced.
[Brief description of the drawings]
FIG. 1 is a diagram for explaining an outline of a method for performing writing to a flash memory according to an embodiment of the present invention.
FIG. 2 is a block diagram illustrating a configuration of a device that performs a read / write method for a flash memory according to an embodiment of the present invention.
FIG. 3
FIG. 9 is a diagram illustrating an operation sequence when writing is performed.
FIG. 4
FIG. 3 is a diagram illustrating an outline of a writing method for a flash memory according to a conventional technique.
[Explanation of symbols]
21 PC
22 Control Program 23 Flash Memory Read / Write Program 24 Bluetooth Module 25 BOOT Program 26 RAM
27 Flash memory 28 Serial interface

Claims (2)

In the read / write method for the flash memory, the control means for controlling the read / write to the flash memory uses each of the assumed access codes by utilizing the fact that the flash memory has different access codes depending on the type. A read / write method for a flash memory, characterized in that the type of the flash memory is determined by examining a code that attempts to access the flash memory and succeeds in access, and then executes a read or write process. 2. The flash according to claim 1, wherein an access is made to an assumed final address or an address exceeding the final address using the determined access code, and the storage capacity of the flash memory is determined based on the success or failure. Read / write method for memory.

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