JP2005085121A - Data update method for flash memory, data update program, information processor, and information processing system - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To enable proper calculation of a checksum without being conscious of unnecessary data, a free area size or the like before update by making a flash memory store size information about data on a program to be updated and executing the checksum calculation about only a data area of the updated program on the basis of the size information. <P>SOLUTION: This data update method updating data stored astride a sector of an erasure forbidden area of the flash memory of an information processor includes: an update data writing step for writing update data and the size information about the update data into a prescribed storage area of the flash memory; a size information reading step for reading the size information written into the prescribed storage area of the flash memory; and a checksum calculation step for reading data of only the storage area storing the update data on the basis of the size information, and performing the checksum calculation to the data. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a data update method, a data update program, an information processing apparatus, and an information processing system for updating data stored across sectors in an erasure prohibited area of a flash memory provided in the information processing apparatus.

  The flash memory provided in the information processing apparatus is a memory capable of erasing data in units of sectors, and stores a program for controlling the information processing apparatus, various data, and the like in respective preset storage areas.

  FIG. 8 is a diagram showing a part of a data structure example in a storage area of a conventional flash memory. For example, the data storage area of the program shown in FIG. 8A extends over sectors A and B, and data is stored in a sector having a fixed information storage area, which is an erasure prohibited area of the flash memory, as shown in sector B in the figure. In some cases, the partition of the data storage area does not coincide with the sector boundary.

Conventionally, in a flash memory having such a data structure, when a program is updated and rewritten at the time of version upgrade, old data is erased in units of sectors, and updated new program data is written. However, in the case of FIG. 8A, sector A is completely erased and newly updated new program data is written, but sector B has data in a fixed information storage area which is an erasure prohibited area. (The actual flash memory overwrite operation is performed, for example, by copying the original data to the buffer as it is and overwriting the data on the buffer, erasing the sector B, and changing the contents of the buffer to the sector Write to B).
Therefore, when the stored program data is rewritten by, for example, upgrading, if the data amount is smaller than that of the old program data, the updated new program data is written as shown in FIG. Some of the old program data will remain.

  In the conventional information processing apparatus, since the checksum calculation is performed on the entire program data area, even if rewriting with update data is normally completed, the checksum calculation is not necessary in the example shown in FIG. 8B. There is a problem in that even old program data is added, resulting in a checksum error.

In addition, in the calculation of the checksum of the flash memory, the value also changes depending on the free area size that changes according to the change in the program data size, resulting in a checksum error. In addition, a data writing method and a checksum calculation method in consideration of a free area have been proposed (for example, see Patent Document 1).
JP 2001-175478 A (pages 4-7, FIG. 4)

  However, conventional data update methods and checksum calculation methods that take into account free space are based on the assumption that the boundaries of the program data area coincide with the boundaries between sectors, and that all sectors of the program data area can be erased. The above problems were not completely solved.

  The present invention solves the conventional problem as described above, stores the size information of the program data to be updated in the flash memory, and checks only the data area of the updated program based on the size information. Flash memory data update method, data update program, information processing apparatus, and information processing that can accurately perform checksum calculation without being aware of unnecessary data or free space size before update by performing sum calculation The purpose is to provide a system.

  In order to solve the above-described problem, a data update method according to claim 1 is a data update method for updating data stored across sectors in an erase prohibition area of a flash memory provided in an information processing device. An update data write step for writing update data and size information of the update data in a predetermined storage area of the flash memory, and a size information read step for reading the size information written in the predetermined storage area of the flash memory. And a checksum calculation step of reading data only in the storage area in which the update data is stored based on the size information and performing a checksum calculation on the data.

  The data update method according to claim 2 is characterized in that the size reading step and the checksum calculation step are executed when the information processing apparatus is restarted.

  The data update method according to claim 3 is characterized in that the data stored in the flash memory is data of a program for controlling the information processing apparatus.

  The data update method according to claim 4 is characterized in that the information processing apparatus is a printer.

  The data update method according to claim 5 is characterized in that the data stored in the flash memory is font data of the printer.

  The data update program according to claim 6 is a data update program for causing a computer to realize a function of updating data stored across sectors in an erasure prohibited area of a flash memory provided in an information processing apparatus, An update data write function for writing update data and size information of the update data in a predetermined storage area of the flash memory, and a size information read function for reading the size information written in the predetermined storage area of the flash memory; And a checksum calculation function for reading out only data in the storage area in which the update data is stored based on the size information and performing a checksum calculation on the data.

  The information processing apparatus according to claim 7, wherein the information processing apparatus includes data update means for updating data stored across sectors in an erasure prohibited area of a flash memory provided in the information processing apparatus, The update means includes update data writing means for writing update data and size information of the update data in a predetermined storage area of the flash memory, and a size for reading the size information written in the predetermined storage area of the flash memory. It comprises information reading means and checksum calculation means for reading only data in the storage area in which the update data is stored based on the size information and performing checksum calculation on the data. .

  An information processing apparatus according to an eighth aspect is characterized in that the data stored in the flash memory is data of a program for controlling the information processing apparatus.

  The information processing apparatus according to claim 9 is characterized in that the information processing apparatus is a printer.

  The information processing apparatus according to claim 10 is characterized in that the data stored in the flash memory is font data of the printer.

  An information processing system according to claim 11 is connected to the information processing apparatus according to any one of claims 7 to 10 and the information processing apparatus, and transmits update data including data size information to the information processing apparatus. And a host computer.

  As described above, according to the data update method, data update program, information processing apparatus, and information processing system of the flash memory according to the present invention, it is not affected by unnecessary data before update or the data size of a free area. Since the checksum calculation is executed only for the updated data, it is possible to prevent the occurrence of a checksum error even if rewriting is completed normally when the program data etc. are updated due to version upgrade etc. . In addition, complicated work such as creation of update program data in consideration of the free area size of the sector becomes unnecessary.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. In this embodiment, a printer is used as an example of the information processing apparatus.

First, a schematic configuration of the printer will be described. FIG. 1 is a perspective view showing a schematic configuration of a printer according to an embodiment of the present invention.
As shown in FIG. 1, the printer 10 includes a casing 11 having a front opening and a lid 12 that covers the front opening so that the front opening can be opened and closed. In addition, internal maintenance and inspection are possible.

  The continuous paper is stored in a paper storage unit (not shown) inside the printer in a wound state. Further, the leading end side of the continuous paper fed out from the paper storage unit is guided out of the housing from the paper discharge port 13 via a conveyance path (not shown).

The printer 10 is connected to a host computer 70 (see FIG. 2) via a connector or the like, and performs print control in accordance with a print instruction from the host computer.
That is, according to a printing instruction from the host computer, the printing mechanism unit 50 including the printing head (thermal head) 51, the platen roller 52, and the cutter mechanism 53 arranged on the conveyance path is appropriately driven (see FIG. 2). Then, the continuous paper is transported toward the paper discharge port 13, and characters (characters, symbols, etc.) and pictures are printed along with the transport.
Then, the printing is completed, the continuous paper is further conveyed, and when the rear end position of the printed portion reaches the cutting position of the cutter mechanism, it is cut and separated by the cutter mechanism, and is cut out from the paper discharge port 13 as a cut sheet paper. Provided to the operator.

In addition, a plurality of LEDs 41, 42, and 43 are provided on the front surface of the lid 12 to display the operation status in the printer 10 and various errors.
Note that error notification may be performed more effectively by generating a beep sound or the like simultaneously with the lighting of the LEDs 41, 42, and 43.

Next, a printer according to an embodiment of the present invention will be described with reference to the drawings. FIG. 2 is a functional block diagram illustrating the configuration of the printer.
As shown in FIG. 2, the printer 10 includes a control unit 20, an operation unit 30, a display unit 40, a printing mechanism unit 50, and an input / output interface unit 60. The printer 10 is connected to a host computer 70 serving as a data writing device and constitutes an information processing system.

  The control unit 20 is a block that performs control related to the operation of the printer 10. The CPU 21 controls the overall operation of the printer 10, the flash memory 22 that stores a control program executed by the CPU 21, and the work area of the CPU 21. And a RAM 23.

  The operation unit 30 includes various keys and buttons for inputting operation commands to the printer 10. In addition, the display unit 40 includes LEDs 41, 42, 43 and the like for notifying the operation status and errors of the printer 10.

Further, transmission / reception of data and commands between the printer 10 (control unit 20) and the host computer 70 is executed via the input / output interface unit 60.
In the information processing system according to the embodiment of the present invention, the printer 10 receives print data, update data of various control programs for the printer 10, and the like from the host computer 70.

Here, the internal data structure of the flash memory 22 will be described. FIG. 3 is a memory map showing the data structure of the flash memory of the printer in the embodiment of the present invention.
The flash memory 22 is subdivided into a boot area, a fixed information storage area, a program data area, a graphics data storage area, and a font data area.

  The boot area stores a start program for starting the entire program, a communication program for receiving write data from an external data writing device (that is, the host computer 70), a rewrite execution program, a checksum calculation program, and the like. ing.

  The fixed information storage area stores information such as the model name code, serial number, checksum, and checksum target area size information of the printer 10.

  The program data area stores a program for controlling the printer 10 and the like. This rewriting of the program occurs, for example, due to version upgrade and the rewriting of this area is executed. When rewriting, the free space size at the end of the region changes depending on the size of the update program data.

The graphics data storage area stores image data such as logo marks, and the font data area stores character data.
For example, if it is desired to change the corresponding language, it is necessary to change the font data, so rewriting is also required in this area. Naturally, as described above, the free space size at the end of the region changes depending on the size of the font data to be rewritten.

Next, the program rewriting operation of the printer 10 will be described.
Note that update program data, which is rewrite data, is received from a host computer 70 or the like as a data writing device.

FIG. 4 is a flowchart showing the procedure of the program update operation of the printer according to the embodiment of the present invention.
First, when the operator of the printer 10 makes a predetermined input, the CPU 21 detects this and shifts to the data update mode (S101). The CPU 21 receives the rewrite data from the host computer 70 (S102) and stores it in the RAM 23 (S103).

  A communication program for receiving update program data from the host computer 70 is read from the flash memory 22 in advance.

Here, the rewrite data includes a header including data such as a model name code, a board name code, a date, and a version number of the printer 10 to be rewritten, and information such as an update program, the data size of the update program, and a checksum. It includes write information and a footer indicating the end of data.
The CPU 21 determines a rewrite target from the header information (S104).

  Next, the CPU 21 reads in advance a rewrite execution program necessary for writing from the boot area of the flash memory 22 and stores it in the RAM 23 (S105).

  Next, the CPU 21 writes the update program data temporarily stored in the RAM 23 to the program data area of the flash memory 22 (S106). At this time, the data size and checksum of the update program data are written to a fixed address corresponding to the version of the update program in the fixed information storage area of the flash memory 22.

Next, a checksum calculation operation after data rewriting of the printer 10 will be described.
FIG. 5 is a flowchart showing the procedure of the checksum calculation operation of the printer according to the embodiment of the present invention.

  First, the CPU 21 accesses a fixed address corresponding to the version of the update program in the fixed information storage area in the flash memory 22 according to the checksum calculation program, and writes the size of the checksum target area (that is, the above procedure). (Data size of the update program that has been performed) information is acquired (S201).

Next, the CPU 21 determines whether or not the size of the target area is larger than the program data area of the flash memory 22 (S202).
When the data size is larger than the program data area (S202; YES), it is assumed that the data size of the update program is too large to be stored in the program data area, so the CPU 21 determines that an error has occurred.
On the other hand, when the data size is the same as or smaller than the program data area (S202; NO), the CPU 21 sets the read pointer at the head of the checksum target area (S203). In the example of the memory map of FIG. 3, a read pointer is set at address FA0000.

Next, the CPU 21 clears and initializes both parameters of the variable SUM and the read size (S204). Thereafter, when data reading is started, the CPU 21 substitutes the value of the read data into the variable DATA, and increments the read size parameter by 1 (S205).
Then, the CPU 21 adds the value of the variable DATA to the value of the variable SUM (S206).

Next, the CPU 21 determines whether or not the read size is smaller than the target area size (S207).
That is, in this step S207, it is determined whether or not reading of the stored update program portion in the program data area has been completed. When the read size is smaller than the target area size, that is, when the reading of the update program part is not completed (S207; YES), the read pointer is advanced by 1 (S208), and the process returns to step S205 and the same procedure is performed. Data is read repeatedly.

  On the other hand, when the read size is equal to or larger than the target area size, that is, when the reading of the update program part is completed (S207; NO), the process proceeds to step S209, and the fixed information storage area of the flash memory 22 is stored. Access and get checksum information.

  The CPU 21 adds the acquired checksum to the variable SUM (S210), and determines whether or not the lower 4 digits of the variable SUM are FFFF (hexadecimal number) (S211).

As described above, since the checksum calculated in advance so that the lower 4 digits of the sum of the update program data and the sum of the checksum is FFFF (hexadecimal number) is stored in the fixed information storage area of the flash memory, When the lower 4 digits of the variable SUM do not become FFFF, it is determined that a data write or the like has occurred and normal writing (rewriting) has not been performed, that is, a checksum error.
On the other hand, when the lower 4 digits of the variable SUM are FFFF, it is determined that the checksum is normal.

  The CPU 21 similarly performs the above checksum calculation operation based on the data size information even when the printer 10 is turned off and then turned on again.

When rewriting is performed as described above, the operation status or error can be notified to the operator by using the LEDs 41, 42, and 43 provided in the printer 10.
As the notification method, for example, one LED of the LEDs 41, 42, and 43 is used, and by changing the blinking pattern, a plurality of types of information can be notified to the operator.

  For example, as shown in FIG. 6, during rewriting of a program to the printer 10, what rewriting operation is currently performed can be notified by a blinking pattern of LEDs. In the example shown in FIG. 6, three types of flashing patterns are set, a normal data rewrite mode according to a command from the host computer 70, a forced rewrite mode that shifts to a data update mode by operation of the operation unit 30, and a check It can be grasped by the operator visually observing the blinking of the LED which is the rewriting mode due to the thumb error.

  Further, as shown in FIG. 7, it is possible to change the blinking pattern in accordance with the type of rewriting program that is currently activated (program A, program B, program C). As an example of the rewriting program, there are a program for rewriting program data and font data at the same time, a program for rewriting only program data, a program for rewriting only font data, and the like.

  As described above, according to the notification method using the LED blinking pattern, the LED blinks in a predetermined pattern during the program rewriting, so that the printer 10 is inadvertently turned off during the program rewriting and the rewriting operation is performed. The situation of failure is prevented.

  As described above, conventionally, since the checksum is calculated over the entire sector including the program data area, it seems that the program data before update remains immediately after the updated program area. In this case, a checksum error may occur even if the rewriting is completed normally. However, according to the above data update method, the data size of the update program is stored in a predetermined area in the flash memory. Based on the stored data size information, the checksum can be calculated only in the checksum target area (that is, the update program portion).

  That is, unnecessary data in the program data area is prevented from being used for checksum calculation. In addition, since troublesome work such as preparation of an update program in consideration of the free area in advance and preparation of a special program for calculating the size of the free area of the flash memory to be rewritten is unnecessary, the printer (information processing apparatus) The operator can perform the program rewrite operation accurately without being aware of the free space that changes depending on the data size of the update program.

  In the present embodiment, the case of rewriting the printer program has been described as an example of the checksum calculation operation. Needless to say, for example, the same checksum calculation method can be applied when rewriting font data (that is, data). Yes.

  That is, it is possible to rewrite program data such as a control program or data such as font data. In the above-described embodiment of the invention, the printer is used. However, the specific configuration is not limited to this embodiment, and any information processing apparatus including a flash memory may be used. Applicable.

  As described above, the present invention can be effectively used for an information processing apparatus such as a printer having a flash memory.

1 is a diagram illustrating a schematic configuration of a printer according to an embodiment of the present invention. 1 is a diagram illustrating an internal configuration of a printer according to an embodiment of the present invention. It is a figure which shows the data structure of the flash memory of the printer in embodiment which concerns on this invention. 6 is a flowchart illustrating a procedure of a program rewrite operation of the printer according to the embodiment of the present invention. It is a flowchart which shows the procedure of the checksum calculation operation | movement of the printer in embodiment which concerns on this invention. It is a figure which shows an example of the LED blink pattern of the printer in embodiment which concerns on this invention. It is a figure which shows the other example of the LED blink pattern of the printer in embodiment which concerns on this invention. It is a figure which shows the example of a data structure in the writable area | region of the conventional flash memory.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 10 ... Printer (information processing apparatus), 11 ... Case, 12 ... Cover, 20 ... Control part, 21 ... CPU, 22 ... Flash memory, 23 ... RAM 41, 42, 43 ... LED, 70 ... host computer

Claims (11)

A data update method for updating data stored across sectors in an erasure prohibited area of a flash memory provided in an information processing device,
An update data writing step of writing update data and size information of the update data respectively in a predetermined storage area of the flash memory;
A size information reading step of reading the size information written in a predetermined storage area of the flash memory;
A data update method comprising: a checksum calculation step of reading only data in a storage area in which the update data is stored based on the size information and performing a checksum calculation on the data. The data update method according to claim 1, wherein the size reading step and the checksum calculation step are executed when the information processing apparatus is restarted. The data update method according to claim 1, wherein the data stored in the flash memory is data of a program that controls the information processing apparatus. The data update method according to claim 1, wherein the information processing apparatus is a printer. 5. The data updating method according to claim 4, wherein the data stored in the flash memory is font data of the printer. A data update program for causing a computer to realize a function of updating data stored across sectors in an erasure prohibited area of a flash memory provided in an information processing apparatus,
An update data writing function for writing update data and size information of the update data in a predetermined storage area of the flash memory,
A size information read function for reading the size information written in a predetermined storage area of the flash memory;
A data update program comprising: a checksum calculation function that reads out only data in a storage area in which the update data is stored based on the size information and performs a checksum calculation on the data. An information processing apparatus having data updating means for updating data stored across sectors in an erasure prohibited area of a flash memory provided in the information processing apparatus,
The data update means includes
Update data writing means for writing update data and size information of the update data in a predetermined storage area of the flash memory, and
Size information reading means for reading the size information written in a predetermined storage area of the flash memory;
An information processing apparatus comprising: checksum calculation means for reading out data only in a storage area in which the update data is stored based on the size information and performing checksum calculation on the data. The information processing apparatus according to claim 7, wherein the data stored in the flash memory is data of a program that controls the information processing apparatus. The information processing apparatus according to claim 7, wherein the information processing apparatus is a printer. The information processing apparatus according to claim 9, wherein the data stored in the flash memory is font data of the printer. An information processing apparatus according to claim 7, and a host computer connected to the information processing apparatus and transmitting update data including data size information to the information processing apparatus. Information processing system.

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