JP2004192329A - Program rewriting method and terminal device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To rewrite a control program stored in a flash memory in a safe, convenient and economic manner. <P>SOLUTION: An area B for storing the control program, a backup area C and an area A for storing a selection program for selecting the program stored in the area B or the program stored in the area C at the time of booting are provided in the flash memory 20. When booting, the selection program loads the control program to a RAM 30 in the case that the control program is normal, or the selection program loads a program backed up in the area C to the RAM 30 in the case that the control program is not normal. When receiving an instruction to rewrite the control program from a computer 100, the program loaded in the RAM 30 rewrites the control program by clearing the area B after copying a booting program included by the control program stored in the area B to the backup area C. <P>COPYRIGHT: (C)2004,JPO&NCIPI

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a terminal device capable of rewriting a control program and a method for rewriting the control program.
[0002]
[Prior art]
Devices such as printers and network devices are executed by a control program stored in a nonvolatile memory provided therein. This control program is composed of a group of programs (including data; the same applies hereinafter) necessary for executing the apparatus, such as various initialization programs and necessary data. When the apparatus is turned on, the control program stored in the non-volatile memory is copied (loaded) into a volatile memory called RAM provided in the apparatus, and the apparatus is executed.
[0003]
The non-volatile memory is a memory that can retain the stored contents even when the power is turned off, and a ROM is used as a non-volatile memory that stores a control program of the apparatus. The ROM is roughly divided into mask ROM and PROM. The mask ROM is obtained by burning the memory contents on the chip during the LSI manufacturing process, and the memory contents cannot be rewritten. Can be rewritten.
[0004]
Conventionally, a mask ROM has been used as a non-volatile memory for storing a control program of the apparatus because of the advantage of low cost in mass production. However, control programs that are input at the time of shipment from the factory often need to be upgraded after shipment in order to eliminate bugs, increase or decrease functions, and change specifications. In the case of a mask ROM, in order to upgrade the control program, turn off the power of the device equipped with the mask ROM and related devices, remove the ROM from the device, and replace the ROM with a new control program input ROM. Since the control program is upgraded, there are risks such as the cost and annoyance of manufacturing and shipping a new mask ROM on the manufacturer side, and the risk of breaking the ROM due to failure such as the user breaking the connection pin at the time of replacement. For this reason, a PROM that can be rewritten by a user is often used as a non-volatile memory that holds a control program for the apparatus.
[0005]
PROM includes an EPROM that can rewrite the stored contents with a machine called a ROM writer. A user can rewrite a program provided by a manufacturer many times as long as the ROM writer is available. However, there are few users who have a ROM writer other than users such as the development department of the device. For example, purchasing a ROM writer that may be more expensive than a printer for one printer at home is a problem for the user. It is an endurance and a sense of resistance.
[0006]
As a special type of EPROM, there is a non-volatile memory called EEPROM, and this EEPROM is also called flash memory, and can rewrite stored contents electrically. For example, the storage contents of the EEPROM can be rewritten from the computer by electrically connecting to the computer using a communication means such as a network interface such as LAN or WAN, a serial interface (IEEE1394), or a parallel interface (IEEE1284). In this case, in the sense of downloading a program from a computer, a device equipped with an EEPROM can be referred to as a computer terminal device regardless of its type. Under the background of the high penetration rate of computers, users do not purchase a new machine, and new control is provided by the manufacturer using a computer to store a control program stored in the EEPROM of a terminal device such as a printer or network device. It can be rewritten into a program, which is very convenient.
[0007]
In recent years, with the advancement of development technology, large-capacity EEPROMs have become cheaper, so that EEPROMs can be easily used as nonvolatile memories for storing device control programs, and have come to the spotlight.
[0008]
However, when a flash memory, that is, an EEPROM is used as the nonvolatile memory for storing the control program of the apparatus, there is no need for a ROM writer and hardware (ROM) must be replaced in order to upgrade the control program. However, if a write error occurs during rewriting of the control program, an error occurs during the erasing process during rewriting, or the device is turned off during rewriting, the control program is lost. Therefore, there is a risk that not only the control program can be rewritten, but also the normal operation of the apparatus main body cannot be performed.
[0009]
Therefore, Patent Document 1 proposes a rewriting method in which a control program area for storing a control program is divided into a plurality of sections and an error check is performed for each section at the time of rewriting.
[0010]
In Patent Document 2, two flash memories storing control programs are mounted on the apparatus, and a control program stored in one of the two flash memories is selected by a memory selection circuit attached to the CPU of the apparatus. In addition, a method has been proposed in which when a control program is rewritten, the control program stored in one of the non-operating flash memories is rewritten to take measures against an unexpected accident.
[0011]
[Patent Document 1]
JP-A-6-259260 [0012]
[Patent Document 2]
JP-A-7-200306 [0013]
[Problems to be solved by the invention]
However, although the method proposed in Patent Document 1 is effective in preventing errors and shortening the recovery time when rewriting fails, it does not prevent accidental accidents such as power-off during rewriting.
[0014]
Further, the method proposed in Patent Document 2 requires a nonvolatile memory switching circuit and uses a plurality of flash memories each storing a control program having a huge size. There is a problem that becomes expensive.
[0015]
The present invention has been made in view of the above circumstances, and an object thereof is to provide a simple, safe and economical program rewriting method and a terminal device capable of rewriting a control program by this method.
[0016]
[Means for Solving the Problems]
The program rewriting method of the present invention is a program rewriting method for rewriting a control program for executing the terminal device, stored in a flash memory provided in a terminal device, in accordance with a program rewriting instruction from an external processing device. The flash memory is provided with a backup area different from the control program storage area for storing the control program,
A boot program included in the control program, which is necessary for rewriting the control program, is stored in the backup area, and then the control program stored in the control program storage area is rewritten. It is.
[0017]
Here, the “flash memory” means a memory that can retain stored contents even when the power is turned off, and can electrically erase and update the stored contents, and can be an EEPROM.
[0018]
In addition, the “external processing device” means a device that can communicate with the terminal device in the present invention and can perform rewriting by giving a rewriting instruction of the control program stored in the flash memory of the terminal device. Usually, a computer is used.
[0019]
The “terminal device” in the present invention is a terminal device in the sense of acquiring a new control program from a storage medium provided in the external processing device or a location designated by a rewrite instruction from the external processing device. Any device may be used as long as it is a device that can communicate with an external processing device using a flash memory as a memory for storing, for example, a printer, a network device, or the like.
[0020]
Further, the “control program” means a program (including data such as parameters for that) that causes the overall operation of the terminal device according to the present invention. For example, in the case of a printer, it controls printing of the printer. As well as programs for performing the operation of the part, various initialization programs at the time of booting, a print instruction from an external processing device such as a computer, a communication program for receiving print data, and the like are included. In the present invention, the control program includes various programs for rewriting the control program stored in the flash memory of the terminal device.
[0021]
The “boot program” means a program included in the control program and necessary for rewriting the control program. For example, a communication program for receiving a rewrite instruction and new control program data, or control of the flash memory A program for erasing and updating the program storage area can be included. From the viewpoint of saving the flash memory and speeding up the backup of the boot program, the boot program according to the present invention is preferably a program that is necessary and minimum for rewriting the control program.
[0022]
The terminal device of the present invention is a terminal device comprising a flash memory and a program rewriting means capable of rewriting a control program stored in the flash memory in response to a program rewriting instruction from an external processing device,
The control program is for causing the terminal device to execute;
The flash memory determines whether the control program storage area storing the control program, the backup area, and the control program stored in the control program storage area at the time of booting the terminal device are normal, A selection program storage area storing a selection program for selecting whether to execute the control program or to execute the program stored in the backup area based on the result of the determination;
The program rewriting means rewrites the control program stored in the control program storage area after storing the boot program included in the control program necessary for rewriting the control program in the backup area. It is characterized by being.
[0023]
Here, the “program rewriting means” rewrites the control program stored in the control program storage area. For example, a program for rewriting the control program (referred to as a rewrite program) and this program operate. Hardware (such as a CPU). The rewrite program may be stored in the flash memory in the form included in the boot program, or not stored in the boot program but stored in a mask ROM or the like, and controlled using the boot program. The program may be rewritten. That is, the boot program may be composed of a rewrite program for rewriting the control program and a program (such as a communication program for data reception) necessary for the rewrite program to execute. When the rewriting program is independent of the control program, only the program necessary for the rewriting program to execute may be used.
[0024]
【The invention's effect】
According to the program rewriting method and the terminal device of the present invention, when the control program for executing the terminal device stored in the flash memory of the terminal device is rewritten, the boot included in the control program and necessary for rewriting By rewriting after the program is backed up, even if an error or an unexpected accident occurs during rewriting and the rewriting fails, the boot program necessary for rewriting is backed up. It can be rewritten and is safe.
[0025]
Further, since only the boot program is backed up, the required flash memory capacity is small, which is economical.
[0026]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of the present invention will be described with reference to the drawings.
[0027]
FIG. 1 is a block diagram illustrating a configuration of a print system according to an embodiment of the present invention. As shown in the figure, the printing system of this embodiment includes a printer 1 serving as a terminal device and a computer 100 connected to the printer 1 via a network (LAN). The computer 100 is connected to the printer 1. A utility for rewriting the control program of the printer 1 is mounted together with a printer driver for sending printing data and printing.
[0028]
FIG. 2 is a block diagram showing the configuration of the printer 1 in the printing system shown in FIG. As illustrated, the printer 1 according to the present embodiment includes a flash memory 20 that is a non-volatile memory, a volatile memory RAM 30, a print execution unit 50 that prints data transmitted from the computer 100, and communication with the computer. The controller 10 which performs etc. is provided. The flash memory 20 includes an area B that stores a control program including a group of programs (including data) for operating the printer 1, an area C that backs up a boot program included in the control program, and a boot of the printer 1. The control program stored in the area A is sometimes stored in the RAM 30 or the boot program stored in the area C is loaded with the selection program for selecting whether to load the boot program into the RAM 30. Is composed of a rewrite program for erasing or updating the area B, a communication program necessary for the operation of the rewrite program, an initialization program, and the like. When the program stored in the area B or the area C is selected by the selection program, the program is loaded into the RAM 30 to operate the printer 1.
[0029]
Next, the operation of the printer 1 shown in FIG. 2 will be described in detail with reference to FIGS. In order to operate the programs on the flash memory 20 and the RAM 30, a CPU not shown in FIGS. 1 and 2 and various hardware circuits are required. In order to make the gist of the present invention easier to understand, A description of the CPU and various hardware circuits is omitted here.
[0030]
4 is a flowchart showing the overall operation of the printer 1 shown in FIG. 2, and FIG. 3 is a flowchart showing the operation when the control program of the printer 1 shown in FIG. 2 is rewritten. First, an operation when the control program of the printer 1 is rewritten will be described.
[0031]
FIG. 3 shows a rewriting operation from a state in which a boot program (a boot program alone or a control program including a boot program) has already been loaded on the RAM 30 of the printer 1. As shown in the figure, the control program rewriting operation (illustrated operation P) in the printer 1 starts when a rewrite start command is received from the computer 100 via the controller 10. When a rewrite start command is received from the computer 100 (S10), first, the boot program on the RAM 30 copies the boot program included in the control program from the area B of the flash memory 20 to the area C for backup (S12). ). When the backup operation is completed, the boot program (the rewrite program included in the boot program) clears the area B of the flash memory 20 and deletes the existing control program (S14). Next, the boot program writes data composed of new program contents sequentially transmitted from the computer 100 received via the controller 10 to the area B of the flash memory 20 (S16). If an error (writing error, unexpected power off, etc.) occurs during writing (S18: Yes), the writing operation is interrupted. At this time, only the incomplete control program is written in the area B of the flash memory 20, but the boot program is backed up in the area C.
[0032]
If no error occurs (S18: No), the writing to the area B is repeated until a rewrite end command is received from the computer 100 (S20: No). On the other hand, when the rewrite end command is received from the computer 100 (S20: Yes), the boot program on the RAM 30 calculates the SUM value of the new control program written in the area B and returns it to the computer 100 via the controller 10. (S22). The rewriting utility in the computer 100 compares the returned SUM value with the SUM value calculated in advance, and sends a reboot command to the printer 1 if they match. When the boot program receives a reboot command from the computer 100 by the controller 10 (S24: Yes), the printer 1 is reset and restarted (S26), thereby completing the rewriting operation. In this case, a new control program is normally written in the area B.
[0033]
On the other hand, if the SUM value returned from the printer 1 does not match the SUM value calculated in advance on the computer 100 side, the reboot command is not transmitted (S24: No). Then, the rewriting operation is terminated without rebooting the printer 1. In this case, the new control program written in the area B is not normal.
[0034]
When an error occurs during writing or when writing is completed but it is not normal, the user needs to turn the printer 1 on again.
[0035]
FIG. 4 shows the time from when the printer 1 is turned on (normal power-on, reboot at the end of normal rewriting shown in step S26 in FIG. 3, power-on by the user when failed during writing, etc.). It is a flowchart which shows this operation | movement. As shown in the figure, when the printer 1 is turned on, the selection program stored in the area A of the flash memory 20 first calculates the SUM value of the control program in the area B (S50). If the SUM value of the control program is correct (corresponding to the factory-shipped state or the state that has been normally rewritten), the selection program determines that the control program is normal, and selects the control program in region B as the program to be executed. Select (S55: Yes). On the other hand, if the SUM value of the control program is not correct (corresponding to a state where rewriting has failed), the selection program determines that the control program is not normal, and selects the boot program backed up in the area C as a program to be executed. Select (S55: No). The selection program then loads the program of the selected area into the RAM 30 and sets a flag corresponding to the program (S60 to S74). Specifically, if the control program in the area B is selected (S55: Yes), the control program is loaded from the area B into the RAM 30, and the control program flag (81FFFFFFh = 0x00 as an example in this embodiment) is set. (S60, S64) On the other hand, if the boot program in the area C is selected (S55: No), the boot program is loaded from the area C into the RAM 30 and the flag of the boot program (in this embodiment, an example) As 81FFFFFFh = 0x01) is set (S70, S74).
[0036]
Up to this point, the program loading process is performed after the printer 1 is turned on.
[0037]
When the program is loaded into the RAM 30, the startup process of the printer 1 starts. Here, the printer 1 is activated in a different mode depending on the type of program in the RAM 30. That is, if the flag of the program loaded in the RAM 30 is 0 indicating that it is a control program (S80: Yes), the printer 1 is in a normal mode (a mode in which both printing and rewriting are possible) by executing the program. On the other hand, if the flag of the program loaded in the RAM 30 is 1 indicating that it is a boot program (S80: No), the printer 1 is executed in the boot mode (rewrite) by executing the program. (Mode which can only be performed)) (S90).
[0038]
The printer 1 activated in the normal mode waits for an instruction from the computer 100 (S84: No), and receives an instruction from the computer 100 via the controller 10 (S84: Yes). Confirms whether this instruction is a print instruction or a rewrite instruction (S86). If it is a print instruction (S86: Yes), the print execution unit 50 performs printing by a program responsible for printing included in the control program (S88), but if the instruction from the computer 100 is a rewrite instruction (S86) : No), the rewriting operation P shown in FIG. 3 is performed by the boot program included in the control program.
[0039]
On the other hand, the printer 1 activated in the boot mode waits until there is a rewrite instruction from the computer 100 (S95: No), and receives the rewrite instruction from the computer 100 (S95: Yes), the boot loaded in the RAM 30 The program (at this time, only the boot program is loaded on the RAM 30) performs the rewrite operation P shown in FIG.
[0040]
As described above, in the printing system according to the present embodiment, when the printer 1 rewrites the control program stored in the flash memory 20, first, the minimum boot program necessary for the rewriting process included in the control program is stored in the backup area. Since it is copied and backed up to the area C to be backed up, even if it fails in some way during the rewriting process, the boot program remains, so if the printer 1 is turned on again, the control program It is safe because it can be rewritten. Further, since the area C to be backed up is in the same flash memory 20 as the area A storing the control program, and the program to be backed up is a minimum boot program necessary for rewriting, It does not require a complicated switching circuit and is convenient and economical.
[0041]
The printer 1 in the printing system of the present embodiment uses the program rewriting method of the present invention and stores a selection program in the area A of the flash memory 20, and the control program in the area B when the printer 1 is booted by this selection program. If the control program is normal, the printer 1 is started in the normal mode by loading the control program into the RAM 30. If the control program is not normal, the printer 1 is backed up in the area C. Since the boot program is loaded into the RAM 30 and the printer 1 is started in the boot mode so that the control program can be rewritten again, a terminal device that can safely, conveniently and economically rewrite the control program is provided. Realized.
[0042]
In the above description, the preferred embodiment of the present invention has been described. However, the program rewriting method and the terminal device of the present invention are not limited to the above-described embodiment, and various changes, increases / decreases may be made without changing the gist of the present invention. Can be added.
[0043]
For example, the printer 1 shown in FIG. 2 determines whether or not this control program is normal based on the SUM value of the rewritten control program, but whether or not the control program is normal. The determination criterion is not limited to the SUM value, and may be any information as long as it can be determined whether the selection program is normal or not. For example, data indicating whether the program is normal or not provided as ancillary information of the control program may be used. In this case, when the control program is rewritten, the control program is only rewritten when the control program is normally rewritten. Appropriate information indicating normality may be attached to.
[0044]
The printer 1 in the printing system of the embodiment shown in FIG. 1 rewrites the entire control program when rewriting the control program. However, the programs included in the control program are grouped by function into respective areas. When storing and rewriting, it may be possible to selectively rewrite. In this case, the group including the boot program may be a control program defined in the present invention, and the boot program may be backed up only when this group is rewritten.
[0045]
Also, the timing for executing the backup of the boot program is not limited to when the program rewrite instruction is received, but may be any timing before rewriting the control program, that is, before erasing the area storing the control program.
[0046]
Further, the connection and communication mode between the printer 1 and the computer 100 are not limited to the network, and may be performed via a serial interface, a parallel interface, or the like.
[0047]
In the printing system according to the above-described embodiment, data including the contents of the new control program is acquired from the computer 100. However, other computers that store the data and can acquire the data from the terminal device. You may make it acquire from the hard disk of this, the auxiliary storage device with which the terminal device itself was equipped.
[0048]
The program rewriting method and the terminal device of the present invention are not limited to a printer, and can be applied to any device that is executed by a control program stored in a flash memory.
[Brief description of the drawings]
FIG. 1 is a block diagram showing a configuration of a printing system according to an embodiment of the present invention. FIG. 2 is a diagram showing a configuration of a printer 1 in the printing system shown in FIG. 1. FIG. FIG. 4 is a flowchart showing the general operation of the printer 1 shown in FIG.
1 Printer 10 Controller 20 Flash memory 30 RAM
50 print execution unit 100 computer

Claims (2)

In a program rewriting method for rewriting a control program for executing the terminal device stored in a flash memory provided in the terminal device in accordance with a program rewriting instruction from an external processing device,
A backup area different from the control program storage area for storing the control program is provided in the flash memory,
A program included in the control program, wherein a boot program necessary for rewriting the control program is stored in the backup area, and then the control program stored in the control program storage area is rewritten. Rewrite method. A terminal device comprising flash memory and program rewriting means capable of rewriting a control program stored in the flash memory in response to a program rewriting instruction from an external processing device,
The control program is for causing the terminal device to execute;
The flash memory determines whether the control program storage area storing the control program, the backup area, and the control program stored in the control program storage area at the time of booting the terminal device are normal, A selection program storage area storing a selection program for selecting whether to execute the control program or to execute the program stored in the backup area based on the result of the determination;
The program rewriting means rewrites the control program stored in the control program storage area after storing the boot program included in the control program necessary for rewriting the control program in the backup area. A terminal device characterized by being a thing.

Images