JP2009194641A - Facsimile machine - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a facsimile machine by which a restarted CPU can continue the absolute minimum processing, and the behavior of the CPU restarted after runaway is made appropriate even when contents of a program to be processed by the CPU and/or a storage device storing the program are damaged. <P>SOLUTION: The facsimile machine is provided with: the CPU for performing communication control of facsimile; a first storage device for previously storing contents of a main program to be processed by the CPU for communication control; a second storage device for previously storing contents of a sub program to be processed by the CPU for communication control; an activation part for starting the processing of the CPU in accordance with an instruction from a user; and a runaway monitoring part for detecting a runaway state to restart the CPU when the CPU performs the runaway. The runaway monitoring part makes the CPU access a second storage device to process the sub program when the runaway state is detected to restart the CPU and makes the CPU access a first storage device to process the main program when started by the starting part. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a facsimile machine, and more particularly to a facsimile machine having a function of detecting CPU runaway.

  The facsimile machine is usually used in a state where the power is always turned on so that the image can be received whenever the image is transmitted from the other party. It is customary to maintain the reception standby state with the power turned on even at night when there are no people nearby in a general office or the like. It is not allowed that such a nighttime reception causes a failure of the device and the received content is lost.

  As described above, since the facsimile apparatus is used in a state in which the power is always turned on, higher reliability is desired as compared with a device in which the power is turned on before use and the power is turned off after use. In recent years, CPUs or microcomputers are also used for controlling such facsimile machines. Generally, the CPU may go into a runaway (hang-up) state due to disturbance noise or a program bug. Therefore, in devices that require high reliability such as facsimile machines, protection against CPU runaway is added. Many have been done.

  One well-known protection technique is to add an external circuit called a watchdog timer. This is to forcibly restart the CPU by its external circuit when the CPU goes into a runaway state. In other words, while the CPU is operating normally, it is programmed to reset the watchdog timer within a predetermined period, and if the watchdog timer is not reset within the predetermined period as a result of the program runaway, the watchdog timer will eventually overflow. The CPU is forcibly reset.

If the device is composed of multiple controllers (main controller, facsimile controller, printer controller, etc.), a communication confirmation command is sent from the facsimile controller or printer controller to the main controller at regular intervals. Is known to run out of control and issue a restart (reset) signal to the controller to restart it (see, for example, Patent Document 1).
JP 2001-71591 A

  Even when the device has a protection function against runaway as described above, for example, the storage device storing the program to be processed by the CPU is destroyed in hardware, or the data stored in the storage device is destroyed. If this happens, the restarted CPU will not be able to perform regular program processing. For example, when the program is stored in a rewritable storage device such as a flash memory, the data is rewritten or erased.

  In recent years, device control programs are often upgraded. Among such devices, there is a device in which a storage device is mounted on a socket so that the device can be replaced in order to realize an upgrade to a device already sold. Further, in order to reduce the cost and time burden associated with the version upgrade, a function for causing the CPU to process a special program (rewrite program) for updating the program while the storage device is mounted on the board is provided. There are also things.

  However, for example, when the CPU runs out of control, the data stored in the storage device may be destroyed if the above-described rewrite program happens to be executed. Since the state when the CPU runs away cannot be predicted in advance, it cannot be guaranteed that the rewriting program will not be executed.

  From the standpoint of reducing the risk of accidental rewriting of a program, it may be advantageous to mount the storage device in a socket and replace it manually, but the situation is the same if the storage device is broken down in hardware. . Moreover, the burden which a socket and replacement parts require is large.

  The present invention has been made in consideration of the above circumstances, and the CPU after restarting even when the contents of the program to be processed by the CPU and / or the storage device storing the program is destroyed. Therefore, it is possible to provide a facsimile apparatus that can continue the minimum necessary processing, and to make the behavior of the CPU restarted after runaway appropriate.

  The present invention includes a CPU that performs communication control of facsimile, a first storage device that stores in advance the contents of a main program to be processed by the CPU for communication control, and the CPU to process for communication control. A second storage device that pre-stores the contents of the subprogram, an activation unit that starts processing by the CPU in response to an instruction from the user, and if the CPU runs out of control, detects the runaway state and restarts the CPU. The runaway monitoring unit is activated, and when the runaway state is detected and restarted, the runaway monitoring unit is activated by the activation unit so that the CPU can access the second storage device to process the subprogram. When this is done, the facsimile apparatus is characterized in that the main program is processed by allowing the CPU to access the first storage device.

  In the facsimile apparatus according to the present invention, when the runaway state is detected and restarted, the runaway monitoring unit causes the CPU to access the second storage device so that the subprogram is processed, and is started by the starting unit. Since the main program is processed by accessing the first storage device to the CPU, the contents of the program to be processed by the CPU and / or the storage device storing the program are destroyed. It is possible to allow the CPU after the restart to continue the minimum necessary processing, and to make the behavior of the restarted CPU after the runaway appropriate.

  That is, according to the present invention, the main program and the sub program are written in different storage devices in different storage devices in advance, and after the runaway state of the CPU is detected, the sub program is started. Even if the contents are destroyed, it is possible to minimize the downtime of the apparatus. Further, since a different storage device is accessed after the CPU runaway state is detected, the program is executed in a specific area in the first storage device when the first storage device is destroyed in hardware. Even if the CPU loops out of control, the restarted CPU can execute processing without being affected by these problems.

In the present invention, the CPU includes a microcomputer (MPU). In the embodiments described later, the FAX control unit corresponds to the CPU of the present invention.
In the present invention, the activation unit activates the CPU in accordance with an instruction from the user. A specific aspect is, for example, a main power switch provided in the apparatus. In the embodiment described later, the main switch corresponds to the activation unit.
In the present invention, the runaway monitoring unit is a circuit that detects a runaway state of the CPU, resets and restarts the CPU, and defines a storage location of a program to be accessed by the CPU after the restart. A specific mode for detecting CPU runaway is, for example, a watchdog timer. Further, a specific mode of the circuit that defines the access destination of the program accessed after the CPU is activated is, for example, an address control circuit that associates the first and second storage devices with the address space of the CPU.

  The address control circuit arranges the first and second storage devices in a predetermined address space so that a start address when a runaway state is detected and restarted is different from a start address during normal operation. It may be a circuit. For example, the CPU is configured to obtain a restart destination address (so-called reset vector) from a different address in the address space in response to a normal reset signal and a reset signal generated by overflow of the watchdog timer. If so, set the start address of the main program in the vector area corresponding to the normal reset signal, and set the start address of the subprogram in the vector area corresponding to the reset signal related to the watchdog timer. .

  In addition, if the CPU does not have a function to divide the reset vector between the normal reset signal and the reset signal related to the watchdog timer, it depends on which reset signal is used to restart the address space. The physical memory element assigned to the address where the reset vector is arranged may be dynamically changed. That is, when restarting with a normal reset signal, the first storage element is assigned to the reset vector area to indicate the beginning of the main program, and when restarting with a reset signal related to the watchdog timer, The second storage element may be assigned to the reset vector area to indicate the top of the subprogram.

In an address control circuit (so-called address decoding circuit) that assigns a physical storage device to the CPU address space, a method of dynamically changing the physical storage device assigned to the reset vector area when the CPU is reset is known. (See, for example, Masanori Okada, Drudgea Technology Special Edition Memory IC Utilization Handbook, first edition, published by CQ Publishing Co., Ltd., July 10, 1989, p.74-75). This method can be applied to the present invention.
The runaway monitoring unit corresponds to a FAX runaway monitoring unit according to an embodiment described later.

  In the present invention, the first and second storage devices are physically different storage devices. A specific aspect of each storage device is, for example, a nonvolatile semiconductor storage device represented by a flash memory. However, other types of nonvolatile semiconductor memory devices or nonvolatile memory devices other than semiconductors may be used. It does not matter whether it can be rewritten. Further, the types of storage devices may be different between the first and second storage devices.

Hereinafter, preferred embodiments of the present invention will be described. In the embodiments described later, the first storage device corresponds to a first ROM, and the second storage device corresponds to a second ROM.
A document reading unit for reading a document to be transmitted and a printing unit for printing received facsimile data are further provided. The document reading unit has a normal mode in which a document can be read and a power saving mode. Therefore, the printing unit can take a normal mode in which facsimile data can be printed and a standby mode in which the printing operation is stopped for power saving. The main program causes the CPU to make a request that the document reading unit and the printing unit should take the normal mode and a standby mode based on a predetermined condition, and the subprogram includes the document reading unit and the The print unit may cause the CPU to make a request to take the standby mode but not make the request to take the normal mode state. In this way, the subprogram does not operate the document reading unit and / or the printing unit in the normal mode. Therefore, if a runaway occurs due to the control or operation of the document reading unit and / or the printing unit, It is possible to avoid repeated runaway and restart for the same cause. Therefore, the risk of runaway recurrence can be further reduced.

  The main program further includes a power supply unit that supplies power to the document reading unit and the printing unit, and that can supply and shut off power to the document reading unit and the printing unit based on a request from the CPU. Causes the CPU to request the power supply unit to supply power to the document reading unit and to cut off the power supply based on the conditions, and the subprogram is configured to supply power to the document reading unit. The CPU may make a request to be cut off, but may not make a request to supply power. In this way, wasteful power consumption can be suppressed by shutting off the power supply to the document reading unit that does not perform the document reading operation after the restart. In particular, when a runaway state is detected in the night reception standby state and the CPU is restarted, it is possible to avoid a situation in which unnecessary power is consumed by supplying power to the document reading unit after restarting.

  The main program further includes a power supply unit that supplies power to the document reading unit and the printing unit, and that can supply and shut off power to the document reading unit and the printing unit based on a request from the CPU. Causes the CPU to request the power supply unit to supply power to the printing unit and to cut off the power supply based on the conditions, and the subprogram shuts off the power supply to the printing unit. It is possible to cause the CPU to make a power request but not to make a power supply request. In this way, wasteful power consumption can be suppressed by shutting off the supply of power to the printing unit that does not perform the printing operation after the restart. In particular, when a runaway state is detected in the night reception standby state and the CPU is restarted, it is possible to avoid a situation in which unnecessary power is consumed by supplying power to the printing unit after restarting.

  Furthermore, a status output port that outputs a status signal that can identify two or more statuses in accordance with a command from the CPU and maintains the status until the next command is received, and a status for the CPU to read the status of the signal An input port, and the main program causes the CPU to issue a command to output the first status signal to the status output port when the original reading unit and the printing unit make a request to take the normal mode. When making a request to take a mode, the CPU further instructs the CPU to output a second status signal, and the subprogram causes the CPU to read the status of the signal, and based on the read status, It may be determined whether the printing unit should take the normal mode or the standby mode. In this way, even after the runaway state is detected and the CPU is restarted, the subprogram can determine the process according to the mode before the runaway. Therefore, the behavior of the CPU after being restarted can be made appropriate. It is unthinkable that the print status output port is accidentally rewritten in a runaway state, but such an event does not occur with a high probability, and in most cases it is considered to function effectively.

  Further, the display device further includes a display unit for performing display related to facsimile communication, the main program further causes the CPU to make a request to be displayed by the display unit, and the sub-program should have the display unit turn off the display. The request may be made to the CPU but not to be displayed. In this way, since facsimile communication is performed with the display unit turned off, unnecessary power consumption can be avoided. In particular, when a runaway state is detected in the reception standby state at night, this function is effective because it is meaningless to display in a state where there are no people around after the restart. Further, since the display portion is turned off, the user can be made aware of the occurrence of runaway.

  Furthermore, it further includes a voice output unit that outputs a notification related to facsimile communication as voice, and the main program further causes the CPU to make a request for the voice output unit to perform voice output based on a predetermined condition, The subprogram may cause the CPU to further request that the audio output unit stop audio output, but not request to perform audio output. In this way, since facsimile communication is performed in a state where no sound is output, it is possible to avoid unnecessary power consumption. In particular, if a runaway state is detected in the night reception standby state, this function is effective for power saving because it is meaningless to make a voice notification in the absence of a person in the vicinity after restarting.

The CPU may further include a main control unit that controls the document reading unit, the printing unit, and the power supply unit, and the CPU may make a request to the document reading unit, the printing unit, and the power supply unit via the main control unit.
The various preferable aspects shown here can also be combined.

  Hereinafter, the present invention will be described in more detail with reference to the drawings. In addition, the following description is an illustration in all the points, Comprising: It should not be interpreted as limiting this invention.

First, the overall configuration of the facsimile apparatus according to the present invention will be described with reference to an example.

  FIG. 1 is a block diagram showing a schematic configuration of a digital multifunction machine having a facsimile function as an example of a facsimile apparatus of the present invention. As shown in FIG. 1, the digital multi-function peripheral 1 is composed of a plurality of units. That is, the digital multi-function peripheral 1 includes a main control unit (MCU unit) 101 that controls a plurality of attached units, a FAX unit 102 that controls a facsimile communication function, a document reading unit 103 for reading a transmission document, an operation panel 104, It comprises a printing unit 107, a power supply unit 108, and a main switch 131. When the user turns on the main switch 131, power is supplied from the power supply unit 108 to the MCU unit 101, and the control unit 119 starts processing. The MCU unit 101 controls the power supply unit 108 to supply power to each unit. In the configuration of FIG. 1, each unit other than the power supply unit has a CPU. The MCU unit 101 releases the reset signal to each unit and starts the operation of each unit.

  The digital multi-function peripheral 1 controls the printing unit 107, analyzes image data received from the outside, and converts it into data for printing on printing paper. A main control unit (MCU unit) 101 controls the document reading unit 103 to convert an image of the document read by the document reading unit 103 into data for printing on a printing sheet. The FAX unit 102 controls the facsimile function, transmits image data of the document image read by the document reading unit 103 to the other party, and converts the received facsimile data into data to be drawn on the printing paper. The data is printed by the printing unit 107.

  The operation panel 104 includes a display unit 105 on which a partner number or the like is displayed on a liquid crystal, an operation unit 106 such as a numeric keypad, and a voice output unit 130 that informs a message about the operation or status of a fax by voice. The printing unit 107 prints the received image data, and the power supply unit 108 supplies power to each unit, and performs a night FAX mode (standby mode of the present invention) and a normal mode (normal mode of the present invention). , The supply of power to each unit is switched mainly in accordance with a command from the MCU unit 101.

  Next, details of the FAX unit 102 will be described. The NCU 109 included in the FAX unit 102 is a communication unit for hardware connection to a line. The modem 110 is a modem that controls facsimile communication using a telephone line. The image memory 111 is a memory element that stores a FAX image transmitted / received by facsimile communication. The RAM 112 is used as a work memory of the CPU as the FAX control unit 118. The ROM 113 stores the contents of the main program for causing the FAX control unit 118 to function the FAX unit 102. The ROM 114 stores the contents of the subprogram to be processed after restart when the FAX control unit 118 hangs up. The night FAX control unit 115 determines whether the FAX unit 102 should operate in the normal mode or the night FAX mode. Further, the FAX-MCU I / F control unit 116 communicates with the MCU unit 101. A FAX image processing unit 117 compresses and encodes FAX data. Control of the entire FAX unit is performed by the FAX control unit 118.

  Next, the main control unit (MCU unit) 101 will be described. The MCU unit 101 controls each unit. Control is realized by the CPU as the control unit 119 executing a control program. The RAM 120 is used as a work memory for the CPU. The ROM 121 stores the contents of a control program for the CPU to operate the MCU unit and control each unit. The MCU image processing unit 122 compresses and encodes image data exchanged with the FAX unit 102.

Configuration of Runaway Monitoring Unit Next, a detailed configuration of the runaway monitoring unit will be described. FIG. 4 is a block diagram showing a detailed configuration of the runaway monitoring unit 123 according to this embodiment. FIG. 3 is an explanatory diagram showing a CPU address space (determined by output signals CS0 and CS2 to CS6 of an address control unit 126, which will be described later) in a tabular form in this embodiment, a so-called address map.

  The runaway monitoring unit consists of a watchdog timer 124 that detects CPU runaway, a reset signal generation unit 125 that generates a reset signal to the CPU, and an address control unit 126 that determines the storage device to be accessed by the CPU after the reset signal is released The The entities of the watchdog timer 124, the reset signal generation unit 125, and the address control unit 126 are logic circuits corresponding to their functions. For example, these circuits may be mounted on a semiconductor chip as an IC (collected integrated circuit).

  As shown in FIG. 4, A26 to A31 input to the address control unit 126 are CPU address bus signals. The bus control signal is a signal generated based on a signal from the CPU or those signals. The output signals CS0 and CS2 to CS6 are chip select signals and enable selective access to each element described in the “Circuit block name” column of FIG.

  The FAX control unit 118, which is a CPU, is reset by either a reset signal from the MCU unit 101 or a reset signal due to overflow of the watchdog timer 123. In normal operation, it is reset by a reset signal from the MCU unit 101. That is, when the main switch 131 is shut off, the reset signal from the MCU unit 101 is asserted to stop the operation. When the main switch is turned on, the reset signal from the MCU unit 101 is negated and starts.

  At the start, the CPU obtains a reference address (reset vector) of a program to be processed after the start. The address for acquiring the reset vector is predetermined. In this embodiment, the acquisition source of the reset vector when the reset signal from the MCU unit 101 is canceled is the address HFFFF_FF00 in hexadecimal notation (see FIG. 3). The address control unit 126 assigns the first ROM to the address HFFFF_FF00 in the CPU address space only when the CPU acquires the reset vector. Therefore, the chip select signal CS0 is asserted when the reset vector is acquired.

  The CPU acquires a reset vector from a predetermined area of the first ROM. The acquired value is the head address of the main program, that is, H0000_0000 in hexadecimal representation. After acquiring the reset vector, the chip select signal CS0 is asserted only when accessing addresses H0000_0000 to H03FF_FFFF. In this way, the CPU starts processing from the top of the main program.

  The watchdog timer 124 is configured to start the timer counting by the internal clock at the same time when the FAX control unit 118 is activated. Then, the timer count continues while the FAX control unit 118 operates. When the predetermined period elapses, the timer overflows and an overflow signal is output. The timer is reset by a command from the FAX control unit 118.

  The main program and the sub program are programmed so that the FAX control unit 118 issues a reset command to the watch dog timer 123 until the above-described predetermined period has elapsed. The reset command is repeatedly issued at intervals shorter than a predetermined period. Therefore, as long as the FAX control unit 118 executes the main program or subprogram, the watchdog timer 123 does not overflow.

  However, if the FAX control unit 118 cannot correctly execute the main program or subprogram for some reason, a reset command to the watchdog timer 123 cannot be issued. This is a runaway condition. When a runaway state occurs, the watchdog timer 123 eventually overflows and outputs an overflow signal. This signal is input to the reset signal generator 125. The reset signal generation unit 125 generates a reset signal in response to the overflow signal, and resets the FAX control unit 118 regardless of the MCU unit 101. The reset signal is simultaneously input to the address control unit 126.

  In response to the reset signal, the address control unit 126 assigns the second ROM to an address (address HFFFF_FF00) predetermined as the left-hand side of reset vector acquisition at the time of restart by the reset signal. Therefore, the chip select signal CS6 is asserted when the reset vector is acquired. The CPU acquires a reset vector from a predetermined area of the second ROM. The acquired value is the first address of the subprogram, that is, H1800_0000 in hexadecimal notation. After obtaining the reset vector, the chip select signal CS6 is asserted only when accessing addresses H1800_0000 to H1BFF_FFFF. In this way, the CPU starts processing from the top of the subprogram.

Next, an operation when the digital multi-function peripheral 1 is operating normally will be described.
When the main switch of the digital multi-function peripheral 1 is turned on, power is supplied from the power supply unit 108 to the MCU unit 101. Further, the reset signal from the power supply unit 108 to the MCU unit 101 is canceled, and the control unit 119 starts executing the processing. By the processing of the control unit 119, the MCU unit 101 sets the power supply unit 108 to supply power to each unit of the FAX unit 102, the document reading unit 103, the operation panel 104, and the printing unit 107 at the stage of initialization processing. Control. In addition, the reset signal to each unit is canceled. As a result, the CPU of the operation of each unit starts processing. After the main switch is turned on, the digital multifunction peripheral 1 operates in the normal mode.

  Thereafter, when the user gives an instruction to shift to the night FAX mode using the operation unit 106, or when the clock timer function of the night FAX control unit 115 reaches the first predetermined time, a shift request is issued. The digital multifunction device 1 shifts to the night FAX mode. More specifically, when an instruction to shift to the night FAX mode is input using the operation unit 106, the instruction is sent from the operation panel 104 to the MCU unit 101. When a request for shifting to the night FAX mode is issued from the night FAX control unit 115, the request is sent from the FAX unit 102 to the MCU unit 101.

  In response to those instructions or requests, the control unit 119 of the MCU unit 101 issues a command to shift each unit to the standby mode. Each unit shifts to the standby mode in response to a command from the MCU unit 101. That is, in the FAX unit 102, the FAX control unit 118 shifts the FAX unit 102 to the night FAX mode in response to the command. The document reading unit 103 shifts to the normal mode. The operation panel 104 removes some displays or turns off all displays, and stops sound output. The printing unit 107 shifts to the standby mode.

  Alternatively, the MCU unit 101 controls the power supply unit 108 to cut off unnecessary power supply to portions that do not operate during the night FAX mode in each unit. That is, after the reset signal to the document reading unit 103, the operation panel 104, and the printing unit 107 is asserted to stop the operation, the power supply to these units is cut off. This is the ultimate standby mode. In this case, in the digital multi-function peripheral 1, only the FAX unit 102 that performs facsimile transmission / reception operates, and power supply to other units is cut off except for power supply to some necessary parts.

  When facsimile data is received during the night FAX mode, a print request is issued from the night FAX control unit 115 to the MCU unit 101. Upon receiving the request, the control unit 119 of the MCU unit 101 issues a command to return the printing unit 107 to the normal mode in order to perform a printing operation.

  Alternatively, when the supply of power to the printing unit is interrupted, the MCU unit 101 controls the power supply unit 108 to start supplying power to a part necessary for the printing operation. Further, the reset signal to the printing unit 107 is negated. The CPU of the printing unit 107 starts processing, and as a result, the printing unit 107 shifts to the normal mode. Then, the printing unit 107 prints the received facsimile data. When printing is completed, the printing unit 107 notifies the MCU unit 101 of the completion of printing. The MCU unit 101 shifts the printing unit 107 to the standby mode again in response to the print end notification. Alternatively, after the reset signal to the printing unit 107 is asserted, the power to the printing unit 107 is shut off and a transition is made to the ultimate standby mode. In this way, the night fax mode continues.

  Thereafter, the user gives an instruction to shift from the FAX night mode to the normal mode using a predetermined key of the operation unit 106 or a dedicated switch, or the clock timer function of the night FAX control unit 115 is the second. When the predetermined time is reached, the digital multifunction peripheral 1 shifts from the night FAX mode to the normal mode. More specifically, when an instruction to shift to the normal mode is input using the operation unit 106 or a dedicated switch, the instruction is sent to the MCU unit 101. When the night FAX control unit 115 issues a request to shift to the normal mode, the request is sent from the FAX unit 102 to the MCU unit 101.

  The control unit 119 of the MCU unit 101 issues a command so that each unit shifts to normal operation. Alternatively, when power supply to each unit is interrupted, the power supply unit 108 is controlled to start power supply to each unit. Further, the reset signal to each unit is negated to cause the CPU of each unit to start processing. Each unit shifts to the normal mode in response to a command from the MCU unit 101 or a reset release. In the FAX unit 102, the FAX control unit 118 starts normal mode processing of the FAX unit 102. Further, the document reading unit 103 shifts to the normal mode. The operation panel 104 performs display during normal operation and outputs sound according to the setting. The printing unit 107 shifts to the normal mode.

Process Flow when CPU Runaway State is Detected Next, the flow of operation when the FAX runaway monitoring unit 123 detects the runaway state of the FAX control unit 118 in the digital multifunction peripheral 1 will be described with reference to FIG. .

  FIG. 2 is an explanatory diagram showing, in the form of a flowchart, the processing flow of each circuit block when the runaway state of the FAX control unit 118 is detected in this embodiment. It should be noted that the execution subject of the flowchart of FIG. 2 is mainly each circuit block of the FAX runaway monitoring unit 123, and is not a CPU (FAX control unit 118) except for some processes. That is, FIG. 2 is shown in the form of a flowchart for easy understanding of the flow of processing. The steps are not shown.

  When the main switch is turned on and the operation is started normally, the address control unit 126 of the FAX runaway monitoring unit 123 sets the reset vector to the FAX control unit 118 so that the processing of the main program stored in the first ROM is started. Get it (STEP S201).

  The main program causes the FAX control unit 118 (CPU) to execute a command to reset the watch dog timer (hereinafter, WATCHDOC timer) within a predetermined period (STEP S202). As a result, if the CPU goes out of control, the WATCHDOC timer overflows and a CPU hang-up condition is detected.

  As long as the WATCHDOC timer has not overflowed (NO in STEP S203), it is assumed that the CPU is operating normally and has not hung up. The CPU is not restarted by the FAX runaway monitoring unit 123, and as a result, the sub program is not processed.

  In addition, the main program outputs a signal (status signal) indicating whether the digital multifunction peripheral 1 is operating in the normal mode or the FAX night mode to a predetermined output port (the output port is shown in FIGS. 1 and 4). Not shown). This output port corresponds to the status output port of the present invention. The FAX control unit 118 can know this status signal by reading a predetermined input port. This input port corresponds to the state input port of the present invention.

  When the WATCHDOC timer overflows (YES in STEP S203), the address control circuit 126 dynamically arranges the second ROM in the reset vector area so that the FAX control unit 118 acquires a reset vector indicating the head of the subprogram ( STEP S204). When the reset signal is released and restarted (STEP S205), the FAX control unit 118 executes the subprogram stored in the second ROM (STEP S206).

The FAX control unit 118 that executes the subprogram reads the status signal from the status input port (STEP S207), and determines whether the state before the restart is the FAX night mode or the normal mode (STEP S208). A function to be processed is selected according to the determination result.
The following five functions are prepared as subprogram functions.

First function: A function for taking an execution history (log) of a program is prepared.
This function makes it easy to analyze the cause of a problem that occurs again after a restart.

Second function: A function for suppressing the printing operation in the night FAX mode is prepared. Specifically, when facsimile data is received in the night FAX mode, the received data is held in the image memory 111 so that the printing unit 107 does not print it. The target for supplying power during the night FAX mode is limited to the FAX unit 102 and the MCU unit 101.
With this function, power consumption during night FAX mode can be further suppressed, and when runaway occurs due to control or operation of the printing unit, repeated runaway due to the same cause after restart can be avoided. . When the runaway is repeated for the same cause, there is a possibility that the power supply for performing the printing operation may be repeated, and wasteful power consumption can be suppressed from this viewpoint.

Third function: A function is provided to silence the sound output or to turn off the LED and backlight of the display unit.
With this function, wasteful power consumption can be suppressed.

Fourth function: A function for rewriting and rewriting the main program is prepared.
With this function, it is possible to upgrade the main program (firmware upgrade) or to rewrite the regular contents. If the cause of the runaway is due to a bug in the main program, there is a possibility that the cause will be eliminated by version upgrade. In addition, when the contents of the main program are destroyed, there is a possibility that the correct contents can be rewritten and restored.

Fifth function: A function for changing the communication speed and the communication protocol (communication method) from the normal mode is prepared.
With this function, even if the communication speed is somewhat sacrificed, it is possible to prevent reoccurrence when runaway is caused by communication by performing communication in a more stable state. Specifically, communication is performed at a communication speed lower than that in the normal mode, and data corruption check is performed more strictly.

  The description of the flowchart will be continued. When the read status signal indicates the night FAX mode (YES in STEP S208), the FAX control unit 118 executes the first to fifth functions described above (STEP 209). On the other hand, when the status signal is the normal mode (NO in STEP S208), the FAX control unit 118 executes the first, fourth, and fifth functions described above (STEP S211). That is how the subprogram is created.

Here, however, when restarting in the normal mode, the execution of the fourth function (firm up) is reserved and executed after entering the night FAX mode. This is because the main program is rewritten at night when the device is not frequently used (STEP S210).
The above is the flow of operation when a runaway state is detected.

  Here, the explanation about the fifth function will be supplemented. In facsimile communication, the signal transmission level of the transmission source terminal may be abnormally low, or large noise may be superimposed depending on the situation of the telephone line through which the signal is transmitted. For this reason, there is a case where the received signal waveform is so distorted that the transmission source signal cannot be recognized on the receiving side and erroneously detected. In some cases, it can lead to a hang-up. In this way, in the case of hang-up due to external factors (the state of the other party's terminal or the status of the telephone line through), the same operation (hang-up and restart) unless this external factor is removed Is repeated.

  Usually, a communication retry is performed or a line is disconnected due to a communication timeout so that the communication does not fall into an infinite loop or hang up. However, in a poor communication environment, even if communication retries are repeated, a regular signal may not be received and facsimile communication may not be completed. In order to cope with such a situation, it is possible to change the reception sensitivity on the receiving terminal side or change the signal detection time so that the signal can be easily received. Since it is assumed that the person is not in the vicinity, it is not possible to expect a measure to change the setting through human intervention. The above function assumes that regular signals cannot be received during night fax mode, and changes the communication settings of the sub program compared to that of the main program (changes such as increasing the reception sensitivity and extending the detection time) Therefore, it is meaningful to enable more stable reception.

  In addition to the embodiments described above, there can be various modifications of the present invention. These modifications should not be construed as not belonging to the scope of the present invention. The present invention should include the meaning equivalent to the scope of the claims and all modifications within the scope.

1 is a block diagram illustrating a schematic configuration of a digital multi-function peripheral having a facsimile function as an example of a facsimile apparatus of the present invention. In this embodiment, the processing flow of each circuit block when the runaway state of the FAX control unit 118 is detected is an explanatory diagram showing in the form of a flowchart. In this embodiment, it is explanatory drawing which shows the address space of CPU. It is a block diagram which shows the detailed structure of the runaway monitoring part which concerns on this embodiment.

Explanation of symbols

1: Digital MFP
101: Main control unit, MCU unit
102: FAX unit
103: Document reader
104: Operation panel
105: Display section
106: Operation unit
107: Print section
108: Power supply
109: NCU, communication unit
110: Modem
111: Image memory
112: RAM
113: ROM, first storage device
114: ROM, second storage device
115: Night Fax Control
116: FAX-MCU I / F controller
117: FAX image processor
118: FAX control section
119: Control section
120: RAM
121: ROM
122: MCU image processor
123: Fax Runaway Monitoring Department
124: Watchdog timer, WATCH DOC timer
125: Reset signal generator
126: Address control unit
130: Audio output section
131: Main switch

Claims (8)

A CPU for controlling facsimile communication;
A first storage device that stores in advance the contents of a main program to be processed by the CPU for communication control;
A second storage device that stores in advance the contents of a subprogram to be processed by the CPU for communication control;
An activation unit for starting processing by the CPU according to an instruction from the user;
When the CPU runs away, the runaway monitoring unit that detects the runaway state and restarts the CPU,
The runaway monitoring unit causes the CPU to access the second storage device when the runaway state is detected and is restarted, so that the subprogram is processed. A facsimile machine characterized in that a main program is processed by accessing a storage device. An original reading unit for reading an original to be transmitted;
A printing unit for printing the received facsimile data;
The document reading unit can take a normal mode in which a document reading operation is possible and a standby mode in which the reading operation is stopped for power saving.
The printing unit can take a normal mode in which facsimile data can be printed and a standby mode in which the printing operation is stopped for power saving.
The main program causes the CPU to make a request that the original reading unit and the printing unit should take the normal mode and a standby mode based on a predetermined condition,
2. The facsimile apparatus according to claim 1, wherein the sub-program causes the CPU to make a request that the document reading unit and the printing unit should take the standby mode, but does not make a request to take the normal mode state. A power supply unit that supplies power to the document reading unit and the printing unit, respectively, and that can supply and shut off power to the document reading unit and the printing unit based on a request from the CPU;
The main program causes the CPU to supply a request for the power supply unit to supply power to the document reading unit and a request to shut off the power supply based on the conditions,
3. The facsimile apparatus according to claim 2, wherein the subprogram causes the CPU to request that the power supply unit shut off power to the document reading unit, but not to supply power. A power supply unit that supplies power to the document reading unit and the printing unit, respectively, and that can supply and shut off power to the document reading unit and the printing unit based on a request from the CPU;
The main program causes the CPU to supply a request for the power supply unit to supply power to the printing unit and a request to shut off the power supply based on the conditions,
4. The facsimile apparatus according to claim 2, wherein the sub-program causes the CPU to request that the power supply unit shut off power to the printing unit, but not to supply power. A status output port that outputs a status signal that can identify two or more statuses according to the command of the CPU and maintains that status until the next command is received,
A state input port for the CPU to read the state of the signal,
The main program causes the CPU to issue a command to output the first status signal to the status output port when the original reading unit and the printing unit request to take the normal mode, and make a request to enter the standby mode. Sometimes let the CPU give a command to output the second status signal,
5. The subprogram according to claim 3, wherein the subprogram causes the CPU to read the state of the signal and determines whether the document reading unit and the printing unit should take the normal mode or the standby mode based on the read state. The described facsimile machine. A display unit for performing a display related to facsimile communication;
The main program causes the CPU to further request the display unit to display,
6. The facsimile apparatus according to claim 1, wherein the sub program causes the CPU to make a request to turn off the display but does not make a request to display. A voice output unit for outputting a notification related to facsimile communication as voice;
The main program causes the CPU to further request that the audio output unit perform audio output based on a predetermined condition,
The facsimile apparatus according to claim 1, wherein the sub-program causes the CPU to further request that the voice output unit stop the voice output but does not make a request to perform voice output. A main control unit for controlling the document reading unit, the printing unit, and the power supply unit;
The facsimile apparatus according to claim 3 or 4, wherein the CPU makes a request to the document reading unit, the printing unit, and the power supply unit via the main control unit.

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