JP2009301358A - Control board, image forming apparatus having the same, and power saving method for the control board - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a control board for suitably suppressing power consumption in power-saving operation. <P>SOLUTION: The control board has a general operation mode and a power-saving operation mode, and comprises a control part which reads a program from a nonvolatile memory and performs predetermined processing; and a first volatile memory having a work area to be used when the control part performs the predetermined processing. A refresh prohibition part of the control board prohibits refresh of all areas, except at least the work area, of the first volatile memory in the power-saving operation mode (step S25). <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to power saving during standby of a control board, particularly a control board provided in an image forming apparatus.

For example, Patent Document 1 discloses a technique related to power saving during standby of a control system (control board) including a microprocessor or the like. Here, for example, a technique for saving power by performing a self-refresh operation of a volatile memory (SDRAM) that is a main memory of the system at the time of standby of the system is shown.
JP 2004-326153 A

  However, further improvements are desired for power saving during standby of the control board, for example, it is not always necessary to self-refresh the volatile memory during standby of the control board.

  The present invention has been completed based on the above-described circumstances, and an object thereof is to provide a control board capable of suitably suppressing power consumption during a power saving operation.

As means for achieving the above object, a control board according to a first invention is a control board that has a normal operation mode and a power saving operation mode and performs predetermined processing, and is a non-volatile storage for storing a program. A volatile memory, a controller that reads the program from the nonvolatile memory and executes the predetermined process, and a first volatile memory having a work area used when the controller executes the predetermined process; In the power saving operation mode, a refresh prohibiting unit that prohibits refresh except for at least the work area among all the areas of the first volatile memory.
According to this configuration, since it is not necessary to refresh the entire area of the first volatile memory, it is possible to suitably suppress the power consumption of the control board during the power saving operation. Here, the “normal operation mode” of the control board means an operation state in which no power saving measures are performed on each component of the control board. In addition, the “power-saving operation mode” of the control board is an operation state other than the “normal operation mode”, that is, an operation state in which any power-saving measure is applied to any component of the control board. Means. Therefore, the so-called “ready state”, “standby state”, “sleep state”, and the like belong to the “power saving operation mode”.

  According to a second invention, in the control board of the first invention, a cache memory and / or a second volatile memory having a smaller storage capacity than the first volatile memory, and the cache memory and / or the second volatile memory. A save unit that saves the data in the work area of the first volatile memory to the cache memory and / or the second volatile memory when the program operates only with predetermined data stored in the memory And a writing unit that writes the saved data to a work area of the first volatile memory when returning from the power saving operation mode to the normal operation mode, and the refresh prohibiting unit includes: In response to saving of data in the work area, in the power saving operation mode, the entire area of the first volatile memory is refreshed. To prohibit the Interview.

  According to this configuration, since the refresh of the entire area of the first volatile memory is prohibited in the power saving operation mode, the power consumption can be further suppressed. In addition, after the return from the power saving operation mode to the normal operation mode, it is possible to quickly execute a predetermined process.

An image forming apparatus according to a third aspect includes the control board according to the first aspect or the second aspect, and an image forming part that forms an image in accordance with an instruction of the control part of the control board.
According to this configuration, the power consumption of the image forming apparatus can be reduced by suppressing the power consumption of the control board.

4th invention uses the non-volatile memory which stores a program, the control part which reads the said program from the said non-volatile memory, and performs a predetermined process, and when the said control part performs the said predetermined process A first volatile memory having a work area, having a normal operation mode and a power saving operation mode, and a power saving method for a control board for performing a predetermined process, wherein the power saving operation mode includes: A prohibiting step of prohibiting refreshing except for at least the work area out of the entire area of the first volatile memory;
According to this configuration, since it is not necessary to refresh the entire area of the first volatile memory, the power consumption of the control board can be suppressed.

  According to a fifth aspect of the present invention, in the control board power saving method of the fourth aspect, the control board further includes a cache memory and / or a second volatile memory having a smaller storage capacity than the first volatile memory, The nonvolatile memory for returning to the cache memory and / or the second volatile memory in advance from the power saving operation mode to the normal operation mode when shifting from the normal operation mode to the power saving operation mode. In the reservation step of reserving the variable area for the interrupt routine stored in the memory and storing the position of the variable area, and in the power saving operation mode, the control unit performs the cache memory and / or the second volatile property. When the program operates according to the program using a variable stored in a memory, the first volatile memory Variable data in the work area is saved in the cache memory and / or the second non-volatile memory, and a save step for storing the save position, and refreshing the first volatile memory following the save step A refresh step for refreshing the first volatile memory using the interrupt routine and the variable area for the interrupt routine when returning from the power saving operation mode to the normal operation mode. A resetting step for resetting the operation, and when returning to the normal operation mode, data in the work area of the first volatile memory saved in the cache memory and / or the second volatile memory, And a returning step of returning to the work area.

  According to this configuration, since the refresh of the entire area of the first volatile memory is prohibited in the power saving operation mode, the power consumption can be further suppressed. In addition, after the return from the power saving operation mode to the normal operation mode, it is possible to quickly execute a predetermined process.

6th invention uses the non-volatile memory which stores a program, the control part which reads the said program from the said non-volatile memory, and performs a predetermined process, and when the said control part performs the said predetermined process A volatile memory having a work area, and a power saving method for a control board that performs predetermined processing in a normal operation mode and a power saving operation mode. A prohibition step for prohibiting a refresh operation except for at least the work area among all areas of the volatile memory, and an interrupt stored in the volatile memory when returning from the power saving operation to the normal operation mode A routine and a stack area belonging to the work area in the volatile memory are used to refresh the volatile memory. Includes a resetting step for resetting the Interview operation, the.
According to this configuration, since it is not necessary to refresh the entire area of the volatile memory, the power consumption of the control board can be suppressed.

  An image forming apparatus according to a seventh aspect includes a communication unit that communicates data, and performs a printing process based on a control board that operates in a normal operation mode and a power saving operation mode, and print data received by the communication unit. The communication unit is controlled in a standby state in which the printing unit and the predetermined function included in the communication unit are disabled in the power-saving operation mode, and enabling data for enabling the disabled predetermined function can be received. A communication control unit.

  According to this configuration, since the predetermined function included in the communication unit is invalidated, the power consumption of the control board can be suppressed, and the power consumption of the image forming apparatus can be reduced. In addition, the standby state can be canceled by receiving the validation data, and thereafter, the power saving operation mode can be shifted to the normal operation mode.

  According to an eighth aspect of the present invention, in the image forming apparatus according to the seventh aspect of the present invention, the detection unit further detects whether or not a connection unit for communicating the print data with the outside is connected to the communication unit so as to be capable of electrical communication. The communication control unit controls the communication unit to the standby state regardless of whether or not the power saving operation mode is detected when connection of the connection unit is not detected. When the connection of the connection means is detected, the predetermined function is validated and the standby state is released.

  According to this configuration, when the connection capable of electrical communication of the connection unit is not detected, the print data cannot be communicated. Therefore, the standby state may be always set, and the power consumption can be efficiently suppressed. Even in a situation where validation data cannot be received, the standby state can be easily released.

A ninth invention includes an image forming apparatus that includes a communication unit that communicates data, includes a control board that operates in a normal operation mode and a power saving operation mode, and performs image formation processing based on print data received by the communication unit In the power-saving method of the control board, in the power-saving operation mode, the predetermined function included in the communication unit is invalidated, and the validation data for validating the invalidated predetermined function can be received. A control step of controlling the communication unit in a standby state.
According to this configuration, since the predetermined function included in the communication unit is invalidated, the power consumption of the control board can be suppressed, and the power consumption of the image forming apparatus can be reduced.

According to a tenth aspect of the present invention, in the control board power saving method of the ninth aspect of the invention, an adding step of adding the validation data to the print data, and the print data with the validation data added to the communication unit A transmission step of transmitting, and a releasing step of enabling the predetermined function and releasing the standby state in response to reception of the print data to which the validation data is added in the communication unit.
According to this configuration, the standby state can be preferably canceled and the power saving operation mode can be shifted to the normal operation mode by receiving the print data to which the validation data is added.

  In an eleventh aspect of the invention, in the control board power saving method of the ninth aspect of the invention, it is detected whether or not connection means for communicating the print data with the outside is connected to the communication section so as to be capable of electrical communication. A detecting step, and a standby step of setting the communication unit in the standby state regardless of whether the connection unit is not detected in the power saving operation mode; and in the communication unit, the connection unit A release step of enabling the predetermined function and canceling the standby state.

  According to this configuration, when the connection capable of electrical communication of the connection unit is not detected, the print data cannot be communicated. Therefore, the standby state may be always set, and the power consumption can be efficiently suppressed. Even in a situation where validation data cannot be received, the standby state can be canceled by simple means.

  According to the control board of the present invention, the power consumption during the power saving operation can be suitably suppressed.

  An embodiment of the present invention will be described with reference to FIGS.

1. FIG. 1 is a block diagram illustrating a schematic electrical configuration of a printer 1 (an example of an image forming apparatus). The printer 1 is connected to a plurality of computers such as a personal computer (hereinafter simply referred to as “PC”) 40 via a LAN cable 38 and a communication line 37. The printer 1 may be a laser printer or an ink jet printer. Further, it may be a facsimile machine or a multi-function machine having a printer function and a reading function (scanner function).

  The printer 1 includes a control board 5, an image forming unit 10, an operation unit 34, and a display unit 35. The control board 5 includes a network interface (an example of a communication unit) 20, a CPU (an example of a control unit) 30, a ROM (an example of a non-volatile memory) 31, an SDRAM (synchronous dynamic RAM) 32, an NVRAM (non-volatile RAM) 33, And a timer 36.

  The image forming unit 10 forms an image based on the data received by the network interface 20 in accordance with an instruction from the CPU 30, and prints the formed image on paper.

  The operation unit 34 includes a plurality of buttons, and various input operations such as a print request can be performed by the user. The display unit 35 includes a liquid crystal display and a lamp, and can display various setting screens and operation states.

  The control board 5 has, as operation modes, a normal operation mode and a power saving operation mode that consumes less power than in the normal operation mode, and processes related to printing in accordance with a print command from the PC 40 or the operation unit 34. I do.

  The SDRAM (an example of the first volatile memory) 32 includes a work area 32A and other areas (for example, a buffer for the network interface 20) 32B. The work area 32A includes a program area and a heap area. , And a stack area.

  The ROM 31 stores various programs for controlling the operation of the printer 1 such as print processing described later. In addition, the ROM 31 stores an interrupt routine used when returning from the power saving operation mode to the normal operation mode.

The CPU 30 controls the operation of the printer 1 while storing the processing result in the SDRAM 32 or the like according to the program read from the ROM 31. The CPU 30 includes a cache memory 30A that temporarily stores data and an internal RAM (an example of a second volatile memory) 30B for efficient control. The internal RAM 30B has a smaller storage capacity than the SDRAM 32, and may be provided in the CPU 30 as necessary.
The timer 36 measures various times related to the printing process, for example, measures the time for determining the timing for shifting from the normal operation mode to the power saving operation mode.

  The network interface 20 includes a LAN controller (an example of a communication unit) 21, a LAN cable socket 22, and the like, and is connected to an external PC 40 via a LAN cable 38 and a communication line 37. Enables data communication.

  The LAN controller 21 includes a well-known PHY (Physical layer) processing unit and MAC (Media Access Control) frame processing unit (not shown), and has a well-known Wake_on_LAN function (an example of a predetermined function). When the Wake_on_LAN function is set in the LAN controller 21, only the PHY processing unit and the MAC frame processing unit on the reception side are enabled, and the operation state is changed from the normal mode to the standby (standby) state.

2. SDRAM Refresh Control in Power Saving Operation Mode With reference to FIGS. 2 and 4, refresh control of the SDRAM 32 in the power saving operation mode (hereinafter simply referred to as “power saving mode”) of the control board 5 will be described. FIG. 2 is a flowchart showing a process related to the refresh control of the SDRAM 32 by the CPU 30. The CPU 30 executes this process according to a program stored in the ROM 31.

  In step S10 of FIG. 2, the CPU 30 performs a refresh operation on all areas of the SDRAM 32 at predetermined intervals in a normal operation mode (hereinafter simply referred to as “normal mode”). Next, in step S15, it is determined whether or not there is a request for the CPU 30 to shift to the power saving mode. If there is no request for shifting to the power saving mode, the processes of step S10 and step S15 are repeated.

  On the other hand, if it is determined in step S15 that there is a request for shifting to the power saving mode, the process proceeds to step S20. For example, as shown in FIG. 4, the request to shift to the power saving mode is performed when the timer 36 that starts counting from the end of printing (see time t0 in FIG. 4) waits for a predetermined time, for example, 5 minutes. This is performed at time t1 (when time is up) in FIG. In other words, the timer 36 generates a shift request signal for shifting to the power saving mode when the next print request is not received from the PC 40 even after a predetermined time, for example, 5 minutes elapses after the printing process is completed. Then, a transition request signal is supplied to the CPU 30 (see time t1 in FIG. 4). When the CPU 30 receives the transition request signal, the operation mode of the control board 5 is shifted from the normal mode to the power saving mode. The request for shifting from the normal mode to the power saving mode is not limited to this. For example, a shift request can be made by a command from the operation unit 34 of the printer 1 by the user.

  In step S20, the CPU 30 reserves in advance a variable area for an interrupt routine stored in the ROM 31 for returning from the power saving mode to the normal mode in the cache memory 30A and / or the internal RAM 30B in the CPU 30 in advance.

  Also, the position of the variable area for the interrupt routine, that is, the memory address is stored. Specifically, for example, a pointer variable is prepared in the program, and the address of the cache 30A and / or the address of the RAM 30B in which “saved data” or “reserved variable” is stored are stored in the variable. In this embodiment, a variable area for an interrupt routine is reserved in the cache memory 30A.

Next, in step S25, the CPU (an example of a refresh prohibition unit) 30 refreshes only the work area 32A of the SDRAM 32 (see time t1 in FIG. 4). In step S30, it is determined whether or not there is an access to the SDRAM 32, that is, whether or not the program is operated only by the variables in the cache memory 30A in the CPU 30. If there is still access to the SDRAM 32, the processing of step S25 and step S30 is repeated (corresponding to time t1 to time t2 in FIG. 4).
In step S25, it is not limited to refreshing only the work area 32A, and areas other than the work area 32A may be refreshed. In other words, refreshing may be prohibited except at least the work area 32A.

  On the other hand, if it is determined in step S30 that there is no access to the SDRAM 32, in step S35, the CPU (an example of a saving unit) 30 stores the variable data currently existing in the heap area and stack area in the work area 32A. The data is saved in the cache memory 30A and / or the internal RAM 30B in the CPU 30, and the save position (address) is stored. In this embodiment, the data is saved in the cache memory 30A. The retraction position is stored using, for example, the pointer variable.

  In step S40, the CPU 30 completely stops the refresh operation for the SDRAM 32 (see time t2 in FIG. 4). Next, in step S45, the CPU 30 determines whether or not there is a request for transition to the normal mode. If there is no request for transition to the normal mode, the process of step S45 is repeated.

  On the other hand, if there is a request for shifting to the normal mode, in step S50, the CPU (an example of a writing unit) 30 stores the variable data saved in the cache memory 30A as the work area 32A (heap area and To the stack area). That is, the CPU 30 uses the interrupt routine stored in the ROM 31 and the variable area for the interrupt routine reserved in the cache memory 30A in the CPU 30 to reset the SDRAM 32, that is, to set the refresh operation. The request for transition to the normal mode is generated by, for example, an external interrupt (reception of a magic packet by the LAN controller 21) due to a print request from the PC 40 (see time t3 in FIG. 4). Alternatively, it is generated by a print command from the operation unit 34 of the printer 1 by the user.

  In step S55, the variable data existing in the heap area and the stack area saved in the cache memory 30A is returned to the SDRAM 32. Then, returning to step S10, the SDRAM 32 is caused to perform a normal refresh operation.

3. Operation of LAN Controller in Power Saving Mode With reference to FIGS. 3 and 4, the operation of the LAN controller 21 in the power saving mode will be described. FIG. 3 is a flowchart showing processing related to the power saving operation of the LAN controller 21.

  In step S110, the CPU (an example of a communication control unit) 30 operates the LAN controller 21 in the normal mode, that is, in a state where the Wake_on_LAN function is released (corresponding to time t0 to time t1 in FIG. 4). In step S120, as in step S15 of FIG. 2, it is determined whether or not there has been a request to shift the control board 5 to the power saving mode. If there is no request for shifting to the power saving mode, the processes in steps S110 and S120 are repeated.

  On the other hand, if the CPU 30 determines in step S120 that there has been a request to shift to the power saving mode, the process proceeds to step S130. The request for shifting to the power saving mode is made based on, for example, a shift request signal from the timer 36 as in the case of FIG. That is, here, if the next print request is not received from the PC 40 even if a predetermined time, for example, 5 minutes elapses after the print processing is completed, a request for shifting to the power saving mode is generated (time in FIG. 4). see t1).

  Then, in step S130, the CPU 30 sets the Wake_on_LAN function for the LAN controller 21 and puts the LAN controller 21 in a standby state. As a result, in the LAN controller 21, only the PHY processing unit and the MAC frame processing unit on the receiving side are enabled. That is, when the Wake_on_LAN function is set, all functions (corresponding to the “predetermined function” in the present invention) other than the PHY processing unit and the MAC frame processing unit on the receiving side are invalidated. Therefore, in the standby state of the LAN controller 21, power consumption is reduced compared to the normal mode.

  Next, in step S140, the CPU 30 determines whether or not there is a request for transition to the normal mode from other than the LAN controller 21. When there is a request for transition to the normal mode from a device other than the LAN controller 21, for example, when there is a print command from the operation unit 34 of the printer 1 by the user, the CPU 30 instructs the LAN controller 21 in step S150. Cancels the setting of the Wake_on_LAN function. That is, all the functions that have been disabled are enabled except for the PHY processing unit and the MAC frame processing unit on the receiving side. Then, the process returns to step S110, and the LAN controller 21 is operated in the normal mode (see time t3 in FIG. 4).

  On the other hand, in step S140, when there is no request for transition to the normal mode from other than the LAN controller 21, the process proceeds to step S160. In step S160, the LAN controller 21 determines whether a magic packet (an example of validation data) has been received from the outside (LAN), for example, the PC 40. If no magic packet has been received, the process returns to step S140. In this embodiment, the PC 40 adds a magic packet to the print data, and transmits the print data with the magic packet added to the LAN controller 21 via the LAN cable 38 and the communication line 37.

  On the other hand, when the magic packet is received, in step S170, the LAN controller 21 cancels the setting of the Wake_on_LAN function by itself and issues (transmits) a system (control board) return request to the CPU 30. That is, the LAN controller 21 cancels the setting of the Wake_on_LAN function in response to reception of the print data with the magic packet added, that is, all the invalidated items other than the PHY processing unit and the MAC frame processing unit on the receiving side. Is enabled, and its standby state is released (see time t3 in FIG. 4).

  Then, returning to step S110, the LAN controller 21 operates in the normal mode. The CPU 30 performs a process of returning the control board system to the normal mode in response to the control board return request from the LAN controller 21. For example, the refresh operation setting is performed for the SDRAM 32. That is, in this case, the “system return request” corresponds to the “request for transition to the normal mode” in step S45 of FIG.

4). Effects of the embodiment In the present embodiment, in the power saving mode of the control board 5, the refresh operation for the SDRAM 32 is prohibited except for the work area 32A. Further, after the variable data existing in the heap area and the stack area in the work area 32A is saved in the cache memory 30A, the refresh operation for the SDRAM 32 is completely prohibited. Therefore, the power consumption of the control board 5 during the power saving operation is suitably suppressed.

  In addition, in the power saving mode of the control board 5, by setting the Wake_on_LAN function of the LAN controller 21, only the reception-side PHY processing unit and MAC frame processing unit of the LAN controller 21 are enabled. Therefore, the power consumption of the control board 5 is further suppressed.

  Furthermore, by suppressing the power consumption of the control board 5, the power consumption of the printer 1 can also be reduced.

<Other embodiments>
The present invention is not limited to the embodiments described with reference to the above description and drawings. For example, the following embodiments are also included in the technical scope of the present invention.

  (1) In the above embodiment, an example in which both the refresh operation stop process of the SDRAM and the Wake_on_LAN setting process of the LAN controller 21 are performed in the power saving mode is shown. However, only one of the processes is performed in the power saving mode. You may make it perform.

  (2) In the above embodiment, the refresh of only the work area 32A may be performed as shown in the flowchart of FIG. 5 without stopping the refresh of the SDRAM 32 in the entire area. That is, in FIG. 5, the processes of step S20, step S30, step S35, and step S55 shown in FIG. 2 are omitted. Further, the process of step S55 is replaced with the process of step S60. In step S60, the CPU 30 performs resetting using data in the SDRAM 32. That is, the CPU 30 performs a refresh operation setting for the SDRAM 32 using the interrupt routine stored in the SDRAM 32 and the stack area in the SDRAM 32.

  In this case, since only the work area 32A is refreshed in the power saving mode, the power consumption is reduced and the return time from the power saving mode to the normal mode is shortened as compared with the processing of FIG. That is, it is more advantageous than the processing of FIG. 2 when the request for the return time from the power saving mode to the normal mode is severe.

  (3) In the above embodiment, when a magic packet is received, the LAN controller 21 cancels the Wake_on_LAN setting by itself and issues a system return request to the CPU 30, but this is not limitative. Absent. For example, as shown in step S165 of the flowchart of FIG. 6, the LAN controller 21 determines whether the LAN cable 38 is connected to the LAN cable socket 22 and determines that the LAN cable 38 is connected. The Wake_on_LAN setting may be canceled by itself and a system return request may be issued to the CPU 30. The flowchart of FIG. 6 differs from the flowchart of FIG. 3 only in that step S160 of the flowchart of FIG. 3 is replaced with step S165 of the flowchart of FIG.

  In this case, even when the LAN controller 21 cannot receive a magic packet from the outside (PC 40 or the like) (when the PC 40 cannot transmit a magic packet), it can return from the power saving mode to the normal mode. . The determination (detection) that the LAN cable 38 is connected is made, for example, by determining the communication link with the PC 40 by the PHY processing unit and the MAC frame processing unit of the LAN controller 21 when the LAN cable 38 is connected. Done.

  (4) Although an example in which the control board 5 is provided in the printer 1 has been shown, the present invention is not limited to this, and the control board according to the present invention can be applied to any apparatus that requires the power-saving mode operation of the control board.

1 is a block diagram showing a schematic electrical configuration of a printer including a control board according to an embodiment of the present invention. Flow chart of processing related to power saving of SDRAM Flowchart of processing related to power saving of LAN controller Time chart showing transition of operation mode of control board Flow chart of another power saving process of SDRAM Flow chart of another power saving process of the LAN controller

Explanation of symbols

1 ... Printer (image forming apparatus)
5 ... Control board 10 ... Printing section (printing means)
20 ... Network IF (communication part)
21 ... LAN controller (communication unit, detection unit)
22 ... LAN cable socket 30 ... CPU (control unit, refresh prohibition unit, save unit, writing unit, communication control unit)
30A ... Cache memory 30B ... CPU internal RAM (second volatile memory)
31 ... ROM (non-volatile memory)
32 ... SDRAM (first volatile memory)
32A ... Work area 32B ... Buffer area 36 ... Timer 38 ... LAN cable

Claims (11)

A control board having a normal operation mode and a power saving operation mode and performing a predetermined process,
A non-volatile memory for storing the program;
A control unit that reads the program from the nonvolatile memory and executes the predetermined process;
A first volatile memory having a work area used when the control unit executes the predetermined process;
In the power saving operation mode, a refresh prohibiting unit for prohibiting refreshing except for at least the work area among all the areas of the first volatile memory;
With a control board. The control board according to claim 1,
A cache memory and / or a second volatile memory having a smaller storage capacity than the first volatile memory;
When the program operates only with predetermined data stored in the cache memory and / or the second volatile memory, the data in the work area of the first volatile memory is transferred to the cache memory and / or Or a saving unit for saving to the second volatile memory;
A writing unit for writing the saved data to the work area of the first volatile memory when returning from the power saving operation mode to the normal operation mode;
Further comprising
The refresh prohibiting unit prohibits refresh of the entire area of the first volatile memory in the power saving operation mode in response to saving of data in the work area. The control board according to claim 1 or 2,
An image forming unit that forms an image in accordance with an instruction of the control unit of the control board;
An image forming apparatus. A non-volatile memory for storing a program; a control unit for reading the program from the non-volatile memory and executing a predetermined process; and a work area used when the control unit executes the predetermined process. A control board power saving method comprising a volatile memory, having a normal operation mode and a power saving operation mode, and performing a predetermined process,
In the power saving operation mode, a control board power saving method including a prohibiting step of prohibiting refresh except for at least the work area in all areas of the first volatile memory. The control board power saving method according to claim 4, wherein the control board further includes a cache memory and / or a second volatile memory having a smaller storage capacity than the first volatile memory,
The nonvolatile memory for returning to the cache memory and / or the second volatile memory in advance from the power saving operation mode to the normal operation mode when shifting from the normal operation mode to the power saving operation mode. Reserving a variable area for an interrupt routine stored in a memory, and storing a position of the variable area;
In the power saving operation mode, when the control unit operates according to the program using a variable stored in the cache memory and / or the second volatile memory, the first volatile memory Saving the variable data in the work area in the cache memory and / or the second non-volatile memory and storing the saving position;
Subsequent to the evacuation step, a stop step of completely stopping refresh for the first volatile memory;
Resetting to reset the refresh operation for the first volatile memory using the interrupt routine and the variable area for the interrupt routine when returning from the power saving operation mode to the normal operation mode Process,
A return step of returning data in the work area of the first volatile memory saved in the cache memory and / or the second volatile memory to the work area when returning to the normal operation mode;
Further included. Volatile memory having a non-volatile memory for storing a program, a control unit for reading the program from the non-volatile memory and executing a predetermined process, and a work area used when the control unit executes the predetermined process A power saving method for a control board that includes a memory and performs predetermined processing in a normal operation mode and a power saving operation mode,
A prohibiting step of prohibiting a refresh operation by excluding at least the work area out of all areas of the volatile memory in the power saving operation mode by the control unit;
When returning from the power saving operation to the normal operation mode, the interrupt routine stored in the volatile memory and the stack area belonging to the work area in the volatile memory are used to store the volatile memory. A resetting process for resetting the refresh operation,
Including a power saving method for a control board. A control board including a communication unit for communicating data, and operating in a normal operation mode and a power saving operation mode;
An image forming unit that forms an image based on data received by the communication unit;
A communication control unit that controls the communication unit in a standby state that disables a predetermined function included in the communication unit and enables validation data that enables the disabled predetermined function in the power saving operation mode; ,
An image forming apparatus. The image forming apparatus according to claim 7.
A detecting unit for detecting whether or not connection means for communicating the print data with the outside is connected to the communication unit so as to be capable of electrical communication;
The communication control unit controls the communication unit to the standby state regardless of whether or not the power saving operation mode is detected when connection of the connection unit is not detected.
When the connection of the connection means is detected, the communication unit activates the predetermined function and cancels the standby state. A control unit that includes a communication unit that communicates data, and that operates in a normal operation mode and a power saving operation mode; and an image forming apparatus that performs image formation processing based on print data received by the communication unit. A power saving method,
Including a control step of controlling the communication unit in a standby state in which the predetermined function included in the communication unit is disabled and enabling data for enabling the disabled predetermined function can be received in the power saving operation mode. , Power saving method for control board. In the power-saving method of the control board of Claim 9,
An additional step of adding the validation data to the print data;
A transmission step of transmitting the print data to which the validation data is added to the communication unit;
In the communication unit, in response to the reception of the print data to which the validation data is added, the release function that activates the predetermined function and cancels the standby state;
A method for reducing the power consumption of the control board. In the power-saving method of the control board of Claim 9,
A detection step of detecting whether or not a connection means for communicating the print data with the outside is connected to the communication unit so as to be capable of electrical communication;
When the connection of the connection means has not been detected, regardless of whether or not the power saving operation mode, the standby step of setting the communication unit in the standby state,
In the communication unit, when the connection of the connection means is detected, a release step of enabling the predetermined function and releasing the standby state;
A method for reducing the power consumption of the control board.

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