JP2013018238A - Data processing apparatus and controlling method thereof - Google Patents

Abstract

PROBLEM TO BE SOLVED: To update a predetermined elapsed time period without deteriorating a power saving effect with a simple configuration.SOLUTION: An interruption signal to a CPU 101 is input when a timer 103 times a predetermined time period in the case where the CPU 101 is in a halting state. Thus, the halting state of the CPU 101 is released, and the CPU causes a system clock stored in a RAM 104 to update and updates the elapsed time period. The CPU 101 is shifted to the halting state again after completing the update operation accordingly.

Description

  The present invention relates to a data processing apparatus that performs timing and a control method thereof.

  2. Description of the Related Art Conventionally, in a data processing device that operates on a computer such as a CPU (Central Processing Unit), in order to reduce power consumption, there is a method that shifts to a power saving mode in which the CPU is stopped when the user does not operate for a certain period of time. It has been. When the CPU is stopped, only the interrupt instruction is waited and software processing cannot be executed, but a high effect of reducing power consumption is expected. Once the CPU is released from the stopped state, the CPU remains released from the stopped state until no operation is performed again for a certain period of time or until the user instructs the shift to the power saving mode.

  Among such data processing apparatuses, those that perform predetermined processing periodically or at a specific time are known. Therefore, the data processing apparatus needs to keep time, but cannot keep time when the CPU is stopped as described above.

  On the other hand, an RTC (Real Time Clock) is known as a device that can keep measuring the current time even when the CPU is stopped. The RTC has a battery and can keep counting the current time while the CPU is stopped. In Patent Document 1, the current time is measured by the RTC while the CPU is stopped, and the CPU is released from the stopped state when a predetermined time is reached.

JP 2002-300369 A

  However, RTCs are also relatively expensive and relatively large in size. Accordingly, when the RTC is provided in the data processing apparatus, the cost is increased, and a space for attaching the RTC is required, resulting in an increase in the size of the apparatus.

  The present invention has been made in view of the above problems, and provides a data processing apparatus and a control method thereof capable of updating a predetermined elapsed time without impairing the power saving effect with a simple configuration. is there.

  In order to solve the above problems, a data processing apparatus of the present invention is a data processing apparatus that has at least one CPU and executes processing by the CPU, a storage unit that stores a predetermined elapsed time, and the CPU A timer that counts time even when the timer is stopped, and a canceling unit that cancels the stopped state of the CPU when the timer counts a predetermined time. The CPU includes the canceling unit. When the stop state is released by the above, the elapsed time stored in the storage means is updated based on the time measurement result by the timer, and the transition to the stop state is made after the end of the update.

  According to the present invention, when the timer counts a predetermined time, the CPU is released from the stop state and the elapsed time is updated, and after the update is completed, the transition to the stop state is made again. The elapsed time can be updated without losing the effect.

It is a block diagram which shows the structure of an image processing apparatus. It is a flowchart which shows the flow of a process by an image processing apparatus.

  Hereinafter, an example of an embodiment for carrying out the present invention will be described with reference to the drawings.

  FIG. 1 is a block diagram illustrating a configuration of an image processing apparatus 100 that is one embodiment of a data processing apparatus. The image processing apparatus 100 is operated by an external power source or a built-in battery. When the main power is turned on, the image processing apparatus 100 supplies power to each part of the apparatus. However, when the image processing apparatus 100 shifts to the power saving mode, the power supply for some components is turned off and the power consumption is reduced. Transition.

  The CPU 101 controls the operation of the image processing apparatus 100 by loading a program stored in the ROM 105 into the RAM 104 and executing it. In the normal mode, the CPU 101 operates at a constant frequency according to the clock for the CPU 101. In the power saving mode, the CPU 101 stops its operation by stopping the clock for the CPU 101. When the operation of the CPU 101 is stopped, the program executed by the CPU 101 is also stopped. However, the CPU 101 can accept an interrupt signal even in the power saving mode. In addition, the power saving mode is provided in a plurality of stages. In the mode that gives the most power saving effect, the operation of the CPU 101 is stopped as described above, and in the mode that suppresses the power saving effect, the frequency when the CPU 101 operates is lowered. Thus, the operation speed may be decreased. In the following, a case where the CPU 101 stops operation and waits for an interrupt signal is described as a power saving mode.

  The ASIC 102 is hardware for executing a specific process for the operation of the image processing apparatus 100, and includes a timer 103 for timing. The ASIC 102 generates an interrupt signal to the CPU 101 at regular intervals according to the timing of the timer 103. The ASIC 102 generates an interrupt signal at a timing preset by the CPU 101. The CPU 101 makes the interval for generating the interrupt signal longer when the image processing apparatus 100 is operating in the power saving mode than when the image processing apparatus 100 is operating in the normal mode. Although the timer 103 can measure time even in the power saving mode, the power required for operation is smaller and smaller than the RTC. The timer 103 does not measure the current time, but simply measures the elapsed time.

  The ROM 105 stores various information for the operation of the image processing apparatus 100 in addition to the program executed by the CPU 101. The RAM 104 is used as a work area for the CPU 101 and stores various information for the operation of the image processing apparatus 100. In addition, the RAM 104 stores a system clock value indicating an elapsed time after the image processing apparatus 100 is activated. The CPU 101 updates the value of the system counter.

  The print engine unit 106 performs processing for printing an image on a recording medium based on the input image data. The print engine unit 106 generates a signal indicating dot on / off based on the input image data, and controls the drive motor 107 to apply the recording agent while scanning the head 108 on the recording medium, thereby generating an image. Let it print. The head 108 has a plurality of nozzles that eject ink, which is a recording agent, and prints an image on a recording medium by ejecting ink from the nozzles in accordance with a signal indicating dot ON from the print engine unit 106. The print engine unit 106 can execute a print job for printing an image based on image data sent from an external device connected to the image processing apparatus 100. The thermistor sensor 109 measures the environmental temperature near the head 108. The CPU 101 writes the environmental temperature information measured by the thermistor sensor 109 into the RAM 104.

  When the head 108 has not ejected ink for a certain period, it is necessary to perform a recovery operation (maintenance process) in order to prevent nozzle clogging and the like. The head 108 needs to change the recovery operation timing, ink ejection control, and the like according to the environmental temperature. The time on the system clock when the head 108 has ejected ink last is stored in the RAM 104 and is updated each time ink ejection processing is performed.

  The scanner engine unit 110 performs processing for reading an image on a document. The scanner engine unit 110 controls the driving motor 111 to cause the reading sensor to read an image on the document while scanning the document placed on the document table, and generates image data corresponding to the image. By supplying image data obtained by causing the scanner engine unit 110 to read an image on a document to the print engine unit 106, the document can be copied (copy job). A scan job for transmitting image data read by the scanner engine unit 110 to an external apparatus connected to the image processing apparatus 100 can also be executed.

  When the image processing apparatus 100 shifts to the power saving mode, the power supplied to the drive motors 107 and 110 is turned off.

  The operation unit 112 receives an instruction from the user. The operation unit 112 includes a key group for a user to input an instruction and a display unit that displays information to be provided to the user. When the image processing apparatus 100 shifts to the power saving mode, the power supplied to the operation unit 112 is turned off, and the display unit is turned off. Even if the operation mode is shifted to the power saving mode, the operation unit 112 accepts an operation by the key group. When any key group is operated during the power saving mode, an interrupt signal is input to the CPU 101 and the operation mode is shifted to the normal mode. When the key group of the operation unit 112 is not operated for a predetermined period, the image processing apparatus 100 shifts to the power saving mode. The image processing apparatus 100 can be shifted to the power saving mode by a predetermined key operation of the operation unit 112.

  An interface 113 connects the image processing apparatus 100 to an external device. Image data sent from an external device connected via the interface 113 can be supplied to the print engine unit 106 to print an image on a recording medium. Further, the image processing apparatus 100 can shift to the power saving mode and shift to the normal mode in accordance with an instruction sent from an external apparatus via the interface 113.

  When the main power is turned on, the image processing apparatus 100 loads the control program stored in the ROM 105 into the RAM 104, and the CPU 101 executes the control program. Then, the CPU 101 sets the system clock value stored in the RAM 104 to zero. Then, the CPU 101 temporarily starts based on the interrupt signal from the ASIC 102 while the operation is stopped in the power saving mode, and reflects (adds) the time measurement result of the timer 103 to the value of the system clock. Then, the CPU 101 cancels the power saving mode when the value of the system clock reaches a preset value, shifts to the normal mode, and executes processing. Further, the CPU 101 receives an interrupt signal from the ASIC 102 and, when activated, acquires information on the environmental temperature measured by the thermistor sensor 109. Then, the time until returning to the normal mode is changed according to the acquisition result, and the parameters for controlling the head 108 are changed.

  Next, in the image processing apparatus 100 having the above-described configuration, a process flow when the conditions for shifting to the power saving mode are satisfied and the mode is shifted to the power saving mode will be described. FIG. 2 is a flowchart showing the flow of this process. This flowchart is a process performed when the CPU 101 loads a control program stored in the ROM 105 to the RAM 104 and executes it, and a process performed while the program is stopped according to the conditions set in a predetermined register in the image processing apparatus 100. is there. This flowchart is a process for ensuring the operation of the head 108 even when the mode is shifted to the power saving mode.

  Conditions for shifting to the power saving mode include that the operation by the operation unit 112 has not been performed for a certain period of time, or that no signal has been received via the interface 113 for a certain period of time. Also included is that the print engine unit 106 is not operating for a certain period and the scanner engine unit 110 is not operating for a certain period. Also included is an instruction to shift to the power saving mode via the operation unit 112 or the interface 113. When any of these conditions is satisfied, the flowchart of FIG. 2 is started.

  In step 101, the CPU 101 cancels the timing setting for causing the ASIC 102 to output an interrupt signal in the normal mode. Also, the setting of conditions for causing the CPU 101 to perform an interrupt in the normal mode is canceled. In step 102, conditions for causing the CPU 101 to perform an interrupt in the power saving mode are set. The conditions for causing an interrupt in the power saving mode are conditions for shifting from the power saving mode to the normal mode, and include a case where a predetermined signal is received via a predetermined operation by the operation unit 112 or the interface 113. . The conditions also include that the elapsed time from the last ejection of ink by the head 108 stored in the RAM 104 has exceeded a predetermined time, and that the environmental temperature has exceeded a predetermined range. Conditions for these interrupts are registered (set) in a predetermined register, and an interrupt signal is input to the CPU 101 when the image processing apparatus 100 is in a state meeting any of these conditions.

  In step 103, the CPU 101 turns off the power supply to predetermined locations such as the operation unit 112 and the drive motors 107 and 111.

  In step 104, the CPU 101 sets the timing at which the ASIC 102 outputs an interrupt signal in the power saving mode. Here, for example, the timer 103 is set to output an interrupt signal every time it measures 500 milliseconds. Note that the timing set here is such that if the interval is too short, the frequency of activation of the CPU 101 increases, and if it is too long, an error is likely to occur. Therefore, an appropriate timing is set in consideration of these. In step 105, the ASIC 102 is instructed to start the timer 103.

  Then, the CPU 101 stops the clock for the CPU 101 for operating itself and stops its own operation. As a result, the CPU 101 receives only an interrupt signal and waits for an interrupt signal corresponding to the condition set in step 102. Until the interrupt signal corresponding to the condition is detected in step 107, the stopped state of the CPU 101 is maintained.

  When an interrupt signal is detected in step 107, the process proceeds to step 108, the CPU 101 is released from the clock stop state, and the program can be executed. However, here, the CPU 101 only transitions to the operation state, the power supply to the operation unit 112 and the drive motors 107 and 111 is maintained in a stopped state, and the power saving mode is continued.

  In step 109, it is determined under which conditions the interrupt signal detected in step 107 is generated, that is, the type of interrupt. If it is determined that the interrupt is due to the timer 103 reaching the timing set in step 104, the process proceeds to step 110. If it is determined that the interrupt is due to a factor other than the timer, step 116 is performed. Proceed to

  In step 110, the ASIC 102 is instructed to restart the timer 103. In step 111, the time set in step 104 is added to the value of the system clock stored in the RAM 104 to be updated. Here, since it is set to generate an interrupt signal every 500 milliseconds, 500 milliseconds is added. In step 112, the print engine unit 106 is notified that the system clock has been updated. The reason why the print engine unit 106 is notified that the system clock has been updated is that this flow is processing for ensuring the operation of the head 108. In step 113, the elapsed time from the previous ink ejection by the head 108 is calculated. The previous ink ejection includes printing by a received print job, recovery operation, and the like. This may be only the previous recovery operation. The print engine unit 106 that has been notified that the system clock has been updated acquires the measurement result of the environmental temperature by the thermistor sensor 109 and notifies the CPU 101 of the result. In step 114, the measurement result of the ambient temperature of the thermistor sensor 109 notified from the print engine unit 106 is acquired. In step 115, the CPU 101 stores the elapsed time calculated in step 113 and the environmental temperature acquired in step 114 in the RAM 104.

  Then, the process proceeds to step 106 in response to the end of information storage in step 115, the CPU 101 is again stopped, and thereafter the same processing in steps 106 to 115 is periodically performed, and the system clock is sequentially updated. Here, since the CPU 101 is activated for a short period from S110 to S115, the power consumption is not so much. When the environmental temperature acquired in step 114 exceeds a predetermined range, the condition set in step 102 may be changed, or the timing set in step 104 may be changed.

  If it is determined in step 109 that the interrupt signal is based on other than the timer 103, the process proceeds to step 116, and the CPU 101 instructs the ASIC 102 to stop the timer 103. In step 117, the CPU 101 adds the time measurement result of the timer 103 at this time to the value of the system clock in the RAM 104 and updates it.

  In step 118, power supply to the operation unit 112 and the drive motors 107 and 111 is turned on. In step 119, the interrupt setting for the power saving mode set in step 102 is canceled. In step 120, the interrupt for the normal mode is set.

  The CPU 101 shifts the image processing apparatus 100 to the normal mode when the processes in the above steps 116 to 120 are completed. Then, after shifting to the normal mode, the CPU 101 continues to execute the program. In the normal mode, a normal print job by the print engine unit 106, a copy job in which the scanner engine unit 110 and the print engine unit 106 are linked, and a scan job by the scanner engine unit 110 can be executed. Further, when the condition for shifting to the normal mode is the time when the elapsed time stored in the RAM 104 needs to be restored (maintenance processing), the mode is shifted to the normal mode and the recovery operation is executed. That is, the CPU 101 causes the print engine unit 106 to execute an ink ejection process from the head 108.

  In the above processing, the system clock is updated even in the power saving mode in order to perform the recovery operation of the head 108 at an appropriate timing. However, other processing performed when a predetermined elapsed time is reached. You may make it apply to.

  Moreover, you may apply to the some process which should be performed in different elapsed time. In this case, an elapsed time stored in the RAM 104 may be provided for each processing content, and the mode may be shifted to the normal mode according to each elapsed time. A plurality of system clocks may be provided.

  In the above example, the system clock is updated and the elapsed time is updated. However, only one of them may be provided. Further, the elapsed time is not limited to the internal RAM but may be an external memory or the like.

  In the above example, the image processing apparatus 100 does not measure the current time. However, the current time may be measured using the mechanism of the above example. When the main power supply of the image processing apparatus 100 is turned on, the user may input the current time from the operation unit 112, and thereafter, the time measurement result by the timer 103 may be added. Further, the current time may be acquired from an external device connected via the interface 113, and thereafter, the time measurement result by the timer 103 may be added. Thereby, when there is a process to be performed at a specific time, the process can be executed by shifting from the power saving mode to the normal mode as in the above example.

  In the above example, the image processing apparatus 100 is used as the data processing apparatus. However, other types of apparatuses can be used as long as the CPU is stopped to save power and perform predetermined processing at a predetermined time. There may be.

  According to the embodiment as described above, even if the CPU is stopped in the power saving mode, a process to be performed at a specific timing can be executed. At that time, since the CPU is a short period of processing for updating the elapsed time, the power saving effect is not greatly impaired. In addition, since the timer used for updating the elapsed time can be a simple one that simply counts the elapsed time, the cost can be reduced and the apparatus can be prevented from being enlarged.

  Moreover, this embodiment is implement | achieved also by performing the following processes. That is, software (program) that realizes the functions of the above-described embodiments is supplied to a system or apparatus via a network or various storage media, and a computer (CPU, MPU, etc.) of the system or apparatus reads and executes the program. It is processing to do. Further, the program may be executed by one computer or may be executed in conjunction with a plurality of computers. When performing operation in cooperation with a plurality of computers, the processing of the above embodiment is applied to each computer, or only one of the plurality of computers is applied. Moreover, it is not necessary to implement all of the above-described processing by software, and part or all of the processing may be implemented by hardware.

Claims (6)

A data processing apparatus having at least one CPU and executing processing by the CPU,
Storage means for storing a predetermined elapsed time;
A timer that counts time even when the CPU is stopped; and
A release means for releasing the stop state of the CPU when the timer times a predetermined time;
The CPU updates the elapsed time stored in the storage unit based on the time measurement result by the timer when the stop state is released by the release unit, and transitions to the stop state after the update is completed. A data processing device.   The data processing apparatus according to claim 1, wherein the CPU executes a predetermined process when the elapsed time stored in the storage unit reaches a predetermined time.   The data processing apparatus according to claim 1, wherein the CPU stops power supply to a predetermined location of the data processing apparatus before transitioning to a stop state. A control method for a data processing device having at least one CPU and a timer for measuring time even when the CPU is stopped, and executing processing by the CPU,
Store the specified elapsed time in memory,
When the timer counts a predetermined time, the CPU is released from the stopped state,
The CPU updates the elapsed time stored in the memory based on the time measurement result by the timer when the stop state is released, and transitions to the stop state after the update ends. Control method.   5. The method according to claim 4, wherein the CPU executes a predetermined process when the elapsed time stored in the storage unit reaches a predetermined time. .   6. The method of controlling a data processing apparatus according to claim 4, wherein the CPU stops power supply to a predetermined location of the data processing apparatus before transitioning to the stop state.

Images