JP4991493B2 - Electronic device, power mode switching method, program, and computer-readable recording medium - Google Patents

Description

  The present invention relates to an electronic device capable of reducing power consumption, a power mode switching method, a program, and a computer-readable recording medium storing the program.

  In recent years, in a device connected to a network, such as a printer, scanner, facsimile, or MFP (Multi Function Peripheral) which is a complex machine of these devices, for example, when the device is not operating for a predetermined time, to each part of the device In order to reduce the power consumption and suppress the power cost by cutting off the power supply, the power saving mode (or the energy saving mode) is transferred.

  In the device, when a packet or the like is received and processed in the power saving mode, the power saving mode is canceled, and a transition is made to the normal power mode in which the entire device is energized. Therefore, in order to further reduce power consumption, the power saving mode must be maintained as long as possible.

  Therefore, ARP (Address Resolution Protocol) and PING (Packet Internet Groper) are included in the packet data addressed to the local station so that all the packets need not be processed in the normal power mode even if packets are received. For example, an electronic apparatus that processes a packet of a protocol that can be automatically responded by only a part of hardware without energizing the entire device has been proposed (see Patent Document 1).

  Moreover, in order to lengthen the time for maintaining the power saving mode, it is considered that it is better to shift to the power saving mode as soon as possible after the operation of the device is completed in the normal power mode. If the frequency of use of the device is high, that is, if packets are received immediately after shifting to the power saving mode and shifting to the normal power mode, the number of startups of the device increases and power consumption due to startup increases. Conversely, power may be consumed. Therefore, it is necessary to appropriately set the time until the device shifts to the power saving mode after the operation in the normal power mode is completed.

  As a solution to this problem, there is known a network terminal device that suppresses power consumption by adjusting the time required to shift to the energy saving mode according to the level of congestion of the network calculated from the number of received packets. (See Patent Document 2).

However, in order to further reduce the power consumption, it is necessary to reduce the power consumption of the high power consumption portion of the device configuration, typically the memory.
That is, the memory (for example, SDRAM: Synchronous DRAM) stores data stored in the storage element when the device is in the power saving mode as well as the normal operation mode when the device is in the normal power mode. As an operation mode for maintaining it so as not to be lost, a self-refresh mode and a precharge mode with reduced power consumption are provided. In terms of power consumption, the self-refresh mode is lower than the precharge mode, but the self-refresh mode has a characteristic that activation (transition to the normal operation mode) is slow.

Therefore, in the power saving mode of the device, if only a packet that can be automatically responded by some hardware as described above is received and there is no reception of a packet that requires device activation in response, the minimum power consumption is It is desirable to reduce power consumption by entering a state (self-refresh mode).
On the other hand, when there are many receptions of packets that require device activation in response, that is, when device activation is frequently requested by packet response and the device activation frequency is large, the precharge mode is set and the packet is It is desirable to be able to quickly activate and respond when received.
Japanese Patent Application No. 2007-152151 JP 2006-3332807 A

  An object of the present invention is to further reduce power consumption in a power saving mode in an electronic device having a function of responding to a packet transmitted via a network.

The invention of the present application is an electronic device having a function of responding to a packet transmitted via a network and operable in a normal power mode and a power saving mode, and when a predetermined condition is satisfied, respectively, Control means for shifting from the first power saving mode to the second power saving mode with less power consumption from the first power saving mode, and the automatic response received in the first and second power saving modes Automatic packet response means for responding to possible packets, measurement means for measuring the number of responses of the automatic packet response means in the first power saving mode, and whether or not the number of responses exceeds a preset threshold value Determining means for determining whether or not the control means shifts the device to the second power saving mode when the determining means determines that the number of responses exceeds the threshold. Characterized in that to.
Another invention of the present application is a power mode switching method in an electronic device having a function of responding to a packet transmitted via a network and operable in a normal power mode and a power saving mode, each of which has predetermined conditions. When the above is established, a control step of shifting from the normal power mode to the first power saving mode and shifting from the first power saving mode to the second power saving mode with less power consumption, and the first and second savings, An automatic packet response process for processing a packet that can be automatically responded received in the power mode, a measurement process for measuring the number of responses in the automatic packet response process in the first power saving mode, and the number of responses set in advance A determination step for determining whether or not the determined threshold value has been exceeded, and the control step determines when the number of responses exceeds the threshold value in the determination step. Wherein the shifting the device to a second power saving mode.
Furthermore, another invention of the present application is a program for executing each step in the power mode switching method by a computer and a computer-readable recording medium storing the program.

  According to the present invention, in an electronic device having a function of responding to a packet transmitted via a network, it is possible to further reduce standby power consumption and improve usability of a user device as compared with the conventional device. Can be made.

FIG. 1 is a block diagram of an electronic device according to an embodiment of the present invention.
The electronic device of the present embodiment includes (1) a CPU (Central Processing Unit) 11 that controls the system unit of the electronic device, a memory 12 that is an SDRAM corresponding to a storage device that stores data received from the network, A system unit 1 comprising a memory controller 13 which is a control means for controlling the memory 12,
(2) The packet automatic response unit 17 which is an automatic packet response unit that adds data requested by the transmission source to the received packet and responds (transfers) as it is, and the number of times the packet automatic response unit 17 responds is counted. A packet counter 18 and a packet filter 16 having each means for determining whether or not the received packet data is a packet addressed to its own device, and determining the number of responses described later, measuring the packet interval, and determining the packet interval; A packet processing unit 2 comprising:
(3) PHY 14 that controls the physical layer (Physical Layer) of the network and performs A / D (analog / digital) conversion of data, and MAC (Media Access Controller) that analyzes packets and controls transmission and reception of packet data 15, DMA (Direct Memory Access) 19 a and 19 b for transferring the received packet data directly to the memory 12 without going through the CPU 11, and the system unit 1 side when transmitting data from the electronic apparatus to the outside And a selector 20 for selecting whether to transmit or to transmit from the packet processing unit 2 side.

This electronic device is activated once when the power is turned on, and then has a predetermined power saving transition condition (condition for shifting from the normal power mode to the power saving mode; for example, a system for a certain time without input of processing operation from a user for a certain period of time. If the packet processed by the unit 1 is not received), the power supply from a power source (not shown) is cut off by an appropriate means, and the mode is shifted to the power saving mode in which the power consumption is reduced.
When the mode is shifted to the power saving mode, the CPU 11 stops supplying power, and the memory 12 changes from the normal operation mode (the operation mode when the electronic device is in the normal power mode) to the precharge mode or the self operation mode unique to the memory 12. Transition to refresh mode.
In the present embodiment, the precharge mode is the initial state of the memory 12 in the power saving mode. The transition of the operation mode of the memory 12 is controlled by the memory controller 13.

The precharge mode which is an operation mode of the memory 13 is a mode in which charge is periodically replenished in order to hold data in the memory 13, and when the memory 13 does not execute a read / write operation. By operating in this precharge mode, the power consumption can be reduced more than usual. By operating in this mode, the power consumption of the entire electronic device is reduced (the first power saving mode Say).
On the other hand, the self-refresh mode is a mode in which the same operation as the precharge mode is performed, but the memory 13 itself performs this operation, that is, an access operation from the outside is unnecessary, so that it consumes more than the precharge mode. The power can be reduced, and by operating in the self-refresh mode, the electronic device as a whole is brought into a state where the power consumption is reduced as compared to the first power saving mode (referred to as the second power saving mode).

When the electronic device receives packet data in the power saving mode, the PHY 14 performs A / D conversion on the packet data and transfers the packet data to the MAC 15. The MAC 15 analyzes the packet data and transfers it to the packet filter 16.
The packet filter 16 compares the destination MAC address and destination IP address included in the packet data analyzed by the MAC 15 with the destination MAC address and destination IP address of its own device stored in advance in storage means such as a register (not shown), It is determined that the packet data is not addressed to its own device, that is, a broadcast packet to another device or a multicast packet, and the packet data is discarded. Of the packet data addressed to the own device, packet data that can be automatically answered is transmitted to the packet automatic response unit 17, and the packet automatic response unit 17 processes the packet while maintaining the power saving mode.
On the other hand, packet data that cannot be automatically answered is transmitted to the system unit 1, and after being shifted to the normal power mode, processed in the system unit 1.

The packet automatic response unit 17 transmits the packet data to which the response data is added to the selector 20 and transmits an active signal to the selector 20 so that the selector 20 selects the packet data from the packet automatic response unit 17.
Note that the selector 20 normally selects a transmission packet from the system unit 1.
The packet data transmitted from the selector 20 is transmitted to the network via the MAC 15 and the PHY 14.

FIG. 2 is a flowchart illustrating a procedure for the electronic apparatus to shift to the power saving mode.
First, when the electronic device is activated (S101) and the network operation is started (S102), the packet filter 16 per unit time, for example, one hour in order to grasp the communication state of the network environment to which the device is connected. The operation of measuring the number of packets received per hit is performed (S103).
Based on the number of packets received per unit time, a threshold value to be set in the packet counter 18 is determined (S104), and the threshold value is set in the packet counter 18 (S105). That is, for example, if the number of packets received from the network per unit time is large, the probability of starting this electronic device increases. Therefore, if the threshold is set high and the number of packets received per unit time is small Since the probability of starting the electronic device is reduced, the threshold value is set low.
Thereafter, when the establishment of a predetermined condition (for example, there is no input of a processing operation from a user for a certain period of time, no reception of a packet to be processed by the system unit 1 for a certain period of time) is detected when the device enters the power saving mode (S106, YES), the device shifts to the power saving mode (S107).
Further, when it is not detected that the predetermined condition for the device to enter the power saving mode is detected (S106, NO), the network operation is continuously performed (S108).

  The threshold value is used for setting the operation mode of the memory in the processing shown in FIGS. 3 and 5 described later. Moreover, this threshold value can be changed and may be arbitrarily set by the user.

  In the present embodiment, the number of times the packet automatic response unit 17 responds to the packet data received by the electronic device that has shifted to the power saving mode is measured, and the number of responses is shown in FIG. When the number of responses exceeds the threshold as compared with the threshold determined in the processing flow, the operation mode of the memory 12 is shifted to the self-refresh mode with less power consumption. When a packet to be processed by the system unit 1 is received and the system unit 1 starts up and shifts to the normal power mode, the measured number of responses is cleared each time (to 0).

FIG. 3 is a flowchart showing the operation after the electronic device shifts to the power saving mode.
When the electronic device shifts to the power saving mode (S201), the memory controller 13 shifts the operation mode of the memory 12 to the precharge mode (S202), and performs a packet reception operation (S203).
When the packet addressed to the local station is received, the packet filter 16 determines whether or not the automatic response by the packet automatic response unit 17 is possible (S204).

If it is determined that automatic packet response is not possible (204, NO), since it is necessary to process the received packet in the system unit 1, the entire apparatus including the system unit 1 is shifted to the normal power mode (S210). Then, a count value (number of responses responded by the automatic response unit 17) to be described later is cleared, the memory 12 is set to the normal operation mode by the memory controller 13 (S211), and the received packet is input to the memory 12 (S212). Next, the CPU 11 reads the received packet from the memory 12 and performs appropriate packet processing (S213).
Thereafter, when it is detected that a predetermined condition for the electronic device to shift to the power saving mode is satisfied (S214, YES), the process returns to step S201. That is, the mode again shifts to the power saving mode (S201), the memory 12 is set from the normal operation mode to the precharge mode (S202), and the packet reception operation is performed (S203).
Further, when the establishment of the condition where the electronic device shifts to the power saving mode is not detected (S214, NO), the network operation is continuously performed (S215).

On the other hand, when the received packet can be automatically answered in step S204 (S204, YES), measurement of the number of responses in the packet automatic response unit 17 is started while maintaining the first power saving mode (S205). That is, every time there is a response from the packet automatic response unit 17, the count is incremented by one.
The packet filter 16 determines the magnitude of this count value and the threshold set in the packet counter 18 (S206). When it is determined that the count value exceeds the threshold (S206, YES), measurement of the number of responses in the packet automatic response unit 17 is stopped (S207), and the memory controller 13 self-refreshes the operation mode of the memory 12. The mode is set (S208). Thereafter, the network operation is continued (S209).
When it is determined that the count value is equal to or smaller than the threshold value (S206, NO), the process is terminated as it is.

With the above processing flow, when the number of automatic responses in the packet automatic response unit 17 exceeds the threshold in the first power saving mode, that is, when the response frequency in the packet automatic response unit 17 is high, By shifting the operation mode from the precharge mode to the self-refresh mode, it is possible to shift to the second power saving mode and further reduce power consumption.
Further, when the device shifts from the normal power mode to the first power saving mode, the operation mode of the memory 12 is set to the precharge mode again. For example, when the electronic device is continuously activated, the activation time is increased. Can be activated in a relatively short precharge mode, and user convenience can be improved.

In the above processing, when the electronic device is activated to process packet data, the automatic response count (count value) of the packet automatic response unit 17 is cleared to 0, and the electronic device shifts from the normal power mode to the power saving mode. The packet counter 18 always starts counting the number of automatic responses from 0.
Further, since the threshold value can be changed by the user, it is possible to control the transition of the memory operation mode in accordance with the user's usage environment and the network environment.

In the electronic device of this embodiment, the operation mode of the memory 12 can be set based on the packet reception interval (the time interval from the reception of one packet to the reception of the next packet). . That is, when the packet reception interval is long, that is, as shown in FIG. 4A, it is considered that the system unit 1 is not frequently started, so the memory 12 is set to the self-refresh mode. On the other hand, when the packet reception interval is short, that is, as shown in FIG. 4B, it is considered that the number of times of activation of the system unit 1 increases, so that the memory 12 operates in the precharge mode in consideration of the activation time of the electronic device. Let
The packet filter 16 measures the packet reception interval.

FIG. 5 is another flowchart showing the operation of the electronic device after shifting to the power saving mode. This processing flow is basically the same as that shown in FIG.
When the electronic device shifts to the power saving mode (S301), the memory 12 shifts to the precharge mode (S302), and a packet reception operation is performed (S303).
When a packet addressed to the own station is received, it is determined whether or not an automatic response by the packet automatic response unit 17 is possible (S304).

When it is determined that an automatic packet response cannot be made (304, NO), the entire apparatus including the system unit 1 is returned (shifted) to the normal power mode (S311), and a count value to be described later is cleared, and the memory 12 Is set to the normal operation mode (S312), and the received packet is input to the memory 12 (S313). Next, the CPU 11 reads the received packet from the memory 12 and performs appropriate packet processing (S314).
Thereafter, when it is detected that a predetermined condition for the electronic device to shift to the power saving mode is satisfied (S315, YES), the process returns to step S301. That is, the mode again shifts to the power saving mode (S301), the memory 12 is set from the normal operation mode to the precharge mode (S302), and the packet reception operation is performed (S303).
In addition, when the establishment of a predetermined condition for the device to enter the power saving mode is not detected (S315, NO), the network operation is continuously performed (S316).

On the other hand, when the received packet is a packet that can be automatically answered in step S304 (S304, YES), measurement of the number of responses in the packet automatic response unit 17 is started while maintaining the power saving mode (S305). That is, the count is incremented by 1 each time a response is made by the packet automatic response unit 17.
The packet filter 16 compares this count value with the threshold set in the packet counter 18 (S306), and when the count value exceeds the threshold (S306, YES), the number of responses in the packet automatic response unit 17 is determined. The measurement is stopped (S307), the memory controller 13 sets the operation mode of the memory 12 to the self-refresh mode (S308), and then the network operation is continued (S309).

In step S306, when the count value is less than the threshold value (S306, NO), it is determined whether the packet interval of the received packet measured by the packet filter 16 is longer than a predetermined interval (step S306). S310).
When it is determined that the packet interval is equal to or less than the predetermined interval (S310, NO), the processing is terminated as it is.
When it is determined that the packet interval exceeds the predetermined interval (S310, YES), the operation mode of the memory 12 is set to the self-refresh mode (S308), and the network operation is continuously performed (S309).

Note that the predetermined interval can be changed, and may be arbitrarily set by the user, or may be automatically set according to the network environment.
In addition, in order to execute the processing described according to the flowchart described above, a computer (information processing apparatus) is caused to read a program describing the procedure of the above processing. The computer program is recorded on a known computer-readable recording medium such as an HDD (hard disk), a CD (compact disk), an FD (flexible disk), or an MO (magneto-optical disk) and installed in the computer. Is possible.

As described above, according to the present embodiment, even if the number of automatic responses by the packet automatic response unit 17 in the power saving mode does not exceed the set threshold, it is determined that the predetermined packet interval has been exceeded. If this happens, it may be determined that there is time before the device is started after receiving the packet, and the memory operation mode is changed from the precharge mode to the self-refresh mode to reduce power consumption of the electronic device. it can.
In this embodiment, the power saving mode of the electronic device is divided into two stages according to the operation mode of the storage device. By doing so, the power saving mode of the electronic device can be similarly set in two stages.

It is a block diagram of an electronic device. It is the flowchart which showed the procedure which transfers to a power saving mode. It is the flowchart which showed the operation | movement after power saving mode transfer. FIG. 4A is a diagram illustrating a state in which the interval between received packets is long, and FIG. 4B is a diagram illustrating a state in which the interval between received packets is short. It is another flowchart which showed the operation | movement after power saving mode transfer.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... System part, 2 ... Packet processing part, 11 ... CPU, 12 ... Memory, 13 ... Memory controller, 14 ... PHY, 15 ... MAC, 16 ... Packet filter, 17 ... automatic packet response unit, 18 ... packet counter, 19a, 19b ... DMA, 20 ... selector.

Claims (8)

An electronic device having a function of responding to a packet transmitted via a network and operable in a normal power mode and a power saving mode,
A control means for shifting from the normal power mode to the first power saving mode and shifting from the first power saving mode to the second power saving mode when the predetermined condition is satisfied; And an automatic packet response means for processing an automatically responsive packet received in the second power saving mode, a measuring means for measuring the number of responses of the automatic packet response means in the first power saving mode, and the response Determining means for determining whether or not the number of times exceeds a preset threshold, and when the determining means determines that the number of responses exceeds the threshold, the control means An electronic device characterized in that it is shifted to a power saving mode. The electronic device according to claim 1,
Means for measuring a packet reception interval, and packet interval determination means for determining whether or not the packet reception interval measured by the interval measurement means exceeds a predetermined threshold, wherein the control means includes the packet interval An electronic device that shifts the power saving mode to the second power saving mode when the determining means determines that the packet interval exceeds the threshold. The electronic device according to claim 1 or 2,
An electronic device having control means for controlling to shift to the normal power mode when a packet addressed to the own device that cannot be automatically responded is received in the first or second power saving mode. The electronic device according to claim 1,
An electronic device that operates a storage device included in the electronic device in a precharge mode in a first power saving mode, and operates the storage device in a self-refresh mode in a second power saving mode. A power mode switching method in an electronic device having a function of responding to a packet transmitted via a network and operable in a normal power mode and a power saving mode,
A control step of shifting from the normal power mode to the first power saving mode and shifting from the first power saving mode to the second power saving mode when the predetermined condition is satisfied; An automatic packet response step for performing response processing on a packet capable of automatic response received in the second power saving mode; a measuring step for measuring the number of responses in the automatic packet response step in the first power saving mode;
A determination step for determining whether or not the number of responses exceeds a preset threshold value, and the control step determines that the apparatus is not used when the determination step determines that the number of responses exceeds the threshold value. A method for switching a power mode in an electronic device, wherein the mode is shifted to a second power saving mode. The method for switching the power mode in the electronic device according to claim 5,
A step of measuring a packet reception interval, and a packet interval determination step of determining whether or not the packet interval measured in the interval measurement step exceeds a predetermined threshold, wherein the control step includes the packet interval determination A method for switching a power mode in an electronic device that shifts a power saving mode to the second power saving mode when it is determined in the step that the packet interval exceeds the threshold.   The program for performing each process of the switching method of the electric power mode described in Claim 5 or 6 with a computer.   A computer-readable recording medium on which the program according to claim 7 is recorded.

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