JP2008262393A - Information processing system and control method thereof - Google Patents

Abstract

The power consumption of the entire information processing system is reduced.
A device status notification unit receives a notification from an optical disc control CPU and notifies an operation status of a device interface unit, a device status detection unit detects a notification from the device status notification unit, The detection result is notified to the host CPU 10. The host CPU 10 controls the operation state of the host interface unit 40 according to the detection result (the operation state of the device interface unit 80), and notifies the host state notification unit 30 of the operation state of the host interface unit 40. The operation status of the host interface unit 40 is notified to the optical disc control CPU 50 via the host status notification unit 30 and the host status detection unit 70.
[Selection] Figure 1

Description

  The present invention relates to an information processing system, and more particularly, to a power management technique for an information processing apparatus having a SerialATA interface.

  Currently, inexpensive ATA (AT Attachment) and ATAPI (AT Attachment Packet Interface) interfaces are widely used as interfaces for external storage devices. In the ATA / ATAPI interface, the operation state of the external storage device is basically shifted to the low power consumption mode by various commands from the host computer. Since this control is performed via the ATA / ATAPI interface, it is difficult to reduce the power consumption of the interface portion.

In order to solve this problem, Japanese Patent Laid-Open No. 2002-318646 (Patent Document 1) states that data is not exchanged between a host computer and an optical disk drive connected via an ATA / ATAPI interface. When the optical disk drive goes into a sleep mode at its own discretion when it lasts for a predetermined time or longer, the power consumption of the interface unit is reduced (here, the interface unit stops and cannot be accessed) Means state.) Further, when the sleep mode is entered, the optical disc drive cannot receive a command via the interface unit. Therefore, when the optical disk drive is restored, the power supply to the optical disk drive is started by supplying the hardware reset signal from the host computer directly to the state processing unit without going through the interface unit. As a result, the optical disk drive can be restored with the power supply to the interface unit stopped.
JP 2002-318646 A

  However, in the information processing device disclosed in Patent Document 1, since the interface unit is stopped after the optical disk drive is in the sleep mode, the host computer is in a state of the optical disk drive (whether the interface unit is stopped). Cannot be recognized. Further, the optical disk drive is operated from the initial sequence by a hardware reset signal from the host computer. For this reason, if the hardware reset signal is frequently asserted, the performance of the optical disk drive deteriorates, and the performance of the entire system is affected. Therefore, in order to assert the hardware reset signal, the host computer must know in advance when the optical disk drive enters the sleep mode. As described above, if the interface unit is stopped, it is difficult to adjust the timing at which the hardware reset signal (signal for returning the optical disk drive) is asserted. Therefore, the interface unit cannot be easily stopped. There was a problem.

  Further, the recovery operation performed after the optical disk drive enters the sleep mode is always led by the host computer. Therefore, depending on the operation of the host computer, the hardware reset signal may not be asserted, and thus there is a problem that it cannot be restored.

  In addition, with the advancement of the technology for increasing the data transfer rate, the technology is currently shifting from the ATA / ATAPI interface that is a parallel transfer method to the Serial ATA interface that is a serial transfer method. Compared to the ATA / ATAPI interface, the signal line of the SerialATA interface has been greatly reduced, and the signal line of the hardware reset signal from the host computer has also been deleted. It has become difficult to use.

  Furthermore, the Serial ATA interface requires an analog circuit that consumes a large amount of power in order to achieve high speed, and therefore the need to consider lower power consumption in the interface portion is greater than before. In the Serial ATA interface, each of the host computer and the external storage device can be shifted to a low power consumption mode called “Partial / Slumber”. However, even in “Slumber” which is the mode with the lowest power consumption, the Serial ATA interface is used. For this return sequence, some circuits must be operated, and it is difficult to stop them completely.

  In view of the above problems, an object of the present invention is to provide a power management technique that is effective for low power consumption operation of an information processing apparatus including an interface, particularly an information processing apparatus including a SerialATA interface. .

  According to the present invention, an information processing system is an information processing system including first and second information processing devices connected to each other via a cable, and each of the first and second information processing devices includes: An interface unit that is connected to one of both ends of the cable and that can be switched between a drive mode in which power is supplied and driven and a stop mode in which power supply is cut off and stopped; and operation of the interface unit A state notification unit for notifying the other information processing device of the state and a state detection for detecting the operation state of the interface unit in the other information processing device upon receiving a notification from the state notification unit included in the other information processing device Data transmission / reception between the information processing apparatus and the other information processing apparatus via the interface section of the information processing apparatus, and the state detection In accordance with the detection result of the operating conditions by including a CPU for controlling the operation status of the interface unit in the information processing apparatus.

  In each of the information processing systems, in each of the first and second information processing apparatuses, the CPU always changes the operation state of the other information processing apparatus (the operation state of the interface unit) without using the interface unit of the information processing apparatus. I can grasp it. Therefore, the interface unit can be stopped in each of the first and second information processing apparatuses. Thereby, the power consumption of the whole information processing system can be reduced.

  Preferably, in each of the first information processing apparatus and the second information processing apparatus, when the state detection unit detects that the operation state of the interface unit in the other information processing apparatus is in the stop mode, the CPU The interface unit in the information processing apparatus is set to the stop mode.

  In the information processing system, when one of the first and second information processing apparatuses is stopped at an arbitrary timing, the other information processing apparatus is also stopped in conjunction with the other information processing apparatus. Thereby, the power consumption of the whole information processing system can be reduced.

  Preferably, in each of the first and second information processing apparatuses, the interface unit further includes a low power consumption mode in which the amount of power supplied is smaller than that in the drive mode, and the CPU detects the state detection After detecting that the operation state of the interface unit in the other information processing apparatus is in the low power consumption mode by the unit, if the return to the drive mode is not detected within a predetermined period, the interface unit in the information processing apparatus is Enter stop mode.

  In the information processing system, since the first and second information processing apparatuses can be stopped, the power consumption of the entire information processing system can be further reduced.

  Preferably, at least one of the first and second information processing apparatuses further includes a communication state monitoring unit that monitors a connection state of the cable, and the CPU included in the information processing apparatus includes the communication state monitoring unit. The operation state of the interface unit in the information processing apparatus is controlled according to the result of monitoring by the unit.

  In the information processing system, the operation state of the interface unit can be controlled according to the connection state of the cable, and power consumption can be appropriately reduced.

  Preferably, in the information processing apparatus including the communication state monitoring unit, the CPU may return to the connected state within a predetermined period after the communication state monitoring unit detects that the cable is in a communication cut-off state. If not detected, the interface unit in the information processing apparatus is set to the stop mode.

  In the information processing system, power consumption by the interface unit can be prevented when the cable connection state is a communication cut-off state, and power consumption can be further reduced.

  Preferably, in each of the first and second information processing devices, the state notification unit notifies a return request instructing a return from the stop mode to the drive mode, and the CPU notifies the other by the state notification unit. When the return request from the state notification unit in the information processing apparatus is detected, the interface unit in the information processing apparatus is set to the drive mode.

  In the information processing system, in each of the first and second information processing apparatuses, the CPU can grasp the operation state of the connection destination apparatus even when the interface unit is stopped. A return request can be appropriately notified according to the state, and communication can be resumed between the first and second information processing apparatuses. In addition, the return operation can be started from either the first information processing apparatus or the second information processing apparatus.

  Further, according to the present invention, the control method of the information processing system includes a first and second interface unit having an interface unit capable of switching between a drive mode that is driven by being supplied with electric power and a stop mode that is stopped when electric power is cut off. Of the first information processing apparatus, and the interface units of the first and second information processing apparatuses are connected to each other via a cable, the first information A step (a) of causing the interface unit of the processing device to shift from the drive mode to the stop mode; and the second information processing that the interface unit of the first information processing device has entered the stop mode by the step (a). A step (b) of notifying the apparatus, and an interface of the second information processing apparatus in response to the notification of the step (b) The and a step (c) to shift to the stop mode from the drive mode.

  In the control method of the information processing system, the interface unit of the second information processing apparatus can be shifted to the stop mode in conjunction with the transition of the interface unit to the stop mode in the first information processing apparatus. Thereby, the power consumption of the whole information processing system can be reduced.

  Further, according to the present invention, the control method of the information processing system includes first and second interfaces having an interface unit capable of switching between a drive mode in which power is supplied and driven and a stop mode in which power supply is interrupted and stopped. A first information processing apparatus, and an interface section of each of the first information processing apparatus and the second information processing apparatus connected to each other via a cable. A step (a) of notifying a return request from the processing device to the second information processing device; and in response to the return request in step (a), the operation state of the interface unit of the second information processing device is stopped. Step (b) for returning from the mode to the drive mode, and the interface section of the second information processing device is set to the drive mode by the step (b). Step (c) for notifying the first information processing device of the return, and in response to the notification in step (c), returning the interface unit of the first information processing device from the stop mode to the drive mode. Step (d).

  In the control method of the information processing system, a return request can be appropriately notified even when the interface unit is stopped, and communication can be resumed between the first and second information processing apparatuses.

  As described above, according to the present invention, efficient control for reducing power consumption can be realized between the first and second information processing apparatuses connected via a cable.

  Hereinafter, embodiments for carrying out the present invention will be described with reference to the drawings.

(Embodiment 1)
<Configuration>
FIG. 1 shows the configuration of an information processing system according to Embodiment 1 of the present invention. In this information processing system, a host computer 1 and an external storage device 2 are connected to each other via an interface cable 100. The host computer 1 includes a host CPU 10, a device state detection unit 20, a host state notification unit 30, a host interface unit 40, an application (application) 200, a RAM 300, and a ROM 400. The external storage device 2 includes an optical disc control CPU 50, a device status notification unit 60, a host status detection unit 70, a device interface unit 80, a RAM 500, a ROM 600, and an optical disc control unit 700.

[Configuration of host computer]
The host CPU 10 controls various I / O devices (not shown), operates in response to command processing from the application 200, executes programs stored in the ROM 400, and the external storage device 2 via the host interface unit 40. Send / receive data. Further, the host CPU 10 receives the detection result of the device state detection unit 20 and controls the operation state of the host interface unit 40. Further, the host CPU 10 notifies the host state notification unit 30 of the operation state of the host interface unit 40. The application 200 accesses the RAM 300 and executes a program.

  The device state detection unit 20 receives the control signal from the device state notification unit 60 of the external storage device 2, detects the operation state of the device interface unit 80, and notifies the host CPU 10 of the detection result.

  The host status notification unit 30 receives a notification from the host CPU 10 and outputs a control signal indicating the operation status of the host interface unit 40 to the external storage device 2.

  In the figure, a signal line for transmitting a control signal from the device state notification unit 60 to the device state detection unit 20 and a signal line for transmitting a control signal from the host state notification unit 30 to the host state detection unit 70 are interfaces. Although described separately from the cable 100, it may be included in the interface cable 100.

  The host interface unit 40 is an interface that conforms to, for example, the Serial ATA standard, and is driven by being supplied with power, a low power consumption mode in which the amount of power supplied is lower than the drive mode, and power supply is cut off and stopped. And a complete stop mode.

[Configuration of external storage device]
The optical disc control CPU 50 interprets a command received via the device interface unit 80 and simultaneously writes data to or reads data from the optical disc 800 via the optical disc control unit 700. The optical disk control CPU 50 controls the operation state of the device interface unit 80 according to the detection result of the host state detection unit 70. Further, the optical disc control CPU 50 notifies the device state notification unit 60 of the operation state of the device interface unit 80.

  In response to the notification from the optical disc control CPU 50, the device state notification unit 60 outputs a control signal indicating the operation state of the device interface unit 80 to the host computer 1.

  The host state detection unit 70 receives a control signal from the host state notification unit 30 of the host computer 1 to detect the operation state of the host interface unit 40 and notifies the optical disc control CPU 50 of the detection result.

  The device interface unit 80 is, for example, an interface that conforms to the Serial ATA standard, and is driven by being supplied with power, a low power consumption mode in which the amount of power supplied is lower than the drive mode, and power supply is cut off and stopped. And a complete stop mode.

<Operation>
Next, the operation of the information processing system shown in FIG. 1 will be described. In this system, a process (device-host stop process) for setting the host interface unit 40 of the host computer 1 in a complete stop mode in response to the stop of the device interface unit 80 in the external storage device 2, and a host interface unit in the host computer 1 The process of setting the device interface unit 80 of the external storage device 2 to the complete stop mode in response to the stop of the host 40 (host-device stop process), and the operation state of the interface unit in each of the host computer 1 and the external storage device 2 are reduced. A process of shifting from the power consumption mode to the complete stop mode (complete stop process) and a process of returning the interface unit in each of the host computer 1 and the external storage device 2 from the complete stop mode to the drive mode (return process) are executed. .

<Device-host stop processing>
First, device-host stop processing will be described. As a condition for bringing the external storage device 2 into a complete stop state (that is, a condition for putting the device interface unit 80 into a complete stop mode), for example, a state where the optical disc control unit 700 cannot access the optical disc 800 or an optical disc connected to the external storage device 2 The case where 800 is not mounted can be considered. It should be noted that since the external storage device 2 is not limited to such a condition that it is completely stopped, it is apparent that the present invention is effective under other conditions.

  First, in the external storage device 2, the optical disc control CPU 50 outputs a stop request to the device interface unit 80. In response to the stop request from the optical disc control CPU 50, the device interface unit 80 shifts from the “drive mode” to the “complete stop mode”. Thereby, the device interface unit 80 completely stops the interface function.

  Next, after confirming that the device interface unit 80 is stopped, the optical disc control CPU 50 notifies the device state notification unit 60 of the operation state of the device interface unit 80. The device status notifying unit 60 sends a control signal indicating that the device interface unit 80 cannot access the host computer 1 (that is, the device interface unit 80 is in the “complete stop mode”) to the device status of the host computer 1. Output to the detector 20.

  Next, in the host computer 1, the device state detection unit 20 receives a control signal from the device state notification unit 60 of the external storage device 2, detects that the device interface unit 80 is in the “complete stop mode”, and The CPU 10 is notified.

  Upon receiving the notification from the device state detection unit 20, the host CPU 10 recognizes that the device interface unit 80 cannot be accessed (that is, the device interface unit 80 is in the “complete stop mode”), and the host CPU 10 Access to the interface unit 40 is stopped. Here, when stopping the host interface unit 40, the host CPU 10 makes a stop request to the host interface unit 40, and puts the host interface unit 40 into a complete stop mode. As a result, the host interface unit 40 completely stops the interface function.

  Next, after confirming that the host interface unit 40 is stopped, the host CPU 10 notifies the host state notification unit 30 of the operation state of the host interface unit 40. The host status notifying unit 30 sends a control signal indicating that the host interface unit 40 is stopped and inaccessible (that is, the host interface unit 40 is in the “complete stop mode”) to the host status of the external storage device 2. Output to the detector 70.

  When the device status detection unit 20 notifies that the device interface unit 80 is in the “complete stop mode”, the host CPU 10 does not stop the host interface unit 40 and responds to an access request from the application 200. The status indicating that the external storage device 2 cannot be accessed may be returned to the application 200.

  In this way, the host interface unit 40 can be stopped in response to the stop of the device interface unit 80, and the power consumption can be reduced. Specifically, power consumption can be reduced when preparations for data access are not completed in the external storage device 2 or when a medium such as the optical disc 800 is not inserted in the external storage device 2.

<Host-device stop processing>
Next, host-device stop processing will be described. As a condition for bringing the host computer 1 into the complete stop state (that is, a condition for putting the host interface unit 40 into the complete stop mode), for example, there is a case where it is not necessary to access the external storage device 2. This relates to the application 200 controlled by the host CPU 10. The application 200 includes a plurality of modules. Some applications operate by accessing the external storage device 2, and other applications operate without access. Therefore, setting the external storage device 2 to the complete stop state when the application 200 that accesses the external storage device 2 is not operating is effective in reducing power consumption.

  First, in the host computer 1, the host CPU 10 makes a stop request to the host interface unit 40. In response to the stop request from the host CPU 10, the host interface unit 40 enters the complete stop mode.

  Next, after confirming that the host interface unit 40 is stopped, the host CPU 10 notifies the host state notification unit 30 of the operation state of the host interface unit 40. The host status notification unit 30 sends a control signal indicating that the host interface unit 40 cannot access the external storage device 2 (that is, the host interface unit 40 is in the “complete stop mode”) to the external storage device 2. The data is output to the host state detection unit 70.

  Next, in the external storage device 2, the host state detection unit 70 receives a control signal from the host state notification unit 30 of the host computer 1, detects that the host interface unit 40 is in the “complete stop mode”, and the optical disk Notify the control CPU 50.

  Thereafter, similarly to the device-host stop process, the control of the optical disc control CPU 50 causes the device interface unit 80 to shift to the “complete stop mode” and a control signal indicating that the device interface unit 80 is in the “complete stop mode”. The data is output from the device status notification unit 60 to the device status detection unit 20 of the host computer 1.

  In this manner, the device interface unit 80 can be stopped in response to the stop of the host interface unit 40, and power consumption can be reduced.

<Complete stop processing>
Next, the complete stop process will be described. The Serial ATA standard includes a function for setting the interface to a low power consumption mode. However, since access is performed between the host computer 1 and the external storage device 2 even in the low power consumption mode, both the host computer 1 and the external storage device 2 cannot be completely stopped. Therefore, a technology for further reducing power consumption is required. In the Serial ATA standard, it is possible to shift to a low power consumption mode by communicating a specific pattern with each other via the interface cable 100.

  First, when the host computer 1 and the external storage device 2 are in the low power consumption state (that is, when the host interface unit 40 and the device interface unit 80 are in the “low power consumption mode”), in the host computer 1, the host CPU 10 The interface unit 40 notifies the host state detection unit 30 that it is in the “low power consumption mode”. On the other hand, in the external storage device 2, the host state detection unit 70 receives the control signal from the host state notification unit 30 and detects that the host interface unit 40 is in the “low power consumption mode”. After receiving the detection result, the optical disc control CPU 50 does not detect the return operation during a predetermined period (the host status detection unit 70 determines that the host interface unit 40 If it is not detected that the drive mode is set), a stop request is made to the device interface unit 80. The device interface unit 80 shifts to the complete stop mode in response to the stop request from the optical disc control CPU 50.

  Next, similarly to the device-host stop process, the operation state of the device interface unit 80 is notified from the optical disk control CPU 50 to the device state notification unit 60, and a control signal indicating that the device interface unit 80 is in the “complete stop mode”. Is notified from the device status notification unit 60 to the host computer 1.

  In this way, both the host interface unit 40 and the device interface unit 80 can be shifted from the low power consumption mode to the complete stop mode, and the power consumption can be further reduced.

  The host interface unit 40 may be stopped before the device interface unit 80. In this case, the host CPU 10, when the device state detection unit 20 detects that “the device interface unit 80 is in the low power consumption mode” and then does not detect a return operation within a predetermined period, A stop request is made to the interface unit 40. The subsequent processing is the same as the host-device stop processing.

<Return operation>
Next, the return process will be described with reference to FIG.

  First, in the host computer 1, the host CPU 10 confirms an access request from the application 200 to the external storage device 2 (ST101).

  Next, the host CPU 10 confirms the detection result of the host state detection unit 70 in order to confirm whether or not the external storage device 2 can be accessed (ST102).

  When the device interface unit 80 of the external storage device 2 can access the host computer 1 (that is, when the operation state of the device interface unit 80 is “drive mode”), the host CPU 10 changes the host interface unit 40 to “ The mode is shifted from the “complete stop mode” to the “drive mode”, and access to the device interface unit 80 is started via the host interface unit 40 in the drive mode (ST103).

  On the other hand, when the device interface unit 80 is in a state where the external storage device 2 cannot be accessed (that is, when the operation state of the device interface unit 80 is “complete stop mode”), the host CPU 10 requests the device interface unit 80 to return. Is notified to the host status notification unit 30. The host status notifying unit 30 outputs a control signal indicating the return request to the host status detecting unit 70 of the external storage device 2 (ST104).

  Next, in the external storage device 2, the host status detection unit 70 receives a control signal from the host status notification unit 30 of the host computer 1 and notifies the optical disk control CPU 50 of a return request from the host CPU 10. When the optical disc control CPU 50 confirms the return request, the optical disc control CPU 50 shifts the device interface unit 80 from the “complete stop mode” to the “drive mode” (ST105).

  On the other hand, in the host computer 1, the host CPU 10 receives the detection result from the device state detection unit 20, and confirms whether or not the operation state of the device interface unit 80 has returned to the “drive mode” (ST106).

  When the device interface unit 80 enters the “drive mode” and becomes accessible, the host CPU 10 shifts the host interface unit 40 from the “complete stop mode” to the “drive mode”, and the host interface unit 40 that has entered the drive mode. Then, access to the device interface unit 80 is started (ST107).

  In this manner, in each of the host computer 1 and the external storage device 2, the interface unit that is in the complete stop mode can be returned to the drive mode, and communication can be resumed.

  In the above description, the return operation is started from the host computer 1, but the return operation can also be started from the external storage device 2. In this case, the optical disk control CPU 50 detects the host state detection unit after returning the device interface unit 80 or notifying the device state notification unit 60 of the return request according to the detection result of the host state detection unit 70. What is necessary is just to comprise so that the device interface part 80 may be returned according to a result. Further, the host computer 1 may be configured such that the host CPU 10 returns the host interface unit 40 in response to the return request.

<Effect>
As described above, each of the host computer and the external storage device can always grasp the operation state of the interface unit in the information processing apparatus of the connection destination without using its own interface unit. Therefore, the interface unit can be stopped in each of the host computer and the external storage device. Thereby, the power consumption of the whole information processing system can be reduced.

  When one of the host computer and the external storage device shifts to the complete stop state, the other operation state also enters the complete stop state in conjunction with the shift. Thereby, the power consumption of the entire information processing system can be further reduced.

  Further, when the interface unit is capable of shifting to the low power consumption mode (for example, Serial ATA interface), the low power consumption mode can be shifted to the complete stop mode, and further reduction of power consumption can be realized. Is possible.

  Furthermore, each of the host computer and the external storage device can grasp the operation state of the connection destination device even if its own interface unit is stopped. Therefore, a return request is made according to the operation state of the connection destination device. Appropriate notifications can be made. In addition, the return operation can be started from either the host computer or the external storage device.

  Thus, efficient control for reducing power consumption can be realized between the host computer and the external storage device connected via the interface cable.

  Note that low power consumption can be realized even with only one of the host computer and the external storage device. In a system including both a host computer and an external storage device, more powerful and low power consumption can be realized.

  In the present embodiment, each of the host computer and the external storage device has been described as including a SerialATA interface. However, the present invention is not limited to this, and the same effect can be obtained with other equivalent interfaces. Is possible. Needless to say, the present invention is not limited to the host computer and the external storage device, and any information processing device including an interface unit can achieve the same effect.

(Embodiment 2)
<Configuration>
FIG. 3 shows a configuration of an information processing system according to the second embodiment of the present invention. In this information processing system, each of the host computer 1 and the external storage device 2 shifts to a complete stop state by detecting the connection state of the interface cable 100. The host computer 1 further includes a host communication state monitoring unit 90a in addition to the configuration shown in FIG. 1, and the external storage device 2 further includes a device communication state monitoring unit 90b in addition to the configuration shown in FIG. .

  The host communication state monitoring unit 90a monitors whether the interface cable 100 is electrically connected via the host interface unit 40, and notifies the host CPU 10 of the monitoring result. The device communication state monitoring unit 90b monitors whether the interface cable 100 is electrically connected via the device interface unit 80, and notifies the optical disc control CPU 50 of the monitoring result.

<Operation>
Next, the operation of the information processing system shown in FIG. 3 will be described. Here, a case where the external storage device 2 is shifted to the complete stop state according to the connection state of the interface cable 100 will be described.

  First, when the device communication state monitoring unit 90b detects that the connection state of the interface cable 100 is the communication cut-off state via the device interface unit 80, the device communication state monitoring unit 90b notifies the optical disk control CPU 50 of that fact. The optical disc control CPU 50 receives the notification from the device communication state monitoring unit 90b and recognizes that the interface cable 100 is in a communication cut-off state.

  Next, the optical disk control CPU 50 determines that “the interface cable 100 is in a connected state within a predetermined period after the device communication state monitoring unit 90b detects that the“ interface cable 100 is in a communication cutoff state ”. If it is not detected by the device communication state monitoring unit 90b, a stop request is made to the device interface unit 80. As a result, the device interface unit 80 enters the complete stop mode.

  Next, after confirming that the device interface unit 80 is in the complete stop mode, the optical disc control CPU 50 notifies the device state notification unit 60 that the device interface unit 80 is in the “complete stop mode”. The device status notification unit 60 outputs a control signal indicating that the device interface unit 80 is in the “complete stop mode” to the device status detection unit 20 of the host computer 1. Thereafter, the same processing as that in the first embodiment is executed.

  The host computer 1 performs similar processing. That is, the host communication state monitoring unit 90a monitors the connection state of the interface cable 100 via the host interface unit 40, and the host CPU 10 indicates that the interface cable 100 is in a communication cut-off state. If the host communication state monitoring unit 90a does not detect “the interface cable 100 has returned to the connected state” within a predetermined period after the detection by the host interface unit 40, the host interface unit 40 is set to the “complete stop mode”. To do.

<Effect>
As described above, in each of the host computer and the external storage device, the operation state of the interface unit can be controlled according to the connection state of the cable. Thereby, when the connection state of the cable is a communication cut-off state, waste of power by the interface unit can be prevented, and power consumption can be further reduced.

  In FIG. 3, the host computer 1 and the external storage device 2 each have a host communication state monitoring unit 90a and a device communication state monitoring unit 90b. However, if at least one of them is present, the waste of power is prevented. can do.

  In the information processing system according to the present invention, since the information processing apparatus can reduce power consumption in accordance with the operating state of the connection destination, the recording medium can be replaced with an optical disk device, a tape drive, a removable disk, a memory card, or the like. Application of is useful. Further, since power consumption can be reduced depending on whether or not a predetermined application can be accessed, it is also useful for application to a host computer or the like.

The block diagram which shows the structure of the information processing system by Embodiment 1 of this invention. The flowchart for demonstrating the return operation | movement by the information processing system shown in FIG. The block diagram which shows the structure of the information processing system by Embodiment 2 of this invention.

Explanation of symbols

100 cable 200 application 300 RAM (host computer)
400 ROM (host computer)
500 RAM (external storage device)
600 ROM (external storage device)
700 Optical disk control unit 800 Optical disk 10 Host CPU
20 Device status detection unit 30 Host status notification unit 40 Host interface unit 50 Optical disk control CPU
60 device state notification unit 70 host state notification unit 80 device interface unit 90a host communication state monitoring unit 90b device communication state monitoring unit

Claims (8)

An information processing system comprising first and second information processing devices connected to each other via a cable,
Each of the first and second information processing apparatuses
An interface unit that is connected to either one of both ends of the cable and that can be switched between a drive mode in which power is supplied and driven and a stop mode in which power feeding is interrupted and stopped;
A state notification unit for notifying the other information processing apparatus of the operation state of the interface unit;
A state detection unit that receives a notification from the state notification unit included in the other information processing apparatus and detects an operation state of the interface unit in the other information processing apparatus;
Data is transmitted to and received from the other information processing apparatus via the interface unit in the information processing apparatus, and the operation state of the interface unit in the information processing apparatus is determined according to the detection result of the operation state by the state detection unit. An information processing system including a controlling CPU. In claim 1,
In each of the first and second information processing apparatuses,
The CPU sets the interface unit in the information processing apparatus to the stop mode when the state detection unit detects that the operation state of the interface unit in the other information processing apparatus is in the stop mode. Processing system. In claim 1,
In each of the first and second information processing apparatuses,
The interface unit further includes a low power consumption mode in which less power is supplied than in the drive mode,
When the state detection unit detects that the operation state of the interface unit in the other information processing apparatus is in the low power consumption mode by the state detection unit, the CPU does not detect the return to the drive mode within a predetermined period. An information processing system in which an interface unit in an information processing apparatus is set to a stop mode. In claim 1,
At least one of the first and second information processing devices is
A communication state monitoring unit for monitoring the connection state of the cable;
The CPU included in the information processing apparatus further controls an operation state of an interface unit in the information processing apparatus according to a result of monitoring by the communication state monitoring unit. In claim 4,
In the information processing apparatus including the communication state monitoring unit,
The CPU, when the communication state monitoring unit detects that the cable is in a communication cut-off state, and when the return to the connection state is not detected within a predetermined time, the CPU in the information processing apparatus is stopped An information processing system characterized by that. In claim 1,
In each of the first and second information processing apparatuses,
The state notification unit notifies a return request instructing a return from the stop mode to the drive mode,
When the status notification unit detects a return request from the state notification unit in the other information processing apparatus, the CPU sets the interface unit in the information processing apparatus to a drive mode. A first and a second information processing device having an interface unit capable of switching between a drive mode driven by power supply and a stop mode stopped when power supply is cut off, and the first and second information processing devices; A method for controlling an information processing system in which each interface unit of an information processing device is connected to each other via a cable,
A step (a) of causing the interface unit of the first information processing apparatus to shift from the drive mode to the stop mode;
(B) notifying the second information processing apparatus that the interface unit of the first information processing apparatus is in the stop mode by the step (a);
A control method for an information processing system comprising: (c) a step of shifting an interface unit of the second information processing apparatus from a drive mode to a stop mode in response to the notification in the step (b). 1st and 2nd information processor which has an interface part which can be switched between the driving mode which drives by supplying electric power, and the stop mode which cuts off electric power supply, and stops, and said 1st and 2nd A method for controlling an information processing system in which each interface unit of an information processing device is connected to each other via a cable,
A step (a) of notifying a return request from the first information processing apparatus to the second information processing apparatus;
In response to the return request in step (a), the step (b) of returning the operation state of the interface unit of the second information processing apparatus from the stop mode to the drive mode;
(C) notifying the first information processing apparatus that the interface unit of the second information processing apparatus has returned to the drive mode by the step (b);
A control method for an information processing system, comprising: a step (d) of returning the interface unit of the first information processing apparatus from a stop mode to a drive mode in response to the notification in the step (c).

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