JP5304210B2 - Control system - Google Patents

Description

  The present invention relates to a control system capable of reliably and easily performing control of a controlled device by a control device, particularly control related to switching of an operation state of the controlled device.

  FIG. 4 is a block diagram showing a configuration of a conventional control system. The illustrated control system includes an MCU (Micro Controller Unit) 101 as a control device and an ASIC (Application Specific Integrated Circuit) 102 as a controlled device. The MCU 101 is a device that is provided in a device such as an ECU (Electronic Control Unit) mounted on a vehicle and performs arithmetic processing, control processing, and the like, and controls the operation of the ASIC 102 and other devices. The MCU 101 has a Tx terminal for transmitting data by serial communication and an Rx terminal for receiving data.

  Similarly, the ASIC 102 has a Tx terminal for transmitting data by serial communication and an Rx terminal for receiving data. The Tx terminal of the MCU 101 and the Rx terminal of the ASIC 102 are connected via a signal line, and the Rx terminal of the MCU 101 and the Rx terminal of the ASIC 102 are connected by a signal line, and data transmission from the MCU 101 to the ASIC 102 and from the ASIC 102 to the MCU 101 is performed. Can do.

  The ASIC 102 is a device that operates according to control information transmitted from the MCU 101 by serial communication. Further, the ASIC 102 receives an input signal from another device and transmits information obtained thereby to the MCU 101 by serial communication. The ASIC 102 is an apparatus that receives input signals from various sensors or operation switches as another apparatus, for example, and transmits information regarding the state of the sensors or operation switches obtained based on the received input signals to the MCU 101.

  In a control system configured to transmit and receive data via serial communication between the control device and the controlled device in this way, data transmission and reception should be performed correctly when a communication failure occurs due to electrical noise superimposed on the signal line. The control device or the controlled device may operate abnormally.

Patent Document 1 proposes an input / output unit capable of reliably transferring data between internal devices without being subjected to abnormal processing even under an environment affected by electrical noise. This input / output unit has a configuration in which an MCU (Micro Controller Unit) and an ASIC (Application Specific Integrated Circuit) perform serial communication. When receiving a NAK signal when transmitting data to each other, a heartbeat command Send. The heartbeat command is a signal that is sent to notify the outside that the device is operating normally. The data length is shorter than the data that is sent and received by normal communication, so the influence of electrical noise is reduced. You can send it to the other party without receiving it. Therefore, it is possible to receive the ACK signal from the transmission partner and clear its own watchdog timer, so that the input / output unit can be prevented from being stopped due to the influence of electrical noise.
JP 2002-202920 A

  However, the input / output unit described in Patent Document 1 is configured to transmit a heartbeat command to avoid communication failure when data transmission / reception via serial communication fails, but the heartbeat command is more effective than normal transmission / reception data. Even if the data length is short, there is no guarantee that it will not be affected by electrical noise at all. Therefore, if transmission / reception of the heartbeat command cannot be performed normally due to electrical noise, the input / output unit may stop due to abnormal operation of the MCU or ASIC.

  In particular, when the control system is mounted on a device that operates with a battery such as an in-vehicle device or a portable device, it is desired to stop the operation of the device as much as possible in order to reduce power consumption. Therefore, in the conventional control system, the MCU 101 has a low power operation state (hereinafter referred to as a sleep mode) in which processing is stopped and power consumption is reduced, and a high power operation state (hereinafter referred to as normal mode) in which processing is performed and power consumption is large. It is desirable to be able to switch between modes). In this case, when the MCU 101 is in the sleep mode, the ASIC 102 does not receive a control signal from the MCU 101 and needs to operate independently. Therefore, the ASIC 102 has a function of switching between a subordinate operation state (hereinafter referred to as a subordinate mode) that operates according to the control of the MCU 101 and an independent operation state (hereinafter referred to as an independent mode) that operates independently from the control of the MCU 101. Can be considered.

  In the conventional control system, the switching of the dependent mode or the independent mode of the ASIC 102 can be configured to be controlled by the MCU 101 by serial communication. However, when a failure occurs in the serial communication due to the influence of electrical noise as described above, for example, the MCU 101 shifts to the sleep mode despite the failure of the ASIC 102 to switch to the independent mode, and the MCU 101 and the ASIC 102 There is a possibility that the control system may be in an unrecoverable operating state, for example, both of these operations stop.

  The present invention has been made in view of such circumstances, and the object of the present invention is to control the operation mode of the device when the control device and the controlled device perform processing by communicating with each other. An object of the present invention is to provide a control system capable of reliably performing important communication such as change.

A control system according to the present invention includes a control device and a controlled device whose operation is controlled by the control device, and the control device and the controlled device each have a communication unit that exchanges information by serial communication. The control device operates in a high power operation state with high power consumption or a low power operation state with low power consumption, and in the high power operation state, the control device transmits control information by the communication means. A control system in which the controlled device operates in a dependent operation state in which the controlled device operates in accordance with the control of the control device or in an independent operation state in which the controlled device operates independently of the control device. disposed between the control device, wherein the switching signal line for transmitting and receiving a switching signal for switching the dependent operating state or an independent operating state of the controlled device, the control device and Disposed between the control device, wherein a interrupt signal line for transmitting and receiving an interrupt signal to the controller from the controlled device, the control device interrupts from serial communication and other devices by the communication unit Prohibiting means for prohibiting acceptance of a signal, and switching that associates switching of a binary signal level with switching of a dependent operation state or an independent operation state of the controlled device after the prohibiting means prohibits acceptance of an interrupt signal. A signal is transmitted to the controlled device via the switching signal line, and the switching unit switches the controlled device from a dependent operation state to an independent operation state by the switching signal, and after the switching unit performs switching, Permission means for permitting acceptance of an interrupt signal from the controlled device, and after the permission means permits acceptance of the interrupt signal, the high power operation Transition from the low power operating state to the high power operating state in response to an interrupt signal given from the controlled device via the interrupt signal line. It is characterized by being.

  In the control system according to the present invention, the controlled device has detection means for detecting a change in an input signal from another device, and interrupts the control device when the detection means detects the change. It is characterized by transmitting a signal.

In the present invention, a switching signal for switching the dependent mode (dependent operation state) or independent mode (independent operation state) of the controlled device is transmitted from the control device to the controlled device between the control device and the controlled device. A signal line is provided. The control device sends a digital switching signal that associates switching of the dependent mode or independent mode of the controlled device to switching of the binary signal level (high potential / low level of the potential) via a dedicated signal line. By transmitting to the controlled device, the operation mode of the controlled device is controlled.
Controlled to high level / low level using a dedicated signal line provided between the control device and the controlled device without using serial communication that allows data transmission / reception between the control device and the controlled device Since the switching signal is associated with the operation mode of the device, even if the electrical noise is superimposed on the signal line for a certain period, the influence of the electrical noise is reduced after a certain period. After that, the controlled device can correctly recognize the high level / low level of the switching signal. Therefore, the controlled device can reliably switch the operation mode according to the switching signal.

  In the present invention, a signal line for transmitting an interrupt signal from the controlled device to the control device is further provided between the control device and the controlled device. Since the control device stops arithmetic processing, control processing, and the like in the sleep mode (low power operation state), the controlled device operates in the independent mode. When the controlled device operating in the independent mode determines that the processing by the control device is necessary, the controlled device moves the control device from the sleep mode to the normal mode (high power operation state) to start the processing of the control device. ) Must be transferred to. In view of this, a configuration is adopted in which the controlled device shifts to the normal mode when the controlled device transmits an interrupt signal to the control device using a dedicated signal line provided between the controlled device and the controlled device. Thus, even when the control device cannot perform serial communication in the sleep mode, communication from the controlled device to the control device can be performed via the signal line.

In the present invention, when the control device shifts from the normal mode to the sleep mode, the shift is performed after the processing of the following procedure is performed. First, the control device prohibits serial communication with the controlled device and acceptance of interrupt signals from other devices including the controlled device. Thus, important processing for shifting the operation mode is not hindered by serial communication or interruption from another device.
Next, the control device shifts the controlled device from the dependent mode to the independent mode by outputting a switching signal via the signal line. At this time, the control device may perform processing for shifting to its own operation mode such as saving data stored in a register or the like or changing the number of operation clocks.
Thereafter, the control device permits acceptance of an interrupt signal from the controlled device (may accept acceptance of interrupt signals from other devices), and shifts from the normal mode to the sleep mode. With these procedures, the control device can reliably shift the controlled device to the subordinate mode, and thereafter can surely shift to the sleep mode.

  In the present invention, when the controlled device is in the independent mode, the controlled device accepts an input signal from another device such as an operation switch or a sensor, and the controlled device detects a change in the input signal. When an input signal from another device changes and is detected, the controlled device notifies the control device of the change in the input signal by an interrupt signal via the signal line. As a result, the controlled device can determine whether or not processing by the control device is necessary depending on whether or not the input signal has changed. If it is determined that processing is necessary, the controlled device can interrupt the control device. The process can be started by shifting to the normal mode.

  In the case of the present invention, a signal line for transmitting and receiving a switching signal for switching the dependent mode or the independent mode of the controlled device is provided between the control device and the controlled device to switch the signal level between the high level and the low level. Serial communication that is easily affected by electrical noise by configuring the control device to transmit a switching signal that associates switching between the dependent mode or independent mode of the controlled device to the controlled device via a signal line The control device can switch the mode of the controlled device without using. The controlled device can accept the control of the operation mode switching by the control device only by determining the potential of the signal line, and the switching signal that can switch the mode by the high level or low level switching is an electric noise. Therefore, the operation mode of the controlled device can be reliably switched by the control device, and the reliability of the operation of the control system can be improved.

  Hereinafter, the present invention will be specifically described with reference to the drawings showing embodiments thereof. FIG. 1 is a block diagram showing a configuration of a control system according to the present invention. The control system according to the embodiment includes an MCU 1 as a control device and an ASIC 2 as a controlled device. The MCU 1 is a device (or IC (Integrated Circuit)) that is mounted on an electronic device and performs various arithmetic processing and control processing, and the operation of the ASIC 2 and other devices (not shown) mounted on the electronic device. Is controlling.

  The ASIC 2 is a device that acquires (samples) an input signal from another device such as a sensor or an operation switch according to the control of the MCU 1 and transmits information related to the acquired input signal to the MCU 1 by serial communication. For this reason, the MCU 1 and the ASIC 2 are connected via a serial signal line 5 for performing serial communication. In the control system according to the present invention, two signal lines 6 and 7 for connecting the MCU 1 and the ASIC 2 are provided.

  The MCU 1 includes a control unit 11, a serial communication unit 12, an interrupt signal reception unit 15, a switching signal transmission unit 16, and the like. In the MCU 1 shown in FIG. 1, only functional blocks related to control processing and communication processing for the ASIC 2 are shown, and other functional blocks are not shown.

  The serial communication unit 12 converts the parallel data supplied from the control unit 11 into serial data and transmits it to the ASIC 2, and receives the serial data transmitted from the ASIC 2, converts the parallel data into parallel data, and converts the parallel data into the control unit. 11 is provided with a receiving unit 13 that supplies the signal to 11. The reception unit 13 and the transmission unit 14 are connected to the ASIC 2 via the signal line 5 for serial communication, and the serial communication unit 12 can perform bidirectional serial communication with the ASIC 2. Note that the serial communication signal line 5 may be configured to share one signal line for transmission and reception, or may be configured to use two different signal lines for transmission and reception, respectively.

  The interrupt signal receiving unit 15 is connected to the ASIC 2 via the signal line 6 and notifies the control unit 11 when an interrupt signal from the ASIC 2 is received. For example, a high-level pulse signal for a certain period can be used as the interrupt signal, and the interrupt signal receiving unit 15 detects an interrupt from the ASIC 2 by detecting a high level of the pulse signal or a rising / falling edge. Can be accepted.

  The switching signal transmission unit 16 is connected to the ASIC 2 via the signal line 7 and switches the operation mode (details will be described later) of the ASIC 2 in the dependent mode (dependent operation state) or the independent mode (independent operation state). A switching signal is transmitted to ASIC2. The switching signal is a binary signal having a high level or a low level. For example, the high level is associated with the subordinate mode of ASIC2, and the low level is associated with the independent mode of ASIC2. When the switching signal transmitter 16 switches the high level / low level of the switching signal, the MCU 1 can switch the operation mode of the ASIC 2 to the subordinate mode or the independent mode.

  The control unit 11 performs various arithmetic processes and performs a control process for controlling the operation of each part of the MCU 1. The control unit 11 can control the operation of the ASIC 2 by transmitting an operation command, data necessary for this operation, and the like to the ASIC 2 by serial communication via the serial communication unit 12. A serial signal obtained by sampling an input signal from another device and performing parallel / serial conversion is supplied from the ASIC 2 by serial communication, and the control unit 11 performs arithmetic processing and control processing according to the value of the input signal. I do.

  In addition, the control unit 11 performs these arithmetic processing, control processing, and the like, and stops the operation of each unit without performing the normal mode (high power operation state) for controlling the operation of each unit and the ASIC 2 and the like. Thus, the operation mode of the MCU 1 can be switched to a sleep mode (low power operation state) in which power consumption is reduced. When the MCU 1 is in the sleep mode, the control unit 11 does not perform arithmetic processing and control processing, and the serial communication unit 12 does not perform serial communication with the ASIC 2. Thereby, the power consumption of MCU1 is reduced and the power consumption of the whole control system is reduced.

  However, even in the case of the sleep mode, the interrupt signal receiving unit 15 receives the interrupt signal from the ASIC 2, and the interrupt signal receiving unit 15 notifies the control unit 11 by receiving the interrupt signal. The control unit 11 returns the MCU 1 from the sleep mode to the normal mode. Further, when the MCU 1 is in the sleep mode, the switching signal transmission unit 16 causes the ASIC 2 to operate in the independent mode by continuing to output the low level switching signal.

  The ASIC 2 includes a control unit 21, a serial communication unit 22, an interrupt signal transmission unit 25, a switching signal reception unit 26, an I / F (interface) unit 27, and the like. Similarly to the serial communication unit 12 of the MCU 1, the serial communication unit 22 receives the serial data transmitted from the MCU 1 and the transmission unit 23 that converts the parallel data supplied from the control unit 21 into serial data and transmits the serial data to the MCU 1. And a receiving unit 24 that converts the parallel data into the control unit 21. The transmission unit 23 and the reception unit 24 are connected to the MCU 1 via the signal line 5, and the serial communication unit 22 can perform bidirectional serial communication with the serial communication unit 12 of the MCU 1.

  The interrupt signal transmission unit 25 is connected to the interrupt signal reception unit 15 of the MCU 1 through the signal line 6, and, for example, a high-level pulse signal for a certain period is used as an interrupt signal according to the control of the control unit 21. It transmits to the interrupt signal receiver 15 of MCU1. As a result, the ASIC 2 can shift the MUC 1 from the sleep mode to the normal mode. The switching signal receiving unit 26 is connected to the switching signal transmitting unit 16 of the MCU 1 via the signal line 7, and determines whether the signal level of the switching signal transmitted from the MCU 1 is high level or low level. The determination result is notified to the control unit 21.

  The I / F unit 27 samples an input signal from another device such as a sensor or an operation switch under the control of the control unit 21, and gives the value of the sampled input signal to the control unit 21. The sampling period of the input signal by the I / F unit 27 is controlled by the control unit 21. In FIG. 1, the I / F unit 27 of the ASIC 2 is configured to only accept input signals from other devices, but is not limited thereto, and is configured to output signals such as control information to other devices. It is good.

  The control unit 21 performs various arithmetic processes, control processes for each part of the ASIC 2, and the like. The control unit 21 can switch the operation mode of the ASIC 2 between a subordinate mode that operates according to the control of the MCU 1 and an independent mode that operates independently when the MCU 1 does not operate in the sleep mode. The control unit 21 switches between the dependent mode and the independent mode according to the signal level of the switching signal from the MCU 1 received by the switching signal receiving unit 26. For example, the control unit 21 sets the ASIC 2 to the subordinate mode when the switching signal is at the high level, and sets the ASIC 2 to the independent mode when the switching signal is at the low level.

  When the ASIC 2 is in the subordinate mode, the control unit 21 receives an operation command, data, and the like given from the MCU 1 by the serial communication unit 22 and operates each unit according to the received content. For example, when the ASIC 2 is in the subordinate mode, the control unit 21 receives a sampling period setting of the input signal from the MCU 1 by serial communication, performs sampling with the received period setting, and transmits the value of the input signal to the MCU 1. The MCU 1 that has received the value of the input signal by serial communication can perform an operation according to this value.

  When the ASIC 2 is in the independent mode, the control unit 21 controls the operation of each unit in accordance with a predetermined operation setting (or set by the MCU 1 in the subordinate mode) to operate the ASIC 2. For example, when the ASIC 2 is in the independent mode, the control unit 21 samples the input signal with a predetermined cycle setting.

  Further, when the ASIC 2 is in the independent mode, the control unit 21 detects a change in the input signal by comparing the input signal sampled by the I / F unit 27 with the input signal sampled immediately before. When the input signal changes, the control unit 21 controls the interrupt signal transmission unit 25 to give an interrupt signal to the MCU 1 to notify that the input signal has changed. As a result, the MCU 1 returns from the sleep mode to the normal mode, acquires the value of the input signal sampled from the ASIC 2 by serial communication, and can perform an operation corresponding thereto.

  When MCU 1 is in the normal mode and ASIC 2 is in the subordinate mode, the ASIC 2 transmits the value of the sampled input signal to the MCU 1 by serial communication regardless of whether or not the input signal has changed, and the control unit of the MCU 1 11 can detect a change in the input signal.

  FIG. 2 is a flowchart showing a procedure of processing performed by the MCU 1 of the control system according to the present invention, and is processing performed by the control unit 11 of the MCU 1. For example, after the power of the MCU 1 is turned on, the control unit 11 first sets the operation mode of the MCU 1 to the normal mode (step S1). Next, the control unit 11 performs serial communication with the ASIC 2 by the serial communication unit 12 (step S2), and acquires the value of the input signal sampled by the ASIC 2. At this time, the control unit 11 may transmit an operation command, data, and the like to the ASIC 2 by serial communication, such as transmitting a sampling cycle setting to the ASIC 2. Then, the control part 11 performs various processes, such as a calculation process and a control process according to the value of the acquired input signal (step S3).

  The control unit 11 performs processing according to the input signal. However, for example, when the value of the input signal does not change over a long period of time, it is not necessary to perform arithmetic processing and control processing, so the normal mode is changed to the sleep mode. Shift to reduce power consumption. Therefore, after performing the process according to the input signal, the control unit 11 determines whether or not to change the operation mode from the normal mode to the sleep mode, for example, by determining whether or not the input signal has changed during a certain period. Is determined (step S4). For example, when the input signal has changed and it is determined that the process needs to be continued and it is determined not to change the operation mode (S4: NO), the control unit 11 returns to step S1 and performs the above-described process. Repeat.

  For example, if the input signal has not changed for a certain period and it is determined that the operation mode is to be changed (S4: YES), the controller 11 first prohibits all interrupts from the ASIC 2 and other devices not shown (step) S5). Next, the control unit 11 switches the operation signal of the ASIC 2 from the dependent mode to the independent mode by switching the switching signal from the high level to the low level at the switching signal transmission unit 16 (step S6). Next, the control unit 11 performs processing necessary for the MCU 1 to enter the sleep mode, for example, preparation processing such as saving data stored in the register or changing the clock frequency (step S7), and the interrupt signal receiving unit 15 Is permitted to accept an interrupt from the ASIC 2 (step S8). At this time, acceptance of an interrupt from a device other than the ASIC 2 may be permitted.

  Thereafter, the control unit 11 sets the operation mode of the MCU 1 to the sleep mode (step S9), and determines whether or not an interrupt is given from the ASIC 2 by receiving an interrupt signal at the interrupt signal receiving unit 15 (step S9). S10). If no interrupt is given (S10: NO), the control unit 11 returns to step S9 and maintains the sleep mode. When an interrupt is given (S10: YES), the control unit 11 switches the operation mode of the ASIC 2 from the independent mode to the subordinate mode by switching the switching signal from the low level to the high level in the switching signal transmission unit 16. (Step S11), the process returns to Step S1, shifts from the sleep mode to the normal mode, and the above-described processing is repeated.

  FIG. 3 is a flowchart showing a procedure of processing performed by the ASIC 2 of the control system according to the present invention, which is processing performed by the control unit 21 of the ASIC 2. After the power of the ASIC 2 is turned on, the control unit 21 first checks the signal level of the switching signal transmitted from the MCU 1 with the switching signal receiving unit 26 and determines whether or not the switching signal is at a high level. (Step S21). When it is determined that the switching signal is at the high level (S21: YES), the control unit 21 sets the ASIC 2 to the subordinate mode (step S22), and the serial communication unit 22 receives an operation command from the MCU 1 and data related thereto. Then, processing according to the control of the MCU 1 is performed (step S23), and the process returns to step S21.

  When it is determined that the switching signal is at a low level (S21: NO), the control unit 21 sets the ASIC 2 to the independent mode (step S24), and samples the input signal at a predetermined cycle by the I / F unit 27. This is performed (step S25). Next, the control unit 21 determines whether or not the input signal has changed by comparing the sampled input signal with the input signal sampled immediately before (step S26). When it determines with the input signal not changing (S26: NO), the control part 21 returns to step S21, and performs the above-mentioned process repeatedly. When it is determined that the input signal has changed (S26: YES), the control unit 21 interrupts the MCU1 by transmitting an interrupt signal from the interrupt signal transmission unit 25 (step S27), and sleeps the MCU1. The mode is returned to the normal mode, the process returns to step S21, and the above process is repeated.

  In the control system having the above configuration, when the MCU 1 is operating in the normal mode, the MCU 1 performs serial communication between the MCU 1 and the ASIC 2, and the MCU 1 transmits settings such as a sampling period and an operation command to the ASIC 2. By transmitting the sampled input signal to the MCU 1, the MCU 1 can perform an operation according to the input signal from another device such as a sensor or an operation switch. At this time, the ASIC 2 operates in the subordinate mode, samples the input signal in accordance with an operation command or the like given from the MCU 1 through serial communication, and transmits the sampled input signal to the MCU 1 as serial data.

  When the MCU 1 does not need to operate, for example, when the input signal does not change over a long period of time, the MCU 1 shifts from the normal mode to the sleep mode to stop the operation and reduce power consumption. In the sleep mode, serial communication with the ASIC 2 is not performed. When the MCU 1 shifts from the normal mode to the sleep mode, first, all external interrupts are prohibited, and the operation mode of the ASIC 2 is changed from the dependent mode to the independent mode by switching the switching signal to the ASIC 2 from the high level to the low level. After performing preparatory processing such as saving the data in the register, the interrupt from the ASIC 2 is permitted, and the mode shifts to the sleep mode. By switching the ASIC2 operation mode after prohibiting external interrupts, there is no possibility that the critical mode switching process will be interrupted by an interrupt from another device, and the MCU1 will change the ASIC2 from the subordinate mode. Can be switched to reliably.

  When the switching signal from the MCU 1 is switched from the high level to the low level, the ASIC 2 switches the operation mode from the dependent mode to the independent mode. At this time, even if noise is superimposed on the switching signal to the ASIC 2 and the switching of the operation mode of the ASIC 2 is not performed correctly, the signal line 7 that is a dedicated line provided between the MCU 1 and the ASIC 2 is connected. Since the switching signal transmitted / received via the high-level signal level or the low-level signal level is associated with the subordinate mode or the independent mode of the ASIC 2, it is ensured that the influence of noise decreases after a certain period of time has elapsed. The operation mode of the ASIC 2 is switched.

  When operating in the independent mode, the ASIC 2 cannot perform serial communication with the MCU 1, so it repeatedly samples the input signal at a predetermined frequency and compares the latest sampling result with the immediately preceding sampling result. To detect changes in the input signal. When the input signal changes, the ASIC 2 interrupts the MCU 1 to return from the sleep mode to the normal mode, whereby the serial communication of the MCU 1 and the ASIC 2 is resumed, and the MCU 1 acquires the changed input signal and responds accordingly. Can be processed.

  In this embodiment, the ASIC 2 that performs sampling of the input signal is described as an example of the controlled device of the control system. However, the controlled device is not limited to this and is a device that performs other processing. The configuration of the present invention can be applied to any control system in which the control device and the controlled device exchange information related to control through serial communication.

It is a block diagram which shows the structure of the control system which concerns on this invention. It is a flowchart which shows the procedure of the process which MCU of the control system which concerns on this invention performs. It is a flowchart which shows the procedure of the process which ASIC of the control system which concerns on this invention performs. It is a block diagram which shows the structure of the conventional control system.

Explanation of symbols

1 MCU (control unit)
2 ASIC (controlled device)
5 Signal line 6 Signal line 7 Signal line 11 Control unit (prohibiting means, switching means, permitting means)
12 Serial communication part (communication means)
15 Interrupt signal receiving unit 16 Switching signal transmitting unit 21 Control unit (detection means)
22 Serial communication part (communication means)
25 Interrupt signal transmitter 26 Switching signal receiver 27 I / F unit

Claims (2)

A control device and a controlled device whose operation is controlled by the control device;
The control device and the controlled device each have communication means for transferring information by serial communication,
The control device operates in a high power operation state with high power consumption or a low power operation state with low power consumption, and in the high power operation state, the control device transmits control information by the communication means. Control the operation of
The controlled device is a control system that operates in a dependent operation state that operates according to the control of the control device or an independent operation state that operates independently of the control device,
A switching signal line arranged between the control device and the controlled device, for transmitting and receiving a switching signal for switching the dependent operation state or the independent operation state of the controlled device ;
An interrupt signal line arranged between the control device and the controlled device, for transmitting and receiving an interrupt signal from the controlled device to the control device ;
The controller is
Prohibiting means for prohibiting serial communication by the communication means and acceptance of interrupt signals from other devices;
After the prohibiting means prohibits acceptance of the interrupt signal, a switching signal in which switching of the binary signal level is associated with switching of the dependent operation state or the independent operation state of the controlled device is transmitted via the switching signal line. Switching means for transmitting to the controlled device and switching the controlled device from a dependent operation state to an independent operation state by the switching signal;
Permission means for allowing acceptance of an interrupt signal from the controlled device after the switching means performs switching;
Have
After the permission means permits the acceptance of the interrupt signal, the high power operation state is shifted to the low power operation state, and according to the interrupt signal given from the controlled device via the interrupt signal line, The control system is configured to shift from the low power operation state to the high power operation state . The controlled device is:
Having detection means for detecting a change in an input signal from another device;
Control system according to claim 1, characterized in that the detecting means when detecting a change, are to be transmitted an interrupt signal to the control device.

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