JP2017220831A - Communication apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a communication apparatus that is able to prevent, in a case where only one transceiver is provided for a plurality of controllers, the controllers from being erroneously waken up by a noise signal from the transceiver.SOLUTION: Among a plurality of controllers, at least a controller that enters a sleep mode first is provided with a wakeup inhibition storage section 14. On the basis of a standby signal of the other controllers, the wakeup inhibition storage section 14 determines that a transceiver is switched to a standby mode. For a predetermined time from the switching of the transceiver to the standby mode, the wakeup inhibition storage section holds the wakeup inhibition information that is information for inhibiting a wakeup process corresponding to an input signal, which is performed by a wakeup control section 13. While the wakeup inhibition information is held, the wakeup control section 13 does not allow a control section 11 to wake up even when a signal input from a signal input terminal Rx1 changes.SELECTED DRAWING: Figure 2

Description

  The present invention relates to a communication apparatus provided with only one transceiver for transmitting and receiving signals on a communication bus to a plurality of controllers.

  For example, Patent Document 1 discloses an apparatus in which only one transceiver that realizes transmission and reception of signals through a bus line is provided for a plurality of controllers. In the apparatus disclosed in Patent Document 1, the transceiver is provided with a standby terminal in addition to the transmission terminal and the reception terminal. When a standby signal of a predetermined level is input to the standby terminal, the transceiver enters a standby mode (low power consumption mode), and the function of transmitting a signal to the bus line is stopped.

  Here, when two controllers as a plurality of controllers share one transceiver, one of the controllers has a low level from both the signal output terminal and the standby output terminal due to a failure or power-off state. It is conceivable to output a signal. In this case, the signal sent to the bus line by the transceiver is fixed at the dominant level by the low level signal output from the signal output terminal of one controller, and communication between all communication devices connected on the bus line is performed. May be disturbed.

  For this reason, in the apparatus of Patent Document 1, when a low level signal is output from both the signal output terminal and the standby output terminal of the controller, the low level signal output from the signal output terminal is input to the transmission terminal of the transceiver. In order to prevent this, an adjustment circuit for adjusting the signal level is provided.

JP 2007-245891 A

  As described above, when the transceiver has a standby terminal, for example, when a plurality of controllers finish executing necessary functions and enter a sleep mode, the transceiver can be shifted to a standby mode. As a whole, it is possible to reduce power consumption.

  However, when the standby signal is input to the standby terminal and the transceiver is switched from the normal mode to the standby mode, the transceiver may have an indefinite signal level at the receiving terminal and output a noise signal from the receiving terminal to the controller.

  In a configuration in which a plurality of controllers share one transceiver, each controller may enter a sleep mode and output a standby signal at different times. In this case, the transceiver shifts to the standby mode when the standby signal is output from the controller that finally enters the sleep mode. In this way, the controller that finally enters the sleep mode can grasp the timing of switching to the standby mode because the transceiver is switched to the standby mode by the standby signal output by itself. Therefore, for example, if the signal output from the receiving terminal of the transceiver is ignored when switching to the standby mode, the noise signal is mistakenly recognized as a signal from another communication device and erroneously woken up. Can be prevented.

  However, the controller that is in sleep mode first cannot know when the transceiver switches to standby mode. For this reason, there is a possibility that the noise signal output from the reception terminal of the transceiver may wake up accidentally. The controller that wakes up by mistake may transmit a signal to the communication bus and wake up another controller.

  The present invention has been made in view of the above points, and prevents a controller from being woken up erroneously by a noise signal from a transceiver when only one transceiver is provided for a plurality of controllers. An object of the present invention is to provide a communication device capable of performing the above.

In order to achieve the above object, a communication device (100) according to the present invention communicates with another communication device via a communication bus,
A plurality of controllers (10, 20) for generating and outputting a signal to be transmitted and processing an input signal, and outputting a standby signal in the sleep mode;
When signals output from multiple controllers are sent to the communication bus, and signals sent from other communication devices to the communication bus are received and input to multiple controllers when a standby signal is input A transceiver (50) for switching from a normal operation mode to a standby mode to stop transmission operation;
A coupling unit (40) that is interposed between the plurality of controllers and the transceiver and outputs a standby signal to the transceiver when a standby signal is output from all of the plurality of controllers;
The plurality of controllers operate in the sleep mode, and have a wakeup control unit (13) that wakes up the controller from the sleep mode when a signal is input from the transceiver.
Among the plurality of controllers, at least the controller that first enters the sleep mode monitors the standby signal of the other controller in the plurality of controllers in the sleep mode, and the transceiver operates in the standby mode based on the standby signal of the other controller. The prohibition unit (14, 15, 16, 17) that prohibits the wakeup process according to the input signal by the wakeup control unit for a predetermined time after switching to the standby mode of the transceiver. ).

  As described above, the communication device according to the present invention determines that the transceiver is switched to the standby mode based on the standby signal of the other controller because at least the controller that first enters the sleep mode has the prohibition unit. can do. If the prohibition unit determines that the transceiver is to be switched to the standby mode, the wakeup process according to the input signal by the wakeup control unit is prohibited for a predetermined time after switching to the standby mode. . Therefore, even if a noise signal is output from the transceiver when the transceiver is switched to the standby mode, it is possible to reliably prevent the controller that was previously in the sleep mode from being erroneously woken up. become.

  The reference numerals in the parentheses merely show an example of a correspondence relationship with a specific configuration in an embodiment described later in order to facilitate understanding of the present invention, and are intended to limit the scope of the present invention. Not intended.

  Further, the technical features described in the claims of the claims other than the features described above will become apparent from the description of embodiments and the accompanying drawings described later.

It is a block diagram which shows schematic structure of the communication apparatus which concerns on 1st Embodiment. It is a block diagram which shows the internal structure of the microcomputer in the communication apparatus of FIG. It is a timing chart which shows the operation state of each part when the 1st microcomputer is switched to sleep mode at time T1, and the 2nd microcomputer is switched to sleep mode at time T3. It is a flowchart which shows the mode process which a wakeup prohibition memory | storage part performs. It is a flowchart which shows the prohibition information storage process which a wakeup prohibition memory | storage part performs. It is a flowchart which shows the 1st wakeup process which a wakeup control part performs. It is a flowchart which shows the 2nd wakeup process which a wakeup control part performs. It is a flowchart which shows the sleep process which a control part performs. It is a block diagram which shows the internal structure of the microcomputer of the communication apparatus which concerns on 2nd Embodiment. It is a flowchart which shows the count value storage process which the count value memory | storage part in FIG. 9 performs. It is a flowchart which shows the 1st wakeup process which the wakeup control part in FIG. 9 performs. It is a block diagram which shows the internal structure of the microcomputer of the communication apparatus which concerns on 3rd Embodiment. It is a flowchart which shows the filter process which the filter part in FIG. 12 performs.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

(First embodiment)
FIG. 1 is a diagram illustrating an example of a configuration of a communication device 100 according to the first embodiment. The communication device 100 is connected to, for example, a communication bus of a local area network built in the vehicle, and similarly communicates with other communication devices connected to the local area network.

  As shown in FIG. 1, the communication device 100 includes a first microcomputer 10 and a second microcomputer 20 as controllers. For example, the first microcomputer 10 serves as a verification ECU. That is, the first microcomputer 10 performs mutual communication with a portable key held by a user of the vehicle, and executes a predetermined collation process. More specifically, for example, when the vehicle is parked with the door locked, the first microcomputer 10 is woken up at a predetermined time interval by a timer (not shown) and transmits radio waves to the portable key. When necessary processing such as transmission / reception of radio waves and verification processing is completed, the mode shifts to a sleep mode in which main operations are stopped. Thus, since the first microcomputer 10 needs to be activated and operated when the vehicle is parked, that is, when the ignition switch is turned off, the first microcomputer 10 is directly supplied with power from the in-vehicle battery. . When the first microcomputer 10 is in the sleep mode and receives a signal from another communication device, the first microcomputer 10 wakes up to operate in cooperation with the microcomputer included in the other communication device. It is configured. This also applies to the second microcomputer described below.

  For example, the second microcomputer 20 serves as a power supply ECU. That is, the second microcomputer 20 is activated by a signal from the first microcomputer 10 when the first microcomputer 10 wakes up or when the first microcomputer 10 determines that the verification is established, and various on-vehicle devices (for example, Power supply to the touch sensor, door lock motor, engine starter, etc., provided on the doorknob. Thus, a user having an authorized mobile key can release the door lock by touching the touch sensor, or can start the engine by pressing the start button of the engine. The second microcomputer 20 is used when, for example, the verification is not established in the first microcomputer 10 or when a predetermined time elapses without the user performing an operation for getting on after the start of power supply. Stop the power supply to the in-vehicle device and shift to the sleep mode.

  As a microcomputer included in another communication device, for example, there is a microcomputer that plays a role as a body ECU. For example, when the first microcomputer 10 is verified and the touch sensor provided in the door knob of the vehicle is energized, this microcomputer detects the user's operation on the touch sensor and locks the door. Execute processing to unlock. Therefore, the microcomputer serving as the body ECU is activated by the wake-up signal output from the first microcomputer 10 when the first microcomputer 10 wakes up or when the first microcomputer 10 determines that the verification is established. Is done.

  The first microcomputer 10 and the second microcomputer 20 have signal output terminals Tx1 and Tx2, standby signal output terminals STB1 and STB2, signal input terminals Rx1 and Rx2, and a standby signal input terminal for inputting a standby signal of the other microcomputer, respectively. P1 and P2. When there is no signal to be transmitted, the first microcomputer 10 and the second microcomputer 20 output a high level signal from the signal output terminals Tx1 and Tx2. The first microcomputer 10 and the second microcomputer 20 output a low-level normal signal from the standby signal output terminals STB1 and STB2 in the normal mode in which normal operation is performed, and output a high-level standby signal in the sleep mode. To do. It is also possible to set the normal signal output to a high level and the standby signal output to a low level.

  The first microcomputer 10 and the second microcomputer 20 communicate with other communication devices according to a so-called CAN protocol. Therefore, the first microcomputer 10 and the second microcomputer 20 have a communication control unit 12 corresponding to a so-called CAN controller, as shown in FIG. Since the first microcomputer 10 and the second microcomputer 20 have the same internal configuration, only the internal configuration of the first microcomputer 10 is shown in FIG. The first microcomputer 10 includes a control unit 11 that performs various processes in cooperation with other microcomputers by communicating with the other microcomputers via the communication control unit 12.

  As is well known, the communication control unit 12 as a CAN controller includes a message box for storing data and messages transmitted and received between microcomputers. Then, the communication control unit 12 creates a communication frame based on the stored value of the message box. Further, the communication control unit 12 performs transmission control for transmitting the created communication frame to the communication bus via the transceiver 50 described later, reception control for extracting data and messages from the communication frame received by the transceiver 50, and the communication bus. In accordance with the CAN protocol, such as arbitration control of transmission right (bit-by-bit non-destructive arbitration) when a communication frame collides in the Tx coupling circuit 30 described later, error detection and notification related to communication frame transmission / reception, etc. Execute communication control.

  When there is data or a message to be transmitted to another microcomputer, the control unit 11 specifies priority information (ID code) indicating a priority corresponding to the transmission content, and communicates these message and ID code. The message is stored in the message register and ID code register of the message box of the control unit 12. In this way, when a message for transmission is stored in the message box of the communication control unit 12 by the control unit 11, the communication control unit 12 performs transmission control based on the stored value (ID code and message) of the message box. A communication frame is created and transmitted through the transceiver 50. In addition to creating a message for transmission, the control unit 11 performs the above-described verification process and performs a control process for controlling the in-vehicle device. When the control unit 11 completes necessary processes and sleeps, the first microcomputer 10 shifts to the sleep mode.

  In the communication apparatus 100 according to the present embodiment, a configuration in which only one transceiver 50 is provided for the two microcomputers 10 and 20 is employed. For this reason, the communication device 100 combines (aggregates) the Tx coupling circuit 30 that combines (arbitrates) signals indicating communication frames transmitted from the two microcomputers 10 and 20 and the standby signals from the two microcomputers 10 and 20. STB coupling circuit 40 is provided.

  When a signal indicating a communication frame is output from either the first microcomputer 10 or the second microcomputer 20, the Tx coupling circuit 30 outputs a signal indicating the communication frame to the transmission terminal TxT of the transceiver 50. The Tx coupling circuit 30 includes an AND gate, and when communication frames from the first microcomputer 10 and the second microcomputer 20 collide, a communication frame having a higher priority is transmitted.

  The STB coupling circuit 40 outputs a standby signal to the standby terminal STBT of the transceiver 50 when a high-level standby signal is output from both the first microcomputer 10 and the second microcomputer 20. In other words, when the standby signal is output from only one of the first microcomputer 10 and the second microcomputer 20, the STB coupling circuit 40 performs the normal operation, and thus the transceiver 50 A low level normal signal is output to the standby terminal STBT.

  The transceiver 50 has two types of potential differences in the two-wire communication line of the communication bus according to the logic level of the signal indicating the communication frame output from the signal output terminals Tx1 and Tx2 of the first microcomputer 10 or the second microcomputer 20. And a signal of “1” or “0” is communicated on the communication bus. Further, the transceiver 50 converts the potential difference generated on the communication bus into a signal indicating a communication frame, and outputs the signal to the signal input terminals Rx1 and Rx2 of the first microcomputer 10 and the second microcomputer 20 from the reception terminal RxT.

  The transceiver 50 operates in a normal mode that enables transmission and reception of the above-described signal when a low-level normal signal is input to the standby terminal STBT. However, when a high-level standby signal is input to the standby terminal STBT, the transceiver 50 enters a standby mode in which power consumption is reduced by stopping signal transmission. However, even in the standby mode, the transceiver 50 can receive signals.

  Here, as shown in the timing chart of FIG. 3, in the transceiver 50, when the standby signal is input to the standby terminal STBT and the operation mode is switched from the normal mode to the standby mode, the signal level of the reception terminal RxT becomes indefinite. In some cases, a noise signal is output from the receiving terminal RxT toward the first and second microcomputers 10 and 20.

  As shown in FIG. 1, in a configuration in which two microcomputers 10 and 20 share one transceiver 50, each microcomputer 10 and 20 may enter a sleep mode and output a standby signal at different times. Yeah. In this case, the transceiver 50 shifts from the normal mode to the standby mode when a standby signal is output from the microcomputer that finally enters the sleep mode. In this way, the microcomputer that finally enters the sleep mode can grasp the timing of switching to the standby mode because the transceiver 50 is switched to the standby mode by the standby signal output by itself. Therefore, for example, if the signal output from the reception terminal RxT of the transceiver 50 is ignored in accordance with the switching of the transceiver 50 to the standby mode, the noise signal is mistaken as a signal from another communication device, You can prevent accidental wake-up.

  However, the microcomputer that is in the sleep mode first cannot know when the transceiver 50 is switched to the standby mode. For this reason, there is a possibility that the noise signal output from the reception terminal RxT of the transceiver 50 may wake up accidentally. Then, there is a possibility that the microcomputer that has woken up accidentally transmits a signal to the communication bus and wakes up other microcomputers unnecessarily.

  Therefore, in the communication apparatus 100 according to the present embodiment, the first microcomputer 10 and the second microcomputer 20 are each provided with standby signal input terminals P1 and P2 for taking in a standby signal output from the other microcomputer. Further, based on the standby signal from the other microcomputer, it is determined that the transceiver 50 is switched to the standby mode, and the microcomputer responds to the input data for a predetermined time after the transceiver 50 is switched to the standby mode. A prohibition section that prohibits wake-up is provided. As a result, it is possible to prevent the microcomputer previously in the sleep mode from being erroneously woken up by the noise signal output from the reception terminal RxT of the transceiver 50.

  Hereinafter, an internal configuration including the prohibition part of the first microcomputer 10 and the second microcomputer 20 will be described with reference to FIG. However, in this embodiment, since the internal configuration of the first microcomputer 10 and the second microcomputer 20 is common, the first microcomputer 10 will be described as an example.

  As illustrated in FIG. 2, the first microcomputer 10 includes a wakeup control unit 13 that wakes up the control unit 11 that has entered the sleep mode. The wake-up control unit 13 operates when the control unit 11 is in the sleep mode. When a signal is input from the transceiver 50 through the signal input terminal Rx1, the wake-up control unit 13 executes a wake-up process that causes the control unit 11 to wake up. Further, the wakeup control unit 13 determines that a predetermined time has elapsed since the previous wakeup based on another wakeup factor other than the signal input from the transceiver 50, for example, a measurement time by a timer (not shown). Even in the case of the failure, the control unit 11 is woken up.

  The wake-up prohibition storage unit 14 corresponds to the above-described prohibition unit, and is activated when the control unit 11 enters the sleep mode, and can operate, while the control unit 11 wakes up from the sleep mode. When normal mode is entered, the operation is stopped. During startup, the wakeup prohibition storage unit 14 has changed the signal output from the standby signal output terminal STB2 of the second microcomputer 20 from the normal signal to the standby signal based on the signal input from the standby signal input terminal P1. In other words, when the rising edge of a signal from a low level signal to a high level signal is detected, wakeup prohibition information is held for a predetermined time.

  Note that the wakeup prohibition storage unit 14 can hold the wakeup prohibition information using, for example, a RAM or a register in the first microcomputer 10. Further, the wakeup control unit 13 and the wakeup prohibition storage unit 14 may be configured by dedicated hardware or may be configured as software executed by the CPU of the first microcomputer 10. When configured as software, the CPU of the first microcomputer 10 only needs to execute software that functions as the wakeup control unit 13 and the wakeup prohibition storage unit 14 during the sleep mode.

  For example, as shown in the timing chart of FIG. 3, when the first microcomputer 10 enters the sleep mode before the second microcomputer 20 and then the second microcomputer 20 also enters the sleep mode, a standby signal is output from the second microcomputer 20. When output, the transceiver 50 enters a standby mode by a standby signal from both the microcomputers 10 and 20. For this reason, the wakeup prohibition storage unit 14 of the first microcomputer 10 can determine whether or not the transceiver 50 is switched to the standby mode based on the standby signal of the second microcomputer 20. The wake-up prohibition storage unit 14 can hold the wake-up prohibition information for a predetermined time after the transceiver 50 is switched to the standby mode by determining that the transceiver 50 is switched to the standby mode. Become.

  When the wake-up control unit 13 inputs a signal from the transceiver 50 via the signal input terminal Rx1, the wake-up control unit 13 refers to the wake-up prohibition storage unit 14 and determines whether the wake-up prohibition storage unit 14 holds wake-up prohibition information. To check. When the wakeup prohibition information is held, the wakeup control unit 13 does not execute the wakeup process even if a signal is input from the reception terminal RxT of the transceiver 50. Therefore, it is possible to prevent the first microcomputer 10 from being erroneously woken up by the noise signal output from the reception terminal RxT of the transceiver 50.

  A more detailed operation in the communication apparatus 100 configured as described above will be described with reference to the flowcharts of FIGS. In the description of each flowchart, the timing chart of FIG. 3 is referred to as appropriate.

  The flowchart of FIG. 4 relates to the mode process executed by the wakeup prohibition storage unit 14. The processing shown in this flowchart is executed when a mode command of either the start mode or the stop mode is issued from the control unit 11 to the wakeup prohibition storage unit 14.

  First, in step S <b> 100, the wakeup prohibition storage unit 14 receives a mode command from the control unit 11. In subsequent step S110, it is determined whether the received mode command is a start command or a stop command. If it is determined that the command is a start command, the process proceeds to step S120, and the wakeup prohibition storage unit 14 sets the operation mode to the start mode. On the other hand, when it determines with it being a stop command, it progresses to step S130 and the wakeup prohibition memory | storage part 14 sets an operation mode to a stop mode.

  When the control unit 11 shifts to the sleep mode, the control unit 11 outputs a start command to the wakeup prohibition storage unit 14. When the control unit 11 wakes up from the sleep mode and shifts to the normal mode, the control unit 11 issues a stop command to the wakeup prohibition storage unit 14. Output. Therefore, as shown in the timing chart of FIG. 3, when the operation mode of the control unit 11 (first microcomputer 10) is the normal mode (before time T1), the operation mode of the wakeup prohibition storage unit 14 is set to the stop mode. Is set. At time T1, when the operation mode of the control unit 11 is switched to the sleep mode, the operation mode of the wakeup prohibition storage unit 14 becomes the activation mode. Thus, the wakeup prohibition storage unit 14 is in the start mode only while the control unit 11 is in the sleep mode, and can hold the wakeup prohibition information based on the standby signal of another microcomputer. .

  The flowchart of FIG. 5 relates to the prohibition information storage process executed by the wakeup prohibition storage unit 14. The processing shown in this flowchart is executed when the wakeup prohibition storage unit 14 detects that the signal taken in from the standby signal input terminal P1 rises from a low level (normal signal) to a high level (standby signal). .

  First, in step S200, it is determined whether or not the operation mode is set to the start mode. At this time, if it is determined that the start mode is set, the process proceeds to step S210. If it is determined that the stop mode is set, the prohibition information storage process shown in the flowchart of FIG.

  In step S210, the wake-up prohibition information is held in an appropriate storage unit such as a RAM or a register of the first microcomputer 10. In a succeeding step S220, it is determined whether or not a predetermined time has elapsed since the wakeup prohibition information is held. This predetermined time is set to a time during which the noise signal output from the reception terminal RxT can be masked when the transceiver 50 is switched to the standby mode. If it is determined that the predetermined time has elapsed, in step S230, the held wake-up prohibition information is cleared, and the prohibition information storage process shown in FIG. 5 ends.

  When the output of the standby signal from the standby signal output terminal STB2 of the second microcomputer 20 is started at time T3 as shown in the timing chart of FIG. 3 by the prohibition information storage processing shown in FIG. 5, from time T3, The wakeup prohibition storage unit 14 holds wakeup prohibition information. This wake-up prohibition information is cleared at time T4 when a predetermined time has elapsed from time T3.

  The flowchart of FIG. 6 relates to the first wakeup process executed by the wakeup control unit 13. In the first wake-up process shown in this flowchart, the control unit 11 is in the sleep mode, and the wake-up control unit 13 detects the occurrence of an edge when the signal input from the signal input terminal Rx1 changes. When executed.

  First, in step S300, the wakeup control unit 13 refers to the wakeup prohibition storage unit 14 and confirms whether wakeup prohibition information is held. In step S310, based on the confirmation result in step S300, it is determined whether wakeup prohibition information is held in the wakeup prohibition storage unit 14. If it is determined in this determination process that the wake-up prohibition information is held, the first wake-up process shown in the flowchart of FIG. 6 is terminated. For this reason, as shown in the timing chart of FIG. 3, the wakeup prohibition information is held in the wakeup prohibition storage unit 14 during the period from time T3 to time T4. Even if a change in the signal input from the terminal Rx1 is detected, the control unit 11 is not woken up. For this reason, the control unit 11 can maintain the sleep mode even when a noise signal is output from the reception terminal RxT due to the transceiver 50 being switched to the standby mode at time T3.

  On the other hand, if the wakeup control unit 13 determines that the wakeup prohibition information is not held in the wakeup prohibition storage unit 14 in the determination process of step S310, the process proceeds to step S320.

  In step S320, the wakeup control unit 13 causes the control unit 11 to wake up. Thereby, the control unit 11 is switched from the sleep mode to the normal mode, and starts a normal control operation.

  In subsequent step S330, the control unit 11 switched to the normal mode outputs a stop command to the wake-up prohibition storage unit 14. As a result, the wakeup prohibition storage unit 14 stops operating. Moreover, the control part 11 starts the communication control part 12 in step S340. That is, the communication control unit 12 is configured to stop in conjunction with the transition to the sleep mode of the control unit 11 and to be activated in conjunction with the transition to the normal mode. Further, in step S350, the control unit 11 outputs a normal signal from the standby signal output terminal STB1 to the transceiver 50. As a result, the operation mode of the transceiver 50 is switched from the standby mode to the normal mode, and the transceiver 50 can perform signal transmission processing. In step S360, the control unit 11 sends a wake-up signal to the communication bus via the communication control unit 12 to wake up the microcomputers of other communication devices connected to the local area network.

  The flowchart in FIG. 7 relates to the second wakeup process executed by the wakeup control unit 13. The second wake-up process shown in this flowchart is performed when the control unit 11 is in the sleep mode and the wake-up control unit 13 detects another wake-up factor other than the signal input from the transceiver 50. To be executed.

  In the second wake-up process shown in the flowchart of FIG. 7, the processes from steps S400 to S440 are executed in order. The processes in these steps are the same as those in steps S320 to S360 in the flowchart of FIG. It is the same as the processing. That is, when another wake-up factor other than the signal input from the transceiver 50 is detected, the wake-up control unit 13 immediately wakes up the control unit 11, thereby causing the control unit 11 to Each part of the microcomputer 10 is shifted to a state in which it can be normally operated. That is, when another wake-up factor is detected, the wake-up control unit 13 wakes up the control unit 11 regardless of whether wake-up prohibition information is held in the wake-up prohibition storage unit 14 or not. Let

  The flowchart in FIG. 8 relates to the sleep process executed by the control unit 11. The sleep process shown in this flowchart is executed when all necessary processes are completed in the control unit 11. The timing chart of FIG. 3 shows how the first microcomputer 10 is switched to the sleep mode at time T1.

  First, in step S500, the control unit 11 stops the communication control unit 12. In the subsequent step S510, a standby signal is output from the standby signal output terminal STB1 toward the transceiver 50. Note that the output of the standby signal from the control unit 11 is continued even after the control unit 11 enters the sleep mode.

  However, even when the first microcomputer 10 starts outputting the standby signal at time T1 in the timing chart of FIG. 3, the transceiver 50 is not switched to the standby mode and remains in the normal mode. This is because the second microcomputer 20 is still operating and a normal signal is output from the standby signal output terminal STB2 of the second microcomputer 20.

  In step S520, the control unit 11 outputs an activation command to the wake-up prohibition storage unit 14. As a result, the wake-up prohibition storage unit 14 enters an activation mode and starts operation. Moreover, the control part 11 transfers to sleep mode in step S530. In the subsequent step S540, the wakeup control unit 13 sets to prohibit execution of the wakeup process according to the input signal. In step S550, the wakeup control unit 13 determines whether or not a predetermined time has elapsed since the setting of prohibiting execution of the wakeup process. If it is determined that the predetermined time has elapsed, the process proceeds to step S560, and the wakeup control unit 13 cancels the prohibition of execution of the wakeup process according to the input signal.

  For a predetermined time after the control unit 11 shifts to the sleep mode, the wakeup control unit 13 prohibits the execution of the wakeup process according to the input signal, so that the first microcomputer 10 becomes the second microcomputer. Even when the sleep mode is entered later than 20, it is possible to prevent the normal mode from being restored by the noise signal from the transceiver 50.

(Second Embodiment)
Next, a communication apparatus according to the second embodiment of the present invention will be described. In the following description, parts different from those of the communication device according to the first embodiment described above will be mainly described, and common parts will be given the same reference numerals and description thereof will be omitted.

  In the first embodiment described above, when the wakeup prohibition storage unit 14 detects a change in the signal output from the standby signal output terminal STB2 of the second microcomputer 20, the wakeup prohibition information is retained for a predetermined time. It was.

  On the other hand, in the present embodiment, as shown in FIG. 9, a count value storage unit 15 is provided as a prohibition unit instead of the wakeup prohibition storage unit 14. Further, the first microcomputer 10 is provided with a timer 16 that counts the passage of time as one of the components of the prohibition unit. When the count value storage unit 15 determines that the transceiver 50 is switched to the standby mode based on the change in the signal output from the standby signal output terminal STB2 of the second microcomputer 20, the count value of the timer 16 at that time is read. And save.

  The flowchart of FIG. 10 shows the count value storage process executed by the count value storage unit 15. This count value storing process counts that the signal fetched from the standby signal input terminal P1 rises from the low level (normal signal) to the high level (standby signal), similarly to the wakeup prohibition information storing process of FIG. It is executed when the value storage unit 15 detects it.

  Similarly to the wakeup prohibition storage unit 14, the count value storage unit 15 is activated when the control unit 11 enters the sleep mode, and is stopped when the control unit 11 shifts to the normal mode. Therefore, in the count value storage process, first, in step S600, it is determined whether or not the count value storage unit 15 is in the startup mode. If it is determined in this determination process that the activation mode is selected, the process proceeds to step S610. In step S610, the count value storage unit 15 reads and stores the count value of the timer 16.

  When the signal input from the signal input terminal Rx1 changes to detect the occurrence of an edge, the wakeup control unit 13 executes a first wakeup process shown in the flowchart of FIG.

  First, in step S700, the wake-up control unit 13 refers to the count value storage unit 15 and confirms the stored count value of the timer 16. In step S710, it is determined whether the count value is stored based on the confirmation result in step S700. In this determination process, if it is determined that the count value is stored, the process proceeds to step S720. On the other hand, if it is determined that the count value is not stored, the process proceeds to step S740, and the control unit 11 is woken up. When the count value is not stored in the count value storage unit 15, the transceiver 50 is not shifted to the standby mode, and the signal input to the wakeup control unit 13 can be regarded as a wakeup signal from another microcomputer. It is.

  In step S720, the wakeup control unit 13 reads the latest count value of the timer 16. In step S730, it is determined whether or not the difference between the count value stored in the count value storage unit 15 and the latest read count value indicates that a predetermined time or more has elapsed. In this determination process, if the difference between the two count values indicates only a lapse of time less than the predetermined time, that is, if it is determined “NO”, the first wake-up process shown in the flowchart of FIG. Thereby, the wake-up control unit 13 can be prevented from executing the wake-up process according to the input signal until a predetermined time elapses after the transceiver 50 shifts to the standby mode.

  On the other hand, if it is determined in step S730 that the difference between the two count values is equal to or longer than the predetermined time, that is, "YES", the process proceeds to step S740. Each process of steps S740 to S780 causes the control unit 11 to wake up and the waked up control unit 11 in the same manner as the processes of steps S320 to S360 of the first wakeup process of FIG. 6 of the first embodiment. Thus, each part of the first microcomputer 10 is shifted to a state in which it can normally operate.

  However, among steps S740 to S780, the process of step S750 is slightly different from the first wake-up process of the first embodiment. That is, the count value storage unit 15 of the present embodiment has only a function of storing the count value of the timer 16 at the time when the transceiver 50 is switched to the standby mode, and does not have a function of clearing the count value. Therefore, when a stop command is output to the count value storage unit 15 in step S750, a count value clear command is also output.

  Even in the communication device according to the second embodiment as described above, similarly to the communication device 100 according to the first embodiment, the noise output from the reception terminal RxT of the transceiver 50 when the transceiver 50 shifts to the standby mode. It is possible to prevent the signal from being waked up accidentally.

(Third embodiment)
Next, a communication apparatus according to the third embodiment of the present invention will be described. In the following description, parts different from those of the communication device according to the first embodiment described above will be mainly described, and common parts will be given the same reference numerals and description thereof will be omitted.

  As shown in FIG. 12, the communication apparatus according to the present embodiment is different from the communication apparatus according to the first embodiment in that a filter unit 17 is provided as a prohibition unit. The filter unit 17 is provided between the signal input terminal Rx1 and the wakeup control unit 13. When the filter unit 17 determines that the transceiver 50 is switched to the standby mode based on a change in the signal output from the standby signal output terminal STB2 of the second microcomputer 20, the signal is output for a predetermined time from the determination time. The transmission of the signal input from the input terminal Rx1 to the wakeup control unit 13 is cut off. That is, even if the signal input to the signal input terminal Rx1 changes, the filter unit 17 outputs a signal that does not change to the wakeup control unit 13.

  The flowchart of FIG. 13 shows the filter processing executed by the filter unit 17. This filter process is similar to the wake-up prohibition information storage process of FIG. 5 in that the filter unit 17 indicates that the signal taken in from the standby signal input terminal P1 has risen from the low level (normal signal) to the high level (standby signal). Executed when is detected.

  Similarly to the wakeup prohibition storage unit 14, the filter unit 17 is activated when the control unit 11 enters the sleep mode, and is stopped when the control unit 11 shifts to the normal mode. Therefore, in the filter process shown in FIG. 13, first, in step S800, it is determined whether or not the filter unit 17 is in the startup mode. If it is determined in this determination process that the activation mode is selected, the process proceeds to step S810. In step S810, filtering by the filter unit 17 is started. During the filtering, as described above, even if the signal input to the signal input terminal Rx1 changes, the change is not transmitted to the wakeup control unit 13.

  In a succeeding step S820, it is determined whether or not a predetermined time has elapsed since the filtering was started. If it is determined that the predetermined time has elapsed, the filtering by the filter unit 17 is stopped in step S830. Therefore, thereafter, the signal input to the signal input terminal Rx1 is output to the wakeup control unit 13 as it is.

  As described above, in the communication device according to the third embodiment, transmission of the signal input to the signal input terminal Rx1 to the wakeup control unit 13 is interrupted for a predetermined time after the transceiver 50 is switched to the standby mode. doing. For this reason, when the transceiver 50 shifts to the standby mode, it is possible to prevent erroneous wake-up due to the noise signal output from the reception terminal RxT of the transceiver 50.

  The preferred embodiments of the present invention have been described above, but the present invention is not limited to the above-described embodiments, and various modifications can be made without departing from the spirit of the present invention.

  For example, in each of the above-described embodiments, the configuration in which one transceiver is provided for two microcomputers has been described. However, the transceiver may be shared by three or more microcomputers. In this case, when each microcomputer enters the sleep mode, it captures the signal output from the standby signal output terminal of all other microcomputers, detects the change, and outputs the standby signal from all other microcomputers. The detection result is stored until it is detected. When all the detection results indicate the output of the standby signal, the prohibition unit prohibits the wake-up process based on the signal input from the signal input terminal for a predetermined time from that point. To do.

  Moreover, in each embodiment mentioned above, the prohibition part was provided in each microcomputer. However, in the case of multiple microcomputers sharing a transceiver, if the order of shifting to the sleep mode is determined based on the relationship between the roles and functions to be performed, the microcomputer that enters the sleep mode is provided with a prohibition section first. In addition, the microcomputer that shifts to the sleep mode may be configured not to include the prohibition unit.

DESCRIPTION OF SYMBOLS 10 1st microcomputer 11 Control part 12 Communication control part 13 Wakeup control part 14 Wakeup prohibition memory | storage part 15 Count value memory | storage part 16 Timer 17 Filter part 20 2nd microcomputer 30 Tx coupling circuit 40 STB coupling circuit 50 Transceiver

Claims (7)

A communication device (100) for communicating with another communication device via a communication bus,
A plurality of controllers (10, 20) for generating and outputting a signal to be transmitted and processing an input signal, and outputting a standby signal in the sleep mode;
Sending signals output from the plurality of controllers to the communication bus, receiving signals sent from the other communication devices to the communication bus, and inputting the signals to the plurality of controllers, the standby A transceiver (50) that switches from a normal operation mode to a standby mode to stop transmission operation when a signal is input;
A coupling unit (40) that is interposed between the plurality of controllers and the transceiver, and outputs the standby signal to the transceiver when the standby signal is output from all of the plurality of controllers;
The plurality of controllers operate in a sleep mode, and have a wakeup control unit (13) that wakes up the controller from a sleep mode when a signal is input from the transceiver,
Among the plurality of controllers, at least the controller that is in the sleep mode first, in the sleep mode, monitors a standby signal of another controller in the plurality of controllers, and based on the standby signal of the other controller, the transceiver A prohibition unit (14,) for prohibiting a wakeup process according to an input signal by the wakeup control unit for a predetermined time after the transceiver is switched to the standby mode. 15, 16, 17). The prohibition unit includes a storage unit (14) that holds wake-up prohibition information for a predetermined time after the transceiver is switched to the standby mode when it is determined that the transceiver is switched to the standby mode.
2. The communication according to claim 1, wherein the wakeup control unit refers to the storage unit and does not execute a wakeup process according to an input signal while the wakeup prohibition information is held in the storage unit. apparatus. The prohibited part is
A timer (16) for counting the passage of time;
A count value storage unit (15) for holding a count value of the timer when the transceiver is switched to a standby mode, the wake-up control unit includes a latest count value by the timer, and the count value storage unit The wake-up process according to the input signal is not executed until it is determined that a predetermined time has elapsed since the transceiver was switched to the standby mode with reference to the count value held in Communication device.   2. The communication device according to claim 1, wherein the prohibition unit includes a filter unit (17) that blocks a signal input from the transceiver to the wakeup control unit for a predetermined time after the transceiver is switched to the standby mode. .   The wake-up control unit causes the controller to wake up by another wake-up factor other than a signal input from the transceiver, and when the other wake-up factor is detected, The communication apparatus according to claim 1, wherein the wake-up process is executed even before a predetermined time has elapsed since switching to the mode.   The said wakeup control part stops the wakeup process according to the input data for a predetermined time after the corresponding controller starts the output of the standby signal. Communication equipment.   The communication device according to claim 1, wherein the prohibition unit is activated when a corresponding controller enters a sleep mode, and is stopped when the controller wakes up from the sleep mode.

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