JP4082067B2 - Watchdog monitoring device - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a watchdog monitoring device provided in a watchdog circuit of a vehicle-mounted device connected to a network.
[0002]
[Prior art]
Conventionally, a device (vehicle mounting device) provided in a vehicle is controlled mainly by a CPU that is a control means, and the vehicle mounting device is configured to operate based on the operation of the CPU. ing.
[0003]
This CPU is configured to be able to form a wake-up mode in which a normal operation is performed and a sleep mode in which the operation is restricted to reduce power consumption. The CPU is configured to input an ignition on signal when the ignition switch is turned on, and is configured to shift the CPU to a sleep mode when the ignition is off without inputting the ignition on signal. . On the other hand, when the ignition is turned on when the ignition on signal is inputted, the CPU in the sleep mode is returned to the wake-up mode.
[0004]
This apparatus is provided with a watchdog circuit for monitoring the CPU operation in order to improve the reliability of the CPU operation.
[0005]
The watchdog circuit includes a watchdog IC, and the watchdog IC is configured to receive a periodic signal that is periodically output from the CPU. The watchdog IC is configured to output a reset signal to the CPU when the periodic signal is abnormal, and is configured to be able to reset the CPU by the reset signal.
[0006]
The watchdog IC is configured to input an active signal from the ignition switch signal. When the ignition switch is turned on, the watchdog permission / prohibition terminal receives a monitoring permission signal, and when the ignition is turned off. The enable / inhibit terminal of the watchdog IC and the ignition switch are connected by an active signal input circuit so that a signal for prohibiting monitoring is input.
[0007]
When the monitoring permission signal based on the active signal is input, the normal monitoring operation described above is performed. On the other hand, when the monitoring permission signal is stopped, the monitoring permission signal is stopped. The reset signal is prohibited from being output.
[0008]
When the ignition switch is turned off, the active signal is stopped and no reset signal is output from the watchdog IC.
[0009]
On the other hand, a signal necessary for controlling the vehicle-mounted device is exchanged via a communication signal via a network.
[0010]
In this case, the ignition switch signal is also put on a network communication signal from the efficiency of signal exchange such as omission of the wire harness, and the CPU which is the control means of the vehicle-mounted device receives the ignition switch signal as a communication signal. .
[0011]
Then, an active signal of the watchdog IC from the CPU is connected between the watchdog permission / inhibition terminal and the CPU by an active signal input circuit.
[0012]
In the sleep mode, no active signal is input from the CPU, and no periodic signal is input. In this case, no reset signal is output.
[0013]
[Problems to be solved by the invention]
However, in such a monitoring apparatus, since the watchdog circuit monitors the CPU operation based on the active signal input from the CPU, external noise or noise is detected in the CPU even though the CPU is in the wake-up mode. When an unexpected abnormal state (runaway) occurs due to a bug or the like, it is possible that an active signal from the CPU stops.
[0014]
At this time, since an active signal is not input to the watchdog circuit, even if an abnormal state occurs in the CPU, the watchdog circuit does not output a reset signal to the CPU and cannot reset the CPU. For this reason, there is a risk that other on-vehicle devices that exchange communication signals with the CPU via the network may also malfunction.
[0015]
In addition, in a vehicle-mounted device that is controlled independently by the CPU without using a network, a signal for setting the CPU in the sleep mode to the wake-up mode is input to the CPU regardless of the ignition switch signal. There are some which are configured to perform in response to a signal to turn on an operation switch or a sensor of this vehicle-mounted device.
[0016]
As described above, even in the vehicle-mounted device that is independently controlled by the CPU, when the abnormal state occurs in the CPU, the watchdog circuit cannot reset the CPU. Therefore, the vehicle-mounted device that is controlled independently. May malfunction.
[0017]
The present invention has been made in view of such a conventional problem, and an object of the present invention is to provide a watchdog monitoring apparatus capable of further improving the reliability.
[0018]
[Means for Solving the Problems]
In order to solve the above-mentioned problem, in the watchdog monitoring apparatus according to claim 1 of the present invention, the wake-up mode in which normal operation is performed and the sleep mode in which operation restriction is performed on a vehicle-mounted apparatus connected via a network. And a control circuit such as a CPU whose mode is changed at the time, a watchdog circuit for monitoring the operation of the control means, and a communication circuit for exchanging communication signals with other devices with the control means. When the circuit detects an abnormality in the periodic signal input from the control unit in a state where the monitoring permission signal based on the active signal output from the control unit is input, the circuit outputs a reset signal for resetting the control unit. While the input of the monitoring permission signal is stopped based on the stop of the active signal, the input state of the periodic signal is In the watchdog monitoring device that prohibits the output of the reset signal to the control means, a hold circuit that continuously outputs a hold signal for at least a predetermined time when a communication state is detected from the communication signal, and the hold circuit An OR for inputting the holding signal output from the circuit and the active signal from the control means, and outputting the monitoring permission signal to the watchdog circuit in a state where at least one of the holding signal and the active signal is input. And a circuit.
[0019]
That is, when communicating with another on-vehicle device via a network, the communication state is detected from the communication signal. For this reason, the hold signal is continuously output from the hold circuit for a predetermined time and is input to the OR circuit. Then, the OR circuit outputs a monitoring permission signal to the watch dock circuit at least while the holding signal is input, that is, regardless of the presence or absence of an active signal from the control means.
[0020]
For this reason, even when a control unit such as a CPU reliably communicates in the wake-up mode and an unexpected abnormal situation occurs and the active signal from the control unit is stopped, the watchdog circuit Monitoring of the control means is continued.
[0021]
Further, in the watchdog monitoring device according to claim 2, the control means and the vehicle device controlled by the control means are connected, while the OR circuit includes the holding signal and the active signal, 2. The watch according to claim 1, wherein a signal for operating the vehicle device is input, and the monitoring permission signal is output to the watch dock circuit in a state where at least one of these signals is input. Dock monitoring device.
[0022]
That is, a vehicle device that is controlled and operated independently from the others by the control means is provided, and the vehicle device is controlled by the control means. For this reason, while outputting the signal for operating this apparatus for vehicles, this signal is inputted in the OR circuit. Then, this OR circuit outputs the monitoring permission signal at least while the signal for operating the vehicle device is input, that is, regardless of the presence of the active signal from the control means and the holding signal from the holding circuit. Output to the circuit.
[0023]
Therefore, even when an unexpected abnormal situation occurs and the active signal from the control means is stopped when the control device such as the CPU is in the wake-up mode, the vehicle device is operated. Monitoring of the control means by the dock circuit is continued.
[0024]
In addition, the monitorability of the control means such as the CPU during the single operation of the vehicle-mounted device that is controlled independently of the other that does not require communication with other vehicle-mounted devices is also improved.
[0025]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, an embodiment of the present invention will be described with reference to the drawings. FIG.1 and FIG.2 is a circuit diagram which shows the vehicle mounting apparatus 1 provided with the watchdog monitoring apparatus concerning this Embodiment.
[0026]
The vehicle mounting device 1 is a device that operates a closure, a sunroof, a small lamp, and a head wrap, and is configured to be able to communicate with another vehicle mounting device 12 via an in-vehicle LAN 11. The vehicle-mounted device 1 is mainly configured by a CPU 13 as a control means, and the CPU 13 can form a wake-up mode for performing a normal operation and a sleep mode for greatly restricting the operation to reduce power consumption. It is comprised so that a mode change can be carried out between both modes.
[0027]
The vehicle mounting apparatus 1 is provided with a watchdog circuit 21 that monitors the operation of the CPU 13. The watchdog circuit 21 includes a watchdog IC 22, and the CK1 terminal 23 and the CK2 terminal 24 of the watchdog IC 22 are connected to the output port 25 of the CPU 13. The output port 25 is configured to output a watchdog output as a periodic signal having a fixed period, and this watchdog output is configured to be stopped when the CPU 13 shifts to the sleep mode. Yes.
[0028]
The watchdog IC 22 is supplied with battery power via a capacitor 33 between the VCC terminal 31 and the GND terminal 32, and the watchdog output to be monitored is supplied to the CTW terminal 34 and the CTP terminal 35 of the watchdog IC 22. Are grounded via capacitors 36 and 37 for determining the monitoring time and the monitoring cycle.
[0029]
The watchdog IC 22 is provided with a RESET output terminal 41 for outputting a reset signal, and the RESET output terminal 41 is also grounded via a capacitor 42. The RESET output terminal 41 is connected to a reset terminal 43 of the CPU 13 so that the CPU 13 can be reset when the watchdog IC 22 outputs a reset signal.
[0030]
The watchdog IC 22 is provided with an INH terminal 51, and the INH terminal 51 is pulled up to a battery power supply via a pull-up resistor 52. The watchdog IC 22 is configured to monitor the watchdog output input from the CK1 terminal 23 and the CK2 terminal 24 while “L” as a monitoring permission signal is input to the INH terminal 51. When the input watchdog output detects an abnormality such that the monitoring time input does not change in the monitoring period, a reset signal is output from the RESET output terminal 41 to reset the CPU 13.
[0031]
On the other hand, while the “H” as the inhibition signal is input to the INH terminal 51, the watchdog IC 22 does not change the RESET regardless of the state of the watchdog output input from the CK1 terminal 23 and the CK2 terminal 24. The output signal from the output terminal 41 to the CPU 13 is prohibited.
[0032]
The INH terminal 51 is connected to the collectors of first to third digital transistors 61 to 63 (hereinafter referred to as “Digitra 61 to 63”) incorporating a bias resistor. Each Digitra 61-63 is composed of an NPN transistor, and each emitter is grounded. The base of the first digita 61 is connected to the output port 65 of the CPU 13 via a pull-up resistor 64, and is configured to operate by inputting an active signal output from the output port 65. Yes.
[0033]
In other words, the active signal is configured to output “H” when the watchdog circuit 21 monitors the CPU 13, and the watch is activated by turning on the first digita 61. “L” which is a monitoring permission signal can be supplied to the INH terminal 51 of the dock IC 22. Further, when the monitoring by the watchdog circuit 21 is stopped, the active signal is set to “L” to turn off the first digita 61, thereby providing an inhibition signal to the INH terminal 51 of the watchdog IC 22. H ″ can be supplied.
[0034]
A hold circuit 71 is connected to the base of the second digitra 62. The hold circuit 71 includes a one-shot IC 72, and battery power is supplied between the VCC terminal 73 and the GND 74 of the one-shot IC 72. A capacitor 77 is connected between the Cx terminal 75 and the Rx terminal 76 of the one-shot IC 72, and a resistor 78 is connected between the Rx terminal 76 and the power source. The pulse width output from the O terminal 79 to the base of the second digitra 62 can be determined by the time constants of the resistor 78 and the capacitor 77.
[0035]
The output of the OR logic 82 is connected to the input trigger terminal 81 of the one-shot IC 72, and one input of the OR logic 82 is grounded via a pull-down resistor 83. The other input is connected to the communication circuit 84. Every time an input edge is received from the communication circuit 84, the input has an "H" having a pulse width determined by the time constant of the resistor 78 and the capacitor 77. An output hold signal is output to the second digitra 62.
[0036]
Here, the pulse width of the hold signal is set to be sufficiently longer than the pulse interval sent from the communication circuit 84 during normal communication, and while the communication circuit 84 is performing communication, The values of the resistor 78 and the capacitor 77 are set so that the hold signal is output as a continuous waveform without interruption.
[0037]
That is, the hold circuit 71 is configured to output an “H” hold signal while the communication circuit 84 is performing communication, and turns on the second digita 62. Thus, the monitoring dock signal “L” can be supplied to the INH terminal 51 of the watchdog IC 22. Further, when communication is not performed in the communication circuit 84, an “L” output indicating that the hold signal is stopped is output, and the second digita 62 is turned off, whereby the INH terminal of the watchdog IC 22 is operated. 51 is configured to be able to supply “H” as a prohibition signal.
[0038]
The CLR terminal 85 of the one-shot IC 72 is also connected between the RESET output terminal 41 of the watchdog IC 22 and the reset terminal 43 of the CPU 13.
[0039]
The communication circuit 84 includes a communication IC 91 that controls communication with another on-vehicle device 12. The CANH terminal 92 and the CANL terminal 93 of the communication IC 91 are connected to a vehicle meter such as a speed meter via the in-vehicle LAN 11. It is connected to other vehicle mounting devices 12 such as a unit, an electric curtain unit, a wiper unit provided on the back door. The battery power is supplied between the VCC terminal 94 and the GND terminal 95 of the communication IC 91 via a capacitor 96, and transmission data transmitted to the in-vehicle LAN 11 is transmitted from the output port 97 of the CPU 13 via the transmission line to the TXD. It is configured to be input from a terminal 98. Further, the reception data received from the in-vehicle LAN 11 is configured to be input from the input port 101 of the CPU 13 through the reception line from the RDX terminal 99. By inputting the reception data from the input port 101, The sleep mode CPU 13 is configured to shift to the wake-up mode. As a result, the vehicle mounting device 1 can grasp the states of the ignition switch 105 and the door switch 106 that can be detected by the other vehicle mounting device 12.
[0040]
The RDX terminal 99 from which such received data is output is connected to the input of the OR logic 82 of the one-shot IC 72 in the hold circuit 71, and the hold circuit 71 is connected to the other vehicle-mounted device 12. It is configured to be able to grasp the communication state.
[0041]
The vehicle-mounted device 1 is provided with first and second closure relay drive circuits 111 and 112 (see FIG. 2), and both closure relay drive circuits 111 and 112 have bias resistors 113 and 113, respectively. 114, 114, NPN transistors 115 and 115, and diodes 116 and 116 on the output side. The bases of the transistors 115 and 115 are respectively connected to the output ports 117 and 118 of the CPU 13, and the emitters are grounded. The collectors of the transistors 115 and 115 are connected to one end of a coil of the first or second relay 121 or 122, and the other end of each coil is connected to a 12V power source.
[0042]
A 12V power source is connected to the first contacts 123 and 124 of the relays 121 and 122, and the second contacts 125 and 126 are grounded. The switching terminals 127 and 128 of the relays 121 and 122 are connected to the terminals of the closure motor 129, and the transistors 115 and 115 are turned on and off by the output from the CPU 13 to operate the relays 121 and 122. Thus, the closure motor 129 can be rotated forward and backward and stopped to operate the closure.
[0043]
The input ports 141 to 143 of the CPU 13 are provided with half-lock detection switch 144, full-lock detection switch 145, and initial position detection switch 146 provided in the closure, resistors 147,. 148,...
[0044]
Next, an outline of the operation of this closure will be described.
[0045]
When closing the door from the open state of the door, if the door is moved manually or automatically until the door lock device (not shown) immediately before full closing is in a half-locked state, the half-lock detection switch 144 The half-lock state is detected, and the CPU 13 outputs it. One of the relays 121 is actuated to rotate the closure motor 129 in the normal direction, and the door is closed from the half-lock position to the fully closed position (the door lock device is fully locked). Device.
[0046]
When the full lock state is detected by the full lock detection switch 145, the CPU 13 outputs, stops the operation of one relay 121, stops the closure motor 129, and then operates the other relay 122 to reverse the closure motor 129. Return to the initial position before closing. The initial position detection switch 146 detects that the closure has returned to the initial position, and the closure motor 129 is stopped.
[0047]
Since this closure operates when the door is closed, it only needs to be operable when the door is in the open state, and it is necessary to cope with the door opening and closing even when the engine is stopped. It can be operated even when 105 is off, and is controlled to be operable when the door switch 106 is turned on and the door is opened.
[0048]
Therefore, the CPU 13 can receive an ON signal of the door switch 106 from the communication signal from the RDX terminal 99 of the communication IC 91 in the communication circuit 84, and can operate when the door switch 106 is in the on state, that is, the door is in the open state. When the CPU 13 is in the sleep mode, the wake-up mode is set.
[0049]
Further, the output ports 151 and 152 of the CPU 13 include first and second sunroof relay drive circuits 157 and 158 comprising resistors 153, 153, 154, and 154, NPN transistors 155 and 155, and diodes 156 and 156, and A sunroof motor 163 is connected to the first or second sunroof relays 161 and 162.
[0050]
A 12V power source is connected to the first contacts (A) and (B) of the sunroof relays 161 and 162, and the second contacts (C) and (D) are grounded.
[0051]
The switching terminals (e) and (f) of the sunroof relays 161 and 162 are connected to the terminals of the sunroof motor 163, and the transistors 155 and 155 are turned on and off by the output from the CPU 13, respectively. The sunroof relays 161 and 162 are operated, and by operating the sunroof relays 161 and 162, the sunroof motor 163 is rotated forward and backward to stop and the sunroof can be opened and closed.
[0052]
The input port of the CPU 13 includes a sunroof slide open switch (le), a sunroof slide close switch (e), a sunroof tilt up switch (wa), and a sunroof tilt provided for operating the sunroof. A down switch (f) is input via resistors (y),... Pull-up resistors (t),.
[0053]
Next, an outline of the operation of this sunroof will be described.
[0054]
This sunroof is operated by the occupant turning on / off the switches (le) to (f). When the sunroof is in the closed state, when the sunroof slide open switch (le) is turned on, the CPU 13 outputs and operates one sunroof relay 161 to rotate the sunroof motor 163 in the normal direction.
[0055]
At this time, while the close switch (L) is on, the motor 163 continues normal rotation, the sunroof continues to move open, and when the open switch (L) is turned off, the motor is in that position. 163 stops and the sunroof stops. And when it moves to the fully open position, the fully open position is detected by a sensor (not shown), and the sunroof motor 163 is stopped even when the open switch (LE) is turned on, and the sunroof is stopped at the fully open position. The
[0056]
Further, when the sunroof is in the open state, when the sunroof slide close switch (e) is turned on, the CPU 13 outputs, and the other sunroof relay 162 is operated to reverse the sunroof motor 163.
[0057]
At this time, the motor 163 continues to reverse while the close switch (e) is on, the sunroof continues to move closed, and when the close switch (e) is turned off, the motor 163 stops at that position. The sunroof stops.
[0058]
Then, when it moves to the fully closed position, the fully closed position is detected by a sensor (not shown), and the sunroof motor 163 is stopped even if the close switch (e) is turned on, and the sunroof is fully closed. Stopped at position.
[0059]
Further, when the sunroof is in the closed state, when the sunroof tilt up switch (W) is turned on, the CPU 13 outputs, and the other sunroof relay 162 is operated to reverse the sunroof motor 163.
[0060]
At this time, the sunroof is slightly advanced from the fully closed position, the sunroof guide device (not shown) raises the rear part of the sunroof around the front part of the sunroof, and a so-called tilt-up is created between the rear part of the sunroof and the roof. When the state reaches a predetermined position, the sunroof motor 163 is stopped and the sunroof is held in the tilt-up state.
[0061]
When the sunroof is in the tilt-up state, when the sunroof tilt-down switch (f) is turned on, the CPU 13 outputs and operates one sunroof relay 161 to slightly rotate the sunroof motor 163 forward.
[0062]
At this time, the sunroof is slightly retracted from the slightly advanced position where the tilt-up operation is performed, and a so-called tilt-down operation is performed in which the rear end portion of the sunroof is lowered about the front portion of the sunroof by a sunroof guide device (not shown). The sunroof motor 136 is stopped at the fully closed position, and the sunroof is fully closed.
[0063]
Since the sunroof is controlled so as to be operated when the ignition switch 105 is on, the CPU 13 sends an on signal of the ignition switch 105 from the RDX terminal 99 of the communication IC 91 in the communication circuit 84. In response to the communication signal, the ignition switch 105 is controlled so as not to operate unless it is in the ON state. When the CPU 13 is in the sleep mode, the wake-up mode is set.
[0064]
Further, the vehicle-mounted device 1 is provided with a small lamp driving circuit a and a head wrap driving circuit b. The wrap driving circuits a and b include bias resistors a1, b1, a2 and b2, and NPN transistors. c and c and output side diodes d and d.
[0065]
The bases of the transistors c and c are respectively connected to the output ports e and f of the CPU 13, and the emitters are grounded.
[0066]
The collectors of the transistors c and c are connected to one end of a coil of a small lamp relay g and a head lamp relay h, and the other end of each coil is connected to a 12V power source.
[0067]
A 12V power source is connected to the first contacts g1 and h1 of the relays g and h, and the second contacts g2 and h2 are grounded.
[0068]
The switching terminals g3 and h3 of the relays g and h are connected to the terminals of the small lamp i and the headlamp j, respectively, and the transistors c and c are turned on and off by the output from the CPU 13 to switch the relays g. , H are activated, and the small lamp i and the head lamp j are turned on and off.
[0069]
The switching terminals g3 and h3 of the relays g and h connected to the small lamp i and the headlamp j are connected to the base of the third digitra 63 via diodes 131 and 131 (see FIG. 1), while any one of the switching terminals g3 and h3 is energized, that is, while the small lamp i and / or the headlamp j as the vehicle device is operating, the third digitra 63 is turned on, “L”, which is a monitoring permission signal, can be supplied to the INH terminal 51 of the watchdog IC 22.
[0070]
Further, when all the switching terminals g3 and h3 are de-energized, that is, when both the small lamp i and the headlamp j as the vehicle device are not lit, the third digitra 63 is turned off, and the watch dock IC 22 is operated. The INH terminal 51 can be supplied with “H”, which is a prohibition signal.
[0071]
In this way, the collectors of the respective digital tras 61 to 63 are connected and input to the INH terminal 51 of the watchdog IC 22 to constitute an OR circuit. The hold signal from the hold circuit 71, In a state where at least one of the active signal from the CPU 13 and the signals from the switching terminals g3 and h3 of the relays g and h is input, the INH terminal 51 of the watchdog IC 22 in the watchdog circuit 21 is input. , “L” indicating the monitoring permission signal is input.
[0072]
The input ports k and l of the CPU 13 are connected to the small lamp on position m of the lamp switch q provided for turning on and off the small lamp i and the head lamp j, and the head lamp on position n has resistances o, o, input via pull-up resistors p and p.
[0073]
Next, lighting and extinguishing of the small lamp i and the head lamp j will be described.
[0074]
When the occupant operates the lamp switch q to move to the small lamp on position m and the head lamp on position n, and the on and off operations are performed, the small lamp i and the head lamp j are turned on and off.
[0075]
Note that r is an off position.
[0076]
When the small lamp on position m is reached, the CPU 13 outputs and activates the small lamp relay g to light the small lamp i. When the head lamp is in the n position n, the CPU 13 outputs and operates the small lamp relay h to turn on the head lamp j. At this time, the small lamp i is also lit.
[0077]
In this state, the head lamp j is turned off when the head lamp is turned on from the position n, only the small lamp i is turned on, and the small lamp i is turned off when the head lamp is moved from the small lamp on position m.
[0078]
In addition, although the said closure showed what the operation control control, wakeup mode, and sleep mode were controlled by the CPU13 by the door switch-on signal input by the communication signal to CPU13, not only this but a closure, Like the small lamp i and the headlamp j, a vehicle-mounted device that is controlled independently of other signals that are not used for control may be input to the CPU 13 through communication.
[0079]
In this case, the control for switching the CPU 13 from the sleep mode to the wake-up mode is performed by the ON signal of the half lock detection switch 144 when the half lock state is detected by the half lock detection switch 144 of the closure. Is controlled to be operable.
[0080]
Further, after the initial position detection switch 146 detects the initial position and the closure motor 129 stops, control is performed so that the CPU 129 is switched from the wake-up mode to the sleep mode.
[0081]
Then, like the small lamp i and the headlamp j, while one of the relays of the closure is energized by one of the switching terminals 127 and the other switching terminal 128 and the closure motor 129 is operating, The third digitra 63 is turned on, the switching terminals 127 on one side and the switching terminal 128 on the other side are deenergized. When the closure motor 129 is not in operation, the third digita 63 is turned off. To.
[0082]
Both the small lamp i and the headlamp j are controlled so that they can be turned on and off regardless of whether the ignition switch 105 is on or not, and regardless of whether the door switch 106 is on. Control target that does not add (add to) the state of the door switch 106 to the control condition, that is, independently of other signals that are input to the CPU 13 through communication, such as small lamp i and head lamp j, are not used for control. In the vehicle-mounted device being controlled, the signal for setting the CPU 13 in the sleep mode to the wake-up mode is set by the on signal of the lamp switch q entering the small lamp position m, and the CPU 13 in the wake-up mode is set in the sleep mode. Signal is small lamp position The m performed by the off signal of the lamp switch q has been dropped.
[0083]
In the present embodiment according to the above configuration, when communicating with another on-vehicle device 12 via the in-vehicle LAN 11, the communication state is detected from the communication signal from the RDX terminal 99 of the communication IC 91 in the communication circuit 84. . From the hold circuit 71 that detects this, a hold signal is continuously output from the O terminal 79 of the one-shot IC 72 for a predetermined time, and is input to the second digital trait 62 constituting the OR circuit. Then, the OR circuit comprising the second digita 62 sends the monitoring permission signal to the watch dock circuit at least while the holding signal is input, that is, regardless of the presence or absence of the active signal from the output port 65 of the CPU 13. To 21.
[0084]
For this reason, when the CPU 13 is surely in the wake-up mode, an unexpected abnormal situation such as malfunction due to external noise or bug occurs, and the active signal from the output port 65 of the CPU 13 is stopped. Even if it exists, monitoring of CPU13 by the watchdog circuit 21 can be continued reliably.
[0085]
Thereby, although the CPU 13 is in the wake-up mode, the active signal is stopped and the monitoring function of the CPU 13 by the watchdog circuit 21 may be stopped. Further improvement can be achieved. In addition, by reliably monitoring the CPU 13 during communication, it is possible to reliably prevent adverse effects on other vehicle-mounted devices 12 via the in-vehicle LAN 11.
[0086]
Further, when the CPU 13 is not used, dark current can be reduced as compared with a case where the operating speed is lowered by dropping the clock of the CPU 13. Thereby, power consumption can be suppressed.
[0087]
The vehicle mounting apparatus 1 includes a small lamp i and a head lamp j as a vehicle apparatus that is controlled and operated independently by the control means such as the CPU 13. The small lamp i, the head lamp j is controlled by the CPU 13. For this reason, while outputting a signal for operating either or both of the small lamp i and the head lamp j, this signal is input by the third digita 63 constituting the OR circuit. . Then, the OR circuit provided with the third digitra 63 is active during the input of a signal for operating at least one of the small lamp i and the head lamp j, or both, that is, from the output port 65 of the CPU 13. Regardless of the presence or absence of a signal or a hold signal from the hold circuit 71, the monitor permission signal is output to the watch dock circuit 21.
[0088]
For this reason, when the CPU 13 reliably operates in the wake-up mode, either the small lamp i or the head lamp j, or both of them, an unexpected abnormal situation occurs and the active signal from the CPU 13 is stopped. In addition, the monitoring of the CPU 13 by the watchdog circuit 21 can be reliably continued. Therefore, the reliability can be further improved.
[0089]
In addition, a signal input to the CPU 13 by communication is controlled independently of the others that are not used for control, such as control of the small lamp i and the headlamp j as the vehicle mounted device, that is, with other vehicle mounted devices 12 The monitorability of the control means such as the CPU 13 during the single operation of the vehicle-mounted device that does not require communication can be improved, and the reliability can be further improved.
[0090]
【The invention's effect】
As described above, in the watchdog monitoring apparatus according to claim 1 of the present invention, some unexpected abnormal situation occurs during the communication with another on-vehicle apparatus in which the control means such as the CPU is in the wake-up mode. Thus, even when the active signal output from the control unit is stopped, the monitoring of the control unit by the watchdog circuit can be reliably continued.
[0091]
Thereby, although the control means is in the wake-up mode, the active signal is stopped and the monitoring function of the control means by the watchdog circuit may be stopped. Can be further improved. In addition, by reliably monitoring the control means during communication, it is possible to reliably prevent adverse effects on other vehicle-mounted devices via the network.
[0092]
Further, when the control means is not used, the dark current can be reduced as compared with the case where the operating speed of the control means is reduced. Thereby, power consumption can be suppressed.
[0093]
Further, in the watchdog monitoring device according to claim 2, the control means includes a vehicle mounting device that is controlled and operated independently of the others, and the vehicle device can be controlled by the control means. it can.
[0094]
While the signal for operating the vehicle device is output, this signal is input by the OR circuit, and at least the signal for operating the vehicle device is input to the OR circuit. In other words, regardless of whether there is an active signal from the control means or a hold signal from the hold circuit, the monitor permission signal is output to the watch dock circuit.
[0095]
Therefore, even when an unexpected abnormal situation occurs and the active signal from the control means is stopped when the vehicle device in which the control means such as the CPU is reliably in the wake-up mode is operated, the watch Monitoring of the control means by the dock circuit can be continued. Therefore, the reliability can be further improved.
[0096]
In addition, the monitorability of the control means such as the CPU during the single operation of the vehicle-mounted device that is controlled independently of the other that does not require communication with other vehicle-mounted devices can be improved, and the reliability can be further increased. Improvements can be made.
[Brief description of the drawings]
FIG. 1 is a circuit diagram showing an embodiment of the present invention.
FIG. 2 is a circuit diagram following FIG. 1;
[Explanation of symbols]
1 Vehicle-mounted device
11 Car LAN
13 CPU
21 Watchdog circuit
71 Hold circuit
84 Communication circuit
129 closure motor

Claims (2)

Control means such as a CPU whose mode is changed between a wake-up mode for performing normal operation and a sleep mode for restricting operation to a vehicle-mounted device connected via a network, and a watchdog for monitoring the operation of the control means A circuit and a communication circuit for exchanging communication signals with other devices with the control means,
A reset signal for resetting the control means when the watchdog circuit detects an abnormality in the periodic signal inputted from the control means in a state where the monitoring permission signal based on the active signal outputted from the control means is inputted. On the other hand, while the input of the monitoring permission signal is stopped based on the stop of the active signal, the watch prohibiting the output of the reset signal to the control means regardless of the input state of the periodic signal In the dock monitoring device,
A hold circuit that continuously outputs a hold signal for at least a predetermined time when a communication state is detected from the communication signal;
The holding signal output from the hold circuit and the active signal from the control means are input, and the monitoring permission signal is output to the watch dock circuit with at least one of the holding signal or the active signal being input. OR circuit to
A watchdog monitoring device comprising: While connecting the control means and the vehicle device controlled by the control means,
The OR circuit inputs a signal for operating the vehicle device in addition to the holding signal and the active signal, and outputs the monitoring permission signal in a state where at least one of these signals is input. 2. The watchdog monitoring device according to claim 1, wherein the watchdog monitoring device outputs to a watchdog circuit.

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