JP2009202822A - Control device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a control device capable of reducing the power consumption. <P>SOLUTION: A power supply control circuit 1 includes a CAN-I/F circuit 2 in which a CAN communication signal is input from an external apparatus, a time-counting circuit 3 for counting the re-starting time of a CPU 6, and a drive control circuit 4 for controlling the drive of a power supply IC 7. The CAN-I/F circuit 2 inputs a wake-up detection signal in the drive control circuit 4 when the CAN communication signal is input from the external apparatus, and inputs the CAN communication signal in the started CPU 6. The time-counting circuit 3 counts the wake-up time designated by the CPU 6, and inputs the power supply-ON signal in the drive control circuit 4 when the wake-up time is elapsed, and inputs the re-starting signal in the started CPU 6. The drive control circuit 4 inputs the starting signal when the wake-up detection signal is input from the CAN-I/F circuit 2, or when the power supply ON signal is input from the time-counting circuit 3, and the drive stop signal when the power supply OFF signal is input from the CPU 6 in the power supply IC 7, respectively. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a control device for a vehicle, and more particularly to a control device that can further reduce power consumption during non-operation.

In a control device such as an ECU (electronic control unit), when an event to be processed does not occur, the control device shifts to a sleep mode to reduce power consumption. For example, the microcomputer described in Patent Document 1 below performs a process of serially transmitting transmission data of a predetermined bit from an internal interrupt generation circuit to a watchdog timer every time a predetermined time elapses after transmission data transmission is completed. repeat. During the sleep mode, an internal interrupt occurs after transmission data is transmitted, and the microcomputer wakes up. By increasing the number of bits of transmission data that the internal interrupt generation circuit transmits to the watchdog timer in the sleep mode, the internal interrupt generation interval can be extended and the power consumption of the microcomputer can be reduced.
Japanese Patent Laid-Open No. 10-39960

  However, the microcomputer described in Patent Document 1 is supplied with power while the power supply capability of the in-vehicle battery is maintained. If a high-speed, large-capacity CPU is used, much power is supplied even in the sleep mode. Therefore, there is a demand for further reduction in the power consumption of the microcomputer when it is not in operation. In particular, in vehicles that tend to be equipped with a large number of control units such as CPUs, there is a strong demand for reduction in power consumption because of the limited battery capacity.

  An object of the present invention is to provide a control device such as an ECU that can reduce power consumption in view of the above points.

In order to achieve such an object, the control device of the present invention controls a first power source that supplies power to the control unit during operation of the control unit, and power supply from the first power source to the control unit. A control apparatus comprising: a power supply control means; and a second power supply that supplies power to the power supply control means separately from the first power supply, wherein the power supply control means operates the controller. A timer circuit for measuring the restart time after completion, and when the restart time is measured by the timer circuit, power is supplied from the first power source to the control unit, and the control unit has its own operation abnormality. It is characterized by making it determine.
Further, according to the present invention, the power supply control unit includes an external input receiving unit that receives a signal input from the outside, and receives the signal input from the outside by the external input receiving unit, and the control unit from the first power source Power is supplied to

  According to the present invention, power supply is performed by the power supply circuit every time the restart time is measured by the timing circuit after the operation of the control unit is completed, and the power supply to the control unit is shut off when the control unit is not operating. As a result, the amount of power consumed by the control device can be reduced.

Hereinafter, the best mode of the present invention will be described with reference to the drawings.
FIG. 1 is a block diagram showing an outline of the configuration of the control device 10 of the present embodiment. In the present embodiment, a vehicle control device (hereinafter referred to as an ECU) will be described as an example.

  The control device 10 is for controlling the operation of the vehicle electrical component, and the power supply control circuit 1 controls the power supply from the power supply IC (power supply circuit) 7 to the control unit including the CPU 6. The CPU 6 is connected to other circuits not shown. The power supply control circuit 1 controls driving of a CAN / I / F circuit 2 to which a CAN communication signal is input from an external device such as an ignition switch, a clock circuit 3 for measuring a restart time of the CPU 6, and a power supply IC 7. And a drive control circuit 4. The power supply IC 7 supplies power supplied from the in-vehicle battery to the CPU 6 under the control of the power supply control circuit 1.

  The CAN / I / F circuit 2 includes a CAN transceiver having a function of outputting a wakeup detection signal. The wakeup detection signal is input to the input terminal of the drive control circuit 4, and the CAN communication signal is input to the CAN terminal of the CPU 6. Respectively. The CAN / I / F circuit 2 is connected to an external device such as an ignition switch through a communication line. When a CAN communication signal is input from the external device, the CAN communication signal is input to the CPU 6 to be internally allocated. Generate. When the power supply from the power supply IC 7 is cut off and the drive of the CPU 6 is stopped, a wakeup detection signal is input to the power supply control circuit 4 and a CAN communication signal is input to the activated CPU 6. Generate an internal interrupt.

  The timer circuit 3 is composed of an RTC (Real time clock), and is connected to an input terminal of the drive control circuit 4 and an I / O terminal of the CPU 6. The time measuring circuit 3 measures the wake-up time according to an instruction from the CPU 6, and when the wake-up time elapses, inputs a power-on signal to the drive control circuit 4, and inputs a restart time signal to the activated CPU 6 to generate an internal interrupt. generate.

  The drive control circuit 4 is composed of an OR circuit having three input terminals and one output terminal, and each of the input terminals is a CAN / I / F circuit 2, a clock circuit 3, and an I / O of the CPU 6. The output terminal is connected to the power supply IC 7. The drive control circuit 4 is activated by the power supply IC 7 when no power-off signal is input from the CPU 6, a wake-up detection signal is input from the CAN / I / F circuit 2, or a power-on signal is input from the timing circuit 3. Output a signal. The CAN / I / F circuit 2, the timing circuit 3, and the drive control circuit 4 are driven by receiving power from the constant voltage power supply 5. The constant voltage power supply 5 distributes the power supplied from the in-vehicle battery to the power supply control circuit 1. Therefore, even if the output of the power supply IC 7 is interrupted in the sleep mode, the power supply to the power supply control circuit 1 is performed.

The operation of the control device 10 configured as described above will be described.
First, the system termination process performed by the CPU 6 when driving is stopped will be described with reference to the flowchart of FIG. In this process, the CPU 6 determines whether or not it is the end of the operation, that is, each process necessary for controlling the in-vehicle device being executed ends, or a predetermined time CAN / I / F circuit 2 from the end. It is determined whether or not a predetermined operation end condition such as no CAN communication signal input is satisfied (step S1). If this determination is “YES”, the CPU 6 determines whether or not saving of data necessary for restarting to the storage unit 8 has been completed (step S2). When the data saving is completed and the determination in step S2 is “YES”, the CPU 6 sets a wake-up time in the timing circuit 3 (step S3). That is, a control signal instructing to output a power-on signal after the wake-up time has elapsed is input to the timer circuit 3. The time measuring circuit 3 starts measuring the wake-up time after the input of this control signal or at the time measured by the input control signal.

  Next, the CPU 6 inputs a power-off signal (logical value = 0) to the drive control circuit 4 (step S4), and ends the process. The drive control circuit 4 to which the power-off signal is input inputs a drive stop signal (logical value = 0) to the power supply IC 7 and stops the power supply to the CPU 6 by the power supply IC 7. In this case, it is assumed that logic value = 0 is input to the other two inputs of the drive control circuit 4. As a result, the operation of the CPU 6 stops and the power consumption of the CPU 6 becomes “0”. Even when the operation of the CPU 6 is stopped, power supply from the constant voltage power supply 5 is continued to each circuit of the power supply control circuit 1, the CAN communication signal input acceptance by the CAN / I / F circuit 2, and timing Time is measured by the circuit 3.

  Next, the operation of the power supply control circuit 1 that activates the CPU 6 that has stopped operating as described above will be described. When the time measured by the time measuring circuit 3 reaches the wake-up time, the time measuring circuit 3 inputs a power-on signal (logical value = 1) to the drive control circuit 4. The drive control circuit 4 to which the power-on signal is input inputs a start signal (logical value = 1) to the power supply IC 7 and starts the power supply IC 7. The activated power supply IC 7 supplies power to the CPU 6, and the CPU 6 is activated. The activated CPU 6 receives a restart signal from the timing circuit 3 and performs a predetermined process such as determining an abnormality in the configuration circuit of the CPU 6 or the ECU or an external device, or after the predetermined process. When the operation termination condition is satisfied, the above-described system termination process is performed again.

  When a CAN communication signal is input from an external device, the CAN • I / F circuit 2 inputs a wakeup detection signal (logical value = 1) to the drive control circuit 4. The drive control circuit 4 to which the wakeup detection signal is input activates the power supply IC 7 and supplies power to the CPU 6. The CPU 6 activated upon receiving power supply receives a CAN communication signal from the CAN / I / F circuit 2 and performs necessary processing such as control of the in-vehicle device.

  According to the present embodiment, the driving of the power supply IC 7 that supplies power to the CPU 6 stops when the operation of the CPU 6 ends, the power supply to the CPU 6 is cut off, and the power consumption of the CPU 6 becomes “0”. Power consumption can be reduced. Moreover, since the power consumption of the clock circuit 3 including the CAN / I / F circuit 2 and the RTC used for restarting the CPU 6 is much smaller than the power consumption of the CPU 6 in the sleep mode, Power consumption can also be reduced.

  Further, according to the present embodiment, even if no CAN communication signal is input, the CPU 6 is restarted each time the wake-up time is measured by the timing circuit 3, and the functions of the constituent circuits of the CPU 6 and ECU and the functions of external devices Therefore, the probability of occurrence of an abnormality can be suppressed to a low level, and an abnormality can be detected at an early stage without overlooking the abnormality of the constituent circuits of the CPU 6 and ECU and external devices.

  Further, according to the present embodiment, when the CAN communication signal is input to the CAN / I / F circuit 2, the CPU 6 is started, so that the input of the CAN communication signal is confirmed at the time of restart due to the wake-up time. There is no need, and the wake-up time measured by the time measuring circuit 3 can be set to a time required for checking the functions of the constituent circuits of the CPU 6 and ECU and external devices. Accordingly, it is possible to reduce the power consumption by increasing the time interval between restarts performed after the wake-up time has elapsed, and suppressing the number of startups of the CPU 6 and the power supply IC 7 when no CAN communication signal is input.

  In the above embodiment, the timing circuit 3 may be used together with a timing circuit for acquiring time information such as date and time, or may be provided separately from this timing circuit. In the above embodiment, a case has been described in which a restart signal is input from the timing circuit 3 to the CPU 6 when the CPU 6 is restarted due to the wake-up time, but an internal interrupt is generated. When the CPU 6 is restarted, an internal interrupt may not be generated by using the power reset function of the CPU 6 by supplying power from the power IC 7. In other words, an abnormality diagnosis function that always works when the CPU 6 is restarted may be used to determine an abnormality in the constituent circuits of the CPU 6 or the ECU or an external device.

  In the above embodiment, the case where the power supply control circuit 1 is constantly supplied with power from the constant voltage power supply 5 has been described. However, the power supply control circuit 1 may be configured to receive power supply from the constant voltage power supply 5 only when driving of the power supply IC is stopped. . Moreover, although the case where the power supply control circuit 1 is provided in the ECU has been described in the above embodiment, it may be configured separately from the ECU. Further, the present invention can be applied not only to power supply to the control unit of the ECU that controls the operation of the vehicle electrical component, but also to power supply to the control unit provided in another control device such as a microcomputer.

It is a block diagram which shows the outline of a structure of the control apparatus of one Embodiment of this invention. It is a flowchart which shows the system completion | finish process which CPU performs at the time of a drive stop.

Explanation of symbols

1 Power Supply Control Circuit 2 CAN / I / F Circuit 3 Timekeeping Circuit 4 Drive Control Circuit 5 Constant Voltage Power Supply 6 CPU
7 Power supply IC (Power supply circuit)
10 ECU (control device)

Claims (2)

A first power source for supplying power to the control unit during operation of the control unit;
Power supply control means for controlling power supply from the first power source to the control unit;
A control device comprising a second power supply for supplying power to the power supply control means separately from the first power supply,
The power supply control means includes a timing circuit that times the restart time after the operation of the control unit is completed,
A control device characterized in that upon completion of the restart time measurement by the timer circuit, power is supplied from the first power source to the control unit, and the control unit is made to determine whether or not there is an abnormal operation. The power supply control means includes an external input receiving means for receiving a signal input from the outside,
The control apparatus according to claim 1, wherein the external input receiving unit receives a signal input from the outside and supplies power to the control unit from the first power supply.

Images