JP3861740B2 - Electronic control device - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a technique for measuring a time (soak time) after a power switch is turned off in an electronic control device that performs control by receiving power supplied from a battery when the power switch is turned on.
[0002]
[Prior art and problems to be solved by the invention]
2. Description of the Related Art Conventionally, for example, in an electronic control device that controls a vehicle engine, various electronic circuits centered on a microcomputer (hereinafter referred to as “microcomputer”) are provided as a control unit that performs various processes and operations for engine control. When the ignition switch as the power switch is turned on, power is supplied from the battery to operate.
[0003]
In recent years, in this type of electronic control device, there is a desire to know the time (hereinafter referred to as “soak time”) after the ignition switch is turned off and no substantial operating power is supplied to the electronic control device. There is.
That is, for example, heat management control is performed to switch control at engine startup using soak time. This heat management control is to start the engine after warming the engine cooling water, thereby reducing fuel consumption when starting the engine, thereby improving fuel efficiency and complying with exhaust gas regulations. It is. In this case, it is necessary to measure the soak time in order to predict a decrease in the water temperature after the ignition switch is turned off.
[0005]
Therefore, as a method for measuring such a soak time, it is considered to incorporate a semiconductor integrated circuit (IC) having a time counter in an electronic control unit and calculate the soak time from the count value.
However, there is a problem that the demand for the measurement time and the measurement accuracy of the soak time varies depending on the usage application of the soak time.
[0006]
  For example,UpIn the heat management control, since the cooling water is switched to warm water before the engine is started, it is necessary to measure, for example, a maximum of 7 days so that the user may start the operation at any time. An error of about 2 hours is allowed as accuracy.On the other hand, there is a usage in which an error of about several minutes is allowed as the measurement accuracy.
[0007]
  As described above, since the measurement of the soak time changes depending on the application, in order to satisfy this with a single IC, it is conceivable to develop an IC capable of measuring the maximum time. HoweverEven when measuring a long soak time, a certain level of measurement accuracy may be required.BecauseIn such casesThe number of counts inside the IC becomes excessive.
[0008]
In addition, it is conceivable to develop an IC according to each application, but in that case, several types of ICs are required, leading to an increase in cost.
The present invention has been made in view of these problems. In an electronic control device that receives power supplied from a battery when a power switch is turned on and performs control, the soak time is measured with measurement time and measurement accuracy according to the application. In addition, it is an object of the present invention to be able to realize this easily and at low cost.
[0009]
[Means for Solving the Problems]
  In view of the above problems, in the electronic control device according to claim 1, a host microcomputer that receives a main power supply voltage supplied from a battery and executes a predetermined control program when the power switch is turned on, and the host microcomputer Is connected via a communication line, operates by receiving the sub-power supply voltage supplied from the battery, and has a built-in counter that starts up-counting at a preset time interval according to a command from the host microcomputer IC is provided. The soak time during which the power switch is turned off can be measured by the cooperation between the host microcomputer and the timing IC. That is, while the power switch is off, the supply of the main power supply voltage necessary for the execution of the control program is substantially cut off, and the timing IC operates only with the sub power supply voltage. Power saving is achieved.Here, the “time interval” means a timing at which a counter composed of a plurality of bits switches up and counts the least significant bit (hereinafter referred to as “LSB”).
[0010]
  AndThe counter starts up-counting after the power switch is turned off, and after starting up-counting, every time a predetermined allowable time is measured based on the count number that can be counted by the counter and a set time interval. Cleared. The “allowable time” here refers to the time measured based on the number of counts that can be counted by the counter, and may be the same as the maximum time of the counter or may be shorter than this. There may be.
Further, the activation means temporarily activates the host microcomputer using the main power supply voltage from the battery without turning on the power switch every time the allowable time is measured by the counter. Then, the counting means provided on the host microcomputer side counts up and stores the number of times the host microcomputer has been activated by the activation means. The number of activations can be stored by always supplying a sub power supply voltage to a counting memory provided on the host microcomputer side, or by storing it in a nonvolatile memory.
When the host microcomputer is turned on again after the power switch is turned off, the soak time is determined based on the count number of the counting means at the time when the power switch is turned on, the allowable time count of the counter, and the count number indicated by the counter. Is calculated.
That is, in this case, the time obtained by multiplying the allowable time by the count number of the counting means and the time calculated from the count number indicated by the counter is the soak time.
According to such a configuration, long-time measurement can be performed in a state where the measurement accuracy of the timekeeping IC is maintained at a certain level or more depending on the use of the soak time. At that time, there is no increase in time-measurement IC. In addition, since the host microcomputer is only temporarily activated using the main power supply voltage, it does not consume much battery power. For this reason, the measurement of the soak time can be realized easily and at low cost in correspondence with the required values of all measurement accuracy and measurement time.
The electronic control device according to claim 2, further comprising:Based on the command signal output from the host microcomputer when the power switch is turned off or before the switch is turned off, the counter counts up at a selected time interval among a plurality of preset time intervals. Switch the above time interval setting toThe
[0011]
  According to such a configuration, the time interval of up-counting by the counter can be appropriately switched and changed by the determination on the host microcomputer side according to the usage application of the soak time. For example, the measurement time of the soak time is shorter than the heat management control described above, and high measurement accuracy is required.In such applications,A method such as shortening the time interval of up-counting can be taken. Alternatively, when a more accurate soak time measurement is required for another application, this can be realized by further shortening the time interval. In addition, since it is configured to switch the time interval (timing) of the upcount of the timekeeping IC, it is not necessary to change the hardware configuration such as the capacity of the counter.
[0012]
  For this reason, when high measurement accuracy is required for soak time measurement depending on the application, it can be handled by setting the up-count time interval to be short, and when long-time measurement is required. This can be dealt with by setting the up-count time interval to be longer. As a result, it is possible to adapt to multiple applications with a single IC (timer IC), and to realize soak time measurement with measurement time and measurement accuracy according to the application easily and at low cost. it can.
In order to meet the required values for various applications with a single IC as described above, the type of the time interval is set so that the requirements for the highest measurement accuracy among the assumed applications are satisfied. (In other words, it is desirable to design an IC based on the most demanding measurement accuracy).
More specifically, the output of the command signal from the host microcomputer can be as described in claim 3, for example. In other words, when a holding signal is input from the host microcomputer, the host microcomputer has holding means for supplying a main power supply voltage to the host microcomputer. The host microcomputer sends a holding signal to the holding means for a predetermined period after the power switch is turned off. The command signal is output while continuing its own operation by outputting.
That is, even if the power switch is turned off, the host microcomputer does not stop operating immediately, but receives the main power supply voltage supplied from the holding means by the holding signal output by itself, and continues to operate for a predetermined period. During this time, a command signal is output.
[0017]
  In addition, although what is applied to various uses can be considered as said electronic control apparatus, for example,Claim 4As described above, when the power switch is an ignition switch for a vehicle and the host microcomputer is for controlling the engine of the vehicle, it is possible to further reduce the power consumption when the ignition switch is off. Become important. For this reason, it has a great effect on the configuration of the electronic control device that measures the soak time by using a timing IC that operates by receiving the sub power supply voltage for power saving.
[0020]
DETAILED DESCRIPTION OF THE INVENTION
Preferred embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a block diagram showing an electrical configuration of the electronic control device of this embodiment.
As shown in the figure, an electronic control unit (hereinafter referred to as “ECU”) 1 controls an engine mounted on a vehicle, and is connected to a plus terminal of a battery 2 of the vehicle via a main relay 3. The main power supply terminal J1, the secondary power supply terminal J2 always connected to the positive terminal of the battery 2, and the IGSW connected to the positive terminal of the battery 2 via an ignition switch (hereinafter referred to as “IGSW”) 4 as a power switch. A terminal J3, a main relay drive terminal J4 connected to the plus terminal of the battery 2, and a main relay drive terminal J5 connected to the other end of the coil L of the main relay 3 grounded at one end.
[0021]
The ECU 1 includes a CPU, a RAM, a ROM, and the like, and performs a soak time after the IGSW 4 is turned off by serial communication between the host microcomputer 5 and a host microcomputer 5 that executes various control programs for controlling the engine. A soak timer IC 10 as a timekeeping IC for measurement and various analog values such as various sensor signals (not shown) and battery voltage (that is, the voltage of the battery 2) used for engine control are converted into digital values to the host microcomputer 5. The A / D converter 6 to be input and the battery voltage (hereinafter referred to as “VIG”) input from the IGSW terminal J3 via the IGSW 4 are converted into an IGSW signal having a voltage level that can be input by the host microcomputer 5. , The input circuit 7 for outputting to the host microcomputer 5 and the main power supply terminal J1 via the main relay 3 The main power supply voltage Vm for operating the host microcomputer 5 and the A / D converter 6 is generated and output from the input battery voltage (hereinafter referred to as “V + B”) and is always input from the sub power supply terminal J2. A power supply circuit 8 that generates and outputs a sub power supply voltage Vs for the standby RAM built in the host microcomputer 5 to always hold data from a battery voltage (hereinafter referred to as “VBAT”), and a predetermined condition And a main relay control circuit 20 for turning on the main relay 3 by short-circuiting between the main relay drive terminals J4 and J5 and causing a current to flow through the coil L of the main relay 3.
[0022]
The power supply circuit 8 outputs a reset signal to the host microcomputer 5 only for a predetermined time when the main power supply voltage Vm is considered stable after receiving the supply of V + B and starting to output the main power supply voltage Vm. It also has an on-reset function. The input circuit 7 is composed of electronic components that do not require a power source.
[0023]
Next, a schematic configuration of the soak timer IC 10 will be described with reference to FIG.
As shown in the figure, the soak timer IC 10 includes a serial I / O 11 for inputting / outputting signals to / from the host microcomputer 5, a timer unit 12 for measuring the soak time, and an external oscillation circuit 30. A reference clock generation unit 13 that divides or multiplies the generated oscillation clock (several MHz in this embodiment) and generates a reference clock used when the timer unit 12 counts up is provided.
[0024]
The timer unit 12 operates to divide or multiply the reference clock input from the reference clock generation unit 13 based on a command signal input from the host microcomputer 5 via the serial I / O 11 and switch to the count operation clock. A clock generation unit 14, a soak timer counter 15 comprising a 6-bit counter that is always counted up based on this operation clock, and an output in which a value as time information to be compared with the count value of the soak timer counter 15 is set A compare register (OCR) 16 is provided, and a comparator 17 that compares the count value of the soak timer counter 15 with the value set in the OCR 16 and outputs a main relay drive signal when the two values match.
[0025]
The soak timer IC 10 has a plurality of terminals, and a clock for synchronization is input from the host microcomputer 5 via the SCLK terminal and the Schmitt circuit 41 shown in the figure, and this clock is supplied to the clock via the SRXD terminal and the Schmitt circuit 42. Serial data such as a synchronized command signal is input. When these data are input, a reset signal is input from the host microcomputer 5 via the IORESB terminal and the Schmitt circuit 43 as preprocessing, and the serial I / O 11 is initialized. Then, time information input from the host microcomputer 5 via the serial I / O 11 is set in the OCR 16, and a setting code to be described later for measuring the soak time is set in the operation clock generator 14. On the other hand, transmission data such as the count value of the soak timer counter 15 is output from the soak timer IC 10 to the host microcomputer 5 via the serial I / O 11, the buffer 44 and the STXD terminal.
[0026]
On the other hand, the timer unit 12 can switch the measurement time and measurement accuracy of the soak time to a plurality of stages by switching the reference clock input from the reference clock generation unit 13 to the operation clock and up-counting based on this operation clock. It is like that. This switching is performed by dividing or multiplying the reference clock by the operation clock generation unit 14 based on the setting code included in the command signal from the host microcomputer 5 and generating the corresponding operation clock.
[0027]
In other words, the oscillation clock generated by the external oscillation circuit 30 is input to the reference clock generation unit 13 via the XIN terminal and is divided (in some cases, further multiplied) to be a reference clock having a frequency lower than that of the oscillation clock. Converted. When this reference clock is input to the timer unit 12, the operation clock generation unit 14 performs frequency division or multiplication processing based on the current setting code to switch the frequency of the operation clock, and the operation clock is converted to the soak timer. The data is sequentially output to the counter 15. In the soak timer counter 15, the least significant bit (LSB) is switched in synchronization with the operation clock, and the up counting is performed.
[0028]
When the set value of the OCR 16 matches the count value of the soak timer counter 15, the main relay drive signal is output from the comparator 17 to the main relay control circuit 20 via the flip-flop 18, the OR circuit 46, and the PI_OUT terminal. The
[0029]
When this main relay drive signal is output, the information and the count value of the soak timer counter 15 are transmitted to the host microcomputer 5, and in some cases, the host microcomputer 5 stops the count process in the timer unit 12. The stop command signal is input. This stop command signal is input to the reference clock generation unit 13 as an XSTOP signal via the serial I / O 11, and the reference clock generation unit 13 temporarily stops outputting the reference clock to the timer unit 12 in response to the XSTOP signal. To do. Then, after the soak timer counter 15 and the like are cleared, the output of the reference clock is started again by a command from the host microcomputer 5.
[0030]
The sub power supply voltage Vs is supplied to the soak timer IC 10 via the VOS5 terminal, and the GND terminal is grounded. The soak timer IC 10 includes a power-on reset circuit 19. When the sub power supply voltage Vs is supplied, a reset signal is output from the power-on reset circuit 19 to the timer unit 12 and the serial I / O 11. Initialization is performed. The reset signal is also input to the flip-flop 18 via the OR circuit 47, and the information in the flip-flop 18 is initialized by inputting the reset signal or the counter clear signal of the serial I / O11. Is done.
[0031]
Next, the process for switching the measurement time and measurement accuracy of the soak time will be described with reference to FIG.
In this embodiment, the measurement time and measurement accuracy of the soak time can be switched to a plurality of stages, and in the example of the figure, it can be switched to 5 stages by setting any of the setting codes “000” to “100”. It is configured. In this case, since the setting magnification (that is, the ratio of the operation clock frequency to the reference clock frequency) by the setting code “010” is 1 time, when the setting code is selected, the reference clock is set as the operation clock as it is. The LSB of the soak timer counter 15 is up-counted every 10 minutes. As described above, since the soak timer counter 15 of this embodiment is a 6-bit counter, the measurement can be performed for a maximum of 10 hours and 30 minutes.
[0032]
Similarly, for the setting codes “001” and “000”, the magnifications are 0.25 and 0.0625, respectively, an operation clock is generated by dividing the reference clock, and the maximum measurement time is 42 hours and 168 hours. Therefore, long-time measurement is possible. On the contrary, for the setting codes “011” and “100”, the magnifications are 375 and 1875, respectively, and an operation clock is generated by multiplying the reference clock, and the maximum measurement time is 1 minute 40 seconds and 20 seconds. Although only short-time measurement is possible, the LSB upcount timing is 1.6 seconds and 320 ms, respectively, and high-precision measurement is possible.
[0033]
Returning to FIG. 1, the main relay control circuit 20 includes an OR circuit 21 and a starting transistor (PNP transistor) 22 connected to the output destination. The emitter of the starting transistor 22 is connected to the main relay drive terminal J4, the collector is connected to the main relay drive terminal J5, and the base is connected to the OR circuit 21.
[0034]
Then, as described above, the main relay activation signal is output from the soak timer IC 10, the microcomputer holding signal is output from the host microcomputer 5, or VIG is supplied from the IGSW terminal J 3 and input to the OR circuit 21. Then, the transistor 22 is turned on, a current is passed through the coil L of the main relay 3, the main relay 3 is turned on, the main power supply voltage Vm is supplied to the host microcomputer 5, etc., and normal control processing by the engine ECU 1 is started. . Note that the microcomputer holding signal is a signal that is output to start the host microcomputer 5 until the electronic slot is closed, for example, even when the IGSW 4 is turned off. As shown in FIG. 2, the microcomputer holding signal is once inputted from the host microcomputer 5 to the soak timer IC 10 via the PI_IN terminal, and then outputted to the main relay control circuit 20 via the Schmitt circuit 45, the OR circuit 46 and the PI_OUT terminal. Is done. When the output of all these signals and the like is stopped, the main relay 3 is turned off and the supply of the main power supply voltage Vm to the host microcomputer 5 and the like is shut off.
[0035]
  Next, a specific method for measuring the soak time will be described with reference to FIGS. First, FIG. 4 shows the soak time measurement method of this embodiment.So-called perforated confirmation for detecting leaks in the EVP system (evaporator system) (hereinafter also referred to as “EVP leak check”)It is an example adapted to.EVP leak check is EVP In response to OBD (California emissions regulations), an electronic control device is activated during soak to detect EVP system leaks from the tank to the canister and surge tank. Is required.
In this example, the battery voltage V + B (that is, the main power supply voltage Vm) is temporarily supplied 5 hours after the IGSW 4 is turned off to start the host microcomputer 5, and the battery voltage V + B is cut off after the EVP leak check. The host microcomputer 5 is stopped. Therefore, here, the time (5 hours) until the host microcomputer 5 is activated during the soak is measured.
[0036]
First, since the host microcomputer 5 can operate by outputting the microcomputer holding signal immediately after the IGSW 4 is turned off as described above, the setting code corresponding to the soak time measured using this interval and its time information ( That is, the next host microcomputer 5 outputs a start time) and a count start command signal to the soak timer IC 10. Then, after finishing the processing such as closing the electronic slot, the microcomputer holding signal is stopped, the supply of the battery voltage V + B is cut off, and a so-called sleep state is entered.
[0037]
The setting code is set in the operation clock generation unit 14 of the timer unit 12, and the time information is set in the OCR 16. Then, the output of the XSTOP signal from the serial I / O 11 is stopped by the count start command signal, and the reference clock is output from the reference clock generation unit 13 to the operation clock generation unit 14 and converted to the operation clock. A counting process based on this is executed.
[0038]
In this example, “010” is set as the setting code, and the LSB is up-counted every 10 minutes. Therefore, the maximum measurement time is 10 hours and 30 minutes, and the measurement time of 5 hours falls within the allowable time measurement time of the soak timer IC 10. Therefore, the count processing in the soak timer IC 10 may be performed only once. When the count value of the soak timer counter 15 matches the set value of the OCR 16, a main relay drive signal is output and the host microcomputer 5 (that is, the engine ECU 1) is activated. Then, an EVP leak check is performed.
[0039]
In this case, if the measurement error of the soak timer IC 10 is 1%, the measurement error in the 5-hour measurement is about ± 3 minutes, and the reading error is about 10 minutes. In this case, the EVP leak check is completed in about 15 minutes, but the soak timer counter 15 may be left until the IGSW 4 is turned on, or may be cleared after the measurement for 5 hours.
[0040]
Next, FIG. 5 shows an example in which the soak time measurement method is applied to heat management control.
As shown in the figure, in this heat management control, five days are measured as the soak time, and the IGSW 4 is turned on when five days have passed. Although this measurement takes a relatively long time, “010” is set as a setting code in order to obtain a measurement accuracy of a certain level or more, and the host microcomputer 5 is activated every time 10 hours are measured by the soak timer IC 10, and a built-in standby. The number of activations is stored in the RAM, and when 5 days have elapsed, the battery voltage V + B is supplied to the host microcomputer 5 to operate the engine ECU 1. As described above, since the standby power supply voltage Vs is always supplied to the standby RAM, it is possible to continuously store the number of activations even when the host microcomputer 5 is stopped.
[0041]
First, since the host microcomputer 5 can operate by outputting the microcomputer holding signal immediately after the IGSW 4 is turned off as described above, the soak time measured using this interval after clearing the built-in standby RAM. Is output to the soak timer IC 10 in response to the setting code, its time information (that is, the next host microcomputer 5 startup time), and a count start command signal. Then, after finishing the processing such as closing the electronic slot, the microcomputer holding signal is stopped, the supply of the battery voltage V + B is cut off, and a so-called sleep state is entered.
[0042]
The setting code is set in the operation clock generation unit 14 of the timer unit 12, and the time information is set in the OCR 16. Then, the output of the XSTOP signal from the serial I / O 11 is stopped by the count start command signal, and the reference clock is output from the reference clock generation unit 13 to the operation clock generation unit 14 and converted to the operation clock. A counting process based on this is executed.
[0043]
In this example, since “010” is set as the setting code, the LSB is up-counted every 10 minutes. For this reason, the maximum measurement time is 10 hours and 30 minutes, and the measurement time of 5 days (120 hours) exceeds the maximum measurement time of the soak timer IC10. Therefore, the OCR 16 is set with a count value corresponding to 10 hours as an allowable timing time in the measurement accuracy, and when the count value of the soak timer counter 15 coincides with this, a main relay drive signal is output, and the host microcomputer 5 (In other words, the engine ECU 1) temporarily starts up, adds the number of startups and stores it in the standby RAM, and then shifts to the sleep state again. The soak timer counter 15 is cleared every time the host microcomputer 5 is started, and starts counting again when the sleep microcomputer 15 shifts to sleep again. Such an operation is repeated.
[0044]
When the IGSW 4 is turned on again, the count value of the soak timer counter 15 is transmitted to the host microcomputer 5. In the host microcomputer 5, the soak time is calculated based on the count value of the soak timer counter 15 when the IGSW 4 is turned on and the number of times the host microcomputer 5 has been started up to that point. That is, the time calculated from the count value of the soak timer counter 15 at the time when the IGSW 4 is turned on and the time obtained by multiplying the time measured by the soak timer counter (10 hours) by the number of times of activation of the host microcomputer 5 are added. Time is the soak time in this case.
[0045]
If the IC error as the measurement accuracy in this case is 1%, the measurement error in the measurement for 5 days (120 hours) is about ± 1 hour 12 minutes, and the reading error is 10 minutes.
Thus, in the case of heat management control, since the measurement takes a longer time than in the case of the EVP OBD described above, the allowable time is exceeded in the same soak timer IC 10, so the measurement by the soak timer counter 15 is constant. The measurement can be performed by repeating with time and counting up the number of repetitions by starting the host microcomputer 5. For this reason, long-time measurement is possible by the cooperation of the single soak timer IC 10 and the host microcomputer 5.
[0046]
As described above, according to the electronic control device 1 of the present embodiment, a plurality of preset upcounts are set based on the setting code included in the command signal output from the host microcomputer 5 when the IGSW 4 is turned off. An appropriate time interval is selectively switched among the time intervals. The host microcomputer 5 calculates the soak time based on the count value counted up by the soak timer counter 15.
[0047]
According to such a configuration, the time interval of up-counting by the single soak timer counter 15 can be appropriately switched and changed according to the determination on the host microcomputer 5 side according to the usage of the soak time such as EVP OBD and heat management control. Can do. For this reason, the single soak timer IC 10 can be applied to a plurality of applications, and the measurement of the soak time with the measurement time and the measurement accuracy according to the application can be realized easily and at low cost.
[0048]
Further, when the measurement time of the soak time exceeds the allowable time of the soak timer IC 10, the fixed time is measured by the soak timer IC 10, and this is measured by counting the number of times of measurement on the host microcomputer 5 side. Can do. For this reason, there is no increase in the soak timer IC 10 even in long-time measurement. Further, since the host microcomputer 5 is only temporarily activated using the sub power supply voltage, the power of the battery 2 is not consumed greatly. For this reason, the measurement of the soak time can be realized easily and at low cost corresponding to all measurement accuracy and measurement time.
[0049]
  In this embodiment, the host microcomputer 5 and the soak timer IC 10 correspond to switching means and starting means, and the host microcomputer 5 corresponds to counting means..
[0050]
As mentioned above, although the Example of this invention was described, it cannot be overemphasized that embodiment of this invention can take various forms, as long as it belongs to the technical scope of this invention, without being limited to the said Example at all. Nor.
For example, in each of the above-described embodiments, an example of the soak time measurement method has been described. However, the possible measurement methods are not limited to those described above, and can be appropriately changed according to the requirements for the measurement time and the measurement accuracy. Specifically, in the case of the above heat management control, if, for example, “000” is selected as the setting code as shown in FIG. 6 and the LSB up-count is set every 160 minutes, the soak timer IC 10 alone is set to 5 Daily soak time can be measured. However, in this case, it should be noted that the reading error is 2 hours and 40 minutes, which is larger than the above case.
[0051]
On the contrary, when the measurement time is short and high-precision measurement is performed, it is preferable to select “011” or “100” as the setting code.
In the above-described embodiment, the configuration in which the microcomputer holding signal is input to the OR circuit 21 of the main relay control circuit 20 after passing through the soak timer IC 10 has been described. However, the microcomputer holding signal does not pass through the soak timer IC 10. The configuration may be such that it is directly input to the OR circuit 21.
[Brief description of the drawings]
FIG. 1 is a block diagram illustrating a schematic configuration of an electronic control device according to an embodiment of the present invention.
FIG. 2 is a block diagram illustrating a schematic configuration of a semiconductor integrated circuit according to an embodiment.
FIG. 3 is an explanatory diagram illustrating a switching mode of soak time measurement according to the embodiment.
FIG. 4 is an explanatory diagram illustrating a specific example of soak time measurement processing according to the embodiment.
FIG. 5 is an explanatory diagram illustrating a specific example of soak time measurement processing according to the embodiment.
FIG. 6 is an explanatory diagram illustrating a specific example of soak time measurement processing according to the embodiment.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 ... Electronic controller, 2 ... Battery, 5 ... Host microcomputer,
3 ... Main relay, 8 ... Power supply circuit, 12 ... Timer part,
13: reference clock generation unit, 14: operation clock generation unit,
15 ... Soak timer counter, 16 ... OCR,
17 ... Comparator, 20 ... Main relay control circuit,
30 ... External oscillation circuit, 47 ... OR circuit,
10 ... Soak timer IC

Claims (4)

A host microcomputer that receives a main power supply voltage supplied from a battery and executes a predetermined control program when the power switch is on;
It is connected to the host microcomputer via a communication line, operates by receiving a sub power supply voltage supplied from the battery, and starts up-counting at a preset time interval according to a command from the host microcomputer. A timing IC with a built-in counter;
An electronic control unit capable of measuring a soak time after the power switch is turned off by the cooperation of the host microcomputer and the timing IC,
The counter starts the up-counting after the power switch is turned off, and after the up-counting starts, measures a predetermined allowable time based on the count number that can be counted by the counter and the time interval. Cleared every time
further,
Start means for temporarily starting the host microcomputer using the main power supply voltage from the battery without turning on the power switch every time the allowable time measurement is measured by the counter;
Counting means for counting up and storing the number of times the host microcomputer has been activated by the activation means;
With
When the host microcomputer is turned on again after the power switch is turned off, the host microcomputer is based on the count number of the counting means at the time when the power switch is turned on, the allowable timing time of the counter, and the count number indicated by the counter An electronic control device for calculating the soak time. The electronic control device according to claim 1, further comprising:
Based on a command signal output from the host microcomputer before or after the power switch is turned off, the counter counts up at a selected time interval among a plurality of preset time intervals. As described above, an electronic control device comprising switching means for switching the setting of the time interval. The electronic control device according to claim 2,
A holding means for supplying the main power supply voltage to the host microcomputer when a holding signal is input from the host microcomputer;
The host microcomputer outputs the command signal while continuing its operation by outputting the holding signal to the holding means for a predetermined period after the power switch is turned off.
An electronic control device. The electronic control device according to any one of claims 1 to 3,
The power switch is a vehicle ignition switch,
The host microcomputer is for controlling the engine of the vehicle;
An electronic control device .

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