JP2007320456A - On-vehicle electronic equipment control device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an on-vehicle electronic equipment control device capable of correctly returning to a control state before reset, even when a RAM storing control data of on-vehicle electronic equipment is reset due to instantaneous cut-off of power supply voltage etc. <P>SOLUTION: The control data indicating an operating state to be commanded with respect to the on-vehicle electronic equipment 40 is stored in a main control memory 12a of the RAM 12 for control, and the data stored in the main control memory 12a is stored as backup data in a fixation memory 20a for main return of a nonvolatile memory 20 and a backup memory 12b of the RAM 12. After a semi-reset process for resetting the main control memory 12a while protecting backup control data within the backup memory 12b is performed, operation of the on-vehicle electronic equipment 40 is returned by using the control data of the backup memory 12b. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a control device for an in-vehicle electronic device.

Japanese Patent Application No. 2002-347541

  In recent in-vehicle electronic device control devices, the stored contents can be rewritten in a state where a voltage supply exceeding a predetermined voltage threshold is received from the in-vehicle battery, and the stored contents are retained even if the voltage supply is cut off. There is one in which a nonvolatile memory such as an EEPROM and a control unit are connected (for example, Patent Document 1).

  The control unit of such a control device is composed of a well-known microcomputer having a CPU, ROM, RAM, and the like. The control program for controlling the on-vehicle electronic device stored in the ROM by the CPU uses a work memory of the RAM. By performing the above, the operation control of the in-vehicle electronic device is performed. However, in the case of a normal RAM, when an instantaneous interruption or the like occurs in a state where the battery voltage is lowered, a reset process is executed if the supplied voltage falls below a predetermined stored content holding voltage. The stored contents are cleared. In this case, even if the voltage is restored, the control data stored in the RAM is cleared, so that it is impossible to return the operation state of the in-vehicle electronic device to the state immediately before the instantaneous voltage interruption.

  Therefore, if the control data stored in the RAM is backed up in the non-volatile memory and the reset process of the RAM is executed due to a voltage drop, the value of the backup data is written in the non-volatile memory after the voltage is restored. Thus, there is already a technique for reproducing the operation control state of the in-vehicle electronic device before the RAM reset.

  For example, as a control device that controls lighting of a hazard lamp by operating a momentary-type operation switch (alternate switching between blinking operation state and extinguishing state) Each time is switched, the operation control command information of the hazard lamp is stored in the non-volatile memory, and at the time of return processing after the RAM reset, the operation control command information stored in the non-volatile memory is read into the RAM, There is something that reproduces the lighting control state of the hazard lamp.

  However, generally, in such a non-volatile memory, the write guarantee lower limit voltage is set at a voltage level higher than the storage content holding voltage of the RAM. Is prohibited. Rewriting to a non-volatile memory requires data to be transferred via a communication line, so it takes time to store the data. In a situation where a low-voltage state continues in an in-vehicle battery that is a power source, for example, voltage There is a possibility that the data cannot be stored reliably because the voltage falls momentarily below the write guarantee lower limit voltage due to a momentary interruption or the like, and there is a case where it cannot function as a RAM backup.

  Specifically, in the case of the control device that controls the lighting of the hazard lamp as described above, the control stored in the work memory of the RAM for operation control even when the switch operation is performed when the vehicle-mounted battery is at a low voltage. Data may not be properly backed up (stored) in the non-volatile memory, and data mismatch may occur between the RAM and the non-volatile memory. Under such circumstances, when the power supply voltage drops to a point where it falls below the stored content retention voltage of the RAM due to an instantaneous voltage interruption, etc., and a RAM reset is executed, after the restoration process, the lighting state of the hazard lamp is the state before the instantaneous voltage interruption May resume in a different state. For example, the hazard lamp blinking before the momentary voltage interruption may turn off due to the momentary voltage interruption, or vice versa. It becomes necessary.

  The present invention has been made in view of the above problems, and even when the RAM in which the control data of the in-vehicle electronic device is stored is reset due to an instantaneous interruption of the power supply voltage or the like, the control state before the reset is correctly restored. It is providing the vehicle-mounted electronic device control apparatus which can do.

Means for Solving the Problems and Effects of the Invention

In order to solve the above-described problems, an in-vehicle electronic device control device of the present invention is
The control data indicating the operation state to be commanded to the in-vehicle electronic device is updated in a form corresponding to the transition of the control state. Main control memory to store,
Device operation control means for controlling the operation of the in-vehicle electronic device based on the control data in the main control memory;
A main return fixed memory in which main return control data is written, which is formed in a non-volatile memory, and for returning the operation of the in-vehicle electronic device when the control data in the main control memory is erased by a RAM reset;
A backup memory provided separately from the main control memory in the RAM, in which backup control data obtained by backup copying the control data in the main control memory is written while being updated together with the main control memory;
When the power supply voltage of the RAM is monitored and the power supply voltage falls below a predetermined total reset voltage, the stored contents of the RAM including the main control memory are fully reset. RAM reset means for performing a semi-reset process for resetting the main control memory while protecting the backup control data in the backup memory when it is high and falls below a predetermined semi-reset voltage;
When the power supply voltage recovers from the all reset state, the control data for reset recovery is used to recover the operation of the in-vehicle electronic device. When the voltage recovers from the semi-reset state, the in-vehicle electronic device is recovered using the backup control data. Reset return means for returning the operation,
It is characterized by having.

  According to the present invention, a backup memory capable of holding the stored contents only in the case of a relatively low minor breakage (semi-reset) that does not reach the full reset voltage is secured in the RAM, and the current control data (main control) is stored here. The backup control data obtained by making a backup copy of the control data in the memory is written. In addition, the recovery control data when the RAM that is the control work memory of the electronic device is reset by cutting or the like uses this backup control data in addition to the main recovery control data prepared in advance in the nonvolatile memory. be able to. The backup control data is lost because the RAM is completely reset if a large-scale disruption occurs that makes it impossible to store and store the RAM, and the reset tolerance is as high as the main recovery control data in the nonvolatile memory. Does not have. However, if it is a slight break, it becomes a semi-reset, and the backup control data indicating the state immediately before the break is left in the backup memory, so that the operation can be restored using this. For example, when the main return control data does not indicate the control state immediately before the disconnection (for example, the fixed control state stored in the mask ROM (in the case of a hazard lamp described later, for example, the lighting state: the hazard lighting always after reset reset) Even in the case of a semi-reset, it is possible to reliably return to the operation state before the disconnection from the backup memory in the RAM.

  In the configuration of the present invention, the nonvolatile memory in which the main return fixed memory is formed operates in such a manner that the in-vehicle battery voltage is a direct power supply voltage, and the operation voltage at the time of writing is at the time of reading. Even when the power supply voltage falls below the total reset voltage for fully resetting the stored contents of the RAM, the EEPROM holds the stored contents and the control data in the main control memory is stored. The contents of the backup copy can be written as main return control data.

  With this configuration, the control data indicating the state immediately before the cut is similar to the backup control data described above, and is updated in the EEPROM as main return control data. In this case, the control can be returned to the state immediately before cutting. Also, even when the update write of the main return control data to the EEPROM becomes impossible due to the battery voltage drop, if the subsequent momentary interruption remains semi-reset, the RAM control data immediately before the interruption will be Control can be returned to the state as well. Even when the power supply voltage of the EEPROM is lowered and the main return control data cannot be updated, the control can be returned to the state immediately before the disconnection by the backup control data on the RAM side. Note that the EEPROM includes a flash memory as a concept.

  The on-vehicle electronic device in the configuration of the present invention is configured to sequentially switch to one of a plurality of different operation states each time an operation to the momentary type operation switch is detected, and the main control memory is Each time an operation to the operation switch is detected, the stored control data is rewritten and updated to the content corresponding to the operation state to be switched next, and the device operation control means is updated to the control data in the main control memory. Based on this, it can be considered as a switching control means for switching the operation state of the in-vehicle electronic device.

  When a momentary type switch is used as an operation switch, the switch operation energized state is canceled when the user releases the operation force, and therefore the operation history cannot be held as the physical state of the switch. Therefore, when using a momentary type switch, an unambiguous correspondence is defined between the operation history and the control state, and the presence / absence of an operation is detected by detecting, for example, a signal level change edge by urging the switch, It is necessary to store the control state corresponding to the above correspondence in the work memory (RAM: main control memory) in the form of control data. In this case, if the RAM is reset, the operation history cannot be restored from the physical state of the switch, and the control state of the device immediately before the reset is lost. However, by applying the present invention, control return from the RAM reset state can be performed without any problem even when the momentary type switch as described above is used.

  In the configuration of the present invention described above, the in-vehicle electronic device is a hazard lamp, and the blinking operation state and the extinguishing state can be alternately switched every time an operation to the momentary type operation switch is detected. When the electronic device operated by the momentary type switch is a hazard lamp, the application of the present invention can effectively suppress a problem that the hazard lamp operating before the reset disappears after the reset due to the RAM reset.

  In this case, the nonvolatile memory in which the main return fixed memory is formed operates in such a manner that the in-vehicle battery voltage is a direct power supply voltage, and the operation voltage at the time of writing is higher than the operation voltage at the time of reading. Is set to a high value, and even when the power supply voltage drops below the total reset voltage for resetting all the stored contents of the RAM, it is an EEPROM that retains the stored contents and is a backup copy of the control data in the main control memory. Is written as main return control data, and the RAM constituting the main control memory is connected to the CPU of the microcomputer functioning as the switching control means and the reset return means via an internal bus, The EEPROM constituting the main return fixed memory can be connected to the microcomputer via a serial communication line.

  In the configuration in which an EEPROM that requires time for writing processing or the like is externally connected via a serial communication line, it takes time to update the control data for main return, but the microcomputer (ECU) that constitutes the device operation control means is connected to the microcomputer. The processing burden can be reliably reduced. Since the operation state of the momentary switch changes in a large time span due to human operation, even if it takes time to update the main return control data, the problem does not surface so much. It should be noted that the unlit state when using the blinker is also included in the concept of “unlit state”.

  The configuration of the present invention monitors the power supply voltage of the EEPROM, and if the power supply voltage is higher than a predetermined write guarantee lower limit voltage, the control data in the main control memory is stored in the main return fixed memory. On the other hand, when the power supply voltage falls below the write guarantee lower limit voltage, the control data backup means for writing the control data in the main control memory to the backup memory can be provided. According to this configuration, if the power supply voltage is higher than the write guarantee lower limit voltage, the control data can be written in the main recovery fixed memory of the EEPROM in a form having high reset tolerance, and the voltage drops below the write guarantee lower limit voltage. Can protect the return control data using a backup memory.

  Further, the control data backup means in this case can prohibit rewriting of the main return fixed memory when the power supply voltage falls below the write guarantee lower limit voltage. According to this configuration, when the power supply voltage falls below the write guarantee lower limit voltage, the write operation to the EEPROM is prohibited. There is no need to write control data.

  In the configuration of the present invention, in a state where the power supply voltage is secured higher than the write guarantee lower limit voltage, the control data in the main control memory is written in the backup memory together with the main return fixed memory, and the reset return means In the case of returning from the semi-reset state, if control data is written in the backup memory, the operation return can always be performed based on the stored contents of the backup memory. The backup control data is written to the backup memory regardless of the power supply voltage of the EEPROM, and if backup control data exists at the time of semi-reset recovery, the operation is always restored with the backup control data. Even when the main return control data cannot be written (or cannot be read) to the EEPROM due to a trouble other than an abnormality, the operation can be restored without any problem if it is returned from the semi-reset.

  Further, the reset recovery means in this case, when returning from the semi-reset state, if no control data is written in the backup memory, the reset control means of the main control memory is based on the control data in the main return fixed memory. The stored contents can be restored. According to this configuration, even when the control data is not stored in the backup memory, the operation can be restored based on the control data in the main return fixed memory.

  In the configuration of the present invention described above, the reset return means uses the backup control data in the backup memory and the main return memory when the reset return means returns from the semi-reset state to a voltage higher than the write guarantee lower limit voltage. The contents of the fixed memory can be updated. If the power supply voltage has returned to a voltage higher than the write guarantee lower limit voltage from the semi-reset state, the main return fixed memory can be rewritten normally. However, in the main return fixed memory, rewriting is prohibited before the semi-reset, and the stored contents may not reflect the control state immediately before the semi-reset. According to the above configuration, at the time of semi-reset recovery, the stored contents of both the main control memory and the main return fixed memory are updated to control data reflecting the control state immediately before the semi-reset. Even if the RAM is fully reset, the control state immediately before the previous semi-reset can be reproduced by the control data stored in the main return fixed memory after the reset is completed.

  Further, the backup memory in the present invention can be set in a memory area having a fixed start address in the RAM. According to this configuration, the presence / absence of control data in the backup memory in the RAM can be easily confirmed by a sum check or the like in the memory area having a fixed address. In addition, even when the main control memory is set to relocatable in an application that implements device operation control means, if the main control memory is restored for operation recovery using the stored contents of the backup memory, the restoration process is simplified. can do.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
FIG. 1 is a diagram showing an outline of an electrical block diagram of an in-vehicle electronic device control apparatus according to an embodiment of the present invention. The in-vehicle electronic device control device 100 of FIG. 1 includes a microcomputer 10 that constitutes a control unit, and a nonvolatile external storage device 20 that is connected to the microcomputer 10 via a serial communication line 18. The ECU 10 and the external storage device 20 operate in such a manner that the in-vehicle battery voltage VB is a direct power supply voltage.

  In this embodiment, the microcomputer 10 is a control unit (control circuit) that controls operation of the in-vehicle electronic device 40. As shown in FIG. 1, a CPU 11, a RAM 12 having a work memory 12 a, a ROM 13 for storing various programs, an internal bus 14, an input / output unit (shown as “I / O” in the figure) 15, and other ECUs 200 are connected. A communication interface (indicated as “I / F” in the drawing) 106 connected to the serial communication bus 150, and an external storage device (EEPROM in the present embodiment) 20 and communication connected via the serial communication line 18. An interface 17 is provided.

  A momentary type operation switch 30 and a controller 41 connected to the in-vehicle electronic device 40 are connected to the input / output unit 15. A voltage detection signal for detecting the voltage of the vehicle battery voltage VB is input to the A / D conversion port of the input / output unit 15, and the microcomputer 10 receives the vehicle battery voltage VB according to the input voltage signal. Is monitoring. That is, the circuit unit that detects the voltage of the vehicle battery voltage VB and outputs a voltage detection signal functions as power supply voltage detection means, and the microcomputer 10 functions as power supply voltage monitoring means that monitors the power supply voltage VB by the voltage detection signal. is doing.

  The momentary-type operation switch 30 does not switch a level control signal that directly switches and controls the operation state of the in-vehicle electronic device 40 by a user's urging operation, unlike a push-lock type operation switch. Only a signal serving as a trigger for changing the operation state of the in-vehicle electronic device 40 is generated by the urging operation. The generated trigger signal is input to the microcomputer 10.

  The in-vehicle electronic device 40 is controlled by the microcomputer 10 so that a plurality of different operation states are sequentially switched every time a trigger signal from the operation switch 30 is input to the input unit 15. In response to the input of the level signal from the microcomputer 10, the operation state corresponding to the signal level of the input control level signal is controlled. Further, when the signal level of the input control level signal is switched, the operation state of the in-vehicle electronic device 40 is switched accordingly. The vehicle-mounted electronic device 40 according to the present embodiment is a hazard lamp that is paired on the left and right sides of the vehicle. When the control level signal from the microcomputer 10 input to the hazard controller 41 is switched, the controller 41 receives the control level signal. Depending on the signal level, either a blinking control signal for causing the hazard lamp 40 to blink or an extinguishing control drive signal for turning off the hazard lamp is output to the hazard lamp 40. Thereby, the hazard lamp 40 is switched between two types, a blinking operation state and a light-off state. In addition, the operation control (lighting control) of the hazard lamp includes control for turning on and off the single blinking state when using the blinker.

  In this embodiment, the external storage device 20 is configured as an EEPROM (Electronically Erasable and Programmable Read Only Memory) which is a nonvolatile memory. The EEPROM 20 is composed of a set of memory cells whose memory storage values can be switched between binary values between “1” and “0”, and uses the in-vehicle battery voltage VB as a direct power supply voltage. Works with. Even when the operating voltage at the time of writing is set higher than the operating voltage at the time of reading, and the power supply voltage VB falls below the total reset voltage V0 for fully resetting the stored contents of the RAM 12, the stored contents are retained. Can do. In the erasing mode, erasing processing can be performed only when all the memory cells are collectively set to “1”. In the writing mode, an arbitrary memory cell is changed from “1” to “0”. Processing is possible, and processing for changing from “0” to “1” is impossible.

  The EEPROM 20 has a return memory area (main return fixed memory) 20a in which the contents of a backup copy of control data in the work memory 12a described later are written as main return control data. The main return control data is used to return the vehicle-mounted electronic device 40 to operation when the control data in the work memory 12a is erased by execution of a RAM reset program 13a described later. The return memory area 20 a is not necessarily set in a data storage area provided outside the microcomputer 10, and may be set in a data storage area in the microcomputer 10.

  The RAM 12 operates in such a manner that the in-vehicle battery voltage VB is used as a direct power supply voltage, and the control data indicating the operation state to be commanded to the in-vehicle electronic device 40 corresponds to the transition of the control state. A work area (main control memory) 12a that is stored in an updated form and a backup memory area (backup) that stores backup control data that is a backup copy of the control data in the work area 12a. Memory) 12b. Each time the operation on the operation switch 30 is detected, the work area 12a is rewritten and updated to the contents corresponding to the operation state to be switched next. Each time the work area 12a is updated, the corresponding backup control data is rewritten and updated in the backup memory area 12b.

  The backup memory area 12b is set as a memory area having a fixed start address in the RAM 12. As a result, the presence or absence of control data in the backup memory in the RAM can be easily confirmed by a sum check or the like in the memory area having a fixed address. The work memory 12a may be set to be relocatable in the RAM 12.

  The ROM 13 also includes a RAM reset program 13a that executes a reset process (initialization process) of the RAM 12, and a reset program that resets the operation control (hazard lamp lighting control) of the in-vehicle electronic device 40 after the reset process. 13b, a switch operation monitoring program 13c for monitoring the presence / absence of a trigger signal from the operation switch 30, and control data indicating an operation state to be commanded to the hazard lamp 40 side are stored in the recovery memory area 20a of the EEPROM 20 and the RAM 12 for backup. A hazard lighting state storage program 13d stored in the backup memory area 12b and a hazard lighting control program 13e for switching the lighting state of the hazard lamp 40 between two types of blinking lighting state and extinguishing state are stored. Details of these programs 13a to 13e will be described below with reference to flowcharts shown in FIGS.

  First, the switch operation monitoring program 13c will be described. As shown in FIG. 2, the switch operation monitoring program 13c first maintains a standby state in S11 until a trigger signal generated in response to the operation of the operation switch 30 is detected in S12. The trigger signal is an edge signal of a signal voltage that is input from the operation switch 30 to the microcomputer 10 and that is generated by the switch operation. If this edge is detected, the process proceeds to S13. In S13, the control data currently stored in the work memory 12a is switched to other predetermined control data. Specifically, when the control data currently stored in the work memory 12a is control data for instructing the hazard lamp 40 to turn on and off, the control data is rewritten to control data for instructing the hazard lamp 40 to turn off, and vice versa. In addition, when the control data for instructing the extinguishing state is stored, it is rewritten to the control data for instructing the blinking lighting state. Then, after S13, the program 13c is terminated. The program 13c is repeatedly executed even after the program ends. The switch operation monitoring program 13c is executed by the CPU 11 and functions as a switch operation detection unit that detects an operation on the operation switch 30.

  The hazard lighting state storage program 13d will be described. As shown in FIG. 3, the hazard lighting state storage program 13d monitors the in-vehicle battery voltage VB supplied to the EEPROM 20, reads the voltage VB in S21, and reads the voltage VB in advance in S22. It is determined whether or not the write guarantee lower limit voltage V2 of the EEPROM 20 is higher. The write guarantee lower limit voltage V2 is a predetermined voltage lower limit value at which data can be reliably rewritten in the EEPROM 20. When the voltage VB is higher than the write guarantee lower limit voltage V2, the control data in the work memory 12a of the RAM 12 is written in both the recovery memory area 20a of the EEPROM 20 and the backup memory area 12b of the RAM 12 in S23 and S24. It is. On the other hand, when the voltage VB is lower than the write guarantee lower limit voltage V2, rewriting to the return memory area 20a of the EEPROM 20 is prohibited, and the control data in the work memory 12a of the RAM 12 is stored in the RAM 12 in S25. It is stored only in the backup memory area 12b. When S24 or S25 ends, the program 13d ends. Note that the program 13d is repeatedly executed even after completion. The hazard lighting state storage program 13d is executed by the CPU 11 so that the control data is stored in the RAM storage area 12b or the EEPROM 20 storage area 20a for backup according to the voltage level of the battery voltage VB. And when the voltage VB drops below the write guarantee lower limit voltage V2, it functions as a rewrite prohibiting means for prohibiting rewriting of the nonvolatile memory.

  The hazard lighting control program 13e will be described. As shown in FIG. 4, the hazard lighting control program 13e first reads control data from the work area 12a of the RAM 12 in S31, and in S32, the lighting state (operation) of the hazard lamp 40 indicated by the read control data It is determined whether or not (status) indicates a blinking operation. If the flashing operation is indicated, in S33, the microcomputer 10 outputs a control level signal for causing the hazard lamp 40 to flash to the hazard controller 41, and the hazard lamp 40 is controlled to flash. . On the other hand, if the read control data does not indicate a blinking operation, the microcomputer 10 outputs a control level signal for turning off the hazard to the hazard controller 41 in S34 so that the hazard lamp 40 is turned off. Be controlled. When S33 or S34 ends, the program 13e ends. The program 13e is repeatedly executed even after the program 13e is finished. The hazard lighting control program 13e is executed by the CPU 11, and thereby device operation control means for controlling the operation of the in-vehicle electronic device 40 based on the control data in the work memory 12a according to the voltage level of the battery voltage VB, And it functions as a switching control means for switching the operating state of the in-vehicle electronic device 40 based on the control data in the work memory 12a.

  As described above, by executing the programs 13c, 13d, and 13e, the microcomputer 10 stores the operation control command information (control data) of the hazard lamp 40 in the work area 12a of the RAM 12, and this operation control command. Based on the information, the control level signal of the hazard lamp 40 is output, and the lighting control of the hazard lamp 40 is executed.

  However, the operation control command information (control data) stored in the work area 12a of the RAM 12 may be cleared by reset processing of the RAM 12. Therefore, the operation control command information (control data) is also stored for backup in a storage area other than the work area 12a of the RAM 12. Hereinafter, the RAM reset program 13a for resetting the RAM 12 will be described.

  As shown in FIG. 5, the RAM reset program 13a first reads a value related to the in-vehicle battery voltage VB in S101. Subsequently, in S102, it is determined whether or not the read voltage VB has dropped to a voltage level at which a semi-reset is to be performed. Regarding the reset of the RAM, the total reset voltage V0, which is a voltage threshold for fully resetting the stored contents of the RAM 12, and a value higher than the total reset voltage V0 and lower than the write guarantee lower limit voltage V2 of the EEPROM 20 are determined. Since the backup control data in 12b is protected and the semi-reset voltage V1 which is a voltage threshold for the semi-reset process for resetting only the work memory 12a is set, in S102, the read voltage VB is changed to the semi-reset voltage V1. The determination is made based on whether or not the voltage has fallen below the reset voltage V1. If not, the program 13a is terminated without performing either the full reset process or the semi-reset process. On the other hand, if it is descending, the process proceeds to S103. In S103, it is determined whether or not the voltage VB read in S101 has dropped below the total reset voltage V0. If it is lowered, all the reset processing is performed in S104 and S105, and the program 13a is terminated. On the other hand, if it is not lowered, the semi-reset process is performed in S106 and S107, and the program 13a is terminated. The all reset process and the semi-reset process are performed by performing a zero check on the reset target storage area after performing a verify check on the reset target storage area. The program 13a is repeatedly executed after the end. The RAM reset program 13a is executed by the CPU 11 and functions as a RAM reset means for executing the full reset process and the semi-reset process.

  Note that the RAM reset program 13a is not only executed in a form of periodically monitoring the decrease in the in-vehicle battery voltage VB, but an external reset signal is input to the input / output unit 15 of the microcomputer 10 due to other factors. And may be executed.

  Then, after the RAM reset is executed, the return processing from the reset state is executed. When the all reset process is executed, when the battery voltage VB returns, the in-vehicle electronic device 40 is returned to operation using the reset return control data stored in the return memory area 20a of the EEPROM 20.

  If the battery voltage VB is restored after the semi-reset process, the vehicle-mounted electronic device 40 is restored to operation using the backup control data. Specifically, the return process is performed by executing the post-reset return program 13b shown in FIG. The reset program 13b after reset first determines whether or not the backup control data is correctly written in the backup memory area 12b of the RAM 12 by executing, for example, a sum check or a mirror check in S111. If there is a correctly written data, the stored contents of the work memory 12a are restored using the backup control data stored in the back memory area 12b in S112, and the vehicle-mounted electronic device 40 is returned to operation. At this time, when the battery voltage VB returns from the semi-reset state to a voltage higher than the write guarantee lower limit voltage V2, not only the work memory 12a but also the EEPROM 20 is stored in the backup memory 12b. The contents of the return memory area 20a are also updated so that all subsequent reset processes can be handled. On the other hand, if not correctly written, the stored contents of the work memory 12a are restored using the reset return control data stored in the return memory area 20a of the EEPROM 20 in S113, and the in-vehicle electronic device 40 is operated. Return.

  The program 13b is executed by the CPU 11 after executing the semi-reset process, and functions as a reset return means for returning the operation of the in-vehicle electronic device 40.

  As mentioned above, although embodiment of this invention was described, this invention is not limited to the above-mentioned embodiment, The following embodiment is also contained in the technical scope of this invention, and also the summary other than the following is also included. Various modifications can be made without departing from the scope. In the above embodiment, a hazard lamp is illustrated as an in-vehicle electronic device. However, the present invention is not limited to this. For example, any electronic device or function can be used as long as the backup method can be adopted. There may be.

The block diagram which shows the electric constitution of one Embodiment of the vehicle-mounted electronic device control apparatus of this invention. The flowchart explaining the flow of a switch operation monitoring process. The flowchart explaining the flow of a hazard lighting state storage process. The flowchart explaining the flow of a hazard lighting control process. The flowchart explaining the flow of RAM reset processing. The flowchart explaining the flow of the reset process after reset.

Explanation of symbols

100 On-vehicle electronic device control device 10 Microcomputer (control unit)
11 CPU (apparatus operation control means (switching control means), RAM reset means, reset return means, control data backup means)
12 RAM
12a Work memory (main control memory 12a)
12b Backup memory area (backup memory 12b)
13 ROM
20 EEPROM (nonvolatile memory)
20a Memory area for return (main return fixed memory 20a)
30 Momentary type operation switch 40 On-vehicle operating equipment (hazard lamp)
VB In-vehicle battery voltage V0 Total reset voltage V1 Semi-reset voltage V2 Write guarantee lower limit voltage V2

Claims (11)

The control data indicating the operation state to be commanded to the in-vehicle electronic device is updated in a form corresponding to the transition of the control state. Main control memory to store,
Device operation control means for controlling the operation of the in-vehicle electronic device based on the control data in the main control memory;
Main return fixed memory in which main return control data is written, which is formed in a non-volatile memory and returns the operation of the in-vehicle electronic device when the control data in the main control memory is erased by a RAM reset. When,
A backup memory provided separately from the main control memory in the RAM, in which backup control data obtained by making a backup copy of the control data in the main control memory is written while being updated together with the main control memory;
While monitoring the power supply voltage of the RAM, if the power supply voltage falls below a predetermined total reset voltage, all the stored contents of the RAM including the main control memory are reset, and the power supply voltage is: A RAM that performs a semi-reset process that resets the main control memory while protecting the backup control data in the backup memory when it falls below a predetermined semi-reset voltage that is higher than the total reset voltage Resetting means;
When the power supply voltage is restored from the all reset state, the vehicle-mounted electronic device is returned to operation using the reset return control data, while when the voltage is restored from the semi-reset state, the backup control data is Reset return means for returning the operation of the in-vehicle electronic device using,
A vehicle-mounted electronic device control device comprising:   The nonvolatile memory in which the main return fixed memory is formed operates in such a manner that the in-vehicle battery voltage is a direct power supply voltage, and the operation voltage at the time of writing is higher than the operation voltage at the time of reading. The EEPROM that holds the stored contents even when the power supply voltage is lower than the total reset voltage that resets all the stored contents of the RAM, and is a backup copy of the control data in the main control memory Is written as the main return control data. The on-vehicle electronic device control device according to claim 1. The in-vehicle electronic device is configured to sequentially switch to any one of a plurality of different operation states each time an operation to a momentary type operation switch is detected,
Each time the operation to the operation switch is detected, the main control memory is rewritten and updated to the contents corresponding to the operation state to be switched next, and the stored control data is updated.
3. The on-vehicle electronic device control device according to claim 1, wherein the device operation control unit is a switching control unit that switches an operation state of the on-vehicle electronic device based on the control data in the main control memory. .   4. The vehicle-mounted electronic device according to claim 3, wherein the vehicle-mounted electronic device is a hazard lamp, and a blinking operation state and a light-off state are alternately switched every time an operation to the momentary type operation switch is detected. Control device.   The RAM comprising the requirement according to claim 2 and constituting the main control memory is connected to a CPU of a microcomputer functioning as the switching control means and the reset recovery means via an internal bus, and 5. The in-vehicle electronic device control device according to claim 4, wherein the EEPROM constituting the return fixed memory is connected to the microcomputer via a serial communication line.   The power supply voltage of the EEPROM is monitored, and when the power supply voltage is higher than a predetermined write guarantee lower limit voltage, the control data in the main control memory is written to the main return fixed memory, while the power supply voltage 6. The vehicle-mounted device according to claim 2, further comprising: a control data backup unit that writes control data in the main control memory to the backup memory when the voltage drops below the write guarantee lower limit voltage. Electronic equipment control device.   The in-vehicle electronic device control device according to claim 6, wherein the control data backup unit prohibits rewriting of the main return fixed memory when the power supply voltage falls below the write guarantee lower limit voltage. In a state where the power supply voltage is secured higher than the write guarantee lower limit voltage, the control data in the main control memory is written to the backup memory together with the main return fixed memory,
The reset return means, when returning from the semi-reset state, always returns the operation based on the stored contents of the backup memory when the control data is written in the backup memory. The vehicle-mounted electronic device control apparatus of any one of Claim 2 thru | or 7.   The reset return means returns from the semi-reset state, and when the control data is not written in the backup memory, the main control memory is based on the control data in the main return fixed memory. The in-vehicle electronic device control device according to claim 8, which restores the stored content.   When the reset recovery means recovers from the semi-reset state to a voltage higher than the write guarantee lower limit voltage, the main control memory and the main return fixed memory using the backup control data in the backup memory The vehicle-mounted electronic device control apparatus of any one of Claim 2 thru | or 9 which updates the content of these.   The vehicle-mounted electronic device control device according to any one of claims 1 to 10, wherein the backup memory is set in a memory area where a head address is fixed in the RAM.

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