JPH0512645B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a data processing device, for example a data processing device for storing and displaying travel data of a motor vehicle.

In automobiles, the rotational speed of the propulsion shaft, such as the output shaft of the transmission, is used as mileage data by the mileage recorder (odometer) and trip mileage recorder (trip odometer) installed as necessary. Therefore, it is integrated (counted) and held.

Known odometers and trip odometers include:
It consists of a mechanical counter with a rotating drum-shaped data display section.

However, when such a mechanical trip meter is used, it becomes difficult to downsize and consolidate the display panel etc. due to the size of the mechanical part.

Therefore, the inventors of the present invention conceived the idea of directly importing the data necessary for display from each sensor of the automobile into a microcomputer, performing arithmetic processing, and displaying the data.

In order to process data in a car using a microcomputer, for example, it is required to record and retain mileage data sequentially, and it is also required to retain data even when the power is turned off. will be done. This problem can be solved by using semiconductor nonvolatile memory, which can retain data even when the power is turned off.

However, as mentioned above, in addition to the problem of data retention, it is also necessary to record the data sequentially. Using semiconductor non-volatile memory makes it difficult to achieve sufficient processing speed and record data a sufficient number of times.

The purpose of the present invention is to solve this problem, that is, to realize both sequential storage with high processing speed and storage when the power is cut off.

The present invention receives a signal from a sensor connected to an automobile, processes the signal using a microcomputer, and stores the result in a primary storage device, which is erased by turning off a key switch. For data that should not be lost, that is, mileage data, the data is transferred from the primary storage device to non-volatile memory by the microcomputer based on the key switch being turned off, and the data is transferred by the microcomputer based on the key switch being turned on. It is used to transfer data from non-volatile memory to primary storage.

This allows data to be recorded sequentially in the primary storage device and retained as needed in the non-volatile memory.
Furthermore, by writing to the nonvolatile memory as needed, it is possible to reduce the number of writes, which has the effect of significantly improving the reliability of the device.

In addition, signals from car sensors, etc. are input directly to the microcomputer, and the data is processed based on the microcomputer's program, so just by changing the commands and data in the program, it can be applied to various car models. We can accommodate you.

Furthermore, with the present invention, signals were conventionally processed using individual components connected to each sensor.
It is composed of only one common part, a microcomputer, which greatly reduces the number of parts and reduces the failure rate, which also has the effect of providing highly reliable automobile parts.

Another object of the present invention is to provide a driving data storage and display device for an automobile whose display panel can be easily downsized and consolidated.

Another object of the present invention is to provide a novel automobile travel data storage and display device that allows electronic meters and the like.

Another object of the present invention is to provide a display data storage and display device capable of forming accurate display data.

Further objects of the invention will become apparent from the following description and drawings.

Hereinafter, this invention will be explained in detail based on examples.

FIG. 1 shows a circuit diagram of one embodiment of the invention.

In the figure, 1 is a battery, 2 is a key switch, 3 is a power supply starting circuit, 4 is a constant voltage circuit, 5 is a key switch on detection circuit, and 6 is a key switch cutoff detection circuit.

As shown in the figure, the power supply starting circuit 3 includes a PNP transistor Q ₂ as a power switch, a control
npn transistor Q ₁ , backflow prevention diode D ₁ ,
Inverter circuit IV as a buffer amplifier circuit,
Reset flip-flop circuit for operation maintenance
It consists of RSF, delay circuit DLY, and resistors _R1 to _R4 . Note that, although not particularly limited, the above-mentioned flip-flop circuit RSF and inverter circuit
IV is supplied with the output voltage of the constant voltage circuit 4 as a power supply voltage.

If key switch 2 is turned off,
Transistor Q ₁ is turned off, and accordingly transistor Q ₂ is also turned off. Therefore, the power of the battery 1 is not consumed.

When the key switch 2 is turned on, a bias current is supplied to the base of the transistor _Q1 from the battery 1 through the key switch 2, the diode _D1 , and the resistor _R4 , and as a result, the transistor Q1 is turned on. be made into

The transistor Q ₂ is turned on by the on-state of the transistor Q ₁ . Constant voltage circuit 4
is supplied with battery voltage via the transistor _Q2 . As a result, the voltage Vcc as the power supply voltage supplied from the constant voltage circuit 4 to the circuit described later
is output. Although not particularly limited, the above voltage Vcc
is taken to a value such as 5 volts.

As shown in the figure, the key switch ON detection circuit 5 is composed of an AND circuit _A1 , a capacitor C, and a resistor _R5 that constitute a differential circuit, and after the key switch 2 is turned on, the capacitor C is
A high level signal (logical value 1) is output only for a period determined by the time constant of the resistor _R5 .

The flip-flop circuit RSF in the power supply start-up circuit 3 is connected to the key switch-on detection circuit 5.
It is set to a set state by a high level signal supplied from the circuit, and outputs a low level signal (logical value 0), which is almost the ground potential of the circuit, to its inverted output terminal. Inverter circuit IV outputs a high level signal by receiving the output signal of flip-flop circuit RSF. As a result, the transistor _Q1 is supplied with a bias current to its base via the resistor _R3 , and is turned on regardless of the switch state of the key switch 2.

When the key switch 2 is turned off from the on state, the key switch cutoff detection circuit 6 outputs a signal that is kept at a high level for a predetermined period after the key switch 2 is turned off.

The delay circuit DLY in the power supply startup circuit 3 outputs a signal delayed by a predetermined time with respect to the output signal of the circuit 6. The above flip-flop circuit
RSF is reset by the output signal of the delay circuit LLY.

As a result, the transistors Q ₁ and Q ₂ in the power supply starting circuit 3 are turned off after a predetermined time has elapsed since the key switch 2 was turned off. As will become clear from the explanation that follows, the above delay time is made longer than the time required to write data to the electrically rewritable semiconductor nonvolatile memory 9.

The key switch cutoff detection circuit 6 is composed of delay type flip-flop circuits FF ₁ and FF ₂ and an AND circuit A ₂ as shown in the figure, although this is not particularly limited.
The clock terminals CP of the delay type flip-flop circuits _FF1 and _FF2 are supplied with a clock pulse φ from a reference pulse generation circuit 15, which will be described later. The flip-flop circuits FF ₁ and FF ₂ take in a signal supplied to their data input terminal D in synchronization with the falling edge of the clock pulse φ, and output the signal, which is taken in in synchronization with the rising edge of the clock pulse φ, in a non-inverted manner. The configuration is such that it outputs to a terminal Q and an inverted output terminal.

In addition, the above flip-flop circuits FF ₁ and FF ₂
is AND circuit A ₂ when the key switch is turned on.
In order to prevent an erroneous signal from being output from the key switch input detection circuit 5, they are set to the same state by the output of the key switch input detection circuit 5. In the illustrated case, flip-flop circuits FF ₁ and FF ₂ are placed in a reset state by having their reset terminals R coupled to the output terminal of circuit 5.

The data input terminal D of the flip-flop circuit _FF1 is connected to the battery 2 via the key switch 2, and its level is therefore determined by the state of the key switch 2.

With the above configuration, the above flip-flop circuit
After the key switch 2 is turned on, the output terminals Q of FF ₁ and FF ₂ are sequentially brought to a high level in accordance with the clock pulse φ, and are maintained at a high level as long as the key switch is kept on thereafter. When the key switch 2 is turned off from the on state, the flip-flop circuits FF ₁ and FF ₂
The output terminal Q of is set to a low level in accordance with the clock pulse. As a result, the key switch cutoff circuit 6 outputs a high level signal for a period equal to one cycle of the clock pulse φ after the key switch 2 is turned off.

Reference numeral 7 denotes a write voltage generation circuit whose operation is controlled by the output of the key switch cutoff detection circuit 6.
This is provided in response to configurations that require a relatively high level of write voltage, such as 25 volts.

The write voltage generation circuit 7 outputs the write voltage in response to the output signal of the detection circuit 6 being set to a high level, and when the output signal of the detection circuit 6 is set to a low level, it is approximately Vcc.
Alternatively, it is configured to output a voltage at the level of the circuit's ground potential.

Reference numeral 8 denotes a read/write control circuit activated by the output signals of the key switch on detection circuit 5 and the key switch cutoff detection circuit 6.

This read/write control circuit 8 is activated by the output of the key switch input detection circuit 5, and thereby outputs signals and signals to be supplied to the chip selection terminal of the semiconductor nonvolatile memory 9 and a plurality of address input terminals Ai. Serial parallel conversion register 11
It is configured to output a clock pulse _φ1 for a predetermined period.

Further, the read/write control circuit 8 is activated by the output of the key switch cutoff detection circuit 6, and supplies data to the chip selection terminal of the semiconductor nonvolatile memory 9, the program terminal PGM, and a plurality of address input terminals Ai. It is also configured to output a signal for converting and a clock pulse φ ₂ for supplying to the parallel-to-serial conversion register 12 only for a predetermined period.

The semiconductor non-volatile memory 9 is provided to store mileage data of the automobile. This semiconductor nonvolatile memory 9 is known per se, for example, MNOS (Metel Nitride Oxide).
It includes a plurality of memory cells made up of non-volatile memory elements, such as semiconductor (Semiconductor) elements, in which data can be electrically written and erased.

The memory 9 is configured to receive the output voltage Vcc of the constant voltage circuit 4 as a power supply voltage, although this is not particularly limited.

The memory 9 has an appropriate internal configuration. As a result, the memory data of the memory cells selected by the address signals supplied to the plurality of address input terminals Ai are changed in response to the chip selection terminal being set to a low level such as approximately the ground potential. In the selected state, the terminal
Regardless of what level VPP and PGM are set to, they will be supplied to the data input/output terminal I/O.

Also, when the chip select terminal is set to a high level such as approximately Vcc level, the write voltage input terminal VPP is set to a write voltage level such as approximately +25 volts, and the program terminal
When PGM is set to a high level such as the Vcc level, data supplied to the data input/output terminal I/O is written into the selected memory cell.

Although not particularly limited, the data unit stored in the semiconductor nonvolatile memory 9 has a relatively small number of bits, such as a 1-bit configuration. In contrast, automobile mileage data is composed of ten or more bits or more. Therefore, the mileage data is stored across a plurality of storage addresses in the semiconductor nonvolatile memory 9.

When the key switch 2 is turned on, a detection signal is outputted from the key switch activation detection circuit 5 in response to this, and the read/write control circuit 8 is activated by the detection signal.

Upon the activation, the control circuit 8 outputs a low-level chip selection signal, and then outputs a plurality of address signals for scanning each address of the memory 9.

In response to the plurality of address signals, the mileage data previously stored at a plurality of addresses in the memory is serially read out.

The control circuit 8 also outputs a serial-to-parallel conversion clock pulse φ ₁ in synchronization with each of the plurality of address signals.

Therefore, the data output from the memory 9 is input to the serial/parallel conversion register 10 and held there.

After a predetermined number of address signals have been output, the control circuit 8 is brought into a non-operational state by appropriately configuring its internal circuitry.

When the key switch 2 is cut off, a detection signal is output from the key switch cut-off detection circuit 6 in response to this, and the write voltage generation circuit 7 is activated by the detection signal, and the control circuit 8 is activated again. Ru.

As a result of the activation, the control circuit 8 first outputs the setting clock pulse φs, and in response, the current mileage data output from the adder circuit 21 (described later) is transferred to the parallel-serial conversion register 11.
is set to

After the clock pulse φs is output, the control circuit 8 outputs a plurality of parallel-to-serial conversion clock pulses _φ2 . The parallel-to-serial conversion register 11 serially outputs the set data in synchronization with the clock pulse _φ2 .

The control circuit 8 outputs a control clock pulse φc which is set to a high level during this restart state, and the AND circuit 11' is opened accordingly. Therefore, the serial output data of the register 11 is supplied to the data input/output terminal I/O of the memory 9 via the AND circuit 11'.

The control circuit 8 further outputs a program signal set to high level in synchronization with the clock pulse φ ₂ and a plurality of address signals for scanning a plurality of addresses in the memory 9.

In this case, the write voltage input terminal VPP of the memory 9 has +25
A write voltage such as volts is supplied.

Therefore, under the control of the control circuit 8,
The serial output data output from the register 11 will be sequentially written into the memory 9.

12 is a rotation sensor. This rotation sensor 1
2 includes, but is not particularly limited to, a rotating shaft SH having magnets MG coupled at equal intervals around the rotating shaft SH, and a reed switch LS disposed close to the rotating shaft SH. The rotating shaft SH is connected to an output shaft of a transmission of an automobile, and is rotated at a rotation speed proportional to the rotation speed of the output shaft.
The reed switch LS is driven by the magnet MG.

The above reed switch LS has one end connected to the ground point of the circuit and the other end connected to a resistor as shown in the diagram.
It is connected to the output terminal of the constant voltage circuit 4 via _R6 .

Therefore, at the other end of the reed switch LS,
A pulse signal with a period proportional to the traveling speed of the vehicle is output.

A waveform shaping circuit 13 outputs a pulse signal having a desired level and rise/fall characteristics in response to the pulse signal supplied from the rotation sensor 12. The waveform shaping circuit 13 is designed to ignore noise such as pulse noise added to the output pulse signal of the rotation sensor 12 due to the chatter of the reed switch LS or various undesirable electrical couplings to the signal line. It is said that the structure is

14 is a counter that counts the pulse signals supplied from the waveform shaping circuit 13.

Reference numeral 15 denotes a reference pulse generation circuit for forming clock pulses φ, φ ₃ and φ ₃ ', and is composed of circuits such as an oscillation circuit, a frequency dividing circuit, and a gate circuit (not shown).

The clock pulse φ is supplied to the key switch cutoff detection circuit 6 as described above, and its period is determined by the pulse width of the signal to be outputted from the detection circuit 6.

The clock pulse _φ3 is supplied to the reset terminal R of the speed counter 14, and its cycle is determined by the count cycle to be set.

The above clock pulse φ ₃ ' is applied to the next latch circuit 1.
6, and output immediately before the clock pulse _φ3 .

Therefore, the speed counter 14 is set with data having a value equal to the number of input pulse signals in each count period, that is, data having a value proportional to the traveling speed of the automobile. The set data of the speed counter 14 is set in the latch circuit 16 each time the clock pulse φ ₃ ' is output.

17a is an arithmetic circuit for converting the data output from the latch circuit 16 into traveling speed data to be displayed. This arithmetic circuit 17a
essentially consists of a fixed data generation circuit and a digital multiplication circuit. The above latch circuit 16
The output data of and the output fixed data of the fixed data generation circuit are supplied to the digital multiplication circuit as multiplicand data and multiplier data, respectively.

The output fixed data of the above fixed data generation circuit is
The value is determined in advance according to the characteristics of the driving system mechanism of the automobile used, the drive shaft rotation speed versus output pulse number characteristics of the rotation sensor 12, the count period, and the conversion data unit.

As a result, the arithmetic circuit 17a outputs Km/h.
Alternatively, traveling speed data converted into a unit such as km/h is output.

A display decoder 18a forms signals for driving each display segment of the display 19a by decoding the speed data signal output from the arithmetic circuit 17a.

Although not particularly limited, the display 19a is composed of a liquid crystal display having a plurality of bar-shaped display segments _S1 to Sn and a common electrode BP as shown in FIG.

In response to this, the display decoder 18a is configured to have a signal conversion characteristic such that the display segments _S1 to Sn make the travel speed data in the form of a bar graph.

20 is an odometer counter that counts the pulse signal output from the waveform shaping circuit 13.

The counter 20 is brought into a reset state when the key switch 2 is turned on because its reset terminal R is connected to the output terminal of the key switch turn-on detection circuit 5. The counter 20 is not reset while the key switch 2 is turned on.

Therefore, the count number in the counter 20 is:
This corresponds to the distance traveled by the car during the period when the key switch 2 is turned on.

The output data of the counter 20 and the output data of the serial/parallel conversion register 10, that is, the mileage data of the automobile before the key switch 2 is turned on, are added by an adding circuit 21. Therefore, the adding circuit 21 outputs the total mileage data of the automobile.

25 is a display selection circuit provided as necessary, and 22 and 23 are AND gate circuits whose gates are controlled by the display selection circuit. The display selection circuit 25 is controlled by a switch 26 such as the one provided on the instrument panel of an automobile.

One of the AND gate circuits 22 and 23 is opened depending on the state of the switch 26.

As a result, either the mileage data while the key switch is turned on outputted from the odometer counter 20 or the total mileage data outputted from the addition circuit 21 is supplied to the OR circuit 24 via the gate 22 or 23. That will happen.

17b is an arithmetic circuit, and the arithmetic circuit 17
It has a similar configuration to a. That is, it is substantially composed of a fixed data generation circuit and a digital multiplication circuit. By appropriately setting the output fixed data of the fixed data generation circuit in accordance with the characteristics of the traveling system mechanism and the characteristics of the drive shaft rotation speed versus the number of output pulses in the same manner as described above, the output fixed data from the arithmetic circuit 17b is
Mileage data converted to units such as Km or Km is output.

18b is a display decoder, and 19b is a display.

The display 19b includes a display segment for displaying a multi-digit number as shown in FIG. 3, a decimal point display segment Sdb, and a common electrode.
Consists of a liquid crystal display with BP.

In response to this, the display decoder 18b is configured to have signal conversion characteristics that display the mileage data using a multi-digit number pattern.

According to the above embodiment, most parts of the conventional speed data display device and mileage data storage display device can be implemented as electronic circuits. There is no need to arrange a relatively large device such as a conventional mechanical counter on the back side of the display panel, and as a result, the display panel portion can be made relatively compact.

Different types of data can be displayed on one display, and as a result, more data can be displayed even though the display area is made relatively small.

By configuring the power supply starting circuit 3 as shown in the figure and supplying power to other circuits shown in the figure through the power supply starting circuit 3, it is possible to turn off the key switch. The unnecessary consumption of the battery 1 when the battery 1 is turned off becomes negligible.

The above embodiments can be modified or improved in various ways.

For example, while data such as travel speed data is preferably displayed at all times while the vehicle is running or being driven, data such as travel distance data does not necessarily need to be displayed at all times.

Therefore, a display blanking instruction signal may be supplied to the display decoder 18b, for example by providing a suitable switch.

The illustrated key switch input detection circuit 5 is an example. The detection circuit 5, like the key switch cutoff detection circuit 6, may be composed of a flip-flop circuit and a gate circuit. In this case, the detection signal is output from the circuit 5 after a sufficient level of power supply voltage is output from the constant voltage circuit 4 by the read/write control circuit 8, counter 20, etc.
As a result, the counter 20 can be reset and the read/write control circuit 8 can be activated more reliably.

Semiconductor non-volatile memory 9 when the key switch is turned on
The data output from the odometer counter 20 may be set directly or via the serial/parallel conversion register 10. In this case, the counter 20 adds up the previous mileage data and the new mileage data. Therefore, it is not necessary to provide the adder circuit 21, the gate circuits 22 to 24, and the display selection circuit 25, and the circuit configuration can be simplified.

The fixed data generation circuits as described above in the arithmetic circuits 17a and 17b can, for example, be made programmable using suitable switches or suitable non-volatile memories.

In this case, the circuit device shown in FIG. 1 can be applied to automobiles with various characteristics because the fixed data can be arbitrarily set. Furthermore, even if the distance traveled versus the number of output pulses varies due to changes in the diameter of the car's tires, more accurate mileage data can be displayed by appropriately modifying the above fixed data. You will be able to do so.

The illustrated device may be used in conjunction with conventional mechanical odometer display devices, if desired. In this case, by arranging the illustrated display 19b on the instruction panel, the mechanical mileage display device can be installed at any location in the automobile. As a result, even in this manner, the various advantages of using the illustrated apparatus are not substantially impaired.

FIG. 4 shows an example in which the fixed data generation circuits in the arithmetic circuits 17a and 17b are integrated. In the figure, the arithmetic circuit 17a is
The fixed data generation circuit 17a ₂ is composed of a multiplication circuit 17a ₁ and a fixed data generation circuit 17a ₂ , and the arithmetic circuit 17b is composed of a multiplication circuit 17a ₁ and a fixed data generation circuit 17a ₂ . , resistors R ₇ to R ₈ and switches K ₁ to K ₂ . The fixed data supplied to the multiplication circuit _17a1 is determined by the combination of the switch states of the switches _K1 to _K2 .

The fixed data to be supplied to the multiplication circuit 17a ₁ and the fixed data to be supplied to the multiplication circuit 17b ₂ are the unit of data to be obtained by the multiplication circuit 17a ₁ and the data to be obtained by the multiplication circuit 17b ₁ . If the unit of and the count period of the speed counter 14 are fixed, a one-to-one correspondence is possible.

Therefore, in FIG. 4, the fixed data generating circuit _17b2 is substantially the same as the fixed data generating circuit 17.
It consists of a data conversion circuit such as a decoder to which the output of _b2 is supplied.

According to the configuration shown in FIG. 4, it is sufficient to set common fixed data for the multiplier circuits 17a ₁ and 17b ₂ , and therefore the circuit operation can be simplified.

FIG. 5 shows an example in which the travel speed display 19a and the travel distance display 19b are driven by a common display decoder 18. In the figure, output data from the arithmetic circuit 17a or 17b is supplied to a display decoder 27 in a time-sharing manner via a selection circuit 27 controlled by a display control circuit 28. The display devices 19a and 19b are operated in a time-sharing manner by the display control circuit 28.

As a result, the output data of the arithmetic circuit 17a is displayed on the display 19a, and the output data of the arithmetic circuit 17b is displayed on the display 19b.

FIG. 6 shows a circuit of another embodiment of the invention.

In the figure, 30 is a microcomputer, which includes, but is not limited to, an analog multiplexer (MPX) 31, an analog-to-digital conversion circuit (ADC) 32, a register (REG) 33, an arithmetic logic unit (ALU) 35, and a control circuit 36. ,
It is composed of a reference pulse generation circuit 37, a read only memory (ROM) 38, a random access memory (RAM) 39, a data buffer 40, and an address buffer 41.

Various instructions constituting various programs and various fixed data are written in the ROM 38.

Each storage address of the ROM 38 is designated by an address signal supplied from the control circuit 36 via the address path IAB. Above ROM
The output information of 38 is supplied to various circuits such as the control circuit 36 and ALU 35 via the data bus IDB.

The control circuit 36 includes known circuits such as a program counter, stack pointer, working register, instruction decoder, and control pulse generation circuit (not shown).

The control circuit 36 outputs control signals to be supplied to various circuits based on instructions output from the ROM 38.

_S1 and _S2 are analog sensor circuits.

The sensor circuit _S1 includes, for example, a thermistor (not shown) for detecting engine cooling water temperature, an appropriate bias circuit for the thermistor, an operational amplifier circuit, and the like.

The sensor circuit _S2 is similarly composed of, for example, a thermistor whose heat dissipation coefficient is changed by the residual fuel in the fuel tank, a bias circuit that causes the thermistor to self-heat, an operational amplifier circuit, and the like.

As a result, the sensor circuits S ₁ and S ₂ output an analog voltage proportional to the engine coolant temperature and the remaining amount of fuel.

_S1 to _S4 are digital sensor circuits.

The sensor circuit _S3 is configured with, for example, an engine crank sensor. This sensor circuit _S3 outputs a pulse signal in response to when the engine crank angle is set to a specific angle such as 0°.

The sensor circuit _S4 is comprised of a rotation sensor 12 and a waveform shaping circuit 13 as shown in FIG.

In this embodiment, the analog sensor circuits S ₁ to S ₂ and the digital sensor circuits S ₃ to
The signals output from _S4 and key switch 2 are:
By executing the input program stored in the ROM 38, the data is written into corresponding storage addresses in the RAM 39 in a time-division manner.

For example, the output signal of the sensor circuit S ₁ is written into the corresponding storage address of the RAM 39 as follows.

That is, first, the analog multiplexer 31
is controlled and as a result the above sensor circuit S ₁
The output signal is supplied to an analog-to-digital conversion circuit (ADC) 32. The above output signal is the above
converted into a digital signal by ADC32,
It is set in register 33.

Next, by controlling the register 33, the digital signal is supplied to the data bus IDB.

Next, the above RAM3 is connected via the address bus IAB.
9 is supplied with a predetermined address signal and a write control signal. As a result, the digital signal on the data bus IDB is written into a predetermined address of the RAM 39.

Similarly, by controlling the analog multiplexer 31, the register 33, and the RAM 39, the analog signal output from the sensor circuit _S2 is converted into digital data and written into the corresponding address of the RAM 39.

Each bit (not shown) of the digital signal input register 34 is set by a pulse signal output from the corresponding digital sensor circuits _S3 to _S4 and key switch 2, respectively.

The data in the register 34 is similarly written into the corresponding address of the RAM 39 via the data bus IDB.

The input data written in the RAM 39 is used in executing various programs written in the ROM 38. Various data formed by executing various programs are rewritten into the RAM 39 as necessary.

A data unit change program is executed to process the data input from the sensor circuits S ₁ to S ₂ .

Although not particularly limited, a program for changing digitized analog data is configured to execute an interpolation method. Accordingly, the ROM 38 includes, for example, a sensor circuit S ₁
Sampling data determined based on the temperature-voltage conversion characteristics of is prepared in advance.

By executing the data unit change program using the ALU 35, the sampling data closest to the input engine coolant temperature data in voltage units is referenced, and the referenced sampling data is then changed to the input engine coolant temperature data. interpolated accordingly. As a result, engine coolant temperature data in units such as degrees Celsius corresponding to the input engine coolant temperature data is formed, and the RAM 39
written inside.

Similarly, based on the input fuel remaining data,
Percentage fuel remaining data is formed.

A display decoding program prepared in the ROM 38 as required is executed. As a result, based on the engine coolant temperature data converted as described above, segment data for driving the display segments of the display device, which will be described later, is formed.
Written into RAM39. Similar segment data is formed based on the remaining fuel amount data.

The alarm program checks for engine coolant temperature abnormalities. If an overheating condition is detected in this manner, overheating display data is set in a predetermined bit at a predetermined address in the RAM 39.
Similarly, if the residual amount of superheat is reduced below a predetermined value, fuel warning data is set.

The crank angle pulse output from the sensor circuit _S3 is regarded as engine rotation speed data.

The pulses output from the sensor circuit _S4 are considered as travel speed and travel distance data, as in the previous embodiment.

Pulse signals output from these sensor circuits are counted by a pulse counting program and written into corresponding addresses in the RAM 39.

For example, by a counting program,
The bit associated with the sensor circuit _S3 at a predetermined address in the RAM 39 is checked, and if the bit has been changed from 0 to 1, the address to be used as the counter in the RAM 39, that is, the counter address to 1
is added. By supplying a clock pulse from the reference pulse generation circuit 37, the data in the counter address is written into the address of the RAM 39 that should be the engine rotation speed recording address, and then the data in the counter address is written into the address that should be the engine rotation speed recording address. cleared. Therefore, data equal to the number of crank angle pulses generated in one period of the clock pulse is set in the engine rotational speed storage address.

Similarly, by checking the bit corresponding to the sensor circuit _S4 of the RAM 39,
Traveling speed data is formed and written into RAM 39. In addition, the above traveling speed data may be
By adding the data in the trip mileage storage address and the data in the total mileage storage address set in the RAM 39, respectively, trip mileage data and total mileage data are formed.

The data at the engine speed storage address, the traveling speed data, the trip traveling distance data, and the total traveling distance data are converted into data in rpm units, Km/h units, Km units, and Km units, respectively, by the conversion program. converted.

The above conversion data are each converted into display segment data.

In FIG. 6, the following peripheral devices are coupled to the microcomputer 30.

A decoder circuit 42 receives the output from the address buffer 41 via the address bus EAB.

43 receives the output signal from the decoder circuit 42 as a set instruction signal, and connects the data bus EDB.
This is a latch circuit that receives a data signal from the data buffer 40 via the latch circuit.

3 is the key switch 2 and the latch circuit 43;
This is a power supply startup circuit that receives signals output from the This power supply start-up circuit has a configuration equivalent to that of the embodiment shown in FIG. 1, for example, by removing the flip-flop circuit RSF and the delay circuit DLY.

Reference numeral 4 denotes a constant voltage circuit for receiving battery voltage through the power supply starting circuit 3 and supplying power supply voltage to each circuit shown in the figure.

44 is a drive circuit that receives the output of the latch circuit 43, and 45a and 45b are light emitting elements composed of light emitting diodes and the like.

Reference numeral 7 denotes a write voltage generating circuit which receives the output of the latch circuit 43.

Reference numeral 9 denotes a semiconductor nonvolatile device that receives the output of the write voltage generation circuit 7 at its write voltage input terminal VPP, and receives various signals supplied from the address bus EAB at its address input terminal Ai, chip selection terminal, and program terminal PGM. It's memory. As shown in the figure, the semiconductor non-volatile memory 9 has a data input/output terminal I/O connected to a data bus.
Combined with EDB.

46 is a decoder circuit that receives signals via the address bus EAB.

Latch circuits 47a to 47i each receive a signal output from the decoder circuit 46 as a set instruction signal and a signal supplied via the data bus EDB as an input data signal.

48a to 48i are drive circuits each receiving an output signal from the latch circuit.

19a to 19i are liquid crystal displays driven by the output signals of the drive circuits 48a to 48i, respectively.

In the embodiment shown in FIG. 6, when the key switch 2 is turned on, the power supply starting circuit 3 is started, and the constant voltage circuit 4 outputs the power supply voltage. As a result, each of the illustrated circuits including the microcomputer 30 becomes operational.

The on state of the key switch 2 is detected by the power control program of the microcomputer 30.

By the above control program, the power supply starting circuit 3
Data is set in the latch circuit 43 such that the line _l1 coupled to the latch becomes, for example, a low level.

When the power supply control program detects that the key switch is turned on, an initial state setting program in the microcomputer 30 is activated.

As a result, the total mileage data of the car stored in the semiconductor non-volatile memory 9 is transferred to the data bus.
EDB, data buffer 40 and data bus IDB
is written into a predetermined address of the RAM 39 via the . Further, initial data such as 0 is written to another predetermined address of the RAM 36.

After the above initial state set program is executed, various programs as mentioned above are executed,
Also, a program for writing the segment data, display data, etc. into the latch circuits 43 and 47a and 47b is executed.

As a result, the display devices 19a to 19i display information such as the vehicle's traveling speed, trip distance or total travel distance, engine coolant temperature, engine speed, etc. in an analog pattern such as a bar graph pattern or an Arabic numeral pattern. displayed as a digital pattern.

If the engine is abnormally overheated or out of fuel, line l ₂
By setting data that makes the signals _{1 through} 13 at a high level, for example, in the latch circuit 43, an image is displayed by the light emitting elements 45a through 45b.

When the key switch 2 is cut off, the cut-off state is detected by the power supply control program. This starts the data writing program. By the above program, data that causes the line _l4 to be at a high level is set in the register 43, and a write voltage of +25 volts is output from the write voltage generating circuit 7.

The total mileage data is read from a predetermined address in the RAM 39 and supplied to the data input/output terminal I/O of the semiconductor nonvolatile memory 9 via the data bus ID, data buffer 40, and data bus EDB.

A predetermined address signal, a chip selection signal, and a program signal are supplied from the control circuit 36 to the semiconductor nonvolatile memory 9 via the address bus IAB, address buffer 41, and address bus EAB.

As a result, the semiconductor nonvolatile memory 9 has:
The updated total mileage data will be written.

After the execution of the data writing program is completed, the power supply control program causes the latch circuit 43 to receive data that causes the line _l1 to go high.
is set to

As a result, the power supply starting circuit 3 stops supplying power to each of the illustrated circuits.

Note that in FIG. 6, _K3 is a switch that is placed on an instruction panel of an automobile. The switch _K3 can be used to instruct selection of display data.

According to FIG. 6 above, most of the vehicle condition monitoring device can be implemented as an electronic circuit.

The configuration or operation of the embodiment shown in FIG. 6 can be modified or improved.

For example, the reference data used when converting the data output from the sensor circuits S ₁ to S ₄ as described above is written using a switch similar to switch K ₃ instead of being written in the ROM 38 in advance. It may also be written in the semiconductor nonvolatile memory 9. In this case, since the reference data can be easily converted, sensor circuits of various different configurations can be used. Therefore, the circuit device shown in FIG. 6 can be commonly used in automobiles with various configurations. Also, similar to the above, it is possible to make corrections to output more accurate data.

In the semiconductor non-volatile memory 9, trip mileage data and control data indicating that a trip mileage data creation instruction is in progress may be further written in response to an instruction from a switch such as switch _K3 . . In this case, unlike the embodiment shown in FIG. 1, the trip distance data is displayed within the range instructed by the operator such as the driver, regardless of whether the key switch 2 is repeatedly turned on or off. You will be able to do this.

In the semiconductor non-volatile memory 9, it is also possible to write monitoring data, such as mileage data, which is taken into account for inspection and maintenance of the automobile, by using a switch such as the switch _K3 . be. In this case, by writing the desired monitoring program into the ROM38,
It is possible to display a future maintenance period or a warning that the maintenance period has come.

As a vehicle monitoring device, the analog multiplexer 31 of FIG. 6 may be supplied with battery voltage via the power start detection circuit 3 and a step-down circuit such as a resistive voltage divider. In this case, by preparing a battery voltage detection program, it becomes possible to warn of an abnormal drop in battery voltage.

The invention is not limited to the examples.

For example, the electrically erasable semiconductor non-volatile memory, EAROM, as mentioned above.
(Electrical Programmable Read Only
Memory) or EEROM (Electrical
Erasable Read Only Memory)
FAMOS (Floating Gate Avalanche Injection)
EPROM (Electrical
Programmable Read Only Memory) can be used. In this case, the data in memory is
As is known, it is erased by irradiation with light such as ultraviolet light. The memory will then be coupled with a suitable data erasing light source controlled by a key switch.

Additionally, non-volatile memory such as fuse ROM can be used if desired.

The rotation sensor may be changed to various configurations such as a configuration that uses an electric coil or a configuration that utilizes changes in capacitance instead of the configuration that uses a reed switch as described above.

[Brief explanation of the drawing]

FIG. 1 is a circuit diagram of one embodiment of the present invention, and FIG.
4 and 5 are circuit diagrams of other embodiments, and FIG. 6 is a circuit diagram of still another embodiment. 1...Battery, 2...Key switch, 3...
Power supply starting circuit, 4... Constant voltage circuit, 5... Key switch on detection circuit, 6... Key switch cutoff detection circuit, 7... Write voltage generation circuit, 8... Semiconductor nonvolatile memory, 12... Rotation sensor.

Claims (1)

[Claims] 1. A control unit including an ALU, an instruction decoder, a program counter, and a stack pointer, a ROM for storing programs, and a RAM for storing data.
A data processing device comprising: an input unit receiving signals from a sensor coupled to the vehicle and key switch on/off information; a latch circuit; and an electrically erasable and writable semiconductor non-volatile memory, the data processing device comprising: The control section, the ROM, the RAM, the input section, the latch circuit, and the semiconductor nonvolatile memory are connected by a data bus, and the ROM, the RAM, and the semiconductor nonvolatile memory are connected to each other by a data bus. accessed by the address bus, the control section takes in a signal from the input section that is the basis of mileage data from the sensor based on a program stored in the ROM, and converts it into total mileage data; The result is the above RAM
Based on the program stored in the ROM, the control section detects the shutoff of the key switch from the data of the input section, and stores the total mileage information in the RAM in the non-volatile memory. The program stored in the ROM is configured to stop supplying power to the data processing device by transmitting the data from the latch circuit to the power supply control circuit. The data processing device is characterized in that the control section detects turning on of a key switch and causes the total mileage information in the nonvolatile memory to be written into the RAM. 2. The data processing device according to claim 1 further includes an analog multiplexer receiving signals from a plurality of analog sensors, an A/D conversion circuit, and a register, the register being connected to the data bus, Based on the program stored in the ROM, the control unit takes in a signal from the analog multiplexer that is the basis of the engine cooling water temperature data from the first analog sensor, and
The D conversion circuit converts it into a digital signal, converts it into engine cooling water temperature data based on reference information, and stores the result in the RAM, and the control section executes the program stored in the ROM. Based on the reference information, a signal that is the basis of the remaining fuel amount data from the second analog sensor is taken in from the analog multiplexer, converted into a digital signal by the A/D conversion circuit, and converted into remaining fuel amount data based on the reference information. and the result above
A data processing device characterized in that data is stored in RAM.