JPS63156217A - Microcomputer reset device - Google Patents

Abstract

PURPOSE:To prevent abnormal data for voltage reduction from being taken in by using the time difference of rise and fall among plural power sources to reset one microcomputer by another computer. CONSTITUTION:In accordance with a program by which a power source B of the CP 1 rises in a short time by power-on and the CP 1 starts the software processing earlier than CPs 2 and 3 and continues to send a reset signal to CPs 2 and 3 till the rise of a power source A and releases reset of CPs 2 and 3 at the time of rising the power source, CPs 2 and 3 start operations when the power source A rises in a long time. The voltage of the power source B monitors the CP 2 to send a signal to the reset terminal of the CP 3, and the CP 1 stops the operation and the CP 3 is reset when the power source B falls at the time of power-off.

Description

[Detailed Description of the Invention] Industrial Field of Application The present invention is applicable to microcontrollers and computers that operate when a device has a plurality of microcombiners or computers (hereinafter referred to as microcontrollers), and is used when the power supply voltage drops or when the power is turned on or turned off. The present invention relates to a reset device.

Conventional microcontrollers operate only when the power supply voltage exceeds a certain specified voltage, and stop operating when the voltage falls below the specified voltage.

Conventionally, in devices with multiple microcontrollers, when the power is turned on or off, a capacitor or the like is inserted into the power supply section, and the operation is started or stopped after a certain amount of time compared to the sensor and other sections. Was. Furthermore, the instantaneous drop in the power supply voltage is compensated for by the discharge effect of the capacitor. This prevents the microcontroller from receiving abnormal data.

Problems to be Solved by the Invention However, in the above-described configuration, there is a slight time lag in each of the plurality of microcomputers from the time the power is turned on to the start of program production due to variations in the wiring of the power supply circuit and the characteristics of each microcomputer. Therefore, when the power is turned on, a phenomenon occurs in which one microcontroller is operating but the other microcontroller is not, and as a result, the microcontroller that operates first receives the data that should have come from the other microcontroller and is affected by noise, etc. This could result in an abnormal signal being taken in, resulting in malfunction. As a result, checking of the captured data had to be implemented in the form of software for each microcontroller, which increased the amount of software. Also, when the power is turned off, because a capacitor is inserted into the power supply part, some of the sensors stop functioning first, and this causes the microcontroller to receive an abnormal signal that is different from the signal originally received from the sensor. ,
This also caused a malfunction. For this as well, software for each microcomputer must be prepared, and the instantaneous drop in power supply voltage that led to an increase in the amount of software is the same as when the power was cut off.

In view of the above problems, the present invention provides a microcomputer reset device that prevents the microcomputer from importing abnormal data.

Means for Solving the Problems In order to solve the above problems, the microcomputer reset device of the present invention includes a plurality of microcomputers,
It is equipped with a plurality of power supplies each having a different rise time when the power is turned on and a fall time when the power is turned OFF. This system has a configuration in which one of the microcomputers detects the detection, and the operation of this microcomputer limits the operation of other microcomputers.

Operation The present invention utilizes the difference in the temporal characteristics of two power supplies with different rise and fall times to manually transmit a signal from one microcomputer to the reset terminal of another microcomputer, using the above-described configuration. Reset program operation. This prevents other microcontrollers from importing abnormal data, and the only software response to abnormal data in the microcontroller is the microcontroller that issues a reset signal, reducing the amount of software required.1. This also prevents malfunctions.

Embodiment FIG. 1 is a block circuit diagram showing an embodiment of a microcomputer reset device according to the present invention. In Fig. 1, 1 is a microcomputer that detects when the power is turned on, 2 is a microcomputer that detects when the power is turned off or drops, 3 is another microcomputer, and 4 is a microcomputer that takes a long time to rise to the specified voltage when the power is turned on. 6 is a power supply with a long fall time that drops to a specified voltage when the power is turned off (hereinafter referred to as power supply A), and 6 is a power supply with a short rise time and short fall time (hereinafter referred to as power supply B).

Further, 6 is a part of other sensors. The operation will be explained below.

First, when you turn on the power, power supply B starts up. This power supply B
is a power source for microcomputer 1, and software processing of microcomputer 1 starts operating earlier than other microcomputers 2 and 3. A signal is sent from microcomputer 1 to the reset terminals of microcomputers 2 and 3, and at the same time, the voltage of power supply A is monitored using an analog/digital input terminal (hereinafter referred to as A/D input terminal). Further, power supply A is the power supply for the second microcomputer. With the above configuration, microcomputer 1, which starts operating first, sends a reset signal to microcomputers 2 and 3 when power supply A is turned on.

Since it is programmed to release the reset of microcontrollers 2 and 3 only when power supply A is turned on, microcontrollers 1, 2, and 3 start operating only after power supply A is turned on, so no abnormal signals are received by these microcontrollers. . When the power is turned off, power supply B is first turned off. This power supply B
The microcomputer 2 monitors the voltage using the A/D input terminal.

Further, a signal is sent from the microcomputer 2 to the reset terminal of the microcomputer 3. Therefore, when the power supply B goes down, the microcomputer 1 stops operating and the microcomputer 3 is reset. Therefore, the microcomputers 1 and 3 do not receive any abnormal signals. In addition, the other sensors 6 are driven by power supplies A and B, so that they start up first when the power is turned on.

When the power is turned off or the power drops, it operates until the end, so it does not issue any abnormal signals. Furthermore, with the above configuration, only the microcomputer 1 needs to take care of the software when the power is turned on, and only the microcomputer 2 needs to take care of it when the power goes down, so the amount of software can be reduced.

Father distribution power supply A has a long rise time and a long fall time, and power supply B has a short rise time and a short fall time, but instead, power supply A has a long rise time and a short fall time, and power supply A has a short rise time. Let B be the power supply with the shortest fall time.

Using the power supply of microcontroller 1, 2.3 as power supply B, microcontroller 1
By monitoring the power supply A at the microcomputer 1, a similar effect can be obtained in which only the microcomputer 1 can detect both the rise and fall of the power supply and reset the other microcomputers.

Effects of the Invention As detailed above, the present invention utilizes the time difference between the rise and fall of the power supply to apply and release the reset, so it is not affected by variations in the elements of the microcontroller, and the software Correspondence is also largely eliminated since the minimum required is one each when turning on the power and when turning off the power. In addition, some of the other sensors start up before other microcomputers when the power is turned on, and fall off after the other microcomputers when the power is turned off, so they do not output abnormal data. Therefore, when a plurality of microcomputers operate, the situation in which the microcomputers take in abnormal data when the power is turned on and off, or when the voltage drops is eliminated.

[Brief explanation of the drawing]

The figure is a block circuit diagram of a microcomputer reset device in one embodiment of the present invention. 1.2,3... microcomputer, 4...
...Power supply A, s...Power supply B, e...
·sensor.

Claims (1)

[Claims] It is equipped with a plurality of microcomputers and a plurality of power supplies each having a different rise time when the power is turned on and a fall time when the power is turned off. A microcomputer reset device characterized in that one of the microcomputers detects turning on and turning off, and the operation of the other microcomputers is restricted by the operation of this microcomputer.