JPH0748171B2 - Control method using a microcomputer - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Use and Outline of the Invention] The present invention relates to a control method using a microcomputer, and particularly to a control method in consideration of measures against power failure, and can be used for, for example, a rice cooker.

The outline of the present invention is to reduce the discharge of a capacitor that backs up the data written in the memory of the microcomputer so as not to be lost / changed at the time of power failure, and thereby to cope with a long-term power failure. Is.

[Prior Art and Problem] For example, there is a rice cooker as a device for controlling the operation using a built-in microcomputer (hereinafter, abbreviated as a microcomputer). The rice cooker has a stored device control state when a power failure occurs. There is a device equipped with a power failure countermeasure function which allows the user to select the device control after the power failure is released.

In the appliances that have been provided with the above measures against power failure, the microcomputer for controlling the appliances is backed up by a backup power supply,
The control data indicating the control status at the time of power failure is not lost even after the power failure. In a control device such as a timer type rice cooker for business use, it is necessary to continue device control and device monitoring without interruption even when the power is cut off on holidays, etc. Will be needed.

As a control device provided with measures against the above-mentioned long-term power failure, for example, there is a control device as shown in FIG.
The microcomputer (1) incorporated in the control device is operated by the electric power supply from the power supply circuit (3) including the auxiliary power supply capacitor (81). The output of the power failure detection circuit (2) is applied to the power failure signal input port (10) of the microcomputer (1). In addition, a relatively large capacity (1 to 3F) is obtained by supplying electricity from the power supply circuit (3).
Backup capacitor (4) is charged, and the voltage across the backup capacitor (4) is applied to a random access memory (referred to as a memory group) (5) that stores necessary data. This is backed up so that the data in the memory group (5) at the time of power failure can be retained. Furthermore, the voltage across the backup capacitor (4) is applied to a clock (7) for measuring the duration of power failure.

The voltage across the backup capacitor (4) is
It is monitored by a voltage monitoring circuit (6) consisting of resistors (61), (61), a zener diode (69) and a comparator (60), and the output of the voltage monitoring circuit (6) is reset by the microcomputer (1). Applied to terminal (12).

In this case, since the memory group (5) in which the control data indicating the device control state at the time of power failure is written is backed up by the backup capacitor (4), even if a power failure occurs, the memory group ( The control data written in 5) will not be lost. Therefore, when the power outage detection circuit (2) outputs the power outage cancellation signal after the power outage ends, the stored data can be examined to determine the appliance control state at the time of the power outage. It is possible to continue the appliance control after the power outage according to the appliance control state.

In the control device described above, if a long-time power failure that exceeds the capacity of the backup capacitor (4) occurs and the necessary data written in the memory group (5) may be lost or changed, the backup capacitor ( The voltage monitoring circuit (6) detects the voltage drop of 4), the microcomputer (1) is reset by the detection signal, and the instrument is held in a stopped state. As a result, it is possible to prevent the risk that the control data in the memory group (5) changes during a long power failure and the device malfunctions after the power failure is released.

However, in the above-mentioned conventional one, the voltage of the backup capacitor (4) for backing up the memory group (5) in which the control data indicating the control state at the time of power failure has been written is set to In addition to being applied to the time measuring clock (7), the voltage of the capacitor (4) is a voltage composed of resistors (61), (61), a zener diode (69) and a comparator (60). It is applied to the monitoring circuit (6). That is, as a component operated by the electric power supplied from the single backup capacitor (4), a voltage monitoring circuit for monitoring the voltage of the backup capacitor (4) other than the memory group (5) and the clock (7). (6) exists.
The voltage monitoring circuit (6) includes resistors (61) and (61).
The voltage monitoring circuit (6) consumes a large amount of electricity stored in the backup capacitor (4) because it is composed of a plurality of elements such as a comparator and a comparator (60). There was a problem that the backup time due to 4) would be shortened.

The present invention has been made in view of the above point, and includes a "power failure detection circuit (2) for detecting the occurrence and cancellation of a power failure, and a microcomputer (1) that is charged by electricity supplied from a power supply circuit (3). A capacitor for auxiliary power supply connected to the power supply terminal (19), a backup capacitor (4) which is charged by the power supplied from the power supply circuit (3), and the power supplied from the backup capacitor (4). A memory group (5) for storing control data indicating the control status of the controlled object at the time of power failure is provided by the microcomputer (5) when there is a long power failure exceeding the backup capacity of the backup capacitor (4). 1) is held in a reset state, while the backup capacitor (4) is stopped for a short time within the backup capacity range. When the power is released, the control data stored in the memory group (5) is used to continue the subsequent control by using the control data at the time of power failure ”. By eliminating the circuit (6), the amount of electricity stored in the capacitor (4) is reduced, and
The task is to make the backup time by the backup capacitor (4) longer.

[Means] A technical means of the present invention for solving the above-mentioned problem is to provide "check data memories (51), (51), ... interspersed in the memory group (5) and set in advance. Check data (D1), (D2), ... Check data memory (51), (51) ,.
Check data writing step to write to each separately, and the above check data memory (51), (5
1) ... Read step of reading the stored data in
Further, a comparison step for individually checking the consistency between the read data and the preset check data (D1), (D2), ... Is executed in this order, and the comparison step is executed. When at least one set of two types of data to be compared do not match each other, the microcomputer (1) is reset. ”

[Operation] The above technical means operates as follows.

When the microcomputer (1) is operated, the check data is written in the memory group (5) at the initial stage of the operation or immediately after the occurrence of a power failure described later.

That is, when the check data is written in the initial stage of the operation of the microcomputer (1), the microcomputer (1) which is operated by the electricity supplied from the power supply circuit (3) executes the write step, and the memory group (5 Check data (D1), (D2) ... that are preset in the check data memories (51), (51) ..
To write. Further, when the above check data (D1), (D2) ... Is written immediately after the occurrence of a power failure, the microcomputer for auxiliary power supply that functions as the power source of the microcomputer (1) for a while immediately after the occurrence of a power failure uses the microcomputer. (1) operates, and the operating microcomputer (1) executes the writing step. Further, in the memory group (5), control data when a power failure occurs is written in the same way as the conventional one.

As a result, in the state where the power failure continues, the memory group (5) storing the control data and the check data at the time of the power failure is maintained in the state backed up by the backup capacitor (4). Then, after the power failure described later, it is determined whether or not the power failure that occurred is a power failure within the capacity of the backup capacitor (4) by the operation described later that checks whether or not the check data has been lost or changed. It is supposed to be done.

Now, when the power failure is released and the microcomputer (1) starts to operate again by the electric power supply from the power supply circuit (3), the reading step is executed when the power failure is released, and the check data memory (51), ( The data stored in 51) is read. Then, the read data and the check data (D1) and (D2) that have been set in advance to be written in the memory group (5) immediately after the occurrence of the power failure.
.. A comparison step is performed which compares whether and match with, thereby checking the consistency of both these data.

Then, the check data written in the check data memory (51), (51) immediately after the power failure occurs or before and the check data memory (51), (51) after the power failure is released.
If all the data read from
It is judged that all the data (data indicating the control state before the power failure) stored in the memory group (5) has not deteriorated, and the data in the memory group (5) indicating the control status when the power failure occurs Continues control after the power failure is released based on the control data.

On the other hand, the check data written in the memory group (5) is lost due to a long power failure that exceeds the backup capacity of the backup capacitor (4).
If there is a change, the check data read from the check data memories (51) and (51) after the power failure is released is compared with the check data written to the check data memories (51) and (51) immediately after the power failure occurs. At the same time, the two do not match. Then, the check data (D1), (D2), ... Written in the check data memories (51), (51) of the memory group (5) are altered and stored in the memory group (5) before the occurrence of a power failure. When it is determined that the control data indicating the control state of 1) is also degenerated, the microcomputer (1) is maintained in the reset state.

As described above, according to the present invention, the check data (D1), (D2), ... Written in the memory group (5) disappears or changes, and a long power failure occurs that exceeds the capacity of the backup capacitor (4). If it is determined that it is present, this can be determined by the function of the microcomputer (1), and as described above, a voltage monitoring circuit that consumes a large amount of electricity stored in the backup capacitor (4). It is not necessary to provide a special circuit like (6). Then, since a special circuit such as the voltage monitoring circuit (6) is unnecessary, the amount of electricity stored in the backup capacitor (4) consumed during a power failure can be suppressed to a small amount.

[Effect] The present invention has the following unique effects.

As described above, it is not necessary to provide the voltage monitoring circuit (6) for monitoring the voltage of the backup capacitor (4), so that the power consumption during the power failure is small, and the power consumption is reduced, the backup is performed. The time for which the capacitor (4) can hold the necessary data in the memory group (5) becomes long.
That is, it is possible to cope with a power failure for a longer time than the conventional one described above.

Further, since the check data memories (51) and (51) are scattered in the control data storage memory group (5), it is possible to judge whether the storage state of the control data stored in the memory group (5) is good or bad. It will have high reliability. That is, when the check data is intensively written in the vicinity of a specific address in the memory group (5), the write locations of the check data are partially biased. Therefore, in such a case, the storage state of the data cannot be determined for the entire memory group, and the reliability of the determination becomes low. On the other hand, according to the above technical means, since the Chuk data scattered in the memory group (5) is examined, the memory group (5) is entirely observed and the storage state of the data is good or bad. Can be judged, and the reliability of the judgment is improved.

[Embodiment] As shown in FIG. 1, in the control device embodying the present invention,
The circuit configuration is the same as that of the conventional control device described above, except that the voltage monitoring circuit (6) for monitoring the voltage across the back-up capacitor (4) is not provided. That is, the output of the power failure detection circuit (2) is applied to the power failure signal input port (10) of the microcomputer (1), and the voltage across the backup capacitor (4) is applied to the clock (7). Is being applied. The voltage across the backup capacitor (4) is also applied to the backup terminal (41) of the memory group (5). Furthermore, the power supply is required to operate the microcomputer (1) for a fixed time immediately after a power failure. The auxiliary power supply capacitor (81) of the circuit (3) is used. In addition, in the figure, the smoothing capacitor (8
2) also functions as a power source for operating the microcomputer (1) when a power failure occurs.

A power failure processing program as shown in the flowchart of FIG. 2 is written in the microcomputer (1), and the operation of the control device of the embodiment of the present invention will be described with reference to the flowchart of FIG. Note that the necessary data indicating the control status of the controlled device before the power failure occurs (for example, in the case of rice cookers, the data indicating the timer set time, whether rice porridge or normal rice is being executed, etc.) has been described above. It is stored in the memory group (5) in the same manner as the above.

． When a power failure occurs, electric power is supplied from the auxiliary power supply capacitor (81) and the smoothing capacitor (82) of the power supply circuit (3) to keep the microcomputer (1) in an operating state for a while. Then, while the microcomputer (1) is operating immediately after the occurrence of the power failure, the power failure occurrence time is read from the clock (7) by the power failure signal detected by the power failure detection circuit (2) and is read in the memory group (5). And a writing step (90) for writing the check data to be checked after the power failure is released to the check data memories (51) and (51) (memory secured at the scattered addresses) which are stored in the memory group (5). To be executed. In addition, a power failure standby process of saving necessary data in the memory group (5) is performed, and thereafter, the power failure detection circuit (2) waits for a power failure cancellation signal. (Refer to the process of FIG. 2 (a)) Then, after the occurrence of the power failure, the operation of the clock (7) is maintained by the voltage across the backup capacitor (4), and the microcomputer by the voltage of the backup capacitor (4). The memory group (5) of (1) is backed up.

． When the power failure is eventually released, the program processing shown in (b) of Fig. 2 starts, and the reading step (93) for reading the check data written in the check data memory (51), (51) immediately after the power failure occurs. It is executed and the consistency of whether the read check data is the same as the data written immediately after the power failure occurs is checked. Then, if a long power failure exceeding the capacity of the backup capacitor (4) occurs and the data in the memory group (5) is altered, the check data memory (51), (51) immediately after the power failure occurs. The check data written in the check data and the data read from the check data memories (51) and (51) after the power failure is released do not match, and in this case, the data stored in the memory group (5) for controlling the equipment is stored. It is determined that the data (data indicating the control state before the power failure, etc.) has deteriorated, and the microcomputer (1) is reset. (Refer to the process of drawing symbols (93), (94), (95)) Then, compare the check data written in the check data memories (51), (51) with the data read from the memory after the power failure is released. The procedure in the program to be executed corresponds to the comparing step described in the above-mentioned technical means section.

On the other hand, when a power failure occurs, the check data memory (51),
When the check data written in (51) and the data read from the check data memory (51) and (51) after the power failure is released are all the same (in the case of a short power failure within the capacity of the backup capacitor (4)) In this case, it is determined that the appliance control data stored in the memory group (5) (such as the data indicating the control state before the power outage) has not deteriorated. Further, in the case of this embodiment, even when it is judged that the control data stored in the memory group (5) before the power failure is not deteriorated, the power failure release time is further read from the clock (7). The power outage duration is calculated, and it is determined whether or not the power outage duration does not exceed the previously known capacity (standardized capacity) of the backup capacitor (4) (see step (95)). . If it is confirmed that the power outage is within the capacity of the capacitor (4), the control data before the power outage stored in the memory group (5) is used to save the power before the power outage occurs. After the power failure cancellation processing to return to the state of, the appliance control following the control before the occurrence of the power failure is continued (drawing code (9
See step 6)).

Thus, in the above embodiment, the memory group (5)
By checking the check data in the check data memories (51) and (51) scattered in the above after power failure is released, the processing of the microcomputer after power failure is released can be branched into normal and abnormal processing. Unlike the conventional one, the special circuit such as the power supply circuit (3) for monitoring the amount of electricity stored in the backup capacitor (4) is not required. Therefore, the amount of electricity stored in the backup capacitor (4) is not consumed by the power supply circuit (3) in the conventional one, and the backup time by the backup capacitor (4) becomes long.

In the above embodiment, the check data is written in the memory group (5) immediately after the power failure occurs, but the check data may be written in the initial stage of the operation of the microcomputer (1). In this case, the check data write operation can be performed by the electricity supplied from the power supply circuit (3).

[Brief description of drawings]

FIG. 1 is a circuit configuration diagram of an embodiment of the present invention, FIG. 2 is a flow chart explaining a control program written in a microcomputer (1), and FIG. 3 is an explanatory diagram of a conventional example, in which (2) ... … Power failure detection circuit (3) …… Power supply circuit (4) …… Backup capacitor (5) …… Memory group (51) …… Check data memory

Front page continuation (72) Inventor Osamu Hotta 4-1-2, Hirano-cho, Chuo-ku, Osaka-shi, Osaka Within Osaka Gas Co., Ltd. In Nanai Co., Ltd. (56) Reference JP-A-57-127220 (JP, A) Actually developed 62-187349 (JP, U)

Claims (1)

[Claims] 1. A power failure detection circuit (2) for detecting the occurrence and cancellation of a power failure, and an auxiliary power source that is charged by the electricity supplied from a power source circuit (3) and is connected to a power source terminal (19) of a microcomputer (1). Capacitor, a backup capacitor (4) which is also charged by the electricity supplied from the power supply circuit (3), and further controlled by electricity supplied from the backup capacitor (4) and to be controlled when a power failure occurs A memory group (5) for storing control data indicating a control state of the object is provided, and the microcomputer (1) is held in a reset state when there is a long-time power failure that exceeds the backup capacity of the backup capacitor (4). On the other hand, if the short-term power failure within the backup capacity range of the backup capacitor (4) is canceled, the memory group In the case where the control is stored in 5) and the subsequent control is continued by using the control data at the time of power outage, the check data memories (51), (51) ... scattered in the memory group (5) In addition to the above, check data (D1), (D2), ...
1), (51), ... Check data writing step for writing to each, and a read step for reading the stored data in the check data memory (51), (51) ,. And the comparison step for checking the consistency of the check data (D1), (D2), ..., which has been set in advance, with each other in this order, and as a result of executing the comparison step
A control method using a microcomputer for resetting a microcomputer (1) when at least one set of data of a kind does not match each other.