JPH08194646A - Data writing method for microcomputer type controller and controller therefor - Google Patents

Abstract

PURPOSE: To reduce the possibility of data destruction in a protect area by manually setting a protect terminal in an active state when writing data from a CPU to the protect area. CONSTITUTION: An E<2> PROM 1 to which a CPU 20 is connected through an address bus 31 and a data bus 22 is provided with a protect area 10 and a non-protect area 11, and the operating signal of a manual switch 13 is impressed to a protect terminal 12 of the E<2> PROM 1. Further, the output part of the manual switch 13 is connected to an input port 23. Only when the protect terminal 12 is set in the active state, the write of data from the CPU 20 to the protect area 10 is allowed. When writing data to the protect area 10 in this case, the protect terminal 12 is manually set in the active state. Thus, the data can be written in the protect area of the E<2> PROM only under the management of an equipment operator, etc.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for writing data in a microcomputer type control device, and more particularly to a method for writing data in which the data can be held without fail even when the microcomputer runs away. It can be applied to various electric devices such as rice cookers and air conditioners.

[0002]

2. Description of the Related Art Many electric devices such as rice cookers and air conditioners are controlled by a microcomputer type control device. As the control device, an electrically erasable / writable read only memory (hereinafter, "E ² PROM" is described in this section)), which stores important data to prevent it from being lost in the event of a power failure.

FIG. 7 exemplifies the basic configuration of this type of control device. The central processing unit (hereinafter referred to as "CPU") (20) has a random access memory (hereinafter referred to as "RAM").
Enter. ) (21), read only memory (hereinafter,
Write as "ROM". ) (22), E ² PROM (1), and I / O ports (23) and (24) are connected via the address bus (31), etc., and the input port (23) has a sensor (27) and switch
(28) etc. are connected.

E ² incorporated in the illustrated conventional controller
PROM (1) is protected area (10) and non-protected area
When data is written to the protected area (10), a signal is applied to the protect terminal (12) to activate it, and in this state, the address of the protected area (10) and the data to be written to it are addressed. Output from the CPU (20) to the bus (31) and the data bus (32).

In this device, the data stored in the protect area (10) is thickened because the data cannot be written in the protect area (10) unless the protect terminal (12) is activated. Improves reliability. However, in the above conventional one, the E ² PROM
Since the protect terminal (12) of (1) is controlled by the CPU (20), when the CPU (20) runs away, the protect terminal (1)
There is a concern that 2) will become active, and if a write command to the protected area (10) is accidentally executed in this state, important data in the protected area (10) will be destroyed. For this reason, there is a problem that the reliability of the data in the protected area (10) is still insufficient in the above-mentioned conventional one in which the protect terminal (12) is controlled by the CPU (20).

The present invention has been made in view of the above points, and "writing of data from the CPU (20) to the protected area (10) is permitted only when the protect terminal (12) is activated. Data writing method of microcomputer type control device having E ² PROM (1) ”
The problem is to prevent the protect terminal (12) from becoming active when the CPU (20) runs out of control, thereby further reducing the possibility of data corruption in the protect area (10). And

[0007]

[Technical Means] The technical means of the present invention for solving the above-mentioned problem is that "when the data is written in the protect area (10), the protect terminal (12) is manually activated." is there.

[0008]

The above technical means operates as follows. E ² PR unless the protect terminal (12) is activated manually
Since it is not possible to write data to the protected area (10) of the OM (1), it is possible to write data to the protected area (10) only under the control of the equipment operator or the like.

[0009]

[Effect] The present invention has the following unique effects. Since it is possible to write data to the protected area (10) of the E ² PROM (1) only under the control of the equipment operator, etc., a data write command to the protected area (10) above due to a runaway CPU (20). Even if the above is executed, it is possible to further reduce the risk that the data is not written and the data is destroyed.

[0010]

EXAMPLES Next, examples in which the above-described present invention is applied to a rice cooker will be described. The rice cooker switch (61) and the reserved rice cooker switch (62) are provided on the operation part (6) formed on the upper part of the appliance body (5).
By operating (62), it is possible to perform so-called reserved rice in which the rice cooking operation is completed at an arbitrarily set reserved time.
Also, near the reservation rice cooking switch (62), there are time setting buttons (63) (63) for setting the reservation time, and the reservation set by the time setting buttons (63) (63) The time is displayed on the display (64) near the operation unit (6).

As shown in FIG. 2, the operating portion (6) is constructed such that a decorative sheet (55) is fitted and attached to a concave portion (54) formed in a casing (53) of an instrument body (5). The operation parts of the time setting buttons (63) and (63) are exposed to the outside through the through holes (56) formed in the seat (55). Then, press the time setting button (6
3) A manual switch (13) is arranged in the vicinity of (63), and its operating shaft (130) corresponds to a through hole (57) formed in the casing (53). The operation shaft (130) is hidden by the decorative sheet (55), so that the manual switch (13) cannot be operated in the completed state of the device.

As shown in FIG. 4, the output port (24) of the microcomputer (M) for controlling the rice cooker has a pot (70).
A valve device (72) for controlling the gas supply amount to the heating gas burner (71) and an ignition device (7) for igniting the gas burner (71).
3) is connected. In addition, the input port (23), the output of the flame detector (74) that detects the combustion state of the gas burner (71), the regular rice cooker switch (61) and the reserved rice cooker switch provided in the operation unit (6). (62) output, and the time setting button (6
3) The output of the memory (66) that stores the reserved time set in (63) is applied. The reserved time stored in the memory (66) is displayed on the display (64).

The E ² PROM (1) connected to the CPU (20) via the address bus (31) and the data bus (32) has a protected area (10) and a non-protected area as in the conventional ones. (1
1) and protect terminal (1) of the E ² PROM (1)
The operation signal of the manual switch (13) is applied to 2), and the output part of the manual switch (13) is connected to the input port (23). Also, the manual switch
A power supply voltage is applied to (13), and the manual switch (13) is grounded via a fixed resistor (131).

A control program having the contents shown in the flowchart of FIG. 3 is stored in the ROM (22), and the operation of the rice cooker according to the embodiment of the present invention will be described below with reference to FIG. With this product, important data is stored in the protected area (10) of the E ² PROM (1) before attaching the decorative sheet (55) of the operation part (6) during the assembly work of the rice cooker. There is. still,
As the important data, there is a valve opening degree of the valve device (72) that must be maintained in order to make the gas burner (71) the reference heating power, and since this value is slightly different for each rice cooker to be assembled, Set for each rice cooker.

Now, the operation shaft (130) exposed from the through hole (57) in a state where the decorative sheet (55) is not attached is pushed in by a work tool (not shown), whereby the manual switch (13) is turned on.
When power is supplied to the rice cooker in the N state, the program stored in the ROM (22) is executed, and first, the step (8
0) checks the status of the manual switch (13). When the manual switch (13) is operated "ON", the variable I is set to "0" in the step (81), and the data stored in the memory (66) is stored in the table (MI) (E ² Store in the protected area (10) of PROM (1) (step
(82)). Then, in step (83), the variable I is incremented by "1", and then in step (84) it is determined whether or not the variable I has reached the number K of stored data. The number of stored data K
Is the number of important data to be stored in the protected area (10) of the E ² PROM (1).

If the variable I is less than the stored data number K, the process waits until the reserved rice cooking switch (62) is turned on in step (85). Then, during this waiting, the worker sets the data to be set next with the time setting buttons (63) (63) in the memory (66).
Then, switch on the reserved rice cooking switch (62). Then, the control operation is returned to the step (82), and the memory is
The new data stored in (66) is written in the table (MI) secured in the protected area (10) of the E ² PROM (1).

In this way, important data is written in the table (MI) secured in the protected area (10) until the value of the variable I matches the stored data number K, and then the steps (84) to (86). ) (88), and the operation of the reserved rice cooking switch (62) and the normal rice cooking switch (61) is monitored. When the work of setting the above data is completed, the operation unit (6)
The decorative sheet (55) is attached at a predetermined position to complete the rice cooker assembling work.

Next, the actual rice cooking operation will be described.
When the purchaser of the appliance connects the power plug (not shown) to the outlet and turns on the reserved rice cooking switch (62), this is shown in FIG.
The rice cooking operation is started by judging the reservation time set in the memory (66), which is determined in step (86) of step (87) (8).
9)), after the rice cooking operation is completed, the heat retaining operation is executed in step (90).

On the other hand, when the normal rice cooking switch (61) is turned on, the control operation shifts from step (88) to step (89),
Immediately, the rice cooking operation and the subsequent heat retention operation are executed. In the second embodiment shown in FIG. 5, a connector (15) is inserted between the protect terminal (12) of the E ² PROM (1) and the power supply V, and the connection terminal ( 150) (151) short-circuit tool (A)
It is a short circuit. In this one,
When assembling or inspecting equipment, use the above-mentioned shorting tool (A) to
0) (151) is short-circuited to protect the E ² PROM (1) protect terminal (1
When 2) is activated and power is supplied to the appliance in this state, data is written to the protected area (10) of E ² PROM (1) according to the output of the tester (B) that inspects the electric circuit of the rice cooker. Or this can be modified. For example, when checking the offset value of the comparator (79) that judges the output of the flame detector (74) (which monitors the combustion state of the gas burner (71)) with the tester (B),
If the output of (B) is connected to the input port (23) of the microcomputer (M), the offset value detected by the tester (B) will be read into the microcomputer (M), and the ignition detection voltage etc. will be read. It is corrected and programmed so that it is stored in the protected area (10) of the E ² PROM (1).

In the second embodiment, the connection terminals (150) (151) of the connector (15) are short-circuited by the specially prepared short-circuit tool (A), but the tester (B) leads the lead wire. It is also possible to draw out and provide a test connector at the tip thereof so that the protect terminal (12) becomes active when the test connector is connected to the connector (15).
Further, in each of the above-described embodiments, the case where the present invention is applied to the rice cooker has been described as an example, but it goes without saying that the present invention can be used as a control device for various devices such as an air conditioner and a water heater.

The third embodiment shown in FIG. 6 is a CPU (20) and a RAM.
(21), ROM (22) and other built-in one-chip microcomputer (M) with E ² PROM (1) externally attached. E ² PROM (1)
Data input line (36), data output line (37),
Also, the protection monitoring line (39) and the like are connected to the serial communication port of the microcomputer (M). Also, the clock for synchronizing the communication operation is the microcomputer via the clock line (38).
Together is adapted to be sent to the E ² PROM (1) from (M), the manual switch is protected terminal (12) of the E ² PROM (1)
The operation signal of (13) is applied. Furthermore,
The microcomputer (M) includes the valve device (72) and the ignition device (73) described above.
And a load drive circuit (48) such as a circuit (for example, a circuit that controls opening / closing of a solenoid valve that constitutes the valve device (72)).

In this case, the data stored in the protected area (10) and the non-protected area (11) of the E ² PROM (1) is read by the microcomputer (M) via the data input line (36). Further, the microcomputer (M) monitors the ON operation of the manual switch (13) with the protection monitor line (39), and the manual switch (13)
When is turned on, the data output line (37) outputs E ² PROM
Write important data to the protected area (10) in (1).

[Brief description of drawings]

FIG. 1 is a front view of a rice cooker according to an embodiment of the present invention.

[Fig. 2] Enlarged cross-sectional view near the operation part (6)

FIG. 3 is a flowchart illustrating a control program.

FIG. 4 is a control circuit diagram

FIG. 5 is an explanatory view of a second embodiment.

FIG. 6 is an explanatory diagram of the third embodiment.

FIG. 7 is an explanatory diagram of a conventional example.

[Explanation of symbols]

(12) ・ ・ ・ Protect terminal (20) ・ ・ ・ CPU (10) ・ ・ ・ Protected area (11) ・ ・ ・ Unprotected area (1) ・ ・ ・ E ² PROM

Claims (3)

[Claims] 1. A microcomputer type control device having an E ² PROM (1) which allows writing of data from a CPU (20) to a protected area (10) only when a protect terminal (12) is activated. The data writing method of the microcomputer type control device in which the protect terminal (12) is manually activated when writing the data to the protected area (10). ^2. A microcomputer type control device having an E ² PROM (1) which allows writing of data from the CPU (20) to the protected area (10) only when the protect terminal (12) is activated. At the protect terminal
A microcomputer type control device in which a manual switch (13) is connected to (12) and the protect terminal (12) is activated only when the manual switch is operated. 3. A microcomputer type control device having an E ² PROM (1) which allows writing of data from the CPU (20) to the protected area (10) only when the protect terminal (12) is in an active state. At the protect terminal
Connection terminal (151) connected to (12) and connection terminal connected to the power supply
A microcomputer type control device provided with (150) so that the protect terminal (12) becomes active only when the pair of connection terminals (150) (151) are short-circuited.