JPH05341884A - Controller for electronic equipment - Google Patents

Abstract

PURPOSE:To prevent erroneous control data from being written in a nonvolatile memory, and to prevent important data from erroneously erased, due to the unprepared reset of a microcomputer. CONSTITUTION:This device is equipped with a microcomputer 30 which controls an operation mode, and a nonvolatile memory 31 in which control data are written by a communication with the microcomputer. Also, the device is equipped with a reset control circuit 40 constituted of a single OR gate 400 which controls the reset of the microcomputer, and the reset of the microcomputer can be attained only when the communication between the microcomputer and the nonvolatile memory is not operated.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a control device for electronic equipment equipped with a microcomputer for controlling operation.

[0002]

2. Description of the Related Art Recent electronic devices are equipped with microcomputers for various controls. Then, the information for the control is stored in advance in a non-volatile memory such as an EEPROM made non-volatile by a backup power supply, and communication is performed between the non-volatile memory and the microcomputer. , Read information necessary for control and perform predetermined control. Further, in some cases, information for control may be appropriately written in the non-volatile memory by a user operation.

For example, in a television receiver or a VTR with a built-in tuner, a microcomputer for controlling the operation mode accesses the nonvolatile memory to read the preset data stored therein in accordance with a direct or remote tuning operation. A tuning signal corresponding to a specific channel is formed. Then, this tuning signal is supplied to the tuner, and the television broadcast of the desired channel is received.

As described above, the preset data of each channel is written in the non-volatile memory in the manufacturing process of the television receiver and the like. Further, the preset data in the nonvolatile memory can be rewritten via the microcomputer by the user operating a predetermined key. In either case, serial communication is performed between the nonvolatile memory and the microcomputer.

Further, the data of the receiving channel (last channel) immediately before the power of the television receiver is turned off is written in the non-volatile memory, and the power is turned off based on the data of the last channel at the next power-on. A television broadcast on the same channel as before is received. Further, in the case of the VTR, changeover switch control for recording / reproduction is written in the memory.

[0006]

In the conventional television receiver and tuner VTR as described above, the microcomputer for controlling the operation mode is out of the predetermined sequence due to, for example, external noise or erroneous operation. Abnormal operation, that is, runaway may occur.
When the microcomputer runs out of control, generally, the runaway of the microcomputer can be stopped only by turning off the power of the microcomputer or resetting the microcomputer.

However, in the conventional television receiver as described above, since the reset circuit is directly connected to the reset terminal of the microcomputer,
If the microcomputer is carelessly reset while communication is being performed between the microcomputer and the non-volatile memory, erroneous writing or erroneous reading will occur. Therefore, based on this incorrect control data,
After the reset, there is a problem that the electronic device operates differently from the expected operation, and in the worst case, the important information stored at the time of factory shipment is erased or destroyed.

An object of the present invention is to provide a control device for an electronic device which solves the above problems and can prevent accidental reset of a microcomputer.

[0009]

In order to solve the above-mentioned problems, a control device for an electronic device according to the present invention relates to a microcomputer 30 for controlling the electronic device, and a microcomputer 30 for controlling the electronic device when the reference numerals of the embodiments described later correspond to each other. Computer 3
In the control device of the electronic device including the non-volatile memory 31 that communicates with 0 to write and read data for control, the reset control means 40 that controls the reset of the microcomputer 30 is provided, and the non-volatile memory 31 only when the communication between the microcomputer 31 and the microcomputer 30 is not performed.
It is possible to reset 0.

[0010]

According to the present invention having the above-described structure, resetting of the microcomputer is prohibited when communication is being performed between the microcomputer and the nonvolatile memory.

[0011]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment in which a control device for electronic equipment according to the present invention is applied to a VTR with a tuner will be described below with reference to FIG.
2 and FIG. 2. FIG. 2 shows the entire structure of an embodiment of the present invention, and FIG. 1 shows the structure of the main part.
In FIG. 2, reference numeral 10 denotes a television broadcast receiving unit, which supplies a high frequency signal of the television broadcast band received by the antenna 1 to the tuner 11, selects a signal of a desired channel, and converts it into an intermediate frequency signal. .. This intermediate frequency signal is amplified and detected in the intermediate frequency / detection circuit 12 to obtain a video signal Sv and an audio signal Sa.

Reference numeral 20 denotes a VTR main body, which is a broadcast receiving unit 1.
The video signal Sv and the audio signal Sa from 0 are recorded in the recording circuit 21.
Is supplied to the video output terminal 2v and the audio output terminal 2a. The recording circuit 21 and the reproduction circuit 22 are the recording / reproduction changeover switch circuit 2
3 through the magnetic heads 25A, 25A of the mechanical deck 24.
Connected to B. A rotary drum 26 on which both heads 25A and 25B are mounted is driven by a motor 27.

Reference numeral 30 is a microcomputer as a system control circuit, 31 is an EEPROM, and 32 is a microcomputer for controlling the VTR main body 20.
The microcomputer 30 has a tuning operation key and a VT.
Key operation group 33 such as R mode selection key and travel control key
Are connected. The EEPROM 31 is non-volatile with a backup power supply 34 connected.

The microcomputer 30 is an EEPRO.
The tuning of the tuner 11 is controlled based on the preset channel data stored in M31. Further, when the VTR main body 20 is brought into a recording or reproducing state, the microcomputer 30 sends the command to the microcomputer 3
2, and necessary information such as VTR recording / reproducing switching information read by communication with the EEPROM 31 is transferred to the microcomputer 32. The microcomputer 32 controls switching of the switch circuit 23 and also controls switching circuits in the recording circuit 21 and the reproduction circuit 22.

In this embodiment, the microcomputer 3
In order to control the reset of 0, the reset control circuit 40
Is provided, and the reset switch 41 and the microcomputer 30 are connected via the reset control circuit 40. 30 rs is a reset terminal of the microcomputer 30. In this example, the reset terminal 30r
When s is set to "L", the microcomputer 30 is reset.

As shown in FIG. 1, the reset control circuit 40 of this embodiment comprises a single OR gate 400.
One of the input terminals 40a of the OR gate 400 has an EEP
A chip select signal Scs from the microcomputer 30 is supplied in common with the ROM 31. The other input terminal 40b of the OR gate 400 is connected to the DC power supply Vcc via the resistor R and is grounded via the reset switch 41. And OR gate 400
The output terminal of is connected to the reset terminal 30rs of the microcomputer 30. In this example, only when the chip select signal Scs from the microcomputer 30 is "H", the microcomputer 30 and the EEPROM 31 are
It is possible to communicate with. When the chip select signal Scs is "H", the microcomputer 30 outputs the serial clock Sck and the output data Sdo.
Is supplied to the EEPROM 31 to write data, or the data Sdi read from the EEPROM 31 is supplied to the microcomputer 30.

Next, the operation of the reset control circuit of the embodiment shown in FIG. 1 will be described. In this embodiment, the chip select signal Scs is used to prohibit the careless reset of the microcomputer 30.

In the OFF state where the reset switch 41 is not pressed, the other input terminal 40b of the OR gate 40 is held at "H", and the reset terminal 30 of the microcomputer 30 is maintained regardless of the chip select signal Scs.
rs also becomes “H”, and no reset is applied.

When the reset switch 41 is pressed and turned on, the input terminal 40b of the OR gate 40 becomes "L". In this state, the chip select signal Scs
Is "H", the microcomputer 30 and the EEPROM
When communicating with the microcomputer 31, the microcomputer 3
The reset terminal 30rs of 0 also becomes "H", and the microcomputer 30 is not reset.

The chip select signal Scs is "L".
Then, when communication is not performed between the microcomputer 30 and the EEPROM 31, the reset terminal 30
rs also becomes "L", and the microcomputer 30 is reset.

That is, in this embodiment, the reset switch 41 is enabled only when the microcomputer 30 and the EEPROM 31 are not communicating with each other. When the EEPROM 31 and the microcomputer 30 are communicating, the OR gate 40
This prohibits the reset of the microcomputer 30.

Therefore, in this embodiment, when the microcomputer 30 goes out of control, the reset switch 41
Even if the button is operated, the microcomputer 30 is not reset until the communication with the EEPROM 31 is completed, and, for example, erroneous preset channel data is stored in the EEPROM.
It is not written in the ROM 31, and the stored data is not erased by erroneous reading.

Although the OR gate is used as the reset control circuit in the above-mentioned embodiments, an appropriate logic circuit can be used according to the polarity of the chip select signal and the required reset pulse.

The embodiments in which the present invention is applied to a VTR with a built-in tuner have been described above, but the present invention can be similarly applied to preset reception of a television receiver or an AM / FM radio receiver.

Further, in a telephone or a facsimile, a predetermined key operation is performed to write in a nonvolatile memory a preset number, for example, a 10-digit number of a specific receiver having a high communication frequency, and the key is set once or several times. A so-called one-touch dial or abbreviated dial is widely used in which preset data in a memory is read out by operation to connect to a specific receiver. Even when the preset data such as the one-touch dial is written in the nonvolatile memory, by applying the present invention, the careless reset of the microcomputer is prohibited, which is caused by the reset, like the above-described embodiment. Wrong preset data will not be written in the nonvolatile memory and important data will not be accidentally erased.

[0026]

As described above, according to the present invention, a control device for electronic equipment including a microcomputer for controlling an operation mode and a non-volatile memory in which control data is written by communication with the microcomputer. In the above, a reset control circuit for controlling the reset of the microcomputer is provided, and the microcomputer can be reset only when communication with the nonvolatile memory is not performed. Therefore, it is possible to prevent erroneous control data from being written in the nonvolatile memory and important data from being destroyed.

[Brief description of drawings]

FIG. 1 is a block diagram showing a configuration of a main part of an embodiment of a control device for an electronic device according to the present invention.

FIG. 2 is a block diagram showing the overall configuration of an embodiment of the present invention.

[Explanation of symbols]

 11 tuner 20 VTR main body 30 microcomputer 31 non-volatile memory (EEPROM) 40 reset control circuit 41 reset switch

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁵ Identification code Internal reference number FI technical display location G11C 19/00 H 6741-5L

Claims (4)

[Claims] 1. A control device for an electronic device, comprising: a microcomputer for controlling an electronic device; and a non-volatile memory for communicating with the microcomputer and for writing and reading data for control. And a reset control means for controlling the reset of the microcomputer, the control device of the electronic device capable of resetting the microcomputer only when communication is not performed between the nonvolatile memory and the microcomputer. .. 2. The control device for an electronic device according to claim 1, wherein an EEPROM made non-volatile by a backup power supply is used as the non-volatile memory. 3. The control device for an electronic device according to claim 1, wherein the control data written in the nonvolatile memory is tuner preset channel data. 4. The control data written in the non-volatile memory is preset data, and the preset data is selectively read from the non-volatile memory by a key operation, and predetermined control is performed. The control device for an electronic device according to claim 1.