JPH05241978A - Electronics - Google Patents

Abstract

PURPOSE:To preserve data in a microcomputer for which no backup is performed when a power source is disconnected and to dispense with initialization processing when the power source is applied again in electronic equipment provided with plural microcomputers. CONSTITUTION:The data in a RAM 12 in the microcomputer 2 whose power source is not backed up is transferred to and preserved in the microcomputer 1 whose power source is backed up when the power source is disconnected. When the power source is applied again, the data is transferred from the microcomputer 1 to the microcomputer 2. In such a way, it is possible to dispense with the initialization processing when the power source is applied again.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electronic device whose operation is controlled by a plurality of microcomputers.

[0002]

2. Description of the Related Art Recent electronic devices, such as a video cassette recorder with a built-in camera, are provided with a plurality of one-chip microcomputers such as a mode controller and a mechanical controller as control means for controlling the electronic device. There is.
The mode control is a microcomputer that determines a user's key input and sets the operation of each unit according to the key input. The mechanical controller is a microcomputer that controls rotation of a drum motor and a capstan motor. The one-chip microcomputer is composed of a CPU, a memory such as a RAM, and peripheral circuits such as an I / O port.

Of these microcomputers, the mode controller controls the on / off of the power supply circuit based on the user's operation of the on / off key of the power supply, so that the backup power supply can operate even when the power supply is off. It is in a state. On the other hand, other microcomputers such as a mechanical controller are completely cut off in power and turned off when the power is turned off to reduce power consumption when not in use.

[0004]

Therefore, conventionally, when the power is turned off, the R of the microcomputer other than the mode controller is read.
AM data is lost completely. Therefore, when the power is turned on again, it is necessary to perform the initialization process.

If the data in the RAM of the microcomputer remains when the power is turned on again, such an initialization process becomes unnecessary and the next control can be immediately started. For example, the mechanical controller obtains tape information such as where the end of the tape is, and controls the feeding of the tape. If this tape information remains when the power is turned on again, the tape feed control can be restarted using this tape information.
However, if this data is lost, it is necessary to perform an initialization process to obtain the tape information.

Therefore, an object of the present invention is to provide an electronic device which can save the data of the microcomputer in the electronic device which does not have a backup function and can eliminate the need for the initialization process when the power is turned on again. To do.

[0007]

In an electronic device provided with a plurality of microcomputers, the contents of the RAM of the microcomputer not having the backup function are transferred to the RAM of the microcomputer having the backup function when the power is turned off. Therefore, when the power is turned on again, the initialization process becomes unnecessary and the control can be started immediately.

[0008]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings. FIG. 1 shows an embodiment of the present invention. In FIG. 1, 1 is a mode computer and 2 is a mechanical computer. Modecon 1 is key input from the user 3
Is a one-chip microcomputer for accepting and processing according to this key input. Mechacon 2
Is a one-chip microcomputer for controlling the mechanical operation unit 4, such as a drum motor or a capstan motor.

Reference numeral 5 is a power supply circuit. The power supply circuit 5 forms power from the battery 6 for each part having a predetermined power supply voltage. Power from the power supply circuit 5 is supplied to the signal processing circuit 9, the mechanical control unit 4, the mechanical control 2, and the mode control 1. The power supply circuit 5 is ON / OFF controlled by the mode controller 1 according to the key input 2.

Further, the switch circuit 7 is switched in accordance with the ON / OFF control of the power source. That is, when the power is turned on, the switch circuit 7 is set to the terminal 7A side. At this time, the power from the power supply circuit 5 is supplied to the mode controller 1 via the switch circuit 7. When the power is turned off, the switch circuit 7 is switched to the terminal 7B side. Therefore, the backup power supply 8 is supplied to the mode controller 1 via the switch circuit 7.

FIG. 2 is a flowchart showing the processing when the power is off. When the power-off command is supplied by the key input 3, the data in the RAM 12 of the mechanical controller 2 is transferred to the mode controller 1 by the communication line 13 (step 21).

When the data in the RAM 12 of the mechanical controller 2 is transferred to the mode controller 1, this data is transferred to the R of the mode controller 1.
It is stored in the AM 11 (step 22).

When the data in the RAM 12 of the mechanical controller 2 is stored in the RAM 11 of the mode controller 1, the power OFF signal is output from the mode controller 1. With this power off signal,
The power supply circuit 5 is turned off and the switch circuit 7 is switched to the terminal 7B side (step 23).

Since the power is not supplied to the mechanical control 2 after the power is turned off, the data in the RAM 12 of the mechanical control 2 is lost. However, the data in the RAM 12 of the mechanical controller 2 immediately before the power is turned off is the R of the mode controller 1.
It has been transferred to AM11. Therefore, the data in the RAM 12 of the mechanical controller 2 immediately before the power is turned off is stored in the RAM 11 of the mode controller 1 even after the power is turned off.

FIG. 3 shows the processing when the power is turned on. When the power-on command is input by the key input 3, the power-on signal is output from the mode controller 1. This power-on signal turns on the power supply circuit 5 and
The switch circuit 7 is switched to the terminal 7A side (step 31).

When the power is turned on, the RA of Modecon 1
RAM of Mechacon 2 up to the last time saved in M11
The data of 12 is read from the RAM 11 of the mode controller 1 (step 32).

Then, the previous data of the RAM 12 of the mechanical controller 2 stored in the RAM 11 of the mode controller 1 is transferred to the mechanical controller 2 via the communication line 13 (step 33).

In this way, after the power-on processing is performed, the original control processing is started. In this way, the initialization process when the power is turned on is unnecessary, and the original control process can be immediately started.

[0019]

According to the present invention, in an electronic device in which a plurality of microcomputers are arranged, the contents of the RAM of the microcomputer which does not have the backup function when the power is off are stored in the microcomputer having the back function. It is transferred to RAM. Therefore, when the power is turned on again, the initialization process becomes unnecessary and the control can be started immediately.

[Brief description of drawings]

FIG. 1 is a block diagram of an embodiment of the present invention.

FIG. 2 is a flowchart used to describe an embodiment of the present invention.

FIG. 3 is a flowchart used to describe an embodiment of the present invention.

[Explanation of symbols]

 1 Mode controller 2 Mechanical controller 5 Power supply circuit 8 Backup power supply

Claims (1)

[Claims] 1. An electronic device comprising a plurality of microcomputers, the operation of which is controlled by the plurality of microcomputers, wherein at least one of the plurality of electronic devices has a backup function to which a backup power is supplied when the power is turned off. When the power is turned off, the data of the microcomputer having no backup function is transferred to the microcomputer having the backup function and stored in the memory of the microcomputer having the backup function. Electronic equipment.