JP3050742U - Bus communication device and VCR - Google Patents

Abstract

(57) [Problem] To provide communication control by preparing two types of bus lines for a constant power supply device and a main power supply device, and the configuration may be complicated. SOLUTION: In a video deck equipped with various devices connected to one bus line 80 and capable of communicating with each other, when a main power switch 90 is turned off, channel data stored in a memory IC 70 by a microcomputer 60 when the main power switch 90 is off. When reading the video I, the microcomputer 60 sends a control signal to turn on the main power switch 90 and
The power supply to the C20 and the HiFi IC 30 is also started, and after the reading of the same channel data is completed, the main power switch 90 is turned off to stop the power supply.

Description

[Detailed description of the invention]

[0001]

[Technical field to which the invention belongs]

 The present invention relates to a bus communication device having a plurality of devices capable of communicating via a bus line and a VCR equipped with the bus communication device, and in particular, power is not supplied when performing communication between predetermined devices. It relates to a bus communication device and a VCR in which devices are mixed.

[0002]

[Prior art]

 Conventionally, the following video deck has been known as an application example of this type of bus communication device. In many video decks, channel preset data is stored in a memory IC such as an EEPROM, and the channel preset data is read by a microcomputer when an AC code is connected, and channel control is performed by the microcomputer. The microcomputer and the memory IC are connected by a predetermined bus line, and data is read through the bus line.

[0005] Also, the processing related to the actual television signal is performed by an IC device such as a video IC or a HiFiIC. Communication between the IC device and the microcomputer is similarly performed via a bus line. Therefore, if all the IC devices such as the memory IC, the video IC, and the HiFiIC are connected to one bus line, it goes without saying that the configuration becomes easy. However, as described above, since communication is performed between the microcomputer and the memory IC when the AC cord is connected, that is, while the main power is off, both are always supplied with power, while the video IC and the memory IC are connected. In the case of HiFiIC or the like, power supply is normally started in synchronization with turning on the main power supply. Then, a video IC, a HiFiIC, or the like to which power is not supplied is applied with a voltage higher than the standard through the bus line, and may be destroyed. The voltage of the entire bus line is reduced by the IC device. In some cases, communication became impossible due to a decrease.

In order to avoid such adverse effects, it is sufficient to always supply the internal power to all the IC devices internally, but this is not advisable due to the problem of power consumption. Therefore, in many cases, the bus lines used for the microcomputer and the memory IC, which are always supplied with power, and the video IC and the HiFi IC, which are supplied with power synchronously with the main power supply, are separated from each other. Such an adverse effect was avoided.

On the other hand, Japanese Patent Application Laid-Open No. Sho 61-123913 discloses a personal computer system including devices such as a CPU, a ROM and a RAM that can communicate with each other via a bus line. In this personal computer system, the power is automatically turned on when an external signal is supplied, and after a series of processing is completed, the signal supply status is determined and the power is automatically turned off. In addition to preventing power consumption, it does not turn off the power while accessing the device, preventing data loss.

[0006]

[Problems to be solved by the invention]

 The conventional technique described above has the following problems. In the former, two types of bus lines must be prepared and communication control of each bus line must be performed, and the configuration becomes complicated. In the latter case as well, devices that always supply power and devices that start supplying power when the main power is turned on coexist, and may communicate between devices while the main power is off. In such a case, a similar problem may occur.

The present invention has been made in view of the above problems, and has as its object to provide a bus communication device and a video deck capable of preventing unnecessary power consumption and facilitating communication control of a bus line. I do.

[0008]

[Means for Solving the Problems]

 In order to achieve the above object, the invention according to claim 1 provides a power supply line that constantly supplies power while being connected to a power supply, and a power supply that synchronizes with turning on and off a predetermined main power switch. A main power supply line for connecting the devices, a bus line for connecting the devices to enable mutual communication, and a plurality of continuous power supply devices connected to the bus line and receiving power supply from the continuous power supply line. The main power switch connected to the bus line and receiving power from the main power line and the main power switch for communication between the constant power device when the main power switch is off are connected to the main power switch. Main power switch control means for turning on and turning off the main power switch after communication is completed is provided.

In the invention according to claim 1 configured as described above, a continuous power line that constantly supplies power while connected to a power supply, and a power supply that synchronizes with the on / off of a main power switch. And a main power supply line for supplying power to the main power supply device, and the main power supply device receives power supply from the former at all times. These devices are connected to one bus line and can communicate with each other.However, even while the main power is off, power is always supplied to the power supply devices. It is also possible that communication is performed by using. At this time, the main power switch control means turns on the main power switch when performing communication between the power devices at all times. Then, communication is always performed between the power supply devices while the power is also supplied to the main power supply device. Then, the main power switch control means turns off the main power switch after the communication is completed to stop the power supply to the main power device.

Here, the constant power supply line is a power supply line that always supplies power while the power supply is connected. For example, an electronic device that always needs power supply such as a clock circuit having a clock function. It supplies power to parts. Further, when there are a plurality of such electronic components, the electronic components are not necessarily limited to a single power supply line. That is, when there are a plurality of electronic components that always require power supply, the case where each of the electronic components is configured by a separate power supply line is naturally included. On the other hand, the main power supply line is a power supply line that supplies power while the main power supply switch is on, and in many cases, power is supplied to electronic components that need to be supplied only during actual use. Is used to supply The specific on / off of the main power switch may be switched by operating a predetermined “POWER button”, or may be internally switched by a so-called timer function. . Of course, such a main power supply line is also the same as the above-mentioned constant power supply line, and need not be constituted by one power supply line, but may be constituted by a plurality of power supply lines.

A bus line is a transmission path for transmitting data and is shared by a plurality of electronic components, and its use and the type of actual transmission data are not particularly limited. Widely applicable without. The term “electronic component” as used herein means a device that transmits and receives data widely, and may be a single unit such as a memory, or may be a plurality of electronic members assembled and communicated as a single unit. May be performed, and these are collectively called devices. Therefore, the always-on power supply device is any electronic component that communicates via the bus line while receiving power supply from the above-mentioned always-on power supply line, and the main power supply device is similarly supplied with power from the main power supply line. Any electronic components that receive and communicate via the bus line, and the quantity of each is completely arbitrary.

The application target of such a bus communication device is not particularly limited, but a video deck is considered as a preferable example. In view of the above, the invention according to claim 2 comprises a continuous power supply line that constantly supplies power while being connected to a power supply, and a main power supply that supplies power so as to be synchronized with turning on / off a predetermined main power switch. One bus line that connects the line and various devices so that they can communicate with each other, a tuner that selects a channel based on predetermined channel data, and a tuner that is connected to the bus line and always A nonvolatile memory IC that stores the channel data while receiving power from a power supply line, and performs predetermined television signal processing while being connected to the bus line and receiving power from the main power supply line A signal processing IC for outputting a signal via the bus line when the main power switch is turned off while receiving power from the constant power line. When reading the channel data from the bus, turn on the main power switch and turn off the main power switch after the reading is completed, and perform channel selection control on the tuner based on the read channel data while passing through the bus line. And a microcomputer for controlling the operation of the signal processing IC.

[0013] In the invention according to claim 2 configured as described above, a continuous power line that constantly supplies power while being connected to a power supply, and a power supply that synchronizes on / off of a main power switch. And a main power supply line for supplying power to the memory IC and the microcomputer from the former, and power to the signal processing IC from the latter. These devices are connected to one bus line so that they can communicate with each other. When the main power switch is off, the microcomputer reads the channel data stored in the memory IC and reads the main power. The actual reading is performed after the switch is turned on and power is also supplied to the signal processing IC. Then, after the reading is completed, the main power switch is turned off to stop the power supply to the signal processing IC. The microcomputer controls the tuning of the tuner based on the channel data thus read, and controls the operation of the signal processing IC to perform the television signal processing.

Here, the signal processing IC is an IC device whose power supply is started when the main power switch is turned on, and may be any device that performs television signal processing. It may be composed of devices, or may be composed of a plurality of IC devices. For example, the latter includes a video IC that performs video signal processing and an audio IC that performs audio signal processing.

By the way, if power is supplied to the signal processing IC to make it operable, noise may be output although there is no original signal input. Therefore, a device according to claim 3 is the video deck according to claim 2, wherein the microcomputer does not output a signal to the signal processing IC when the channel data is read.

In the device according to claim 3 configured as described above, when the microcomputer reads the channel data from the memory IC, the signal processing IC is supplied with power as described above to be in an operable state. However, the microcomputer does not allow the signal processing IC to output a signal. In order not to output a signal, it is sufficient that at least the above-mentioned noise is not output, and a specific configuration is not limited and various types of configurations can be applied. . For example, the signal processing IC may be muted, or a signal output path may be controlled through a relay switch or the like so as not to be output to the outside.

[0017]

[Effect of the invention]

 As described above, in the present invention, when communication is performed via the bus line while the main power switch is off, power is also supplied to the main power device. It is possible to provide a bus communication device that can connect devices and that can easily control communication on a bus line while preventing unnecessary power consumption.

According to the invention of claim 2, all devices can be connected to one bus line in the same manner, and communication control of the bus line can be easily performed while preventing wasteful power consumption. A video deck that can be used as a video deck can be provided.

Further, according to the invention of claim 3, when the microcomputer reads the channel data from the memory IC, the signal processing IC is also supplied with power and becomes operable, but no signal is output to the outside. As a result, no noise is generated.

[0020]

[Embodiment of the invention]

 Hereinafter, embodiments of the present invention will be described with reference to the drawings. FIG. 1 is a schematic block diagram showing the flow of signal processing in a video deck to which a bus communication device according to an embodiment of the present invention is applied. FIG. 2 is a diagram showing the power supply system of various devices in the video deck. The connection is shown by a schematic block diagram. In the figure, the video deck is provided with a tuner 10 for selecting and receiving a television broadcast, and a signal received by the tuner 10 is separated into a video signal and an audio signal by a detection circuit (not shown). Output to IC20 and HiFiIC30.

The video IC 20 and the HiFi IC 30 perform various processes on the separated video signal and audio signal, and record the processed signals on a predetermined track of a video tape via the drum head 40. Also, at the time of reproduction, the signal read out via the drum head 40 is appropriately amplified by the video IC 20 and the HiFi IC 30 and output, and output as a VHF “1ch” or “2ch” television signal via the RF converter 50. Is done. Of course, in the present embodiment, the video IC 20 and the HiFi IC 30 constitute a signal processing IC. Although not shown, it goes without saying that various motors such as a reel motor and a capstan motor, as well as a servo circuit for the drum and the capstan are naturally provided.

The operations of the tuner 10, the video IC 20, the HiFi IC 30, and the various motor systems are appropriately controlled by the microcomputer 60 to perform actual recording / playback processing. Next, the tuner 10 employed in this embodiment is used. The channel selection control will be described. The tuner 10 employs a PLL method, and changes a reception frequency based on predetermined channel data input from the microcomputer 60. The channel data transmitted from the microcomputer 60 is set by the channel preset function.

The channel preset function automatically searches for a broadcast channel and stores an actual broadcast channel, and is generally performed when a video deck is newly installed. Specifically, when a predetermined operation is performed from a remote controller (not shown) or the like, the microcomputer 60 detects and gives channel data to the tuner 10 in order from the lowest channel. It is determined whether or not the broadcast channel is an actual broadcast channel. When the broadcast channel is determined to be an actual broadcast channel, the broadcast channel is stored in a nonvolatile memory IC 70 such as an EEPROM, and also stored in a storage area inside the microcomputer 60. Then, the contents stored in the memory IC 70 are, for example, as shown in FIG.

As described above, while the channel data is stored in the nonvolatile memory IC 70 and the same channel data is stored internally in the microcomputer 60, it is better to store the channel data inside the microcomputer 60. On the other hand, if the channel data is stored only inside the microcomputer 60, the stored channel data may be lost. For example, in the case of a short-term power failure such as an instantaneous interruption, the channel data in the microcomputer 60 is retained due to the internal capacitance and the like. Because it will not be. Therefore, in the present embodiment, when the power supply to the microcomputer 60 is stopped for a long time and internal information is lost, the microcomputer 60 reads the channel data stored in the memory IC 70 when the power supply is resumed. It is designed to read.

In FIG. 2, various devices such as the tuner 10, the video IC 20 and the HiFi IC 30, the microcomputer 60, and the memory IC 70 are connected via the bus line 80 and can communicate with each other. However, communication is performed between the microcomputer 60 and the tuner 10 or between the microcomputer 60 and the video IC 20 and the HiFi IC 30 via the bus line 80.

Among the various devices, the microcomputer 60 and the memory IC 70 are always connected to a power supply line, and are always supplied with power when supplied from an AC power supply. On the other hand, the video IC 20 and the HiFi IC 30 are to operate only while the main power is on, and are connected to the main power line. The main power can be turned on / off by operating a “POWER button” of a remote control (not shown), and the microcomputer 60 detects this operation and turns on the main power switch 90 interposed in the main power line. Turn on / off. Therefore, power is supplied to the video IC 20 and the HiFi IC 30 only while the main power switch 90 is on.

Here, a case is considered in which after the channel preset is completed, the power supply is stopped for a long time due to, for example, a power outage, and the power is restored after that. Then, since the channel data stored inside the microcomputer 60 is lost, the microcomputer 60 reads the contents stored in the memory IC 70 via the bus line 80 after the power failure is restored. However, at this time, the main power switch 90 is not turned on, and power is not supplied to the video IC 20 and the HiFi IC 30, so that a voltage higher than the standard is applied to these devices via the bus line 80 and the devices are destroyed. It can be assumed that the communication between the microcomputer 60 and the memory IC 70 becomes impossible due to a decrease in the voltage of the bus line 80.

Therefore, when performing the actual reading, the microcomputer 60 turns on the main power switch 90 to start the power supply to the video IC 20 and the HiFi IC 30, and after reading the contents stored in the memory IC 70, turns on the main power switch 90. Turn off and stop power supply. Although not described above, in the present embodiment, as a specific configuration of the main power switch 90, the main power switch 90 is configured by a switching element such as a switching transistor, and responds to a control signal from the microcomputer 60. On / off control.

Originally, the power supply to the video IC 20 and the HiFi IC 30 is useless at the time of reading the storage contents of the memory IC 70, but the reading is completed in a short time. Can be said to be extremely insignificant, and instead, it is preferable that the destruction of the video IC 20 and the HiFiIC 30 and the loss of communication on the bus line 80 can be avoided.

Incidentally, the fact that power is supplied to the video IC 20 and the HiFi IC 30 is nothing but a state in which the IC can be operated. Of course, even if there is no signal input to such an IC device, it is possible that some noise is picked up and an output is obtained. Therefore, when reading the contents stored in the memory IC 70, the microcomputer 60 performs muting so that no signal is output from the video IC 20 and the HiFi IC 30. Note that a specific configuration related to the muting is within the category of the related art, and thus will not be described in detail here.

Next, the operation of the present embodiment configured as described above will be described with reference to the timing chart of FIG. First, when a channel preset is completed according to a predetermined procedure when a video deck is newly installed, channel data relating to an actual broadcast channel is stored in the memory IC 70, and the microcomputer 60 stores the channel data in an internal storage area. The tuner 10 controls the tuner 10 based on the channel data. Further, the normal recording and reproduction are also performed by the microcomputer 60 by appropriately controlling the operations of the video IC 20 and the HiFi IC 30.

After the channel preset is completed as described above, it is assumed that a long-term power failure occurs as shown in FIG. 4, and the power is restored after that. Then, the power supply to the microcomputer 60 is also stopped, and the channel data stored therein is lost. Therefore, when the power failure is restored, the microcomputer 60 reads the stored contents of the memory IC 70 in order to restore the internal channel data, but sends a control signal to start the main power switch 90 before starting the actual reading. To

Then, since power is supplied to the video IC 20 and the HiFi IC 30 connected to the main power supply line, the destruction of the IC device is prevented, and the voltage of the bus line 80 is also kept normal, so that the memory IC 70 The reading is also performed normally. When the reading from the memory IC 70 is completed, the microcomputer 60 turns off the main power switch 90 and stops the power supply to the video IC 20 and the HiFi IC 30. Note that the microcomputer 60 mutes the video IC 20 and the HiFi IC 30 during reading from the memory IC 70 so that noise is not output.

As described above, in the video deck provided with various devices connected to one bus line 80 and capable of communicating with each other, when the main power switch 90 is off, the microcomputer 60 stores the data in the memory IC 70. In reading the channel data, the microcomputer 60 sends a control signal from the microcomputer 60 to turn on the main power switch 90 to start supplying power to the video IC 20 and the HiFi IC 30 and to read the main power after the reading of the channel data. Since the power supply is stopped by turning off the switch 90, communication control of the bus line can be facilitated while preventing wasteful power consumption.

[Brief description of the drawings]

FIG. 1 is a schematic block diagram showing a flow of signal processing in a video deck to which a bus communication device according to an embodiment of the present invention is applied.

FIG. 2 is a schematic block diagram showing connections of power supply systems of various devices in the video deck.

FIG. 3 is a table schematically showing storage contents of a memory IC.

FIG. 4 is a timing chart showing voltage changes of a main power supply and an AC power supply when a power failure occurs.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 ... Tuner 20 ... Video IC 30 ... HiFiIC 40 ... Drum head 50 ... RF converter 60 ... Microcomputer 70 ... Memory IC 80 ... Bus line 90 ... Main power switch

Claims (3)

[Utility model registration claims] A connection is made between a constant power supply line that constantly supplies power while being connected to a power supply, a main power supply line that supplies power in synchronization with turning on / off a predetermined main power switch, and devices. A bus line connected to the bus line and receiving power from the constant power line; and a main power line connected to the bus line and connected to the bus line. When the main power switch is turned off and the main power switch is turned off, the main power switch is turned on and the main power switch is turned off after the communication is completed in performing communication between the constant power devices. A bus communication device comprising: a main power switch control unit. And a main power supply line for supplying power so as to be synchronized with turning on / off of a predetermined main power supply switch. A bus line for connecting and communicating with each other, a tuner for selecting a channel based on predetermined channel data, and a channel line connected to the bus line and receiving power from the constant power line. A signal processing IC connected to the bus line and performing predetermined television signal processing while receiving power supply from the main power supply line to output a signal; and When the main power switch is off while receiving power, channel data is transmitted from the memory IC via the bus line. Upon reading, the main power switch is turned on, and after the reading is finished, the main power switch is turned off. A video deck comprising a microcomputer for controlling operation 3. The video deck according to claim 2, wherein the microcomputer does not output a signal to the signal processing IC when reading the channel data.