JPH04181803A - Tuning information storage system for communication satellite tuner - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Detailed Description of the Invention] [Field of Industrial Application] The present invention relates to a CATV business communication satellite tuner used in CATV stations etc., which normally continuously tunes the same communication line, and in particular relates to a CATV business communication satellite tuner that is used in a CATV station etc. This invention relates to a tuning information storage system for a communications satellite tuner that retains setting tuning information even when the microcomputer being used goes out of control and enables automatic recovery after restart.

[Prior Art] In general, a CATV commercial communication satellite tuner receives programs supplied from a program provider using a satellite line such as a communication satellite, and transmits the programs to CATV facility subscribed users who have a contract to receive the same programs. It is used to supply C
Install the same number of tuners for the number of satellite lines received by ATV stations and supplying programs to CATV facility subscriber users;-
A tuner to which a receiving line is set is configured to continue receiving the set line at all times. Therefore, as a function required for CATV commercial communication satellite tuners, it is necessary to constantly maintain the tuning state of the receiving line, to prevent erroneous operations by users, to prevent malfunctions due to noise, etc., and to prevent malfunctions in the event of malfunctions. Prompt detection and recovery are important.

In addition, in recent years, CATV commercial communication satellite tuners have become more multifunctional due to the increase in satellite lines and the diversification of line services.
Microcomputers are increasingly being used in the control system of tuner devices.

Generally, microcomputers used in CATV commercial communication satellite tuners and the like use a rewritable storage device (RAM or EEFROM) as a means for holding information necessary for control such as setting tuning information. The process that monitors the input switch status of the microcomputer rewrites the setting tuning information in this storage device when a tuning change instruction is received, and similarly controls the tuning status within the microcomputer. However, by reading this changed setting tuning information, the device shifts to a newly set tuning state.

Therefore, CATV commercial tuners that use the above-mentioned microcomputers in their control systems generally have panel locks that stop the microcomputer from monitoring the status of the input switches, as a measure to prevent erroneous operations by the user. Changing the tuning state due to erroneous operation is prevented by providing a switch called a switch and by providing a switch protection panel and a mechanism that makes it impossible to change the input switch. However, since the contents of the storage device are rewritten independently by the microcomputer, if the microcomputer goes out of control due to noise etc., there is a possibility that the setting tuning information may be rewritten. When the watchdog timer function of the runaway detection method used in the microcomputer is used to detect runaway and restart the microcomputer, the tuning information in the storage device is also initialized and the settings There is a problem that it becomes impossible to recover to the tuned state.

[Problem to be solved by the invention] Since it is important for CATV commercial communication satellite tuners to constantly maintain the tuned state of the reception line, even if the microcomputer goes out of control, it can be quickly corrected. It is desirable to detect and restore the set tuning state; therefore, the present invention makes it possible to write tuning information stored in a storage device that can be independently rewritten by a microcomputer unless the tuner operator intends to do so. By adding a function that reduces the probability that tuning information will be destroyed, it is possible to restore the setting tuning state even when the microcomputer runs out of control or when restarting after detection of runaway, and the setting tuning information is retained. An object of the present invention is to provide a tuning information storage method for a communication satellite tuner that can improve performance.

[Means and effects for solving the problem] External storage devices such as RAMs usually have a write/read switching terminal, and this switching terminal must be changed to the write state during write processing. Therefore, in the present invention, a storage device that holds setting information such as tuning information is provided as an external storage device separately from other storage devices necessary for normal processing. The external storage device used to hold this configuration information has its write/read switching terminal fixed in the normal read state, and the write process of the external storage device that holds the configuration information is separated from the dependency of the microcomputer processing. A write permission switch is provided. When this write permission switch is in the write permission state, the information held in the external storage device can be freely rewritten and read by the microcomputer, and when the permission switch is in the write protection state, the information is set to the write protection state. , so that it can only be read.

Therefore, when the tuner operator changes the tuning state, by setting this write permission switch to the write permission state, the setting tuning state can be changed and the information held in the external storage device can be rewritten. During normal operation without changing the tuning state,
Even if the microcomputer goes out of control and tries to rewrite the setting tuning information in the external storage device, or even if the microcomputer tries to initialize the information held in the external storage device when restarting the microcomputer, it will not be rewritten. Setting tuning information is retained.

By providing the above mechanism in the tuner device, the setting tuning information in the external storage device is retained even when the microcomputer runs out of control and is restarted, and by reloading the setting tuning information, it returns to the set tuning state. It is possible to recover.

[Example code] An embodiment of the present invention will be described below with reference to the drawings.

FIG. 1 is a block diagram showing the configuration of a control section of a CATV commercial tuner. In the figure, numeral 1 is a microcomputer that is the main control device, and the figure shows a 1-chip microcomputer that incorporates microcomputer peripheral devices such as ROM, RAM, and Ilo, which are commonly used in tuners and the like. using a computer. The micro computer 1 is connected to an input switch 2 that changes channels, satellites, and other conditions of the tuner device. The microcomputer 1 determines a change in the state of the tuner, thereby changing the control of the main body of the tuner device.

In addition, this input switch 2 has a mechanism to stop the microcomputer 1 from monitoring the status of the input switch 2 when a panel toilet switch is installed, and a mechanism to stop the microcomputer 1 from monitoring the status of the input switch 2, and a switch protection panel is installed when the input switch 2 is not needed. By making changes impossible, it is designed to prevent erroneous operations.

The display device 3 is for displaying the status of the tuner device such as the receiving satellite and the receiving channel, and is composed of an LED, a fluorescent display module, a liquid crystal display module, etc.
The display is controlled by the computer 1. The controlled device 4 includes a high frequency IC that constitutes a tuning system,
This device is a device such as an audio control module, and is a device that performs tuning of reception frequency, switching of input signals, and switching of audio output under the control of the microcomputer 1.

The backup power source 5 is composed of a battery or a large-capacity capacitor, and is a power source that stably supplies power supply voltage within a certain period of time even in the event of a power outage. The external storage device 6 is an external storage device added to hold information for controlling the display device 3 and the controlled device 4, and serves to hold setting tuning information such as receiving satellites and receiving channels. It is a device. The microcomputer 1 and the external storage device 6 are connected to an address bus 7 for specifying a data holding position in the external storage device 6, and a data bus 8 used for transmitting and receiving data between the microcomputer 1 and the external storage device 6.
, and sets the C8 (chip select) signal line 9, which activates the data input/output terminal of the external storage device 6 and sets the external storage device 6 to an accessible state, and the data input/output terminal of the external storage device 6 to the write mode. It is connected by a WE' (write enable) signal line 13 for switching to read mode.

FIG. 2 shows the logic circuit 11 from the microcomputer 1.
The state of the WE signal line 10 and the write permission switch 12 to
W to finally connect to the external storage device 6 depending on the state of
The state of the E' signal line 13 is shown.

When the microcomputer 1 performs data write processing to the external storage device 6, the τI signal line 9 is activated, and the WE signal line 10 from the microcomputer 1 to the logic circuit 11 is placed in a write state. At this time, the logic circuit 11 changes the state of the write enable switch 12 and W1.
Since the state of the signal line 10 is logically processed, unless the write enable switch 12 is ON, the WE' signal line 13 that is ultimately connected to the external storage device 6 will not be in the write state but will be in the read state, and the write process will not be performed. I can't do it. However, regardless of whether the write permission switch 12 is ON or OFF, the external storage device 6 can be read and set to the 8 state.
It can be executed without being affected by

As described above, by prohibiting the tuning information from being rewritten unless the tuner operator intends to do so, it is possible to reduce the probability that the tuning information will be destroyed.
Furthermore, by interlocking the write permission switch 12 with a panel lock switch generally used to prevent erroneous operation of the input switch 2 or the opening/closing of a switch protection panel, the write permission switch 12 can be controlled by the tuner operator.
It is possible to realize the function of transitioning the external storage device 6 for holding tuning information to a write-enabled state or a write-inhibited state without being aware of this.

Note that the external storage device 6 shown in the above embodiment is not limited to a RAM mounted on a printed circuit board, but a card type RAM, a magnetic disk, a magnetic card, etc. can be used.

[Effects of the Invention] As described above, according to the present invention, by providing a storage device and a logic circuit that hold setting information such as tuning information, and a write permission switch for the setting information storage device, the probability of the tuning information being destroyed is reduced. The setting tuning information is retained even when the microcomputer goes out of control.
It is possible to provide a highly reliable tuning information storage method for a communications satellite tuner that enables recovery to the set tuning state even during microcomputer runaway detection and restart processing.

[Brief explanation of drawings]

FIG. 1 is a block diagram showing the configuration of an embodiment of the present invention, and FIG. 2 is a diagram showing the state of the WE' signal line 13 depending on the state of the WE signal line 10 and the state of the write permission switch 12 in the same embodiment. It is. DESCRIPTION OF SYMBOLS 1... Microcomputer, 2... Input switch, 3... Display device, 4... Controlled device, 5...
Backup power supply, 6...RAM, 7...address bus, 8...data bus, 9...CS signal line, 10...WE signal line, ]1...logic circuit , 12・
...Writing permission switch, 13...WE' signal line. Applicant's agent Patent attorney Takehiko Suzue

Claims (1)

[Claims] In a communication satellite tuner equipped with a microcomputer as a tuning control device, a write/read switching terminal is provided separately from a storage device necessary for normal processing and stores setting information such as tuning information under the control of the microcomputer. and a write enable switch that normally fixes a write/read switching terminal of the external storage device in a read state and separates only write processing of the external storage device from a dependent relationship with microcomputer processing. A tuning information storage method for a communications satellite tuner, characterized by comprising: