JPH10177517A - Electronic equipment - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an electronic equipment which can easily rewrite the contents of a nonvolatile memory. SOLUTION: A nonvolatile memory 2 is connected to a microcomputer 1 for control which controls the internal circuit of electronic equipment. The microcomputer 1 discriminates whether a command inputted from an external control terminal 4 is a first command for controlling the internal circuit or a second command for writing data in the memory through the microcomputer 1. When the command is discriminated as the second command, the data corresponding to a control signal inputted from the control terminal 4 are written in the memory 2 through the microcomputer 1.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electronic device having a control microcomputer and a nonvolatile memory.

[0002]

2. Description of the Related Art In recent electronic devices such as television receivers and audio equipment, as shown in FIG. 4, a control microcomputer (hereinafter abbreviated as "microcomputer") 1 for controlling internal circuits is provided. Have. A nonvolatile memory 2 is connected to the microcomputer 1 by, for example, a bus line. In the case of a television receiver, the nonvolatile memory 2 stores preset data of electronic equipment such as channel data and volume data, last data immediately before power-off, and various adjustment data.

Recently, a function called a ROM correction is provided as a measure to cope with a bug in a program of the microcomputer 1, and when the microcomputer 1 has a ROM correction function, the nonvolatile memory 2 has the above function. In addition to the various data, a part of the program may be written.

In a factory, various data (or programs) are written in the nonvolatile memory 2 of the electronic device having such a configuration as follows. Microcomputer 1
A memory control terminal 3 is provided on a bus line connecting the memory and the nonvolatile memory 2, and a jig (not shown) is connected to the memory control terminal 3 to write adjusted data. At this time, there is a method of contacting a pin of a jig with a circuit pattern corresponding to the memory control terminal 3 in FIG. 1, or a method of connecting the memory control terminal 3 to a connector of the jig and connecting to the connector of the jig. .

Since all of these operations are performed on a line in a factory, the memory control terminal 3 is exposed on the substrate, but after being assembled as a product, the memory control terminal 3 is not connected to the outside. It cannot be seen, and the jig cannot be connected unless the housing (for example, the back cover) is removed.

[0006]

Incidentally, there are cases where it is necessary to rewrite data and programs in the nonvolatile memory 2 after shipping the electronic equipment. In such a case, since the memory control terminal 3 is not exposed to the outside as described above, first, the casing must be removed and the nonvolatile memory 2 must be rewritten using a service jig. Alternatively, the non-volatile memory 2 must be replaced with another non-volatile memory in which data and programs are written in advance. Such an operation is extremely complicated.

As a means for rewriting data and programs in the nonvolatile memory 2, there is a means using a service program. That is, using a special remote control transmitter,
The electronic device is set to the service mode by a special operation using a normal remote controller in a special procedure not normally performed by the user, and the contents of the nonvolatile memory 2 are rewritten by the service menu in the service mode. According to this method, there is no need to remove the housing of the electronic device,
If the data in the nonvolatile memory 2 needs to be rewritten by several tens or hundreds of bytes, it is extremely complicated and requires a large amount of manual work. There is also.

The present invention has been made in view of such a problem, and has as its object to provide an electronic device capable of easily rewriting the contents of a nonvolatile memory.

[0009]

SUMMARY OF THE INVENTION In order to solve the above-mentioned problems of the prior art, the present invention provides a control microcomputer for controlling an internal circuit, and a nonvolatile memory connected to the control microcomputer. An electronic device comprising: an external control terminal connected to the control microcomputer; and a command input from the external control terminal being a first command for controlling the internal circuit, A second program for writing data to the nonvolatile memory via the control microcomputer;
Determining means for determining whether the received command is a second command, and when the determining means determines that the command input from the external control terminal is the second command, the nonvolatile memory is controlled via the control microcomputer. An electronic apparatus characterized by comprising a writing means for writing data corresponding to a control signal input from the external control terminal to a memory.

[0010]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An electronic device according to the present invention will be described below with reference to the accompanying drawings. FIG. 1 is a block diagram showing an embodiment of the electronic device of the present invention, FIG. 2 is a diagram showing an example of control signals used in the electronic device of the present invention, and FIG. 3 is a diagram for explaining the operation of the electronic device of the present invention. It is a flowchart. In FIG. 1, the same parts as those in FIG. 4 are denoted by the same reference numerals.

In FIG. 1, a non-volatile memory 2 is connected to a control microcomputer (hereinafter abbreviated as “microcomputer”) 1 for controlling internal circuits by, for example, a bus line. This nonvolatile memory 2 includes:
In the case of a television receiver, preset data of electronic devices such as channel data and volume data, last data immediately before power-off, and various adjustment data are stored.

In a factory, various data (or programs) are written in the nonvolatile memory 2 of the electronic device having such a configuration as follows. Microcomputer 1
A memory control terminal 3 is provided on a bus line connecting the memory and the nonvolatile memory 2, and a jig (not shown) is connected to the memory control terminal 3 to write adjusted data. At this time, there is a method of contacting a pin of a jig with a circuit pattern corresponding to the memory control terminal 3 in FIG. 1, or a method of connecting the memory control terminal 3 to a connector of the jig and connecting to the connector of the jig. .

In the present invention, after assembling the housing of the electronic device, the non-volatile memory 2 is assembled as follows.
Write or rewrite data (or program) to Note that a program is also included in the data, and the data referred to in this specification includes a program to be written in a ROM collection or the like in addition to preset data, various adjustment data, and the like. The electronic device of the present invention includes an external control terminal 4. The external control terminal 4 does not need to be newly provided for the present invention, and an existing one may be used. That is, many recent electronic devices are provided with an external control terminal for interlocking operation between a plurality of devices. This type of external control terminal may be the external control terminal 4.

The external control terminal 4 is directly connected to the microcomputer 1 by a bus line. Normally, control signals (commands) for turning on / off the power of the device, switching channels, switching inputs, and the like are input to the external control terminal 4 as, for example, 8-bit digital signals. Also, when writing data to the nonvolatile memory 2, the service jig is connected to the external control terminal 4 and the following control signal is input to the microcomputer 1.

Here, a control signal input to the external control terminal 4 will be described. When writing data to the nonvolatile memory 2 via the microcomputer 1, the control signal is configured as shown in FIG. The head position in this control signal is determined by whether the control signal input to the external control terminal 4 is a normal command for controlling the internal circuit by the microcomputer 1 or the data is transferred to the nonvolatile memory 2 via the microcomputer 1. It is a special command 11 for identifying whether it is for writing.

As the special command 11, an empty code which is not used for controlling the internal circuit by the microcomputer 1 may be used. The control signal input to the external control terminal 4 is defined as a command for controlling a normal internal circuit, such as "00H" for powering on the device, and "01H" for channel up. Here, as an example, an empty code "FFH
Is a special command 11. H means a hexadecimal number. Further, in the control signal, following the special command 11, an address 12 of the nonvolatile memory 2 to which data is to be written and data 13 to be written to the nonvolatile memory 2 are alternately arranged. This address 12 and data 1
3 is 8 bits as an example.

When the control signal shown in FIG. 2 is input to the microcomputer 1, it can be seen from the special command 11 at the head that this control signal is for writing data to the nonvolatile memory 2. Then, as shown in FIG.
The data of 34H is written to the address 20H of the nonvolatile memory 2, and the data of 9AH is written to the address 21H.

Here, the operation of the microcomputer 1 in the electronic apparatus of the present invention will be further described with reference to FIG. FIG.
In step S1, data is fetched. The data fetched in step S1 is the data at the head position of the control signal input to the external control terminal 4. Step S
In 2, it is determined whether or not the fetched data is FFH representing the special command 11. That is, the microcomputer 1
Is a command for controlling an internal circuit in the control signal input from the external control terminal 4 or a command for writing data to the nonvolatile memory 2 via the microcomputer 1. There is provided a determining means for determining whether

If the fetched data is FFH, the control signal input from the external control terminal 4 is a command for writing data to the nonvolatile memory 2 via the microcomputer 1, so that the processing is executed at step S3. Move to
On the other hand, if the captured data is not FFH, the control signal input from the external control terminal 4 is a normal command for controlling each part of the circuit via the microcomputer 1, so that
In this case, the processing shifts to the normal processing.

Then, in step 3, further data is fetched, and the fetched data is defined as x.
To set the memory write address to address x. Further, in step 5, data is fetched, and the fetched data is defined as y. In step 6, data y is stored in the nonvolatile memory 2.
Write. In step 7, it is determined whether or not the data has been completed. If the data has not been completed, the process returns to step S3, and if completed, the process proceeds to the next process. That is, when it is determined that the command input from the external control terminal 4 is a command for writing data to the nonvolatile memory 2, the microcomputer 1 sends the command from the external control terminal 4 to the nonvolatile memory 2 via the microcomputer 1. There is provided writing means for writing data corresponding to the input control signal.

By the above series of processing, the external control terminal 4
It is determined whether the control signal input to is a normal command for controlling the internal circuit by the microcomputer 1 or a command for writing data to the nonvolatile memory 2 via the microcomputer 1. And the non-volatile memory 2
In the case of writing data to the
Data is written to the nonvolatile memory 2 according to the correspondence between the memory write address and the data to be written as shown in FIG.

As can be seen from the above description, according to the present invention, since the operation of writing data to the nonvolatile memory 2 is performed by the microcomputer 1, it can be executed at high speed and continuously, and has a large capacity for writing a program. Even when data is written to the non-volatile memory 2, the data is not manually written by using a service program as in the related art, but is performed by a service jig. Therefore, there is no danger of writing erroneous data. Further, since the processing of the microcomputer 1 for this is all processing of software, it can be realized very easily. In addition, as described above, the special command 11, address 12, data 1
If 3 is the same 8-bit data as a normal command, the processing load of the new software is small.

In the above description, the method of writing data to the non-volatile memory 2 in the factory has been described by using the memory control terminal 3 as in the prior art. It goes without saying that the method according to the present invention using the external control terminal 4 may be used for writing.

[0024]

As described in detail above, in the electronic apparatus of the present invention, the external control terminal connected to the control microcomputer and the command input from the external control terminal control the internal circuit. And a second command for writing data to the nonvolatile memory via the control microcomputer, and a command inputted from an external control terminal by the discriminating means. When it is determined that the received command is the second command, a writing means for writing data according to a control signal input from an external control terminal to the nonvolatile memory via the control microcomputer is provided. The contents of the nonvolatile memory can be easily rewritten without removing the housing of the electronic device.

[Brief description of the drawings]

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

FIG. 2 is a diagram illustrating an example of a control signal used in the present invention.

FIG. 3 is a flowchart for explaining the operation of the present invention.

FIG. 4 is a block diagram showing a conventional example.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Control microcomputer 2 Non-volatile memory 2 3 Memory control terminal 4 External control terminal

Claims (2)

[Claims] An electronic device comprising: a control microcomputer for controlling an internal circuit; and a non-volatile memory connected to the control microcomputer, comprising: an external control terminal connected to the control microcomputer; A command input from the external control terminal is a first command for controlling the internal circuit, or a second command for writing data to the nonvolatile memory via the control microcomputer. Discriminating means for discriminating whether the command is a command, and when the discriminating means discriminates that the command input from the external control terminal is the second command, the nonvolatile memory via the control microcomputer Writing means for writing data according to a control signal input from the external control terminal to An electronic device characterized by being configured with. 2. The control signal according to claim 1, wherein a start position of the control signal is the command, and following the command, an address of the nonvolatile memory and data to be written to the nonvolatile memory are alternately arranged. The electronic device according to claim 1.