JP2000276347A - Portable electronic apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To make it possible to write a program in a non-volatile memory built in a portable electronic apparatus without using a writing program. SOLUTION: When a program write mode selection signal 111 received from a terminal interface 16 is activated and a write/read switching signal 112 is set up to 'write', a bus control circuit 11 stops a CPU 12 and releases a data bus 102 and an address bus 103. Then the circuit 11 supplies writing power 109 to a non-volatile memory 13, and after executing erasing operation, writes a program inputted from serial input data 114 received through the interface 16 in a specified address of the memory 13 through the address bus 103 and the data bus 102.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a portable electronic device, and more particularly to a writing method for writing a program for controlling the operation of a device in a nonvolatile memory inside the portable electronic device.

[0002]

2. Description of the Related Art Conventionally, writing of a main program into a nonvolatile memory in a portable electronic device has been performed by a CPU by activating a writing program different from the main program.

FIG. 3 is a block diagram showing the prior art.
In FIG. 3, the terminal interface 16 comprises:
Connected to the CPU 12 in the portable electronic device body 1,
Upon detecting that the program write mode selection signal 111 has become active, the CPU 12 copies the contents of the write program previously written in the non-volatile memory 13 from the non-volatile memory 13 to the memory 14, and then executes the write program. Execute.

[0004] When the nonvolatile memory 13 is shifted to the write mode of the main program, the previously written write program cannot be read, so that it is copied to the memory 14 which is another memory.
The CPU 12 executes the writing program copied to the memory 14.

Next, the CPU 12 writes the power supply 10 for writing to the nonvolatile memory 13 to shift the mode to the write mode.
9 is supplied to the nonvolatile memory 13, and the respective operations of writing, erasing, and resetting are in the writing mode set via the data bus 102. First, the CPU 12 executes the data bus 102 to erase the contents of the nonvolatile memory 13.
, The data indicating the erase is output, and the selection signal 106 and the write signal 105 are activated. Next, the CPU 12
Outputs data indicating write to the data bus 102, and activates the selection signal 106 and the write signal 105.

Subsequently, the CPU 12 outputs the address to the address bus 103 and the data to the data bus 102 in order to write the program input from the serial input data 114 of the terminal interface 16 to the specified address. The selection signal 106 and the write signal 105 are activated. Then, in order to write the next data, the address is output to the address bus 103 and the data is output to the data bus 102 again, and the selection signal 106 and the write signal 105 are activated. Thereafter, this operation is repeated, and all the programs input from the serial input data 114 are written to the specified address of the nonvolatile memory 13.

FIG. 2A shows a format of data input from the serial input data 114 of the terminal interface 16. BOF201 to EOF20
6 have a fixed bit length such as 1 word, for example, and the BOF 201 and EOF 206 are determined bit strings.

[0008] The ADR 202 has a DT which is the head of the data.
1.203 indicates the address of the nonvolatile memory 13 to which the data is written, and DT2.204 of the following data is ADR
The value is written to an address obtained by adding +1 to the value indicated by 202, the address is sequentially incremented, and the n-th data D
Tn. 205 is written to an address obtained by adding + n-1 to the value represented by the ADR 202. If the addresses are discontinuous, the data format is temporarily closed by EOF 206 and
Open as a new data format from OF201.
When the transfer of the program is completed, as shown in FIG.
A data format including only the BOF 201 and the EOF 206 is transmitted.

Next, as described above, the CPU 12 that has written all the data and received the bit string composed of only the BOF 201 and the EOF 206 means resetting the data bus 102 to shift the nonvolatile memory 13 to the read mode. Data to be output, and the selection signal 106 and the write signal 105 are activated. Thereafter, the writing to the nonvolatile memory 13 ends, and the mode is changed to the reading mode.

[0010]

However, the above prior art has the following problems. The first problem is that the program has a two-part configuration including a main program and a writing program. The reason is that the writing of the main program is executed by executing the writing program.

A second problem is that it is necessary to write a writing program in a nonvolatile memory using a dedicated writer before assembling the portable electronic device.
The reason is that the CPU executes the write program when the main program is written in the nonvolatile memory.

A third problem is that a writing program cannot be rewritten. The reason is that when a dedicated writer is used to write the program in the nonvolatile memory in advance, the program is written in a non-erasable space such as a boot area of the nonvolatile memory. This space can be written and erased only by a dedicated writer. This is to prevent the writing program from being erased when writing the main program.

Accordingly, an object of the present invention is to make it possible to write a main program without using a writing program.

[0014]

According to the present invention, an electronic circuit for executing various functions of a portable electronic device, a CPU for controlling the electronic circuit, and various signals are input. In a portable electronic device provided with an input unit, a bus control circuit that controls a bus that connects an electronic circuit and a CPU while various signals are input through the input unit, and a storage unit that stores a program, The bus control circuit stops the CPU in response to a program write selection signal input through the input means, releases the bus, sets the storage means to the write mode, and writes the next input program to the storage means. Like that.

[0015] The input program may have a write address to the storage means. Further, the program has a parameter indicating a target device in the apparatus, and the bus control circuit controls the input means. The data may be written to a specified address of the target device according to a write signal input via the input device, and the written data may be read and output according to a read signal input via the input means.

The storage means may be a non-volatile memory. Further, the bus control circuit may supply power to the storage means in the write mode,
Further, the storage means may be erased before writing to the storage means. Further, the CPU may control the operation of the device based on a program stored in the storage unit.

[0017]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a block diagram showing a first embodiment of a portable electronic device according to the present invention. The embodiment of the present invention relates to a main program of a portable electronic device, which is input from the outside of the portable electronic device, to a non-volatile memory 13 which is built in the portable electronic device main body 1 and which can be electrically written or erased. Is written. According to the present embodiment, it is no longer necessary to write a program for writing into a boot area or the like in the nonvolatile memory, which has been performed before assembling the portable electronic device.

In FIG. 1, according to the present embodiment, a bus control circuit 11 which has received a write mode request from a program write mode selection signal 111
2, the bus control circuit 11 operates the select signal 106 and the write signal 105 to change the main program input via the serial input data 114 into a nonvolatile program. Memory 13
To write to.

Hereinafter, the configuration and operation will be described in detail. In FIG. 1, a portable electronic device body 1 includes a bus control circuit 11, a CPU 12, a non-volatile memory 13, a memory 14, a portable electronic device circuit 15, which are mutually connected via a data bus 102 and an address bus 103. It consists of.

When the bus control circuit 11 receives the program write mode selection signal 111 from the terminal interface 16, the bus control circuit 11 releases the bus to the CPU 12 to shift the portable electronic device body 1 from the normal operation mode to the program write mode. Request signal 10
1 is supplied, and the power supply 109 for writing is supplied to the nonvolatile memory 13.

Subsequently, the bus control circuit 11 sends the synchronous clock 11 from the terminal interface 16.
3 receives the serial input data 114 input in synchronization with the data bus 3 and converts the data from serial to parallel.
02 at the same time as calculating the write address from the contents of the serial input data 114,
3 to make the selection signal 106 and the write signal 105 active, thereby realizing the function of writing to the nonvolatile memory 13.

When the portable electronic device body 1 is in the normal operation mode, the bus control circuit 11
2 by analyzing the address information output to the address bus 103 and activating each of the selection signal 106, the selection signal 107, and the selection signal 108,
PU 12 is connected to nonvolatile memory 1 via data bus 102
3, a memory 14, and a function to support reading and writing of data with each device of the portable electronic device circuit 15.

When the portable electronic device body 1 shifts to the main program write mode and receives the bus release request signal 101 from the bus control circuit 11, the CPU 12 releases the data bus 102 and the address bus 103, The operation stops itself.

When the portable electronic device body 1 is in the normal operation mode, the CPU 12 reads and executes a program from the nonvolatile memory 13 and writes the execution result in the memory 14 or the portable electronic device circuit 15 or data necessary for execution. From the memory 14 or the portable electronic device circuit 15.

The nonvolatile memory 13 is capable of electrically erasing and writing the written content, and retains the written content even when the power of the portable electronic device body 1 is off. When the portable electronic device body 1 shifts to the program writing mode, the nonvolatile memory 13 is supplied with the writing power supply 109 from the bus control circuit 11 and shifts to the writing mode in which writing or erasing is possible. In the write mode, when the select signal 106 and the write signal 105 become active, the data bus 1
02 is written to the address output on the address bus 103.

In the write mode, write, erase, and reset operations are set at the beginning of each operation. This outputs data indicating each operation of write, erase, and reset to the data bus 102,
It can be set by activating the selection signal 106 and the write signal 105.

When the portable electronic device body 1 is in the normal operation mode, it operates as a read-only memory,
When the selection signal 106 and the read signal 104 become active, the data written to the address output from the U12 to the address bus 103 is
Output to 2.

The memory 14 can be read and written when the power of the portable electronic device body 1 is ON, and the written contents are lost when the power of the portable electronic device body 1 is OFF. It is used as a work memory by the CPU 12 and is used to temporarily hold data generated during the execution of an instruction. The portable electronic device circuit 15 is an electronic circuit for realizing various functions of the portable electronic device body 1. For example, it is composed of various circuits, a display unit, a keyboard, a speaker, and the like.

The terminal interface 16 is an interface for connecting the terminal such as a computer, which outputs the above-mentioned program, to the portable electronic device main body 1, and selects the program writing mode for shifting the portable electronic device main body 1 to the program writing mode. A signal 111, a write / read switching signal 112 for setting whether to write a program or to read data, a synchronous clock 113 for sending / receiving timing of serial input data 114, and serial input data for inputting a program to be written and settings of the portable electronic device body 1 114, five signal lines of serial output data 115 for outputting data of the portable electronic device body 1.

FIGS. 2A and 2B show a format of data input from the serial input data 114 of the terminal interface 16 as described in the prior art.

Next, the operation of the above configuration will be described. In order to set the portable electronic device body 1 to the program write mode, the program write mode selection signal 111 is activated from the terminal interface 16 and the write / read switching signal 112 is set to write. Program write mode selection signal 1
Bus control circuit 1 that has detected 11 active
1 indicates that the operation of the CPU 12 is stopped and the data bus 1
02 and the request to release the address bus 103,
The bus release request signal 101 is activated.

The CPU 12 which has detected the activation of the bus release request signal 101 stops its operation, and
And release of the address bus 103. Subsequently, the bus control circuit 11 sends the write power 109 to shift the nonvolatile memory 13 to the write mode.
Supply. The nonvolatile memory 13 to which the writing power supply 109 is supplied shifts to the writing mode, and enters a state of waiting for each operation of writing, erasing, and resetting to be set via the data bus 102.

First, the bus control circuit 11 executes the data bus 1 to erase the contents of the nonvolatile memory 13.
02, data indicating erasure is output, and the selection signal 106
And the write signal 105 is activated. Next, in order to shift the nonvolatile memory 13 to the write mode, the bus control circuit 11 outputs data indicating write to the data bus 102, and activates the selection signal 106 and the write signal 105.

Subsequently, the bus control circuit 11 writes the address to the address bus 103 and writes the data to the data bus 102 in order to write the program input from the serial input data 114 of the terminal interface 16 to the specified address. Output and select signal 106
And the write signal 105 is activated. Then, in order to write the next data, the address and the data are output again to the address bus 103 and the data bus 102, and the selection signal 106 and the write signal 105 are activated. Thereafter, this operation is repeated, and all the programs input from the serial input data are stored in the nonvolatile memory 1.
3. Write to the specified address.

All data is written, and B in FIG.
The bus control circuit 11 that has received the bit string composed of only the OF 201 and the EOF 206 outputs data indicating a reset to the data bus 102 to shift the nonvolatile memory 13 to the read mode, and outputs the selection signal 106 and the write signal. Activate 105. Or later,
The writing to the nonvolatile memory 13 is completed, and the nonvolatile memory 13 enters the read mode.

Next, a second embodiment of the present invention will be described. This embodiment is configured as follows as an extension of the first embodiment. That is, FIG.
The format of the serial input data 114 is changed as shown in FIG.
7 is added, and the write / read switching signal 112 is set to write. As a result, data can be written to the nonvolatile memory 13, the memory 14, and the address specified by the ADR 202 of the portable electronic device circuit 15.

The write / read switching signal 1
When “12” is set to “read”, data can be read from the nonvolatile memory 13 and the memory 14 and the address specified by the ADR 202 of the portable electronic device circuit 15 and output to the serial output data 115. By using this function, it is possible to operate only some functions of the portable electronic device,
Since the setting of the circuit can be read and changed, it is also effective for failure diagnosis and function inspection.

[0038]

As described above, the first embodiment according to the present invention is described.
The advantage of this is that software can be constituted only by a main program. The reason is that a writing program for implementing a series of operations for writing to the nonvolatile memory is not required.

A second effect is that a nonvolatile memory in which nothing is written can be mounted on a portable electronic device. The reason is that the software is composed of only the main program, and the main program can be written after assembling the portable electronic device.

A third effect is that a write program for realizing a series of operations for writing to the nonvolatile memory is not required. The reason is that when there is a write request, the CPU is stopped and the program is written to the nonvolatile memory.

[Brief description of the drawings]

FIG. 1 is a block diagram showing an embodiment of a portable electronic device according to the present invention.

FIG. 2 is a configuration diagram showing a format of input data and a data format according to a second embodiment of the present invention.

FIG. 3 is a block diagram showing a conventional portable electronic device.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Portable electronic device main body 11 Bus control circuit 12 CPU 13 Non-volatile memory 14 Memory 15 Portable electronic device circuit 16 Terminal interface 101 Bus release request signal 102 Data bus 103 Address bus 104 Read signal 105 Write signal 106, 107, 108 Select signal 109 Write power supply 111 Program write mode select signal 112 Write / read switch signal 114 Serial input data 115 Serial output data

Claims (7)

[Claims] 1. An electronic circuit that executes various functions of a portable electronic device, a CPU that controls the electronic circuit, an input unit to which various signals are input, and the various signals are input via the input unit. A portable electronic device provided with a bus control circuit for controlling a bus connecting the electronic circuit and a CPU; and a storage unit for storing a program, wherein the bus control circuit receives an input via the input unit. C in response to a program write request signal
A portable electronic device, comprising: stopping a PU to release the bus, setting the storage unit to a write mode, and then writing a program input via the input unit to the storage unit using the bus. machine. 2. The portable electronic device according to claim 1, wherein the input program has a write address to the storage unit. 3. The input program has a parameter indicating a target device in the device, and the bus control circuit specifies the target device in accordance with a write signal input via the input means. 3. The portable electronic device according to claim 2, wherein data is written to the address, and the written data is read and output in response to a read signal input via the input means. 4. The portable electronic device according to claim 1, wherein said storage means is constituted by a nonvolatile memory. 5. The portable electronic device according to claim 1, wherein said bus control circuit supplies power to said storage means in said write mode. 6. The portable electronic device according to claim 1, wherein said bus control circuit erases said storage means before writing to said storage means. 7. The portable electronic device according to claim 1, wherein the CPU controls an operation of the electronic circuit based on a program stored in the storage unit.