JP2000200213A - Microcomputer, data rewriting system and data rewriting method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To make easily rewritable data in an external flash memory by analyzing a device identification code and obtaining a write routine corresponding to the flash memory, and rewriting the data in the flash memory. SOLUTION: When a device identification code read-in circuit 7 reads in a device identification code, a CPU 6 analyzes the device identification code and obtains the write routine corresponding to the flash memory 2 from a ROM 4. Namely, the write routine is obtained by using as a key the device identification code read in by the device identification read-in circuit 7. Then, the CPU 6 once obtaining the write routine executes the write routine to rewrite the data in the flash memory 2. Namely, rewrite data are written in a rewrite address added to a rewrite command.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a microcomputer, a data rewriting system, and a data rewriting method for executing a data rewriting process on an externally connected flash memory.

[0002]

2. Description of the Related Art In a conventional microcomputer (hereinafter, referred to as a microcomputer), when a flash memory is connected to an external device, the flash memory is not mounted before mounting the flash memory on a mounting board (hereinafter, referred to as a board). The data rewriting process can be executed by the flash alone by using a dedicated rewriting writer or the like (data can be written directly to the flash memory without using a microcomputer).

However, after the flash memory is mounted on the board, the microcomputer and the flash memory are connected on the board, so that data cannot be written to the flash memory without going through the microcomputer. General.

Further, when designing a board, a board designer can freely select a maker and a capacity of the flash memory connected to the microcomputer. After checking the specifications of the flash memory to be used, it is necessary to externally provide a microcomputer with a write routine (write program) corresponding to the flash memory. Alternatively, if the microcomputer supports a write routine corresponding to a plurality of types of flash memories, the microcomputer is required to execute the write routine corresponding to the flash memory connected to the microcomputer. It is necessary to give a command etc.

Therefore, in a device that rewrites data in a flash memory on-board, when a plurality of types of flash memories are mounted, it is necessary to confirm the flash memory that executes the data rewriting process. Rewriting work became very complicated.

On the other hand, in a microcomputer having a built-in flash memory, the rewriting operation is very simple, and data in the flash memory can be rewritten only by executing a rewrite command. For this reason, users often demand that the flash memory be built into the microcomputer. However, the capacity of the flash memory that can be built into the microcomputer is limited. It is necessary to carry out the work to rewrite the data in the external flash memory.

[0007]

Since the conventional microcomputer is configured as described above, if a write routine corresponding to the flash memory is provided from the outside, it is possible to execute the data rewriting process for the flash memory. However, in order to provide a write routine corresponding to the flash memory, there has been a problem that the user has to perform a troublesome operation such as checking the specifications of the flash memory.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problems. A microcomputer, a data rewriting system, and a data rewriting system capable of easily rewriting data even when rewriting data in an external flash memory. The aim is to get the method.

[0009]

A microcomputer according to the present invention analyzes a device identification code of a flash memory and obtains a write routine corresponding to the flash memory, and executes the write routine. And a data rewriting means for executing a data rewriting process for the flash memory.

[0010] The microcomputer according to the present invention comprises:
The identification code reading means is constituted by software.

[0011] The microcomputer according to the present invention comprises:
A memory for storing a device identification code output from the flash memory is provided.

[0012] The microcomputer according to the present invention comprises:
A memory for storing information indicating whether the reading process of the device identification code output from the flash memory is correct or not is provided.

[0013] The microcomputer according to the present invention comprises:
An output unit for externally outputting the device identification code stored in the memory is provided.

The data rewriting system according to the present invention is provided with command issuing means for issuing a data rewriting command to the microcomputer.

According to the data rewriting method of the present invention, a device identification code of a flash memory is analyzed to obtain a write routine corresponding to the flash memory.
By executing the write routine, data is rewritten to the flash memory.

[0016]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the present invention will be described below. Embodiment 1 FIG. FIG. 1 is a block diagram showing a microcomputer according to a first embodiment of the present invention. In the figure, reference numeral 1 denotes a microcomputer (hereinafter referred to as a microcomputer), 2 denotes an external flash memory connected to the microcomputer 1, and 3 denotes a microcomputer. A UART 4 for receiving a rewrite command or the like from a personal computer, a rewrite writer, or the like, 4 is a ROM for storing a plurality of types of write routines, and 5 is a RAM.

When the UART 3 receives the data rewrite command, it outputs an enable signal to the device identification code reading circuit 7, and when the device identification code reading circuit 7 reads the device identification code, it analyzes the device identification code. A CPU (identification code reading means, routine acquisition means, data acquisition means) for executing a write routine corresponding to the flash memory 2 from the ROM 4 and executing the write routine to rewrite data to the flash memory 2. Upon receiving the enable signal from the CPU 6, the rewriting means 7 outputs a control signal requesting the output of the device identification code to the flash memory 2, and reads a device identification code from the flash memory 2. Reading means). FIG. 3 is a flowchart showing a data rewriting method according to the first embodiment of the present invention.

Next, the operation will be described. For example, in order for the personal computer to rewrite the data stored in the flash memory 2, as shown in FIG. 2, the rewriting address (for example, "30000H") and the rewriting data (for example, "55
H ”) (for example,“ 41 ”).
H ”), the UART 3 receives a rewrite command to which a rewrite address and rewrite data are added (step ST1).

When the UART 3 receives the command, the CPU 6 decodes whether or not the command is a rewrite command (step ST2). If the command is a rewrite command, the CPU 6 obtains a device identification code for identifying the flash memory 2. In order to perform this, an enable signal is output to the device identification code reading circuit 7.

The device identification code reading circuit 7
Receives the enable signal from the CPU 6, outputs a control signal requesting the output of the device identification code to the flash memory 2, and executes a process of reading the device identification code from the flash memory 2 (step ST4).

When the device identification code reading circuit 7 reads the device identification code, the CPU 6 analyzes the device identification code and acquires a writing routine corresponding to the flash memory 2 from the ROM 4 (steps ST5 to ST5).
ST9). That is, since the ROM 4 stores write routines corresponding to various device identification codes, the device identification code read by the device identification code reading circuit 7 is used as a key to write data corresponding to the flash memory 2. Get the routine.

Then, the CPU 6 controls the flash memory 2
When the write routine corresponding to is obtained, the write routine is executed, and the data rewriting process for the flash memory 2 is executed. That is, a process of writing rewrite data to the rewrite address added to the rewrite command is executed.

As is apparent from the above, the first embodiment
According to the method, the device identification code of the flash memory 2 is analyzed to obtain a write routine corresponding to the flash memory 2, and the write routine is executed to execute a data rewrite process on the flash memory 2. With this configuration, the data in the flash memory 2 can be rewritten only by issuing a rewrite command in the same manner as in the built-in flash memory. As a result, even when the data in the external flash memory 2 is rewritten, This has an effect that data can be easily rewritten.

Embodiment 2 FIG. In the first embodiment described above, the device identification code of the flash memory 2 is read by providing dedicated hardware, that is, the device identification code reading circuit 7 is provided. However, the reading process of the device identification code is realized by software. You may make it.

More specifically, as in the first embodiment,
When the CPU 6 receives the rewrite command, it acquires a device identification code reading routine from the ROM 4 and executes the reading routine. As a result, the CPU 6 outputs a control signal requesting the output of the device identification code to the flash memory 2 and executes a process of reading the device identification code from the flash memory 2.

According to the second embodiment, the reading process of the device identification code is realized by software. Therefore, even if the reading method of the device identification code is changed in the future, the software is not changed without changing the hardware. The effect that can be dealt with simply by changing the parameter is achieved. Also, as shown in FIG.
Is unnecessary, so that the microcomputer 1 can be downsized.

Embodiment 3 FIG. 5 is a configuration diagram showing a microcomputer according to Embodiment 3 of the present invention.
In the figure, the same reference numerals as those in FIG. Reference numeral 8 denotes a register (memory) for storing the device identification code output from the flash memory 2. FIG. 6 is a flowchart showing a data rewriting method according to the third embodiment of the present invention.

Next, the operation will be described. When the data rewriting process for the flash memory 2 is performed for the first time (step ST11), the data rewriting process is executed in the same manner as in the first embodiment. At this time, the device identification code output from the flash memory 2 is replaced with the device identification code. Store in register 8.

In the second and subsequent data rewriting processes, the process of reading the device identification code from the flash memory 2 is not performed, and the data writing process is executed with reference to the device identification code stored in the register 8. To do it. As a result, in the data rewriting process for the second and subsequent times, it is not necessary to perform the process of reading the device identification code, so that the data rewriting speed is increased.

Embodiment 4 FIG. 7 is a configuration diagram showing a microcomputer according to Embodiment 4 of the present invention.
In the figure, the same reference numerals as those in FIG. Reference numeral 9 denotes a reading result flag (memory) for storing information indicating whether the reading process of the device identification code output from the flash memory 2 is correct or not, and reference numeral 10 denotes a PORT for externally outputting the contents stored in the reading result flag 9.
FIG. 8 is a flowchart showing a data rewriting method according to the fourth embodiment of the present invention.

Next, the operation will be described. In the third embodiment, the case where the device identification code output from the flash memory 2 is stored in the register 8 has been described. However, the result of reading the device identification code output from the flash memory 2, that is, the device identification code is normal. May be stored in the interpretation result flag 9 (step ST12).

Thus, if the contents stored in the interpretation result flag 9 are output to the outside through the PORT 10, even if a problem or the like occurs in the data rewriting process, the analyzing ability at that time is improved. To play.

Embodiment 5 FIG. FIG. 9 is a configuration diagram showing a microcomputer according to Embodiment 5 of the present invention.
In the figure, the same reference numerals as those in FIG. Reference numeral 11 denotes a PORT (output means) for externally outputting the device identification code stored in the register 8.

Next, the operation will be described. In the third embodiment, the case where the device identification code output from the flash memory 2 is stored in the register 8 has been described. For example, in response to a request from an external personal computer, the PO
The RT 11 may output the device identification code stored in the register 8 to the outside.

Thus, when a problem or the like occurs in the data rewriting process, the device identification code of the flash memory 2 can be confirmed, so that the analysis performance for the problem in the rewriting process is greatly improved.

Embodiment 6 FIG. FIG. 10 is a configuration diagram showing a data rewriting system according to Embodiment 6 of the present invention.
In the figure, the same reference numerals as those in FIG. Reference numeral 12 denotes a board on which the microcomputer 1 and the flash memory 2 are mounted, and reference numeral 13 denotes a personal computer (command issuing means) connected to the microcomputer 1 for issuing a rewrite command of data to which a rewrite address or rewrite data is added.
It is.

Next, the operation will be described. Although the point that the microcomputer 1 and the flash memory 2 are mounted on the same board 12 is different from that of the first embodiment, the operation itself of the microcomputer 1 is the same as that of the first embodiment. Therefore, the personal computer 13 is compatible with the first embodiment.
Similarly to the above, the data stored in the flash memory 2 can be rewritten only by issuing a rewrite command.

Thus, even when a plurality of types of flash memories 2 are mounted on the board 12, the user can easily execute the data rewriting process on the flash memory 2 without checking the specifications of the flash memory 2. It has the effect of being able to. In the sixth embodiment, the connection between the microcomputer 1 and the personal computer 13 is described. However, the present invention is not limited to this, and it goes without saying that a rewrite writer or the like may be connected.

[0039]

As described above, according to the present invention, the routine acquiring means for analyzing the device identification code of the flash memory and acquiring the write routine corresponding to the flash memory, and executing the write routine. Thus, since the data rewriting means for executing the data rewriting process for the flash memory is provided, even when rewriting the data of the external flash memory, the data can be easily rewritten.

According to the present invention, since the identification code reading means is constituted by software, even if the reading method of the device identification code is changed in the future, the software is changed without changing the hardware. There is an effect that can be dealt with just by doing. Further, since the device identification code reading circuit is not required, there is an effect that the microcomputer can be miniaturized.

According to the present invention, since the memory for storing the device identification code output from the flash memory is provided, it is not necessary to execute the device identification code reading process in the second and subsequent data rewriting processes. Therefore, there is an effect that the data rewriting speed is increased.

According to the present invention, since the memory for storing information indicating whether the reading process of the device identification code output from the flash memory is correct or not is provided, even if a problem occurs in the data rewriting process or the like. This has the effect of improving the analyticity at that time.

According to the present invention, since the output means for outputting the device identification code stored in the memory to the outside is provided, there is an effect that the resolvability of the rewriting process is greatly improved.

According to the present invention, since the command issuing means for issuing the data rewriting command to the microcomputer is provided, the user can easily rewrite the data to the flash memory without checking the specifications of the flash memory. There is an effect that the processing can be executed.

According to the present invention, the device identification code of the flash memory is analyzed to obtain a write routine corresponding to the flash memory, and the write routine is executed to perform a data rewrite process on the flash memory. Since it is configured to execute, even when rewriting data in an external flash memory, there is an effect that data can be easily rewritten.

[Brief description of the drawings]

FIG. 1 is a configuration diagram showing a microcomputer according to a first embodiment of the present invention.

FIG. 2 is an explanatory diagram illustrating an example of a rewrite command.

FIG. 3 is a flowchart showing a data rewriting method according to the first embodiment of the present invention.

FIG. 4 is a configuration diagram showing a microcomputer according to a second embodiment of the present invention.

FIG. 5 is a configuration diagram showing a microcomputer according to a third embodiment of the present invention.

FIG. 6 is a flowchart showing a data rewriting method according to Embodiment 3 of the present invention.

FIG. 7 is a configuration diagram showing a microcomputer according to a fourth embodiment of the present invention.

FIG. 8 is a flowchart showing a data rewriting method according to a fourth embodiment of the present invention.

FIG. 9 is a configuration diagram showing a microcomputer according to a fifth embodiment of the present invention.

FIG. 10 is a configuration diagram showing a data rewriting system according to a sixth embodiment of the present invention.

[Explanation of symbols]

2 flash memory, 6 CPU (identification code reading means, routine acquisition means, data rewriting means), 7 device identification code reading circuit (identification code reading means), 8 register (memory), 9 reading result flag (memory), 1
1 PORT (output means), 13 PC (command issuing means).

Claims (7)

[Claims] An identification code reading means for outputting a device identification code output request to a flash memory upon receipt of a data rewrite command, and executing a device identification code reading process from the flash memory; When the means reads the device identification code from the flash memory, the device identification code is analyzed to obtain a writing routine corresponding to the flash memory, and a writing routine obtained by the routine obtaining means. And a data rewriting means for executing data rewriting processing for the flash memory. 2. The microcomputer according to claim 1, wherein the identification code reading means is constituted by software. 3. The microcomputer according to claim 1, further comprising a memory for storing a device identification code output from the flash memory. 4. The apparatus according to claim 1, further comprising a memory for storing information indicating whether the reading process of the device identification code output from the flash memory is correct or not. Microcomputer. 5. The microcomputer according to claim 3, further comprising output means for externally outputting the device identification code stored in the memory. 6. A command issuing means for issuing a data rewrite command, and upon receiving a data rewrite command from the command issuing means, outputs a device identification code output request to the flash memory, and outputs the device identification code from the flash memory. Identification code reading means for executing a code reading process, and when the identification code reading means reads a device identification code from the flash memory, the device identification code is analyzed to obtain a writing routine corresponding to the flash memory. A data rewriting system comprising: a routine obtaining unit; and a data rewriting unit that executes a writing routine obtained by the routine obtaining unit and executes a data rewriting process on the flash memory. 7. When a data rewrite command is received, a device identification code output request is output to the flash memory. When the flash memory outputs a device identification code, the device identification code is analyzed and the flash memory is output. A data rewriting method for acquiring a write routine corresponding to the flash memory, executing the write routine, and performing a data rewrite process on the flash memory.