JP4325786B2 - How to download the program - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a program download method , and more particularly to a program download method for updating a nonvolatile memory such as a flash memory by communicating with a PC (personal computer) or the like.
[0002]
[Prior art]
In the conventional program download method , as shown in FIG. 7, a PC having a file transfer function or a PC in which a program having a file transfer function is installed writes a program file such as an Intel hexa format stored in ASCII format. Data is read from the inserted media and transmitted.
[0003]
The download target device transfers the data received from the PC 10 by the serial controller 60 to the CPU 30, and the CPU 30 repeats the operation of storing the data transferred from the serial controller 60 in the RAM 50.
[0004]
When the CPU 30 receives all the data and receives an instruction to update the flash memory 40 from the PC 10, the CPU 30 writes the download file data received from the PC 10 and stored in the RAM 50 into the flash memory 40.
[0005]
According to this method, there is a possibility that the data of the download file stored on the RAM 50 that has not been determined whether or not an error has occurred at the time of reception is written to the flash memory 40 as it is, and the data reliability is low. There was a problem.
[0006]
Therefore, in order to improve the reliability of the data of the received download file, the program download method described in Patent Document 1 calculates the sum of the data of the download file by the sum calculation circuit 80 as shown in FIG. The data stored on the RAM 50 is compared with the sum added to the download file in advance, and the data of the downloaded file on the RAM 50 received and stored is evaluated before writing.
[0007]
[Patent Document 1]
Japanese Patent Laid-Open No. 2000-122848
[Problems to be solved by the invention]
However, in the above-described conventional program downloading method , only the check of the sum added for each line is performed. For example, in the case of an Intel hexa format file, the record mark (':') to the new line ('¥ n') When all the data of one line up to the code could not be received, the abnormality of the received data cannot be detected, and there was a problem in the reliability of the data of the received download file.
[0009]
In addition, when data that does not affect the sum added to the download file could not be received, for example, when the download file is in Intel hexa format, the following line: “1020304060000000000000000000000000000000”
In other words, if the data of the line where the sum of the new line ('\ n') code is 0x00 cannot be received from the record mark (':'), the sum of the downloaded files will match, so the received data Even if it is not possible to detect any abnormalities in the data, or even if it is not possible to receive a plurality of lines of data whose sum is 0x00, the totals of the downloaded files will match, so the abnormalities in the received data Even if it cannot be detected and a sum is added to the download file, there is a problem in the reliability of the received data.
[0010]
Therefore, the present invention has been made in view of the problems in the conventional program download method described above, and improves the reliability of received data, speeds up transmission / reception processing, and simplifies the apparatus configuration. An object of the present invention is to provide a program download method that can be used.
[0011]
[Means for Solving the Problems]
In order to achieve the above object, the present invention provides a program download method for transmitting an Intel hexa format or S format program file from one device and downloading the program file to the other device. , Adding information about the total number of lines of the program file, transmitting the file, and storing the received program file in the RAM in the other device, and performing a checksum for each line of the received program file And the number of lines of the received program file is counted and compared with the added total number of lines to indicate that the result of the sum check process has received correct data, and the number of counted lines when said number of appended total rows and matches, the received data and It is determined that there is no error, and writes the program file stored in the RAM in the nonvolatile memory.
[0012]
According to the present invention, by adding the number of lines of the entire file as data, it is possible to detect missing reception of data in file transfer and improve the reliability of received data.
[0013]
In addition, since the reliability of data is improved by adding the number of lines in the entire file as data, the amount of data transferred compared to the method of improving reliability by adding headers and packet numbers to the data in each line By reducing the number of times, the data transfer time can be increased. Further, compared to the method of adding the sum of the entire file to improve the reliability, it is possible to speed up the transmission / reception process by eliminating the calculation of the sum.
[0014]
Furthermore, since the reliability of the data is improved by adding the number of lines of the entire file as data, a method of improving the reliability by adding a header or packet number to the data of each line, Compared with a method of improving reliability by calculating and adding to data, the apparatus configuration can be simplified.
[0016]
DETAILED DESCRIPTION OF THE INVENTION
Next, embodiments of the present invention will be described with reference to the drawings.
[0017]
FIG. 1 shows the configuration of an apparatus for executing a program download method according to the present invention. This apparatus has a configuration in which a row counter 70 is added to the conventional example shown in FIG.
[0018]
According to the program download method of the present invention, the CPU 30 having the function of reading the file from the medium 20 on which the download file is written and receiving the data from the PC 10 via the serial controller 60. The CPU 30 receives the data transferred from the serial controller 60 and stores the received data in the RAM 50 while counting the number of rows of data received from the PC 10 by the row number counter 70. At the end of reception of all data, the count result of the row counter 70 is compared with data of the total number of rows of received data transmitted from the PC 10, and if they match, the flash memory is instructed by the flash memory update instruction from the PC Written in memory 40 To erase the data, and writes the data stored in the RAM50.
[0019]
Next, the operation of the CPU 30 and the like will be described in more detail with reference to FIGS. 1 and 3 to 5.
[0020]
First, a download file is prepared on the medium 20. Here, a case where an Intel hexa format file is prepared as a download file will be described as an example.
[0021]
When this file is prepared, the total number of lines transmitted by the PC 10 can be calculated and the total number of lines can be added and transmitted (when the software is already installed). There is no need to add data. If you do not have the function to calculate the total number of lines sent by the PC 10 and add the total number of lines to send data (no software installed), download the file. It is necessary to add data for the total number of rows to the in advance.
[0022]
Next, the PC 10 transmits a download start command to the CPU 30. The CPU 30 does not accept a download from the PC 10 unless it receives a download start command from the PC 10.
[0023]
When the CPU 30 receives a download start command from the PC 10 via the serial controller 60 (FIG. 3, Step 1), the CPU 30 initializes the RAM 50 for storing the received download file and the line number counter 70, and receives the download file. Is prepared (FIG. 3, Step 2).
[0024]
Here, the initialization of the RAM 50 is to write data in the same state as when the flash memory 40 to be updated is erased. For example, if the state after erasure of the flash memory 40 is 0xFF, the RAM 50 is initialized with 0xFF, and if the state after erasure of the flash memory 40 is 0x00, the RAM 50 is initialized with 0x00.
[0025]
In this way, by initializing the RAM 50 for storing the received download file, when the data stored in the RAM 50 matches the data in the RAM 50 when the data stored in the flash memory 40 is written, the writing is performed. By performing such a process (FIG. 5, Step 5), not only the update process time of the flash memory 40 is reduced, but also the lifetime of the flash memory 40 is extended by not performing extra writing to the flash memory 40. There is an effect that it becomes possible.
[0026]
When the preparation for receiving the download file is completed, the CPU 30 returns a response to the download start command to the PC 10 via the serial controller 60 (FIG. 3, Step 3).
[0027]
When the PC 10 receives a response to the download start command from the CPU 30, the PC 10 reads data from the medium 20 in which the download file is written and starts transmitting data.
[0028]
The CPU 30 receives data from the PC 10 to the new line ('\ n') code, that is, data for one line of the download file in the Intel hexa format via the serial controller 60 (FIG. 3, Steps 4 to 5). ).
[0029]
When the CPU 30 receives the data for one line, the CPU 30 calculates the sum of the received data (FIG. 3, Step 6), and compares it with the checksum code added to each line in the Intel hex format to confirm that the correct data has been received. Whether or not is determined (FIG. 3, Step 7).
[0030]
At this time, if the checksum codes do not match, it means that the correct data could not be received. Therefore, the received data is discarded and the PC 10 is notified that an abnormality in the received data has been detected (FIG. 3). , Step 11). Conversely, if the checksum codes match, it means that correct data has been received, and therefore it is determined which record type data in the Intel hexa format has been received (step 8, FIG. 3).
[0031]
Here, the operation is performed as follows according to the record type of the received data.
[0032]
When the data of the start address record indicating the entry point address is received, the data is discarded without being stored in the RAM 50, the address for storing the next transmitted data is calculated, and the count of the row number counter 70 is counted. The value is added to wait for data (FIG. 4, Steps 1 to 4).
[0033]
When the data of the extended address record indicating the paragraph value of the load address is received, the data is discarded without being stored in the RAM 50, the address for storing the next data to be sent is calculated, and the row number counter The count value of 70 is added to wait for data (FIG. 4, Steps 5 to 8).
[0034]
When data of the data record indicating the code value is received, the necessary data is extracted, stored in the RAM 50 download data storage area, the count value of the row counter 70 is added, and then sent. Wait for the data to be received (FIG. 4, Steps 9 to 12).
[0035]
When data of an end record indicating the end of the code is received, the data is discarded without being stored in the RAM 50, the count value of the line number counter 70 is added, and the total number of lines sent next is counted. Wait for data (FIG. 4, Steps 13 to 16).
[0036]
When the CPU 30 finishes the process corresponding to the data record, it reports to the PC 10 that the received data is normal (FIG. 4, Step 18). The normal report can be omitted.
[0037]
The PC 10 reads the file from the medium 20 and transmits the data until transmission of all data is completed (waits for a normal response from the PC 10 and if there is a response), and also reads the data from the medium 20 and stores the data. The process of transmitting (waiting for a normal response from the PC 10) is repeated.
[0038]
The CPU 30 also repeats the process of storing the received data in the area for storing the download data in the RAM 50 until the reception of all the data is completed (FIG. 3, Steps 4 to 9).
[0039]
When the PC 10 has a function capable of calculating the total number of lines transmitted and adding the total number of lines to be transmitted, the PC 10 transmits a new line ('\ n') code after transmitting the end record of the file. Is transmitted, that is, the number of transmitted lines is transmitted.
[0040]
On the other hand, if the PC 20 does not have a function for calculating the total number of lines transmitted and transmitting the total number of lines of data, since the total number of lines of data is added to the media 20 in advance, Send data.
[0041]
The PC 10 transmits all the data written in the medium 20 (and the data of the number of lines transmitted), and updates the flash memory 40 if there is no response (report) of abnormal data reception from the CPU 30. A flash memory update command is transmitted to the CPU 30.
[0042]
When the CPU 30 receives a flash memory update command from the PC 10 via the serial controller 60 (FIG. 5, Step 1), the CPU 30 erases the flash memory 40 and confirms whether or not the flash memory 40 has been erased (FIG. 5, Steps 2-3) If the flash memory 40 has been erased, the process proceeds to the next step. If the flash memory 40 has not been erased, an abnormal end of the flash memory update process is detected via the serial controller 60. It notifies to PC10 and complete | finishes (FIG. 5, Step10).
[0043]
Next, the data stored in the RAM 50 is read out and compared with the data in the flash memory 40 (FIG. 5, Steps 4 to 5). If they do not match, the data is written into the flash memory 40 and stored in the flash memory 40. It is confirmed whether or not writing has been performed normally (FIG. 5, Steps 6 to 7). If writing to the flash memory 40 is successful, the process proceeds to the next step, and writing to the flash memory 40 has not been performed. In this case, the abnormal end of the flash memory update process is notified to the PC 10 via the serial controller 60 and the process ends (FIG. 5, Step 10).
[0044]
If the writing to the flash memory 40 has been normally completed, it is confirmed whether or not the writing of all data has been completed (FIG. 5, Step 8). Is completed by notifying the PC 10 via the serial controller 60 (FIG. 5, Step 9). If all the data has not been written, the process returns to the previous step to write to the flash memory 40. Is repeated (FIG. 5, Steps 4 to 7).
[0045]
In the description of this operation, the file format initially prepared in the medium 20 is the Intel hexa format file, but it can be realized by other format files such as the S format. Although an embodiment in hardware is shown, it can also be realized by software.
[0046]
Next, a second embodiment of the program download method according to the present invention will be described with reference to FIG.
[0047]
In this apparatus, a sum calculation circuit 80 is further added to the configuration shown in FIG.
[0048]
In a configuration in which a PC 10 having a function of reading a file from a medium 20 in which a download file is written and transmitting data is connected to a CPU 30 having a function of receiving data from the PC 10 via a serial controller 60, the CPU 30 has a serial interface. The received data is stored in the RAM 50 while receiving the data transferred from the controller 60 and counting the number of rows of data received from the PC 10 by the row number counter 70. The count result is compared with the data of the total number of received data transmitted from the PC 10, and if they match, the sum of the data stored in the RAM 50 is calculated by the sum calculation circuit 80 according to the flash memory update instruction from the PC 10. Flash memory And erasing data written in 0, and writes the sum calculated by the data and the checksum calculation circuit 80 stored in the RAM 50.
[0049]
Next, the operation of the CPU 30 and the like will be described. The procedure (FIG. 3, Step 1) (FIG. 4, Step 1) until the CPU 30 receives the download file from the PC 10 is the same as the implementation procedure described above. Therefore, the flash memory update processing after data is normally received will be described with reference to FIG.
[0050]
If there is no response (report) for receiving abnormal data from the CPU 30, the PC 10 transmits a flash memory update command to the CPU 30 in order to update the flash memory 40.
[0051]
When the CPU 30 receives a flash memory update command from the PC 10 via the serial controller 60 (FIG. 6, Step 1), the sum calculation circuit 80 causes the sum of the area of the RAM 50 storing the received download file, that is, the flash memory 40 The sum of the program update area is calculated, and the sum is written in the RAM 50 corresponding to the thumb storage area of the flash memory 40.
[0052]
The subsequent flash memory 40 erasure to update end response processing (FIG. 6, Steps 2 to 10) is the same as the implementation procedure described above, and the updated flash memory 40 includes the flash memory calculated in the previous step. 40 sums are written.
[0053]
Here, by writing the sum into the flash memory 40, it is possible to perform the self-diagnosis (sum check) by calculating the sum of the program area at the time of starting the apparatus or / and at regular intervals.
[0054]
In the description of this operation, the thumb calculation circuit 80 is shown as an embodiment in hardware, but it can also be realized by software.
[0055]
【The invention's effect】
As described above, according to the present invention, it is possible to provide a program download method capable of improving the reliability of received data, speeding up transmission / reception processing, and simplifying the device configuration. Become.
[Brief description of the drawings]
FIG. 1 is a block diagram showing a first embodiment of a program download method according to the present invention.
FIG. 2 is a block diagram showing a second embodiment of the program download method according to the present invention.
FIG. 3 is a flowchart showing a first embodiment of a program download method according to the present invention.
FIG. 4 is a flowchart showing a first embodiment of a program download method according to the present invention.
FIG. 5 is a flowchart showing a first embodiment of a program download method according to the present invention.
FIG. 6 is a flowchart showing a second embodiment of the program download method according to the present invention.
FIG. 7 is a block diagram showing an example of a conventional program download method .
FIG. 8 is a block diagram showing an example of a conventional program download method .

Claims (1)

A program download method for transmitting an Intel hexa format or S format program file from one device and downloading the program file to the other device,
In the one device, information on the total number of lines of the program file is added and the file is transmitted,
In the other device,
While the received program file is stored in the RAM, a sum check process is performed for each line of the received program file, and the number of lines of the received program file is counted and compared with the added total number of lines. ,
When the result of the sum check process indicates that the correct data has been received, and when the counted number of rows and the added total number of rows match, it is determined that there is no error in the received data, and A program download method for writing a program file stored in a RAM into a nonvolatile memory.

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