JP2012190075A - Update difference data creation device, data update system and update difference data creation program - Google Patents

Abstract

PROBLEM TO BE SOLVED: To promptly execute data rewriting processing.SOLUTION: An update difference data creation device 20 executes: a step for, when an S byte of small data capacity and an L byte of large data capacity are available as block sizes, calculating a block quantity BN_S in update difference data when the block size is set at the S byte, and a block quantity BN_L in the update difference data when the block size is set at the L byte; a step for extracting disparity data on an S-byte basis when a formula, BN_S×(T_se+(T_bp×S/WS))<BN_L×(T_be+(T_bp×L/WS)), holds; and a step for creating the update difference data. BN_S represents the block quantity in the update difference data when the block size is set at the S byte, BN_L represents the block quantity in the update difference data when the block size is set at the L byte, T_se represents S-byte data erasing time of a flash memory, T_be represents L-byte data erasing time of the flash memory, T_bp represents per-word data writing time of the flash memory, and WS represents a per-word byte quantity.

Description

  The present invention relates to an update difference data creation device, a data update system, and an update difference data creation program, and more specifically, an old version data recorded in a FLASH memory or an SD card is quickly replaced with a new version data with less update data. The present invention relates to an update difference data creation device, a data update system, and an update difference data creation program that can be updated.

  In recent years, car navigation systems that display a map image on a display and provide route guidance to a destination have become widespread.

  In a car navigation system, in order to improve the accuracy of route guidance, it is desirable to keep as new map information as possible in the car navigation system. In addition, today's car navigation system is not only a route guidance process, but also an in-vehicle audio device for operating and reproducing music recorded on a CD, MD, etc., a DVD, a Blu-ray Disc (registered trademark), etc. Many of them have a function as a video playback device for playing back video. For this reason, it is necessary to add a function corresponding to the user's needs by updating the system as necessary.

  In order to update such map information and system information, a recording medium (for example, CD-ROM or DVD-ROM) on which the latest map information or system information is recorded is used. Many methods of updating map information and system information are used (see, for example, Patent Document 1).

  However, when updating map information and system information in this way, it is necessary to perform update processing by erasing all of the old information and then writing new information. There was a problem that it was needed.

  For this reason, instead of updating all map information etc., only newly updated map information and system information are updated from old data to new data, and the data contents have changed between the new data and old data. A difference update processing method is known in which no update processing is performed on data that is not changed (that is, data that has not been changed).

  In this differential update processing method, in general, the contents of the data recording unit of the car navigation system are determined as a set of a plurality of file data (partially grouped data), and only the updated file data is determined. A method is used in which file data that has been changed and not updated is used without being updated.

  However, even with updated file data, not all data constituting the file data is updated, and only a part of the data in the file data is subject to update. For this reason, there is also a method of using the case of updating the data by creating the update difference data for each file data and updating the data using the entire file data as needed. It has been proposed (see, for example, Patent Document 2).

  In the method disclosed in Patent Document 2, a data area to be updated in the car navigation system is extracted for each file data (in FIG. 4 of Patent Document 2, files 1 to 4 are illustrated) and extracted. The amount of difference data relative to the amount of file data obtained is calculated, the size rate of the difference data is calculated, and the data is updated using the difference data of the corresponding file data only when the size rate is smaller than the predetermined ratio. When the size ratio is larger than the predetermined ratio, a method of updating the data as a whole is employed by using new file data.

Japanese Patent Laid-Open No. 2003-337027 JP-A-2006-251768 (FIGS. 2 to 4)

  Incidentally, Patent Document 2 exemplifies a case where information is updated by recording update data on a recording medium such as a DVD and reading the update data with a car navigation system. However, in the method of recording update data on a recording medium such as a DVD, it has been difficult to frequently provide update data. Actually, when update data is recorded on a DVD or the like and provided, there has been a problem that the frequency of supply becomes about once every one to two years.

  On the other hand, from the viewpoint of a user who uses a car navigation system, there is a desire to update information to new map information as soon as possible. For this reason, today, a method has been proposed in which a car navigation system is accessed to a server using a communication line such as a mobile phone line, and when data is updated, the data is updated quickly.

  When update data is acquired using a communication line in this way, it is preferable to update map information or the like using as little data as possible in order to reduce communication costs and data download time. . However, since data such as map information has a relatively large amount of information, if the map information is updated using only a communication line, there is a risk that convenience may be impaired due to an increase in received data amount and download time.

  For this reason, when updating in units of file data, update is performed using information recorded on a recording medium such as a DVD. When updating is performed in units of data smaller than one file data, the difference data is stored using a communication line. There has been proposed a method of performing data update processing by acquiring the data.

  On the other hand, by updating the data using the difference data, it is possible to reduce the data amount of data transmitted and received via the communication line, but using a method of frequently updating a small amount of data, Since the number of times of writing data to a recording medium for recording map information or the like increases, the update process tends to take time.

  Particularly in recent years, in car navigation systems, the number of models that record map information and system information in a nonvolatile memory such as a FLASH memory and an SD card has increased. In a car navigation system that records data in a non-volatile memory, the time required for data erasing / writing processing tends to be longer than when a hard disk drive is used.

  For this reason, if the process of frequently updating only updated data blocks using the difference data is performed, it takes time instead of the update process, and further, the number of rewrites increases, leading to a reduction in memory life. There was a problem that there was a risk of being.

  The present invention has been made in view of the above problems, and an update difference data creation device, a data update system, and an update that can quickly perform a rewrite process of data recorded on a recording medium (a FLASH memory or an SD card). It is an object to provide a differential data creation program.

  In order to solve the above-described problem, an update difference data creation device according to the present invention includes update information in which an old version of data recorded in a FLASH memory and a newer version of data than the old version of data are recorded. The block size is defined as the data capacity that can be erased by the erasing process for each time in the recording means and the FLASH memory, and the new version data and the old version data recorded in the update information recording means are compared. An update difference data creating means for creating update difference data by extracting the data of different parts of the data content as the difference data in the block size unit, and combining the extracted difference data in the block size unit; The update difference data creation means is an S-bye having a small data capacity. And L bytes having a large data capacity can be used as the block size of the FLASH memory, the number of blocks BN_S of the update difference data when the block size is S bytes, The block number BN_L of the update difference data when the block size is set to L bytes is calculated, and when the following formula is satisfied, the difference data is extracted in S bytes, which is the small data capacity, and the update difference data is extracted. When the following formula is not satisfied, the difference data is extracted in units of L bytes, which is the large data capacity, and the update difference data is generated.

  However, the formula is BN_S × (T_se + (T_bp × S / WS)) <BN_L × (T_be + (T_bp × L / WS)), where BN_S is the update difference data when the block size is S bytes. The number of blocks, BN_L is the number of blocks of the update difference data when the block size is L bytes, T_se is the time required to erase S bytes of data in the FLASH memory, and T_be is Time required for erasing data of L bytes in the FLASH memory, T_bp is a time for writing data of one word in the FLASH memory, and WS is the number of bytes per word in the FLASH memory. The T_se, T_be, T_bp, and WS data for the FLASH memory are recorded in advance in the update information recording means.

  The update difference data creation device according to the present invention includes an update information recording unit in which data of an old version recorded on an SD card and data of a newer version than the data of the old version are recorded, and the SD The data capacity that can be erased by each erasing process in the card is defined as a block size, and a new version of data recorded in the update information recording means is compared with an old version of data, and different data contents Update data creation means for creating update difference data by extracting the difference data in the block size unit as a difference data and combining the extracted difference data in the block size unit, the block size of the SD card If it is possible to use multiple data capacity as For each block size BS having a different data capacity, the update information recording means stores the new version based on the write throughput Wth (BS) of the SD card, the read throughput Rth (BS) of the SD card, and update difference data. Patch processing throughput Pth (BS) of the patch processing for creating the data of the update difference is created, and the update difference data creation means is the update information recording means when the data amount of the update difference data is D (BS). Read a plurality of write throughputs Wth (BS), a plurality of read throughputs Rth (BS), and a plurality of patch processing throughputs Pth (BS) recorded for each block size BS, and D (BS) / (Wth ( BS) + Rth (BS) + Pth (BS)) Seeking Kusaizu the BS, and wherein the creating the update difference data by extracting the difference data in the block size BS units.

  Here, the write throughput indicates the number of block sizes of data that can be written per unit time, the value changes according to the number of bytes set as the block size, and the SD card hardware characteristics It has the property that the value differs depending on

  The read throughput indicates the number of block sizes of data that can be read per unit time. The value changes according to the number of bytes set as the block size. It has the property that the value is different depending on it.

  Further, the patch processing throughput refers to the creation of a new version of data per unit time when creating a new version of data based on the old version of data and update difference data recorded on the SD card. The number of possible block sizes is shown, and a value approximated to the memory copy throughput between a DRAM (SDRAM or the like) used for patch processing and an SD card is shown.

  Further, the data update system according to the present invention defines a FLASH memory in which an old version of data is recorded, and a data capacity that can be erased by each erasing process in the FLASH memory as a block size. Update difference data created by extracting and combining data of different data contents between the data and the new version data as difference data in units of the block size, and the old version recorded in the FLASH memory New version data generating means for generating new version data based on the data, memory data erasing means for erasing the data in the FLASH memory in block units, and the memory data erasing means erased by the memory data erasing means In the FLASH memory area, Data writing means for writing new version data generated by the version data generating means, and outputting the version information of the old version to a server via a network line, and the update difference data via the network line A client having client communication means that can be received from the server, update information recording means in which all versions of data that can be recorded in the FLASH memory are recorded, and the version information output by the client communication means Corresponding to the version information received by the server communication means and the server communication means capable of outputting the update difference data to the client via the network line. The version data is acquired from the data recorded in the update information recording means, and the difference data is extracted by comparing the acquired version data with the new version data recorded in the update information recording means. And a server having update difference data creation means for creating update difference data, wherein the update difference data creation means stores S bytes having a small data capacity and L bytes having a large data capacity as described above. When it can be used as the block size of the FLASH memory, the number of blocks BN_S of the update difference data when the block size is set to S bytes and the update difference when the block size is set to L bytes The number of data blocks BN_L is calculated, and when the following formula is true, The difference data is extracted in units of S bytes to create the update difference data, and if the following formula is not satisfied, the difference data is extracted in units of L bytes that are the large data capacity to create the update difference data The server communication means outputs the update difference data created by the update difference data creation means to the client, and the client communication means receives the update difference data outputted by the server. The new version data generation means generates new version data based on the update difference data received by the client communication means and the old version data recorded in the FLASH memory, and the memory The data erasure means is the update difference received by the client communication means. Based on the block size constituting the data, the data in the FLASH memory is erased in units of the block size, and the data writing means stores the new version data in the area of the FLASH memory erased by the memory data erasing means. The new version data generated by the generating means is written in units of the block size.

  However, the formula is BN_S × (T_se + (T_bp × S / WS)) <BN_L × (T_be + (T_bp × L / WS)), where BN_S is the update difference data when the block size is S bytes. BN_L is the number of blocks of the update difference data when the block size is L bytes, T_se is the time required to erase S bytes of data in the FLASH memory, and T_be is , Time required for erasing L bytes of data in the FLASH memory, T_bp is a time for writing data of one word in the FLASH memory, and WS is the number of bytes per word in the FLASH memory The T_se, T_be, T_bp, and WS data for the FLASH memory are recorded in advance in the update information recording means.

  Further, the data update system according to the present invention defines an SD card in which an old version of data is recorded, and a data capacity that can be erased by each erasing process in the SD card as a block size. The update difference data created by extracting and combining data of different data contents in the data and the new version data as difference data in units of the block size, and the old version recorded on the SD card New version data generating means for generating new version data based on the data, data writing means for writing the data of the SD card in units of the block size, and the version information of the old version via a network line Output to the server and update A client having client communication means capable of receiving minute data from the server via the network line; update information recording means in which all versions of data that can be recorded on the SD card are recorded; Server communication means capable of receiving the version information output by the client communication means via the network line and outputting the update difference data to the client via the network line, and the server communication means The version data corresponding to the version information received by the data is acquired from the data recorded in the update information recording means, the acquired version data and the new version data recorded in the update information recording means, To extract the difference data And a server having update difference data creation means for creating update difference data, and when it is possible to use a plurality of data capacities as the block size of the SD card, the update information recording means In addition, for each block size BS having a different data capacity, the data of the new version is created based on the write throughput Wth (BS) of the SD card, the read throughput Rth (BS) of the SD card, and the update difference data. When the patch processing throughput Pth (BS) of the patch processing to be recorded is recorded, and the data amount of the update difference data is D (BS), the update difference data creation unit stores the block size BS in the update information recording unit. Multiple write throughputs Wth (BS) recorded for each and multiple read throughputs A block size BS that reads the embedded throughput Rth (BS) and a plurality of patch processing throughputs Pth (BS) and minimizes the value of D (BS) / (Wth (BS) + Rth (BS) + Pth (BS)). The update difference data is created by extracting the difference data in units of the block size BS, and the server communication means sends the update difference data created by the update difference data creation means to the client. The client communication means receives the update difference data output by the server, and the new version data generation means includes the update difference data received by the client communication means, and the SD card. Based on the old version data recorded in the Generates over data, the data writing means, the data of the new versions generated in the new version data generation means, and writes the SD card in the block size of the update difference data

  Further, the update difference data creation program according to the present invention includes an update information recording means in which an old version of data recorded in the FLASH memory and a newer version of data than the old version of data are recorded, and the FLASH A data capacity that can be erased by each erasing process in the memory is defined as a block size, and a new version of data recorded in the update information recording means is compared with an old version of data, and different data contents In the update difference data creation device comprising: update difference data creation means for extracting the difference data in the block size unit and creating the update difference data by combining the extracted difference data in the block size unit The update difference data creation means An update difference data creation program for creating difference data, wherein the update difference data creation means sets S byte having a small data capacity and L bytes having a large data capacity as the block size of the FLASH memory. When the block size is set to S bytes, the number of blocks BN_S of the update difference data when the block size is set to S bytes and the number of blocks BN_L of the update difference data when the block size is set to L bytes are used. Calculating the number of blocks to be calculated; and when the following formula is satisfied, the difference data is extracted in S bytes, which is the small data capacity, to create the update difference data, and when the following formula is not satisfied, the large data The difference data is extracted in units of L bytes, which is the capacity, and the update difference data is created. It is a program for executing the update difference data creation step to be created.

  However, the formula is BN_S × (T_se + (T_bp × S / WS)) <BN_L × (T_be + (T_bp × L / WS)), where BN_S is the update difference when the block size is S bytes. The number of data blocks, BN_L is the number of blocks of the update difference data when the block size is L bytes, T_se is the time required for erasing S bytes of data in the FLASH memory, and T_be Is a time required for erasing L bytes of data in the FLASH memory, T_bp is a writing time of data of one word in the FLASH memory, and WS is a byte per word in the FLASH memory. The T_se, T_be, T_bp, and WS data for the FLASH memory are recorded in advance in the update information recording means.

  The update difference data creation program according to the present invention records an old version of data recorded on an SD card and data of a newer version than the old version of data, and further, once in the SD card. The data capacity that can be erased by each erasing process is defined as a block size, and when a plurality of data capacities can be used as the block size of the SD card, the SD card is recorded for each block size of different data capacity Card write throughput Wth (BS), SD card read throughput Rth (BS), and patch processing throughput Pth (BS) of patch processing for creating the new version data based on update difference data are recorded. Recorded update information recording means and the update information recording means. Comparing the new version of the data with the old version of the data, extracting data of different parts of the data contents as the difference data in the block size unit, and combining the extracted difference data in the block size unit In the update difference data creation device comprising update difference data creation means for creating update difference data by the update difference data creation program for causing the update difference data creation means to create the update difference data, In the difference data creation means, when the data amount of the update difference data is D (BS), a plurality of write throughputs Wth (BS) recorded for each block size in the update information recording means and a plurality of read throughputs Rth (BS) and multiple patch processing through A minimum block size calculating step of reading a block Pth (BS) and obtaining a block size BS that minimizes the value of D (BS) / (Wth (BS) + Rth (BS) + Pth (BS)); It is a program for executing the update difference data creating step for creating the update difference data by extracting the difference data in units of the block size BS calculated in the minimum block size calculating step. .

  In general, the FLASH memory cannot overwrite and store data, and therefore it is necessary to write updated data after erasing data once. Furthermore, since data cannot be erased in units of 1 byte in FLASH memory, it is necessary to write updated data after erasing data in units of a predetermined block size.

  Therefore, in the update difference data creation device, the data update system, and the update difference data creation program according to the present invention, the data capacity that can be erased by each erase process in the FLASH memory is defined as a block size, and a new version of data The update difference data is created by comparing the old data and the old version data, and extracting and combining the data with different data contents in the unit of the block size as the different data. By creating update difference data in this way, it is possible to create update difference data suitable for FLASH memory update processing.

  Further, the data capacity that can be erased by the erase process for each time in the FLASH memory is not necessarily limited to one data capacity, and any one of a plurality of types of data capacity is selected as a block size and selected. In some cases, it is possible to erase data based on the block size.

  In this way, when it is possible to select the data capacity of a block size that can be erased by each erase process, depending on whether or not the difference data is extracted and the update difference data is created in units of the block size, There may be a difference in the update processing time of the FLASH memory.

  In general, the data erasing time in the FLASH memory tends to not cause a difference in erasing time even if there is a difference in data capacity to be erased at one time. For this reason, when erasing the same data capacity, increasing the block data can reduce the number of times of erasure processing compared to reducing the block data. Is possible.

  On the other hand, the data writing time tends to take much time in proportion to the number of data writing processes. Therefore, when the block size is increased, there is a higher possibility that different data contents will be included in one block size in the old and new versions, and the number of different data to be extracted increases compared to the case where the block size is small. Tend. Therefore, when the block size is increased and the number of different data to be extracted is increased, the number of times of writing the update difference data to the FLASH memory is increased, and the write processing time is generally increased. There's a problem.

In the update difference data creation device, the data update system, and the update difference data creation program according to the present invention, it is possible to use S bytes having a small data capacity and L bytes having a large data capacity as the block size of the FLASH memory. If possible, the block number BN_S of the update difference data when the block size is S bytes and the block number BN_L of the update difference data when the block size is L bytes are calculated, and the hardware characteristics of the FLASH memory T_se (time required for erasing data of S bytes in the FLASH memory) determined based on T_be (time required for erasing data of L bytes in the FLASH memory), T_bp (time for writing data for one word in FLASH memory), WS (FLA By using the number of bytes per word in SH memory)
BN_S × (T_se + (T_bp × S / WS)) <BN_L × (T_be + (T_bp × L / WS))
It is determined whether or not

  Here, T_se in the above formula is the erasure processing time of S bytes of data, which is a small data capacity in the FLASH memory, and (T_bp × S / WS) is the write processing time of data of S bytes in the FLASH memory, T_be represents the erasure processing time of L bytes of data, which is a large data capacity in the FLASH memory, and (T_bp × L / WS) represents the write processing time of L bytes of data in the FLASH memory.

  Therefore, the above formula corresponds to a comparison of the sum of the data erase time and the write time based on the difference in block size. If the formula is satisfied, the data update of the FLASH memory is performed with the S byte as the block size. When processing, the processing time is shortened compared to performing data update processing with L bytes as the block size, and when the expression does not hold, the data updating processing with L bytes as the block size is performed using S bytes. As a block size, it can be determined that the processing time is shorter than when the data update process is performed.

  By determining the block size in this way, the block size of the update difference data used for the data update process of the FLASH memory can be optimized, the data update process can be accelerated, and the data amount of the update difference data Reduction can be realized.

  An SD card is also a kind of FLASH memory, and is common to FLASH memory in that it is necessary to erase old data and then write new data before writing data. For this reason, even in the SD card, the data capacity that can be erased by each erase process is defined as the block size.

  In general, an SD card is provided with a controller for performing data update (erase / read / write) control, and data is erased / read / write by the controller. However, if the block size for updating the data is different, the data update processing time is different even for the same SD card.

  In the update difference data creation device, the data update system, and the update difference data creation program according to the present invention, when a plurality of data capacities can be used as the block size of the SD card, for each block size of different data capacities SD card write throughput Wth (BS), SD card read throughput Rth (BS), and patch processing throughput Pth (BS) of patch processing for creating new version data based on the update difference data, It is recorded in the update information recording means.

  The update difference data creation means of the update difference data creation device, the data update system, and the update difference data creation program according to the present invention includes a block size in the update information recording means when the data amount of the update difference data is D (BS). A plurality of write throughputs Wth (BS), a plurality of read throughputs Rth (BS), and a plurality of patch processing throughputs Pth (BS) recorded for each are read out, and D (BS) / (Wth (BS) + Rth ( A block size BS that minimizes the value of (BS) + Pth (BS)) is obtained, and difference data is extracted in units of the block size BS, thereby creating update difference data.

  By creating the update difference data in this way, it is possible to obtain a block size that can reduce the combination of write time, read time, and patch processing time, which differs depending on the block size in the SD card, most. Become. By extracting the difference data in units of the block size and creating the update difference data, the block size of the update difference data used for the SD card data update process can be optimized, and the data update process can be accelerated. In addition, it is possible to reduce the amount of update difference data.

It is the figure which showed the state by which the car navigation system and server which concern on this Embodiment were connected via the network line. 1 is a block diagram showing a schematic configuration of a car navigation system according to the present embodiment. It is a figure for demonstrating the data recording structure of the data recording part which concerns on this Embodiment. It is the block diagram which showed schematic structure of the server which concerns on this Embodiment. It is the timing chart which showed transmission / reception of the information between the car navigation system which concerns on this Embodiment, and a server. It is the flowchart which showed the data update process performed by CPU of the car navigation system concerning this Embodiment. It is the flowchart which showed the data update process performed by server CPU of the server which concerns on this Embodiment. It is a figure for demonstrating the procedure which produces update difference data in server CPU of the server which concerns on this Embodiment.

  Hereinafter, an update difference data creation device according to the present invention will be described in detail with reference to the drawings, showing a server which is an example of an update difference data creation device and a car navigation system connected to the server via a network line. explain.

  FIG. 1 is a diagram showing a car navigation system (client) 1 and a server (update difference data creation device, server) 20 according to the present embodiment. As shown in FIG. 1, the car navigation system 1 and the server 20 are connected via a network line 30. Specifically, the car navigation system 1 is mounted on the vehicle 2 and can be connected to the network line 30 via a mobile phone line as will be described later. On the other hand, the server 20 is also connected to the network line 30, and the car navigation system 1 and the server 20 can transmit and receive data via the network line 30.

  The network line 30 may be a network that is widely open to third parties such as the Internet, or may be a network that imposes certain restrictions on network access, such as a LAN. . Furthermore, the connection to the network line 30 in the car navigation system 1 is not necessarily limited to the mobile phone line, and may be a communication line such as Wi-Fi or WiMAX.

  Furthermore, although only one car navigation system 1 and one server 20 are shown in FIG. 1, the car navigation system 1 and the server 20 are not necessarily limited to one each. In general, many car navigation systems 1 exist via the network line 30, and each user can access the server 20 by using each car navigation system 1. Further, only one server 20 may be connected to the network line 30 or a large number of servers 20 may be connected.

[About car navigation system 1]
FIG. 2 is a block diagram showing a schematic configuration of the car navigation system 1. The car navigation system 1 includes a display unit 5, a touch panel unit 6, and a main body unit 10. The display unit 5 has a role of displaying surrounding map information and the like while traveling to the user during route guidance. Generally, a liquid crystal display is used for the display unit 5. In addition, the display unit 5 is provided with a speaker (not shown) or the like for outputting voice information during route guidance as required. In addition, this speaker is not limited to what is provided in the display part 5 directly, You may utilize the speaker for music installed in a vehicle.

  The touch panel unit 6 has a role of detecting a touch operation such as a menu icon displayed on the display unit 5. Information on the touch position of the user is transmitted to the CPU 15 to be described later, and the CPU 15 may determine the content of the user's operation based on the relationship between the touch position information and the display position of the menu icon displayed on the display unit 5. It is possible. In the present embodiment, a configuration for detecting a user's input operation using the touch panel unit 6 will be described. However, by using, for example, a keyboard, a joystick, an operation remote controller, or the like as an operation unit other than the touch panel unit 6, It may be configured to detect user input operations.

  The main unit 10 includes a communication unit (client communication unit) 11, a data recording unit (FLASH memory, SD card) 12, an SDRAM 13, an SD card read / write unit 14, a CPU (new version data generation unit, memory data erasing unit, Data writing means) 15. The communication unit 11 has a role of connecting to the network line 30. The communication unit 11 specifically corresponds to a network interface device using a cellular phone line (for example, CDMA (2G) system, W-CDMA (3G) system, HSDPS system, etc.). In response to an instruction (control command) from the CPU 15, the communication unit 11 outputs information on the car navigation system 1 described below to the server 20 and performs processing for acquiring data output from the server 20.

  In the data recording unit 12, system information and map information in the car navigation system 1 are recorded. As the data recording unit 12, a general auxiliary recording device such as a hard disk, an SSD (Solid State Drive), a FLASH memory, an SD card, or the like can be used. In the car navigation system 1 according to the present embodiment, a case where a FLASH memory is used as the data recording unit 12 will be described.

  The data recording unit 12 is assigned an address for indicating the recording position of the recorded data, as in a general auxiliary recording device, and judges the contents of the data by referring to this address. Is possible. In particular, in the data recording unit 12 according to the present embodiment, the type (data structure) of file data to be recorded is determined in advance for each address range having a predetermined capacity.

  For example, as shown in FIG. 3A, the file data A1 (data A1) is recorded in advance in the address range of addresses 1000 to 2000, and the file data B (data B) is recorded. The address range of addresses 0000 to 1000 is secured (defined), and the address range of addresses 2000 to 3000 is secured (defined) for recording of file data C (data C). Therefore, as in the case of the file data A1 (data A1) in FIG. 3A, the recorded file data A1 is recorded more than the reserved data capacity (data capacity corresponding to the range of addresses 1000 to 2000). When the data amount is smaller, empty data (for example, null data, for example) is stored in the data area from the last address of the file data A1 to the last address in the secured address range (up to address 2000 in the file data A1). ) Is recorded.

  For this reason, as shown in FIG. 3B, even when the file data A1 is updated to become file data A2 (data A2) and the data amount of the file data A2 increases, the empty data area is taken into consideration in advance. Since the address range of the file data A2 is secured, the file data A2 whose data amount is larger than the file data A1 is changed without changing the range (address range) from the start address 1000 to the end address 2000. Can be updated. Therefore, the file data B and file data C other than the updated file data A2 do not need to change the start address and the end address, and the file data recorded in the data recording unit 12 is used to update other file data. Along with this, it is possible to prevent the address range from being shifted and changed to a later address.

  The data recorded in the data recording unit 12 is 4 Kbytes as one block, and the CPU 15 manages the data for each block. In the data update process using update difference data described below, the CPU 15 performs a data update process (write process) in units of 8 Kbytes or 64 Kbytes, as will be described later. Details thereof will be described later.

  The data recording unit 12 according to the present embodiment uses the FLASH memory as described above. Since the FLASH memory cannot overwrite and store data, it is necessary to write updated data after erasing data once. Furthermore, since data cannot be erased in units of 1 byte in the FLASH memory, it is necessary to write updated data after erasing data in units of blocks.

  In the FLASH memory used in this embodiment, data can be erased every 8 Kbytes or every 64 Kbytes. However, in the data recording unit 12 according to the present embodiment, the time required for erasing data of 8 Kbytes in the FLASH memory and the time required for erasing data of 64 Kbytes are recorded in advance. . However, each data erasure time is almost the same time, and the erasure time does not change even if the amount of data erased by one erasure process is 8 Kbytes or 64 Kbytes. is doing.

  In the FLASH memory used in the present embodiment, two writings are performed: a Word-Program method for writing data in units of 1 word (2 bytes) and a Write Buffer Program method for writing in units of 16 words (32 bytes). Has a mode. In the conventional difference data update processing, the Word-Program method is often used, but the car navigation system 1 according to the present embodiment employs the Write Buffer Program method. By adopting the Write Buffer Program method, the amount of data that can be written at one time is larger than when using the Word-Program method, so the number of writes can be reduced and the write time is reduced to the Word-Program method. It becomes possible to reduce to 1/4 compared with the case of adopting.

  In addition to system information and map information, the data recording unit 12 includes ID information of the car navigation system 1 (information for identifying the car navigation system 1 for each device, and the serial number of the car navigation system 1 Information, identification number information, etc.) and version information of map information and system information recorded in the data recording unit 12 (the number of updates of map information and system information recorded in the data recording unit 12 by this version information, The specific data contents and the like can be specified by the server 20.) is recorded.

  The system information recorded in the data recording unit 12 includes programs for the CPU 15 to realize various functions in the car navigation system 1. As the program, for example, a program for the CPU 15 to perform route guidance, or a data update processing program for updating information recorded in the data recording unit 12 (for example, the program shown in the flowchart in FIG. 6). And so on. The CPU 15 executes various processes in the car navigation system 1 based on a program recorded in the data recording unit 12.

  The SDRAM 13 is a work area used when updating update difference data. The data capacity of the SDRAM 13 is smaller than that of the data recording unit 12. Since the data recording unit 12 according to the present embodiment uses the FLASH memory, the data in the data area of the FLASH memory to be updated is temporarily recorded in the SDRAM, and the recorded SDRAM data is updated and updated. Change to new data (update data) based on the data. Thereafter, after the CPU 15 erases the corresponding data area of the FLASH memory in a predetermined block unit, the data update of the data recording unit 12 is performed by writing new data recorded in the SDRAM to the FLASH memory. .

  The SD card read / write unit 14 has a role of reading and writing data recorded on the SD card. Specifically, the SD card read / write unit 14 updates the system information or map information of the data recording unit 12 for each file data, or updates all data of the data recording unit 12 from the SD card in which the update data is recorded. A process of reading out the necessary update data is performed. The SD card read / write unit 14 accesses the SD card based on an instruction (control command) from the CPU 15 and reads the necessary update data. The CPU 15 reads the update data read by the SD card read / write unit 14. A process of updating data in the data recording unit 12 is performed. The SD card read / write unit 14 can not only read information of the SD card but also write information as necessary. Furthermore, the use of the SD card read / write unit 14 is not limited to the case where the system information or the map information is read from the SD card and the data recording unit 12 is updated. For example, it is also possible to read music data recorded on an SD card and output it from a vehicle-mounted speaker, or to read out a video or image recorded on the SD card and display it on the display unit 5.

  The CPU 15 has a role of performing a route guidance process or a process of updating data in the data recording unit 12 according to a program recorded in the data recording unit 12. When the CPU 15 performs the route guidance process, the current position of the vehicle is acquired via a GPS antenna (not shown), and the vehicle traveling state (traveling direction) is further detected via a gyro (not shown) or a vehicle speed pulse detector. , Move speed, etc.). And CPU15 displays map information on the display part 5 based on the present position and driving | running | working state of the vehicle 2, and guides a driving | running route, an intersection name, etc. with audio | voice information as needed. The process in which the CPU 15 updates the data in the data recording unit 12 will be described later.

  Note that the program showing the processing content of the CPU 15 is not necessarily limited to the one recorded in the data recording unit 12. For example, a ROM or the like in which a program is recorded is prepared separately from the data recording unit 12 and the system 15 is started by the CPU 15 reading and executing the program recorded in the ROM when the car navigation system 1 is started. Is possible. Further, the CPU 15 includes a RAM (not shown) and the like, and the RAM is used as a work area for program processing.

[About the server 20]
Next, the server 20 will be described. FIG. 4 is a block diagram showing a schematic configuration of the server 20. The server 20 includes a communication unit (server communication unit) 21, an update information recording unit (update information recording unit) 22, a server CPU (update difference data creation unit) 23, a ROM 24, and a RAM 25.

  The communication unit 21 has a role of connecting to the network line 30. Specifically, it connects to the network line 30 using wired communication or wireless communication, and acquires and updates the ID information and version information of the car navigation system 1 in accordance with an instruction (control command) of the server CPU 23. The difference data is output to the car navigation system 1. The communication unit 21 corresponds to, for example, a general NIC (network interface card).

  The update information recording unit 22 is configured by a general auxiliary recording device such as a hard disk or an SSD. In the update information recording unit 22, the hardware configuration of the car navigation system 1 and various versions of update data (total update data, not partial update data) are recorded. For example, the car navigation system 1 has different functions that can be realized depending on the hardware configuration, and the data structure of the data recording unit 12 differs depending on the function based on the hardware configuration. Therefore, the server CPU 23 determines the data structure of the data recording unit 12 based on the ID information of the car navigation system 1 acquired via the communication unit 21. As described above, in the data recording unit 12, the data structure of file data to be recorded is determined for each address range having a predetermined capacity. For this reason, the server CPU 23 specifies the hardware configuration based on the ID information, so that the type (contents and role) of the file data recorded in the data recording unit 12 and the range from the start address to the end address (address range). Can be grasped.

  The update information recording unit 22 records various versions of data that can be recorded in the data recording unit 12. The server CPU 23 can determine the data content of the corresponding version information in the hardware configuration specified by the ID information and the data content of the latest update data by acquiring the version information from the car navigation system 1. It has become. Therefore, the server CPU 23 can create update difference data for updating data in the data recording unit 12 based on the acquired data contents of different versions.

  The ROM 24 is recorded with a program (for example, a program shown in a flowchart in FIG. 7) for causing the server CPU 23 to create a difference data. The server CPU 23 creates update difference data, which will be described later, based on a program recorded in the ROM 24. The RAM 25 is used as a work area in the update difference data creation process in the server CPU 23.

[About data update processing]
Next, data update processing in the car navigation system 1 and the server 20 will be described. In describing the data update process, an SD card is set in advance in the SD card read / write unit 14 of the car navigation system 1 in a state where data can be read, and the latest version of the data is stored in the SD card. Is recorded.

  FIG. 5 is a timing chart showing transmission / reception of information between the car navigation system 1 and the server 20. FIG. 6 shows a flowchart showing the data update process in the car navigation system 1, and FIG. 7 shows a flowchart showing the data update process in the server 20.

  First, the CPU 15 of the car navigation system 1 outputs ID information and version information to the server CPU 23 of the server 20 (step S.1). The CPU 15 outputs the ID information and the version information to the server CPU 23 to determine whether new update data exists for the server 20 (the system information and the map information recorded in the data recording unit 12 are the latest version). Whether it is information or not). Thereafter, the CPU 15 determines whether or not the reply information corresponding to the transmitted information has been received from the server CPU 23 (step S.2). If no reply information has been received (No in step S.2). In the case), the same processing is repeatedly executed until the reply information is obtained.

  The reply information is information obtained as a result of the determination by the server CPU 23 whether or not to update the data based on the ID information and the version information, and needs to be updated as will be described later. Information indicating that there is no information to be updated, information indicating that updating is required in units of file data, or update difference data in units of 8 Kbytes or 64 Kbytes.

  On the other hand, the server CPU 23 determines whether the ID information and the version information are received from the CPU 15 of any car navigation system 1 via the network line 30 (step S.31). The same process is repeated until the version information is received (if the result is No in step S.31, the reception determination process in step S.31 is repeated).

  When the server CPU 23 receives the ID information and the version information (Yes in step S.31), the car navigation system 1 that is the transmission source of the information is specified based on the ID information, and data recording is performed. The data structure of the unit 12 is determined (step S.32). Next, the server CPU 23 sends the latest version information and the information based on the received version information from the update information recording unit 22, which are system information and map information corresponding to the determined data structure of the data recording unit 12. Read out and extract the data difference (step S.33).

  Then, the server CPU 23 determines whether or not there is a data difference between the two pieces of information (step S.34), and if there is no difference (No in step S.34), Since the latest version of information is recorded in the data recording unit 12 for the car navigation system 1, information indicating that there is no information that needs to be updated is output to the CPU 15 of the car navigation system 1 ( Step S.35), the data update process is terminated.

  On the other hand, if there is a difference in data (Yes in step S.34), the server CPU 23 first determines whether or not there is a difference that needs to be updated in units of file data. (Step S.36) If the update is required in units of file data (Yes in Step S.36), the corresponding address and its data amount are extracted and the update information is recorded temporarily. It records in the part 22 (step S.37).

  Here, the case where the update is required in units of file data corresponds to, for example, a case where the amount of file data increases or decreases. As described above, in the data recording unit 12 of the car navigation system 1, the data structure of file data recorded in advance is determined for each address range having a predetermined capacity. Therefore, as described with reference to FIG. 3, the new version of the file data (for example, the data A2 illustrated in FIG. 3B) is compared with the old version of the file data (for example, the data A1 illustrated in FIG. 3A). When the amount of data increases (or decreases), it is necessary to perform processing for updating old file data to new file data based on the corresponding address. In such a case, the server CPU 23 determines that it is necessary to update in units of file data based on the difference in data, and records the corresponding address and data amount in the update information recording unit 22.

  When updating is not required in units of file data (No in step S.36), or after extracting an address for updating in units of file data and the amount of data (step S.37) The server CPU 23 determines whether or not it is necessary to create update difference data in consideration of the position (address) where the data is different and the continuity of the different data (step S). .38). For example, when the total data amount of the file data is increased or decreased, it is determined that there is no need to create update difference data because the entire file data is subject to update. On the other hand, if the total amount of file data does not increase or decrease, but only part of the data in the file data needs to be updated, update difference data is created based on this part of the data to be updated Judge that it is necessary.

  When it is determined that update difference data needs to be created (Yes in step S.38), the server CPU 23 extracts different data in units of 8 Kbytes to create update difference data. (Specifically, whether update difference data based on 8 Kbytes is created or update difference data based on 64 Kbytes is created) is determined (step S.39). The different data extracted here is referred to as difference data.

  Here, the data recording unit 12 of the car navigation system 1 is configured by a FLASH memory. For this reason, when updating the data recorded in the FLASH memory, first, it is necessary to erase the data at the address to be erased. Since this data can be erased every 8 Kbytes or every 64 Kbytes, when different data is extracted in units of 8 Kbytes to create update differential data, after erasing 8 Kbytes of data, When new update data is written only 8K bytes, and difference data is extracted in units of 64K bytes to create update difference data, 64K bytes of data are erased and then new update data is written only 64K bytes. Perform the process.

  The time required for updating the data in the data recording unit 12 differs depending on whether the server CPU 23 uses 8 Kbytes or 64 Kbytes as the basis for extracting the difference data in the update difference data. Specifically, in the data recording unit 12, if the data capacity for extracting the different data (the data capacity is set as the block size) can be reduced, the amount of data rewriting based on the different data can be reduced. Can be shortened. In other words, when the update process is performed with 8 Kbytes as the block size, the amount of data rewriting can be reduced and the data write time can be shortened compared with the update process with 64 Kbytes as the block size.

  However, as described above, when data is updated in the FLASH memory, it is necessary to perform a data write process after performing the erase process of the FLASH memory, and the time required for this erase process is 8 Kbytes. The same time is required regardless of whether the block size is erased or if 64 Kbytes are erased as the block size. For this reason, if the block size is reduced, the number of rewrite blocks in the FLAH memory increases, and the number of data erase increases as the number of rewrite blocks increases. As a result, a longer erase time is required than when the block size is large. There was a problem of becoming.

  The server CPU 23 refers to the number of blocks when determining the presence of a difference for each block size based on 8 Kbytes (hereinafter, a block that needs to be updated because the data contents are different is called a difference block. (The number of blocks is the number of difference blocks) and the number of blocks when judging the existence of a difference for each block size based on 64 Kbytes, and determining whether or not the following equation 1 holds: Do.

BN_8KB × (T_se + (T_bp × 8 × 1024 / WS))
＜ BN_64KB × (T_be + (T_bp × 64 × 1024 / WS)) ・ ・ ・ Equation 1
here,
BN_8KB is the number of difference blocks of update difference data when the block size is 8K bytes
BN_64KB is the number of differential blocks of update differential data when the block size is 64K bytes
T_se is the time required to erase 8K bytes of data in FLASH memory
T_be is the time required to erase 64 Kbytes of data in the FLASH memory
T_bp is the write time of data for one word in the FLASH memory (more specifically, the word programming time in the buffer programming mode of the FLASH memory)
WS is the number of bytes per word in FLASH memory (2 bytes for data recording unit 12)
Is shown.

  Since T_se, T_be, and T_bp are all data that depends on the FLASH memory, T_se, T_be, and T_bp related to the FLASH memory of the data recording unit 12 can be recorded in advance in the update information recording unit 22 of the server 20. . Therefore, when determining the hardware configuration of the car navigation system 1 based on the ID information, the server CPU 23 stores the T_se, T_be, and T_bp of the corresponding FLASH memory (in the data recording unit 12) in the update information recording unit 22. It can be determined based on the recorded data.

  Further, WS is 2 bytes, and BN_8KB and BN_64KB can be obtained with the extraction of the difference data. For this reason, it becomes possible for the server CPU 23 to determine whether or not Expression 1 is satisfied by substituting values corresponding to Expression 1 respectively.

  In Equation 1, T_se is the data erasure processing time for 8 Kbytes in the FLASH memory, (T_bp × 8 × 1024 / WS) is the data write processing time for 8 Kbytes in the FLASH memory, and T_be is the FLASH memory The data erasure processing time for 64 Kbytes in (T_bp × 64 × 1024 / WS) indicates the data write processing time for 64 Kbytes in the FLASH memory. Therefore, Equation 1 corresponds to a comparison of the sum of the data erasing time and the writing time based on the difference in block size, and when Equation 1 is satisfied, the method of performing data update processing based on 8 Kbytes. However, if the processing time is shortened compared to the case where the data update process is performed based on 64 Kbytes and Equation 1 is not satisfied, the data update process based on the 8 Kbytes is more effective when the data update process is performed based on 64 Kbytes. It can be determined that the processing time is shortened compared to

  When Expression 1 is satisfied (Yes in Step S.39), the server CPU 23 extracts difference data in units of 8 Kbytes and creates update difference data (Step S.40), and Expression 1 is not satisfied. In the case (No in step S.39), the difference data is extracted in units of 64K bytes to create update difference data (step S.41), and is temporarily recorded in the update information recording unit 22.

  FIG. 8 is a diagram for explaining a procedure for creating update difference data.

  The old version data recorded in the data recording unit 12 is indicated by old / rom1.bin, and the latest version data is new / rom1.bin. Each data is divided into unit blocks each having a block size of 8 Kbytes or 64 Kbytes as described above. The server CPU 23 determines whether or not there is a data difference for each block size, and if there is a difference even for a part of the data, the server CPU 23 detects an address for each corresponding unit block. In FIG. 8A, there is a difference (“02” in old / rom1.bin and “ff” in new / rom1.bin) in a part of the unit block indicated by the address 0001, and the address 0002 The case where a difference (“0a” in old / rom1.bin and “00” in new / rom1.bin) exists in a part of the unit block shown in FIG.

  As shown in FIG. 8B, the server CPU 23 extracts the addresses 0001 and 0002 of the corresponding unit block, and the old version data (old / 0001.rom1, old / 0002.rom1) and the latest version data (new / 0001.rom1, new / 0002.rom1) are taken, and the update difference data (pat / rom1.pat) is obtained as shown in FIG. create. In the update difference data, the address where the difference exists and the data content are recorded. This update difference data is created as a patch file, and the update difference data from which the difference data is extracted in block size and its address are recorded, so that the overall data amount can be reduced.

  Note that the method by which the server CPU 23 creates update difference data is not limited to the method described above. For example, as shown in FIG. 8B, when there is a difference between a part of the unit block indicated by the address 0001 and a part of the unit block indicated by the address 0002, the server CPU 23 corresponds. A new file may be created by combining the block data of unit block addresses 0001 and 0002, and an address list file relating to a block having a difference may be created.

  Thereafter, the server CPU 23 performs the above-described step S.E. for all addresses (all address ranges that can constitute file data). 36-S. 41 is checked (step S.42), and step S.41 is performed for all addresses. 36-S. Step S.41 is performed until the processing of Step S.41 is performed (Yes in Step S.42). 36-S. The process of 41 is repeated.

  Then, the server CPU 23 extracts the data differences at all addresses, and performs step S. 36-S. When it is determined that the processing of 41 has been performed (Yes in step S.42), it is necessary to update the created update difference data / file data in units of 8 Kbytes or 64 Kbytes Are read from the update information recording unit 22 that has been temporarily recorded and output to the CPU 15 of the car navigation system 1 (step S.43).

  When the CPU 15 receives the reply information (Yes in step S.2), the CPU 15 determines whether the reply information is information indicating that there is no information that needs to be updated (step S.3). ). When the reply information is information indicating that there is no information that needs to be updated (Yes in step S.3), the CPU 15 ends the data update process of the data recording unit 12.

  On the other hand, if the reply information is not information indicating that there is no information that needs to be updated (No in step S.3), the CPU 15 needs to update the reply information in units of file data. Whether or not the information is included is determined (step S.4). When the reply information includes information indicating that update is required in units of file data (Yes in step S.4), the CPU 15 updates the address information and data amount information to be updated from the corresponding information. And get. Then, the CPU 15 reads the data at the corresponding address from the SD card via the SD card read / write unit 14 and updates the information recorded in the data recording unit 12 (step S.5).

Since the data recording unit 12 of the car navigation system 1 according to the present embodiment is a FLASH memory, data can be written only after the FLASH memory is erased. Therefore, the update of information described in the data recording unit 12 is
(1) The information of the file data unit recorded on the SD card is read based on the address information and data amount acquired from the server CPU 23.
(2) Information read from the SD card is temporarily recorded in the SDRAM 13.
(3) The data recording unit 12 determines the address to be updated based on the address information acquired from the server CPU 23, and erases the data by the data amount corresponding to the data amount acquired from the address.
(4) The information recorded in the SDRAM 13 is read and recorded in the erased data recording unit 12.

  Data is updated through these four steps. By this processing, the update processing of the file data to be updated is performed so as to correspond to the address range having a predetermined capacity.

  When the reply information does not include information indicating that update is required in file data units (No in step S.4), or when data update processing is performed in file data units (step In S.5), the CPU 15 determines whether or not the update information includes update difference data in units of 8 Kbytes (step S.6).

  When the reply information includes update difference data in units of 8 Kbytes (Yes in step S.6), the CPU 15 performs data update processing in units of 8 Kbytes based on the update difference data (step S.6). 7).

Specifically, the CPU 15 performs data update processing through the following five processes.
(1) The CPU 15 extracts the address information of the data recording unit 12 to be updated from the update difference data.
(2) The CPU 15 reads 8 Kbytes of information from the extracted address from the data recording unit 12 and temporarily records it in the SDRAM 13.
(3) The CPU 15 extracts the difference data to be updated, which is recorded in the update difference data, and updates only the difference data among the information of the data recording unit 12 recorded in the SDRAM 13. Data is created and recorded in the SDRAM 13 (4) The CPU 15 erases the information of the data recording unit 12 to be updated by 8 Kbytes based on the address acquired from the server CPU 23.
(5) The CPU 15 reads the updated data (8 Kbytes of data) recorded in the SDRAM 13 and writes it into the erased space of 8 Kbytes of the data recording unit 12.
As described above, when the CPU 15 executes the above-described five processes, the data in the data recording unit 12 is updated on the basis of 8 Kbytes.

  When update difference data in units of 8 Kbytes is not included in the reply information (No in step S.6), or when data update processing is performed using update difference data in units of 8 Kbytes (step S 7), the CPU 15 determines whether or not the reply information includes update difference data in units of 64 Kbytes (step S.8).

  If the reply information includes update differential data in units of 64 Kbytes (Yes in step S.8), the CPU 15 performs data update processing in units of 64 Kbytes based on the update differential data (step S). .9).

Specifically, the CPU 15 performs data update processing through the following five processes.
(1) The CPU 15 extracts the address information of the data recording unit 12 to be updated from the update difference data.
(2) The CPU 15 reads 64 Kbytes of information from the extracted address from the data recording unit 12 and temporarily records it in the SDRAM 13.
(3) The CPU 15 extracts the difference data to be updated, which is recorded in the update difference data, and updates only the difference data among the information of the data recording unit 12 recorded in the SDRAM 13. Data is created and recorded in the SDRAM 13 (4) The CPU 15 erases the information of the data recording unit 12 to be updated by 64 Kbytes based on the address acquired from the server CPU 23.
(5) The CPU 15 reads the updated data (64 Kbytes of data) recorded in the SDRAM 13 and writes it in the erased space of 64 Kbytes of the data recording unit 12.
As described above, when the CPU 15 executes the above-described five processes, the data in the data recording unit 12 is updated with 64 Kbytes as a reference.

  When the reply information does not include update difference data in units of 64 Kbytes (in the case of No in step S.8), or when data update processing is performed using update difference data in units of 64 Kbytes (step S) 9), the CPU 15 determines whether or not all the information to be updated has been updated based on the information about the update acquired from the server CPU 23 (step S.10), and updates all the information. Is not completed (No in step S.10), the above-described processing (step S.4 to step S.9) is repeatedly executed. On the other hand, when all the information has been updated (Yes in Step S.10), the CPU 15 outputs information indicating that the update has been completed to the server CPU 23 via the network line 30 (Step S.10). S.11), the data update process of the data recording unit 12 is terminated.

  The server CPU 23 determines whether or not the information indicating that the update has been completed is received from the CPU 15 (step S.44). If the information is not received (No in step S.44), it is received. The determination process (step S.44) is repeatedly executed.

  Note that information indicating that the update has been completed may not be received from the CPU 15 due to a communication line trouble or the like, and information indicating that the update has been completed may not be received due to a failure in the update. In the process for determining whether or not the timer has been set, a timer is set. If the information indicating that the update is completed is not received after a certain period of time after the information is transmitted by the server 43, the server CPU 23 may forcibly end the update process.

  When the information indicating that the update has been completed is received (Yes in step S.44), the server CPU 23 updates the version information of the data recording unit 12 recorded in the update information recording unit 22 to the latest information. Then, the update process in the data recording unit 12 of the car navigation system 1 is finished (step S.45).

  As described above, in the server 20 according to the present embodiment, whether the update process is necessary in the data recording unit 12 of the car navigation system 1 by acquiring the version information and the hardware information related to the car navigation system 1. Judgment can be made. If it is determined that data update processing is necessary, whether the data recording unit 12 is updated based on the data read from the SD card in units of file data after obtaining the required address and data amount. Based on the update difference data transmitted from the server 20, it is possible to determine whether or not to update the data recording unit 12.

Further, when creating update difference data, the hardware characteristics of the data recording unit 12 to be updated (specifically, the erasable data capacity (block size) of the FLASH memory) are considered, and the formula 1 Based on
BN_8KB × (T_se + (T_bp × 8 × 1024 / WS))
＜ BN_64KB × (T_be + (T_bp × 64 × 1024 / WS)) ・ ・ ・ Equation 1
It is determined whether to create update difference data based on 8 Kbytes or update difference data based on 64 Kbytes. Since T_se, T_be, and T_bp in Equation 1 are all data that depends on the FLASH memory, data update processing is performed by previously recording T_se, T_be, and T_bp related to the FLASH memory of the data recording unit 12 in the server 20. The update difference data can be created in a format (8 Kbytes or 64 Kbytes) that can shorten the update time.

  For this reason, when the update process is performed in the car navigation system 1, the data in the data recording unit 12 can be updated using the update difference data in a format that can most shorten the update process time. Along with the reduction, the update time can be shortened.

  Although the update difference data creation device according to the present invention has been described above, the update difference data creation device according to the present invention is not limited to the above-described embodiment. It will be apparent to those skilled in the art that various changes and modifications can be made within the scope of the claims, and these are naturally within the technical scope of the present invention. Understood.

  For example, in the car navigation system 1 according to the present embodiment, the case where a FLASH memory is used as the data recording unit 12 has been described. However, in recent car navigation systems, there are devices that use an SD card as a recording medium for recording map information and system information.

  The SD card is also a kind of FLASH memory, and has the same characteristics as the FLASH memory in that new data must be written after erasing old data before writing data. For this reason, even in an SD card, the data capacity that can be erased by each erase process can be defined as a block size.

  The SD card is provided with a controller for performing data update (erase / read / write) control in advance, and data is erased, read / written by this controller. However, if the block size for updating the data is different, the data update processing time is different even for the same SD card.

  For this reason, the server CPU 23 obtains an optimum block size for each SD card and creates update difference data in units of the obtained block size, thereby shortening the data update processing time in the SD card. It becomes possible.

First, when the SD card is used as the data recording unit 12, the server CPU 23 determines the block size of the update data so that the value shown in Expression 2 is minimized.
D (BS) / (Wth (BS) + Rth (BS) + Pth (BS)) Equation 2

here,
BS indicates the block size of the update difference data,
D (BS) indicates the amount of rewrite data,
Wth (BS) indicates the write throughput in the SD card,
Rth (BS) indicates the read throughput in the SD card,
Pth (BS) indicates the throughput of patch processing (patch processing throughput) for creating new data for update based on the update difference data.

  Note that the write throughput indicates the number of block sizes of data that can be written per unit time, the value changes according to the number of bytes set as the block size, and the SD card hardware characteristics. It has the property that the value is different depending on it.

  The read throughput indicates the number of block sizes of data that can be read per unit time. The value changes according to the number of bytes set as the block size. It has the property that the value is different depending on it.

  Further, the patch processing throughput refers to the creation of a new version of data per unit time when creating a new version of data based on the old version of data and update difference data recorded on the SD card. The number of possible block sizes is shown, and a value approximated to the memory copy throughput between the SDRAM 13 and the SD card used for patch processing is shown.

  The rewrite data amount D (BS) is obtained from data different between the old version data and the new version data. Further, Wth (BS), Rth (BS), and Pth (BS) can be recorded in the update information recording unit 22 by obtaining them in advance according to the hardware characteristics of the data recording unit 12. is there.

  However, since the values of Wth (BS), Rth (BS), and Pth (BS) change according to the block size (BS) of the update difference data, the server CPU 23 stores the update information recording unit 22 in advance. Based on the data of Wth (BS), Rth (BS), and Pth (BS) for each hardware of the data recording unit 12 to be recorded, a process of calculating the value of Expression 2 is performed.

  The data update processing time in the SD card can be obtained by the sum of (1) writing time, (2) reading time, and (3) patch processing time. Accordingly, the block size (Wth (BS)), the read throughput (Rth (BS)) of the SD card, and the patch processing throughput (Pth (BS)) can be increased together. By obtaining (BS), it is possible to perform efficient write processing, read processing, and patch processing for the rewritten data amount D, and as a result, it is possible to reduce the data update processing time.

  In this way, the server CPU 23 determines the block size (BS) of the update difference data, creates update difference data based on the block size, and the controller of the SD card uses the created update difference data. By performing the update process of the data recorded in the SD card, the data update process time in the SD card can be made shorter than before. Furthermore, since update difference data is created using the smallest block size in Expression 2 and is transmitted to the car navigation system 1 via the network line 30, it is possible to reduce the amount of transmission data.

1. Car navigation system (client)
2 ... Vehicle 5 ... Display unit 6 ... Touch panel unit 10 ... Main unit 11 (for car navigation system) ... Communication unit (for client navigation system) (Client communication means)
12 ... Data recording part (FLASH memory, SD card)
13 ... SDRAM
14 ... SD card read / write unit 15 ... (for car navigation system) CPU (new version data generating means, memory data erasing means, data writing means)
20 ... Server (update difference data creation device, server)
21 ... Communication unit (for server) (server communication means)
22 ... Update information recording section (update information recording means)
23 ... CPU for server (update difference data creation means)
24 ... ROM (for server)
25 ... RAM (for server)
30 ... Network line

Claims (6)

Update information recording means in which old version data recorded in the FLASH memory and newer version data than the old version data are recorded;
In the FLASH memory, the data capacity that can be erased in each erase process is defined as a block size, and the new version data recorded in the update information recording means is compared with the old version data, Update difference data creating means for extracting data of different parts as difference data in the block size unit, and creating update difference data by combining the extracted difference data in the block size unit,
The update difference data creation means includes:
The update difference data when the block size is set to S bytes when S bytes having a small data capacity and L bytes having a large data capacity can be used as the block size of the FLASH memory. The block number BN_S and the block number BN_L of the update difference data when the block size is set to L bytes are calculated, and when the following formula is satisfied, the difference data is calculated in units of S bytes, which is the small data capacity. The update difference data is extracted to create the update difference data, and when the following formula is not satisfied, the update difference data is generated by extracting the difference data in units of L bytes having the large data capacity. Creation device.
BN_S × (T_se + (T_bp × S / WS)) <BN_L × (T_be + (T_bp × L / WS))
However,
BN_S is the number of blocks of the update difference data when the block size is S bytes,
BN_L is the number of blocks of the update difference data when the block size is L bytes,
T_se is the time required to erase S bytes of data in the FLASH memory,
T_be is the time required to erase L bytes of data in the FLASH memory,
T_bp is a write time of data for one word in the FLASH memory,
WS indicates the number of bytes per word in the FLASH memory,
The T_se, T_be, T_bp, and WS data for the FLASH memory are recorded in advance in the update information recording means. Update information recording means in which the old version data recorded on the SD card and the newer version data than the old version data are recorded;
The data capacity that can be erased by each erasure process in the SD card is defined as a block size, and the new version data recorded in the update information recording means is compared with the old version data, Update difference data creating means for extracting data of different parts as difference data in the block size unit, and creating update difference data by combining the extracted difference data in the block size unit,
When a plurality of data capacities can be used as the block size of the SD card, the update information recording means stores the write throughput Wth (BS) of the SD card for each block size BS having a different data capacity. And a reading throughput Rth (BS) of the SD card and a patch processing throughput Pth (BS) of the patch processing for creating the new version data based on the update difference data,
The update difference data creation means includes:
When the data amount of the update difference data is D (BS), a plurality of write throughputs Wth (BS) and a plurality of read throughputs Rth (BS) recorded for each block size BS in the update information recording unit The plurality of patch processing throughputs Pth (BS) are read out to obtain a block size BS that minimizes the value of D (BS) / (Wth (BS) + Rth (BS) + Pth (BS)). The update difference data creating apparatus, wherein the update difference data is created by extracting the difference data in units. FLASH memory in which old version data is recorded,
In the FLASH memory, a data capacity that can be erased by each erasing process is defined as a block size, and the block size is defined as data having different data contents in the old version data and the new version data. New version data generation means for generating new version data based on the update difference data created by extracting and combining in units and the old version data recorded in the FLASH memory;
Memory data erasing means for erasing data of the FLASH memory in units of the block size;
Data writing means for writing the new version data generated by the new version data generating means into the area of the FLASH memory erased by the memory data erasing means;
A client having client communication means capable of outputting version information of the old version to a server via a network line and receiving the update differential data from the server via the network line;
Update information recording means in which all versions of data that can be recorded in the FLASH memory are recorded;
Server communication means capable of receiving the version information output by the client communication means via the network line and outputting the update difference data to the client via the network line;
The version data corresponding to the version information received by the server communication means is acquired from the data recorded in the update information recording means, and the acquired version data and the new information recorded in the update information recording means A server having update difference data creation means for creating update difference data by comparing the version data and extracting the difference data,
The update difference data creation means includes:
The update difference data when the block size is set to S bytes when S bytes having a small data capacity and L bytes having a large data capacity can be used as the block size of the FLASH memory. The block number BN_S and the block number BN_L of the update difference data when the block size is set to L bytes are calculated, and when the following formula is satisfied, the difference data is calculated in units of S bytes, which is the small data capacity. Extract and create the update difference data, when the following formula does not hold, extract the difference data in units of L bytes that are the large data capacity to create the update difference data,
The server communication means outputs the update difference data created by the update difference data creation means to the client,
The client communication means receives the update difference data output by the server,
The new version data generation means generates new version data based on the update difference data received by the client communication means and the old version data recorded in the FLASH memory,
The memory data erasure unit erases the data in the FLASH memory in units of the block size based on the block size constituting the update difference data received by the client communication unit,
The data writing means writes the new version data generated by the new version data generating means in the block size unit into the area of the FLASH memory erased by the memory data erasing means. Data update system.
BN_S × (T_se + (T_bp × S / WS)) <BN_L × (T_be + (T_bp × L / WS))
However,
BN_S is the number of blocks of the update difference data when the block size is S bytes,
BN_L is the number of blocks of the update difference data when the block size is L bytes,
T_se is the time required to erase S bytes of data in the FLASH memory,
T_be is the time required to erase L bytes of data in the FLASH memory,
T_bp is a write time of data for one word in the FLASH memory,
WS indicates the number of bytes per word in the FLASH memory,
The T_se, T_be, T_bp, and WS data for the FLASH memory are recorded in advance in the update information recording means. An SD card on which an old version of data is recorded;
In the SD card, the data capacity that can be erased by each erasing process is defined as a block size, and the block size is defined as data having different data contents in the old version data and the new version data. New version data generation means for generating new version data based on update difference data created by extracting and combining in units, and old version data recorded on the SD card;
Data writing means for writing data of the SD card in units of the block size;
A client having client communication means capable of outputting version information of the old version to a server via a network line and receiving the update differential data from the server via the network line;
Update information recording means in which all versions of data that can be recorded on the SD card are recorded;
Server communication means capable of receiving the version information output by the client communication means via the network line and outputting the update difference data to the client via the network line;
The version data corresponding to the version information received by the server communication means is acquired from the data recorded in the update information recording means, and the acquired version data and the new information recorded in the update information recording means A server having update difference data creation means for creating update difference data by comparing the version data and extracting the difference data,
When a plurality of data capacities can be used as the block size of the SD card, the update information recording means stores the write throughput Wth (BS) of the SD card for each block size BS having a different data capacity. And a reading throughput Rth (BS) of the SD card and a patch processing throughput Pth (BS) of the patch processing for creating the new version data based on the update difference data,
The update difference data creation means includes:
When the data amount of the update difference data is D (BS), a plurality of write throughputs Wth (BS) and a plurality of read throughputs Rth (BS) recorded for each block size BS in the update information recording unit The plurality of patch processing throughputs Pth (BS) are read out to obtain a block size BS that minimizes the value of D (BS) / (Wth (BS) + Rth (BS) + Pth (BS)). Creating the updated difference data by extracting the difference data in units;
The server communication means outputs the update difference data created by the update difference data creation means to the client,
The client communication means receives the update difference data output by the server,
The new version data generation means generates new version data based on the update difference data received by the client communication means and the old version data recorded on the SD card,
The data writing unit writes the new version data generated by the new version data generation unit to the SD card in units of the block size of the update difference data. Update information recording means in which old version data recorded in the FLASH memory and newer version data than the old version data are recorded;
In the FLASH memory, the data capacity that can be erased in each erase process is defined as a block size, and the new version data recorded in the update information recording means is compared with the old version data, Update difference data creating means for extracting data of different portions as the difference data in the block size unit, and creating update difference data by combining the extracted difference data in the block size unit;
An update difference data creation program for causing the update difference data creation means to create the update difference data in an update difference data creation device comprising:
In the update difference data creation means,
The update difference data when the block size is set to S bytes when S bytes having a small data capacity and L bytes having a large data capacity can be used as the block size of the FLASH memory. A block number calculation step of calculating the block number BN_S of the update difference data and the block number BN_L of the update difference data when the block size is L bytes;
When the following formula is satisfied, the difference data is extracted in S byte units having the small data capacity to create the update difference data, and when the following formula is not satisfied, the difference data is generated in L byte units having the large data capacity. An update difference data creation program for executing an update difference data creation step for extracting difference data and creating the update difference data.
BN_S × (T_se + (T_bp × S / WS)) <BN_L × (T_be + (T_bp × L / WS))
However,
BN_S is the number of blocks of the update difference data when the block size is S bytes,
BN_L is the number of blocks of the update difference data when the block size is L bytes,
T_se is the time required to erase S bytes of data in the FLASH memory,
T_be is the time required to erase L bytes of data in the FLASH memory,
T_bp is a write time of data for one word in the FLASH memory,
WS indicates the number of bytes per word in the FLASH memory,
The T_se, T_be, T_bp, and WS data for the FLASH memory are recorded in advance in the update information recording means. The old version data recorded on the SD card and the newer version data than the old version data are recorded, and the data capacity that can be erased by each erase process in the SD card is reduced to the block size. When a plurality of data capacities can be used as the block size of the SD card, the write throughput Wth (BS) of the SD card and the SD card for each block size of different data capacities Update information recording means in which the read throughput Rth (BS) of the patch and the patch processing throughput Pth (BS) of the patch processing for creating the new version data based on the update difference data are recorded,
Compare the new version data and the old version data recorded in the update information recording means, extract the data of different parts of the data contents as the difference data in the block size unit, and the extracted block size unit Update difference data creation means comprising: update difference data creation means for creating update difference data by combining the difference data; and update difference data creation for causing the update difference data creation means to create the update difference data A program,
In the update difference data creation means,
When the data amount of the update difference data is D (BS), a plurality of write throughputs Wth (BS) recorded for each block size in the update information recording unit, a plurality of read throughputs Rth (BS), A minimum block size calculation for reading a plurality of patch processing throughputs Pth (BS) and obtaining a block size BS that minimizes the value of D (BS) / (Wth (BS) + Rth (BS) + Pth (BS)). Steps,
An update difference data creation program for executing an update difference data creation step of creating the update difference data by extracting the difference data in units of the block size BS calculated in the minimum block size calculation step.

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