JP5664264B2 - Data processing apparatus and data processing method - Google Patents

Description

  The present invention relates to a data processing apparatus and a data processing method.

  Conventionally, it is important to improve transfer efficiency when transferring data. For this reason, various techniques have been proposed. As one of the proposed technologies, a technology has been proposed in which when transferring a large amount of data to a device that performs data transfer in units of sectors, a plurality of sectors are regarded as one sector and transferred. By using such a transfer technique, it is possible to improve transfer efficiency.

  However, the above-described conventional technology considers only the case where the data transfer size is larger than one sector, and does not consider the case where the size of data to be transferred is smaller than one sector. Therefore, when the data size of the data to be transferred is smaller than the data size of one sector, there is a problem that transfer performance is lowered because unnecessary data needs to be packed and adjusted.

  The present invention has been made in view of the above, and proposes a data processing apparatus and a data processing method that improve transfer performance according to the data size of data to be transferred.

In order to solve the above-described problems and achieve the object, the data processing apparatus according to the present invention controls data transmission in units of data size equal to or larger than the sector length of the storage medium when transmitting / receiving data to / from the storage medium. Transmitting means, a recognition means for recognizing the data size of a plurality of files to be transmitted to the storage medium, and a file having a data size smaller than the sector length among the plurality of files, Based on the size of redundant data when transmitting the small file in units of data size, a determination unit that determines whether to transmit in the data size unit that is equal to or greater than the sector length, and a determination that the determination unit does not transmit If the transmission means transmits a file smaller than the sector length, the transmission means is based on the data size of the file. Comprising an adjusting means for adjusting a data size unit stage is transmitted, said data said determining means further total data size of the redundant data of the sector plurality of smaller than length file, said transmitting means transmits When it is larger than the data size of the change instruction to change the size unit, it is determined not to transmit in the data size unit equal to or greater than the sector length, and the adjustment unit is determined not to transmit by the determination unit, The change command adjusts a data size unit that the transmission means transmits at a time .

  According to the present invention, it is possible to suppress a decrease in transfer performance.

FIG. 1 is a block diagram illustrating a configuration of the ASIC according to the embodiment. FIG. 2 is a diagram showing an example in which a 256-byte file is transmitted six times to an SD card having one sector of 512 bytes using a conventional method. FIG. 3 is a diagram showing an example in which the ASIC according to this embodiment transmits a 256-byte file to the SD card six times. FIG. 4 is a diagram showing a control flow when the ASIC transmits data to the SD card. FIG. 5 is a diagram showing a processing flow for the determination unit to determine whether or not to adjust the transfer data size when transmitting a file, and to specify the next timing to adjust the transfer data size. FIG. 6 is a diagram showing an example of the number of redundant bytes when one file is transmitted when a transfer data size change command is issued and when it is not issued. FIG. 7 is a diagram showing an example of the number of redundant bytes when two files are transmitted when a transfer data size change command is issued and when it is not issued. FIG. 8 is a diagram showing an example of the number of redundant bytes when four files are transmitted when a transfer data size change command is issued and when it is not issued. FIG. 9 is a diagram showing an example of the number of redundant bytes when two files are transmitted when a transfer data size change command is issued and when it is not issued. FIG. 10 is a diagram showing the total number of redundant bytes when the transfer data size is not changed even once. FIG. 11 is a diagram showing the total number of redundant bytes when the transfer data size is changed only once. FIG. 12 is a diagram showing the total number of redundant bytes when the transfer data size is changed twice.

  Exemplary embodiments of a data processing device and a data processing method according to the present invention will be explained below in detail with reference to the accompanying drawings. In this embodiment, an example in which the data processing apparatus of the present invention is applied to an ASIC will be described.

(Embodiment)
FIG. 1 is a block diagram illustrating a configuration of the ASIC according to the embodiment. The ASIC can be mounted on various information processing apparatuses that can read and write data from / to a storage medium. Therefore, in this embodiment, an example in which the ASIC is mounted on a general information processing apparatus such as a PC (Personal Computer) will be described.

  As shown in FIG. 1, the ASIC 102 includes a memory 103, a transfer data buffer 104, a DMAC 105, an SD host 106, a data transfer control unit 107, a determination unit 108, and a recognition unit 109. The ASIC 102 is connected to the CPU 101. Then, the CPU 101 performs setting and control of the ASIC 102. As described above, the ASIC 102 performs various processes in accordance with instructions from the CPU 101. Further, the ASIC 102 can read / write data from / to the SD card 112 when the SD card 112 is connected.

  The SD card 112 is a storage medium that is a target of data transmission / reception in units of sectors. In this embodiment, an example in which the SD card 112 is used as a storage medium will be described. However, data may be transmitted / received to / from a storage medium other than the SD card, a device or the like as a transmission / reception target. Next, data transmission to the SD card 112 will be described.

  FIG. 2 is a diagram showing an example in which a 256-byte file is transmitted six times to an SD card having one sector of 512 bytes using a conventional method. As shown in FIG. 2, in the conventional transfer method, when a file having a data size smaller than the sector length is transmitted, the file is transmitted after filling with redundant data. In the example shown in FIG. 2, since the sector length is 512 bytes and the file size of the transferred file is 256 bytes, 256 bytes of redundant data are packed and transmitted to the SD card. That is, in the conventional method, when a 256-byte file is transmitted six times, a total of 256 bytes × 6 redundant data is transmitted. As described above, in the conventional method, since data transfer which is not originally required is performed, the transfer time and the use area on the storage medium side become redundant, and the performance is lowered.

  FIG. 3 is a diagram illustrating an example in which the ASIC 102 according to the present embodiment transmits a 256-byte file to the SD card 112 six times. As shown in FIG. 3, the sector length of one sector is 512 bytes, and the unit of the data size transmitted / received between the ASIC 102 and the SD card 112 is also 512 bytes in the initial setting (hereinafter referred to as the SD card 112). A data size unit transmitted and received at a time is referred to as a transfer data size). However, since a 256-byte file is transmitted six times, the ASIC 102 according to this embodiment transmits a 256-byte file six times after issuing a command to change the transfer data size from 512 bytes to 256 bytes in advance. To do.

  As described above, in this embodiment, since the file is transmitted after the transfer data size is changed to be equal to the file size, there is no redundant part in the transmitted data, and the transfer performance can be improved. it can. Returning to FIG. 1, a specific configuration of the ASIC 102 will be described.

  The memory 103 stores data to be transferred to the SD card 112 and data transferred from the SD card 112.

  A DMAC (Direct Memory Access Controller) 105 controls memory access without the intervention of the CPU 101.

  The recognition unit 109 recognizes data sizes of a plurality of files stored in the memory 103 for transmission to the SD card 112.

  The transfer data buffer 104 stores the transfer data read from the memory 103. The transfer data buffer 104 rearranges transfer data according to a predetermined transfer order when reading data from the memory 103. The transfer data buffer 104 according to the present embodiment rearranges the transmission order so that the plurality of files to be transmitted to the SD card 112 are transmitted in the order of the data size recognized by the recognition unit 109. If the transfer files are stored in the memory 103 in the order suitable for the present embodiment, the transfer data buffer 104 is not necessary.

  The determination unit 108 includes a pre-change redundant byte number storage unit 121, a post-change redundant byte number storage unit 122, a redundant byte number comparison unit 124, and a sector length change byte number storage unit 123. On the other hand, it is determined whether or not to change the transfer data size.

  When the recognition result by the recognition unit 109 includes a file whose data size is smaller than the sector length of the SD card 112, the determination unit 108 according to the present embodiment performs the processing in units of data size equal to or greater than the sector length. Based on the size of the redundant data when transmitting the file, it is determined whether or not to transmit with a transfer data size equal to or larger than the sector length. That is, the determination unit 108 transmits the size of the total redundant data when the SD host 106 transmits the plurality of files stored for transmission to the memory 103 with the transfer data size equal to or larger than the sector length. If the data size is larger than the data size of the transfer data size change command, it is determined that transmission is not performed with a transfer data size equal to or greater than the sector length, in other words, the change command is issued and transmitted with a smaller transfer data size. On the other hand, when the size of the total redundant data is smaller than the data size of the transfer data size change command transmitted by the SD host 106, the determination unit 108 continues to transmit with a transfer data size equal to or greater than the sector length. judge.

  When the recognition unit 109 recognizes that the file to be transmitted to the SD card 112 includes a plurality of files having a data size smaller than the sector length of the SD card 112, the determination unit 108 according to the present embodiment transfers After the files are rearranged by the data buffer 104 in the descending order of the data size, the determination is made in order from the file having the largest data size.

  Then, the determination unit 108 determines in order from a file with a larger data size, stops the SD host 106 from transmitting with a transfer data size equal to or larger than the sector length, and starts transmission with a transfer data size smaller than the sector length. Determine timing. In order to determine the timing, the determination unit 108 includes a pre-change redundant byte number storage unit 121, a post-change redundant byte number storage unit 122, a redundant byte number comparison unit 124, a sector length change byte number storage unit 123, Is used.

  The pre-change redundant byte number storage unit 121 includes a data size of each file recognized by the recognition unit 109, an order in which the files are rearranged by the transfer data buffer 104 in descending order of data size, and the SD host 106 performs the current transfer Based on the data size, the sum of the number of bytes of redundant data when the transfer data size is not changed in the nth file is temporarily stored.

  The post-change redundant byte count storage unit 122 adjusts the data size of each file recognized by the recognition unit 109, the order in which the files are rearranged in the descending order of the data size by the transfer data buffer 104, and the adjustment unit 111 Based on the transfer data size of the SD host 106, the sum of the number of bytes of redundant data when the transfer data size is adjusted in the nth file is temporarily stored.

  Therefore, the determination unit 108 according to the present embodiment transmits the redundant data size from the transfer data size (initially the same data size as the sector length of the SD card 112) transmitted by the SD host 106. Calculate by subtracting the file data size.

  The redundant byte number comparison unit 124 compares the sum of the number of bytes stored in the pre-change redundant byte number storage unit 121 with the sum of the number of bytes stored in the post-change redundant byte number storage unit 122. In other words, the redundant byte count comparing unit 124 determines that the sum of redundant data by continuously transmitting a plurality of files without adjusting the transfer data size is redundant by continuously transmitting a plurality of files by adjusting the transfer data size. It is determined whether or not the sum of the data sum and the data size of the change command exceeds the sum.

  In the present embodiment, the determination unit 108 determines the timing determined by the redundant byte number comparison unit 124 as the change timing for changing the data size transmitted by the SD host 106. A specific timing determination method will be described later.

  Then, the determination unit 108 may change the transfer data size transmitted by the SD host 106 a plurality of times by repeatedly performing the above-described determination. After the determination unit 108 changes the transfer data size to be transmitted and before determining the timing for adjusting the next transfer data size, for each of all files transmitted by the SD host 106, When the comparison based on the sum of redundant data after the change is completed, it is considered that there is no timing to change the transfer data size thereafter, and the timing calculation is terminated.

  The data transfer control unit 107 includes an adjustment unit 111 and controls data transfer between the SD card 112 and the ASIC 102.

  When the adjustment unit 111 of the data transfer control unit 107 according to the present embodiment changes the transfer data size according to the determination result of the determination unit 108, the adjustment of the transfer data size is suspended or the transfer data size change command is set. Set the transfer data size after change.

  If the determination unit 108 determines that the determination unit 108 does not transmit with a transfer data size equal to or larger than the sector length of the SD card 112, in other words, issues a change command and transmits with a smaller transfer data size, When the SD host 106 transmits a file having a transfer data size smaller than the length, a transfer data size change command transmitted by the SD host 106 is issued based on the transfer data size of the file. Thereby, the transfer data size transmitted by the SD host 106 is adjusted. On the other hand, the adjustment unit 111 does not adjust the transfer data size when the SD host 106 transmits when the determination unit 108 determines that the total size of the redundant data is smaller than the data size of the change command.

  The SD host 106 serves as an interface for connecting the SD card 112 and the ASIC 102, and transmits / receives data to / from the SD card 112 and issues commands. Data transmission and command issuance to the SD card 112 are performed in accordance with requests from the DMAC 105 and the CPU 101. When the SD host 106 transmits a file, the PIO transfer (Programmed Input / Output) is performed with a transfer data size that is the same size as one sector length of the SD card 112, and the same as the sum of a plurality of sector lengths. Transmission of the size of the transfer data size or multiple transmissions by the DMAC 105 is performed. As described above, the SD host 106 according to the present embodiment controls data transmission with the transfer data size based on the sector length of the SD card 112 when transmitting and receiving data to and from the SD card 112.

  As described above, the adjustment unit 111 of the data transfer control unit 107 performs setting instead of the CPU 101, thereby enabling data transfer to the SD card 112 while changing the transfer data size without software intervention. .

  FIG. 4 is a diagram showing a control flow when the ASIC 102 transmits data to the SD card 112. In this control flow, when the SD host 106 transmits, 512 bytes, which is the sector length size of the SD card 112, is set as the initial value of the transfer data size. When the initial value of the sector length is different, the following description is also changed according to the sector length.

  First, the recognizing unit 109 checks the transfer data size of all transfer files stored in the memory 103 (step S401).

  Then, after the transfer data buffer 104 reads each file from the memory 103, the files are rearranged and stored so as to be transmitted from the largest data according to the transfer data size recognized by the recognition unit 109. In this way, the transfer order of each file is set (step S402).

  Then, the determination unit 108 determines whether there is a file having a data size (512 bytes) of one sector length or more (step S403). If it is determined that there is no file having a data size of one sector length or more (step S403: No), the process proceeds to step S406.

  If the determination unit 108 determines that a file having a data size of one sector length or more exists (step S403: Yes), the determination unit 108 further determines that all files transmitted to the SD card 112 have one sector length. It is determined whether or not the data size is the above (step S404). When it is determined that the data size is one sector length or more (step S404: Yes), the SD host 106 transmits the file read from the transfer data buffer 104 to the SD card 112 via the DMAC 105 (step S404). S411).

  Thereafter, the SD host 106 determines whether or not transmission has been completed for all files (step S412). If the transmission is not completed (step S412: No), the file is continuously transmitted (step S411). If the transmission of all the files is completed (step S412: Yes), the process is terminated.

  On the other hand, when the determination unit 108 determines that all the files transmitted to the SD card 112 do not have a data size of one sector length or more, in other words, include files having a data size smaller than one sector length ( First, the SD host 106 acquires all files having a data size larger than one sector length from the transfer data buffer 104 and transmits them to the SD card 112 (step S405).

  Then, the determination unit 108 determines whether or not to adjust the transfer data size when transmitting the file, and specifies the timing for adjusting the transfer data size next (step S406).

  Thereafter, the determination unit 108 determines whether there is an adjustment of the transfer data size (step S407). When the determination unit 108 determines that the transfer data size has been adjusted (step S407: Yes), the adjustment unit 111 adjusts the transfer data size for transmitting the file (step S408). As the transfer data size to be set, the number of bytes of the file having the largest data size among the untransferred files at this stage is set. The reason for setting the number of bytes of the file with the largest data size is that if a value smaller than the file size is set as the transfer data size that the SD host 106 transmits at one time, a plurality of times are used to transfer one file. This is because transfer is required and transfer performance is deteriorated.

  Then, the SD host 106 transmits the file read from the transfer data buffer 104 in the adjusted transfer data size unit (step S409).

  Next, the determination unit 108 determines whether or not the next adjustment timing has come (step S410). If it is determined that it is not the adjustment timing (step S410: No), the SD host 106 continuously transmits the file (step S409). When it is determined that the adjustment timing has come (step S410: Yes), the determination unit 108 and the data transfer control unit 107 determine whether to adjust the transfer data size when transmitting the file, and then transfer data size. The timing for adjusting is specified (step S406). Thereafter, the determination unit 108 determines whether there is an adjustment of the transfer data size (step S407).

  If it is determined that the transfer data size is no longer adjusted (step S407: No), the process proceeds to step S411, the SD host 106 transmits the file with the currently set transfer data size, and all files are transmitted. When the process is completed (step S412), all the processes are completed.

  FIG. 5 illustrates determination of whether or not to adjust the transfer data size when the file is transmitted by the determination unit 108 shown in step S <b> 406 of FIG. 4, and the next timing for adjusting the transfer data size. It is the figure which showed the processing flow.

  First, when the determination unit 108 transmits a file with the current transfer data size, it calculates the number of redundant bytes for all the files to be transmitted (step S501). Next, the determination unit 108 determines whether or not the calculated number of redundant bytes is larger than the number of bytes of the transfer data size change command (step S502). If it is determined that the number of bytes of the transfer data size change command is larger than the calculated number of redundant bytes (step S502: No), the process is terminated assuming that the transfer data size will not be changed.

  On the other hand, when the determination unit 108 determines that the calculated number of redundant bytes is larger than the number of bytes of the transfer data size change command (step S502: Yes), it sets that the transfer data size change command is issued ( Step S503). The setting to issue the change command means that the flag for changing the transfer data size in step S407 in FIG. 4 is set to ON. If this flag is ON, the transfer data size is adjusted in step S408.

  Then, the determination unit 108 sets an initial value “0” for the variable n (step S504). The variable n is a number for identifying a file to be transmitted after changing the transfer data size. For example, n = 0 represents a file to be transferred first after adjusting the transfer data size.

  Next, the determination unit 108 calculates the number of redundant bytes when the transfer data size is not changed in the nth file (step S505). Then, the determination unit 108 stores the sum of the number of redundant bytes when the transfer data size is not changed in the nth file in the pre-change redundant byte number storage unit 121.

  Next, the determination unit 108 calculates the number of redundant bytes when the transfer data size is changed for the nth file (step S506). Then, the determination unit 108 stores the sum of the redundant byte numbers when the transfer data size is changed in the nth file in the changed redundant byte number storage unit 122.

  Thereafter, the redundant byte number comparison unit 124 determines that the sum of the redundant byte numbers when the transfer data size is not changed in the nth file is the sum of the redundant byte numbers when the transfer data size is changed and the byte number of the change command. It is determined whether or not the sum is larger than (step S507).

  Then, the redundant byte number comparison unit 124 determines that the sum of the redundant byte numbers when the transfer data size is not changed is equal to or less than the sum of the redundant byte number when the transfer data size is changed and the byte number of the change command. If it is determined (step S507: No), '1' is added to the variable n (step S508), and it is determined whether or not all files have been compared (step S509). If the redundant byte number comparison unit 124 determines that the comparison has not been completed for all files (step S509: No), the process returns to step S505 and proceeds again. If the redundant byte number comparison unit 124 determines that the comparison has been completed for all the files (step S509: Yes), the process is terminated because the performance is better if the transfer data size is not changed.

  On the other hand, when the redundant byte number comparison unit 124 does not change the transfer data size, the sum of the redundant byte numbers is larger than the sum of the redundant byte number when the transfer data size is changed and the byte number of the change command. When the determination is made (step S507: Yes), the file whose transfer data size has been changed is set as the “0” th, and the time when the n + 1th file is transmitted is set as the transfer data size adjustment timing, and the process ends ( Step S510).

  By the processing procedure described above, it is possible to set a command for changing the transfer data size and a timing for changing the transfer data size next.

  Next, an example of transmitting a file to the SD card 112 will be described. The files to be transmitted are: file A: 150 bytes, file B: 260 bytes, file C: 380 bytes, file D: 700 bytes, file E: 1024 bytes, file F: 128 bytes, file G: 32 bytes, File H: 70 bytes. The initial value of the transfer data size is 512 bytes which is the same as the sector length of the SD card. The number of bytes of the transfer data size change command is also 512 bytes.

  In step S401 in FIG. 4, the recognition unit 109 recognizes the data size of each file. In step S401, the transfer order is changed in the transfer data buffer 104. As a result, the first: file E / 1024 bytes, the second: file D / 700 bytes, the third: file C / 380 bytes, the fourth: file B / 260 bytes, the fifth: file A / 150 bytes, the sixth : File F / 128 bytes, 7th: File H / 70 bytes, 8th: File G / 32 bytes.

  Thereafter, since there is a file of 512 bytes or more in the determination in step S403, the process proceeds to step S404. Then, in the determination in step S404, since a file of 512 bytes or more and a file smaller than 512 bytes are mixed, the process proceeds to step S405. In step S <b> 405, the SD host 106 transmits the file E and the file D to the SD card 112. Thereafter, in step S406, the transfer data size change data size adjustment determination is performed.

  In step S501 in FIG. 5, since the currently set transfer data size is 512 bytes, the redundant bytes of the untransferred file are calculated as follows.

  That is, the third file C has 512 bytes-380 bytes = 132 bytes, the fourth file B has 512 bytes-260 bytes = 252 bytes, the fifth file A has 512 bytes-150 bytes = 362 bytes, the sixth file The file F is 512 bytes-128 bytes = 384 bytes, the seventh file H is 512 bytes-70 bytes = 442 bytes, and the eighth file G is 512 bytes-32 bytes = 480 bytes.

  Accordingly, the number of redundant bytes in the untransferred portion is 2052 bytes, which is larger than 512 bytes, which is the initial value of the transfer data size, and the process proceeds to step S503. Then, issue of a transfer data size change command is set.

  Then, after the initial value “0” is set to the variable n, the determination unit 108 calculates the number of redundant bytes when the transfer data size is not changed and when it is changed in Step S505 and Step S506.

  The transfer data size when not changing is 512 bytes, and the transfer data size when changing is 380 bytes, which is the maximum value of the untransferred file (third file C). For this reason, the number of redundant bytes is calculated and compared.

  FIG. 6 is a diagram showing an example of the number of redundant bytes when one file (file C) is transmitted when the transfer data size change command is issued and when it is not issued. In the example illustrated in FIG. 6, it is determined in step S507 in FIG. 5 that the number of redundant bytes when the transfer data size is not changed is smaller, and the process proceeds to step S508. Then, after adding 1 to the variable n, since all untransferred files are not compared, the process proceeds to step S505, and the comparison is performed again.

  FIG. 7 is a diagram showing an example of the number of redundant bytes when two files (file C and file B) are transmitted when a transfer data size change command is issued and when it is not issued. . In the example illustrated in FIG. 7, it is determined in step S507 in FIG. 5 that the number of redundant bytes when the transfer data size is not changed is smaller, and the process proceeds to step S508. Then, after adding 1 to the variable n, since all untransferred files are not compared, the process proceeds to step S505, and the comparison is performed again. Thereafter, these processes are repeated until the number of redundant bytes when the change command is issued becomes smaller than when the change command is not issued.

  FIG. 8 shows an example of the number of redundant bytes when four files (file C, file B, file A, and file F) are transmitted when the transfer data size change command is issued and not issued. FIG. In the example shown in FIG. 8, it is determined in step S507 of FIG. 5 that the number of redundant bytes when the transfer data size is not changed is larger, and the process proceeds to step S510. When the file H is transmitted, the change command adjustment timing is determined again. Thereafter, the flow for determining the transfer data size change ends, and the process proceeds to step S407 in FIG.

  Since it is set to issue the change command in step S503, the determination unit 108 determines that the transfer data size is adjusted (step S407: Yes). In step S408, the adjustment unit 111 transfers the transfer data. Adjust the size. The transfer data size is set to a maximum size of 380 bytes in the untransferred file.

  Thereafter, in the loop part of steps S409 and S410, after the SD host 106 transmits up to the file F, the adjustment timing set in step S510 of FIG. 5 is reached, so the process proceeds from step S410 to step S406.

  This time as well, the transfer data size change is determined as before. When the number of redundant bytes is calculated for each untransferred file based on the current transfer data size of 380 bytes, the seventh file H / 380 bytes-70 bytes = 310 bytes, the eighth file G / 380 bytes-32 bytes = 348 bytes. Since the total number of redundant bytes of these untransferred files is 658 bytes and is larger than 512 bytes of the transfer data size change command, a setting is made to issue the change command. Similarly to the previous time, when the number of redundant bytes is compared between when the transfer data size is changed and when it is not changed, the table shown in FIG. 9 is obtained. FIG. 9 is a diagram showing an example of the number of redundant bytes when two files (file H and file G) are transmitted when a transfer data size change command is issued and when it is not issued. . After the transfer data size adjustment determination process in FIG. 5 is completed, the adjustment unit 111 changes the transfer data size to 70 bytes, which is the data size of the file H. Then, after transferring the file H, the SD host 106 again determines whether to change the transfer data size.

  Since the untransferred file is as follows, when the number of redundant bytes is calculated based on the current transfer data size of 70 bytes, the eighth file G becomes 70 bytes−32 bytes = 38 bytes. For this reason, since the total number of redundant bytes is smaller than 512 bytes which is the number of bytes of the change command, the setting that the change command is issued is not performed, and the transfer data size change shown in FIG. The determination flow ends.

  In this case, the determination unit 108 determines that there is no adjustment of the transfer data size (step S407: No), proceeds to step S411, and repeats until the SD host 106 completes all the processes for transmitting the file. Then, when the transmission of all files is completed, all the processes are finished.

  Hereinafter, the number of redundant bytes based on the number of times of changing the transfer data size will be described. However, description of file transfer of 512 bytes or more is omitted. FIG. 10 is a diagram showing the total number of redundant bytes when the transfer data size is not changed even once. In the example shown in FIG. 10, the number of redundant bytes is 2052 bytes.

  FIG. 11 is a diagram showing the total number of redundant bytes when the transfer data size is changed only once. In the example shown in FIG. 11, the number of redundant bytes is 1772 bytes. FIG. 12 is a diagram showing the total number of redundant bytes when the transfer data size is changed twice. In the example shown in FIG. 12, the number of redundant bytes is 1664 bytes.

  As shown in FIGS. 10 to 12, it can be confirmed that the number of redundant bytes decreases according to the number of times the change command is performed.

  The ASIC 102 according to the present embodiment described above can prevent a decrease in transfer performance caused by an unmatch between the transfer data size and the sector length of the SD card 112 when transferring a plurality of files without intervention by software.

  Furthermore, it is possible to prevent a decrease in transfer performance caused by the transfer data size when a plurality of files are transmitted from the ASIC 102 to the SD card 112. Since the transfer data size can be set to an optimum value on the hardware side in accordance with the file size of the transmitted file, unnecessary data transfer can be prevented from occurring.

(Modification)
In the above-described embodiment, the example in which the above-described ASIC 102 is mounted on the information processing apparatus has been described. However, the above-described ASIC 102 is not limited to being mounted on the information processing apparatus. Therefore, as a modification, the ASIC 102 may be mounted on the image forming apparatus. When the ASIC 102 is mounted on the image forming apparatus, the ASIC 102 performs the same processing as the above-described embodiment when transferring a plurality of image data smaller than the data size of the sector length of the SD card 112 to the SD card 112. And Thereby, it is possible to improve transfer efficiency when image data having a small data size is transferred to the SD card 112. Further, the output destination of the image data is not limited to the SD card, and may be performed on another storage medium such as a compact flash (registered trademark) card or a magneto-optical disk.

  In the modification, the image forming apparatus can be applied to a multifunction machine having at least two functions of a copy function, a printer function, a scanner function, and a facsimile function. The present invention can be applied to any image forming apparatus.

101 CPU
102 ASIC
103 Memory 104 Transfer Data Buffer 105 DMAC
106 SD host 107 Data transfer control unit 108 Judgment unit 109 Recognition unit 111 Adjustment unit 112 SD card 121 Redundant byte count storage unit before change 122 Redundant byte count storage unit after change 123 Sector length changed byte count storage unit 124 Redundant byte number comparison unit

Japanese Patent Laid-Open No. 2003-077719

Claims (9)

A transmission unit that controls transmission of data in units of data size equal to or greater than the sector length of the storage medium when transmitting and receiving data to and from the storage medium;
Recognition means for recognizing the data sizes of a plurality of files to be transmitted to the storage medium;
When a file having a data size smaller than the sector length is included among the plurality of files, the file size is equal to or larger than the sector length based on the size of redundant data when the small file is transmitted in the data size unit. Determining means for determining whether to transmit in units of the data size;
An adjustment unit that adjusts a data size unit transmitted by the transmission unit based on a data size of the file when the transmission unit transmits a file smaller than the sector length when the determination unit determines not to transmit the file. When,
Equipped with a,
The determination unit is further configured such that the total data size of redundant data of a plurality of files smaller than the sector length is larger than the data size of the change instruction for changing the data size unit transmitted by the transmission unit. It is determined not to transmit in the data size unit greater than the sector length,
The adjustment means adjusts the data size unit that the transmission means transmits at a time with the change command when it is determined that the determination means does not transmit;
A data processing apparatus. Order setting means for setting the transmission order so that the plurality of files to be transmitted to the storage medium are transmitted in descending order of the data size recognized by the recognition means;
The transmission means further transmits a file transmitted after the small file in the transmission order in a data size unit equal to or less than the data size adjusted by the adjustment means,
The data processing apparatus according to claim 1 . If it is determined by the determination means that transmission is not performed in units of the data size equal to or greater than the sector length,
The determining means further sum of redundant data by continuing to send multiple files without adjusting the data size unit, the redundant data due to adjust the data size unit continues to send multiple files Determine whether the sum exceeds the sum of the data size of the change instruction to change the data size unit ,
The adjusting unit adjusts the data size unit transmitted by the transmitting unit at a timing determined by the determining unit to exceed,
The data processing apparatus according to claim 2 . The determination means, when a plurality of files having a data size smaller than the sector length is included among the plurality of files, for the plurality of small files, determining in order from the largest file size,
The data processing apparatus according to claim 2 or 3, characterized in. If the comparison of the redundant data is completed for each of all the files transmitted by the transmission unit before the determination unit determines the next timing to adjust the data size unit, without calculating the timing, The data processing apparatus according to claim 4 , wherein the processing proceeds. The adjusting means does not adjust the data size unit when the transmitting means transmits when the determining means determines that the total size of the redundant data is smaller than the data size of the change instruction;
The data processing apparatus according to any one of claims 1 to 5, characterized in. The determining means, the data processing device according to the size of the redundant data, that obtained by subtracting the data size of the small files from the sector length, any one of claims 1 to 6, wherein. When the transmission means transmits a file, it performs transmission in a data size unit of one sector length by PIO transfer (Programmed Input / Output), transmission in a data size unit of a plurality of sector lengths, or multiple transfer by DMAC. The data processing apparatus according to any one of claims 1 to 7 . A data processing method executed by a data processing device,
A transmission step for controlling transmission of data in units of data size greater than or equal to the sector length of the storage medium when the transmission means transmits and receives data to and from the storage medium;
A recognition step for recognizing data sizes of a plurality of files transmitted to the storage medium by a recognition unit;
When the determination unit includes a file having a data size smaller than the sector length among the plurality of files, based on the size of redundant data when transmitting the small file in units of the data size, A first determination step for determining whether to transmit in units of the data size equal to or greater than the sector length;
When it is determined that the adjustment unit does not transmit in the determination step, when the transmission step transmits a file smaller than the sector length, the data size unit transmitted by the transmission step is determined based on the data size of the file. A first adjustment step to adjust;
Only including,
In the case where the determination means further has a larger data size of the redundant data of the plurality of files smaller than the sector length compared to the data size of the change instruction for changing the data size unit transmitted by the transmission means, A second determination step of determining not to transmit in units of the data size equal to or greater than the sector length;
A second adjustment step of adjusting a data size unit transmitted by the transmission unit at a time with the change command when the adjustment unit determines that the transmission is not performed in the first determination step;
A data processing method comprising:

Images