JP2019020989A - Recording device - Google Patents

Abstract

To provide a recording apparatus capable of issuing a write command for each memory data and writing data on a recording medium without impairing the transfer rate of the recording medium and also provide a control method thereof.SOLUTION: A recording apparatus (100) for recording data on a recording medium (115), which includes acquisition means for acquiring a unit size from the recording medium (S401), notification means for notifying the recording medium of a total write size that is an integral multiple of the unit size of the recording medium acquired by the acquisition means (S403), and issuing means for issuing a plurality of write commands to the recording medium after notification of the total write size by the notification means, in which the issuing means issues the plurality of write commands so that the sum of write sizes of the plurality of write commands becomes the total write size notified by total write size notification means (S404 to S408).SELECTED DRAWING: Figure 4

Description

  The present invention relates to a recording apparatus and a control method thereof.

  In recent years, NAND flash memory (registered trademark) has become mainstream as a recording medium for digital cameras and digital video cameras. A memory device that is a NAND flash memory has a minimum writing size of one sector (512 bytes), and the transfer rate is fast when the write size to the memory device is large, and the transfer rate is slow when the write size is small. There is.

  The NVMe (Non-Volatile Memory Express) standard is disclosed as a standard of a logical device interface for connecting a memory device to a host through PCI Express, and is widely used in SSDs as memory devices. As a framework for guaranteeing the writing speed, Directives specification is added in Version 1.3 of the NVMe standard.

  In the Directives specification, a framework is proposed in which a host obtains a write size (SGS (Stream Granularity Size), etc.) from a memory device, and writes to the memory device with the size, thereby producing optimum write performance.

  Here, the operation sequence of the Directives specification will be described with reference to FIG.

  In step S2011, the host 2000 issues a Direct Receive command and acquires a return parameter from the memory device 2001. Return parameters include Stream Write Size (SWS), Stream Granularity Size (SGS), and the like, which store the write size expected by the memory device. SWS is the minimum write size, and SGS is a size for writing a plurality of SWSs as one unit.

  In step S2012, the host 2000 issues an Enable Direct command to enable the Direct function of the memory device 2001.

  In step S2013, the host 2000 issues a write command to the memory device 2001 to perform writing. At this time, the host 2000 writes with a write size that is N times the SGS acquired in step S2011. In addition, a 01h flag indicating the stream data is added to the Direct Specific (DSPEC) field of the write command.

  In step S2014, the memory device 2001 identifies the stream data from the DSPEC field described above, and performs control so that the write size specified in step S2013 can be written to the internal NAND with the optimum write performance.

  In general, in order to obtain a transfer rate in a memory device using a NAND flash memory, it is necessary to increase the write size to several megabytes, and the SGS acquired from the memory device in the Directives specification is similarly large.

NVM Express revision 1.3 specification April 26, 2017

  However, in order to write to a memory device with a large size, it is necessary to allocate a continuous memory area on the host side, so it is necessary to secure a huge buffer. In general, in order to use the memory efficiently, the host uses an area fragmented in a certain unit, and therefore cannot write to the memory device in SGS units.

  On the other hand, in the NVMe standard, SGL (Scatter Gather List) is provided as a specification in which a memory device reads and collects fragmented host data, but it is optional and is not installed in a general memory device. It is also possible to copy the fragmented memory data to another continuous memory area and re-arrange it before writing to the memory device on the host side, but the overhead of the memory bus bandwidth on the host side, copy processing Time overhead and the like occur and become a burden on the system.

  The present invention has been made in view of the above points, and a recording apparatus capable of issuing a write command for each memory data and writing the data on the recording medium without impairing the transfer rate of the recording medium, and its control The purpose is to provide a method.

In order to solve the above problems, the recording apparatus of the present invention provides:
A recording apparatus for recording data on a recording medium having a flash memory, an acquisition unit for acquiring a unit size from the recording medium, and a total write having a size that is an integral multiple of the unit size of the recording medium acquired by the acquisition unit A notifying unit for notifying the recording medium of the size, and an issuing unit for issuing a plurality of write commands to the recording medium after notifying the total write size by the notifying unit, wherein a total of the write sizes of the plurality of write commands is And issuing means for issuing a plurality of write commands so as to achieve the total write size notified by the notification means.

  According to the present invention, the host issues a write command for each fragmented memory data, but can write to the recording medium without impairing the transfer rate of the recording medium.

Block diagram showing the configuration of the recording apparatus FIG. 3 is a diagram illustrating a memory arrangement image of the recording apparatus according to the first embodiment. 6 is a flowchart showing a recording operation of the recording apparatus according to the first embodiment. FIG. 3 is a diagram illustrating a control sequence of the recording apparatus according to the first embodiment. The figure which shows the field information of the write command of the recording device concerning 2nd Embodiment The figure which shows the control sequence of the recording device which concerns on 3rd Embodiment. The figure which shows the field information of the write command of the recording device which concerns on 3rd Embodiment. The figure which shows the operation | movement sequence of the write to the memory device in the conventional recording device

Example 1
FIG. 1 is a block diagram illustrating a configuration of a recording apparatus 100 according to the first embodiment.

  In the following description, parts specific to the present invention will be mainly described. Note that general detailed operations related to NVMe will be understood by referring to the respective standards.

<Recording device>
The system control unit 101 includes a microcomputer, and controls the operation of the recording apparatus 100 by executing a program recorded in the nonvolatile memory 102. The recording apparatus 100 may be controlled by a single piece of hardware, or the entire recording apparatus may be controlled by a plurality of pieces of hardware sharing the processing.

  The nonvolatile memory 102 stores a program for operating the system control unit 101. The RAM 103 stores various data necessary for the processing of the system control unit 101. The SDRAM 107 holds various information such as input image data or management information.

  The imaging processing unit 104 includes an optical lens, an imaging sensor such as a CMOS, a shutter, a diaphragm, and the like. The imaging processing unit 104 images a subject, performs processing such as defect correction, and holds image data in the SDRAM 107 via the memory bus 120. The development processing unit 105 reads the image data after the imaging process recorded in the SDRAM 107 via the memory bus 120. Then, development processing such as resizing processing such as pixel interpolation, filter processing, and reduction, color conversion processing, and processing for conversion to a format of Y, Cb, Cr format, which is an optimal format for saving in compressed image data, is performed. The image processed by the development processing unit 105 is held in the SDRAM 107 via the memory bus 120. The encoding unit 106 reads the image processed by the development processing unit 105 from the SDRAM 107 via the memory bus 120, and performs JPEG or H.264 encoding. The amount of information is compressed by performing encoding processing such as H.264. The encoded image data is recorded on the recording medium 115 via the SDRAM 107 and the host controller 114. The display control unit 108 controls to read the image data processed by the development processing unit 105 from the SDRAM 107 via the memory bus 120, scale up or down according to the display device, and output the image data to the display unit 109. In addition, the display unit 109 is a touch panel, and the user can instruct the recording apparatus 100 to operate by operating the touch panel of the display unit 109. In addition, the user can instruct the recording apparatus 100 to operate by a user operation on an operation unit (not shown).

  The host controller 114 communicates with the recording medium 115 via a connector (not shown) and transmits various commands and data to the recording medium 115 in order to record and read data on the recording medium 115. .

  The information acquisition unit 110 uses the NVMe standard Direct Receive command from the recording medium 115 to acquire the Stream Direct information from the recording medium 115. Specifically, the host controller 114 issues a Direct Receive command to the recording medium 115. Then, the unit size is obtained by the Stream Granularity Size (SGS) included in the response parameter transmitted from the recording medium 115 as the response.

  The total write size notifying unit 111 operates the host controller 114 to notify the recording medium 115 of the total write size of a plurality of write commands to be issued and the total number of write commands to be issued to the recording medium 115 using a Direct command. .

  The write command issuing unit 112 controls the host controller 114 to issue a write command to the recording medium 115. Further, when issuing a plurality of write commands after notification of the total write size, the write command is issued by adding the number of times information indicating how many write commands each write command is. This is to notify the recording medium 115 of how many times the current write command is for the total write size notified by the total write size notification unit 111.

  The write size control unit 113 controls the write size when the image data stored in the SDRAM 107 is written to the recording medium 115.

  The recording medium 115 is a recording medium that has a NAND flash memory therein and is detachable from the recording apparatus 100.

<Image of Memory Arrangement of Recording Apparatus 100>
FIG. 2 is a diagram for explaining an image of memory arrangement of the recording apparatus 100 according to the present embodiment.
In moving image recording, the SDRAM 107 is divided into a Video Data 1 area 201, a Video Data 2 area 202, a Video Data 3 area 203, an Audio Data 1 area 204, and an Audio Data 2 area 205. And it uses as a ring buffer in each area | region. Each region is a data output destination buffer of the encoding unit 106.

  FIG. 2 shows an example of this embodiment, and does not limit the memory arrangement and usage. In FIG. 2, a total of five areas are set, with three Video Data areas and two Audio Data areas. Depending on the system configuration of the recording apparatus 100, the number of fragmented areas is set to five or more. May be.

<Flow chart during recording>
Next, processing when recording moving image data on the recording medium 115 in the recording apparatus 100 will be described. FIG. 3 is a diagram for explaining the recording process in this embodiment.

  In a recording standby state, when the user operates the touch panel of the display unit 109 or an operation unit (not shown) to instruct to start recording moving image data, the following recording process is started.

  In step S301, the system control unit 101 controls the imaging processing unit 104 and the development processing unit 105 to perform image data shooting processing and development processing, and further controls the encoding unit 106 to generate moving image data and audio data. Perform the encoding process. The encoded data is stored in the Video Data1 area 201, the Video Data2 area 202, the Video Data3 area 203, the Audio Data1 area 204, and the Audio Data2 area 205, which are buffer areas of the SDRAM 107, respectively.

  In step S302, the system control unit 101 calculates the total amount of moving image data and audio data unrecorded on the recording medium 115 accumulated in the buffer area of the SDRAM 107, and the total data amount reaches the threshold value T. It is determined whether or not. When the threshold value T is reached, the process proceeds to step S303. If the threshold value T has not been reached, the process proceeds to step S306.

  In step S303, the system control unit 101 controls the write size control unit 113 to determine the write size of each write command when issuing a write command in each of the areas 201 to 205 in the subsequent step S305. The write size control unit 113 determines the write size of each write command so that the sum of the write sizes of the plurality of write commands issued in step S305 is N times the unit size (SGS, etc.) of the acquired Stream Directive information. To do. The unit size is acquired from the recording medium 115 by the information acquisition unit 110 in step S401 in FIG.

  In step S304, the system control unit 101 controls the total write size notifying unit 111 to write to the recording medium 115 by issuing a plurality of write commands in step S305. Notify the number of issues. Here, the total write size notified to the recording medium 115 is the sum of the write sizes of the plurality of write commands calculated in step S303. The total number of write commands issued corresponds to the number of write commands whose write size has been determined in step S303.

  In step S305, a write command for the total number of writes notified in step S304 is issued, and the write size of each write command is set to the write size determined in step S303. Accordingly, the total write size of the plurality of write commands issued in step S305 is the total write size notified in step S304. In addition, the system control unit 101 controls the write command issuing unit 112 to add the current write command count information and issue each write command. That is, the number information indicating the number of write commands is added to the write command field, which will be described later, with respect to the total number of write commands issued by the total write size notification unit 111, and a write command is issued. In the write command, the address of the physical memory SRAM 107 in which data to be written is stored is described in a predetermined field. Therefore, the recording medium 115 can acquire data of a specified size from the address of the specified physical memory and write it to the internal NAND. The system control unit 101 updates the file system for the recording medium 115 in a timely manner. The process from step S303 to step S305 is summarized as step S310.

  In step S306, the system control unit 101 determines whether or not recording is stopped. If there is no instruction to stop recording, the system control unit 101 returns to step S301.

  When a recording stop instruction is given by a user operating the touch panel of the display unit 109 or an operation unit (not shown), the system control unit 101 detects it in step S307. Then, encoding of moving image and audio data by the encoding unit 106 is stopped, and accumulation of encoded data in the buffer area of the SDRAM 107 is stopped.

  In step S308, the system control unit 101 controls the host controller 114 to remain in the Video Data1 area 201, the Video Data2 area 202, the Video Data3 area 203, the Audio Data1 area 204, and the Audio Data2 area 205, which are buffer areas of the SDRAM 107. The unrecorded moving image and audio data are written in the recording medium 115. Then, after updating the file system, the recording process is terminated.

  Note that in the writing in step S308, the total size of data written by the write command does not match the unit size, so the writing speed may be reduced. However, since the writing operation is performed after the instruction to stop recording, there is no problem even if the writing performance is lowered.

  Next, processing when issuing a plurality of write commands using the Direct command will be described in detail. FIG. 4 is a diagram for explaining the control sequence of the Direct command in this embodiment.

  In step S 401, the system control unit 101 controls the information acquisition unit 110 to issue a Direct Receive command from the host controller 114 and acquire a return parameter from the recording medium 115. Return parameters include Stream Write Size (SWS) and Stream Granularity Size (SGS). SWS and SGS indicate units of a write size at which the recording medium 115 can write to the internal NAND with the optimum write performance. The SWS is the minimum size, and the SGS is a write size that guarantees high-speed write performance by handling a plurality of SWSs as one unit.

  Next, in step S <b> 402, the system control unit 101 controls the host controller 114 to issue an Enable Direct command to the recording medium 115 and validate the Direct function of the recording medium 115.

  Steps S401 and S402 need only be performed once at the time of startup, and may be performed, for example, when the recording apparatus is turned on. However, in step S402, when the Direct function is used again after the Direct function is disabled, it is necessary to issue the Enable Direct command again to enable the Direct function.

  In step S403, the system control unit 101 controls the total write size notification unit 111 to notify the recording medium 115 of the total write size to be written and the total number of write commands issued. In this embodiment, the command used here adds a new parameter (for example, 02h) indicating the total size transmission to the Direct Operations Value of the Direct Send command.

  The recording medium 115 receives the notification of the total write size and the total number of issuances, so that the data size to be written and the number of write commands can be known in advance.

  In step S404, the system control unit 101 controls the write command issuing unit 112 to issue a write command to the recording medium 115. Since the number information is not defined in the NVMe standard, the Direct Type Value in the Direct Specific field is extended and used. Direct Specific (DSPEC) The setting of the Stream flag (01h) of the Direct Type Value of the Field and the number of times information indicating the number of write commands are added. That is, in step S404, the write command issuance count is set to 1. Further, according to the NVMe standard, the write size of each write command is set to n times the sector size (for example, 512 bytes). Therefore, the write data is designated by an integer multiple of the sector size (512 bytes) from the Video Data1 area 201 of the SDRAM 107, and a write command is issued to the recording medium 115.

  In step S405, the system control unit 101 controls the write command issuing unit 112 to issue a write command to the recording medium 115. In the write command to be issued, the setting of the Stream flag (01h) of the Direct Type Value of the Direct Specific Field and the number of write command issuance are specified as 2. The data to be written is designated by an integer multiple of the sector size from the Video Data2 area 202 of the SDRAM 107, and a write command is issued to the recording medium 115.

  In step S406, the system control unit 101 controls the write command issuing unit 112 to issue the write command to the recording medium 115. In the write command to be issued, the setting of the Stream flag (01h) of the Direct Type Value in the Direct Specific Field and the number of write command is specified as 3. The write data is designated from the Video Data 3 area 203 of the SDRAM 107 by an integral multiple of the sector size and a write command is issued to the recording medium 115.

  In step S407, the system control unit 101 controls the write command issuing unit 112 to issue a write command to the recording medium 115. In the write command to be issued, the setting of the Stream flag (01h) of the Direct Type Value in the Direct Specific Field and the number of write command issuance are specified as 4. The write data is designated from the Audio Data 1 area 204 of the SDRAM 107 by an integral multiple of the sector size and a write command is issued to the recording medium 115.

  In step S408, the system control unit 101 controls the write command issuing unit 112 to issue a write command to the recording medium 115. In the write command to be issued, the setting of the Stream flag (01h) of the Direct Type Value of the Direct Specific Field and the number of write command issuance are specified as 5. The write data is designated from the Audio Data2 area 205 of the SDRAM 107 by an integral multiple of the sector size and a write command is issued to the recording medium 115.

  The system control unit 101 specifies that the logical address of the write destination memory device specified by the write command from step S404 to step S408 is continuously increased linearly.

  Steps S403 to S408 correspond to step S310 shown in FIG.

  Therefore, the system control unit 101 monitors the total amount of data accumulated in each fragmented buffer in step S302, and repeats step S310 each time the total size reaches the threshold value T.

  As described above, according to the first embodiment, when the recording apparatus 100 issues a write command for each area fragmented in the SDRAM 107, it notifies the recording medium 115 of the total write size and the total number of write commands issued in advance. . Then, control is performed so that the total write size is written with N times the optimum unit size acquired from the recording medium 115. With the above control, the recording medium 115 can be prepared for writing before receiving the write command, so that it is possible to write to the internal NAND with optimum write performance.

  In the first embodiment, the recording mode of the recording apparatus 100 is set as moving image recording as an example. However, the recording mode is not limited and can be performed in still image recording or other recording modes.

  In step S403, the notification of the total write size and the total number of write commands issued to the recording medium 115 is made by adding a parameter indicating the total size transmission to the Direct Operations Value of the Direct Send command. However, the types of commands and parameters are not limited. Also, other notification methods can be implemented.

  Further, in steps S404 to S408, the notification of the write command count information to the recording medium 115 is to extend the Direct Type Value of the Direct Specific Field of the write command. However, the types of commands and parameters are not limited. Also, other notification methods can be implemented.

  In this embodiment, the total write size is calculated based on the total size of data stored in the five memory areas from the area 201 to the area 205 shown in FIG. 2, but the number of fragmented memory areas is five. It is not limited to.

(Example 2)
Next, a second embodiment of the present invention will be described. In the first embodiment, the write size specified by each write command is set to an integral multiple of the sector size. In the second embodiment, a configuration in which the write size of each write command is changed to a byte size will be described.

  The configuration example of the recording apparatus according to the second embodiment is the same as the configuration and operation described with reference to FIG.

  The memory arrangement image of the recording apparatus 100 (FIG. 2), the moving image recording sequence (FIG. 3), and the control sequence of the Direct command (FIG. 4) are also the same as those in the first embodiment, and thus description thereof is omitted.

  In the second embodiment, the operation method of the write command from step S404 to step S405 in the control sequence of the Direct command in FIG. 4 is different.

  In the NVMe standard, the write size specified in the write command is defined as n times the sector size, so the byte size cannot be specified. Therefore, in order to specify the byte size, the SGL (Scatter Gather List) format defined in the existing NVMe standard is used.

  FIG. 5 is a diagram for explaining the write command extension in this embodiment.

  500 is a write command format defined in the NVMe standard. A field 501 designates the write size, which is designated by an integral multiple of the sector size.

  PSDT 503 is a field indicating PRP or SGL for Data Transfer, and 00h specifies that the PRP mode is operated, and 01h and 02h specify that the SGL mode is operated. In this embodiment, a value indicating the byte access mode is added to the PSDT 503. (For example, currently reserved 11b)

  Reference numeral 504 denotes an SGL Segment format. The NVMe standard defines that the SGL Segment 504 is arranged at the memory address of the SDRAM 107 specified by the SGL Segment Pointer 502. Reference numeral 505 denotes a field for designating a write size, which can be set by an arbitrary integer multiple.

  The above description is applied to the control sequence of the Direct command in FIG.

  In step S403, the system control unit 101 controls the total write size notification unit 111 to notify the total size to be written and the total number of write commands issued. In this embodiment, a command to be used is newly added (for example, 02h) a parameter indicating total size transmission to the Direct Operations Value of the Direct Send command.

  When the recording medium 115 receives the notification of the total write size, the data size to be written and the number of write commands can be known in advance.

  In step S404, the system control unit 101 controls the write command issuing unit 112 to issue a write command. In the write command to be issued, the setting of the Stream flag (01h) of the Direct Type Value in the Direct Specific Field and the number of times information indicating the number of write commands are added. That is, in step S404, 1 is designated as the number of write command issuances. In addition, the data to be written is designated from the Video Data1 area 201 of the SDRAM 107 to Number of Logical Blocks 501 by rounding it to an integer multiple of the sector size. At the same time, the byte size is designated in the Length 505 of the SGL Segment 504 that is the memory address destination of the SDRAM 107 in which the actual write size is designated by the SGL Segment Pointer 502. Also, a value indicating the byte access mode is set in PSDT 503 and a write command is issued.

  In step S405, the system control unit 101 controls the write command issuing unit 112 to specify 2 for the setting of the Stream flag (01h) of the Direct Type Value of the Direct Specific Field and the number of write command issuance. Also, the data to be written is set in Number of Logical Blocks 501 by rounding the data from the Video Data2 area 202 of the SDRAM 107 by an integral multiple of the sector size. At the same time, the byte size is specified in the Length 505 of the SGL Segment 504 that is the memory address specified by the SGL Segment Pointer 502 with the actual write size. Also, a value indicating the byte access mode is set in PSDT 503 and a write command is issued.

  In step S406, the system control unit 101 controls the write command issuing unit 112 to issue a write command. In the write command to be issued, the setting of the Stream flag (01h) of the Direct Type Value in the Direct Specific Field and the number of write command is set to 3. The data to be written is set in Number of Logical Blocks 501 by rounding the data from the Video Data3 area 203 of the SDRAM 107 by an integral multiple of the sector size. At the same time, as the actual write size, the byte size is designated in the Length 505 of the SGL Segment 504 that is the memory address designated by the SGL Segment Pointer 502. Also, a value indicating the byte access mode is set in PSDT 503 and a write command is issued.

  In step S407, the system control unit 101 controls the write command issuing unit 112 to issue a write command. In the write command to be issued, the setting of the Stream flag (01h) of the Direct Type Value of the Direct Specific Field and the number of write command is set to 4. In addition, the data to be written is set in the Number of Logical Blocks 501 by rounding the data from the Audio Data1 area 204 of the SDRAM 107 by an integral multiple of the sector size. At the same time, as the actual write size, the byte size is designated in the Length 505 of the SGL Segment 504 that is the memory address designated by the SGL Segment Pointer 502. Also, a value indicating the byte access mode is set in PSDT 503 and a write command is issued.

  In step S408, the system control unit 101 controls the write command issuing unit 112 to issue a write command. In the write command to be issued, the setting of the Stream flag (01h) of the Direct Type Value of the Direct Specific Field and the number of write command is set to 5. The data to be written is set in Number of Logical Blocks 501 by rounding the data from the Audio Data2 area 205 of the SDRAM 107 by an integral multiple of the sector size. At the same time, as the actual write size, the byte size is designated in the Length 505 of the SGL Segment 504 that is the memory address designated by the SGL Segment Pointer 502. Also, a value indicating the byte access mode is set in PSDT 503 and a write command is issued.

  Steps S403 to S408 correspond to step S310 shown in FIG.

  Therefore, the system control unit 101 monitors the total amount of data accumulated in each fragmented buffer in step S302, and repeats step S310 each time the total size reaches the threshold value T.

  As described above, according to the second embodiment, the recording apparatus 100 issues a write command for each area fragmented in the SDRAM 107. The total write size and the number of write commands issued are notified to the recording medium 115 in advance, and the total write size is controlled to be written at N times the optimum unit size acquired from the recording medium 115. In addition, the write size of each write command can be specified in byte size using SGL Segment.

  With the control described above, the recording apparatus 100 can manage each fragmented memory area with a byte size buffer, so that the system operation is facilitated by the restriction of an integral multiple of the sector size. In addition, since the recording medium 115 can be prepared for writing before receiving the write command, it is possible to write to the internal NAND with optimum write performance.

  In the second embodiment, the recording mode of the recording apparatus 100 is set as moving image recording as an example. However, the recording mode is not limited and can be performed in still image recording or other recording modes.

  In step S403, the notification of the total write size and the total number of write commands issued to the recording medium 115 is made by adding a parameter indicating the total size transmission to the Direct Operations Value of the Direct Send command. However, the types of commands and parameters are not limited. Also, other notification methods can be implemented.

  Further, in steps S404 to S408, the notification of the write command count information to the recording medium 115 is to extend the Direct Type Value of the Direct Specific Field of the write command. However, the types of commands and parameters are not limited. Also, other notification methods can be implemented.

  In this embodiment, the total write size is calculated based on the total size of data stored in the five memory areas from the area 201 to the area 205 shown in FIG. 2, but the number of fragmented memory areas is five. It is not limited to.

  In this embodiment, the byte address is notified by SGL Segment. However, the notification method is not limited, and other notification means can be used.

(Example 3)
Next, a third embodiment of the present invention will be described. In the first and second embodiments, the total write size of a plurality of write commands is controlled to be N times the unit size. In the third embodiment, a configuration is described in which control is performed so that the total write size of descriptors connected in one write command is N times the unit size.

  The configuration example of the recording apparatus according to the second embodiment is basically the same as the configuration and operation described with reference to FIG. 1 according to the first embodiment, but the present embodiment further includes a descriptor generation unit.

  Further, the memory arrangement image (FIG. 2) and the moving image recording sequence (FIG. 3) of the recording apparatus 100 are also the same as those in the first embodiment, and the description thereof is omitted.

  FIG. 6 is a diagram for explaining a control sequence using a descriptor in this embodiment.

  Note that the moving image recording operation that is the premise of this sequence is the same as that in the flowchart of FIG. 3, and step S610 applies to the operation of S310 described in FIG.

  Since step S601 is the same as step S401 and step S602 is the same as step S402, description thereof is omitted here.

  Before describing descriptor generation in step S603, a write command and descriptor configuration will be described. FIG. 7 is a diagram for explaining the configuration of the write command and the descriptor.

  In the present embodiment, the descriptor generation unit generates the following descriptor using the SGL (Scatter Gather List) format defined in the NVMe standard. Since details of the SGL format are described in the NVMe standard, only the points relating to the present invention will be described here.

  700 is a write command format defined by the NVMe standard. A field 701 designates a write size, which is designated by an integral multiple of the sector size.

  A PSDT 703 is a field indicating PRP or SGL for Data Transfer, and 00h specifies operation in the PRP mode, and 01h and 02h specify operation in the SGL mode. In this embodiment, the SGL mode is designated.

  710 is a format of SGL Segment. The NVMe standard defines that the SGL Segment 710 is arranged at the memory address of the SDRAM 107 specified by the SGL Segment Pointer 702. Reference numeral 711 designates the address and write size of the fragmented memory area of the SDRAM 107, for example, the Video Data1 area 201. Reference numeral 712 designates a memory address at which the next descriptor is arranged. Reference numeral 713 designates the address and write size of the next fragmented memory area, for example, the Video Data2 area 202. Reference numeral 704 designates a memory address where the next descriptor is arranged. The configuration of 711 to 714 is generated for the fragmented memory area, and the address and size of the last memory area are designated as 710 + n. According to the NVMe standard, the write size specified by the descriptor can be specified by the byte size. The total number of descriptors used in the write command is specified by extending the Reserved area of 703.

  In step S603, the system control unit 101 controls the descriptor generation unit to generate write descriptors for the number of memory areas fragmented on the SDRAM 107. Note that the write size of each descriptor is determined so that the total write size specified by the descriptor is N times the unit size (such as SGS) of the Stream Directive information acquired in step S601.

  In step S604, the system control unit 101 controls the write command issuance unit 112 to set the Stream Type flag (01h) of the Direct Specific Value of the Direct Specific Field. The write size of the write command is N times the unit size determined in step S603, and the value of the total write size specified by the descriptor is specified and the write command is issued.

  After the write command is issued, in step S604 (a), the recording medium 115 reads the data in the Video Data1 area 201 by the specified size from the descriptor specified by the SGL Segment Pointer of the write command.

  In step S604 (b), the recording medium 115 reads the data in the Video Data2 area 202 for the specified size from the next descriptor.

  In step S604 (c), the recording medium 115 reads the data in the Video Data3 area 203 for the specified size from the next descriptor.

  In step S604 (d), the recording medium 115 reads data in the Audio Data1 area 204 for the specified size from the next descriptor.

  In step S604 (e), the recording medium 115 reads the data in the Audio Data2 area 205 by the designated size from the next descriptor.

  As described above, according to the third embodiment, the recording apparatus 100 generates descriptors for the areas fragmented in the SDRAM 107 and notifies the recording medium 115 of the total number of descriptors. Further, control is performed so that the total write size is written with N times the optimum unit size acquired from the recording medium 115.

  With the above control, the recording apparatus 100 can write each fragmented memory area with a single write command, thereby reducing the command issuing overhead. Further, since the recording medium 115 can be prepared for writing when a write command is received, it is possible to write to the internal NAND with optimum write performance.

  In the third embodiment, the recording mode of the recording apparatus 100 is set as moving image recording as an example. However, the recording mode is not limited and can be performed in still image recording or other recording modes.

  Further, in step S603, the notification of the total number of descriptors to the recording medium 115 is to extend the reserved area of the write command, but the present invention is not limited to this, and other notification methods can be used.

  In this embodiment, the total write size is calculated based on the total size of data stored in the five memory areas from the area 201 to the area 205 shown in FIG. 2, but the number of fragmented memory areas is five. It is not limited to.

Claims (12)

A recording device for recording data on a recording medium having a flash memory,
Obtaining means for obtaining a unit size from the recording medium;
Notification means for notifying the recording medium of a total write size that is an integral multiple of the unit size of the recording medium acquired by the acquiring means;
Issuing means for issuing a plurality of write commands to the recording medium after notifying the total write size by the notifying means, wherein the sum of the write sizes of the plurality of write commands is notified by the notifying means. And a issuing unit that issues the plurality of write commands so as to achieve the total write size.   The recording apparatus according to claim 1, wherein the issuing unit issues the plurality of write commands such that write destination addresses of the plurality of write commands are continuous.   The recording apparatus according to claim 1, wherein the issuing unit issues the plurality of write commands so that a write size of each write command is an integral multiple of a predetermined size.   The recording apparatus according to claim 3, wherein the predetermined size is a sector size of the recording medium. The notification means notifies the total number of writes together with the total light size,
The recording apparatus according to claim 1, wherein the issuing unit issues a plurality of write commands corresponding to the total number of writes notified by the notification unit.   6. The recording apparatus according to claim 5, wherein the issuing unit issues a write command by adding, to each write command, information related to the number of write commands issued with respect to the total number of writes notified by the notification unit.   The recording apparatus according to claim 6, wherein the issuing unit adds information regarding the number of times the write command is issued by expanding a field of a Direct Specific (DSPEC) defined in the NVMe standard.   The recording apparatus according to claim 1, wherein the notification unit extends the Operation Value of a Direct Send command defined in the NVMe standard and notifies the total write size.   The recording apparatus according to claim 1, wherein the acquisition unit acquires a unit size from the recording medium using an NVMe standard Direct Receive command.   The recording apparatus according to claim 1, wherein the issuing unit specifies a write size of each write command of the plurality of write commands by using a byte size using a descriptor defined in the NVMe standard. A recording device for recording data on a recording medium having a flash memory,
Obtaining means for obtaining a unit size from the recording medium;
Generating means for generating a descriptor in which an instruction for recording data of a specified write size on the recording medium is described, and generating means for generating a plurality of descriptors;
Issuing means for issuing a write command to the recording medium, and issuing means for issuing a write command using a total size of write sizes specified by the plurality of descriptors as a write size of the write command,
A recording apparatus, wherein a total size of write sizes specified by the plurality of descriptors is an integral multiple of a unit size acquired by the acquisition unit.   12. The recording apparatus according to claim 11, wherein the generation unit generates the descriptor in an SGL Segment format defined by the NVMe standard.

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