JP2006172625A - Data control apparatus, and residual quantity detecting method of buffer data - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To detect accurately residual quantity of data to be written in order to calculate residual quantity of data accumulated in a buffer. <P>SOLUTION: The apparatus is a data control apparatus having a first buffer accumulating successively transmitted data with an area unit, a second buffer accumulating successively data generated in accordance with recording processing contents with the area unit, and taking out data from the first or the second buffer with the area unit and output it, further, the apparatus has a first detecting means detecting the number of areas of data accumulated in the first buffer, a second detecting means detecting the number of areas based on the number of areas detected by the first detecting means out of the number of areas of data accumulated in the second buffer, and a third detecting means detecting residual quantity of data from the number of areas detected by the first detecting means and the number of areas detected by the second detecting means. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a data control device for detecting the remaining amount of buffer data and a method for detecting the remaining amount of buffer data.

  2. Description of the Related Art Conventionally, a data recording processing apparatus that writes data transmitted from a computer that is a data generation source on a recording medium such as a DVD is known.

  In order to adjust the difference between the data rate transmitted from the computer device and the rate at which data is recorded on the recording medium, such a data recording processing device temporarily stores the data transmitted from the computer device. A storage buffer for accumulation is provided.

  By the way, when the speed of data transmitted from the computer apparatus becomes slower than the speed at which the data recording processing apparatus writes to the recording medium, the buffer underrun where the remaining amount of data accumulated in the storage buffer is insufficient. The phenomenon that occurs.

When such a phenomenon occurs, the buffer management means of the data recording processing device interrupts the writing to the recording medium and stands by, cancels the interruption when a predetermined amount or more of data is accumulated in the storage buffer, and again Although a so-called burn-proof function for performing writing is operated (see, for example, Patent Document 1), the performance of the firmware of the data recording apparatus has been lowered by the operation of the proof-proof function.
JP 2003-77131 A

  In the data recording processing apparatus as described above, not only the data to be recorded on the recording medium is transmitted from the computer apparatus, but also the data generated in the data recording processing apparatus such as subcode data and pause data is stored separately. After being stored in the buffer, it is written to the recording medium.

  However, since the data recording processing device calculates the remaining amount of data accumulated in the buffer based on only the remaining buffer amount of data transmitted from the computer device, it is generated by the data processing recording processing device. Data was not taken into account.

  Therefore, the remaining amount of data to be written on the recording medium cannot be accurately detected, and a problem of erroneous detection of buffer underrun has occurred.

  This erroneous detection causes an unnecessary perm proof function to operate, resulting in a decrease in the performance of the firmware of the data recording processing apparatus.

  SUMMARY OF THE INVENTION An object of the present invention is to provide a data control apparatus and a buffer data remaining amount detection method that are free from erroneous detection of buffer underrun by detecting an accurate remaining amount of data.

  Therefore, according to the first aspect of the present invention, the first buffer for sequentially storing data transmitted from the computer apparatus in units of areas, and the data generated in accordance with the recording processing contents to the recording medium are sequentially stored in units of areas. A second buffer for accumulating, taking out data from the first or second buffer in units of areas based on a plurality of data processing commands generated according to the contents of recording processing, and outputting the data to a recording medium A first control means for detecting the number of areas of data stored in the first buffer, and a first detection of the number of areas of data stored in the second buffer. From the second detection means for detecting the number of areas based on the number of areas detected by the means, the number of areas detected by the first detection means and the number of areas detected by the second detection means, the data It was to have a third detecting means for detecting the remaining amount.

  According to a second aspect of the present invention, in the data control device according to the first aspect, the detection of the number of areas in the second detection means is continuously performed together with the data of the number of areas detected by the first detection means. Thus, the number of data areas that can be output to the recording medium is detected.

  According to a third aspect of the present invention, in the data control device according to the first aspect, the detection of the number of areas in the second detection means is a first detection among the data processing commands for the second buffer. Detecting a data processing command necessary for outputting all the data of the number of areas detected by the means to the recording means, and detecting the number of areas of data to be processed by the detected second data processing command. It was.

  According to a fourth aspect of the present invention, in the data control apparatus according to the third aspect, the data processing command is processed with an identifier field for identifying whether the data processing command is for the first buffer or the second buffer. And the second detection means detects the number of areas from the information of the identifier field and the repetition number field.

  Further, in the present invention according to claim 5, the first buffer for sequentially storing data transmitted from the computer apparatus in units of areas, and the data generated in accordance with the recording processing contents on the recording medium are sequentially stored in units of areas. A second buffer for accumulating, taking out data from the first or second buffer in units of areas based on a plurality of data processing commands generated according to the contents of recording processing, and outputting the data to a recording medium A method for detecting a remaining amount of buffer data in a device, wherein a first step of detecting the number of areas of data stored in a first buffer and a number of areas of data stored in a second buffer From the second step of detecting the number of areas based on the number of areas detected in the first step, the number of areas detected in the first step, and the number of areas detected in the second step, It was to have a third step of detecting the remaining amount of data.

  According to the first aspect of the present invention, the first buffer for sequentially storing data transmitted from the computer apparatus in units of areas, and the data generated in accordance with the contents of recording processing on the recording medium are sequentially stored in units of areas. A data control unit that has a second buffer, extracts data in units of areas from the first or second buffer based on a plurality of data processing commands generated according to the recording processing content, and outputs the data to a recording medium The first detection means for detecting the number of areas of data stored in the first buffer and the first detection means among the number of areas of data stored in the second buffer. The remaining amount of data from the second detection means for detecting the number of areas based on the detected number of areas, the number of areas detected by the first detection means and the number of areas detected by the second detection means Since the number of areas of unprocessed data in the buffer of the data control apparatus that can be actually executed can be accurately detected, performance deterioration due to erroneous detection of buffer underrun can be achieved. Can be prevented.

  In the present invention according to claim 2, the number of areas detected by the second detecting means is the number of areas of data that can be continuously output to the recording medium together with the number of areas detected by the first detecting means. Since it is detected, the remaining amount of data can be easily detected.

  According to the third aspect of the present invention, the detection of the number of areas in the second detection means records all the data of the number of areas detected by the first detection means among the data processing commands for the second buffer. Since the data processing command necessary for output to the means is detected and the number of data areas to be processed by the detected second data processing command is detected, the remaining data amount can be easily determined based on the data processing command. Can be detected.

  In the present invention according to claim 4, the data processing command includes an identifier field for identifying whether the data processing command is for the first buffer or the second buffer, and a repetition number field indicating the number of areas of data to be processed. Since the second detection means detects the number of areas from the information in the identifier field and the repetition number field, since the repetition number field is provided in the data processing command, the same control command is executed a plurality of times. Even in this case, it is not necessary to write the data processing command to the memory for the data processing command a plurality of times, so that the performance of the writing process can be improved and the memory capacity for the data processing command can be reduced. .

  In addition, since the identifier field is provided in the data processing command, it becomes easy to identify whether the data processing command processes the data in the first buffer or the data in the second buffer.

  Further, in the present invention according to claim 5, the first buffer for sequentially storing data transmitted from the computer apparatus in units of areas, and the data generated in accordance with the recording processing contents on the recording medium are sequentially stored in units of areas. A second buffer for accumulating, taking out data from the first or second buffer in units of areas based on a plurality of data processing commands generated according to the contents of recording processing, and outputting the data to a recording medium A method for detecting a remaining amount of buffer data in a device, wherein a first step of detecting the number of areas of data stored in a first buffer and a number of areas of data stored in a second buffer From the second step of detecting the number of areas based on the number of areas detected in the first step, the number of areas detected in the first step, and the number of areas detected in the second step, And the third step of detecting the remaining amount of data, it is possible to accurately detect the number of unprocessed data areas of the buffer that can be actually executed. Can be prevented.

  Hereinafter, a data control apparatus according to an embodiment of the present invention will be specifically described with reference to the drawings.

  FIG. 1 is a diagram showing a data control apparatus according to an embodiment of the present invention.

  This data control device is connected between an external computer device (hereinafter referred to as “host”) and a recording medium such as an optical disk such as a CD or a DVD. After temporarily generating data generated according to the recording content in the buffer, the data is extracted from the buffer according to the recording content on the recording medium and transmitted to the recording medium via the encoder.

  In FIG. 1, the data control device 1 includes a data storage device 10, a command storage device 20, a data access device 30, a command access device 40, a control device 50, and a CPU 60.

  The data storage device 10 is in accordance with a main ring buffer (hereinafter referred to as “WMRB”) that is a first buffer for sequentially storing data transmitted from the host in area units, and according to the content of recording processing on the recording medium. A sub-ring buffer (hereinafter referred to as “WSRB”) and a linear buffer (hereinafter referred to as “WLB”), which are second buffers for sequentially storing data generated by a CPU 60 to be described later in area units. have. Here, the second buffer such as WSRB or WLB is referred to as a WMRB outside buffer.

  Note that data generated according to the content of recording processing on a recording medium includes subcode data and pause data.

  Further, the number of second buffers is not limited to two and may be one.

  Further, although SDRAM is used as the data storage device 10, it is not limited to this.

  Each area can store a certain amount of data.

  The command storage device 20 includes a data processing command used for processing data stored in each buffer in each buffer of the data storage device 10 and command control for calculating the remaining data using the data processing command. Device 21.

  Note that the command storage device 20 can use storage elements such as flip-flops, SRAMs, and SDRAMs in accordance with system requirements, costs, and processing complexity.

  Further, as shown in FIG. 2, the data processing command includes a WMRB identification field, a repetition number field, a pointer control field, and a data control field.

  In the WMRB identifier field, a value of “1” is set when the data processing command is for WMRB, and a value of “0” is set when the command is for a buffer other than WMRB.

  In the repeat number field, the number of times the process for data on the same buffer is repeated by the data processing command is set. The provision of this field eliminates the need for the CPU 60 to write commands having the same data processing contents to the command storage device 20, thereby reducing the CPU load and the memory area of the command storage device 20.

  If 0 is specified in the number of repetitions field of the data processing command, this means the end of writing.

  The pointer control field is a command for controlling a read pointer (hereinafter referred to as “PFMT pointer”) indicating the position of data to be read next in each buffer.

  That is, in the pointer control field, how to control the PFMT pointer after the buffer data is processed by a data control command described later in the data processing command is set. Then, control such as incrementing the PFMT pointer and moving the PFMT pointer to the designated area is performed in accordance with the set contents.

  If the number of repetitions is set to 2 or more in the repeat field, the pointer control field increments the PFMT pointer until the last repetition and moves the PFMT pointer to the designated area at the last repetition. Can be set.

  Further, when processing a buffer other than WMRB with a data processing command, a pointer control field can be set so as not to move the PFMT pointer in order to repeatedly process one area of the buffer.

  The WMRB has a write pointer (hereinafter referred to as “PHST pointer”) indicating the head position of the unused position, and is managed by the buffer controller 52 described later together with the PFMT pointer. As a reference, FIG. 3 shows an example of a PHST pointer and a PFMT pointer when data is accumulated in areas 4 to 6 of the WMRB. The difference between the PHST pointer and the PFMT pointer is the number of areas of data stored in the WMRB, and in the case of FIG.

  In the data control field, it is set how to format each piece of data stored in the data storage device 10 in units of areas.

  The contents of the format processing relate to data generation according to the format of the recording medium. For example, in the case of a CD (Compact Disc), SYNC (synchronization signal) is generated at the time of recording, HEADER is generated, and the like.

  Here, the command storage device 20 has a command control device 21. The command control device 21 generates a data remaining amount table as shown in FIG. 7 from the WMRB identifier field and the repetition count field of the data processing command written in the command storage device 20.

  In the data remaining amount table, as shown in FIG. 7, the number of WMRB areas (hereinafter referred to as “WMRB data remaining amount”) processed by one data processing command related to WMRB for each row and outside the WMRB. The number of areas outside the WMRB buffer to be processed by one data processing command relating to the buffer (hereinafter referred to as “outside WMRB data remaining amount”) is arranged in the order of execution.

  The command control device 21 detects whether the data processing command is for the WMRB or the buffer outside the WMRB from the value of the WMRB identification field of the data processing command, and one data processing command processes it. The number of buffer areas is detected from the value of the repetition number field of the data processing command.

  The data access device 30 accesses the data storage device 10 according to an instruction from the control device 50 or the CPU 60 and writes or reads each data in the data storage device 10.

  Access to the data storage device 10 may be either a buffer type indicating either WMRB or outside the WMRB, a buffer area number, writing to the buffer (hereinafter referred to as “write access”), or reading from the buffer ( Hereinafter, it is referred to as “read access”).

  In addition, when providing a field in the data of each area, it carries out by adding a field identification signal to the signal which accesses the data storage device 10. FIG.

  The command access device 40 reads data stored in the command storage device 20, writes commands to the command storage device 20, remaining WMRB, remaining outside WMRB, etc., according to instructions from the control device 50 or CPU. Is read out.

  Command reading from the command storage device 20 is performed by the control device 50 specifying the area number of the command to be read. That is, when an area number of a command is specified from the control device 50, the command access device 40 reads out the command of the specified area number from the commands stored in the command storage device 20, and reads the read command to the control device 50. Forward to.

  Furthermore, it is possible to extract only a part of the command field from the command storage device 20 by designating the field. That is, when an area number and a field are specified from the control device 50, the command access device 40 retrieves the value of the specified field from the command of the specified area number from the command storage device 20 and transfers it to the control device 50. .

  When the command access device 40 receives a command for reading the remaining WMRB and the remaining amount outside the WMRB from the control device 50, the command access device 40 reads the remaining WMRB and the remaining amount outside the WMRB at the PCMD pointer position described later from the command storage device 20, and performs control. Transfer to device 50.

  On the other hand, the command is written to the command storage device 20 by the CPU 60 designating a plurality of data processing commands generated by the CPU 60 in accordance with the recording contents on the recording medium. , By writing to the command storage device 20.

  When the writing of the data processing command is completed, the command control device 21 in the command storage device 20 calculates the WMRB remaining amount and the WMRB remaining amount.

  The control device 50 includes therein a data processing device 51, a buffer control device 52, and a buffer underrun management device 53.

  The data processing device 51 has a function of processing the area unit data retrieved from the data storage device 10 according to the information in the data control field of the data processing command.

  The buffer control device 52 has functions such as management of pointers, management of commands, and management of remaining data, details of which will be described later.

  For example, the buffer control device 52 can read the remaining WMRB data and the remaining WMRB data from the command control device 21, and further displays a PCMD pointer indicating to which line in the remaining data table the remaining data has been referenced. to manage.

  The buffer underrun management device 53 receives the remaining data amount from the buffer control device 52, and performs a buffer underrun processing operation when the remaining data amount becomes equal to or less than a value preset by the CPU 60.

  The buffer underrun processing operation includes a burn-proof function operation.

  The CPU 60 performs initial setting and activation of each device according to its internal program (hereinafter referred to as “firmware”), and processing according to an interrupt such as a buffer underrun processing operation. Further, the CPU 60 accesses the data storage device 10 via the data access device 30 or accesses the command storage device 20 via the command access device 40.

  The operation of the data control apparatus 1 configured as described above will be described with reference to the flowcharts of FIGS.

  Note that S1 to S4 and S9 are processes in the firmware of the data control apparatus 1, and S5 to 8 and S10 to S23 are processes in the hardware of the data control apparatus 1.

  First, the CPU 60 initializes the entire data control device 1. That is, by outputting a reset signal to the data storage device 10, the command storage device 20, the data access device 30, the command access device 40, and the control device 50, each of these devices is initialized.

  Further, the CPU 60 sets pointers such as PFMT, PHST, and PCMD and registers such as REMARA, HSTCNT, TMPA, and TMPB to initial values, that is, “0” (S1).

  Here, the PCMD pointer is a pointer indicating the unreferenced WMRB remaining amount and the WMRB remaining amount position in the data remaining amount table of the control device 50.

  REMARA is a register indicating the number of areas of data that can be stored in the data storage device 10 and can be processed. That is, the number of data areas that can be output to a recording medium without data transfer from the host to the WMRB.

  TMPA is a register indicating the number of times of processing of the WMRB data area of the data processing command to be processed next with respect to WMRB, and TMPB is a data area of the WMRB external buffer of the data processing command to be processed next with respect to the WMRB external buffer. Is a register indicating the number of times of processing.

  HSTCNT is a register indicating the number of areas in which data transferred from the host is accumulated in the WMRB in units of areas.

  Next, the CPU 60 generates a plurality of data processing commands according to the contents recorded on the recording medium, and writes these data processing commands to the command storage device 20 via the command access device 40.

  Based on the data processing command, the command control device 21 generates a data remaining amount table as shown in FIG. 7 from the WMRB identifier field and the repetition count field of the data processing command written in the command storage device 20.

  Further, the CPU 60 generates WSRB and WLB data corresponding to the content to be recorded on the recording medium, and accumulates the generated data in the WSRB and WLB of the data storage device 10 via the data access device 30 (S2).

  Next, the CPU 60 sets a PHST pointer and a PFMT pointer for each buffer of the data storage device 10 (S3). At this time, since the data stored in each buffer is not processed at all, the PHST pointer and the PFMT pointer have the same value.

  When the processing up to S3 is completed, the CPU 60 executes the INIT command (S4). Here, the INIT command is a command for reading the remaining WMRB and the remaining WMRB and setting the initial value of REMARA.

  Next, in S5-8, the hardware operation of the data control device is performed in accordance with the INIT command.

  That is, the buffer control device 52 reads the remaining WMRB and the remaining WMRB remaining at the PCMD pointer position via the command access device 40, and increments the PCMD pointer (S5). The remaining amount outside WMRB is set to TMPA and TMPB, respectively (S6).

  Next, the buffer control device 52 determines whether or not the value of TMPA is 0 (S7). That is, the buffer control device 52 determines whether or not the remaining amount of WMRB read in S5 is zero. If it is determined that the remaining WMRB is 0, after adding the value of TMPB to REMARA (S8), the buffer control device 52 repeats the operation from S4 again, while determining that the remaining WMRB is not 0. Then, initialization is completed, and the CPU 60 operates each device to start data transfer from the host and format processing (S9). Note that the data transfer from the host and the start of the format process do not necessarily have to be started at the same time.

  Thereafter, the remaining amount of data and the pointer are updated in accordance with the data transfer from the host and the format processing status (S10 to S23).

  First, the control device 50 determines whether or not the content to be processed is data transfer from the host (S10).

  When the control device 50 determines that the content to be processed is data transfer from the host, the buffer control device 52 stores the data for one area received from the host via the data access device 30 as data storage. The PHST pointer is updated for one area by accumulating in the WMRB of the apparatus 10 (S11).

  Next, the buffer control device 52 increments HSTCNT (S12), and determines whether HSTCNT has the same value as TMPA (S13). If it is determined that HSTCNT has the same value as TMPA, execution of a data processing command outside the WMRB to be processed next is determined. That is, since it becomes data that can be continuously output to the recording medium together with the data accumulated in the WMRB, the buffer control device 52 adds the value of TMPB to the value of REMARA and increments it (S14).

  Next, the buffer control device 52 reads the WMRB data remaining amount and the WMRB remaining data amount at the position of the PCMD pointer, and increments the PCMD pointer (S15).

  Then, the buffer control device 52 sets the read WMRB data remaining amount and the WMRB remaining data remaining amount to TMPA and TMPB, respectively (S16).

  Further, the buffer control device 52 sets HSTNCT to 0 and repeats the operation from S10 (S17).

  On the other hand, if the buffer controller 52 determines in step S13 that HSTCNT is not the same value as TMPA, REMARA is incremented and the operation from step S10 is repeated (step S18).

  Further, the control device 50 determines whether or not the content to be processed is the format processing of the data recorded in the data storage device 10 (S19).

  When it is determined that the content to be processed is format processing, the buffer control device 52 retrieves data for one area at the PFMT position from the data storage device 10 via the data access device 30, and updates the PFMT. To do. The extracted data is formatted by the data processing device 51 according to the contents of the data control field of the data processing command, and transmitted to the recording medium via the encoder (S20).

  Next, the buffer control device 52 decrements REMARA (S21), and determines whether or not the next data processing command is an end command (S22).

  If it is determined in S22 that the next command is an end command, the control device 50 ends the buffer control operation (S23). If it is determined not to be an end command, the control device 50 repeats the operation from S10.

  In the following, the flow of FIGS. 4 and 5 will be described with reference to FIGS. Here, FIG. 6 is a diagram showing an example of the generated data processing command, FIG. 7 is a diagram showing an example of the remaining data table, and FIG. 8 is a diagram showing the remaining data calculation device.

  Here, the remaining data calculation device mainly includes a command recording device 20 and a buffer control device 52.

  Note that CD packet write is a recording method in which data transmitted from a host is divided into packet units, and link data is generated and added for each packet unit.

  The packet unit data is WMRB data for 16 areas, and the link data is WSRB data for 7 areas.

  First, when the initial reset is completed in S1, a data processing command is generated and stored in the command storage device 20 in S2 as shown in FIG. Note that the command processing is performed in order from the data processing command 0. Further, the buffer control device 52 creates a data remaining amount table as shown in FIG. 7 from the WMRB identifier field and the repetition number field of this data processing command. In S5 to S8, the WMRB remaining amount at the PCMD pointer position where the WMRB remaining amount is not 0 and the remaining amount outside the WMRB, that is, the WMRB remaining amount 16 at the second row position from the bottom of the data remaining amount table (data processing command 0) The number of repetitions 16) and the remaining amount 7 outside the WMRB (the number of repetitions 7 of the data processing command 1) are read, TMPA is set to 16, TMPB is set to 7, and the PCMD pointer is set to the third line from the bottom. Incremented to position.

  Thereafter, when the data transfer from the host is processed, that is, accumulated in the WMRB buffer, REMARA is incremented (S18). On the other hand, after one area of data in the data storage device 10 has been taken out for recording on the recording medium. When the formatting process ends, REMARA is decremented (S21), and the remaining WMRB data is detected by REMARA.

  If the same number of data transfers from the host as TMPA are processed in S13, it means that data for 16 areas of WMRB to be processed by data processing command 0 has been received, while 7 outside the WMRB to be processed by data processing command 1 is received. Since data for the area has already been prepared in S2, processing up to the data processing command 1 can be executed. Therefore, the number of data areas outside the WMRB to be processed by the next data processing command 1 is added to REMARA in S14.

  Next, the WMRB remaining amount and the WMRB remaining amount at the PCMD pointer position, that is, the WMRB remaining amount 16 (the number 16 of repetitions of the data processing command 2) and the remaining WMRB remaining amount 7 at the third row from the bottom of the data remaining amount table. (Repetition number 7 of data processing command 3) is read out, the PCMD pointer is incremented to the position of the fourth row from the bottom, and TMPA is set to 16 and TMPB is set to 7 in S15.

  Similarly, when data for the number of data areas to be processed by the data processing command 2 is transferred from the host and data for 16 areas to be processed by the data processing command 2 is accumulated in the WMRB, the processing of the data processing command 3 is confirmed. 7 areas are added to REMARA to enable execution.

  As described above, after starting data accumulation in the data storage device 10, the buffer control device 52 detects the number of areas of data accumulated in the WMRB and can process the data of the number of areas. Is detected. Then, the buffer control device 52 detects the number of data areas that can be continuously output to the recording medium together with the data stored in the WMRB out of the data stored outside the WMRB. More specifically, a data processing command required to output all data data stored in the WMRB to the recording means among data processing commands for the WMBR external buffer is detected, and data to be processed by this data processing command is detected. Detect the number of areas. Then, the remaining data amount is calculated by adding the detected number of areas and the number of data areas accumulated in the WMRB.

  That is, the buffer controller 52 detects the number of areas detected by the first detection means among the means for detecting the number of areas of data stored in the first buffer and the data processing command for the second buffer. Means for detecting a data processing command required to output all data to the recording means, detecting the number of data areas to be processed by the detected second data processing command, and the number of areas detected by these means; To the third detecting means for detecting the remaining amount of data, and the data stored in the data storage device 10 can be continuously processed without data transfer from the host to the WMRB. The remaining amount of data can be calculated.

  Next, the operation of the buffer underrun process of the data control apparatus according to the embodiment of the present invention will be described with reference to FIG. Note that the operations of the initial operation (S30) and the activation of each device (S31) are the same as the operations of S1 to S8 and S9 in FIG.

  When the initial operation and the activation of each device are completed, until the processing corresponding to the recorded contents is completed (S32), the REMARA register indicates whether or not the remaining buffer capacity of data that can be processed is less than a predetermined value, that is, the buffer underrun state. (S33).

  If it is determined that the buffer underrun has occurred, processing corresponding to the buffer underrun is performed (S34).

  As described above, according to the data processing device of the present embodiment, the number of areas of unprocessed data in the data storage device that can be actually executed can be accurately detected, so that erroneous detection of buffer underrun can be avoided. Can do.

  Therefore, by performing unnecessary buffer underrun handling processing, it is possible to prevent performance degradation due to unnecessary processing.

  In addition, since the data processing command has a repetition number field, even when the same control command is executed multiple times, it is not necessary to write the data processing command to the command storage device multiple times, thereby improving the performance of the write processing. And the memory capacity of the command storage device can be reduced.

  Further, even when it is necessary to modify the data control command stored in the command storage unit, the command storage device uses the repetition number field to collectively store the same control command as one data processing command. Thus, the amount of access to the command storage device can be reduced. In particular, when the command storage device is an SDRAM, the processing performance can be improved.

  Further, the method of reading the pointer control command of each data processing command and calculating the remaining amount of data that can be executed by WSRB or WLB is difficult to process in real time. In the data control device in FIG. 3, the number of areas of unprocessed data that can be processed in WSRB or WLB can be calculated and added from the number of areas of unprocessed data in WMRB without using a pointer control command. Real-time processing is possible.

  Note that some fields of the data processing command, for example, the repetition number field may be reduced. In this case, in the data processing command group generated by the CPU, each data control command is accumulated in the command storage device as a data processing command for the number of repetitions, and a data remaining amount table is generated. However, the operation is the same as that described above except for the number of repetitions.

Configuration diagram of a data control apparatus according to an embodiment of the present invention Configuration diagram of data processing command in the embodiment of the present invention The figure which shows the example of the PHST * PFMT pointer in embodiment of this invention The flowchart which shows data remaining amount detection operation in embodiment of this invention The flowchart which shows data remaining amount detection operation in embodiment of this invention The figure which shows the example of the data processing command produced | generated in embodiment of this invention The figure which shows the example of the data remaining amount table | surface in embodiment of this invention The figure which shows the data remaining amount calculation apparatus in embodiment of this invention The flowchart which shows the buffer underrun detection operation in embodiment of this invention

Explanation of symbols

1 Data Controller 10 Data Storage Device 20 Command Storage Device 21 Command Control Device 30 Data Access Device 40 Command Access Device 50 Control Device 51 Data Processing Device 52 Buffer Control Device 53 Buffer Underrun Processing Device 60 CPU

Claims (5)

A first buffer that sequentially stores data transmitted from the computer device in units of areas, and a second buffer that sequentially stores data generated in accordance with the recording processing content to the recording medium in units of areas; A data control device that extracts data in units of areas from the first or second buffer based on a plurality of data processing commands generated according to the content of the recording processing, and outputs the data to the recording medium,
First detection means for detecting the number of areas of data stored in the first buffer;
Second detection means for detecting the number of areas based on the number of areas detected by the first detection means among the number of areas of data stored in the second buffer;
A data control apparatus comprising: third detection means for detecting a remaining amount of data from the number of areas detected by the first detection means and the number of areas detected by the second detection means.   The detection of the number of areas in the second detection means is to detect the number of areas of data that can be continuously output to the recording medium together with the data of the number of areas detected by the first detection means. The data control device according to claim 1.   The detection of the number of areas in the second detection means is necessary for outputting all the data of the number of areas detected by the first detection means to the recording means among the data processing commands for the second buffer. 2. The data control apparatus according to claim 1, wherein a data processing command is detected and the number of areas of data to be processed by the detected second data processing command is detected. The data processing command has an identifier field for identifying whether the data processing command is for the first buffer or the second buffer, and a repetition number field indicating the number of areas of data to be processed,
4. The data control apparatus according to claim 3, wherein the second detection unit detects the number of areas from information in the identifier field and the repetition number field. A first buffer that sequentially stores data transmitted from the computer device in units of areas, and a second buffer that sequentially stores data generated in accordance with the recording processing content to the recording medium in units of areas; Based on a plurality of data processing commands generated according to the contents of the recording process, a method for detecting the remaining amount of buffer data in the apparatus that extracts data from the first or second buffer in units of areas and outputs the data to the recording medium Because
A first step of detecting the number of areas of data stored in the first buffer;
A second step of detecting the number of areas based on the number of areas detected in the first step among the number of areas of data stored in the second buffer;
A buffer data remaining amount detecting method comprising: a third step of detecting a remaining amount of data from the number of areas detected in the first step and the number of areas detected in the second step.

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