JP2005317108A - Data processor - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a data processor capable of continuously reproducing the reading information from external memories such as a medium disk. <P>SOLUTION: This data processor is equipped with a processor 11 for reading out the data from a disk-like recording medium 1 storing the data and processing these data, a 1st buffer memory 12 accessed by the processor 11 to store the processed data of the processor 11, and a 2nd buffer memory 13 accessed by the processor 11 at an access speed faster than the access speed to the disk-like recording medium 1 and slower than the access speed to the 1st buffer memory 12. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a data processing apparatus, and more particularly to a data processing apparatus suitable as an apparatus for storing and reproducing information read from a medium disk or the like, and further to an effective data processing apparatus provided in a navigation system.

  A conventional data processing apparatus of this type is known as a recording / reproducing apparatus as shown in FIG. This apparatus includes a pickup 31, an analog-digital converter (hereinafter simply referred to as an AD converter) 33, a compression circuit 34, a recording buffer memory 35, an encoder 36, and a recording circuit 37 as components constituting the information recording unit. As a component constituting the information reproducing unit, a reproducing circuit 38, a decoder 39, a reproducing buffer memory 40, an expansion circuit 41, and a digital / analog converter (hereinafter simply referred to as a DA converter) 42 are provided, and a CPU 43 for controlling them is further provided. (See, for example, Patent Document 1).

  Input data Sin from the outside is converted into a digital signal by the AD converter 33, compressed by the compression circuit 34, and temporarily stored in the recording buffer memory 35. The accumulated data is compressed and encoded by the encoder 36 and sent to the recording circuit 37 as encoded information. In the recording circuit 37, the encoded information is written to the medium disk 30 in accordance with a predetermined write control signal from the CPU 43.

Information recorded on the medium disk 30 is read into the reproduction circuit 38 via the pickup 31, decrypted by the decoder 39, temporarily stored in the reproduction buffer memory 40, and sequentially taken into the expansion circuit 41 for expansion. The analog signal is output from the DA converter 42.
JP-A-11-273246

  In the conventional recording / playback apparatus as described above, the write information (for example, music information) of the removable medium disk 30 is optically read through the pickup 31, so that it is under a vibration environment as in the case of being mounted on a vehicle. When reading is performed at, the read state tends to become unstable.

  However, the storage capacity value of the reproduction buffer memory 40 is considerably smaller than the storage capacity value of the medium disk 30, and the data transfer rate of the reproduction buffer memory 40 is considerably larger than the reading speed from the medium disk 30 side. . Therefore, reading from the medium disk at the time of reproduction becomes unstable, and the encoding process is interrupted, so that high-speed ripping cannot be performed, or reproduction such as skipping occurs during reproduction output using the AAC decoder. There is a problem that it is easy.

  The present invention has been made to solve such a conventional problem, and an object thereof is to provide a data processing apparatus capable of processing and reproducing information read from an external memory such as a medium disk without interruption.

  To achieve the above object, a data processing apparatus according to the present invention includes a processor that reads data from an external memory that stores data and processes the data, and a first buffer that is accessed by the processor and stores processing data of the processor And a second buffer memory accessed by the processor at an access speed greater than an access speed to the external memory and less than an access speed to the first buffer memory. is there.

  With this configuration, even when data reading or transfer input from the external memory is likely to be interrupted, data can be temporarily stored in the second buffer memory having a higher access speed than the data input, and data reading from the external memory can be performed. Even if the transfer input is temporarily interrupted, the high-speed data processing using the first buffer memory can be continuously executed while the influence is absorbed by the second buffer memory.

  In the data processing apparatus of the present invention, it is preferable that the second buffer memory is a storage device having a storage capacity larger than that of the first buffer memory.

  With this configuration, the access speed is faster than the speed of reading and transferring data from the external memory, and there is room for input data such as read data in the second buffer memory having a larger storage capacity value than the first buffer memory. Even if data reading from the external memory or transfer input is temporarily interrupted, the second buffer memory absorbs the influence of the data and the high speed using the first buffer memory. Data processing can be continued.

  Further, if the second buffer memory is a fixed storage device such as a hard disk or a solid-state memory card, problems such as outside air and dust getting into the reading unit and reading being unstable due to vibration can be avoided. In other words, the second buffer memory can be effectively used as a shock proof memory together with the first buffer memory.

  In the data processing apparatus of the present invention, the storage device may be a removable storage device that can be attached and detached.

  With this configuration, it is possible to easily switch the storage capacity of the second buffer memory in response to the expansion of the usage of the apparatus and the increase in the capacity of the external memory.

  The present invention temporarily stores input data by the second buffer memory having a higher access speed than the data input from the external memory, and even if the data input from the external memory is temporarily interrupted, Since it is possible to continue high-speed data processing such as ripping using the first buffer memory while absorbing with the buffer memory of 2, the reading of the removable disk-shaped recording medium etc. is likely to become unstable, in a vibration / impact environment, For example, it is possible to provide a data processing apparatus that can effectively prevent interruption of reproduction information such as skipping sound even in a vehicle that is traveling off-road.

  Hereinafter, an embodiment of the present invention will be described with reference to the drawings.

  In the present embodiment, the data processing apparatus of the present invention is applied to a recording / reproducing apparatus (hereinafter simply referred to as a recording / reproducing apparatus) of an in-vehicle navigation system.

  As shown schematically in FIG. 1, the recording / reproducing apparatus of the present embodiment reproduces, compresses and stores read data from the disk-shaped recording medium 1 (external memory) and input data from another external memory. A multi-thread processor 11, a first buffer memory 12 accessed by the processor 11, and a second buffer memory 13 accessed by the processor 11 are provided.

  The disc-shaped recording medium 1 is a removable recording medium for storing predetermined data, and is composed of, for example, an optically readable CD (Compact Disc), a DVD (Digital Versatile Disc), or other optical disks. The data recorded on the disc-shaped recording medium 1 is PCM digital audio data such as CD-DA (Compact Disc Digital Audio), but may be MP3 (MPeg audio layer 3) compressed data or include image data. However, it is not particularly limited. Further, the disc-shaped recording medium 1 is not limited to an optical disc, and an attaching / detaching method in which the transfer rate of read data must be slower than either the first buffer memory 12 or the second buffer memory 13 ( It is a removable data recording medium.

  Data recorded on the disk-shaped recording medium 1 is read by a CD / DVD deck or other disk drive 10 and transferred and output at a predetermined data transfer speed. That is, the disk drive 10 is a means for inputting and transferring data from an external memory. The disk drive 10 is capable of not only reproducing data recorded on a disk-shaped recording medium 1 such as a CD or a DVD, but also writing data on a disk-shaped recording medium 1 of a predetermined format such as a write-once type.

  The processor 11 has a microcomputer configuration including a CPU, a memory, and an interface. In processing the data, the processor 11 exchanges data to be processed with the first buffer memory 12 and the second buffer memory 13. The disk drive 10 is also made to execute a direct memory access type data transfer process (hereinafter simply referred to as DMA transfer).

  The first buffer memory 12 stores data used for data processing in the processor 11 in a readable manner, and exchanges data with the processor 11 being processed. The first buffer memory 12 is composed of a semiconductor memory element that functions as a high-speed buffer memory having a data storage capacity of, for example, about 2 megabytes.

  The processor 11 is temporarily stored in a first storage area (described later) of the second buffer memory 13 in a data format at the time of reading that can normally reproduce the read data in response to a reproduction request input, for example, a PCM digital audio data format. A reading function thread T1 that stores data, an encoding function thread T2 that performs compression encoding processing of read data, for example, AAC (Advanced Audio Coding) encoding processing in response to a recording request input, and one piece of encoded data, for example, Are stored in a second storage area (to be described later) of the second buffer memory 13 as a music data file, and in this case, an accumulation recording function thread T3 for recording, and a reproduction request input to the second buffer memory 13 Based on temporarily stored data, eg PCM digital audio data The first reproduction function thread T4 for outputting audio and the data that has been encoded and accumulated and recorded in the FAT area of the second buffer memory 13, for example, an AAC data file for one song, are read and decoded so as to be reproducible. The decoding function thread T5 is executed, and a plurality of other threads, for example, updating the vehicle position information on the navigation map, search processing, video reproduction, human machine interface (hereinafter referred to as HMI) operation, etc. A thread can be executed.

  The second buffer memory 13 includes an LBA area as a first storage area from which recorded information can be quickly read out by logical block address management, and a predetermined file handled by one or more predetermined operating systems (OS). It has a FAT (File Allocation Table) area as a second storage area for recording and saving the file information of the format in a readable manner.

  Specifically, for example, as shown in FIG. 2, the second buffer memory 13 includes a read-only first LBA area A1, a map data FAT area A2, a music data TFAT (Transaction-safe FAT) area A3, and an HMI. It has a data FAT area A4 and a work area A5 which is a ripping PCM data storage area. In the TFAT area, encoded AAC data is recorded so as to be readable in the file format of the TFAT file system. The TFAT file system is intended to prevent the loss of transaction data on a memory card or hard disk when the power supply is reduced.

  The data transfer rate of the second buffer memory 13 is, for example, about 10 megabytes per second to 30 megabytes per second. This rate is the transfer rate of read data from the disk drive 10 (access speed to external memory; for example, 170 kilobytes per second) To 1.7 megabytes per second) and less than the access speed to the first buffer memory 12. That is, the data writing speed and the data reading speed that are the access speed of the second buffer memory 13 are faster than the transfer speed of the read data from the disk drive 10 and the data transfer speed of the first buffer memory 12 (for example, 200 Megabytes per second) or slower.

  The second buffer memory 13 is composed of a storage device having a storage capacity larger than that of the first buffer memory 12, such as a hard disk drive or a memory card having excellent vibration resistance. The hard disk here is a small one that can be mounted on a portable information device, and the memory card here is a card-like or stick-like one containing a semiconductor memory element of about the size of a PC card or less. . The term “fixed recording medium” as used herein means that a medium that stores information is not separated from the main body of the apparatus that reads information on the medium. However, as a whole device, the second buffer memory 13 is configured as a storage device that can be attached to and detached from the casing (not shown) of the navigation system, and exchanged, repaired, or previously stored compressed data. A storage device can be installed in a replaceable manner.

  Next, with reference to FIG. 2, a general flow of data related to storage, compression and accumulation recording, and reproduction of read data in the recording / reproducing apparatus of the present embodiment will be described.

  The CD-DA data recorded on the disk-shaped recording medium 1 is read by the disk drive 10 equipped with the ATAPI driver in response to a request from the reading function thread T1 of the processor 11, and is about 170 kilobytes to 1.7 megabytes, for example. DMA (Direct Memory Access) transfer is output at a predetermined data transfer rate. This data flow is indicated by an arrow da in FIG.

  The read data transferred and output here is, for example, in the second LBA area A5 of the second buffer memory 13 with the data of one track of the recording track on the disk-shaped recording medium 1 (hereinafter referred to as track data) as a writing unit. Written to multiple logical blocks. Such data is written (stored) in the second buffer memory 13 on the disk-shaped recording medium 1 while sequentially assigning logical block addresses in the order of track numbers as indicated by TRK1, TRK2, and TRK3 in FIG. This is executed for the data of all recording tracks.

  Therefore, after the writing is completed, the processor 11 can read arbitrary track data from the second buffer memory 13 by designating the logical block address in the second LBA area A5.

  The stored data is read from the second buffer memory 13 based on the address information for each data writing unit, data reading for AAC encoding processing (indicated by an arrow db in FIG. 1), A plurality of read paths for reproduction output (indicated by arrow dc in FIG. 1) for using PCM data of another track different from the track for reproduction output are prepared.

  When this stored data is read, encoding processing by the encoding function thread T2 of the processor 11 is executed, and AAC data of a predetermined file size is sequentially stored and recorded in the second buffer memory 13 by the storage recording function thread T3 of the processor 11 (FIG. 1). (Indicated by arrow de). On the other hand, the first playback function thread T4 of the processor 11 sequentially uses the track data in the PCM data format as it is read and outputs the desired music piece.

  Further, the audio data stored in the second buffer memory 13 is appropriately decoded by the decoding function thread T5 of the processor 11 in accordance with the reproduction request input, and the reproduced sound is output by the amplifier 15 and the speaker 16.

  In such a recording / reproducing apparatus of the present embodiment, even when data reading from the disk-shaped recording medium 1 and transfer input are easily interrupted, the data is temporarily stored in the second buffer memory 13 whose access speed is faster than the data input. The first buffer memory 12 is used while the data can be stored, and even when data reading from the disk-shaped recording medium 1 and transfer input are temporarily interrupted, the second buffer memory 13 absorbs the interruption. High-speed data processing, for example, compression encoding processing can be continuously executed.

  The second buffer memory 13 is configured by a storage device having a storage capacity (for example, about 700 to 1 gigabyte) larger than the storage capacity (for example, about 2 megabytes) of the first buffer memory 12, and is a medium speed buffer memory. Therefore, the second buffer memory 13 having a higher access speed than the speed of reading and transferring data from the disk-shaped recording medium 1 and having a larger storage capacity value than the first buffer memory 12, Input data such as read data can be stored with a sufficient margin, and data reading and transfer input from the disk-shaped recording medium 1 is temporarily performed due to impact or vibration of the vehicle or dust adhering to the disk-shaped recording medium 1. Even if it is interrupted, it can be reliably absorbed by the second buffer memory 13, and , It can be performed to continue high-speed data processing using the first buffer memory 12.

  In the present embodiment, since the second buffer memory 13 is a fixed storage device such as a hard disk or a solid-state memory card, outside air or dust may enter the reading unit, or reading may become unstable due to vibration. This is effective in using the second buffer memory 13 together with the first buffer memory 12 as a shock proof memory.

  Furthermore, in the present embodiment, the storage device that constitutes the second buffer memory is a removable storage device that can be attached and detached. Therefore, the application of this apparatus can be expanded (for example, an option can be added), the disk-shaped recording medium 1 or the like. The storage capacity of the second buffer memory 13 can be easily switched in response to the increase in the capacity of the external memory, and can fully meet various required specifications.

  As described above, the data processing apparatus according to the present invention is such that the disk sound skips even in a vibration / impact environment in which reading of a removable disk-shaped recording medium tends to be unstable, for example, in a vehicle running off-road. Therefore, the present invention is useful as an apparatus for accumulating and reproducing music information read from a medium disk or the like, and as a part of a navigation system.

The block diagram which shows schematic structure of the data processor in one embodiment of this invention Explanatory drawing explaining the structure of the storage area of the 2nd buffer memory in one embodiment of this invention Block diagram showing the configuration of a conventional recording / playback apparatus

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Disc-shaped recording medium 11 Processor 12 1st buffer memory 13 2nd buffer memory A1 Read-only 1st LBA area A2 FAT area for map data A3 TFAT (Transaction-safe FAT) area for music data A4 FAT area for HMI data A5 Work area which is PCM data storage area for ripping

Claims (3)

A processor that reads data from an external memory that stores data and processes the data;
A first buffer memory that is accessed by the processor and stores processing data of the processor;
A data processing apparatus comprising: a second buffer memory that is accessed by the processor at an access speed that is greater than an access speed to the external memory and less than an access speed to the first buffer memory. The data processing apparatus according to claim 1, wherein the second buffer memory is a storage device having a storage capacity larger than a storage capacity of the first buffer memory. The data processing apparatus according to claim 2, wherein the storage device is a detachable removable storage device.

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