JP2000331416A - Audio video reproducing device and firmware changing system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To enable the easy change of a firmware in an electrically erasable nonvolatile memory in an audio/video reproducing device and also to display the picture desired by the user in the audio/ video reproducing device provided with the picture display function. SOLUTION: The content of a CD whereon the firmware is housed in a sub-code part is reproduced. Data of the reproduced sub-code are read out in the amount of one data block to a buffer by a microprocessor 503. When the judgment is made that the firmware is to be written in and no data error exists, the firmware content is written into a nonvolatile memory 504. Otherwise, the picture data of the video CD 501 in the process of reproduction are recorded in the nonvolatile memory by the microprocessor and displayed as picture data.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a firmware changing method for an audio / video reproducing apparatus including a microprocessor having firmware stored in an electrically erasable nonvolatile memory.

[0002]

2. Description of the Related Art Conventionally, to change firmware in an electrically erasable nonvolatile memory, a dedicated rewriting device and an audio / video reproducing device itself need an interface with the rewriting device. Rewriting requires a field service technician with special operations and knowledge. FIG. 14 is a configuration diagram necessary for a conventional writing method. In FIG. 14, reference numeral 1401 denotes a digital audio / video recording medium, and 1402 denotes an audio / video reproducing unit. Reference numeral 1403 denotes a memory microprocessor for controlling the audio / video reproduction unit 1402, reference numeral 1404 denotes an electrically erasable nonvolatile memory storing firmware of the microprocessor 1403, and reference numeral 1405 denotes a dedicated rewriting device 1407.
1406 is a switch for reading and judging whether or not to perform a rewriting operation by the microprocessor 1403. 1407 is an audio / video reproduction through the rewriting interface 1405. A dedicated rewriting device for connecting to the device,
Is the dedicated rewriting device 1407 to the nonvolatile memory 1404
Is the firmware data for rewriting to be written to.

A dedicated rewriting device 1407 is connected to a rewriting interface 1405, and a mode changeover switch 14
06, the microprocessor 14
03 waits for the reception of the rewriting firmware data 1408 from the rewriting interface 1405. In this state, transmission of the rewriting firmware data 1408 from the dedicated rewriting device 1407 is started.
Upon receiving the rewriting firmware data 1408 of the microprocessor 1403, the received data is written to the nonvolatile memory 1404.

[0004] Further, the image displayed on the image display device 1409 at the time of reproducing the audio recording medium or at the time of stopping the reproduction is always a fixed image.

[0005]

Conventionally, when the firmware in the electrically erasable non-volatile memory in the audio / video reproducing apparatus can be changed, the audio / video reproducing apparatus has a rewriting interface and mode switching. Hardware resources such as switches, which are not originally required for the audio / video reproducing apparatus, and a dedicated rewriting apparatus are required, and the rewriting method is complicated.
When an audio / video playback device having an image display function plays back a recording medium on which only audio data is recorded, the image display function of the audio / video playback device is not used and the audio / video playback device is internally provided. The image is not displayed by the user who has it, or the image is not displayed at all.

SUMMARY OF THE INVENTION The present invention solves the above-mentioned conventional problems. An audio / video playback device includes hardware resources such as a rewrite interface and a changeover switch, which are not necessary for an audio / video playback device, and a dedicated rewrite device. An object of the present invention is to provide a method of changing firmware and an image of an audio / video playback device, which is unnecessary and can simplify the trouble of changing the firmware in the nonvolatile memory.

[0007]

In order to achieve this object, a method for changing the firmware of an audio / video reproducing apparatus according to the present invention comprises: a digital audio / video recording medium on which rewriting firmware data is recorded as digital information; It comprises an audio / video reproduction module capable of reproducing digital information, a microprocessor capable of reading the reproduced digital information, and a nonvolatile memory in which the microprocessor can be rewritten.

With the above configuration, the firmware in the nonvolatile memory can be changed only by reproducing the digital audio / video recording medium in which the rewriting firmware data is recorded as digital information.

[0009]

(Embodiment 1) The first embodiment of the present invention will be described below with reference to the drawings. Generally, in a format of an audio signal handled by a digital audio recording medium or the like, there is an area called a subcode for recording sub-information such as graphic information and character information in addition to an audio signal serving as main information. Here, the signal format of a compact disc as a digital audio recording medium will be described with reference to the drawings. As shown in FIG. 1, the signal format of the digital audio recording medium described above constitutes a unit called a frame, which is the minimum unit of information, and 98 frames constitute one block. One frame has an audio signal of 6 channels each for Lch and Rch.
Each sample (16 bits per sample) is composed of 24 bytes of data, and the subcode is composed of 1 byte of data. Therefore, the subcode has 98 bytes in one block.

FIG. 2 is a diagram for explaining a format of a subcode of a digital audio disc. S0 and S1 of 2-byte data that is the first two frames of the block
Is used as a synchronization signal of the subcode itself. Therefore, 96 bytes of 3 frames or less are used as the sub information data. The sub-code having 8 bits (1 byte) per frame has P, Q, R, S,
They are called T, U, V, W channels. The P channel is used to indicate the position of the beginning of a song of an audio signal that is main information, and is particularly used for rough cueing. As shown in FIG. 3, the Q channel has a control code at the top 4 bits, an address code at the next 4 bits, and 1 bit from the end.
Six bits are a code of an error detection signal of a cyclic code which is a CRC (Cyclic Redundancy Code), and the remaining 72 bits are data. The R to W channels are user channels and can record sub-information such as graphic information and character information.

FIG. 4 shows a data unit in which the microprocessor processes the data of the subcodes R to W channels. One data block is composed of a sync code indicating the beginning of the data block, firmware data to be written into an electrically erasable nonvolatile memory, and a CRC code. The data of one data block is stored in a buffer on the memory of the microprocessor, and after checking the CRC code, is written to an electrically erasable non-volatile memory. The size of the memory that can be used differs from the size of the data that can be written to the electrically erasable nonvolatile memory at one time. In the embodiment of the present invention, firmware data is recorded and used in the R to W channels.

FIG. 5 is a diagram showing an audio signal according to an embodiment of the present invention.
It is a video playback device. Reference numeral 501 denotes an audio CD recorded with the rewriting firmware data as digital information in the subcode R to W channel portions, and reference numeral 502 denotes audio in which digital information in the subcode R to W channel portions is reproduced simultaneously with the audio data by an audio CD reproducing operation. A CD reproduction module 503 controls reproduction of the audio reproduction module and reproduced subcodes R to W.
A microprocessor having means for determining whether or not the digital information of the channel section is firmware of the microprocessor;
It is a nonvolatile memory that can be electrically rewritten from the memory.

The operation of the audio / video reproducing apparatus according to the embodiment configured as described above will be described below with reference to the flowcharts of FIGS.

FIG. 6 is a flowchart showing the operation of the microprocessor for processing the data of the subcodes R to W channels reproduced by the audio / video module. In step S601, the microprocessor reads the data of the currently reproduced subcodes R to W channels for one data block into the buffer. Step S602
, It is determined whether the read data of the subcodes R to W channels is firmware to be written to the nonvolatile memory 104, and if not, the change process is terminated. If it is determined that the firmware should be written, an error check is performed on the firmware of one data block read into the buffer in step S603. If it is determined in step S604 that there is a data error, the change process is stopped. If it is determined that there is no data error, the firmware for one data block is written to the nonvolatile memory 504.

FIG. 7 is a flowchart of a processing operation for reading data of the subcodes R to W channels for one data block. In step S701, it is determined whether or not the read data of the subcodes R to W channels is a sync code indicating the head of a data block. If it is not a sync code, the data is invalidated and the read processing ends. If the data matches the sync code, in step S702, the read subcode R to W channel data is stored in the buffer. In step S703, it is determined whether data for one data block has been read into the buffer. If the data for one data block is not stored in the buffer, the process is performed again from step S702. If the data for one data block is stored in the buffer, the read data is validated.

FIG. 8 is a flowchart of a processing operation for performing an error check on data of one data block. In step S801, the CRC of data of one data block stored in the buffer is calculated. Step S8
02, stored at the end of the data block
The CRC code and the calculation result of the CRC are compared. If they match, there is no data error, and if they do not match, there is a data error.

FIG. 9 is a flowchart of a processing operation for writing data of one data block stored in the buffer into an electrically erasable nonvolatile memory. In step S901, the block of the nonvolatile memory to be written is erased. In step S902, it is determined whether data of the size of one data block has been written. When the writing is completed, the data writing process ends. In step S903, data is read from the buffer memory. In step S904, the data read in step S903 is written to the nonvolatile memory.

In this embodiment, the subcodes R to W are used as recording locations for digital information of firmware data for rewriting to an audio CD. However, the audio / video reproduction module can reproduce the data and the microprocessor can read it. If it is information, subcode R ~
It need not be the W channel section. In this embodiment, the digital audio / video recording medium is an audio C
However, the digital audio / video recording medium may be an audio MD.

(Embodiment 2) Hereinafter, a second embodiment of the present invention will be described with reference to the drawings. An image data format of a video CD as a general digital audio / video recording medium will be described with reference to the drawings. The signal format of the video CD described above is shown in FIG.
As shown in the figure, a unit called a sector, which is the minimum unit of information, is formed, and the sector is continuously composed of image information (MPE
G stream). One sector consists of 4 bytes of start byte, SCR (System Clock Reference)
It is composed of a code of 5 bytes, a multiplexing rate of 3 bytes, and packet data of 2312 bytes.

FIG. 11 is a diagram for explaining the format of the first sector of a packet of a digital video disk.
The first packet is a packet including a system header, and the subsequent packet contains image data. FIG.
Indicates the configuration of an image sector including image data, and includes a packet start code of 3 bytes, a stream ID of 1 byte, a packet length of 2 bytes, and a buffer scale size of 2.
Byte, PTS (Presentation Time Stamp) 5 bytes, DTS (Decoding Time Stamp) 5 bytes, and packet data 2294 bytes.

FIG. 5 is a diagram showing an audio signal according to an embodiment of the present invention.
This is a video playback device, which is the same as the first embodiment of the present invention.

The operation of the audio / video reproducing apparatus of the embodiment configured as described above will be described below with reference to the flowchart of FIG.

FIG. 13 is a flowchart of the operation of the microprocessor processing the image data reproduced by the audio / video module. In step S1301, the microprocessor reads the currently reproduced image data for one screen into a buffer. Step S130
2, the image data for one screen is stored in the nonvolatile memory 50.
Write to 4.

By executing the above-described flow, an image to be displayed at a time other than when a video CD is reproduced can be stored in a nonvolatile memory and displayed.

In this embodiment, the digital audio / video recording medium is a video CD, but the digital audio / video recording medium may be a DVD video disk.

[0026]

As described above, the present invention provides an audio / video reproducing module capable of reproducing digital information simultaneously with audio / video data, an electrically erasable nonvolatile memory rewritable by a microprocessor, and an audio / video reproducing module. The digital information is constantly monitored, and when it is determined that the firmware is the microprocessor firmware, a method of writing the digital information to an electrically rewritable nonvolatile memory is provided, so that a hardware which is not originally required for the audio / video reproducing apparatus is provided. An excellent firmware change method for an audio / video playback device that does not require a wear resource and can simplify the trouble of changing the firmware can be realized.

Also, by combining with the image display function, the image displayed on the audio / video playback device can be
The user can freely select from audio and video recording media.

[Brief description of the drawings]

FIG. 1 is a diagram showing a signal format of an audio CD.

FIG. 2 is a diagram showing a format of a subcode of an audio CD.

FIG. 3 is a diagram showing a format of a Q channel of an audio CD.

FIG. 4 is a diagram showing a format of one data block handled by a microprocessor;

FIG. 5 shows an audio / video signal according to the first embodiment of the present invention.
Block diagram of audio / video playback device of firmware update method for video playback device

FIG. 6 is a flowchart for explaining the operation of the first embodiment of FIG. 5;

FIG. 7 is a flowchart illustrating an operation of reading data of one data block in the flow of FIG. 6;

8 is a flowchart for explaining an error check operation of data of one data block in the flow of FIG. 6;

9 is a flowchart illustrating an operation of writing data to a nonvolatile memory in the flow of FIG.

FIG. 10 is a diagram showing a video CD image sector fort.

FIG. 11 is a diagram showing a video CD image head sector format.

FIG. 12 is a diagram showing a video CD image data sector format.

FIG. 13 is a flowchart for explaining the operation of the second embodiment of FIG. 5;

FIG. 14 is a block diagram of an audio / video reproducing apparatus of a conventional audio / video reproducing apparatus with a firmware change method.

[Explanation of symbols]

 501,1401 CD 502 Audio / video playback module 503,1403 Microprocessor 504,1404 Non-volatile memory 505,1409 Image display device 1402 Audio / video playback module 1405 Rewriting interface 1406 Mode switch 1407 Dedicated rewriting device 1408 Rewriting firmware data

Claims (2)

[Claims] 1. An audio / video reproducing apparatus capable of reproducing a digital audio / video recording medium on which a subcode is recorded, wherein a microprocessor for controlling the audio / video reproducing apparatus and firmware of the microprocessor are stored. An electrically rewritable non-volatile memory, means for reading the sub-code reproduced from the audio / video reproducing device by the microprocessor, and the firmware included in the sub-code by the microprocessor. Means for determining whether or not the firmware is read, means for reading only the firmware data inside the subcode by the microprocessor, and means for reading the firmware data by the microprocessor in logical block units. Means for detecting the head of the logical block by the microprocessor, means for increasing the reliability of the firmware by performing an error check on the data of the firmware, and processing of the data of the firmware by the microprocessor. Means for writing to the non-volatile memory, and an audio / video reproducing apparatus and a firmware change method. 2. An audio / video reproducing apparatus capable of reproducing a digital audio / video recording medium on which image information is recorded, wherein a microprocessor for controlling the audio / video reproducing apparatus and firmware of the microprocessor are stored. An electrically rewritable non-volatile memory, means for reading out the image information reproduced from the audio / video reproduction device by the microprocessor, and means for writing the image information in the non-volatile memory by the microprocessor When,
An image display device for displaying the image information stored in the non-volatile memory by the microprocessor.