JP2000078491A - Control program reloading method for digital broadcast reception equipment and digital broadcast reception equipment - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a control program reloading method or the like not to generate a cycle wait caused by division without providing a memory, which is not required for digital broadcast reception equipment excepting for the time of control program reloading. SOLUTION: Concerning the method for reloading a control program, which is used for the digital broadcast reception equipment at present, to a control program transmitted from a broadcasting station, this method is provided with an inhibition step for inhibiting the use of a memory for image decode to an image decoder, a reception step 91 for receiving the control program, storage steps S92, S11 and S12 for storing the control program received in the reception step into the memory for image decode, for which the use is inhibited to the image decoder in the inhibition step, a replacement step S13 for reloading the control program used at present to the control program stored in the memory for image decoding, and a permission step for permitting the use of the memory for image decoding to the image decoder.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for rewriting a control program for a digital broadcast receiving apparatus and a digital broadcast receiving apparatus, and more particularly to a technique for rewriting a currently used control program to a control program transmitted from a broadcasting station. .

[0002]

2. Description of the Related Art At present, MPEG (Moving Picture Image) is used.
In digital broadcasting using a transport stream or the like, images, sounds, and various other data are broadcast.

FIG. 6 is a block diagram showing an outline of a digital broadcast transmitting apparatus of the MPEG2 standard.

[0004] This transmission apparatus digitizes images and sounds for each program, and then encodes and compresses the images and sounds to generate a plurality of encoders 601 for generating image streams and audio streams.
And program specification information (PSI: Program Specific
Information) and program information (SI: Service Informatio)
n) a data generation circuit 602 for generating a data stream from service information, and a transport stream packet multiplexed by time-division multiplexing of the data stream, image streams of a plurality of programs and audio streams. A multiplexing circuit 603 for generating
A modulator 604 for digitally modulating the stream packet to generate a modulated wave that can be transmitted.

[0005] An image stream and an audio stream generated by a plurality of encoders 601 and a data generation circuit 602 are provided.
And the data stream generated by the multiplexing circuit 60
3, a multiplexed MPEG-2 standard transport stream packet is generated, and a modulator 604 digitally modulates the transport stream packet to generate a modulated wave.

[0006] Here, three sets of units for generating a modulated wave in this manner are shown, and each modulator 604 includes:
Modulated waves of different frequencies are generated and transmitted to transmission lines (radio waves, cables, etc.). For example, in the case of digital satellite broadcasting, modulated waves can be simultaneously transmitted by the number of transponders (repeaters) provided in a satellite (not shown), and each modulated wave is transmitted via a transponder corresponding to each modulator 604. Simultaneously transmitted to a plurality of digital broadcast receiving devices.

FIG. 7 is a block diagram schematically showing a digital broadcast receiving apparatus conforming to the MPEG2 standard.

[0008] The receiving apparatus includes a tuner 701 that selectively tunes a modulated wave including a channel specified by a user from a plurality of modulated waves transmitted to a transmission path and receives the modulated wave. A demodulator 702 for digitally demodulating the modulated wave to generate a multiplexed transport stream packet;
A packet separation circuit 703 for separating a stream packet to generate a data stream, an image stream and an audio stream of a plurality of programs, a transport decoder (hereinafter referred to as “TD”) 704 for extracting a target stream, An audio decoder 705 that expands and decodes an audio stream and then converts it into an analog signal to generate an audio signal
And an image decoder 706 for expanding and decoding an image stream to generate image information, and an image decoding memory 708 used by the image decoder 706 as a work area.
A service information storage RAM 707 for storing service information included in the data stream; a CPU 709 for controlling each unit of the receiving apparatus; a flash ROM 710 for storing a control program for the CPU 709;
Main RAM 7 used as work area by U709
11, a screen synthesizing device 712 for synthesizing image information and service information to generate an image signal, and a CPU bus 713 connected between components for transferring data. Here, the CPU bus 713 is connected to the tuner 701.
, A demodulator 702, a TD 704, a CPU 709,
It is connected to a flash ROM 710, a main RAM 711, and a screen synthesizing device 712, and controls the CPU 709,
Alternatively, it is used to transfer data by DMA transfer or the like.

FIG. 7 shows a speaker 714 for converting an audio signal generated by the audio decoder 705 into audio and a monitor 715 for generating an image from an image signal generated by the screen synthesizing device 712, together with the receiving device.

[0010] The modulated wave received by the tuner 701 is
A transport stream packet demodulated and multiplexed by the demodulator 702 is generated, separated into each stream by the packet separation circuit 703, and a target stream is extracted by the TD 704. Here, the extracted audio stream is converted into an audio signal by an audio decoder 705 and converted into audio by a speaker 714, and the extracted image stream is converted into image information by an image decoder 706, and is synthesized with service information by a screen synthesis device 712. Monitor 71
5 displays the image. Here, the service information included in the extracted data stream is temporarily stored in the service information storage RAM 707, and then only the information specified by the user is transferred to the screen synthesizing device 712 via the TD 704 and the image information Is synthesized with

Here, a unit of data transmission of a transport stream packet transmitted from the digital broadcast transmitting apparatus and received by the digital broadcast receiving apparatus is called a packet, and information to be transmitted is generated from what. Regardless, all information is transmitted in this packet. The basic size of this packet is 188 bytes.

A data structure of service information and the like stored in the service information storage RAM 707 is called a section structure, and a group of data of the section structure is called a table.

FIG. 8 is a diagram showing a table of this section structure.

This table has a table ID (table_
id) and the table ID extension (table_id_ext
ention) and a section length (section_length).

The table ID and the table ID extension are used by the TD 704 to retrieve the target table.

Here, the table ID is an identifier indicating the type of the table, and the table ID extension is an extended identifier indicating a more detailed table type for each type indicated by the table ID.

The section length (section_length)
Is an 8-bit (= 1 byte) data byte (data_b
yte), the total amount of data in the section
This is data indicated in byte units.

The control program of the digital broadcast receiving apparatus may need to be changed for reasons such as a change in the service form of the broadcasting station. There are various methods for rewriting the control program being used to a new control program.One of them is to transmit a new control program from a broadcasting station, and a digital broadcast receiving apparatus to receive the control program, There is a method of rewriting a control program used so far to a received control program. This method is convenient for the user because it can be performed relatively easily and in a short time, but requires a rewriting software program and hardware.

FIG. 9 is a diagram showing a transmission form of a control program in the case of digital satellite broadcasting. The control program is transmitted from the broadcast station to the digital broadcast receiving device at the user's home via a satellite, together with image data, audio data, and the like.

A method of rewriting a control program currently used in the digital broadcast receiving apparatus to a control program transmitted from the digital broadcast transmitting apparatus will now be described.

Normally, in a digital broadcast receiving apparatus having a function of rewriting (downloading) a control program, the control program is stored in a rewritable flash ROM.

FIG. 10A is a diagram schematically showing a memory map of the flash ROM 710 holding a control program.

The control program stored in the flash ROM 710 includes a receiving program, a download program, an OS, and a device driver. Here, the flash ROM 710 stores a boot program separately from the control program.

The control program has a data amount of several megabytes and is usually transmitted in a plurality of packets. Therefore, when the digital broadcast receiving apparatus rewrites the control program, the currently used control program cannot be rewritten until all the control programs have been received and processed. Therefore, in order to accumulate a part of the received control program, a memory having a storage capacity enough to store the entire control program is used as the flash ROM 710 for storing the control program.
Other than required. In the digital broadcast transmitting apparatus, the received control program is stored in the main RAM 711.

FIG. 10B is a diagram schematically showing a memory map of the main RAM 711 in which a control program is stored.

The configuration of the control program stored in the main RAM 711 is the same as that of the flash ROM 710. The main RAM 711 is a work area for the CPU 709 at times other than rewriting the control program.

In the digital broadcast transmitting apparatus, a data stream is generated by a data generation circuit 602 from a control program to be transmitted, and a data stream generated from service information is generated.
A modulated wave is generated in the same manner as the stream, and is transmitted to the transmission path.

Under the control of the CPU 709 executing the control program stored in the flash ROM 710, the digital broadcast receiving apparatus receives the modulated wave including the data stream generated from the control program by the tuner 701,・ Stream TD70
4 and store service information RA in section structure
After temporarily storing the control program in M707, the control program is extracted and stored in a free area of the main RAM 711. When all the control programs are stored, the control program stored in the flash ROM 710 is rewritten to the control program stored in the main RAM 711.

The data format of the transmitted control program is usually ARIB (Association of Radio Industry).
ries and Businessesz) Download Control Table (Download Control Table: STD-B16)
Hereinafter, a “DCT” and a download table (hereinafter referred to as “DLT”) are used. Of course, each broadcaster can use its own format individually. DCT and DLT are both types of tables having a section structure.

FIG. 11 is a diagram showing a DCT format.

The DCT has a DCT table ID (tabl
e_id), section length (section_length), transport stream ID (transport_stream_id), download packet ID (DL_PID), model information length (mo
del_info_length) and model information (model_info)
Etc. are included.

The DCT table ID (table_id) is “0x
C0 ".

The transport stream ID (transp
ort_stream_id) is an identifier of the transport stream, and specifies the frequency of the modulated wave to be received by the tuner 701.

Download packet ID (DL_PID)
Is a packet identifier, and specifies a packet to be extracted by the TD 704.

The model information length (model_info_length) is
This is data indicating the total data amount of the model information (model_info) in byte units.

The model information (model_info) includes a maker ID (maker_id) for identifying the maker of the receiving device, a model ID (model_id) for identifying the model of the receiving device,
Version ID that identifies the software version of the receiving device
(Version_id).

FIG. 12 is a diagram showing the format of DLT.

The DLT has a DLT table ID (tabl
e_id), section length (section_length), manufacturer I
D (maker_id), model ID (model_id), version ID (version_id), download software (code_data_byte), and the like.

The DLT table ID (table_id) is “0x
C1 ".

The section length (section_length) is always "0x89C".

Maker ID (maker_id), model ID
(Model_id) and version ID (version_id) are the same as in DCT.

Download software (code_data_
byte) represents the software itself, and its data amount is 8
Bit x 2048 (2K bytes).

For DCT and DLT, refer to “CS Digital Broadcasting Standard Shared Receiver, Standard, ARIB STA
NDARD, ARIB STD-B16 Version 1.0 (Association of Radio Industries and Businesses): pages 12 to 16 ".

The DCT is multiplexed on all modulated waves received by the digital broadcast receiving device.

The digital broadcast receiving apparatus receives any one of the modulated waves and performs filtering of the DCT multiplexed on the modulated wave received by the TD 704 under the control of the CPU 709 which always executes the download program stored in the flash ROM 710. Is performed. Subsequently, the filtered DCT is temporarily stored in the service information storage RAM.
707, and the CPU 709 sets the maker ID (ma
ker_id), a model ID (model_id), and a version ID (version_id), and it is determined whether or not a suitable DLT exists.

When the CPU 709 determines that a suitable DLT exists, the CPU 709 controls the screen synthesizing device 712 to display on the monitor 715 a message for notifying the user that the control program can be changed.

FIG. 13 is a flowchart showing a conventional control program rewriting method.

(1) When the user sees the above message and instructs to change the control program, the tuner 701
Receives the modulated wave identified by the corresponding transport_stream_id in the DCT (step S91).

(2) The demodulator 702 demodulates the received modulated wave, the packet separation circuit 703 separates it, and the TD 704
Performs filtering, and stores the corresponding DLT in the service information storage RAM 707 (step S92).

(3) The CPU 709 stores the DLT download software (code_data_byte) stored in the service information storage RAM 707 in the main RAM 711 (step S93).

(4) The entire control program is transferred to the main RA
It is determined whether the data has been stored in M711. If not all of them are accumulated, the rest is filtered in step S9.
2 and the process is repeated until all data is accumulated (step S9).
4).

(5) After storing the entire control program, the CPU 709 rewrites the control program stored in the flash ROM 710 to the control program stored in the main RAM 711 (step S95).

(6) After rewriting the control program, boot the rewritten control program (step S96).

As described above, in the conventional control program rewriting method, the transmitted control program is temporarily
After the data is stored in the AM 711, the control program stored in the flash ROM 710 is rewritten.

[0055]

In the above prior art,
When rewriting the control program, a main RAM having at least a storage capacity for the data amount of the control program is required. In addition, the storage capacity of the main RAM is reduced to a necessary level other than when the control program is rewritten. Instead, the flash ROM is duplicated, and the control program currently being used is stored on one side and the other is received from a broadcasting station. A method of storing a control program is also possible.

However, other than when the control program is rewritten, neither a main RAM having a storage capacity for the data amount of the control program nor a dual flash ROM is required, and the number of components is increased only for rewriting the control program. It is not desirable that the cost of the apparatus rises.

Further, the storage capacity of the main RAM is suppressed,
There is also a divided download method in which the control program is divided into several parts smaller than the amount of data that can be stored in the main RAM, and rewritten in units of parts.

However, the cycle at which the control program is transmitted is about 8 minutes and 30 seconds. In such a divided download, the period wait increases in proportion to the number of divisions. On the other hand, the processing time is prolonged, which is extremely inconvenient for the user.

Accordingly, the present invention provides a control program rewriting method in which a digital broadcast receiving apparatus does not have a memory which is not required except for rewriting a control program when rewriting a control program, and which does not cause a cycle wait due to division. , A digital broadcast receiving apparatus, and a storage medium storing a control program rewriting method.

[0060]

According to the control program rewriting method of the present invention, when encoded image data obtained by encoding image data is inputted, the code inputted by using an image decoding memory as a work area is used. Decoder for decoding encoded image data, rewritable program memory storing at least a control program for controlling a receiving operation, and executing a control program stored in the program memory for transmission from a broadcasting station A digital broadcast receiving apparatus comprising: a CPU for performing control for receiving a new control program, wherein the digital decoder receives a new control program, and rewrites the control program stored in the program memory to a new control program transmitted from a broadcasting station. Prohibition step for prohibiting the use of the image decoding memory Receiving a new control program transmitted from a broadcasting station under the control of the CPU; and storing the control program received in the receiving step in an image decoding memory in which use of the image decoder is prohibited in the prohibiting step. A rewriting step of rewriting the control program stored in the program memory to a new control program stored in the image decoding memory in the storing step after storing all of the new control program in the storing step. ,
A permission step of permitting the image decoder to use the image decoding memory after rewriting the control program in the rewriting step.

As a result, the control program can be rewritten using the image decoding memory, so that it is not necessary to mount a main memory larger than the data amount of the control program.

Accordingly, there is no need for a memory that is not required except when the control program is rewritten, and there is no need to wait for a period due to division.

[0063]

Embodiments of the present invention will be described below with reference to the drawings.

(Embodiment 1) In a digital broadcast receiving apparatus according to Embodiment 1 of the present invention, when a control program is rewritten, the received control program is not stored in the main RAM, but is stored in the image decoding memory. I do. (Configuration) FIG. 1 is a block diagram schematically showing a digital broadcast receiving apparatus according to Embodiment 1 of the present invention.

Of the components shown in FIG. 1, those denoted by the same reference numerals as the components shown in FIG. 7 have the same functions, and therefore the description thereof will be omitted and only the different components will be described. I do.

Here, it is assumed that the data amount of the control program is 2 megabytes.

The digital broadcast receiving apparatus according to Embodiment 1 of the present invention differs from the digital broadcast receiving apparatus shown in FIG.
M102.

The image decoding memory 101 is the same as the image decoding memory 708 shown in FIG. 7 in that the image decoding memory 101 is used as a work area.
, And is dedicated to the image decoder 706, whereas the image decoding memory 101 is
Not only that, it is also connected to the CPU bus 715, and can transfer data to and from other components connected to the CPU bus 715 when not used for the image decoder 706. In particular, when the control program is rewritten, it is used to store the control program.

Normally, the image decoding memory 101 has a storage capacity of about several megabytes, and here has a storage capacity of 2 megabytes.

It should be noted here that the storage capacity of the image decoding memory 101 must be equal to or larger than the data amount of the control program to be rewritten.

The main RAM 102 is similar to the main RAM 711 shown in FIG. 7 in that it is used as a work area by the CPU 709. However, as shown in FIG. 10B, the main RAM 711 has a storage enough to store all control programs. Main RAM while having capacity
The memory 102 does not have a storage capacity enough to store the entire control program, but has a storage capacity required only when the control program is not rewritten. Thus, the main R
The storage capacity of the AM 711 depends on the data amount of the control program, but the storage capacity of the main RAM 102 does not depend on the data amount of the control program. Therefore, if the data amount of the control program is 2 megabytes, the main RAM 711 has a storage capacity of 2 megabytes or more. Although it is necessary to have a capacity, the main RAM 102 may usually have a storage capacity considerably smaller than 2 megabytes. For example, a storage capacity of 1 megabyte is sufficient for a work area of the CPU 709.

FIG. 2A is a diagram schematically showing a memory map of the flash ROM 710 holding a control program similarly to FIG. 10A. Here, the flash ROM 710 stores a control program of 2 megabytes.

FIG. 2B is a diagram schematically showing a memory map of the main RAM 102.

The main RAM 102 has a storage capacity of 1 megabyte, all of which is a work area of the CPU 709.

FIG. 2C is a diagram schematically showing a memory map of the image decoding memory 101 storing the control program.

The configuration of the control program stored in the image decoding memory 101 is the same as that of the flash ROM 7
As in 10, a control program of 2 megabytes is stored. At the time other than the rewriting of the control program, the image decoding memory 101 stores the image decoder 7.
06 work area. (Operation) The digital broadcast receiving apparatus according to the first embodiment of the present invention controls the modulated wave including the data stream generated from the control program under the control of CPU 709 executing the control program stored in flash ROM 710. When the data stream is received by the tuner 701, the data stream is taken out by the TD 704, and temporarily stored in the service information storage RAM 707 in a section structure, a control program is extracted and stored in the image decoding memory 101, and all control programs are stored. Flash RO
The control program stored in M710 is rewritten to the control program stored in the image decoding memory 101.

The processing operation of the digital broadcast receiving apparatus according to the first embodiment of the present invention from receiving any modulated wave to displaying a message indicating that the control program can be changed is the same as the conventional one. Therefore, the description is omitted.

Normally, an image stream is not multiplexed in a transport stream packet in which data of a control program is transmitted. Further, since the image is not decoded when the control program is rewritten, the image decoder 706 uses the image decoding memory 101 between the time when the user instructs the change of the control program and the time when the processing is completed. Therefore, the CPU or the like can write arbitrary data to the image decoding memory 101 and read arbitrary data from the image decoding memory 101.

FIG. 3 is a flowchart showing a control program rewriting method according to the first embodiment of the present invention.

In each of the steps shown in FIG.
Steps indicated by the same numbers as those in Steps 3 perform the same processing.

(1)-(2) Steps S91-S91 in FIG.
This is the same as S92.

(3) The CPU 709 stores the DLT download software (code_data_byte) stored in the service information storage RAM 707 in the image decoding memory 1.
01 (step S11).

(4) It is determined whether or not the entire control program has been stored in the image decoding memory 101. If not all are accumulated, the process returns to step S92 to filter the rest, and is repeated until all are accumulated (step S12).

(5) After storing the entire control program, the CPU 709 rewrites the control program stored in the flash ROM 710 to the control program stored in the image decoding memory 101 (step S1).
3).

(6) Same as step S96 in FIG.

As described above, in the control program rewriting method according to Embodiment 1 of the present invention, the transmitted control program is temporarily stored in the image decoding memory 101, and then stored in the flash ROM 710. Rewrite as.

(Embodiment 2) In a digital broadcast receiving apparatus according to Embodiment 2 of the present invention, when a control program is rewritten, the received control program is not stored only in the main RAM, but is stored in the main RAM and the image decoder. And store it in both memories. (Configuration) A block diagram schematically showing a digital broadcast receiving apparatus according to the second embodiment of the present invention is the same as that of the first embodiment.

Here, it is assumed that the data amount of the control program is 2 megabytes.

The digital broadcast receiving apparatus according to the second embodiment of the present invention is different from the first embodiment only in the image decoding memory 101 in function.

Image Decoding Memory 10 of Second Embodiment
An image decoding memory 1 according to the first embodiment is different only in that the storage capacity is smaller than the data amount of the control program.
01 is different. Here, the image decoding memory 10
1 has a storage capacity of 1 megabyte.

The main RAM 102 has a storage capacity of 1 megabyte as a work area for the CPU 709.
When the control program is rewritten, it is used to store the control program together with the image decoding memory 101.

It should be noted that the main RAM 102
Is required to be equal to or greater than the data amount of the control program to be rewritten.

FIG. 4A is a diagram schematically showing a memory map of the flash ROM 710 holding a control program similarly to FIG. 10A. Here, the flash ROM 710 stores a control program of 2 megabytes.

FIG. 4B is a diagram schematically showing a memory map of the main RAM 102 storing a part of the control program.

FIG. 4C is a diagram schematically showing a memory map of the image decoding memory 101 storing a part of the control program.

The configuration of the control program divided and stored in the main RAM 102 and the image decoding memory 101 is the same as that of the flash ROM 710, and stores a 2-megabyte control program. At the time other than the rewriting of the control program, the main RAM 102 becomes a work area of the CPU 709,
The image decoding memory 101 includes an image decoder 706.
Work area. (Operation) The digital broadcast receiving apparatus according to the second embodiment of the present invention controls the modulated wave including the data stream generated from the control program under the control of CPU 709 executing the control program stored in flash ROM 710. The data stream received by the tuner 701 is extracted by the TD 704, temporarily stored in the service information storage RAM 707 in a section structure, and then the control program is extracted and stored in the free area of the main RAM 102 and the image decoding memory 101. When all the control programs are stored, the control programs stored in the flash ROM 710 are rewritten to the control programs stored in the free space of the main RAM 102 and the image decoding memory 101.

The processing operation of the digital broadcast receiving apparatus according to the second embodiment of the present invention from receiving any modulated wave to displaying a message indicating that the control program can be changed is the same as the conventional one. Therefore, the description is omitted.

FIG. 5 is a flowchart showing a control program rewriting method according to the second embodiment of the present invention.

Note that, among the steps shown in FIG.
Steps indicated by the same numbers as those in Steps 3 perform the same processing.

(1) to (2) Steps S91 to S91 in FIG.
This is the same as S92.

(3) DLT download software (code_d) stored in the service information storage RAM 707
ata_byte) of data in the main RAM1
02 is determined (step S21).

(4) If it is determined in step S 21 that the service information storage RAM 70
DLT download software (code_data_byte) stored in the main RAM 102 is stored in the main RAM 102 (step S22).

(5) The entire RA is transferred to the main RA
It is determined whether the data has been stored in M102. If not all of them are accumulated, the rest is filtered in step S9.
Returning to step S2, if all the data has been stored, the process goes to step S27 to rewrite the control program (step S23).

(6) If it is determined that the processing is not step S21, the CPU 709 sets the service information storage RAM 70
The DLT download software (code_data_byte) stored in the memory 7 is stored in the image decoding memory 101 (step S24).

(7) The entire control program is transferred to the main RA
It is determined whether or not the data has been stored in M102 and the image decoding memory 101. If not all the data has been stored, the process goes to step S26 to filter the remaining data.
Go to (Step S25).

(8) Same as step S92 in FIG.

(9) When the entire control program is stored, the CPU 709 rewrites the control program stored in the flash ROM 710 to the control program stored in the main RAM 102 and the image decoding memory 101 (step S27).

(10) This is the same as step S96 in FIG.

As described above, in the control program rewriting method according to the second embodiment of the present invention, the transmitted control program is temporarily stored in main RAM 102 and image decoding memory 101, and then stored in flash ROM 710. Rewrite with the control program that is running.

In the second embodiment, the received control program is first stored in the main RAM, and then the remaining control program is stored in the image decoding memory. However, the control program may be stored first. Alternatively, after the image data is first stored in the image decoding memory, the portion that cannot be stored may be stored in the main RAM.

Further, not all of the control programs are necessarily updated at the same time, and only a part of the control program may be transmitted, or the user may select to rewrite only a part. For example, when only the device driver is rewritten, the device driver which is a part of the transmitted control program is stored in one of the main RAM and the image decoding memory.

Here, it is assumed that the total of the storage capacity of the main RAM 102 and the storage capacity of the image decoding memory must be equal to or larger than the data amount of the control program to be rewritten. The control is not limited to the main RAM and the image decoding memory. If the total of the main RAM, the image decoding memory, and the other storage areas is equal to or larger than the data amount of the control program to be rewritten, The entire program can be divided and stored in each storage area. For example, the other storage area that can be stored may be a storage area other than the storage area of the flash ROM in which the currently used program is stored. In other words, flash ROM and main RAM
Is smaller than the sum of the data amount of the control program to be rewritten and the data amount of the currently used program, the storage capacity of the image decoding memory is determined by the insufficient storage capacity. All that is required is the above.

Before the storage of the control program is started, information indicating the data amount of the control program to be received is received from the broadcasting station, and the storage area of the data amount indicated by the information is stored in the image decoding memory or the main RAM. It is also possible to determine whether or not the image data is stored in either one of the image decoding memory and the main RAM. It may be stored in both the storage memory and the main RAM. For example, each section of the DLT has an extension section number (Lsection
_number) and the last extended section number (last_Lsection_number) which is the number of the last section (that is, the section having the largest section number). Therefore, since the product of the final extension section number and the data amount of the download software (code_data_byte) is the data amount of the control program to be rewritten, any one of the sections of the DLT is included before the storage of the control program is started. The data amount of the control program to be rewritten can be known from the last extension section number.

[0114]

(1) In the control program rewriting method according to the present invention, when coded image data obtained by coding image data is input, the coding program input using a memory for image decoding as a work area. An image decoder for decoding image data, a rewritable program memory storing at least a control program for controlling a receiving operation, and a control program stored in the program memory for executing the control program and transmitted from a broadcasting station. A digital broadcast receiving apparatus comprising: a CPU for performing a control for receiving the new control program; and a control program for rewriting a control program stored in the program memory to a new control program transmitted from a broadcasting station. A prohibition step of prohibiting use of the image decoding memory. A receiving step of receiving a new control program transmitted from the broadcasting station under the control of the CPU; and a storing step of storing the control program received in the receiving step in an image decoding memory in which use of the control program is prohibited in the image decoder in a prohibiting step. A rewriting step of rewriting the control program stored in the program memory to a new control program stored in the image decoding memory in the storing step after storing all of the new control program in the storing step; And a permission step of permitting the image decoder to use the image decoding memory after rewriting the control program.

As a result, since the control program can be rewritten using the image decoding memory, it is not necessary to mount a main memory larger than the data amount of the control program.

Therefore, there is no memory that is not required except for rewriting the control program, and there is no periodical waiting due to division.

(2) In the control program rewriting method according to the present invention, when coded image data obtained by coding image data is input, the coded image data input using a memory for image decoding as a work area. An image decoder for decoding a program, a rewritable program memory storing at least a control program for controlling a receiving operation, and a new program transmitted from a broadcasting station by executing the control program stored in the program memory. A digital broadcast receiving apparatus including a CPU for performing control for receiving a control program and a main memory used by the CPU as a work area rewrites a control program stored in the program memory to a new control program transmitted from a broadcast station. A method comprising the steps of: A prohibition step of prohibiting the use of the memory for over de, a receiving step of receiving the new control program transmitted from a broadcasting station under the control of the CPU,
The control program received in the receiving step may be the main memory, an image decoding memory whose use is prohibited for the image decoder in the prohibition step, or an image whose use is prohibited for the image decoder in the main memory and the prohibition step. An accumulating step of accumulating in both the decoding memory, and a rewriting step of rewriting the control program stored in the program memory into a new control program accumulated in the accumulating step after accumulating all of the new control program in the accumulating step And a permission step of permitting the image decoder to use the image decoding memory after rewriting the control program in the rewriting step.

As a result, since the control program can be rewritten using the main memory and the image decoding memory, it is not necessary to mount the main memory and the image decoding memory which are larger than the data amount of the control program.

Therefore, there is no memory that is not required except when the control program is rewritten, and there is no periodical waiting due to division.

(3) In the digital broadcast receiving apparatus according to the present invention, when coded image data obtained by coding image data is input, the coded image data input using a memory for image decoding as a work area. An image decoder that decodes the image data, prohibiting means for prohibiting the use of the image decoding memory for the image decoder, and any data stored in the image decoding memory while the prohibiting means prohibits the use of the image decoding memory. And read means for reading arbitrary data from the image decoding memory, and permission means for permitting the image decoder to use the image decoding memory.

As a result, the image decoding memory can be used while the use of the image decoding memory by the image decoder is prohibited, so that the memory resources can be more effectively utilized. (4) A digital broadcast receiving apparatus according to the present invention is a digital broadcast receiving apparatus that rewrites a currently used control program with a new control program transmitted from a broadcasting station, and includes encoded image data obtained by encoding image data. And an image decoder for decoding the encoded image data input using a memory for image decoding as a work area, and a rewritable program storing at least a control program for controlling a receiving operation. A memory, a CPU that executes a control program stored in the program memory and performs control to receive a new control program transmitted from a broadcasting station, and issues a user or broadcast instruction to rewrite a control program currently used. Receiving means for receiving from the station and instructions for rewriting the control program by the receiving means; And inhibiting means for inhibiting the use of the memory for the image decoding respect only put the image decoder,
Receiving means for receiving a new control program transmitted from the broadcasting station under the control of the CPU; and storing means for storing the control program received by the receiving means in an image decoding memory in which use of the control program by the prohibiting means is prohibited by the image decoder. ,
Rewriting means for rewriting the control program stored in the program memory to the control program stored in the image decoding memory by the storage means after the storage means stores all of the new control program, and rewriting means rewriting the control program Permission means for permitting the image decoder to use the image decoding memory after the image decoding.

As a result, the same effect as (1) can be obtained.

(5) A digital broadcast receiving apparatus according to the present invention is a digital broadcast receiving apparatus for rewriting a currently used control program with a new control program transmitted from a broadcasting station, and is a code for encoding image data. When the encoded image data is input, an image decoder that decodes the input encoded image data by using an image decoding memory as a work area, and a rewritable program that stores at least a control program that controls a receiving operation A program memory, a CPU for executing a control program stored in the program memory and performing control to receive a new control program transmitted from a broadcast station,
U, a main memory used as a work area, receiving means for receiving an instruction for rewriting a control program currently used from a user or a broadcasting station, and an image decoder for receiving the instruction for rewriting the control program. Prohibiting means for prohibiting the use of the image decoding memory, receiving means for receiving a new control program transmitted from the broadcasting station under the control of the CPU, and a control program received by the receiving means in the main memory. Storage means for storing both in the image decoding memory whose use has been prohibited for the image decoding memory, or in both the main memory and the image decoding memory whose use has been prohibited by the image decoder by the prohibition means, and the storage means has a new control program. Control program stored in the program memory after Rewriting means for rewriting the RAM to a new control program stored in the storage means, and permission means for permitting the image decoder to use the image decoding memory after the rewriting means rewrites the control program. .

As a result, the same effect as (2) can be obtained.

(6) In (5), the receiving means receives all of the new control program by sequentially receiving a part of the control program divided into a predetermined data amount, and the storage means: Until the main memory determines whether or not there is an empty area of the predetermined data amount, the receiving unit determines that the receiving unit receives a part of the new control program, and the determining unit determines that the receiving unit has the free space. A first storing means for storing a part of the new control program received by the receiving means in the main memory each time; and a receiving means receiving a part of the new control program each time the receiving means determines that it is not the determining means. A second storage unit for storing a part of the control program in an image decoding memory in which the use of the image decoder is prohibited by the prohibition unit. It can also be.

As a result, the control program can be rewritten using the main memory or the main memory and the image decoding memory. Therefore, it is not necessary to mount the main memory and the image decoding memory which are larger than the data amount of the control program. It will be good.

(7) In (5), the receiving means receives all of the new control program by sequentially receiving a part of the control program divided into a predetermined amount of data, and the storage means: The receiving means receives a part of the new control program until the prohibiting means determines whether or not there is a free area of the predetermined data amount in the image decoding memory for which use of the image decoder is prohibited. And a part of the new control program received by the receiving means each time the determining means determines that there is the judgment means, and stores the part of the new control program in the image decoding memory in which the use of the image decoder is prohibited by the prohibition means. After the first storage means and the determination means have determined that the new control program has not been received, each time the reception means receives a part of the new control program, a part of the new control program is stored in the main program. It may be characterized in that it comprises a second storage means for storing in the memory.

As a result, the control program can be rewritten using the image decoding memory or the main memory and the image decoding memory. Therefore, the main memory and the image decoding memory having the data amount of the control program or more can be implemented. You don't have to.

(8) In (5), the receiving means further receives, from a broadcasting station, data amount information indicating the data amount of a new control program to be received, and the storage means further comprises: Determining means for determining whether or not a storage area of the data amount indicated by the obtained data amount information exists in the main memory; and storing the control program received by the receiving means in the main memory when determining that the storage area has the data amount. A first storage unit for storing the control program received by the receiving unit when it is determined that there is no determination unit in the main memory and an image decoding memory in which the use of the image decoder is prohibited by the prohibition unit. Second
And a storage unit.

(9) In (5), the receiving means further receives data amount information indicating a data amount of a new control program to be received from a broadcasting station, and the storage means further comprises: A determination unit that determines whether the storage area of the data amount indicated by the obtained data amount information is in the image decoding memory in which the use of the prohibition unit is prohibited by the image decoder; and A first storage unit for storing the control program received by the receiving unit in an image decoding memory in which the use of the control unit is prohibited by the prohibiting unit; Second storage means for storing, in the main memory, the image decoding memory in which the use of the control program by the prohibition means is prohibited by the image decoder. It may be characterized in that it comprises a.

Thus, since the data amount of the control program can be known before the storage of the control program is started, it is possible to determine in advance where to store the control program.

Therefore, planned control with few failures can be performed, and the processing time and the like can be known in advance.

(10) Further, in (3) to (9),
The prohibiting means prohibits the use of the image decoding memory by prohibiting the input of the encoded image data to the image decoder, and the permitting means inputs the encoded image data to the image decoder. The use of the image decoding memory is permitted by permitting the image decoding.

As a result, the use of the image decoding memory can be prohibited and allowed for the image decoder without adding any special hardware.

(11) A digital broadcast receiving apparatus according to the present invention is a digital broadcast receiving apparatus for rewriting a currently used control program with a new control program transmitted from a broadcasting station. Rewritable program memory for storing a program memory, a main memory used as a work area by a CPU executing a control program stored in the program memory, and an image for decoding encoded image data obtained by encoding image data. An image decoding memory used as a work area of a decoder, wherein the storage capacity of the program memory is smaller than the sum of the data amount of the new control program to be rewritten and the data amount of the control program currently being used. The storage capacity of the main memory should be rewritten Less than the data amount of the control program correct, characterized in that at least the data amount of the new control program storage capacity to are rewritten to the memory for image decoding.

As a result, the same effect as (1) can be obtained.

(12) A digital broadcast receiving apparatus according to the present invention is a digital broadcast receiving apparatus for rewriting a currently used control program with a new control program transmitted from a broadcasting station. Rewritable program memory for storing a program memory, a main memory used as a work area by a CPU executing a control program stored in the program memory, and an image for decoding encoded image data obtained by encoding image data. An image decoding memory used as a work area of a decoder, wherein the storage capacity of the main memory is smaller than the data amount of the new control program to be rewritten, and the storage capacity of the program memory and the storage capacity of the main memory are different. The total is the data of the currently used control program. Only shortfall X than the sum of the data amount of the new control program to be rewritten to the amount less storage capacity of the memory for image decoding shortfall X
It is characterized by the above.

As a result, the same effect as (2) can be obtained.

(13) In the recording medium on which the control program rewriting method according to the present invention is recorded, when the encoded image data obtained by encoding the image data is input, the input is performed using the image decoding memory as a work area. An image decoder for decoding the encoded image data, a rewritable program memory for storing at least a control program for controlling a receiving operation, and a broadcast station for executing the control program stored in the program memory C that controls to receive the new control program sent from C
A digital broadcast receiving apparatus comprising a PU and a computer-readable recording medium recording a control program rewriting program for rewriting a control program stored in the program memory to a new control program transmitted from a broadcasting station, A step of prohibiting the CPU from using the image decoding memory for the image decoder, a step of receiving a new control program transmitted from a broadcasting station, and a step of prohibiting the control program received in the receiving step. Accumulating the image in a memory for image decoding whose use is prohibited in the image decoder in the step; and accumulating the control program stored in the memory for the program after accumulating all the new control programs in the accumulating step. For decoding the image A control program rewriting for controlling a rewriting step of rewriting a new control program stored in the memory and a permission step of permitting the image decoder to use the image decoding memory after rewriting the control program in the rewriting step. Record the program.

As a result, the same effect as (1) can be obtained.

(14) In the recording medium in which the control program rewriting method according to the present invention is recorded, when the encoded image data obtained by encoding the image data is input, the input is performed using the image decoding memory as a work area. An image decoder for decoding the encoded image data, a rewritable program memory for storing at least a control program for controlling a receiving operation, and a broadcast station for executing the control program stored in the program memory C that controls to receive the new control program sent from C
A digital broadcast receiving device comprising a PU and a main memory used by the CPU as a work area, executes a control program rewriting program for rewriting a control program stored in the program memory to a new control program transmitted from a broadcasting station. A computer-readable recording medium having recorded thereon, wherein the CPU has a step of prohibiting the image decoder from using the image decoding memory, and a step of receiving a new control program transmitted from a broadcasting station. The use of the control program received in the receiving step in the main memory, the image decoding memory in which the use of the control program is prohibited in the image decoder in the prohibition step, or the use of the control program in the main memory and the image decoder in the prohibition step is prohibited. Image decoding An accumulation step of accumulating the data in both of the memory and a rewriting step of rewriting the control program stored in the program memory into a new control program accumulated in the accumulation step after accumulating all of the new control program in the accumulation step; After the control program is rewritten in the rewriting step, a control program rewriting program for controlling the image decoder to control the permission step of permitting the use of the image decoding memory is recorded.

As a result, the same effect as (2) can be obtained.

[Brief description of the drawings]

FIG. 1 is a block diagram schematically showing a digital broadcast receiving apparatus according to Embodiment 1 of the present invention.

FIG. 2A is a diagram schematically showing a memory map of the flash ROM 710 holding a control program as in FIG. 10A. FIG. 2B is a diagram schematically showing a memory map of the main RAM 102. FIG. 2C is a diagram schematically showing a memory map of the image decoding memory 101 storing a control program.

FIG. 3 is a diagram showing a flowchart of a control program rewriting method according to the first embodiment of the present invention.

FIG. 4A is a diagram schematically showing a memory map of the flash ROM 710 holding a control program similarly to FIG. 10A. FIG. 4B is a diagram schematically showing a memory map of the main RAM 102 storing a part of the control program. FIG. 4C is a diagram schematically showing a memory map of the image decoding memory 101 storing a part of the control program.

FIG. 5 is a diagram showing a flowchart of a control program rewriting method according to Embodiment 2 of the present invention.

FIG. 6 is a block diagram showing an outline of a digital broadcast transmission device of the MPEG2 standard.

FIG. 7 is a block diagram showing an outline of a digital broadcast receiving apparatus of the MPEG2 standard.

FIG. 8 is a diagram showing a table of a section structure.

FIG. 9 is a diagram illustrating a transmission form of a control program in the case of digital satellite broadcasting.

FIG. 10A is a diagram schematically showing a memory map of the flash ROM 710 holding a control program. FIG. 10B is a diagram schematically showing a memory map of the main RAM 711 in which a control program is stored.

FIG. 11 is a diagram showing a DCT format.

FIG. 12 is a diagram illustrating a format of a DLT.

FIG. 13 is a diagram showing a flowchart of a conventional control program rewriting method.

[Description of Signs] 101 Image decoding memory 102 Main RAM 701 Tuner 702 Demodulator 703 Packet separation circuit 704 Transport decoder 705 Audio decoder 706 Image decoder 707 Service information storage RAM 709 CPU 710 Flash ROM 712 Screen combining device 713 CPU bus 714 Speaker 715 Monitor

Continued on the front page F-term (reference) 5C025 BA27 DA01 DA05 5C063 AB03 AC10 DA07 DA13 DB10

Claims (14)

[Claims] 1. An image decoder for decoding an input encoded image data by using an image decoding memory as a work area when the encoded image data obtained by encoding the image data is input, A rewritable program memory storing a control program for controlling a receiving operation, and a CPU for executing a control program stored in the program memory and controlling to receive a new control program transmitted from a broadcasting station Wherein the digital broadcast receiving apparatus rewrites a control program stored in the program memory with a new control program transmitted from a broadcasting station, wherein the image decoder uses the image decoding memory for the image decoder. And a prohibition step of prohibiting transmission from a broadcasting station under the control of the CPU. A receiving step of receiving a new control program; a storing step of storing the control program received in the receiving step in an image decoding memory for which use to the image decoder is prohibited in a prohibiting step; After storing the entirety, after rewriting the control program stored in the program memory to a new control program stored in the image decoding memory in the storing step, after rewriting the control program in the rewriting step A permission step of permitting the image decoder to use the image decoding memory. 2. An image decoder for decoding an input encoded image data by using an image decoding memory as a work area when encoded image data obtained by encoding the image data is input, A rewritable program memory storing a control program for controlling a receiving operation, and a CPU for executing a control program stored in the program memory and controlling to receive a new control program transmitted from a broadcasting station And CP
A digital broadcast receiving apparatus comprising: a main memory used by U as a work area; a method of rewriting a control program stored in the program memory to a new control program transmitted from a broadcasting station; A prohibition step of prohibiting the use of the image decoding memory, a reception step of receiving a new control program transmitted from a broadcasting station under the control of the CPU, and a control program received in the reception step. An accumulating step of accumulating in the image decoding memory whose use is prohibited in the image decoder in the prohibiting step, or in both the main memory and the image decoding memory in which use of the image decoder is prohibited in the prohibiting step; All of the new control programs in steps After rewriting, the control program stored in the program memory is rewritten to a new control program stored in the storing step. The rewriting step rewrites the control program in the rewriting step. A permission step of permitting use of the image decoding memory. 3. When an encoded image data obtained by encoding image data is inputted, an image decoder for decoding the inputted encoded image data by using an image decoding memory as a work area; Prohibiting means for prohibiting the use of the image decoding memory for the decoder; and while the prohibiting means prohibits the use of the image decoding memory, writing arbitrary data to the image decoding memory, A digital broadcast receiving apparatus comprising: control means for reading arbitrary data; and permission means for permitting an image decoder to use an image decoding memory. 4. A digital broadcast receiving apparatus for rewriting a currently used control program with a new control program transmitted from a broadcasting station, wherein when coded image data obtained by coding image data is input, an image is displayed. An image decoder for decoding the input encoded image data using a decoding memory as a work area; a rewritable program memory storing at least a control program for controlling a receiving operation; A CPU that executes a control program stored in the memory and performs control to receive a new control program transmitted from the broadcast station; and an instruction to rewrite a control program currently used.
Receiving means for receiving from a user or a broadcasting station, prohibiting means for prohibiting an image decoder from using the image decoding memory when the receiving means receives an instruction to rewrite the control program, and transmitting from the broadcasting station under control of the CPU. Receiving means for receiving the received new control program, storing means for storing the control program received by the receiving means in an image decoding memory for which use of the image decoder is prohibited by the prohibiting means, and storing means for storing the new control program. Rewriting means for rewriting the control program stored in the program memory to the control program stored in the image decoding memory by the storage means after the entirety of the control program is stored, and rewriting the control program by the rewriting means. Permission means for permitting the decoder to use the image decoding memory; Digital broadcast receiving apparatus, characterized in that it comprises. 5. A digital broadcast receiving apparatus for rewriting a currently used control program with a new control program transmitted from a broadcasting station, wherein when coded image data obtained by coding image data is input, an image is displayed. An image decoder for decoding the input encoded image data using a decoding memory as a work area; a rewritable program memory storing at least a control program for controlling a receiving operation; A CPU that executes a control program stored in the memory and performs control to receive a new control program transmitted from a broadcast station; a main memory used by the CPU as a work area; and a control program currently used. Instructions
Receiving means for receiving from the user or the broadcasting station, prohibiting means for prohibiting the use of the image decoding memory for the image decoder when the receiving means receives an instruction to rewrite the control program, and transmitting from the broadcasting station under the control of the CPU. Receiving means for receiving the new control program, and a control program received by the receiving means,
A storage means for storing in the image decoding memory whose use is prohibited by the prohibiting means for the image decoder, or both a main memory and an image decoding memory whose use is prohibited by the prohibition means for the image decoder; Rewriting means for rewriting the control program stored in the program memory to a new control program stored in the storage means after storing all of the new control program; and an image decoder for rewriting the control program by the rewriting means. And a permission unit for permitting use of the image decoding memory for the digital broadcast receiving apparatus. 6. The receiving means receives all of the new control program by sequentially receiving a part of the control program divided into a predetermined amount of data, and the storage means stores the new control program in the main memory in the main memory. Until it is determined that there is a free area with a data amount of, the receiving means determines each time a part of the new control program is received. A first storage unit for storing a part of the new control program received by the unit in the main memory; and, after determining that the new control program is not the determining unit, each time the receiving unit receives a part of the new control program, the control unit executes the control. 6. The image forming apparatus according to claim 5, further comprising: a second storage unit that stores a part of the program in an image decoding memory in which the use of the image decoder is prohibited by the prohibition unit. The placing of the digital broadcast receiver. 7. The receiving means receives all of the new control program by sequentially receiving a part of the control program divided into a predetermined data amount, and the storage means comprises: The determination is made every time the receiving unit receives a part of the new control program until it is determined whether or not there is a free area of the predetermined data amount in the image decoding memory whose use is prohibited for the decoder. A first storing unit that stores a part of the new control program received by the receiving unit in the image decoding memory in which the use of the image decoder is prohibited by the prohibition unit every time the determination unit determines that there is the determination unit; Means, and when the receiving means receives a part of the new control program, a part of the control program is transferred to the main memory each time the receiving means receives the part. Digital broadcast receiving apparatus according to claim 5, characterized in that it comprises a second storage means for storing. 8. The receiving means further receives, from a broadcasting station, data amount information indicating a data amount of a new control program to be received, and the storage means stores data indicated by the data amount information received by the receiving means. Determining means for determining whether an amount of storage area is present in the main memory; and first storing the control program received by the receiving means in the main memory when determining that the storage area is present in the main memory. Means for storing the control program received by the receiving means in the main memory and the image decoding memory in which the use of the image decoder is prohibited by the prohibiting means when it is determined that there is no determining means. The digital broadcast receiving apparatus according to claim 5, further comprising two storage units. 9. The receiving means further receives data amount information indicating a data amount of a new control program to be received from a broadcasting station, and the storage means stores data indicated by the data amount information received by the receiving means. Determining means for determining whether or not the storage area of the amount is present in the image decoding memory in which the use of the image decoder is prohibited by the prohibiting means; and A first storage unit for storing the control program in the image decoding memory in which the use of the image decoder is prohibited by the prohibition unit; and a control program received by the reception unit when it is determined that there is no determination unit. And a second storage means for storing in the main memory the image decoding memory in which the use of the image decoder is prohibited by the prohibition means. Digital broadcast receiving apparatus according to claim 5, characterized. 10. The prohibition unit prohibits the use of the image decoding memory by prohibiting the image decoder from inputting the encoded image data, and the permission unit controls the image decoder. 10. The digital broadcast receiving apparatus according to claim 3, wherein use of the image decoding memory is permitted by permitting input of the encoded image data. 11. The control program currently used is
A digital broadcast receiving apparatus that rewrites a new control program transmitted from a broadcast station, wherein the rewritable program memory stores a currently used control program, and the control program stored in the program memory is executed. The CPU includes a main memory used as a work area, and an image decoding memory used as a work area of an image decoder for decoding encoded image data obtained by encoding image data. Less than the sum of the data amount of the new control program to be rewritten and the data amount of the currently used control program, the storage capacity of the main memory is less than the data amount of the new control program to be rewritten, The storage capacity of the image decoding memory is Digital broadcast receiving apparatus, wherein the to be modified can be more data amount of the new control program. 12. The control program currently used is
A digital broadcast receiving apparatus that rewrites a new control program transmitted from a broadcast station, wherein the rewritable program memory stores a currently used control program, and the control program stored in the program memory is executed. The CPU comprises: a main memory used as a work area; and an image decoding memory used as a work area of an image decoder for decoding coded image data obtained by encoding image data. The data amount of the new control program to be rewritten is smaller than the data amount of the control program that is currently used, and the sum of the storage capacity of the program memory and the storage capacity of the main memory is smaller than the data amount of the currently used control program. Shortfall than the sum of the amount of data Only small, the storage capacity of the memory for image decoding, digital broadcast receiving apparatus, characterized in that it is shortage X above. 13. An image decoder for decoding an input encoded image data by using an image decoding memory as a work area when the encoded image data obtained by encoding the image data is input; A rewritable program memory storing a control program for controlling a receiving operation, and a CPU for executing a control program stored in the program memory and controlling to receive a new control program transmitted from a broadcasting station A digital broadcast receiving apparatus comprising: a computer readable recording medium storing a control program rewriting program for rewriting a control program stored in the program memory to a new control program transmitted from a broadcasting station. Before the CPU and the image decoder. A prohibition step of prohibiting use of the image decoding memory; a reception step of receiving a new control program transmitted from the broadcast station; and a prohibition step of prohibiting use of the control program received in the reception step for the image decoder. A storage step of storing the new control program in the image decoding memory, and storing the control program stored in the program memory in the image decoding memory in the storage step. Recording a control program rewriting program for controlling a rewriting step of rewriting the control program in the rewriting step, and a permission step of permitting the image decoder to use the image decoding memory after rewriting the control program in the rewriting step. Computer reading Recording medium that can be taken. 14. When an encoded image data obtained by encoding the image data is input, an image decoder that decodes the input encoded image data by using an image decoding memory as a work area; A rewritable program memory storing a control program for controlling a receiving operation, and a CPU for executing a control program stored in the program memory and controlling to receive a new control program transmitted from a broadcasting station And C
A digital broadcast receiving apparatus including a main memory used by the PU as a work area records a control program rewriting program for rewriting a control program stored in the program memory to a new control program transmitted from a broadcasting station. A computer-readable recording medium, the CPU comprising: a prohibition step of prohibiting the image decoder from using the image decoding memory; and a reception step of receiving a new control program transmitted from a broadcasting station. The use of the control program received in the receiving step in the main memory, the image decoding memory in which the use of the image decoder is prohibited in the prohibition step, or the use of the control program in the main memory and the image decoder in the prohibition step is prohibited. Image decoding memo And a rewriting step of rewriting the control program stored in the program memory into the new control program stored in the storing step after storing all of the new control program in the storing step. And a permission step of permitting the image decoder to use the image decoding memory after rewriting the control program in the rewriting step. A computer-readable recording medium recording a control program rewriting program for controlling the image decoder.