JP2002135270A - Data asynchronous transfer system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To asynchronously transfer 1394 packets by utilizing an existing large capacity storage circuit, without newly adding a storage circuit, such as a buffer. SOLUTION: In a data transfer system prepared for video or voice equipment and provided with a recording means for recording data in a recording medium 108, a data storage means 102 to be used at the time of real time recording or real-time reproduction of data in/from the recording medium, and an asynchronous transfer means; an asynchronous transfer area 105 is formed in the data storage means 102, the asynchronous transfer means writes received data in the recording medium 108 via the area 105 at the time of receiving data in the asynchronous transfer, and reads out transmitting data from the recording medium 108 via the area 105 at the time of transmitting the data in the asynchronous transfer. In addition, the system can change the area 105 in the means 102 at any time.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION Field of the Invention The present invention relates to a device for transmitting and receiving data between two or more devices, and more particularly to a device for transmitting and receiving digital data such as a still image, which divides data into a plurality of packets on a communication path and transfers the packets. Belongs to.

[0002]

2. Description of the Related Art In recent years, a mechanism for transmitting and receiving data between various devices using a serial data transfer protocol called IEEE 1394 has been developed. For example, one of the protocols for realizing file transfer by asynchronous communication
One is 1394TA (Trade Associate)
Dion) established by a standardization organization called “tion”
ct Print Protocol (hereinafter, referred to as DPP). Using the DPP, a still image file transfer and printing can be performed by directly connecting devices such as a digital camera and a printer without using a personal computer.

Here, a data transfer method in the DPP will be briefly described with reference to FIGS. 4, 5 and 6. FIG. FIG. 4 shows D
FIG. 5 is a schematic diagram of the PP and IEEE1394, FIG. 5 is a connection diagram of two digital cameras, and FIG. 6 is DPP and IEEE1.
394 is a schematic operation model (for file transfer).

In FIG. 4, the upper part shows the upper layer, and the lower part shows the lower layer. 403 is the DPP, 409 is an application layer, 401 is a command set layer for managing various command sets, 402 is a Thin protocol layer for managing a data transfer protocol, and 404 is a FTC (File) which is a command set for file transfer. Tran
sfer Command set) 405 is a DPC (Dir) which is a command set for connecting to a printer.
ect Print Command set), and the Thin protocol layer 402 is a Thin session layer 40 for dividing and reorganizing application data.
6 and a Thin transaction layer 407 for managing data transmission and reception between the 1394 transaction layer 408
And is divided into

FIG. 5 is a diagram in which the digital camera 500 and the digital camera 501 are connected by a 1394 cable. For example, a still image may be transferred from the digital camera 500 to the digital camera 501 by DPP.
At that time, the digital camera 500 on the transmitting side transmits still image data to the digital camera 501 on the receiving side by a “PUT” command or the like.

FIG. 6 shows a flow of data division at the time of data transmission in the digital camera 500. In the Thin session layer 406, the application data 600
gment Data Unit (hereinafter, referred to as SDU) is divided into segment data 601 and transferred (divided into n [an integer of 1 or more]) in FIG.
In the hin transaction layer 407, the SDU is further divided into 1394 transfer sizes (in FIG. 6, divided into m [an integer of 1 or more]) and transmitted as 1394 packets 602.

[0007] That is, in the transfer in the DPP, application data is divided into SDU units and further divided into 139 units.
It is necessary to divide the packet into four packets. However, in FIG. 6, the addition of header information is omitted to make the flow of data division easier to understand.

FIG. 7 shows a change in data when the digital camera 501 receives a 1394 packet transmitted from the digital camera 500, and FIG.
, The header information omitted is shown.

Reference numeral 700 denotes a transmission-side node, that is, the digital camera 500. Reference numeral 701 denotes a 1394 packet which is a transfer unit when passing through a 1394 cable, for example, 512 bytes; 702, an SDU which is a transfer unit in the Thin protocol 402; Session header indicating the contents of each SDU, size is fixed at 16 bytes, 704 is SDU
706 is application data composed of file data and an FTC command, 707 is an application header added by the Thin session layer 406 and has a fixed size of 24 bytes, 705 is application data 706 and application header 707 The transfer data is composed of

Here, the application data 706 is composed of a plurality of attributes according to the format of the FTC which is a command set for file transfer. Each attribute has an attribute name 800, an attribute length 801, an attribute type 802, an extension flag 803, and an attribute value 8 as shown in FIG.
It consists of 04.

The attribute names include "CMD0",
There are several such as “FIL0” and “DIR0”, and “C
“MD0” represents a command code, “FIL0” is used to represent a file name, and “DIR0” is used to represent a directory name. Further, the command code “CMD0” includes
Several commands are provided, such as "PU
T "and" GET ".

FIG. 9 shows an example of application data when a file is transferred by the "PUT" command.
“CMD0” is inserted in the attribute name 900, and “PUT” is inserted in the attribute value 904. The attribute length 90 is omitted because it is not directly related to the present invention.
1, the attribute type 902, the extension flag 903, and the file data 905 corresponding to the actual file contents.

The application header 707 is an application data length, a destination machine ID (a connection destination ID determined at the time of cable connection).
The session header 702 added in units of SDUs includes a segment length, a segment number, and the like, and represents the contents of the SDU.

Therefore, when the 1394 packet transmitted from the digital camera 500 is received by the digital camera 501, the digital camera 501 needs to combine the received 1394 packet in SDU units and then generate it as application data. Therefore, the digital camera 501 needs to analyze the header added to each data.

Therefore, the receiving side needs a hardware configuration or a software configuration for analyzing the header, and at least S
A buffer having a capacity equal to or larger than the DU size and having a capacity as large as possible is required. Similarly, the transmitting side requires a hardware configuration or a software configuration for adding a header, and requires a buffer having the above-described capacity.

In IEEE 1394, in order to perform data transfer, the CS defined by IEEE 1212 is used.
R (Control and Status Regi)
(register architecture). In the Thin protocol 402, as shown in FIG. 13, there are provided three areas: a Connection register used for establishing a connection, an SDU register used for data transfer, and an SDU management register used for controlling data transfer, and the Connection register is directly connected to the present invention. The description is omitted because it is not relevant. S
The DU register determines its size at connection time and
In the n protocol, each process is performed for each size, and SDU
The management register is fixed at 4 bytes.
A command for controlling transfer for each SDU is stored.

[0017] A typical command used in the SDU management register is SDU Comp.
(Completion of SDU transf
er) and SDU Ready (response of response)
ready to write to the SD
U register). SDU Comp is
1 in the Thin transaction layer 407 on the transmitting side
This packet is issued to the receiving side when the transfer of the SDU is completed, and the SDU Ready is the packet of the receiving side.
This packet is issued to the transmission side when the reception of the next SDU is permitted after the processing of one SDU is completed in the n-session layer 406.

FIG. 10 shows a procedure for transferring file data from a transmitting node to a receiving node. It is assumed that the transferred data is divided into n SDUs.

In FIG. 10, each procedure is as follows: (1) In the Thin session layer of the transmitting node,
(2) Divide the SDU into 1394 packets in the Thin transaction layer of the transmitting node and transmit the 1394 packet to the receiving node (3) Complete transmission of all 1394 packets Later, SDU
Comp is issued to the receiving node. (4) In the Thin session layer of the receiving node,
After receiving the SDU, issue SDUReady to the transmitting node. The above processes (1) to (4) are repeated n times.

Therefore, if the transfer data is divided into n SDUs, n times of SDU Comp and SDU
Ready will be issued from the transmitting node and the receiving node, respectively. Here, SDU Comp or SDU Rea for the total transfer time
The time required for issuing and authenticating dy varies depending on the system configuration of the connected device, but is generally not negligible. Because SDU Com per time
Although the time required for issuing or authenticating p or SDU Ready is not large, it is not negligible because it is repeated n times before the transfer is completed. Therefore, n
Reduces the total transfer time, and for that purpose, it is necessary to increase the size of the SDU register area.

Hereinafter, a specific example will be described. If the SDU register area of the digital camera 500 is 32 kbytes (the microcomputer of each device has this value) and the SDU register area of the digital camera 501 is 64 kbytes, one SDU has the smaller SDU register size when connected. In this case, it is 32 kbytes. Therefore, the buffer size needs to be 32 kbytes or more.
If the register area is 128 kbytes, the SDU register size will be 64 kbytes, and the above-mentioned 1 SDU =
Since the number of SDUs to be transferred is halved compared to the case of 32 kbytes, the total number of bytes of the session header 703 added for each SDU is reduced, and at the same time, the SDU Com
The number of times that p or SDU Ready is issued is halved, and the transfer speed is increased. However, naturally, the buffer size also needs to be 64 kbytes or more.

In FIG. 11, the recording method of the digital camera 501 is changed to MPEG (Moving Picture Ex.
Parts group), which simply shows a circuit configuration at the time of recording on a recording medium, for example, an optical disk. FIG.
1, reference numeral 1000 denotes a camera unit; 101, an MPEG system unit that encodes output data from the camera unit;
01 is a buffer for temporarily storing the input 1394 packet, 1002 is a selector for selecting the input 1394 packet and the output data from the buffer 1001 by a selection signal from the microcomputer 106, and 102 is a memory, for example, a shockproof memory. Equivalent, 103 is the ECC
The (Error-Correcting Code) processing unit is used when performing error correction. 106 is buffer 1
001, a session header, an application header, and the like, and a microcomputer having a function of extracting only file data from the application data.
The C processing unit 103 and the replacement circuit 107 are controlled. Reference numeral 107 denotes a replacement circuit for moving data between the memory 102 and the ECC processing unit 103, and reference numeral 108 denotes a storage medium such as an optical disk.

With the above circuit configuration, the camera unit 1000
The video taken by is encoded by the MPEG system unit 101 and input to the memory 102. The data input to the memory 102 is transferred to the ECC processing unit 103 via the replacement circuit 107 under the control of the microcomputer 106, subjected to error correction processing, and recorded on the recording medium 108 at an appropriate timing controlled by the microcomputer 106. .

Here, the role of the memory 102 typified by a shock-proof memory is to prevent image skipping and sound skipping during real-time recording / reproduction, and is usually located immediately before a recording medium. For example, ECC processing unit 1
If the writing speed to the recording medium 108 becomes slower than the processing speed of the MPEG system unit 101 for some reason while the data held in the recording medium 03 is being recorded on the recording medium 108, real-time recording may be delayed. Will prevent it. That is, the recording medium 10 is not affected by external vibration or the like.
In the state where the recording has stopped and the recording is stopped, the data encoded by the MPEG system unit 101 is written to the memory 102, and after the recording returns to the normal state, the memory 102 By recording the data held in the storage medium 108, it is possible to prevent real-time recording from being interrupted.

By the way, the average rate of data compression in the MPEG system unit 101 is set to 10 Mbps (Mega
If it is set to “bit per second”, normally, the code data for about 5 to 10 seconds is stored in the memory 102 as the shock proof function, so that the capacity of the memory 102 is required to be 50 to 100 Mb. That is, the memory 10
2 requires a very large capacity.

On the other hand, when a 1394 packet is received, it is first inserted into the buffer 1001 for each SDU, and the data is analyzed by the microcomputer 106. The microcomputer 106 detects a session header, an application header, and the like, and finally extracts only file data from the application data. The extracted data is returned to the buffer 1001 again and output to the selector 1002. In the selector 1002 controlled by the microcomputer 106, 13
If the header information is present in the 94 packets, the data from the buffer 1001 is selected. If the 1394 packets are only file data, the input of the 1394 packets is directly selected. The output of the selector 1002 is also stored in the memory 1
02 to the ECC processing unit 103 via the replacement circuit 107 under the control of the microcomputer 106, and the recording medium 10 at an appropriate timing controlled by the microcomputer 106.
8 is recorded.

[0027]

With the circuit configuration as described above, file data is extracted from the received 1394 packet separately from the normal real-time recording / reproducing operation, and finally stored in a recording medium. Asynchronous transfer of 1394 packets is possible.
01, as described above, the buffer 10
It can be said that the transfer speed of the asynchronous transfer increases due to the large capacity of 01.

For example, FIG. 12 shows a 1-Mbyte file data transfer when the SDU register area is different.
First, each attribute value 1101 is added to the file data 1100 according to the FTC format. FIG.
, Each attribute value 1101 is 40 bytes, and an application header 1102 fixed at 24 bytes is added as described in the above-mentioned conventional example.

Next, a 16-byte fixed session header 1
Although the SDU with 103 is configured, if the SDU register area is 2048 bytes, the number of SDUs is 1
From 000064 / (2048-16) = 492.16, the total is 493, and the total value of the session header 1103 added for each SDU is 16 × 493 = 788
It is 8 bytes. However, the 493rd SDUll05
Does not result in 2048 bytes. Similarly, if the SDU register area is 32 kbytes, the number of SDUs is 100
From 0064 / (32k-16) = 31.27, a total of 3
2 session headers added to each SDU
The total value of 103 is 16 × 32 = 512 bytes.
However, the SDUll05 of 32 days does not become 32 kbytes.

That is, when the SDU register area is 2 kbytes and 32 kbytes, the number of bytes transferred after all is 7376 bytes (7
888-512). This value corresponds to 29 1394 packets, for example, when the size is 256 bytes.

This value can also be obtained by the following calculation. S
If the DU register area is 2048 bytes, 2048 /
From 256 = 8, it is divided into eight 1394 packets per SDU, and in the 1 Mbyte file data transfer,
From 8 × 492.16 = 3937.28, approximately 39
38 1394 packets will be transferred. On the other hand, if the SDU register area is 32 kbytes,
From 00/256 = 125, it is divided into 125 1394 packets per SDU, and in the case of 1 Mbyte file data transfer, approximately 3909 1394 packets are transferred from 125 × 31.27 = 3908.75. .

Therefore, when the capacity of the SDU register area, that is, the buffer 1001, is 2048 bytes,
In the case of bytes, 29 13
There is a difference of 94 packets.

Further, as described above, when the SDU register area is 2048 bytes and 32 kbytes, the number of divided SDUs is 493 and 32, respectively. Therefore, S
When the DU register area is 2048 bytes, SDU
The number of times of issuing or authenticating Comp or SDUReady increases 461 times (493-32), which greatly affects the total transfer time.

Further, the above-mentioned SDU Comp or
Since the number of SDU Ready issuances and authentications is equal to the number of SDUs to be divided, if transfer data increases, the total transfer time greatly increases.

Therefore, in order to speed up the asynchronous transfer even slightly, it is necessary to increase the capacity of the buffer 1001.

However, even when the capacity of the buffer 1001 is increased, it is sufficiently considered that the SDU register area of the connection destination node is larger than the SDU register area of the own node. However, there is a problem that the connection destination node has a redundant SDU register area.

Further, since the file transfer is an asynchronous transfer, even if the recording on the recording medium is interrupted for some reason, the file transfer can be stopped every time. Therefore, it is not necessary to increase the capacity as in a shock-proof memory. Absent.

Therefore, it is appropriate to prepare a buffer 1001 having a reasonable capacity value that is larger than the SDU register area of the connection destination and is not as large as the shock proof memory. Since it is free, the capacity of the buffer 1001 must be very large after all.

However, there is a problem that it is difficult to prepare a very large buffer 1001 as described above due to area restrictions, power consumption restrictions, and the like.

An object of the present invention is to provide an asynchronous transfer of 1394 packets by utilizing an existing large-capacity holding circuit without adding a new holding circuit such as a buffer. Is to make it possible.

[0041]

In order to solve the above problems, the present invention employs the following configuration.

Recording means for recording data on a recording medium,
In a data transfer method of a video or audio device comprising: a reproducing unit that reproduces data from the recording medium; a data holding unit that is used at the time of real-time recording or real-time reproduction on the recording medium; and an asynchronous transfer unit. The transfer means provides an area for asynchronous transfer in the data holding means, writes received data to the recording medium via the area for asynchronous transfer during reception in asynchronous transfer, and writes the received data to the recording medium during transmission in asynchronous transfer. A data transfer method for reading out transmission data via the asynchronous transfer area.

In the data transfer method, the recording means controls writing to the data holding means according to the amount of data stored in the data holding means, and the reproducing means controls the data stored in the data holding means. A data transfer method having a function of controlling reading from the data holding means in accordance with the amount of storage.

Further, in the data transfer system, a data transfer system in which the area of the asynchronous transfer area in the data holding means can be changed at any time.

Further, in the data transfer method, the data transfer means includes a plurality of the asynchronous transfer areas in the data holding means.

[0046]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An asynchronous data transfer system according to an embodiment of the present invention will be described below with reference to FIGS. FIG. 1 is a configuration example 1 of a digital camera that records a still image on a recording medium such as a magneto-optical disk by the MPEG method.
Is a block diagram showing the same or equivalent parts as those of the above-described prior art, and the same reference numerals are given to them, and the detailed description thereof is omitted.

As shown in the figure, 100 is a camera unit or a display unit, 101 is an MPEG system unit, 102 is a memory represented by a shock blue memory, and a shock proof area 104 and a newly provided asynchronous transfer area 105 Of SDU areas. 103 is E
A CC processing unit, 106 is a microcomputer, 107 is a replacement circuit, and 108 is a recording medium.

Here, the camera unit (or display unit) 100
The description of the operation of recording the video taken in step 1 on the recording medium 108 is the same as that described in the above-mentioned prior art, and thus is omitted.
The operation when transmitting and receiving 394 packets will be described.

When a 1394 packet is received, it is first inserted into the SDU area 105 in the memory 102 for each SDU, and the data is analyzed by the microcomputer 106. The microcomputer 106 detects a session header, an application header, and the like, and finally extracts only file data from the application data. Next, the extracted file data is returned to the SDU area 105, and under the control of the microcomputer 106, the file data is transferred from the SDU area 105 to the shock proof area 104 via the replacement circuit 107. Shock proof area 104
Then, the file data is transferred to the microcomputer 1 at appropriate timing.
Under the control of 06, the data is recorded on the recording medium 108 via the replacement circuit 107 and the ECC processing unit 103.

When transmitting the file data recorded on the recording medium 108 as 1394 packets, the file data is transferred from the recording medium 108 to the shock proof area 104 via the ECC processing unit 103 and the replacement circuit 107, and The data is returned to the SDU area 105 via the replacement circuit 107. Next, the microcomputer 106 reads the file data in the SDU area 105, adds a session header, an application header, and the like, and returns the data to the SDU area 105 again. Finally, in the SDU area 105, the microcomputer 1
By the control of 06, it is output at an appropriate timing as a 1394 packet.

Here, the shock-proof memory has a sufficient capacity for its purpose as shown in the above-mentioned conventional example, and has a capacity of at least 6 Mbytes (about 5 Mbytes).
0M bits). At the time of asynchronous transfer as shown in FIG.
Since it is not a real-time recording or playback, it does not require a shock-proof function.

That is, at the time of the asynchronous transfer, the memory 102 does not require the shock proof area 104 and can be used as a space of the SDU area 105.
Therefore, it is easy to secure an area for one SDU (for example, 32 kbytes) in the memory. Further, since the setting of the SDU register area can be changed by the microcomputer that controls each device, the shock proof is set. If the memory has enough capacity, it can be easily changed by changing the program installed in the microcomputer.

Therefore, in order to further increase the speed of the asynchronous transfer, the purpose can be easily achieved by changing the SDU register area to 128 kbytes or the like by changing the program mounted on the microcomputer.

As described above, in a video or audio device having a memory immediately before a storage medium, such as a shock blue memory, an area for IEEE 1394 asynchronous transfer is secured in the memory during asynchronous transfer. Therefore, it is not necessary to newly prepare a buffer for temporary storage, and S
The DU register area can be easily provided, and asynchronous transfer at a sufficient speed can be performed.

Further, according to this circuit configuration, the 1394 packet is stored in the memory without being processed by hardware, so that it does not depend on the protocol, and even if the protocol is changed, it can be handled by software.

FIG. 2 is a block diagram showing a configuration example 2 of a digital camera for recording a still image on a recording medium such as a magneto-optical disk by the MPEG method. Are denoted by the same reference numerals, and a detailed description thereof will be omitted. 2, the difference from the configuration example 1 shown in FIG. 1 is that an SDU area 109 is added to the memory 102, and the SDU area 109 is also an area for asynchronous transfer of one SDU like the SDU area 105.

Therefore, when a 1394 packet is received, first, the SDU area 10 in the memory 102 is
9 and the data is analyzed by the microcomputer 106. The microcomputer 106 detects a session header, an application header, and the like, and finally extracts only file data from the application data. Next, the extracted file data is returned to the SDU area 109, and the SDU area 105 is controlled by the microcomputer 106.
Replacement circuit 1 from shockproof area 104
07, the file data is transferred. In the shock proof area 104, the file data is stored at an appropriate timing by the control of the microcomputer 106 and the replacement circuit 107.
The data is recorded on the recording medium 108 via the ECC processing unit 103.

When transmitting the file data recorded on the recording medium 108 as 1394 packets, the file data is transferred from the recording medium 108 to the shock proofer 104 via the ECC processing unit 103 and the replacement circuit 107, and The data is returned to the SDU area 109 via the replacement circuit 107. Next, the microcomputer 106 reads the file data in the SDU area 109, adds a session header, an application header, and the like, and returns the data to the SDU area 109 again. Finally, in the SDU area 109, it is output at an appropriate timing as a 1394 packet under the control of the microcomputer 106.

Here, as shown in FIG. 3, a case is considered where a third digital camera 502 is connected via a hub 503 to the connection of the two digital cameras shown in FIG.
FIG. 3 shows a case where two types of file data recorded in the digital camera 500 are transferred to the digital camera 501 and the digital camera 502. For example, file data A recorded in the digital camera 500 is transferred to the digital camera 501. The file data B recorded in the digital camera 500 is stored in the digital camera 5.
02 is transferred asynchronously.

At this time, in order to perform the asynchronous transfer more efficiently, as shown in FIG.
It is desirable to prepare two U areas. This is because the SDU area in the memory 102 is 1 as shown in FIG.
In this case, for example, it is necessary to transfer the file data B after the transfer of the file data A is completely completed.
, The file data for one SDU of the file data A from the recording medium 108 is read into the SDU area 105, and then header information and the like are added from the SDU area 105 to the digital camera 50 as 1394 packets.
1, while reading the next 1 SDU of file data in the file data A into the SDU area 105, and further reading the file data B from the recording medium 108.
File data for one SDU in SDU area 1
09 can be read, and as a result, the transfer time of the two types of file data can be further reduced.

As described above, since the shock proofer 104 is not required in the memory 102 during asynchronous transfer, a plurality of SDU areas such as the SDU area 105 and the SDU area 109 can be secured.
Even when more than one device is connected, asynchronous transfer can be performed efficiently.

By the way, the examples of the configuration examples 1 and 2 described above are only examples, and the apparatus configuration and the processing method are as follows.
Various modifications are possible. For example, the MPEG system unit 101 can employ another encoding / decoding method, and the recording medium 108 is not limited to a magneto-optical disk. Also, the digital cameras 500, 501, and 502 represent video / audio devices capable of real-time recording or real-time reproduction and performing file transfer, but are not limited thereto. It can be applied to a case where a data holding circuit having a relatively large capacity is provided immediately before a medium and asynchronous data transfer is performed with another device.

[0063]

As described above, according to the present invention,
At the time of asynchronous transfer, by securing an area for asynchronous transfer in memory represented by shockproof memory,
A SDU register area having a changeable and reasonable size can be easily provided, and asynchronous transfer at a sufficient speed can be performed.

Further, according to this circuit configuration, since the 1394 packet is stored in the memory without being processed by hardware, it does not depend on the protocol, and even if the protocol is changed, it can be handled by software.

Further, at the time of asynchronous transfer, by securing a plurality of asynchronous transfer areas in a memory typified by the shockproof memory, the asynchronous transfer can be efficiently performed even when three or more devices are connected. It is possible to do.

[Brief description of the drawings]

FIG. 1 is a block diagram illustrating a configuration example of a data asynchronous transfer method according to a first embodiment of the present invention.

FIG. 2 is a block diagram illustrating a configuration example of a data asynchronous transfer method according to a second embodiment of the present invention.

FIG. 3 shows three digital cameras 139 via a HUB.
FIG. 4 is a connection diagram in which four cables are connected.

FIG. 4 is a schematic configuration diagram of a DPP.

FIG. 5 is a connection diagram in which two digital cameras are connected by a 1394 cable.

FIG. 6 is a diagram showing a schematic transmission operation (file transfer) of the DPP.

FIG. 7 is a diagram showing a schematic reception operation (file transfer) of the DPP.

FIG. 8 is a diagram showing a format of FTC.

FIG. 9 is a diagram illustrating a specific example of an FTC format.

FIG. 10 is a diagram showing a procedure when transferring file data from a transmitting node to a receiving node.

FIG. 11 is a block diagram of a conventional recording / reproducing apparatus.

FIG. 12 shows S in 1 Mbyte file data transfer.
It is a figure showing DU generation.

FIG. 13 is a diagram showing a CSR register space used in the Thin protocol.

[Explanation of symbols]

REFERENCE SIGNS LIST 100 Camera unit or display unit 101 MPEG system unit 102 Memory typified by shockproof memory 103 ECC processing unit 104 Shockproof area 105 SDU area 106 Microcomputer 107 Replacement circuit 108 Recording medium 109 SDU area 401 Command set group 402 Thin protocol layer 403 DPP 404 FTC (File Transfer Com)
mand Set) 405 DPC (Direct Print Comm)
and Set) 406 Thin session layer 407 Thin transaction layer 408 1394 transaction layer 409 Application layer 500, 501, 502 Digital camera 503 HUB 600, 706 Application data 601, 704 Segment data 602, 701 1394 packet 700 Sender node 702 SDU 703 session Header 705 Transfer data 707 Application header 800 Attribute name 801 901 Attribute length 802 902 Attribute type 803 903 Extension flag 804 Attribute value 900 “CMD0” 904 “PUT” 905 File data 1000 Camera unit 1001 Buffer 1002 Selector 1100 1 Mbyte File Motor 1101 40-byte session header 1104 and 1105 SDU of application header 1103 16 bytes of each attribute value 1102 24 bytes

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) // H04N 5/225 H04N 7/14 5K033 7/14 H04N 101: 00 5K034 H04N 101: 00 H04L 11/00 310D F term (reference) 5B065 BA01 CA11 CE11 5B082 HA05 HA10 5C022 AA12 AC31 AC69 AC75 5C052 AA03 AB04 CC11 DD04 DD06 5C064 AA06 AB04 AC04 AC18 AD02 AD06 AD14 5K033 BA01 BA15 CB06 DB12 EA03 H32H32H02H32H32H02H

Claims (4)

[Claims] Recording means for recording data on a recording medium; reproducing means for reproducing data from the recording medium; data holding means for use in real-time recording or real-time reproduction on the recording medium; and asynchronous transfer means. When,
In the data transfer method for video or audio equipment, the asynchronous transfer means includes an asynchronous transfer area in the data holding means, and when receiving in the asynchronous transfer, records the received data via the asynchronous transfer area. A data transfer method for writing data on a medium and reading out transmission data of the recording medium via the asynchronous transfer area during transmission in asynchronous transfer. 2. The data transfer method according to claim 1, wherein the recording unit controls writing to the data holding unit in accordance with a data storage amount of the data holding unit, A data transfer method comprising a function of controlling reading from said data holding means according to the amount of data stored in said data holding means. 3. The data transfer method according to claim 1, wherein an area of said asynchronous transfer area in said data holding means can be changed at any time. 4. The data transfer method according to claim 1, wherein said data holding means includes a plurality of said asynchronous transfer areas.