Data communication method

• US 5,933,430 A
• Filed: 08/09/1996
• Issued: 08/03/1999
• Est. Priority Date: 08/12/1995
• Status: Expired due to Term

• Current Assignee: Sony Corporation (Sony Group Corp.)
• Original Assignee: Sony Corporation (Sony Group Corp.)
• Inventors: Shima, Hisato, Sato, Makoto, Osakabe, Yoshio
• Primary Examiner(s): MARCELO, MELVIN C
• Application Number:
  US08/694,592
• Time in Patent Office: 1,089 Days
• Field of Search: 370/395, 370/463, 370/476
• US Class Current: 370/463
• CPC Class Codes: G10H 1/0066 using a MIDI interface
• CPC Class Codes: G10H 2240/315 Firewire, i.e. transmission according to IEEE1394
• CPC Class Codes: G11B 2220/2529 Mini-discs
• CPC Class Codes: G11B 2220/2545 CDs
• CPC Class Codes: G11B 2220/90 Tape-like record carriers
• CPC Class Codes: G11B 2220/913 Digital audio tape [DAT] format
• CPC Class Codes: G11B 27/031 Electronic editing of digitised analogue information signals, e.g. audio or video signals
• CPC Class Codes: H04J 3/0632 Synchronisation of packets and cells, e.g. transmission of voice via a packet network, circuit emulation service [CES] queuing arrangements in packet switching elements H04L49/90; synchronising systems for the synchronous transmission of a pulse code modulated video signal with one or more other pulse code modulated signals H04N7/56
• CPC Class Codes: H04L 12/40058 Isochronous transmission
• CPC Class Codes: H04L 12/40071 Packet processing; Packet format adaptation of digital video signals for transport over a specific network H04N21/2381, H04N21/4363, H04N21/4381; packet switches H04L49/00; intermediate storage or scheduling H04L49/90
• CPC Class Codes: H04L 12/40117 Interconnection of audio or video/imaging devices home automation networks H04L12/2803; bitstream network arrangements specially adapted for distribution of digital video signals H04N7/24
• CPC Class Codes: H04N 21/43632 involving a wired protocol, e.g. IEEE 1394 high-speed IEEE 1394 serial bus H04L12/40052
• CPC Class Codes: H04N 21/8106 involving special audio data, e.g. different tracks for different languages

Abstract

It is an object of the present invention to reduce the number of terminals in an equipment for inputting or outputting a realtime digital signal such as a digital audio signal and a music/musical instrument signal. A first converter and a second converter are provided with a function of mutual conversion between a signal format of a digital audio interface and a signal format of IEEE-1394. For example, it is possible to transmit a signal of a digital audio interface outputted from a first CD player to the first converter, to convert the signal here into a packet of IEEE-1394 isochronous transmission format and transmit it to the second converter, and to return the packet to the digital audio interface and record a digital audio signal in an MD recorder. When a converter having a function of mutual conversion between the MIDI signal format and the IEEE-1394 signal format is provided, it is also possible to perform bidirectional data communication among a plurality of MIDI musical instruments.

Claims

1. A data communication method, comprising:

converting a format of a first interface for use in transmitting digital data unidirectionally to an isochronous transmission format of a second interface for use in transmitting digital data bidirectionally, said first interface using said digital data unidirectionally having a sampling frequency selected from a number of sampling frequencies;

converting a control signal to an asynchronous transmission format of said second interface; and

transmitting said control signal in said asynchronous transmission format time-divisionally multiplexed with said digital data in said isochronous transmission format represented by a plurality of data blocks, the length of each data block being set to a combination of a predetermined number of data packets which is the same for each of the selected sampling frequencies of said first interface and a remaining number of dummy packets according to said each selected sampling frequency.

2. The data communication method according to claim 1, wherein the digital data are music/musical instrument signals.

3. The data communication method according to claim 2, wherein the music/musical instrument signal is transmitted in said asynchronous transmission format for audio/video equipment.

4. The data communication method according to claim 1, wherein said control signal is selectively transmitted via another interface connected to said first interface for transmitting digital data unidirectionally or via an apparatus provided with said first interface.

5. The data communication method according to claim 4, wherein the digital data are digital audio signals.

6. The data communication method according to claim 1, wherein a header that belongs to a packet of said isochronous transmission format is made common to a number of types of digital data.

7. The data communication method according to claim 1, wherein a header is equipped with an identification code for identifying a mode of transmitting synchronously with a cycle of isochronous transmission from a mode of transmitting asynchronously therewith for a number of types of digital data.

8. The data communication method according to claim 1, wherein an identification code for identifying the type of digital data is added to the data of said isochronous transmission format.

9. The data communication method according to claim 1, wherein a synchronous signal of said first interface for transmitting digital data unidirectionally is bit-compressed such that the signal is inserted into a header of isochronous transmission of said second interface for transmitting digital data bidirectionally.

10. Data communication apparatus, comprising:

isochronous converting means for converting a format of a first interface for use in transmitting digital data unidirectionally to an isochronous transmission format of a second interface for use in transmitting digital data bidirectionally, said first interface using said digital data unidirectionally having a sampling frequency selected from a number of sampling frequencies;

asynchronous converting means for converting a control signal to an asynchronous transmission format of said second interface; and

means for transmitting said control signal in said asynchronous transmission format time-divisionally multiplexed with said digital data in said isochronous transmission format represented by a plurality of data blocks, the length of each data block being set to a combination of a predetermined number of data packets which is the same for each of the selected sampling frequencies of said first interface and a remaining number of dummy packets according to said each selected sampling frequency.

11. The data communication apparatus according to claim 10, wherein the digital data include signals from musical instruments.

12. The data communication apparatus according to claim 10, wherein the digital data include digital audio signals.

13. A data communication converter, comprising:

a link layer unit for converting a format of a first interface for use in transmitting digital data unidirectionally to an isochronous transmission format of a second interface for use in transmitting digital data bidirectionally, said first interface using said digital data unidirectionally having a sampling frequency selected from a number of sampling frequencies, said converter converting a control signal to an asynchronous transmission format of said second interface; and

a physical layer unit for transmitting said control signal in said asynchronous transmission format time-divisionally multiplexed with said digital data in said isochronous transmission format represented by a plurality of data blocks, the length of each data block being set to a combination of a predetermined number of data packets which is the same for each of the selected sampling frequencies of said first interface and a remaining number of dummy packets according to said each selected sampling frequency.

14. The data communication converter according to claim 13, wherein the data packets comprise an identification code for distinguishing between a mode of transmitting synchronously with a cycle of isochronous transmission and another mode of transmitting asynchronously for a number of types of digital data.

15. The data communication converter according to claim 13, wherein an identification code for identifying the type of digital data is added to the data of said isochronous transmission format.

16. The data communication converter according to claim 13, wherein the signal of said first interface for transmitting digital data unidirectionally is bit-compressed such that the signal is inserted into a header of isochronous transmission of said second interface for transmitting digital data bidirectionally.