Communication control method, communication system and electronic device used therefor

• US 6,286,071 B1
• Filed: 03/07/2000
• Issued: 09/04/2001
• Est. Priority Date: 07/09/1998
• Status: Expired due to Term

• Current Assignee: Sony Corporation (Sony Group Corp.)
• Original Assignee: Sony Corporation (Sony Group Corp.)
• Inventors: Iijima, Yuko
• Primary Examiner(s): Nguyen, Viet Q.
• Application Number:
  US09/520,907
• Time in Patent Office: 546 Days
• Field of Search: 710/5, 710/15, 710/20, 710/24, 710/25, 710/29, 710/36, 710/124, 713/300
• US Class Current: 710/124
• CPC Class Codes: H04L 12/40084 Bus arbitration
• 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: H04L 12/413 with random access, e.g. carrier-sense multiple-access with collision detection [CSMA-CD]
• CPC Class Codes: H04L 12/64 Hybrid switching systems

Abstract

A communication system includes a communication control section which may receive bus use requests of both of a DV camera/recorder (50) which becomes an output machine on a serial bus (60D) and a DV deck (40) which becomes an input machine on the serial bus (60D), may check whether or not the serial bus (60D) which were requested to be used is in use, may open the serial bus (60D) to the DV camera/recorder (50) and the DV deck (40) which issued the use requests, may protect a connection between the DV camera/recorder (50) and the DV deck (40), may open a serial bus (60A) to an IRD receiver (10) and a mini disc (20) which issued use requests and which may protect a connection between the IRD receiver (10) and the mini disc (20). According to this arrangement, even when data used on a communication control bus have different signal formats, a communication control bus of other specific interval in which the use requests are not overlapped can be used simultaneously by other electronic devices, and such communication control bus can be used effectively.

Claims

1. In a method of controlling a communication between a plurality of electronic devices connected by a communication control bus in a daisy-chain fashion, said communication control method comprising the steps of:

receiving bus use requests from both of an electronic device serving as an output machine on said communication control bus and an input machine serving as an input machine on said communication control bus;

checking whether or not a specific interval of said communication control bus which was requested in bus use is used; and

opening said communication control bus of the specific interval to an electronic device of a signal input/output pair which were requested in use and protecting a connection between said electronic devices if said communication control bus of the specific interval from which said bus use request was issued is not in use.

2. A communication control method as claimed in claim 1, wherein said bus use requests from both of an electronic device which becomes an output machine on a remaining communication control bus and an electronic bus which becomes an input machine on said remaining communication control bus are received when a communication control bus of said specific interval which was requested to be used, it is checked whether or not other specific interval of the communication control bus which was requested to be used is in use, the communication control bus of said specific interval is made open to an electronic device of other signal input and output pair and a connection between said electronic devices is protected if the communication control bus of other specific interval which was requested to be used is not in use.

3. A communication control method as claimed in claim 1, wherein said electronic device which becomes an output machine on said communication control bus effects an error processing for notifying a message indicating that data cannot be outputted if the communication control bus of said specific interval which was requested to be used is in use.

4. A communication control method as claimed in claim 1, wherein said electronic device which becomes an input machine on said communication control bus effects an error processing for notifying a message indicating that data cannot be outputted if the communication control bus of said specific interval which was requested to be used is in use.

5. A communication control method as claimed in claim 1, wherein said communication control bus is an IEEE 1394 standard serial bus.

6. In a communication system in which a plurality of electronic devices are connected by a communication control bus in a daisy-chain fashion, a communication control system includes bus management control means which receives bus use requests of both of an electronic device which becomes an output machine on said communication control bus and an electronic device which becomes an input machine on said communication control bus, said bus management control means checks whether or not a specific interval of the communication control bus which was requested to be used is in use, said bus management control means opens the communication control bus of said specific interval to electronic devices of signal input and output pair which issued said requests to use bus and which protects a connection between said electronic devices if the communication control bus of said specific interval which was requested to be used is not in use.

7. A communication system as claimed in claim 6, further comprising memory means for memorizing a plurality of bus management default channels which can connect an electronic device which becomes an output machine on said communication control bus and an electronic device which becomes an input machine on said communication control bus and bus management control means for monitoring bus management default channels stored in said memory means, controlling the electronic device which becomes said output machine so as to output data to said default channels and controlling said electronic device such that said electronic device outputs data to said default channels if said default channel is protected, controlling the electronic device which becomes said input machine so as to input data from said default channel and controlling said electronic device such that data is inputted from said unoccupied default channel if said default channel is protected.

8. A communication system as claimed in claim 6, wherein the output machine which can flow data uselessly to said communication control bus includes bus management control means for limiting the number of electronic devices to one.

9. A communication system as claimed in claim 6, wherein the electronic device which becomes an output machine on said communication control bus includes display means for notifying a message indicating that data cannot be outputted if the communication control bus of the specific interval which was requested to be use is in use.

10. A communication system as claimed in claim 6, wherein the electronic device which becomes an input machine on said communication control bus includes display means for notifying a message indicating that data cannot be outputted if the communication control bus of the specific interval which was requested to be use is in use.

11. A communication system as claimed in claim 6, wherein said control means is provided in any one of a plurality of electronic devices connected to said communication control bus.

12. A communication system as claimed in claim 6, wherein said control means is provided in all electronic devices connected to said communication control bus.