Method and apparatus for border node behavior on a full-duplex bus

• US 7,490,174 B2
• Filed: 11/16/2006
• Issued: 02/10/2009
• Est. Priority Date: 01/18/2000
• Status: Expired due to Fees

• Current Assignee: Apple Inc.
• Original Assignee: Apple Inc.
• Inventors: Whitby-Strevens, Colin, Hauck, Jerrold V.
• Primary Examiner(s): Hafiz; Tariq
• Assistant Examiner(s): Vidwan; Jasjit S
• Application Number:
  US11/601,487
• Publication Number:
  US 20070067523A1
• Time in Patent Office: 817 Days
• Field of Search: 710/5, 710/8, 710/72
• US Class Current: 710/8
• CPC Class Codes: H04L 12/40052 High-speed IEEE 1394 serial bus bus transfer protocol on a daisy chain bus using an embedded synchronisation G06F13/426
• 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 12/6418 Hybrid transport

Abstract

A method and apparatus relating to the behavior of border nodes within a high performance serial bus system is disclosed.

A method for determining and communicating the existence of a hybrid bus is disclosed. A method for determining a path to a senior border node is disclosed, as is a method for identifying a senior border node Various methods for properly issuing gap tokens within a beta cloud are disclosed.

Claims

1. In a communications system comprising at least one serial bus, at least one node operating only in a first mode, and at least one other node operating in a second mode, a border apparatus comprising:

a first port operatively coupled to said at least one node operating in said first mode;

a second port operatively coupled to said at least one node operating in said second mode; and

a transfer apparatus adapted to transfer gap timing requirements associated with said at least one node operating in said second mode to said border apparatus, said transfer apparatus further adapted to, upon completion of transfer tasks, turn over control to a senior border apparatus operating in said second mode for management of gap timing by said senior border apparatus.

2. The border apparatus of claim 1, wherein said border apparatus operates according to a hybrid bus communication protocol.

3. The border apparatus of claim 2, wherein said system comprises a full-duplex communications system.

4. The border apparatus of claim 2, wherein said first mode comprises a legacy mode, and said second mode comprises a mode which is accelerated relative to said legacy mode.

5. The border apparatus of claim 2, wherein said hybrid bus communication protocol comprises regulating an idle duration of said at least one other node operating in said second mode.

6. The border apparatus of claim 5, wherein said hybrid bus communication protocol further comprises:

detecting a first idle duration which is related to a subaction gap, and issuing an asynchronous start signal in response thereto; and

detecting a second idle duration which is related to an arbitration reset gap, and issuing an arbitration reset signal in response thereto.

7. The border apparatus of claim 2, wherein said hybrid bus communication protocol is further adapted to enforce proper arbitration between said border apparatus and said at least one node operating in said second mode, even if said at least one node operating in said first mode comprises a parent of said border apparatus.

8. The border apparatus of claim 4, wherein said legacy mode comprises a mode compliant with IEEE Std. 1394a, and said accelerated mode comprises a mode compliant with IEEE Std. 1394b.

9. In a communications system comprising at least one serial bus, a method of transferring gap timing requirements to a border apparatus, comprising:

operatively coupling a first port of said border apparatus to a node operating in a first mode;

operatively coupling a second port of said border apparatus to a node operating in a second mode;

detecting a duration of idle timing;

if said duration is equal to a first predetermined value, then issuing a first message; and

if said duration is equal to a second predetermined value, then issuing a second message;

if no senior node is connected to said node operating in said second mode of said border apparatus, then transferring gap timing requirements associated with said node operating in said second mode to said border apparatus; and

if a senior node is connected to said node operating in said second mode of said border apparatus, then transferring control of gap timing requirements to said senior node.

10. The method of claim 9, further comprising:

operating said border apparatus according to a hybrid bus communication protocol.

11. The method of claim 10, wherein said communication system comprises a full-duplex communication system.

12. The method of claim 11, wherein said first mode comprises a legacy mode, and said second mode comprises a mode which is accelerated relative to said legacy mode.

13. The method of claim 12, wherein said legacy mode comprises a mode compliant with IEEE Std. 1394a, and said accelerated mode comprises a mode compliant with IEEE Std. 1394b.

14. The method of claim 10, wherein said hybrid bus communications protocol comprises regulating an idle duration of said node operating in said second mode.

15. The method of claim 14, wherein said hybrid bus communication protocol further comprises:

enforcing proper arbitration between said border apparatus and said node operating in said second mode, even if said node operating in said first mode comprises a parent of said border apparatus.

33. The method of claim 9, wherein said first message comprises a start message, and said second message comprises a reset message.

34. The method of claim 9, wherein said second mode comprises a mode which is accelerated relative to said first mode.

16. A full duplex communications system, comprising:

a serial bus;

at least one node operating in a first mode operatively coupled to said serial bus;

at least one other node operating in a second mode operatively coupled to said serial bus; and

a plurality of border apparatus each comprising;

a first port operatively coupled to said at least one node operating in said first mode; and

a second port operatively coupled to said at least one node operating in said second mode;

wherein each of said plurality of border apparatus utilizes low-priority arbitration to select one of said plurality of border apparatus as a boss node before an prescribed period of idle time appears on said serial bus, said boss node being responsible for arbitration on said serial bus.

17. The full duplex communications system of claim 16, wherein said border apparatus operates according to a hybrid bus communication protocol.

18. The full duplex communications system of claim 16, wherein said first mode comprises a legacy mode, and said second mode comprises a mode which is accelerated relative to said legacy mode.

19. The full duplex communications system of claim 18, wherein said legacy mode comprises a mode compliant with IEEE Std. 1394a, and said accelerated mode comprises a mode compliant with IEEE Std. 1394b.

20. The full duplex communications system of claim 17, wherein said hybrid bus communication protocol comprises regulating an idle duration of said at least one other node operating in said second mode.

21. The full duplex communications system of claim 20, wherein said hybrid bus communication protocol further comprises:

detecting a first idle duration which is related to a subaction gap, and issuing an asynchronous start signal in response thereto; and

detecting a second idle duration which is related to an arbitration reset gap, and issuing an arbitration reset signal in response thereto.

22. The full duplex communications system of claim 17, wherein said hybrid bus communication protocol is further adapted to enforce proper arbitration between said border apparatus and said at least one other node operating in said second mode, even if said at least one node operating in said first mode comprises a parent of said border apparatus.

23. For use in a communications system comprising at least one serial bus, at least one node operating in a first mode, and at least one other node operating in a second mode, a border apparatus comprising:

a first interface adapted for data communication with said at least one node operating in said first mode;

a second interface adapted for data communication with said at least one node operating in said second mode;

apparatus adapted to, at said border apparatus, receive gap timing requirements associated with said at least one node operating in said second mode; and

apparatus adapted to, at said border apparatus, detect a duration of idle timing and;

if said duration is equal to a first predetermined value, then issue a first predetermined message;

if said duration is equal to a second predetermined value, then issue a second predetermined message; and

apparatus adapted to, at said border apparatus, transfer gap timing requirements associated with said node operating in said second mode responsive to whether a senior border node operating in said second mode is connected to said at least one serial bus.

24. The border apparatus of claim 23, wherein said border apparatus operates according to a hybrid bus communication protocol.

25. The border apparatus of claim 24, wherein said system comprises a full-duplex communications system.

26. The border apparatus of claim 24, wherein said second mode comprises a mode which is accelerated in at least data rate relative to said first mode.

27. The border apparatus of claim 24, wherein said hybrid bus communication protocol comprises regulating an idle duration of said at least one other node operating in said second mode.

28. The border apparatus of claim 24, wherein said hybrid bus communication protocol is further adapted to enforce proper arbitration between said border apparatus and said at least one node operating in said second mode, even if said at least one node operating in said first mode comprises a parent of said border apparatus.

29. The border apparatus of claim 26, wherein said first mode comprises a mode compliant with IEEE Std. 1394a, and said accelerated mode comprises a mode compliant with IEEE Std. 1394b.

30. The border apparatus of claim 23, wherein at least one of said nodes operating in said first or second modes is adapted for hot plug connection to said border apparatus or a device interposed in a data communication path there between.

31. The border apparatus of claim 23, wherein said first mode comprises a first high-speed serialized bus protocol, and said second mode comprises a second high-speed serialized bus protocol, said first and second protocols not being identical.

32. The border apparatus of claim 23, wherein at least one of said nodes operating in said first or second modes comprises a hand-held video capable device.

35. For use in a communications system comprising at least one serial bus, at least one node operating only in a first mode, and at least one other node operating in a second mode, border apparatus comprising:

a first interface operatively coupled to at least one node operating in said first mode;

a second interface operatively coupled to said at least one node operating in said second mode; and

transfer apparatus adapted to transfer gap timing requirements associated with said at least one node operating in said second mode to said border apparatus, said transfer apparatus further adapted to turn over control to a senior border apparatus operating in said second mode for management of gap timing.

36. The apparatus of claim 35, wherein said second mode comprises a mode which is accelerated relative to said first mode.

37. The apparatus of claim 36, wherein said first mode comprises a mode compliant with IEEE Std. 1394a, and said second mode comprises a mode compliant with IEEE Std. 1394b.

38. In a communications system comprising at least one serial bus, a border apparatus operatively coupled to a node operating in a first mode and to another node operating in a second mode, said another node having no senior node operatively coupled thereto, a method of transferring gap timing requirements comprising:

evaluating a duration of idle timing;

based at least in part on said evaluating, issuing a message of either a first type or of a second type to one of said nodes; and

transferring gap timing requirements associated with said node operating in said second mode to said border apparatus.

39. The method of claim 38, wherein said second mode comprises a mode which is accelerated relative to said first mode, and said first type of message performs a different function than said second type of message.

40. The method of claim 38, wherein said evaluating comprises determining if said duration meets one of first or second criteria.

41. In a communications system comprising at least one serial bus, a border apparatus operatively coupled to a node operating in a first mode and to another node operating in a second mode, said another node having a senior node operatively coupled thereto, a method of transferring gap timing requirements comprising:

evaluating a duration of idle timing;

based at least in part on said evaluating, issuing a first or second message to at least one of said nodes that is consistent with said at least one node operating in either said first mode or said second mode, respectively; and

transferring control of gap timing requirements to said senior node.

42. The method of claim 41, wherein said second mode comprises a mode which is accelerated relative to said first mode, and said first type of message performs a different function than said second type of message.

43. The method of claim 41, wherein said evaluating comprises determining if said duration meets one of first or second criteria.