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

• US 7,822,898 B2
• Filed: 08/27/2007
• Issued: 10/26/2010
• Est. Priority Date: 01/18/2000
• Status: Expired due to Fees

• Current Assignee: Apple Inc.
• Original Assignee: Apple Inc.
• Inventors: Von Hauck, Jerrold, Whitby-Strevens, Colin
• Primary Examiner(s): Hafiz; Tariq
• Assistant Examiner(s): Vidwan; Jasjit S
• Application Number:
  US11/895,871
• Publication Number:
  US 20070294449A1
• Time in Patent Office: 1,156 Days
• Field of Search: 710/5, 710/8, 710/11, 710/14, 710/15, 710/29, 710/36, 710/107, 710/110, 710/112, 710/119, 710/305, 710/306, 710/200
• US Class Current: 710/107
• 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. A method of preventing a serial bus device from granting requests during one or more intervals of time, the method comprising:

determining whether the serial bus device has the right to grant requests among a first set of serial bus devices;

detecting the type of the serial bus;

selecting a protocol based at least in part upon the detected type of the serial bus; and

determining whether requests are presently allowed to be transmitted over the serial bus, wherein the determination is based at least in part upon the protocol;

wherein a first protocol allows the serial bus device to grant requests after receiving one of either (a) a first signal indicating the end of an isochronous packet or (b) a second signal indicating the end of an asynchronous packet and the end of a subaction has been detected; and

wherein the first protocol prohibits the serial bus from granting requests during an interval of time if the serial bus receives either (a) a third signal indicating the end of an asynchronous packet and the end of a subaction has not been detected or (b) a fourth signal indicating the end of an asynchronous packet and an acknowledgement has not been detected over the serial bus.

2. The method of claim 1, wherein said selecting a protocol further comprises selecting the first protocol if every device on the serial bus is compliant with a certain specification.

3. The method of claim 2, wherein the specification comprises the IEEE 1394b specification.

4. The method of claim 1, wherein the interval of time commences after the serial bus device receives the third or fourth signal indicating the end of the asynchronous packet.

5. The method of claim 1, wherein said selecting a protocol further comprises selecting a second protocol if not every device on the serial bus is compliant with a certain specification.

6. The method of claim 5, wherein said specification comprises the IEEE 1394b specification.

7. The method of claim 5, wherein if the serial bus device receives the first signal indicating the end of an isochronous packet, the second protocol prevents the serial bus device from granting requests during a first interval of time and a second interval of time.

8. The method of claim 7, wherein at least one of the first interval of time and the second interval of time is based at least in part on an idle period of bus activity and a period of hysteresis.

9. The method of claim 8, wherein the idle period of bus activity comprises a subaction gap.

10. The method of claim 8, wherein the idle period of bus activity comprises an arbitration reset gap.

11. The method of claim 8, wherein the period of hysteresis comprises an arbitration delay period.

12. The method of claim 7, wherein the second protocol allows the serial bus device to grant requests during a third interval of time, wherein the third interval of time occurs after the serial bus device receives the first signal indicating the end of an isochronous packet, but before the first interval of time.

13. The method of claim 7, wherein the second protocol allows the serial bus device to grant requests during a fourth interval of time, the fourth interval of time occurring after the first interval of time but before the second interval of time.

14. The method of claim 5, wherein if the serial bus device receives the third signal indicating the end of an asynchronous packet and the end of a subaction has not been detected, the serial bus device does not grant requests during the interval of time, the interval of time comprising a first interval of time and a second interval of time.

15. The method of claim 14, wherein at least one of the first interval of time and the second interval of time is based at least in part on an idle period of bus activity and a period of hysteresis.

16. The method of claim 15, wherein the idle period of bus activity comprises a subaction gap.

17. The method of claim 15, wherein the idle period of bus activity comprises an arbitration reset gap.

18. The method of claim 15, wherein the period of hysteresis comprises an arbitration delay period.

19. The method of claim 14, wherein the serial bus device grants requests during a third interval of time, the third interval of time occurring after the first interval of time but before the second interval of time.

20. The method of claim 5, wherein if the serial bus device receives the fourth signal indicating the end of an asynchronous packet but no acknowledgement, the serial bus device does not grant requests during the interval of time, the interval of time comprising a first interval of time and a second interval of time.

21. The method of claim 20, wherein the second protocol allows the serial bus device to grant requests during a third interval of time, wherein the third interval of time occurs after the first interval of time but before the second interval of time.

22. The method of claim 5, wherein if the serial bus device receives the second signal indicating the end of an asynchronous packet and detects the end of a subaction, the serial bus device does not grant requests during a first interval of time.

23. The method of claim 22, wherein the first interval of time is based at least in part on an idle period of bus activity and a period of hysteresis.

24. The method of claim 23, wherein the idle period of bus activity comprises an arbitration reset gap.

25. The method of claim 23, wherein the period of hysteresis comprises an arbitration delay period.

26. The method of claim 22, wherein the second protocol allows the serial bus device to grant requests after receiving the second signal indicating the end of the asynchronous packet, but before the first interval of time.

27. The method of claim 1, wherein said determining whether the serial bus device has the right to grant requests comprises determining whether the serial bus device has received a first symbol.

28. The method of claim 1, wherein said determining whether the serial bus device has the right to grant requests comprises determining whether the serial bus device has received a second symbol over a junior port.

29. The method of claim 28, wherein the second symbol comprises a data end symbol.

30. The method of claim 1, wherein said determining whether the serial bus device has the right to grant requests comprises determining whether the serial bus device has transmitted a packet into a designated group of serial bus devices.

31. A method for controlling when a serial bus device on a hybrid bus is able to grant requests, the method comprising:

preventing the serial bus device from granting requests during a first interval of time, said first interval of time comprising a first idle period of bus activity that comprises an arbitration reset gap and a first period of hysteresis comprising an arbitration delay period;

wherein the first interval of time commences after a second interval of time and a third interval of time, the second interval of time comprising a second idle period of bus activity and a second period of hysteresis, the third interval of time occurring after the second interval of time but before said first interval of time; and

allowing the serial bus device to grant requests during the second interval of time only when the end of an asynchronous packet has been detected and the end of a subaction has been detected.

32. The method of claim 31, further comprising:

allowing the serial bus device to grant requests during the third interval of time.

33. An apparatus adapted to prevent a serial bus device from granting requests during one or more intervals of time, the apparatus comprising:

a first module adapted to determine whether the serial bus device can grant requests among a first set of serial bus devices;

a second module adapted to detect the type of the serial bus;

a third module adapted to select a protocol based at least in part upon the detected type of the serial bus; and

a fourth module adapted to determine whether requests are presently allowed to be transmitted over the serial bus, said determination based at least in part upon said protocol;

wherein a first protocol allows the serial bus device to grant requests after receiving one of either (a) a first signal indicating the end of an isochronous packet or (b) a second signal indicating the end of an asynchronous packet and the end of a subaction has been detected; and

wherein the first protocol prohibits the serial bus from granting requests during an interval of time if the serial bus receives either (a) a third signal indicating the end of an asynchronous packet and the end of a subaction has not been detected or (b) a fourth signal indicating the end of an asynchronous packet and an acknowledgement has not been detected over the serial bus.