Fly-by serial bus arbitration

• US 20040246959A1
• Filed: 07/02/2004
• Published: 12/09/2004
• Est. Priority Date: 12/01/1995
• Status: Active Grant

• Current Assignee: Apple Inc.
• Original Assignee: Apple Inc.
• Inventors: Duckwall, William S., Teener, Michael D.
• Granted Patent: US 8,155,112 B2
• Time in Patent Office: Days
• US Class Current: 370/389
• CPC Class Codes: H04L 12/40058 Isochronous transmission
• CPC Class Codes: H04L 12/40084 Bus arbitration
• CPC Class Codes: H04L 12/40136 Nodes adapting their rate to the physical link properties LAN switches H04L49/351
• CPC Class Codes: H04L 12/417 with deterministic access, e.g. token passing
• CPC Class Codes: H04L 69/18 Multiprotocol handlers, e.g. single devices capable of handling multiple protocols
• CPC Class Codes: H04L 69/323 in the physical layer [OSI layer 1]
• CPC Class Codes: H04L 69/324 in the data link layer [OSI layer 2], e.g. HDLC
• CPC Class Codes: H04L 9/40 Network security protocols

Abstract

In a first embodiment, multi-speed concatenated packet strings are transmitted by a first node on a serial bus. To accommodate multi-speed packets, a speed signal is transmitted immediately prior to the packet. In a second embodiment, ACK-concatenation is used to allow a node to transmit a data packet immediately after transmitting an acknowledge signal on the bus. The data packet need not be related to the ACK packet. In a third embodiment, a node which receives a first data packet followed by a data end signal on a child port, concatenates a second data packet onto the first data packet during retransmission. The second data packet is also transmitted down the bus in the direction of the node which origmally transmitted the first data packet.

Claims

1-19. -19 (Canceled)

20. A machine-readable medium having executable instructions to cause a node that is operable to couple to a serial bus configured in accordance with the IEEE-1394 Serial Bus Standard to perform a method of transmitting data packets comprising:

transmitting a first speed signal for a first data packet to be transmitted on the serial bus by the node;

transmitting the first data packet at the first speed on the serial bus by the node;

transmitting a second speed signal for a second data packet to be transmitted on the serial bus by the node; and

transmitting the second data packet at the second speed on the serial bus by the node.

21. The machine-readable medium of claim 20, wherein the node comprises a physical layer and a link layer.

22. The machine-readable medium of claim 21, wherein the first speed signal is part of a first data prefix signal.