SYSTEM AND METHOD FOR PACKET MESSAGING AND SYNCHRONIZATION

• US 20100272102A1
• Filed: 04/22/2010
• Published: 10/28/2010
• Est. Priority Date: 04/23/2009
• Status: Abandoned Application

• Current Assignee: STMicroelectronics Incorporated (STMicroelectronics NV)
• Original Assignee: STMicroelectronics Incorporated (STMicroelectronics NV)
• Inventors: KOBAYASHI, Osamu
• Application Number:
  US12/765,760
• Publication Number:
  US 20100272102A1
• Time in Patent Office: Days
• US Class Current: 370/389
• CPC Class Codes: H04J 3/0667 Bidirectional timestamps, e.g. NTP or PTP for compensation of clock drift and for compensation of propagation delays arrangements for monitoring round trip delays in packet switching networks H04L43/0864
• CPC Class Codes: H04L 69/08 Protocols for interworking; Protocol conversion
• CPC Class Codes: H04L 69/18 Multiprotocol handlers, e.g. single devices capable of handling multiple protocols
• CPC Class Codes: H04L 69/326 in the transport layer [OSI layer 4] H04L69/16 takes precedence
• CPC Class Codes: H04N 21/4305 Synchronising client clock from received content stream, e.g. locking decoder clock with encoder clock, extraction of the PCR packets arrangements for synchronising receiver with transmitter by comparing receiver clock with transmitter clock H04L7/0012; arrangements for synchronising receiver with transmitter wherein the receiver takes measures against momentary loss of synchronisation H04L7/0083
• CPC Class Codes: H04N 21/43632 involving a wired protocol, e.g. IEEE 1394 high-speed IEEE 1394 serial bus H04L12/40052

Abstract

System and method for packet messaging and synchronization through a packet based display interface includes using a multiple packet transport protocols, translating packet messages between protocols and achieving time code synchronization with a packet protocol between multiple devices in a multimedia network. A packet based display interface includes a dual data transport module to communicate packet messages using first and second packet transport protocols across a bidirectional link and a media transport module to communicate video packets across a unidirectional link. A method for communicating packet messages between source and slave devices in a multimedia network includes translating messages between different packet transport protocols. An apparatus for synchronizing a sink device to a source device includes a counter module configured to be adjusted based on a received source global time code value and a transport module to transmit a sink global time code value to the source device.

Claims

1. A packet based display interface configured to operate in a multimedia device in a network, the interface comprising:

a media transport module configured to communicate video packets across a first unidirectional link;

a dual data transport module configured to communicate packet messages, in transit to or from a first sideband message handler client service module, across a bidirectional link using a first packet transport protocol or a second packet transport protocol;

a detection module configured to receive an interrupt signal on a second unidirectional link opposite in direction to the first unidirectional link; and

an event monitor client service module configured to determine the availability of a packet message from a second sideband message handler client service module across the bidirectional link based on the received interrupt signal;

wherein the first and second unidirectional links and the bidirectional link each use separate physical communication lines bundled together in a common cable.

2. In a packet based display interface, a method for communicating a packet message between a master client service module in a source device and a slave device attached to a sink device across a bidirectional link that connects the source device to the sink device in a multimedia network, the method comprising:

detecting by a first translation module in the sink device availability of a first packet message from the slave device attached to the sink device to communicate through the bidirectional link to the master device;

setting a status indication in a first client service module in the sink device indicating availability of the packet message;

transmitting the status indication of the first client service module to a second client service module in the source device in response to a status request from the second client service module;

sending a read request from a second translation module in the source device to the sink device in response to the transmitted status indication;

translating by the first translation module in the sink device the first packet message from the slave device that uses a first packet transport protocol into a second packet message formatted using a second packet transport protocol;

transmitting the second packet message from the sink device to the source device across the bidirectional link;

translating by the second translation module in the source device the received second packet message formatted using the second packet transport protocol back into the first packet message formatted using the first packet transport protocol; and

delivering the first packet message to the master client service module in the source device.

3. A packet based display interface having an apparatus in a sink device for synchronizing the sink device to a source device in a multimedia network, the apparatus comprising:

a local sink reference clock module configured to generate a sink link clock signal;

a unidirectional main link transport module configured to receive multimedia packets at a symbol rate determined by the sink link clock signal;

a counter module configured to increment a value of a sink global time code register based on the sink link clock signal;

a bidirectional auxiliary channel transport module configured to receive a source global time code value from the source device and to transmit a subsequent sink global time code value to the source device;

wherein the value of the sink global time code register in the counter module is configured to be adjusted based on the received source global time code value.