SNAA333 April   2020 CDCE6214-Q1

 

  1.   eAVB Media Clock Synchronization Using CDCE6214-Q1 Clock Generator
    1.     Trademarks
    2. 1 Introduction
    3. 2 AVB Protocols and Network Structure
    4. 3 AVB End Station Architecture
    5. 4 Talker, Listener, Presentation Time, and Media Clock Synchronization
      1. 4.1 Talker and Presentation Time
      2. 4.2 Listener and Media Clock Synchronization
    6. 5 Reference CDCE6214-Q1 Schematic and Programming Guide
    7. 6 Summary
    8. 7 References

2 AVB Protocols and Network Structure

AVB is a family of protocols that include:

  1. IEEE 802.1AS for time synchronization. IEEE 802.1AS defines generalized Precision Time Protocol (gPTP) profile based on IEEE 1588.
  2. IEEE 802.1Qav for traffic shaping.
  3. IEEE 802.1Qat for stream reservation.
  4. IEEE 802.1BA that specifies defaults and profiles of AVB components. IEEE 802.1BA is an umbrella standard for IEEE 802.1AS, IEEE 802.1Qav and IEEE 802.1Qat.
  5. IEEE 802.1Q that specifies Virtual Bridged Local Area Networks. IEEE 802.1Qav and IEEE 802.1Qat have been incorporated to IEEE 802.1Q.
  6. IEEE 1722 Layer 2 A/V transport protocol.

    An example AVB system is shown in Figure 2:

    02-AVB-bd.gifFigure 2. Example High Level AVB Network

    An AVB network consists of three types of components:

    1. AV Bridges. An AV Bridge is a relay device that conforms to IEEE 802.1BA. It acts as a switch that receives and forwards IEEE 802.1BA compliant data to the destination device.
    2. End stations. An end station can be a Talker, Listener, or both. A Talker is an end station that is the source, transmitter or producer of a stream. A Listener is an end station that is the destination, receiver or consumer of a stream.
    3. Ethernet LANs (Local Area Network). Individual LANs interconnect the Bridges, Talkers and Listeners.

    To understand more about the AVB end stations see Section 3.