AVB software architecture on ARM Cortex SOCs
Summary: Traditional clocking synchronization in networked A/V systems is done via elaborate means. In the automotive sector, the clock synchronization of displays and multi-channel audio in an infotainment platform is implemented using MOST, which is an isochronous environment. In the Pro-A/V area, the displays are synchronized through a combination of separate master clock control link and fixed delay compensation depending on the length of the control link. Synchronization thus has been a tedious and time consuming exercise. Standard Ethernet does not provide QoS and it is an asynchronous environment, although topologies exist to provide it today.
The Ethernet AVB Protocol (IEEE1722+IEEE1588 or 802.1AS) in one such standard that formally brings a QoS and synchronization implementation to Ethernet. By providing global time synchronization mechanism combined with a protocol of prioritization of streams as they pass through switches, Ethernet AVB offers an Isochronous environment similar to that of the MOST bus. Ethernet AVB protocol allows widespread proliferation of Ethernet standard in Automotive, Pro-AV and Pro-Audio systems.
Examples of Ethernet AVB application are:
1) Automotive ADAS in surround camera architecture
2) Automotive Infotainment End points
3) Pro A/V video wall projection system and
4) Multichannel Sound system for Automotive, Studio Environments.