EIA STANDARD
A DTV Profile for Uncompressed
High Speed Digital Interfaces
EIA/CEA-861-B
(Revision of EIA/CEA-861-A)

861B is fully backward compatible with 861A. It assumes the same functionality at the
physical/link layers as is required to gain the extra functionality of 861A. For example, it
relies on the ability of the source device to transmit CEA InfoPackets and the ability of
the DTV Monitor to receive them. It supports the transmission of digital audio if the
specific interface supports digital audio. Like 861A, 861B is fully backward compatible
with 861 and requires the use of a backward compatible version of the interface used
with 861 (e.g., DVI1.0). Source boxes designed to 861A or 861B will be able to supply
video to an 861 compliant DTV Monitor and source boxes designed to 861 will be able
to supply video to an 861A or 861B compliant DTV Monitor. In both of these cases, the
system would have the same functionality as if both devices were only 861 devices.
However, if both devices are designed to meet this full standard (EIA/CEA-861B), then
the enhancements added in this standard and 861A would be available (e.g., aspect
ratio information, active format information, native format information, etc.). For this to
work, the versions of DVI or Open_LDI that are used with EIA/CEA-861B must have
enhancements to carry CEA InfoPackets, but must also be backward compatible
(source and destination) with the versions of those specifications referenced in
EIA/CEA-861.