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• Hybrid
• IP

Architecture Overview

HDMI-CEC Profiles supported in RDK

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How HDMI-CEC Works in RDK

Application API Specification

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• The Library APIs allows application to contrl how the CEC stack operates, such as adding logical address to the stack.

The Host interface allows libCEC implementation to interact with the host environment. Such interaction includes monitoring of the Power State change, the HDMI HotPlug events, or API to change the Host State. The Host Interface is delivered as a run-time plugin to the libCEC stack. This allows the CEC stack to run in any devices that implements the Host Interface.

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The relation between Application, Connection and CEC-Bus is described in the figure.

CEC Daemon

• This daemon receives Raw Bytes from the SoC Driver and dispatches them into IARM Bus via CecIARMMgr, it also receives Raw Bytes from IARM Bus and send to the SoC Driver. It controls the only access point to the physical HDMI CEC Bus.

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In essence, there is only one physical CEC bus on a system. However, with the help of Connection, Logical CEC-Bus, and IARM-Bus, the CEC library can converge the CEC traffic from different Connections and Logical Buses before forwarding them to the single physical bus. This is illustrated by the diagram below.

In this diagram there are two applications (Receiver and CECDevMgr). Since both applications can only access the underlying physical CEC Bus via Connection API, they have no knowledge how the message are eventually delivered to the Physical Bus.

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