The General Control Packet (GCP) is primarily handled by the hardware but is also passed to the software so that the information can be used at the system application level.
The General Control Packet is automatically generated by the HDMI 1.4/2.0 TX Subsystem according to the video stream and sent out within 384 clocks after vsync. Four API functions are defined to set or clear the AVMUTE field as per their system application requirement.
void XV_HdmiTxSs_SetGcpAvmuteBit(XV_HdmiTxSs *InstancePtr);
void XV_HdmiTxSs_ClearGcpAvmuteBit(XV_HdmiTxSs *InstancePtr);
void XV_HdmiTxSs_SetGcpClearAvmuteBit(XV_HdmiTxSs *InstancePtr);
void XV_HdmiTxSs_ClearGcpClearAvmuteBit(XV_HdmiTxSs *InstancePtr);