Audio Muting; Audio Mute Configuration - Analog Devices ADV7850 Hardware Manual

audio_channel_mode, Addr 68 (HDMI), Address 0x07[6] (Read Only)
This readback flags stereo or multichannel audio packets. Note that stereo packets may carry compressed multichannel audio.
Function
audio_channel_mode
0 
1

7.31 AUDIO MUTING

The ADV7850 integrates an advanced audio mute function that is designed to remove all extraneous noise and pops from a 2-channel L-
PCM audio stream at sample frequencies up to 192 kHz. The audio mute controller takes in event detection signals that can be used to
determine when an audio mute is needed. The controller generates a mute signal to the audio block and a coast signal to the digital PLL
generating the audio clock.

Audio Mute Configuration

7.31.1
The ADV7850 can be configured to automatically mute an L-PCM audio stream when selectable mute conditions occur. The audio
muting is configured as follows:
• Set the audio muting speed via audio_mute_speed[4:0].
•
Set not_auto_unmute

Set not_auto_unmute
selected mute conditions have become inactive.

Set not_auto_unmute to 1 if the audio must be unmuted manually (for example, by an external controller) when all
selected mute conditions have become inactive.

Select the mute conditions that trigger an audio mute (refer to
• Select the Audio PLL coast conditions (refer to Section 7.25.4).
• Set wait_unmute[2:0]
conditions have become inactive.
The ADV7850 internally unmutes the audio if the following three conditions (listed in order of priority) are met:
• Mute conditions are inactive
• not_auto_unmute
•
Audio unmute counter has finished counting down or is disabled
Notes:
• For the best audio muting performance, set AUDIO_MUTE_SPEED to 1.
•
Both Table 13 and
registers that convey information related to their corresponding audio mute masks or coast masks.
• The ADV7850 also mutes the DSD stream when one of the selected mute conditions occurs (refer to
DSD mute pattern 0101010101... A DSD decoder receiving this stream outputs a 0 V mean analog stream.
• The ADV7850 never mutes the audio data when it receives an audio sample packet with compressed audio data or HBR packets.
mute_audio, Addr 68 (HDMI), Address 0x1A[4]
This control is used to force an internal mute independently of the mute mask conditions.
Function
mute_audio
0 
1
Rev. A May 2012
Description
Stereo audio (may be compressed multichannel)
Multichannel uncompressed audio detected (3-8 channels)
as follows:
to 0 if the audio must be unmuted automatically after a delay set in
to configure the audio counter that triggers the audio unmute when it has timed out after all selected mute
is set to 0
Table 24 provide a column with the heading 'Corresponding Status Registers(s)' . This column lists the status
Description
Audio in normal operation
Force audio mute
Table 24).
192
ADV7850
wait_unmute[2:0] after all
Table 24) by outputting the