I am using ADV7611 for both uncompressed (PCM) and compressed (AC3) audio via the i2s pins.
I can process audio in both modes by checking the CS_DATA PCM mode i2c register and then handling the stream with the correct codec.
However, I have an issue when the stream changes from PCM to AC3. Since the i2c reads are not very fast, I get some compressed audio which is interpreted as PCM. This causes artifacts.
From the documentation, it seems to indicate that I can use the automatic MUTE on adv7611 to resolve this.
My plan was to SET the MT_MSK_COMPRS_AUD bit while in PCM audio mode.
Thus when the stream switches to AC3 it would automatically mute the audio.
Once my application detects this it would set MT_MSK_COMPRS_AUD to 0 which should unmute the audio and we can proceed without the transition artifact.
We have implemented this but the MT_MSK_COMPRS_AUD bit does not mute the compressed audio.
The other registers are set according to the recommendations in UG-180 (audio mute section).
Is there are restriction on WHEN the MT_MSK_COMPRS_AUD bit can be changed to still be effective?