Can someone help me understand the volume/gain architecture of this platform.
Discussion:
On the spec page 4 shows VOL for the 2nd AGL and Vol1/Vol2 for the 1st AGL. I presume this is MVOL, VOL1 and VOL2 from the registers 0x07, 0x08, 0x09 from page 42.
When DRCs are off or if I use 1 DRC, the volume behaves as expected, master volume controls all, Vol1 -> L Vol2 -> R. When using the DRC in series mode, Vol adds extra gain to the 2nd DRC while Vol1, Vol2 behave as shown on page 4. muting Vol1 and vol2, works as expected. Now muting Vol (aka MVOL) it will mute the complete audio chain.
When in parallel DRC mode, Vol seems to change the master volume of the system although you would only expect it to change the gain of the 2nd DRC only.
Question(s):
1. So the question, where exactly is the volume controls in the signal chain?
2. On page 4, the prescale register 0x57 is shown after the audio processing, How can the prescale be after the processing? I would expect it prior to the first biquad.
3. Is there a document describing any designed or built in headroom for the amplifier processing?
