ASRC RAMP MAX Override option in ADAU1466 Processor

KS2021 Question

Apr 8, 2024 00:00

Hi Team,

I have a query in 'ASRC RAMPMAX OVR' Configuration enabling in ADAU1466 processor-based code. Please support.

While 'ASRC RAMPMAX OVR' Configuration is enabled and value set as '-12', around -2dB differences is observed between Input and Output audio. Please confirm whether this is expected.

Sigma Studio Version: 4.5

Hardware: Eval-ADAU1466Z

Audio Signal Processors

Datasheet/Specs

SigmaDSP Audio Processors

SigmaStudio 4.5

adau1466

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Harishgowtham Reply

Apr 9, 2024 00:00

Hello KS2021,

Below is a 16-bit register but only 11 bits can be used, and 5 bits are reserved. This can hold values from 0 to 2047.

2047 is the maximum, when you set that, no reduction will be there in the signal. 0 is the minimum, if you set it, it will mute the signal.

The register you mentioned above is an overriding register. If you enable it, it will override all the ASRCx RAMPMAX register.

If I override,

Though the individual ASRC RAMPMAX register values didn't change, the override register overrides it with a value being set.

If I set the value -12 in the override register and read it like above. I got 0xE8B (note that this is a 16-bit register and upper 4 bits are reserved, MSB of valid 12 bits is an enable bit, rest 11 bits sets the value), if I mask that, I will get the value 0x68B (1675). If I set the value 1675 in one of the ASRC RAMPMAX, I will get the same results. Please look below.

So, depends on the value you set, you will get the gain reduction. You can change the values between 0 to 2047 and see how it drops. If you use the override register, it is a Master gain, it will affect all ASRCs.

Regards,

Harish