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TLV320AIC3254: AIC3254 AGC Volume Control

Trevor Hsu

Genius 4565 points

Part Number: TLV320AIC3254

Hi ,

We checked the TLV320AIC3254 Application Reference Guide, the PGA gain is controlled by the AGC and cannot be controlled by ourselves..

Can you help check which of the following registers are invalid when AGC is enabled?

Page 0 / Register 83: Left ADC Channel Volume Control Register - 0x00 / 0x53 (P0_R83)
Page 0 / Register 84: Right ADC Channel Volume Control Register - 0x00 / 0x54

Page 1 / Register 59: Left MICPGA Volume Control Register - 0x01 / 0x3B (P1_R59)
Page 1 / Register 60: Right MICPGA Volume Control Register - 0x01 / 0x3C (P1_R60)

Thanks.

BR

Trevor

over 3 years ago

0 pdjuandi over 3 years ago

TI__Mastermind 29755 points

Hi,

If you enable the AGC, the built in AGC hardware will control the PGA gain automatically as its algorithm will adjust to meet the requirement accordingly.

On the volume control registers, you should be able to control even AGC is enabled - I have verified this on EVM.

AIC3254 AGC On Volume Control.pptx

0 Trevor Hsu over 3 years ago in reply to pdjuandi

Genius 4565 points

Hi pdjuandi,

Thanks for your help, could you help to check the following thread:

TLV320AIC3120: AGC and digital volume control - Audio forum - Audio - TI E2E support forums

Regarding this thread, it seems that the volume can only be controlled by the DSP when the AGC is enabled.

BR

Trevor

0 pdjuandi over 3 years ago in reply to Trevor Hsu

TI__Mastermind 29755 points

Hi,

I think he was referring to controlling this through DSP not necessary meant only works with DSP.

Are you not able to write the volume register at all when AGC is enabled?

From my testing on EVM I can change that.

0 Trevor Hsu over 3 years ago in reply to pdjuandi

Genius 4565 points

Hi pdjuandi,

We know we can write this volume register, but the output level didn't change.

In the above thread, it suggests that the volume can only be controlled by the DSP when the AGC is enabled.

BR

Trevor

0 pdjuandi over 3 years ago in reply to Trevor Hsu

TI__Mastermind 29755 points

OK good that's what I was trying to understand, it might be the case but will check out on EVM and let you know.

+1 pdjuandi over 3 years ago in reply to pdjuandi

TI__Mastermind 29755 points

Hi,

It's confirmed and tested on EVM the volume can't be adjusted when AGC is enabled.

See attached ppt.

AIC3254 AGC On & Volume Control.pptx

0 Trevor Hsu over 3 years ago in reply to pdjuandi

Genius 4565 points

Thanks for your help.

BR

Trevor

0 pdjuandi over 3 years ago in reply to Trevor Hsu

TI__Mastermind 29755 points

You are welcome.