ADAU1401A initialize sequence

Hi Yabune-san,

The description on page 17 appears to be incorrect. The correct assignments are as follows:

Bit
Set to One

Set to Zero

[4]
Un-mute ADCs
Mute ADCs

[3]
Un-mute DACs
Mute DACs

[2]
Un-mute Core
Mute Core

During the download, SigmaStudio sets bit [2] low to mute the core, then downloads program/parameter data and registers, then sets bit [2] high again. Bits [4] and [3] are not modified.

In practice, the can select which of these three bits they would like to mute and un-mute during the download sequence.

I will make this update to the datasheet.

Dear Brett-san,

Thank you for your supports.

I understood the usage of bit3 and bit4 in DSP CORE CONTROL REGISTER.

But,

At Recomennded program/parameter loading provedure in datasheet P.17,

1st step is mute the ADC and DAC.

But,Sigma Stadio not mute them.

Should we mute the ADC and DAC at 1st step in initial sequence?

And I checked EEPROM data which is used in self-boot.

1st step in ROM data is 0x00, 0x58.

It means that DSP core is mute and ADC and DAC are un-mute.

If we should mute the ADC and DAC in initial sequence,

could you fix the generator of EEPROM data,please?

Best regards,

Takehiro Yabune

BrettG <analog@sgaur.hosted.jivesoftware.com>

2011/04/30 00:03

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ADAU1401A initialize sequence

reply from BrettG in SigmaDSP Processors - View the full discussion

Hi Yabune-san,

The description on page 17 appears to be incorrect. The correct

assignments are as follows:

Bit

Set to One

Set to Zero

Un-mute ADCs

Mute ADCs

Un-mute DACs

Mute DACs

Un-mute Core

Mute Core

During the download, SigmaStudio sets bit low to mute the core, then

downloads program/parameter data and registers, then sets bit high

again. Bits and are not modified.

In practice, the can select which of these three bits they would like to

mute and un-mute during the download sequence.

I will make this update to the datasheet.

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Hi Yabune-san,

The datasheet is basically making the recommendation to "mute audio when downloading program RAM, parameter RAM, and registers." So, there are three possible ways to do that:

Mute the ADCs

Mute the DACs

Mute the DSP core

Depending on the way the system is designed, there may be analog i/o or digital i/o. Muting the ADCs and DACs will ensure that there will be no analog audio going out of the chip. However, that will not guarantee that the digital audio i/os are silent. So, I think the datasheet's recommendation is wrong and needs to be updated.

Muting the DSP core will guarantee that

No analog or digital audio gets in to the DSP

No analog audio is output on the DACs

No digital audio is output on the serial ports

So, muting the DSP core is the best choice, I think. I will update the datasheet so instead of saying "Mute the ADCs and DACs" it will say "Mute the DSP core."

日本のお客さんの場合に、何かデータシートの間違いがあれば、開発が進めないケースが多いですね。だから、私は出来るだけ速くデータシートを改めます。

Dear Brett-san,

Thank you very much!!

Best regards,

Takehiro Yabune