Forums

Soundbite (DSP56371) and 192kHz sampling

Started by "petr.sh111" August 2, 2009
Hi,
I have bought recently a Symphony Soundbite Development kit. It has onboard DSP56371, AK4584 as the I2S clock master and ADC/DACs AK4556.

I need 192kHz sampling rate for the analog audio inputs. I have used Freescale's sample C-application that enables passthrough for all channels. It works fine at 48, 64, 96 kHz sampling frequencies. I have problems enabling 192kHz: I can see the input 1kHz 2.4v sine-wave is distorted/garbaged completely.

For 192kHz I changed the configuration for AK4584: the quad-mode is enabled and 192kHz clock is configured (reg0x9=0xAA (tried 0xEE as well with the same result), reg0x2=0xE). I can see that LRCLK is actually 192kHz, but the original sine-wave is corrupted on the analog output.

Could you please advise the way to enable Soundbite kit for 192kHz sampling?
Hi,
Please note that AK4584 does not support 192K ADC but it do can generate
LRCLK/BCLK clock for AK4556.

From the features list of AK4584 data sheet(
http://datasheet.digchip.com/025/025-00607-0-AK4584.pdf) we can see that
this codec
1. Support 24bit 2ch 96K ADC, 192K DIR
2. Support 24bit 2ch 192K DAC, 192K DIT

In order to support 192K, we should use 128fs mode and quad speed mode as
well. In the section "System clock", that mentioned "The ADC is powered down
during quad speed mode".

AK4556 clock has been configured as slave move with CKS3:0 = 0100. It should
support fs2K.

Hope these information can do help to you.

--
Best Regards.

Johnny Chen
2009/8/2 petr.sh111

> Hi,
> I have bought recently a Symphony Soundbite Development kit. It has onboard
> DSP56371, AK4584 as the I2S clock master and ADC/DACs AK4556.
>
> I need 192kHz sampling rate for the analog audio inputs. I have used
> Freescale's sample C-application that enables passthrough for all channels.
> It works fine at 48, 64, 96 kHz sampling frequencies. I have problems
> enabling 192kHz: I can see the input 1kHz 2.4v sine-wave is
> distorted/garbaged completely.
>
> For 192kHz I changed the configuration for AK4584: the quad-mode is enabled
> and 192kHz clock is configured (reg0x9=0xAA (tried 0xEE as well with the
> same result), reg0x2=0xE). I can see that LRCLK is actually 192kHz, but the
> original sine-wave is corrupted on the analog output.
>
> Could you please advise the way to enable Soundbite kit for 192kHz
> sampling?
>
>
>
Hi,

Please note that AK4584 does not support 192K ADC but it do can generate LRCLK/BCLK clock for AK4556.

From the features list of AK4584 data sheet(http://datasheet.digchip.com/025/025-00607-0-AK4584.pdf) we can see that this codec
1. Support 24bit 2ch 96K ADC, 192K DIR
2. Support 24bit 2ch 192K DAC, 192K DIT

In order to support 192K, we should use 128fs mode and quad speed mode as well. In the section "System clock", that mentioned "The ADC is powered down during quad speed mode".

AK4556 clock has been configured as slave mode with CKS3:0 = 0100. It should support fs2K.

Hope these information can do help to you.

Johnny
Hi,
>I have bought recently a Symphony Soundbite Development kit. It has onboard DSP56371, AK4584 as the I2S clock master and ADC/DACs AK4556.
>
>I need 192kHz sampling rate for the analog audio inputs. I have used Freescale's sample C-application that enables passthrough for all channels. It works fine at 48, 64, 96 kHz sampling frequencies. I have problems enabling 192kHz: I can see the input 1kHz 2.4v sine-wave is distorted/garbaged completely.
>
>For 192kHz I changed the configuration for AK4584: the quad-mode is enabled and 192kHz clock is configured (reg0x9=0xAA (tried 0xEE as well with the same result), reg0x2=0xE). I can see that LRCLK is actually 192kHz, but the original sine-wave is corrupted on the analog output.
>
>Could you please advise the way to enable Soundbite kit for 192kHz sampling?
Hi,

the AK4584 supports 96kHz for the ADC only, see:
http://www.asahi-kasei.co.jp/akm/en/product/ak4584/ak4584_f00e.pdf ,
the AK4556 supports all sample frequencies up to 192kHz, see:
http://www.asahi-kasei.co.jp/akm/en/product/ak4556/ak4556_f00e.pdf .

I assumed that you may use the I/Os of those codecs to get the 192kHz sample rate, even if the AK4584 does not support this for the input. I experiented your configurations, even the channels 3 to 8 didn't support 192kHz (see result below). The digital I/Os cannot be used with this sample rate as well since the optical inputs do not lock to this frequency (176.4kHz works almost, but loses sync too often). A replacement of the optical I/Os be electrical SP/DIFs would help to overcome this.

Yes, indeed, configuring register 0x09 with 0xAA is the proper adjustment(0xEE seems to be wrong to me) and Register 0x02 with 0xE is the way to go but the signal is sampled with 48kHz(!) then. This can be observed by applying a 24kHz sine signal to the inputs, it will 'disappear' since this is the Nyquist frequency.

So the 192kHz capacity seems to be a marketing figure... For the moment I can see no measure to use the Soundbite board for 192kHz sample rate without modifications.

Regards

Christian

Hi,
>I have bought recently a Symphony Soundbite Development kit. It has onboard DSP56371, AK4584 as the I2S clock master and ADC/DACs AK4556.
>
>I need 192kHz sampling rate for the analog audio inputs. I have used Freescale's sample C-application that enables passthrough for all channels. It works fine at 48, 64, 96 kHz sampling frequencies. I have problems enabling 192kHz: I can see the input 1kHz 2.4v sine-wave is distorted/garbaged completely.
>
>For 192kHz I changed the configuration for AK4584: the quad-mode is enabled and 192kHz clock is configured (reg0x9=0xAA (tried 0xEE as well with the same result), reg0x2=0xE). I can see that LRCLK is actually 192kHz, but the original sine-wave is corrupted on the analog output.
>
>Could you please advise the way to enable Soundbite kit for 192kHz sampling?
AK4584 can generate 192K clock although it has no output from SDTO.
The clocks from 4584 can drive other three AK4556 ADCs to work at 192K
SR.
Routing input signal into other three AK4556 ADCs, modify your
passthrough code as well, channel 3~8 should have output.
2009/8/5, c...@gmx.de :
> Hi,
>
> the AK4584 supports 96kHz for the ADC only, see:
> http://www.asahi-kasei.co.jp/akm/en/product/ak4584/ak4584_f00e.pdf ,
> the AK4556 supports all sample frequencies up to 192kHz, see:
> http://www.asahi-kasei.co.jp/akm/en/product/ak4556/ak4556_f00e.pdf .
>
> I assumed that you may use the I/Os of those codecs to get the 192kHz sample
> rate, even if the AK4584 does not support this for the input. I experiented
> your configurations, even the channels 3 to 8 didn't support 192kHz (see
> result below). The digital I/Os cannot be used with this sample rate as well
> since the optical inputs do not lock to this frequency (176.4kHz works
> almost, but loses sync too often). A replacement of the optical I/Os be
> electrical SP/DIFs would help to overcome this.
>
> Yes, indeed, configuring register 0x09 with 0xAA is the proper
> adjustment(0xEE seems to be wrong to me) and Register 0x02 with 0xE is the
> way to go but the signal is sampled with 48kHz(!) then. This can be observed
> by applying a 24kHz sine signal to the inputs, it will 'disappear' since
> this is the Nyquist frequency.
>
> So the 192kHz capacity seems to be a marketing figure... For the moment I
> can see no measure to use the Soundbite board for 192kHz sample rate without
> modifications.
>
> Regards
>
> Christian
>
> Hi,
>>I have bought recently a Symphony Soundbite Development kit. It has onboard
>> DSP56371, AK4584 as the I2S clock master and ADC/DACs AK4556.
>>
>>I need 192kHz sampling rate for the analog audio inputs. I have used
>> Freescale's sample C-application that enables passthrough for all
>> channels. It works fine at 48, 64, 96 kHz sampling frequencies. I have
>> problems enabling 192kHz: I can see the input 1kHz 2.4v sine-wave is
>> distorted/garbaged completely.
>>
>>For 192kHz I changed the configuration for AK4584: the quad-mode is enabled
>> and 192kHz clock is configured (reg0x9=0xAA (tried 0xEE as well with the
>> same result), reg0x2=0xE). I can see that LRCLK is actually 192kHz, but
>> the original sine-wave is corrupted on the analog output.
>>
>>Could you please advise the way to enable Soundbite kit for 192kHz
>> sampling?
>>
>

--
Best Regards.

Johnny Chen
Hi Jonny,

this is exactly what I did, the result was a sample rate of 48kHz for I/Os 3 to 8 with I/Os 1 and 2 'muted', i.e. no signal. I couldn't help soving this issue.

Regards

Christian

-------- Original-Nachricht --------
> Datum: Thu, 6 Aug 2009 17:52:15 +0800
> Von: Johnny Chen
> An: c...@gmx.de
> CC: m...
> Betreff: Re: [motoroladsp] Re: Soundbite (DSP56371) and 192kHz sampling

> AK4584 can generate 192K clock although it has no output from SDTO.
> The clocks from 4584 can drive other three AK4556 ADCs to work at 192K
> SR.
> Routing input signal into other three AK4556 ADCs, modify your
> passthrough code as well, channel 3~8 should have output.
> 2009/8/5, c...@gmx.de :
> > Hi,
> >
> > the AK4584 supports 96kHz for the ADC only, see:
> > http://www.asahi-kasei.co.jp/akm/en/product/ak4584/ak4584_f00e.pdf ,
> > the AK4556 supports all sample frequencies up to 192kHz, see:
> > http://www.asahi-kasei.co.jp/akm/en/product/ak4556/ak4556_f00e.pdf .
> >
> > I assumed that you may use the I/Os of those codecs to get the 192kHz
> sample
> > rate, even if the AK4584 does not support this for the input. I
> experiented
> > your configurations, even the channels 3 to 8 didn't support 192kHz (see
> > result below). The digital I/Os cannot be used with this sample rate as
> well
> > since the optical inputs do not lock to this frequency (176.4kHz works
> > almost, but loses sync too often). A replacement of the optical I/Os be
> > electrical SP/DIFs would help to overcome this.
> >
> > Yes, indeed, configuring register 0x09 with 0xAA is the proper
> > adjustment(0xEE seems to be wrong to me) and Register 0x02 with 0xE is
> the
> > way to go but the signal is sampled with 48kHz(!) then. This can be
> observed
> > by applying a 24kHz sine signal to the inputs, it will 'disappear' since
> > this is the Nyquist frequency.
> >
> > So the 192kHz capacity seems to be a marketing figure... For the moment
> I
> > can see no measure to use the Soundbite board for 192kHz sample rate
> without
> > modifications.
> >
> > Regards
> >
> > Christian
> >
> > Hi,
> >>I have bought recently a Symphony Soundbite Development kit. It has
> onboard
> >> DSP56371, AK4584 as the I2S clock master and ADC/DACs AK4556.
> >>
> >>I need 192kHz sampling rate for the analog audio inputs. I have used
> >> Freescale's sample C-application that enables passthrough for all
> >> channels. It works fine at 48, 64, 96 kHz sampling frequencies. I have
> >> problems enabling 192kHz: I can see the input 1kHz 2.4v sine-wave is
> >> distorted/garbaged completely.
> >>
> >>For 192kHz I changed the configuration for AK4584: the quad-mode is
> enabled
> >> and 192kHz clock is configured (reg0x9=0xAA (tried 0xEE as well with
> the
> >> same result), reg0x2=0xE). I can see that LRCLK is actually 192kHz, but
> >> the original sine-wave is corrupted on the analog output.
> >>
> >>Could you please advise the way to enable Soundbite kit for 192kHz
> >> sampling?
> >>
> >>
> >
> --
> Best Regards.
>
> Johnny Chen
Hi Christian,

I have tried that on my two Soundbite boards.
One is ok to generate 192k clock and get proper output for I/Os 3 to 8 with
I/Os 1 and 2 'muted'.
Another one only generate 44.1K clock. I think the second board must have
something wrong with codec. I didn't do further test on that. I think your
board may have the same problem. Perhaps we can read back all register
setting from codec to double check it.

--
Best Regards.

Johnny Chen

2009/8/6 Christian Langen

> Hi Jonny,
>
> this is exactly what I did, the result was a sample rate of 48kHz for I/Os
> 3 to 8 with I/Os 1 and 2 'muted', i.e. no signal. I couldn't help soving
> this issue.
>
> Regards
>
> Christian
>
> -------- Original-Nachricht --------
> > Datum: Thu, 6 Aug 2009 17:52:15 +0800
> > Von: Johnny Chen
> > An: c...@gmx.de
> > CC: m...
> > Betreff: Re: [motoroladsp] Re: Soundbite (DSP56371) and 192kHz sampling
>
> > AK4584 can generate 192K clock although it has no output from SDTO.
> > The clocks from 4584 can drive other three AK4556 ADCs to work at 192K
> > SR.
> > Routing input signal into other three AK4556 ADCs, modify your
> > passthrough code as well, channel 3~8 should have output.
> >