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Porting USB Audio 2.0 to XU208 - problem with DSD
Posted: Tue May 02, 2017 6:08 pm
by AlexAdvice
Hi, I've successfully ported the Reference Design to XU208, now PCM works fine, but I see the problem with DSD.
I got the right BCLK frequency and 2 bitstreams at LRCLK and SDATA. But the data if only at 1/8 of the time. See attach.
(Sorry, my Agilent scope failed and is at repairing now, so I use the old one w/o USB, and simply make a photo of the screen).
It doesn't matter DSD64 or 128, just the frequency changes.
Also the same thing in DoP or Native DSD.
Re: Porting USB Audio 2.0 to XU208 - problem with DSD
Posted: Thu May 04, 2017 9:46 am
by AlexAdvice
I tried again, and had no success.
Except if data bits missing, I do not see something, hat looking as 0x96969696 - sometimes a see 001100 sequence, which is not possible "0x96".
Re: Porting USB Audio 2.0 to XU208 - problem with DSD
Posted: Thu May 04, 2017 10:19 am
by infiniteimprobability
That is odd.. What changes have you made to audio.xc? We know that our DSD codebase is solid and works (multiple high quality dacs based on it eg
https://www.xmos.com/news/press/17176) so there must be a change to this somehow..
You say that the DSD clock is the expected frequency for each case? 2.8224MHz/ 5.6448MHz ?
Is the proportion of time that DSD data is active the same for DSD64 and DSD128? If the proportion of time that data is active is greater at higher rates, I'm wondering if your DSD dac ports are not properly connected to p_dsd_clk and are being emptied too quickly.. Check that the right arguments are being passed to ConfigAudioPorts()
Re: Porting USB Audio 2.0 to XU208 - problem with DSD
Posted: Thu May 04, 2017 2:08 pm
by AlexAdvice
infiniteimprobability wrote:That is odd.. What changes have you made to audio.xc?
Nothing!
Just add:
Code: Select all
#ifdef U208_ONLY
set_core_high_priority_on();
#endif
at the main.xc
All other chahnges were made in customdefines.h, .xn and Makefile
infiniteimprobability wrote:
We know that our DSD codebase is solid and works (multiple high quality dacs based on it eg
https://www.xmos.com/news/press/17176) so there must be a change to this somehow..
I know - with 6.6.0rc5 it works fine at XS1-L6A, but now I'm working with 6.16.2 and XUF208
infiniteimprobability wrote:
You say that the DSD clock is the expected frequency for each case? 2.8224MHz/ 5.6448MHz ?
Is the proportion of time that DSD data is active the same for DSD64 and DSD128?
Yes, BCLK is 2.8 for DSD64, 5.6 for DSD128 and 11.2 for DSD256.
The proportion remains the same - 1/8
infiniteimprobability wrote:
If the proportion of time that data is active is greater at higher rates, I'm wondering if your DSD dac ports are not properly connected to p_dsd_clk and are being emptied too quickly.. Check that the right arguments are being passed to ConfigAudioPorts()
I connected the ports in .xn file, maybe i is not enough?
Can you check my files (in attach)?
Re: Porting USB Audio 2.0 to XU208 - problem with DSD
Posted: Fri May 05, 2017 12:48 pm
by AlexAdvice
The proportion remains the same - 1/8
I was not correct.
The proportion (duty cycle) changes.
Active packet is always 32*BCLK, but the duty cycle (packet time / packet period) are:
DSD64: 1/8
DSD128: 1/4
DSD256: 1/2 (i.e. - data is just half of the time)
I have no idea what to do.
Re: Porting USB Audio 2.0 to XU208 - problem with DSD
Posted: Tue May 09, 2017 9:06 am
by Ross
I believe there is an issue in the latest release on xCORE-200 with regards to DSD clock generation. The code setups of the HW clock divider in xCORE-200 but the normal clock outputs also remain in place . I believe these outputs need removing for xCORE-200 (and the divide tweaked for DSD operation)
Re: Porting USB Audio 2.0 to XU208 - problem with DSD
Posted: Tue May 09, 2017 11:36 am
by AlexAdvice
Hi Ross,
thank you very much for your answer, I do not think I will able to do this without your help :(
But, I will try.
Thank you again.
P.S. I do not believe that nobody used XU(F)208 with Audio Reference Design, including DSD and have no solution.
Re: Porting USB Audio 2.0 to XU208 - problem with DSD
Posted: Wed May 10, 2017 7:19 pm
by pasnew
Hi,
I had this problem, here is the solution, however DSD256 and 512 still not work correctly.
http://www.xcore.com/viewtopic.php?f=26&t=5010
It's ridiculous that for over one year the latest software doesn't work correctly for 200 series !
Re: Porting USB Audio 2.0 to XU208 - problem with DSD
Posted: Thu May 11, 2017 7:45 am
by AlexAdvice
[quote had this problem, here is the solution, however DSD256 and 512 still not work correctly.[/quote]
Hi pasnew, thanks for you reply and link to the topic, I will try.
Don''t know why I missed this topic.
[quote]It's ridiculous that for over one year the latest software doesn't work correctly for 200 series ! [ /quote]
Also why AN1027 does not have corresponding source - there were many problems after copy-paste from pdf and was not clear where are the mistakes - or typo in source on not.
We have some products, based on XS1-L6, which we want to make new versions, based on XU(F)208.
Because we have some problem - where to buy XS1-L6. We do not have mass production, just few dozen per year, so we use Digikey and Farnell, but they have very long lead time for this chip.
We do not in hurry, some our products does not required DSD were successfully transferred to XUF208, other waiting for the solution.
Re: Porting USB Audio 2.0 to XU208 - problem with DSD
Posted: Thu May 11, 2017 12:07 pm
by mon2