Asynchronous I2S FIFO project, an ultimate weapon to fight the jitter - Page 2 - diyAudio
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Old 24th July 2011, 05:07 PM   #11
Irakli is offline Irakli  United States
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Very nice job indeed! I wish you published more details.
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Old 24th July 2011, 06:22 PM   #12
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Quote:
Originally Posted by qusp View Post
never mind, i just spotted the connector on the board, not the 6ghz micro coax smd type i was thinking you might use
Hi Qusp. Thank you for interesting. I figured out what you were talking about. That's very good point. It should be like this: Digi-Key - J983CT-ND (Manufacturer - 128-0711-201) I may try it later on.
what I'm useing right now for the mclk on the I2S FIFO board is the SMA RF connector. Ian
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Old 24th July 2011, 06:25 PM   #13
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Originally Posted by Irakli View Post
Very nice job indeed! I wish you published more details.
Thanks Irakli, I will. Have a nice weekend. Ian
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Old 24th July 2011, 06:44 PM   #14
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Best of luck with the project - I'm subscribing to this thread!
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Old 25th July 2011, 02:55 AM   #15
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Best of luck with the project - I'm subscribing to this thread!
Thank you so much Woodturner-fran. I'm busy testing the boards. I'll update it as soon as possible. Regards, Ian
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Old 25th July 2011, 07:13 AM   #16
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wow! Ian that is really impressiv how fast this is all going on! I am so surprised and happy about that!) All the best, really excited! Best regards, Florian
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Old 25th July 2011, 08:07 AM   #17
qusp is offline qusp  Australia
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Originally Posted by iancanada View Post
Hi Qusp. Thank you for interesting. I figured out what you were talking about. That's very good point. It should be like this: Digi-Key - J983CT-ND (Manufacturer - 128-0711-201) I may try it later on.
what I'm useing right now for the mclk on the I2S FIFO board is the SMA RF connector. Ian
Hey Ian, yeah sorry i should have linked it and i forgot the dot in w.fl, its that type, but the one i'm using is a touch more upmarket, its made by hirose and comes available with double shielded mini coax cables, it looks to be the same, or at least similar connection standard as the one you linked, but its a bit pricier and does seem, or at least looks higher quality. its also described as ultra low coax smd, so perhaps its lower profile.

they really are excellent and handy little connectors, i have also used them just recently for sense/feedback connections for low noise regulators to power my portable dac.

see them on my ackodac AKD12P below, makes for really neat compact connections. they were just hooked up randomly for this pic a while ago now before i stuffed the boards
Attached Images
File Type: jpg PTFE AKD12P Teh SEX small.jpg (238.2 KB, 3585 views)

Last edited by qusp; 25th July 2011 at 08:10 AM.
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Old 26th July 2011, 02:24 AM   #18
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Default Functional test

Functional test was done. Everything seems OK, so far so good. The actual timing is almost as same as the simulation result I did a month ago. Some bugs in the Verilog source code have been fixed. Little bit modification on PCB will be shown at the next version. Here are some details.
1. I2S Timing test
44.1Khz 16bit: PASS
48Khz 16bit: PASS
88.2Khz 24bit: PASS
96Khz 24bit: PASS
192Khz 24bit: PASS
2. Bit perfect test
2^32 times 32bit data comparison, no error found
3. I2S FIFO delay test
0.89s for 44.1K I2S stream between input and output with FIFO depth around half full (could you put up with it?)
The attached pictures are the testing result from a logic analyzer. Just for reference. It shows very clear that the input sck and ws has nothing to do with the output sck and ws on timing.
The next step gonna be the playing test.
Attached Images
File Type: jpg FifoTimingFs44.1K16Bit.JPG (114.5 KB, 3394 views)
File Type: jpg FifoTimingFs96K24Bit.JPG (119.4 KB, 3196 views)
File Type: jpg I2sFifoDelayFs44.1K.JPG (88.1 KB, 3100 views)

Last edited by iancanada; 26th July 2011 at 02:27 AM.
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Old 26th July 2011, 06:25 AM   #19
qusp is offline qusp  Australia
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looks good, though that delay, if needed any time you switched tracks in an album is a bit annoying, though i guess unavoidable?
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Old 26th July 2011, 07:34 PM   #20
guido is offline guido  Netherlands
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Originally Posted by iancanada View Post
I2S FIFO delay test 0.89s for 44.1K I2S stream between input and output with FIFO depth around half full (could you put up with it?)
Actually yes. But why not more memory to increase the 1486 seconds?
Think anyone can live with more delay.

And with highres material, i guess the 1486 seconds is a lot less...
Do you detect "silences" between songs and allow the fifo to go to half full again (remove/add some silence)?

But indeed interesting. Seems easier than trying to build an extra pll
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