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No audio in Ad9889b

Hi, Gal

We are passing video and audio in I2S: sampling freq - 48k, Word length - 16bits, via the next 4 lines MCLK, SCK, LRCLK , I2S-0. The signals in the lines are described in the attached files scope_1.bmp and scope_2.bmp. As a result we received in the HDMI output - Screen good video but no audio. We connected the HDMI output to audio analyzer and we received a result that described in the attached file DSCN0570.JPG. I attached also my dump registers.

Register #0 => 0
Register #1 => 0
Register #2 => 18
Register #3 => 0
Register #4 => 0
Register #5 => b
Register #6 => e7
Register #7 => 0
Register #8 => 0
Register #9 => 0
Register #a => 0
Register #b => e
Register #c => 6
Register #d => 10
Register #e => 1
Register #f => 13
Register #10 => 25
Register #11 => 37
Register #12 => 0
Register #13 => 0
Register #14 => 0
Register #15 => 24
Register #16 => 74
Register #17 => 68
Register #18 => 8
Register #19 => 0
Register #1a => 0
Register #1b => 0
Register #1c => 0
Register #1d => 0
Register #1e => 0
Register #1f => 0
Register #20 => 0
Register #21 => 0
Register #22 => 8
Register #23 => 0
Register #24 => 0
Register #25 => 0
Register #26 => 0
Register #27 => 0
Register #28 => 0
Register #29 => 0
Register #2a => 0
Register #2b => 0
Register #2c => 8
Register #2d => 0
Register #2e => 0
Register #2f => 0
Register #30 => 1b
Register #31 => 82
Register #32 => 80
Register #33 => 14
Register #34 => 5
Register #35 => 40
Register #36 => d9
Register #37 => a
Register #38 => 0
Register #39 => 2d
Register #3a => 0
Register #3b => 81
Register #3c => 4
Register #3d => 0
Register #3e => 0
Register #3f => 0
Register #40 => 0
Register #41 => 10
Register #42 => e0
Register #43 => 7e
Register #44 => 78
Register #45 => 60
Register #46 => 4
Register #47 => 80
Register #48 => 0
Register #49 => 0
Register #4a => 0
Register #4b => 0
Register #4c => 0
Register #4d => 0
Register #4e => 0
Register #4f => 0
Register #50 => 20
Register #51 => 0
Register #52 => 0
Register #53 => 0
Register #54 => 0
Register #55 => 0
Register #56 => 0
Register #57 => 0
Register #58 => 0
Register #59 => 0
Register #5a => 0
Register #5b => 0
Register #5c => 0
Register #5d => 0
Register #5e => 0
Register #5f => 0
Register #60 => 0
Register #61 => 0
Register #62 => 0
Register #63 => 0
Register #64 => 0
Register #65 => 0
Register #66 => 0
Register #67 => 0
Register #68 => 0
Register #69 => 0
Register #6a => 0
Register #6b => 0
Register #6c => 0
Register #6d => 0
Register #6e => 0
Register #6f => 0
Register #70 => 0
Register #71 => 0
Register #72 => 0
Register #73 => 0
Register #74 => 0
Register #75 => 0
Register #76 => 0
Register #77 => 0
Register #78 => 0
Register #79 => 0
Register #7a => 0
Register #7b => 0
Register #7c => 0
Register #7d => 0
Register #7e => 0
Register #7f => 0
Register #80 => 0
Register #81 => 0
Register #82 => 0
Register #83 => 0
Register #84 => 0
Register #85 => 0
Register #86 => 0
Register #87 => 0
Register #88 => 0
Register #89 => 0
Register #8a => 0
Register #8b => 0
Register #8c => 0
Register #8d => 0
Register #8e => 0
Register #8f => 0
Register #90 => 0
Register #91 => 0
Register #92 => 0
Register #93 => 0
Register #94 => 84
Register #95 => 0
Register #96 => 0
Register #97 => 0
Register #98 => 7
Register #99 => 2
Register #9a => 0
Register #9b => 18
Register #9c => 38
Register #9d => 60
Register #9e => 10
Register #9f => 70
Register #a0 => 0
Register #a1 => 38
Register #a2 => 87
Register #a3 => 87
Register #a4 => 8
Register #a5 => 4
Register #a6 => 0
Register #a7 => 0
Register #a8 => 0
Register #a9 => 0
Register #aa => 0
Register #ab => 40
Register #ac => 0
Register #ad => 0
Register #ae => 40
Register #af => 16
Register #b0 => b8
Register #b1 => 24
Register #b2 => 9f
Register #b3 => 34
Register #b4 => df
Register #b5 => a5
Register #b6 => 25
Register #b7 => 0
Register #b8 => 30
Register #b9 => 0
Register #ba => 60
Register #bb => ff
Register #bc => 0
Register #bd => 0
Register #be => 0
Register #bf => 0
Register #c0 => 0
Register #c1 => 0
Register #c2 => 0
Register #c3 => 0
Register #c4 => 0
Register #c5 => 10
Register #c6 => 14
Register #c7 => 0
Register #c8 => 2
Register #c9 => 3
Register #ca => 0
Register #cb => 1
Register #cc => 2
Register #cd => 0
Register #ce => 0
Register #cf => 70

Best Regards,
Aba abuchatzira

attachments.zip
  • Hi-

    I moved this question to the Video community.  Please continue the discussion here.

    Thanks,

    AndyR

    EngineerZone Community Manager

  • Hello Aba,

         The CTS values in R0x04, R0x05 and 0x06 look strange, but they are internally generated - very odd. You  may want to read these registers several times and see if they are changing wildly. For this application, I would expect them to read: 0x01, 0x22, 0x0A for a value of the 20-bit CTS of 74250d. There will be some small changes, but the value in there now of 0x00, 0x0B, 0xE7 is entirely too small.  This may be an indication that the audio clock has reflections on it. Looking at the 'scope output, it appears there is quite a bit of overshoot and undershoot. The AD9889B is sensitive to this in the audio channels, and I would recommend that they insert a series resistor for the SCLK line of about 100 ohms. Another option would be to lower the drive strength of the audio clock to reduce these reflections.

    Best.

    Chris

  • This question has been assumed as answered either offline via email or with a multi-part answer. This question has now been closed out. If you have an inquiry related to this topic please post a new question in the applicable product forum.

    Thank you,
    EZ Admin