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PCM9211: SPDIF output is not detected

Chase Jeong
Mastermind 7555 points
Part Number: PCM9211

Tool/software:

Dear TI experts,

My customer now tests PCM9211 on their own PCB. basic schematic is as below;

1. I2S Input :

RXIN5/ABCKI0 - DSP_HOST_BCK

RXIN6/ALRCKI0 - DSP_HOST_LRCK

RXIN7/ADIN0 - DSP_HOST_SD0

2. SPDIF output :

MPO0

3. Register settings : set 0x33 to address 0x60

TXSSRC[2:0]: DIT System Clock Source Select               - 011: AUXIN0

TXPSRC[2:0]: DIT Bit Clock, LR Clock, Data Source Select - 011: AUXIN0

4. I2S Data format :

BCK  2.8225MHz

LRCK 44.1KHz

The problem is, SPDIF output is not detected.

They set 0x03 to address 0x60 then SPDIF output is detected and checked PLL Lock in connected external amplifier, but no sound is detected.

They suspected that SCK is not connected RXIN4/ASCKI0 so they think some settings should be different.

Could you guide me to debug this situation? I attach the schematic review thread 3 months ago for your convenience.

https://e2e.ti.com/support/audio-group/audio/f/audio-forum/1455951/pcm9211-please-review-the-schematic-of-pcm9211/5585210#5585210

Best regards,

Chase

  • 0
    TI__Mastermind 30711 points

    Hi Chase,

    By going through the description, I think  the following is  happening :   in slave slave mode,  they have to provide the SCK  according to  Table 7-10. Typical Audio Sampling, BCK, and SCK Frequencies

    When they write 0x33 for register h60, then the DIT SCK source is assigned to be from AUX input and they need to provide the SCK . However with 0x03  , the DIT SCK selection is automatic and it seems it is using the ADC SCK .  

    Also if they see SPDIF output- but no sound after the external amplifier, then I would send a known good s/pdif signal directly to the external amplifier and see if there is the  sound ( by doing this, they verify if issue is the generated format  of the output) .

    Regards,

    Arash

  • 0 in reply to Arash Loloee
    Mastermind 7555 points

    Dear Arash,

    Thank you for your support.

    My customer said that they checked the output sound by providing SCK. (modified customer's PCB using wires.)

    And they still have a question ;

    Is there any way to check the output sound not providing external SCK but just make SCK internally(PCM9211 itself)?

    Please check this issue. Thanks.

    Best regards,

    Chase

  • 0 in reply to Chase Jeong
    TI__Mastermind 30711 points

    Hello Chase,

    Section 7.3.8.5.3  explains that  during normal ADC operation, the system clock (SCK) is sourced within the PCM9211 (i.e.  the oscillator circuit SCK). Since the PCM data (SCK, BCK, LRCK, and Data) are routed directly out to MPIO_C,  I think you may be able to use this SCK and feed it back as external sck. 

    The onboard PLL generates a system clock that synchronizes with the input biphase signal. The generated system clocks from the PLL can be set to fixed multiples of the input S/PDIF frequency. Register 30h/PSCK[2:0] can configure the output clock to 128fS, 256fS or 512fS.

    If you don't want to provide external SCK yourself, options are limited.

    Regards,

    Arash