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PCM9211: RXIN0 and RXIN1 that is coaxial inputs are not working.

John Maniraj
Prodigy 90 points
Part Number: PCM9211

Hello,

In my audio application the ADC portion and the optical inputs are working fine, but the coaxial inputs are not working. The voltage level from the DVD player seems to meet the 200mV minimum level, the input signal is terminated with a 75 ohm resistor and coupled to the PCM9211 through a 100nF capacitor as shown in a reference design. In one input I raised the level to about 500mV by changing the resistor to 300ohms it still wont work. The Coaxial power supply is turned on by writing 0x00 and 0x01 respectively to register 0x34. I think it worked once but after that it is not decoding the coaxial inputs.

Is there any other register I should set.

Regards,

John.

Mercy Electronic and Electrical Industries.

Bangalore, India.

  • 0
    TI__Expert 5645 points
    Hi John,
    Welcome to e2e Forum!

    By default, the PCM9211 has default routing function which routes RXIN2 as DIR input and you will have MAIN OUTPUT PORT configured in AUTO mode and hence you will have RXIN2 input (S/PDIF) routed to I2S output stream on MPO.

    I strongly recomment using the GUI that was provided w the EVM to configure the RXIN0 or RXIN1 inputs to suitable output port or MPIO ports using the easy-to-use interface. Thanks.

    Best regards,
    Ravi
  • 0 in reply to Ravi Patil
    Prodigy 90 points

    Hello Ravi,

    Thanks for the quick reply.

    I have configured the MAIN OUTPUT PORT in manual mode by writing 0x22 for ADC input and 0x11 for DIR input.

    ADC input, Optical1 and Output2 are working neatly without any problem.

    I really like this chip.

    Many Japanese audio companies are using this chip. In one AV receiver 2 of PCM9211 is used but they are not using the RIXN0 and RIXN1, instead they are buffering with a 74HC04 and giving to the other RIXN inputs like RIXN4 etc. Many other audio manufacturers are also doing the same.

    I think RIXN0 and RIXN1 are having serious problems.

    If not please offer a solution, other wise I will follow their method and redesign my boards, as I said I really like this chip.

    Regards,

    John.

  • 0 in reply to John Maniraj
    TI__Expert 5645 points
    John,
    Glad to hear you do like PCM9211.
    I have configured the device w RXIN0 and RXIN1 on my bench several times and have had no issues. Let me share the configuration that you can use to receive S/PDIF input on RXIN0/1 and convert it to I2S output stream on MPO.

    Best regards,
    Ravi
  • 0 in reply to Ravi Patil
    Prodigy 90 points

    Ravi,

    Thank you very much, I was eagerly waiting for your reply.

    Please do share the configuration file, where to download or email to mercyelectronic@gmail.com

    By the way I am not using your demo board, I have designed my own commercial board, every thing is working fine except coaxial inputs and I also delivered the boards without the coaxial inputs working.

    I will try your configuration and give you the results.

    Thanks.

    John.

  • 0 in reply to John Maniraj
    TI__Expert 5645 points
    Hi John,
    please find the script below to route the S/PDIF in on RXIN0 to MPO...Thanks.

    #**************************************
    # Script for SPDIF-->RXIN0-->DIR-->MainOutput,
    #
    #1, Chose RXIN0 to DIR
    #2, Active DIR
    #3, Chose DIR output as Mainoutput's source.
    #**************************************
    #System RST Control
    w 80 40 33
    w 80 40 C0

    #*********************************************************
    #-------------------------------Start DIR settings------------------------------------------------------

    #REG 34h DIR Input Biphase Signal Source Select and RXIN01 Coaxial Amplifier
    #--PWR down amplifier, Select RXIN2
    #w 80 34 C2
    #--PWR up amplifier, select RXIN0
    w 80 34 00
    #--PWR up amplifier, select RXIN1
    #w 80 34 01
    #------------------------------------ End DIR settings---------------------------------------------------

    #***********************************************************
    #---------------------------------Start MainOutput Settings-----------------------------------------
    #MainOutput
    #REG. 6Ah, Main Output & AUXOUT Port Control
    w 80 6A 00

    #REG. 6Bh, Main Output Port (SCKO/BCK/LRCK/DOUT) Source Setting
    w 80 6B 11

    #REG. 6Dh, MPIO_B & Main Output Port Hi-Z Control
    w 80 6D 00
    #***********************************************************
    #------------------------------------ End MainOutput settings-----------------------------------------

    Best regards,
    Ravi
  • 0 in reply to Ravi Patil
    Prodigy 90 points

    Ravi,

    I followed your above register values for the PCM9211 as shown below:

    PCM9211WriteByte(PCM9211_SYS_RESET,0x33);//0x40 # Reset and ALL Function Power Down
    PCM9211WriteByte(PCM9211_SYS_RESET,0xC0);//0x40 # Set Normal Operation
    PCM9211WriteByte(PCM9211_DIR_INP_BIPHASE,0xC2);//0x34 Optical1, default=0xC2;
    PCM9211WriteByte(PCM9211_DIR_INP_BIPHASE,0x00);//0x34 Coaxial 1, default=0xC2;
    PCM9211WriteByte(PCM9211_DIR_INP_BIPHASE,0x01);//0x34 Coaxial 2, default=0xC2;
    PCM9211WriteByte(PCM9211_MAIN_AUX_MUTE,0x00);//0x6A  default=0x00
    PCM9211WriteByte(PCM9211_MAIN_OUT_SOURCE,0x11);//0x6B default=0x00
    PCM9211WriteByte(PCM9211_MPIO_B_MAIN_HIZ,0x00);//0x6D  default=0x00
    The results are the same, coax inputs are not working but the optical inputs are working fine.
    Anyway I am designing a new board and I will be using the RXIN4 and RXIN5 with a 74LVC buffer for coaxial inputs.
    Thanks and Regards,
    John