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About PCM1863

Other Parts Discussed in Thread: PCM1865, PCM1864, PCM1863

Hi TI experts, 

I am studying the features of the ADC ( PCM1863 ). I hope It can work fine for my system efficiently with its features. 

I have some analog input to a ADC to obtain I2S signal and I need to route the I2S signal to other applications in the same time. And I also want to input I2S signal to ADC. So I want to know deeper about the DIN and DOUT 2 features of PCM1863

Case 1 : In master mode : Analog input and MCLK is provided externally,  Let PCM1863 generate BCK, LRCK, and  Data to DOUT_pin.

Questions 1 : According to the spec, I can obtain through GPIO 0 or 1 or 2 or 3 pins by set it as DOUT 2 while DOUT is in used ? 

Questions 2 : If above function is available, can I also obtain the BCK & LRCK for DOUT 2 by routed them from BCK & LRCK output pin while DOUT is in used with the clocks ? 

Questions 3 : If Analog signal is input, Can I obtain the data from DOUT_pin & DOUT 2 through GPIO,1,2,3 at once and and obtain the BCK & LRCK for DOUT 2 by routed them from BCK & LRCK output pin while DOUT is also used with the clocks ?

Case 2 : In master mode :  NO analog input, but I2S Data input only through GPIO 0 as DIN , and MCLK is provided externally

Question 1 : Can I2S data input through GPIO 0 or 1 or 2 or 3 pins by set it as DIN and I2S data output through DOUT_pin , meanwhile the BCK & LRCK is generated internally by provided external MCLK ? 

Question 2 : If above function is available, will the DATA, BCK, LRCK be synchronised correctly ?

Question 3 : If the I2S data is input to GPIO 0 by set it as DIN, Can I obtain the data from DOUT_pin & DOUT 2 through GPIO 1,2,3 at once and and obtain the BCK & LRCK for DOUT 2 by routed them from BCK & LRCK output pin while DOUT is also used with the clocks ?

I appreciate your advice, have a good day. 

Fai 

  • Hi Fai,

    To use DOUT2 you will need to use a 4 channel part either the PCM1864 or PCM1865. So the PCM1863 cannot use DOUT2.

    If you were to use a four channel part then the answers would be the following:

    Case 1: All Q's:

    Yes, DOUT 2 will work in all of these situations while DOUT is also working (both will output the same data). For both DOUTs you will use the same clocks from BCK and LRCK. Just to clarify, DOUT will only output on the DOUT pin, DOUT2 is able to be output on the GPIO pins.

    Case 2:

    Q1: DIN can be input on all GPIO pins except GPIO1. Yes, the part can still be a maser and have I2S input on DIN, if the source of the DIN is in slave mode running off the PCM186X clocks.

    Q2: If you are driving the source of the I2S with the LRCK and BCK from the PCM186X then the data will be synchronous.

    Q3: This seems a bit complicated  but I will say these points-

    -For any data in or out of the part, they need to use the clocks that are either being input to LRCK and BCK pins or being output from them.

    -There is no scenario that DOUT2 is not available, unless all the GPIO pins are used.

    -The device can handle all 3 in/outs working at once (DOUT, DOUT2, and DIN)

    Justin

  • Hi Justin, 

    thank you for your explanation, but I am still confused in some points...

    1) the simplified block diagram_Spec P.2, shows that DOUT_2 is available in 1863 & 1865. Is it correct ? or this is the mistake on the Spec ? ( please see the red highlighted below : captured from Spec P.2 ) 

    2) you mentioned that : (DIN can be input on all GPIO pins except GPIO1). According to the Spec P.76~78 (Page 0 / Register 16 (Hex 0x10) & Register 17 (Hex 0x10) ) it shows GPIO 0,1,2,3 are all available for DIN or DOUT_2 ? Is it correct ? or this is the mistake on the Spec ? 

    3) 1863 & 1865 both's GPIO 0,1,2,3 are also available for DIN or DOUT_2 ?

    4) Can I use different GPIO pin for DIN and DOUT_2 in once ? (e.g. GPIO_0 for DIN meanwhile GPIO_1 & 2 & 3 for DOUT_2)

    5) In master mode (when  there is NO analog to input)  and I just input Audio Data to DIN only without BCK & LRCK ) ; Will DOUT & DOUT_2 's audio data be synchronised automatically with the BCK & LRCK output ? 

    Thank you very much

    Fai 

    Thank you very much

    Fai