4 Replies Latest reply on Oct 5, 2015 1:32 PM by jerome.bolduc

    FX3 I2S Support

    jed.althouse

      I would like to use the FX3 for an audio application, but I need an I2S receiver.  The datasheet indicates that the I2S interface only operates as a transmitter.  Additionally, I need to support a sample rate of 22.05 KHz in addition to 32, 44.1, and 48 KHz.  Has anyone implemented an I2S receiver on the FX3?  Is this even feasible?

        • 1. Re: FX3 I2S Support
          jerome.bolduc

          I'm trying to develop this type of interface but I have some issues even using the FX3 eval board. When using the cyusbi2sdmamode example, the FX3 can generate the MCLK at 12.288MHz when using i2sCfg.sampleRate = CY_U3P_I2S_SAMPLE_RATE_48KHz. 

             

          Unfortunately, I do not get any other clocks (I2S_CLK, I2S_WS) and I2S_SD is static. These are outputs... 

             

          I don't know how to make them work for now.

             

          I tried to use the Control Center in order to send data through the USB endpoints, transfers are successful but there is no toggling on these lines. These lines are floating for now because I don't have access to a codec.

             

          Any ideas why this would be?

             

          Jérôme

          • 2. Re: FX3 I2S Support
            Madhu Lakshmipathy

            Hi,

               

            1) One way for making FX3 to receive i2S data is to use the SPI Interface, There should be 3rd party i2S spi convertor on the SPI Interface which can be used to receive i2S data.

               

            2) Yes. You need to have the device connected on I2S Lines to make these lines toggle.

               

            Regards,

               

            - Madhu Sudhan

            • 3. Re: FX3 I2S Support
              jerome.bolduc

              Hi,

                 

              1) There is no way to make the I2S working without using a SPI to I2S converter? We already use the GPIF interface in 32bit mode and SPI is not available. Why there are dedicated pins for I2S on the FX3 chip if we have to use the SPI interface? We want to send audio data from the host to the FX3 on the USB link and then output i2s signals from FX3 to external codec. Is that possible with the FX3?

                 

              Regards,

                 

              Jérôme

              • 4. Re: FX3 I2S Support
                jerome.bolduc
                        Hello, I finally found a way to make the i2s interface working. In order to enable LRCLK/SCLK and to see data on the SD line, you must L 1) send data on OUT endpoint 1 2) send data on OUT endpoint 2 After sending the data on endpoint 2, you will be able to see data on the SD line using a scope and also see the clock outputs. If it helps even one single person, it will be worth it. Jérôme