1 Reply Latest reply on Oct 28, 2020 12:41 AM by RodolfoG_11

    PSoC6 PDM to PCM

    MaWo_2683956

      I connected a PDM Mic(IM69D120) with my PSoC6, I want to save the PCM data to RAM by DMA, and I use the sample code CE220762,

      but I found when I cutoff the power supply of MIC, and there was no data on PDM Data line, but DMA could still get the data from RX_FIFO_RD,

      Why the PDM data line no data but DMA can still get the data from RX_FIFO_RD?

      Hardware:PSoC63

      Software:CE220762 – PSoC 6 MCU PDM to I2S Example

      Mic:infineon  IM69D120

      PDM_data.jpg

      PDM_recorded_data.jpg

        • 1. Re: PSoC6 PDM to PCM
          RodolfoG_11

          The clock signal that goes to the PDM mic is generated by the PSoC. The PDM/PCM block itself does not know if the microphone is powered or not. As long the block is enable, it generates the PDM clock and expect to read back some data from the PDM Data line.

           

          If you want to stop sampling the PDM mic when it is OFF, perhaps you can connect the PDM mic VDD as an input to the PSoC. If the input is HIGH, you know the mic is ON. If it is low, it it is OFF, so simply disable the PDM/PCM block.

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